ultrasonics in endodontics: a review of the literature · 2012-06-05 · ultrasonics in...

UGa

ADbeacaotttthssnTpdm8

KE

oi

Eg0

Ed

Review Article

J

ltrasonics in Endodontics: A Review of the Literatureianluca Plotino, DDS,* Cornelis H. Pameijer, DMD, DSc, PhD,† Nicola Maria Grande, DDS,*nd Francesco Somma, MD, DDS*

TncHtieiMcbhi

wbhs

nmmbwm

badefppwhos

asmsc

w

bstracturing the past few decades endodontic treatment hasenefited from the development of new techniques andquipment, which have improved outcome and predict-bility. Important attributes such as the operating mi-roscope and ultrasonics (US) have found indispensablepplications in a number of dental procedures in peri-dontology, to a much lesser extent in restorative den-istry, while being very prominently used in endodon-ics. US in endodontics has enhanced the quality ofreatment and represents an important adjunct in thereatment of difficult cases. Since its introduction, USas become increasingly more useful in applicationsuch as gaining access to canal openings, cleaning andhaping, obturation of root canals, removal of intraca-al materials and obstructions, and endodontic surgery.his comprehensive review of the literature aims atresenting the numerous uses of US in clinical endo-ontics and emphasizes the broad applications in aodern-day endodontic practice. (J Endod 2007;33:

1–95)

ey Wordsndodontics, innovations, ultrasonics

From the *Department of Endodontics, Catholic Universityf Sacred Heart, Rome, Italy; and the †School of Dental Med-

cine, University of Connecticut, Farmington, CT.Address requests for reprints to Gianluca Plotino, DDS, Via

leonora Duse, 22–00197 Rome, Italy. E-mail address:[email protected]/$0 - see front matter

Copyright © 2007 by the American Association ofndodontists.oi:10.1016/j.joen.2006.10.008

OE — Volume 33, Number 2, February 2007

he use of ultrasonics (US) or ultrasonic instrumentation was first introduced todentistry for cavity preparations (1–3) using an abrasive slurry. Although the tech-

ique received favorable reviews (4, 5), it never became popular, because it had toompete with the much more effective and convenient high-speed handpiece (6).owever, a different application was introduced in 1955, when Zinner (7) reported on

he use of an ultrasonic instrument to remove deposits from the tooth surface. This wasmproved upon by Johnson and Wilson (8), and the ultrasonic scaler became anstablished tool in the removal of dental calculus and plaque. The concept of using USn endodontics was first introduced by Richman (9) in 1957. However, it was not until

artin et al. (10 –12) demonstrated the ability of ultrasonically activated K-type files tout dentin that this application found common use in the preparation of root canalsefore filling and obturation. The term endosonics was coined by Martin and Cunning-am (13, 14) and was defined as the ultrasonic and synergistic system of root canalnstrumentation and disinfection.

Ultrasound is sound energy with a frequency above the range of human hearing,hich is 20 kHz. The range of frequencies employed in the original ultrasonic units wasetween 25 and 40 kHz (15). Subsequently the so-called low-frequency ultrasonicandpieces operating from 1 to 8 kHz were developed (16 –21), which produce lowerhear stresses (22), thus causing less alteration to the tooth surface (23).

There are two basic methods of producing ultrasound (24 –26). The first is mag-etostriction, which converts electromagnetic energy into mechanical energy. A stack ofagnetostrictive metal strips in a handpiece is subjected to a standing and alternatingagnetic field, as a result of which vibrations are produced. The second method is

ased on the piezoelectric principle, in which a crystal is used that changes dimensionhen an electrical charge is applied. Deformation of this crystal is converted intoechanical oscillation without producing heat (15).

Piezoelectric units have some advantages compared with earlier magnetostrictive unitsecause they offer more cycles per second, 40 versus 24 kHz. The tips of these units work inlinear, back-and-forth, “piston-like” motion, which is ideal for endodontics. Lea et al. (27)emonstrated that the position of nodes and antinodes of an unconstrained and unloadedndosonic file activated by a 30-kHz piezon generator was along the file length. As a result theile vibration displacement amplitude does not increase linearly with increasing generatorower. This applies in particular when “troughing” for hidden canals or when removingosts and separated instruments. In addition, this motion is ideal in surgical endodonticshen creating a preparation for a retrograde filling. A magnetostrictive unit, on the otherand, creates more of a figure eight (elliptical) motion, which is not ideal for either surgicalr nonsurgical endodontic use. The magnetostrictive units also have the disadvantage that thetack generates heat, thus requiring adequate cooling (15).

Applications of US in EndodonticsAlthough US is used in dentistry for therapeutic and diagnostic applications as well

s for cleaning of instruments before sterilization (28), currently its main use is forcaling and root planing of teeth and in root canal therapy (15, 28, 29). The concept ofinimally invasive dentistry (30, 31) and the desire for preparations with small dimen-

ions has stimulated new approaches in cavity design and tooth-cutting concepts, in-luding ultrasound for cavity preparation (32).

The following is a list of the most frequent applications of US in endodontics, whichill be reviewed in detail:

1. Access refinement, finding calcified canals, and removal of attached pulp
stones
Ultrasonics in Endodontics 81

AA

ldmtpspt

gir

ft

asr

htap

peidooac(ccotow

mthse(pps

cc

R

trophstch

Fmte

Review Article

8

2. Removal of intracanal obstructions (separated instruments, rootcanal posts, silver points, and fractured metallic posts)

3. Increased action of irrigating solutions4. Ultrasonic condensation of gutta-percha5. Placement of mineral trioxide aggregate (MTA)6. Surgical endodontics: Root-end cavity preparation and refine-

ment and placement of root-end obturation material7. Root canal preparation

ccess Refinement, Finding Calcified Canals, and Removal ofttached Pulp Stones

One of the challenges in endodontics is to locate canals, particu-arly in cases in which the orifice has become occluded by secondaryentin or calcified dentin secondary to the placement of restorativeaterials or pulpotomies. With every access preparation in a calcified

ooth, there is the risk of perforating the root or, when incorrectlyerformed, of complicating each subsequent procedure. A lack of atraight-line access is arguably the leading cause of separation,erforation, and the inability to negotiate files to the radiographic

erminus (33).The introduction of the microscope, access burs, and US (34) has

reatly reduced these risks. Microscopic visualization and ultrasonicnstruments are a safe and effective combination to achieve optimalesults (35–37).

In difficult-to-treat teeth such as molars, US has proven to be usefulor access preparation, not only for finding canals, but also for reducinghe time and the predictability of the treatment (33, 34).

In conventional access procedures, ultrasonic tips are useful forccess refinement, location of MB2 canals in upper molars and acces-ory canals in other teeth, location of calcified canals in any tooth, andemoval of attached pulp stones (35–37).

There are numerous variations of rotary access burs available;owever, one of the more important advantages of ultrasonic tips is thathey do not rotate, thus enhancing safety and control, while maintaininghigh cutting efficiency. This is especially important when the risk oferforation is high.

The visual access and superior control that ultrasonic cutting tipsrovide during access procedures make them a most convenient tool,specially when treating difficult molars. When locating the MB2 canalsn upper molars, US is an excellent means for the removal of secondaryentin on the mesial wall (Fig. 1). When searching for hidden canals,ne should remember that secondary dentin is generally whitish orpaque, whereas the floor of the pulp chamber is darker and gray inppearance. US works well when breaking through the calcification thatovers the canal orifice. A troughing tip is a good choice for this taskFig. 2a,b). For these applications, bigger tips with a limited diamond-oated extension should be used during the initial phase of removingalcification, interferences, materials, and secondary dentin, as theyffer maximum cutting efficiency and enhance control while working inhe pulp chamber (Fig. 2c,d). The subsequent phase of finding canalrifices should be carried out with thinner and longer tips that facilitateorking in deeper areas while maintaining clear vision (33, 34) (Fig. 2e).

The diamond-coated tips used in orthograde endodontic treat-ent (Fig. 2a– e) have shown significantly greater cutting efficiency

han either stainless steel tips or zirconium nitride– coated tips, but theyave a tendency to break (38). Moreover, thinner diamond-coated tipseem to be able to transmit the oscillation of the ultrasonic unit morefficiently into dentin; this results in a more aggressive cutting action39). Ultrasonic cutting seems to be significantly influenced by theower setting (39), as larger fragments of dentin are removed at higherower (40), and by the ultrasonic unit type used (39). Therefore, care
hould be exercised while searching for canal orifices, as aggressive o
2 Plotino et al.

utting may cause an undesired modification of the anatomy of the pulphamber.

emoval of Intracanal ObstructionsClinicians are frequently challenged by endodontically treated

eeth that have obstructions such as hard impenetrable pastes, sepa-ated instruments, silver points, or posts in their roots (41). If end-dontic treatment has failed, these obstructions need to be removed toerform nonsurgical retreatment. Many instruments and techniquesave been reported (42, 43). They include appropriate burs (44);pecial forceps (45); ultrasonic instruments in direct or indirect con-act (46 – 49); peripheral filing techniques in the presence of solvents,helators, or irrigants (50); microtube delivery using mechanical ad-esion techniques (51); and different kits and extractors (52–54).

Ultrasonic energy has proven effective as an adjunct in the removal

igure 1. The orifice of the second mesiobuccal canal (MB2) in an upper firstolar was located (a) and enlarged (b). Dentine spur at the orifice was effec-

ively eliminated with the use of a diamond-coated ultrasonic tip, thus permittingasy location of the orifice of the canal.

f silver points, fractured instruments, and cemented posts (55). It has

JOE — Volume 33, Number 2, February 2007

ousnt

ctWtbermmp

csararli

S

srp

ifth

atrac

r7of(baspau(sdtp

prpstmas(

R

Fatttftssr rator

Review Article

J

ften been advocated for the removal of broken instruments because theltrasonic tips or endosonic files may be used deep in the root canalystem (56). Furthermore, the use of an ultrasonic endodontic device isot restricted by the position of the fragment in the root canal or theooth involved (57).

The prognosis of these cases mainly depends on the preoperativeondition of the periapical tissues (58, 59). For this reason an attempto remove broken instruments should be undertaken in every case (60).

hen these obstructions can be removed, successful treatment or re-reatment generally occurs (61). If an instrument can be removed orypassed and the canal can be properly cleaned and filled, nonsurgicalndodontics is a more desirable and conservative approach (62). Theemoval of an obstacle from a root canal must be performed with ainimum of damage to the tooth and the surrounding tissues (44). Toouch destruction of tooth structure will complicate the restorative

hase and as a result will most likely decrease the overall prognosis.Although it is possible to remove many fragments, a small number

annot be removed because of limited access, despite the use of ultra-onic tips (63) (Fig. 2f,g). When the obstacle prevents access to the rootpex, adequate preparation, disinfection, and obturation of the entireoot canal system are not possible. Straight-line access is essential andllows for maximum visibility of the metallic fragment (64). For thateason, the use of magnification (dental operating microscope oroupes) is essential, as it provides direct visualization with excellentllumination, allowing instrumentation at high magnifications.

eparated InstrumentsManagement of a broken instrument requires an orthograde or a

urgical approach. The three orthograde approaches are (a) attempt toemove the instrument; (b) attempt to bypass the instrument; and (c)repare and obturate to the fractured segment (65).

In most cases, removal of broken instruments from the root canals difficult and often hopeless (66). To date, no standardized procedureor the safe removal of fractured instruments exists, although variousechniques and devices have been suggested (67, 68). These techniques

igure 2. (a) The BUC-1 is an example of diamond-coated spreader tip of mediugroove in the mesial access wall to drop into MB2 canals, and quickly and care

ip and a water port for increased washing and cooling of the operative site. It ishe objective to remove it. (c) This diamond-coated pear tip is used to find canemporary and permanent cements, and posts. It creates a smooth, clean flat trouine cutting control when preparing a troughing groove and is less aggressive thaip with a diamond coating, which offers a side- as well as an end-cutting action.preader tip indicated for troughing and removal of broken instruments. (g) Aeparated instrument in the middle or apical third of the canal. (h) A spreaderemoval of calcifications, provisionals, cements, buildup materials, etc. (i) Vib

ave shown only limited success, while often causing considerable dam- d


ge to the remaining root (61, 68). Complications as a result of theseechniques include excessive loss of root canal dentin, ledging, perfo-ation, and extrusion of the fractured instrument fragment through thepex (69). Therefore, many techniques cannot be used in narrow andurved canals (61).

Over the years, different techniques have been proposed for theemoval of separated instruments from root canals (44, 57, 60, 63, 66,0 –72). Recent advances in endodontics have led to the developmentf techniques and devices designed specifically for the safe removal of

ractured instruments from deep within narrow curved root canals (73)Fig. 3). Ruddle (64, 71) proposed a technique for the removal ofroken instruments using Gates Glidden drills (size 3 or 4) to preparecircumferential “staging platform” at the coronal aspect of the ob-

truction (Fig. 4). Attention must be paid during preparation of a staginglatform, because a size 3 or 4 Gates Glidden may perforate or weakenroot, for instance the mesial (74, 75) and distal root (76) of mandib-lar molars, the distobuccal and mesiobuccal roots of maxillary molars77), and central and lateral mandibular incisors (77). Their use seemsafe in central and lateral maxillary incisors (77), maxillary and man-ibular canines (77), and mandibular premolars (78, 79). The litera-

ure is controversial with regard to maxillary premolars because of theirarticular anatomy (80 – 82).

Radiographic evaluation of the residual dentin thickness duringreparation of the platform can be misleading because of the inaccu-acy of radiographic interpretation. Overestimation may lead to over-reparation of the canal or root perforation (83). Recently, it has beenhown that preparation of staging platforms was best accomplished withhe use of modified LightSpeed files (84). The inability to see the instru-

ent with direct vision and the difficulty of creating a staging platform,s well as the use of US in curved roots, has contributed to a lack ofuccess in removing fractured instruments under these circumstances57, 61, 63, 69, 84).

oot Canal PostsNonsurgical endodontic retreatment of teeth restored with intrara-

gth that can be used for gross dentin removal, moving access line angles, cuttingnroofing pulp chambers. (b) The BUC-3 is similar to the BUC-1 with a sharperor chasing canals or for digging around a post or carrier-based obturator withmove coronal obstructions or restorative materials, or remove calcifications,groove that facilitates canal location. (d) This diamond-coated ball tip providesear tip shown in c, yet it has the same clinical indications. (e) A classic spreaders needed to flare the walls of a troughing groove in an axial direction. (f) A fine-fine spreader tip used for extremely fine and deep troughing or removal of aigned for multiple uses such as instrument or silver point removal, troughing,

tip specifically designed for post removal.

m lenfully uused fals, reghing

n the pThis i

n extratip des

icular posts continues to present a challenge because of the inherent


dti8

p(pmwbv

Fvt

Ffcforesin composite core buildup (c).

Review Article

84 Plotino et al.

ifficulties of removing posts without weakening, perforating, or frac-uring the remaining root structure (85– 88). Many techniques andnstruments have been described to aid in the removal of posts (52, 85,8 –94).

US has provided clinicians with a useful adjunct to facilitateost removal with minimal loss of tooth structure and root damage48, 95–97). Many studies have focused on the removal of metallicosts; however, retreatment of fiber-reinforced composite posts ce-ented with adhesive systems presents a new challenge in cases inhich endodontic treatment has failed (98). Different bur kits haveeen proposed to remove fiber posts (99, 100); however, the preser-ation of maximum root structure requires the use of specific ultrasonic

igure 4. Gates Glidden bur modified by cutting it at the maximum diameteriewed from an apical (a) and lateral direction (b). This permits the prepara-

igure 3. NiTi rotary instrument separated in the distobuccal canal of an upperirst molar (a). The fragment was removed using ultrasonic tips, and the rootanals were successfully negotiated to the apex (b) and cleaned, shaped, andilled (c). The tooth was subsequently restored with two fiber-reinforced posts,ne in the palatal and one in the mesiobuccal canal, followed by a dual-cure

ion of a platform at the extruded portion of the fragment to be removed.


tptpdRdad

twdtti

vet(lcecctwc(cr

ft1l8

(gidBtsr

lutlt

ped(rpcoutue2bwttimd(e

FwwucMd

Review Article

J

ips (Fig. 2h) and adequate magnification. The disruption of the com-osite structure through the action of ultrasonic vibration seems to behe most effective technique in fiber post removal (101). Esthetic whiteosts are more difficult to remove because their color matches that ofentin, whereas the black carbon fiber posts clearly contrast to dentin.emoval is done in a dry field using a continuous stream of air withirect vision of the ultrasonic tip and the coronal portion of the post,lternated by air and water spray to clean the remnants of fibers andentin.

It is important that the entire composite material that was used inhe luting procedure be removed. If the adhesive procedure was doneell, removal of the tenaciously attached adhesive materials will beifficult, and high magnification must be used to guide the ultrasonic tipo selectively remove the attached composite material. If the ultrasonicip leaves behind gray streaks, it is a clear indication that resin compos-te or resin composite cement is still present.

The need of consuming fiber posts is based on the fact that theiscoelastic nature of composite resin dampens vibrations and adsorbsnergy (102). Conductance of vibration forces within a post is propor-ional to the square root of the modulus of elasticity of the post material103). Therefore, a fiber-reinforced composite post with a significantlyower modulus of elasticity than stainless steel or titanium (104, 105)onducts vibration less efficiently (97). Combining the low modulus oflasticity of post materials with composite resin cements causes ahange in the effectiveness of US as an aid in post removal (97). Resinements are not friable and do not tend to produce microfractures dueo ultrasonic vibration (106). It was suggested that the absence of aater spray seems to increase the action of US when applied to postsemented with resin cements, possibly because of the increase in heat107). This is helpful information, as it has been observed that theapacity of adhesion of a resin cement, and consequently mechanicaletention, gradually reduces with the number of thermal cycles (108).

Several studies point to the fact that ultrasonic vibration of postsacilitates their removal while conserving tooth structure and reducinghe possibility of fractures or root perforations (55, 86 – 88, 95, 102,09). Several studies have demonstrated a reduction in tensile failureoads of intraradicular-cemented posts after ultrasonic vibration (55,6 – 88, 95, 102, 107, 109 –116). Other studies did not find a difference

igure 5. Preoperative image (a) and radiograph (b) of a mandibular first molaith pain and swelling. The preoperative diagnostic radiograph revealed signsas sectioned (c) and removed (d), and the gold cast posts were separated toltrasonic tip to disrupt the cement seal (h). This clinical image revealed two pompacted with an ultrasonic tip (i). Root canals were filled with gutta-perchaTA to enhance the seal of the perforations (m). Postendodontic preprosthet

ual-cure resin composite buildup material (n).


97, 117, 118). Bergeron et al. (119) and Garrido et al. (107) sug-ested that heat generation might have been responsible for the increasen retention after ultrasonic vibration, as no water-cooling was useduring the procedure. As to the fiber-reinforced root canal posts,ergeron et al. (119) and Hauman et al. (97) further hypothesized that

he lower modulus of elasticity of the titanium compared with that of thetainless steel may have been responsible for the ineffectiveness of US ineducing post retention.

Using US involves the initial removal of restorative material(s) anduting cement around the post, followed by application of the tip of anltrasonic instrument to the post (Fig. 5a– g). Ultrasonic energy is

ransferred through the post and breaks down the cement until the postoosens (107) (Fig. 5h). This method of post removal minimizes loss ofooth structure and decreases the risk of tooth damage (48, 95, 97).

When removing a post, it is critical to break the seal between theost and the tooth structure. It has been recommended to reduce thextraradicular portion of the post to the same diameter as the intrara-icular portion (118) to reduce the necessary tension to remove it114). In some cases this can be accomplished with a surgical-lengthound bur, a technique not without danger. Once trephining around theost has been done, a basic spreader tip placed in the trough is a goodhoice (Fig. 2h). This will further break down the integrity of the cementr resin, usually resulting in loosening of the post. Alternatively, theltrasonic tip can be placed on the post or on a hemostat that is clamped

o the post. The tip should not be too thin, because small-diameterltrasonic instruments are weak and more predisposed to breakage,specially when they are used for a long time on a resistant material (Fig.i). On the other hand, the tip should not be too large, because it muste kept in intimate contact with the post when it is moved counterclock-ise around the post (98) (Fig. 2a,b). Usually, the ultrasonic unit is set

o the maximum power level (97, 107, 111, 114, 119, 120). Becausehis generates heat, especially over longer periods of application, cool-ng with a water spray is of the essence. When heat is transferred to a

etal post, it can be transferred to the periodontal ligament, causingamage (121), even with the use of a piezoelectric ultrasonic handpiece122). There is in vitro evidence that application of US to metal posts,ven with adequate water-spray cooling (120), can lead to rapid in-

three gold cast posts and cores and full-crown coverage. The patient presentediolucency in the furcal area toward the mesial root. The metal-ceramic crownte their removal (e, f). The three posts were removed (g) by vibrating with antions in the mesial root canal (h). Perforations were repaired using gray MTAaler (l), and the coronal portions of the mesial canals were further filled withoration was performed using a fiber-reinforced post in the distal canal and a

r withof radfacilitaerforaand seic rest


co

uttpaatp

dah

dqiibttcaHs

S

pt

otc

sostifmf

tc

osvsepshtwro

ts

I

f(m(ddhttlpagcdp

o(fuir

smpcJtc

1swif

alusaim

pgctpW

sdt

Review Article

8

reases in temperature of the root surface, causing damage to the peri-dontal ligament (122, 123).

The relative ease of removing prefabricated parallel posts with these of US is probably related to their design, as they do not adapt well tohe coronal third of most root canals. This allows for easy breakdown ofhe cement in the coronal third and subsequent shifting of the fulcrumoint toward the apical end of the post. As the fulcrum point shiftspically, the ultrasonic vibrations start to move the post about this pointnd within the space created in the coronal third. This movement helpso break down the cement/post interface toward the apical end of theost in conjunction with breakdown within the cement itself.

In cases in which the post has a tight fit with adequate length andiameter, and with limited access to the coronal portion, the effect of USlone may be limited or even ineffective. In these situations the clinicianas to consider other treatment options (118).

In a clinical study by Smith (112), the mean time required toislodge posts with an ultrasonic instrument was approximately one-uarter of that reported for in vitro studies (97). This may be explained

n that, in a clinical setting, the reason for removing posts is due tonfected root canals frequently caused by coronal leakage, leading toreakdown of the cement, retaining both the coronal restoration andhe post. In clinical practice posts should therefore be easier to removehan under laboratory conditions (97). Clinically, after removing allircumferential restorative materials, the majority of posts can be safelynd successfully removed within approximately 10 minutes (102, 110).owever, certain posts resist removal, even after 10 minutes of ultra-

onic activation (98).

ilver Points and Fractured Metallic PostsSeveral studies have shown that retrieval of silver cones can be

erformed with traditional techniques using hand instruments and par-icular devices and extractors (45, 50, 51, 66, 124, 125).

Other techniques utilize ultrasonic energy in cases of intracanalbstruction and consume the obstruction with particular ultrasonicips. This predominantly applies to silver points inside canals, whichannot be bypassed by conventional methods (62, 126).

The traditional clinical procedure to remove root canal posts orilver points fractured at the orifice consists of exposing the coronal partf the obstacle by cutting an estimated 2.0-mm trough around the ob-tacle with a fine diamond bur. The tip of an ultrasonic unit (Fig. 2h) ishen applied to the side of the post fragment at full power with waterrrigation. Ultrasonic vibration is applied for periods of a few secondsollowed by drying with compressed air. This should lead to dislodge-

ent of the fragment of the post, which can then be removed with a fineorceps (47, 112, 127).

When an obstruction allows for limited access to the coronal por-ion of the point, a more conservative approach would be to try toonsume it instead of consuming the surrounding dentin (62, 126).

An important point to realize when removing silver points is thatne is dealing with a very soft material. Any misdirection of a bur canever the point, complicating the case even further. US has proven to beery helpful in the removal of these points. Simply trough around theilver point with an ultrasonic spreader tip (Fig. 2f,g) and carefullyliminate dentin while following the long axis, taking care not to cut theoint. The space created around the silver point will usually loosen theilver point, which can then be removed with a Steiglitz forceps oremostat. At all times, the use of intraoral radiographs is recommendedo confirm the position and the remaining length of the obstruction, asell as the thickness of canal walls (47, 64). The time required for

emoval of a post or silver point is influenced by the nature of the
bstruction, its diameter, and location. Semiprecious metals take more U
6 Plotino et al.

ime than precious metals. Large-diameter posts are more time con-uming compared with narrow ones (62).

ncreased Action of Irrigating SolutionsThe effectiveness of irrigation relies on both the mechanical

lushing action and the chemical ability of irrigants to dissolve tissue128, 129). Furthermore, the flushing action of irrigants helps to re-ove organic and dentinal debris and microorganisms from the canal

130). The flushing action from syringe irrigation is relatively weak andependent not only on the anatomy of the root canal but also on theepth of placement and the diameter of the needle (128, 131, 132). Itas been shown that irrigants can only progress 1 mm beyond the tip of

he needle (133). An increase in volume does not significantly improveheir flushing action and efficacy in removing debris (134, 135). Inarger apical canals, the debridement and disinfection of canals is im-roved (128). However, thorough cleaning of the most apical part ofny preparation remains difficult (136). Using thinner needles (30auge) may facilitate reaching the apical area directly. Although con-lusive evidence is still lacking, the introduction of slim irrigating nee-les with a safety tip placed to working length or 1 mm short of it is aromising approach to improve irrigant efficacy.

The only effective way to clean webs and fins is through movementf the irrigation solution (137), as they cannot be mechanically cleaned138). US is a useful adjunct in cleaning these difficult anatomicaleatures. It has been demonstrated that an irrigant in conjunction withltrasonic vibration, which generates a continuous movement of the

rrigant, is directly associated with the effectiveness of the cleaning of theoot canal space (22, 137–142).

Acoustic streaming, as described by Ahmad et al. (140), has beenhown to produce sufficient shear forces to dislodge debris in instru-ented canals. When files were activated with ultrasonic energy in a

assive manner, acoustic streaming was sufficient to produce signifi-antly cleaner canals compared with hand filing alone. Similarly,ensen et al. (143) recommended a vibrating file of small size subjectedo a high power setting, as smaller files will be less likely to contact theanal walls.

The flushing action of irrigants may be enhanced by using US (15,32, 140, 144, 145). This seems to improve the efficacy of irrigationolutions in removing organic and inorganic debris from root canalalls (12, 129, 132, 142, 143, 145–158). A possible explanation for the

mproved action is that a much higher velocity and volume of irrigantlow is created in the canal during ultrasonic irrigation (129).

The tissue-dissolving capability of solutions with a good wettingbility may be enhanced by US if the pulp tissue remnants and/or smearayer are wetted completely by the solution and become subject to theltrasonic agitation (145, 159). US creates both cavitation and acoustictreaming. The cavitation is minimal and is restricted to the tip (160). Thecoustic streaming effect, however, is significant (161). In fact, the irrigants activated by the ultrasonic energy imparted from the energized instru-

ents, producing acoustic streaming and eddies (15, 140, 141).US can also improve disinfection of root canals (148, 149, 162–166),

robably because organic tissues entering the streaming field that isenerated are disrupted, as proposed by Walmsley (24). Ahmad (167)onfirmed that ultrasonically activated files produced streaming pat-erns close to the file, continuously moving irrigants around, therebyroducing shear stress, which can damage biological cells, as stated byilliams (168).

Although the number of surviving colonies was less when ultra-onic activation was used, no technique was able to ensure completeisinfection (130, 143, 161, 169, 170). Cameron (171) postulated that

here is a synergistic effect between sodium hypochlorite (NaOCl) and
S. The ability of NaOCl to dissolve collagen is enhanced with heat

(s

bn(cc

ctiSmIcos

rs1

smtteu

(p1

ovd

cmtsi

ce

U

titseasre

stt

sae

twtoanaccstubc

sposspsaafp

afd

wwp

P

Fc

Review Article

J

172); therefore, the effect of heat on the irrigant produced by ultra-onic action plays an important role (15, 173).

The effectiveness of hand syringe irrigation in narrow canals haseen questioned by several investigators (145, 174 –178). Narrow ca-als may also compromise the effectiveness of ultrasonic irrigation15, 144, 179), and when sonic or ultrasonic files are used in small,urved canals, they may bind, thus restricting their vibratory motion andleaning efficiency (180).

For irrigating solutions to be effective, they have to be in directontact with a surface (181). In small-diameter roots, irrigating solu-ions have difficulty reaching the apex of the tooth and therefore are leastnfluenced by activated irrigation (166, 182). Furthermore, van derluis et al. (183) have postulated that ultrasonic irrigation should beore effective in removing debris from root canals with greater tapers.

t appeared to be important to apply the ultrasonic instrument afteranal preparation had been completed (184). Furthermore, a freelyscillating instrument will cause more ultrasonic effects in the irrigatingolution than one that binds to canal walls (185).

US as an adjunct with various irrigating solutions contributes to theemoval of the smear layer (12, 145, 155, 176, 181, 186), however, iteems to be less effective in enhancing the activity of EDTA (154, 163,87–189).

Thirty seconds to 1 minute of ultrasonic activation seems to beufficient to produce clean canals (157), whereas others recommend 2inutes (142). Shorter passive irrigation time makes it easier to main-

ain the file in the center of the canal, thus preventing it from touchinghe canal walls (157). Syringe delivery of NaOCl every minute was asffective as a continuous flow of NaOCl during 3 minutes of passiveltrasonic irrigation in the removal of dentin debris (135).

For ultrasonic irrigation, the use of medium power was suggested171, 190 –192). It is of interest to note that a combination of low-ower US with NaOCl was not more effective than NaOCl alone (193,94).

Ultrasonic vibration can also be effective when touching the shankf a hand file inserted inside the canal. The hand file will transmitibrations to the irrigant inside the canal, but a greater risk for touchingentinal walls exists.

To prevent a dampening effect, sonic or ultrasonic files should notontact the canal walls; therefore, the use of smooth files is recom-ended (157). In contrast, ultrasonically activated stainless steel files

end to ledge and perforate canal walls because of their sharp cuttingurfaces (195) (Fig. 6). The use of a smooth wire during ultrasonicrrigation in vitro was as effective as a K-file in debris removal (196).

Furthermore, US as an adjunct with EDTA enhanced the canal wallleanliness after post space preparation in endodontically treated teeth,specially in the apical portion of the post space (197).

ltrasonic Condensation of Gutta-PerchaUltrasonically activated spreaders have been used to thermoplas-

icize gutta-percha in a warm lateral condensation technique. In somen vitro experiments, this was demonstrated to be superior to conven-ional lateral condensation with respect to sealing properties and den-ity of gutta-percha (198 –201). Ultrasonic spreaders that vibrate lin-arly and produce heat, thus thermoplasticizing the gutta-percha,chieved a more homogeneous mass with a decrease in number andize of voids and produced a more complete three-dimensional obtu-ation of the root canal system (201). This technique has also beenvaluated clinically with favorable results (202).

A number of obturation protocols have been described for ultra-onic condensation of gutta-percha: (a) ultrasonic softening of the mas-er cone followed by cold lateral condensation (198); (b) one or two
imes of ultrasonic activation after completion of cold lateral conden- p

ation (203); (c) ultrasonic activation after placement of each secondccessory cone (201); or (d) ultrasonic activation after placement ofach accessory cone (200, 204, 205).

Warm lateral condensation combines the advantage of having con-rol over the length of the root fill, similar to cold lateral condensation,ith the superior ability of a thermoplasticized material to replicate the

hree-dimensional shape of the root canal (201). From a practical pointf view, ultrasonic condensation of gutta-percha is quickly masterednd has several advantages over other warm lateral condensation tech-iques. It was observed that heat was generated only during ultrasonicctivation, and the plugger appeared to cool rapidly once activationeased (204). The size of the heat carrier (ultrasonic spreader) can behosen to match the diameter of the root canal, and the ultrasonicpreader can be curved to match the curvature of the root canal. Fur-hermore, gutta-percha does not stick to the ultrasonic file when theltrasonic unit is activated (198). Also, the low temperature producedy the unit at its lowest power setting may result in less volumetrichanges of gutta-percha upon cooling (206).

The obturation technique recommended when using the ultra-onic techniques (204, 205) consists of initial placement of a gutta-ercha cone to the working length followed by cold lateral condensationf two or three accessory cones using a finger spreader. The ultrasonicpreader is then placed into the center of the gutta-percha mass 1 mmhort of the working length and activated at intermediate power torevent charring of root surfaces and fracture of the ultrasonicpreader. After activation, the ultrasonic spreader is removed, and andditional accessory cone is placed, followed by energizing with thectivated ultrasonic spreader. This process is repeated until the canal isilled. During each subsequent step, the ultrasonic spreader should belaced slightly more coronally.

The ultrasonic spreader must be in the mass of gutta-percha forbout 10 seconds to achieve thermoplasticization. Leaving it in the canalor more than 10 seconds can produce a rise in temperature that isamaging to the root surface (204, 205).

In addition, it has been demonstrated that placement of sealersith an ultrasonically energized file promoted a better covering of canalalls with better filled accessory canals (evaluated by radiography) thanlacement of sealers with hand instruments (207, 208).

lacement of Mineral Trioxide Aggregate (MTA)Witherspoon and Ham (209) described the use of US to aid in the

igure 6. SEM image of the instrumentation grooves on the root canal wallsreated by an ultrasonic file (�1,150).

lacement of MTA. The inherent irregularities and divergent nature of


sdsMtcv(w

dfuwarmililtvr

arf

SR

nfdpa

s1wbcbtlHaocr

ffra

maritdbderrs

hsvacac(t

F

F

Review Article

8

ome open apices may predispose the material to marginal gaps at theentin interface. It was demonstrated that, with the adjunct of US, aignificantly better seal with MTA was achieved (210). Placement ofTA with ultrasonic vibration and an endodontic condenser improved

he flow, settling, and compaction of MTA. Furthermore, the ultrasoni-ally condensed MTA appeared denser radiographically, with feweroids (210). These results contradicted those of Aminoshariae et al.211), who concluded from an in vitro study that hand condensationas superior.

The recommended placement method consists of selecting a con-enser tip, then picking up and placing the MTA with the ultrasonic tip,ollowed by activating the tip and slowly moving the MTA material downsing a 1- to 2-mm vertical packing motion. Direct ultrasonic energyill vibrate and generate a wavelike motion, which facilitates movingnd adapting the cement to the canal walls (Fig. 5i–l). In a case ofepairing a defect apical to the canal curvature, Ruddle (41) recom-ends incrementally placing MTA deep into a canal, then shepherding

t around the curvature with a flexible trimmed gutta-percha cone uti-ized as a plugger. A precurved 15 or 20 stainless steel file is thennserted into the material and placed to within 1 or 2 mm of the workingength. This is followed by indirect ultrasound, which involves placinghe working end of an ultrasonic instrument on the shaft of the file. Thisibratory energy encourages MTA to move and conform to the configu-ations of the canal laterally as well as controlling its movement.

This technique was recommended initially for placing MTA in opennd diverging apices, but it can also be used to put the material inoot-end cavities, in perforations, and especially in perforations of theloor of the pulp chamber (Fig. 5i–n).

urgical Endodontics: Root-End Cavity Preparation andefinement and Placement of Root-End Obturation Material

Recent developments of new instruments and techniques have sig-ificantly enhanced the treatment outcome in apicoectomy with retro-illing (212). As the prognosis of endodontic surgery is highly depen-ent on good obturation and sealing of the root canal, an optimal cavityreparation is an essential prerequisite for an adequate root-end fillingfter apicoectomy (20, 213, 214).

oigure 7. Diamond-coated stainless steel ultrasonic surgical retrotips.

8 Plotino et al.

Root-end cavities have traditionally been prepared by means ofmall round or inverted cone burs in a microhandpiece. In the mid-980s, standardized instruments and aluminum oxide ceramic pinsere introduced for retrograde filling (215), but that system could note used in cases with limited working space or in teeth with large ovalanals. Since sonically or ultrasonically driven microsurgical retrotipsecame commercially available in the early 1990s (216 –219), this new

echnique of retrograde root canal instrumentation has been estab-ished as an essential adjunct in periradicular surgery (217, 220, 221).owever, the cutting properties of the retrotips at that time were limitednd seemed to be dependent on loading, power setting, and orientationf the tip to the long axis of the handpiece (222, 223). In some retrotips,ooling of the working tip was insufficient, and dentin and bone were atisk of being overheated (20).

The first root-end preparation using modified ultrasonic insertsollowing an apicoectomy is attributed to Bertrand et al. (224). Othersollowed, but it was not until 1987 that Flath and Hicks (225) furthereported on the use of ultrasonics and sonics for root-end cavity prep-ration.

Conventional root-end cavity preparation using rotary burs in aicrohandpiece is faced with several problems (21, 226, 227), such ascavity preparation not being parallel to the canal, difficult access to theoot end, and risk of lingual perforation of the root. Furthermore, thenability to prepare to a sufficient depth, thus compromising retention ofhe root-end filling material, means that the root-end resection proce-ure requires a longer cutting bevel, thus exposing more dentinal tu-ules and isthmus tissue, of which the latter is difficult to remove. Theevelopment of ultrasonic and sonic retrotips has revolutionized root-nd therapy, improving the surgical procedure with better access to theoot end, resulting in better canal preparation (226 –229). Ultrasonicetrotips come in a variety of shapes and angles, thus improving someteps during the surgical procedures (213, 230, 231) (Figs. 7 and 8).

At first glance, the most relevant clinical advantages are the en-anced access to root ends in a limited working space. This leads to amaller osteotomy for surgical access because of the advantage of usingarious angulations and the small size of the retrotips (232). However,number of studies compared root-end preparations made with mi-

rosurgical tips to those made with burs. They demonstrated additionaldvantages of this technique, such as deeper and more conservativeavities that follow the original path of the root canal more closely221, 233–237). A better-centered root-end preparation also lessenshe risk of lateral perforation (236 –238). Furthermore, the geometry

igure 8. Smooth stainless steel ultrasonic surgical retrotips.

f the retrotip design does not require a beveled root-end resection for


stTct

h2c

tipl

rooetatso((i2dtts

hrcrSe2mi

(dafbmcs(

mtec

aet2

R

tsc(e

phas3ma

taa1drsrp

ni

mvtwwtapcetqtm

Review Article

J

urgical access (232), thus decreasing the number of exposed dentinalubules (20, 239 –241) and minimizing apical leakage (242–245).hey also enable the removal of isthmus tissue present between twoanals within the same root (234, 236, 246 –248). It is considered aimesaving technique (234) that seems to have a lower failure rate (20).

The cleaning effect and the cutting ability of ultrasonic retrotipsave been described as satisfactory by many authors (222, 223, 233, 237,49, 250). Furthermore, US produced less smear layer in a retro-end cavityompared to a slow-speed handpiece (214, 221, 233–235, 251).

The refinement of cavity margins that were obtained with the ul-rasonic tips may positively affect the delivery of materials into the cav-ties and enhance their seal (214, 249, 252–254), even if cavities pre-ared with erbium:YAG lasers have been shown to produce significantlyower microleakage than ultrasonic preparations (255).

In a study by Walmsley et al. (256) the breakage of ultrasonicoot-end preparation tips was investigated and attributed to the designf the tip. Increased angulation of retrotips increases the transversescillation and decreases the longitudinal oscillation, putting the great-st strain at the bend of the instrument. The authors suggested reducinghe angulation and increasing the dimensions of the tip to resist break-ge. This may be true, but a straighter design will restrict access and ahicker instrument prevents instrumentation of isthmuses. A controver-ial issue with sonic or ultrasonic root-end preparation is the formationf cracks or microfractures and its implications for healing success257, 258). Some studies indicated that this was a possible drawback23, 238, 253, 259 –263). Other studies, however, disputed these find-ngs and did not report a higher prevalence of microfractures (19, 237,64 –272). Khabbaz et al. (237) found that cracks did not correlateirectly with the surface area of the root-end surfaces but rather with theype of retrotip used. Preparation with smooth stainless steel ultrasonicips produced fewer intradentin cracks than diamond-coated stainlessteel ultrasonic tips and sonic diamond-coated tips.

The influence of root-end microfractures on the periradicularealing process and apical leakage should be clarified (226). Apicalesorption after healing (273) may eliminate the surface defects andontribute to the overall success of treatment. Also, such defects can beemoved by finishing resected and retrofilled root-end surfaces (274).everal in vivo studies reported excellent success rates when the root-nd preparation was performed using ultrasonic retrotips (21, 212,75-283), thus demonstrating that modern surgical endodontic treat-ent using an operating microscope and ultrasonic tips significantly

mproves the outcome compared to the traditional techniques (284).It is recommended that the ultrasonic unit be set at medium power

267) and the cavities be prepared to a depth of 2.5-3 mm (285). Thisepth allows for a minimum thickness of material that can still providen effective apical seal (286). The cavity walls should be parallel andollow the anatomic outline of the pulpal space (230, 287). It has alsoeen suggested that root-end cavities should be initiated with a dia-ond-coated retrotip, using its better cutting ability to provide the main

avity. This aids in the removal of root canal obturation materials andhould be followed by a smooth retrotip to smooth and clean cavity walls248).

A condenser tip ultrasonically activated can be utilized for place-ent of retrograde filling materials, as the ultrasonic vibration is meant

o improve the flow, settling and compaction of these materials to root-nd dentinal walls. This should improve the delivery of materials into theavity thus enhancing their seal (210).

Ultrasonic tips can also be used to polish root end material andpical surfaces. Utilizing specific ultrasonic tips for refinement of thexternal radicular surface may be beneficial in the elimination of ex-raradicular bacteria, which may be responsible for infection (288,
89).

oot Canal PreparationUltrasonic devices were introduced for use in root canal prepara-

ion in 1957 by Richman (9). In 1980, Martin et al. (11, 12) demon-trated the ability of ultrasonically activated K-type files to cut dentin. Aommercial ultrasonic unit, designed by Cunningham and Martin147), was introduced in 1982. Barnett et al. (290, 291) and Tronstadt al. (292) were the first to report on its use in endodontics.

Several studies have shown that ultrasonically or sonically pre-ared teeth have significantly cleaner canals than teeth prepared byand instruments (14, 147–149, 293–296). Numerous studies havenalyzed the different characteristics of ultrasonically activated files,uch as cutting efficiency (11, 12, 297–302), effect on bacteria (168,03, 304), characteristics of root canal preparation (153, 305–313),echanical and technical features of files and handpieces (314 –318),

nd clinical implications (319 –323).The results of the above studies can be summarized as being con-

radictory. They failed to demonstrate the superiority of US or sonics asprimary instrumentation technique, as no improved debridement wasccomplished compared with hand instrumentation (22, 140, 152,60, 176, 194, 291, 324 –342). The relative inefficiency of ultrasonicebridement has been attributed to file constraint within the unflaredoot canal space (343). A modification of the technique in which ultra-ound is activated for a few minutes after hand preparation has insteadesulted in greater canal and isthmus cleanliness compared with handreparation alone (151, 177, 344 –346).

Despite the multitude of studies conducted on ultrasonic root ca-al preparation with ultrasonically activated files, the current consensus

s that this is not a viable clinical technique.

ConclusionsIt can be concluded from this review of the literature that US offers

any applications and advantages in clinical endodontics. Improvedisualization combined with a more conservative approach when selec-ively removing tooth structure, particularly in difficult situations inhich a specific angulation or tip design permits access to restrictedork areas, offers opportunities that are not possible with conventional

reatment. As a result, access refinement, location of calcified canals,nd removal of separated instruments or posts have generated moreredictable results. In addition, better action of irrigation solutions andondensation of gutta-percha have benefited from the use of US. Root-nd cavity preparation followed by placement of materials in an areahat is more often than not constrained has especially improved theuality of treatment and long-term success. Finally, integration of new

echnologies such as US, leading to improved techniques and use ofaterials, has changed the way endodontics is being practiced today.

References1. Catuna MC. Ultrasonic energy: a possible dental application. Preliminary report of

an ultrasonic cutting method. Ann Dent 1953;12:256 – 60.2. Postle HH. Ultrasonic cavity preparation. J Prosthet Dent 1958;8:153– 60.3. Balamuth L. The application of ultrasonic energy in the dental field. In: Brown B,

Gordon D, eds. Ultrasonic techniques in biology and medicine. London: Ilife;1967:194 –205.

4. Oman CR, Applebaum E. Ultrasonic cavity preparation II. Progress report. J AmDent Assoc 1954;50:414 –7.

5. Nielsen AG, Richards JR, Wolcott RB. Ultrasonic dental cutting instrument: I. J AmDent Assoc 1955;50:392–9.

6. Street EV. Critical evaluation of ultrasonics in dentistry. J Prosthet Dent1959;9:32– 41.

7. Zinner DD. Recent ultrasonic dental studies including periodontia, without the useof an abrasive. J Dent Res 1955;34:748 –9.

8. Johnson WN, Wilson JR. Application of the ultrasonic dental unit to scaling proce-
dures. J Periodontol 1957;28:264 –71.

Review Article

9

9. Richman RJ. The use of ultrasonics in root canal therapy and root resection. MedDent J 1957;12:12– 8.

10. Martin H. Ultrasonic disinfection of the root canal. Oral Surg Oral Med Oral Pathol1976;42:92–9.

11. Martin H, Cunningham WT, Norris JP, Cotton WR. Ultrasonic versus hand filing ofdentin: a quantitative study. Oral Surg Oral Med Oral Pathol 1980;49:79 – 81.

12. Martin H, Cunningham WT, Norris JP. A quantitative comparison of the ability ofdiamond and K-type files to remove dentin. Oral Surg Oral Med Oral Pathol1980;50:566 – 8.

13. Martin H, Cunningham W. Endosonic endodontics: the ultrasonic synergistic sys-tem. Int Dent J 1984;34:198 –203.

14. Martin H, Cunningham W. Endosonics: the ultrasonic synergistic system of end-odontics. Endod Dent Traumatol 1985;1:201– 6.

15. Stock CJR. Current status of the use of ultrasound in endodontics. Int Dent J1991;41:175– 82.

16. Laurichesse JM. La technique de l’appui parietal (T.A.P.) Rev Franc Endod1985;4:19 –38.

17. Ahmad M, Roy RA, Kamarudin AG, Safar M. The vibratory pattern of ultrasonic filesdriven piezoelectrically. Int Endod J 1993;26:120 – 4.

18. Lumley PJ, Walmsley AD, Marquis PM. Effect of air inlet ring opening on sonichandpiece performance. J Dent 1994;22:376 –9.

19. Lloyd A, Jatmberzins A, Dummer PM, Bryant S. Root-end cavity preparation usingthe Micro Mega Sonic Retro-prep tip: SEM analysis. Int Endod J 1996;29:295–301.

20. von Arx T, Kurt B, Ilgenstein B, Hardt N. Preliminary results and analysis of a new setof sonic instruments for root-end cavity preparation. Int Endod J 1998;31:32– 8.

21. von Arx T, Kurt B. Root-end cavity preparation after apicoectomy using a new typeof sonic and diamond-surfaced retrotip: a 1-year follow-up study. J Oral MaxillofacSurg 1999;57:656 – 61.

22. Ahmad M, Pitt Ford TR, Crum LA. Ultrasonic debridement of root canals: an insightinto the mechanisms involved. J Endod 1987;13:93–101.

23. Layton CA, Marshall JG, Morgan LA, Baumgartner JC. Evaluation of cracks associ-ated with ultrasonic root-end preparation. J Endod 1996;22:157– 60.

24. Walmsley AD. Ultrasound and root canal treatment: the need for scientific evalua-tion. Int Endod J 1987;20:105–11.

25. Lumley PJ, Walmsley AD, Laird WRE. An investigation into the occurrence of cavi-tational activity during endosonic instrumentation. J Dent 1988;16:120 –2.

26. Laird WRE, Walmsley AD. Ultrasound in dentistry: Part 1. Biophysical interactions.J Dent 1991;19:14 –7.

27. Lea SC, Walmsley AD, Lumley PJ, Landini G. A new insight into the oscillationcharacteristics of endosonic files used in dentistry. Phys Med Biol 2004;49:2095–102.

28. Walmsley AD. Applications of ultrasound in dentistry. Ultrasound Med Biol1988;14:7–14.

29. Walmsley AD, Laird WRE, Lumley PJ. Ultrasound in dentistry: Part 2. Periodontologyand endodontics. J Dent 1992;20:11–7.

30. Peters MC, McLean ME. Minimally invasive operative care. I. Minimal interventionand concepts for minimally invasive cavity preparations. J Adhes Dent 2001;3:7–16.

31. Peters MC, McLean ME. Minimally invasive operative care. II. Contemporary tech-niques and materials: an overview. J Adhes Dent 2001;3:17–31.

32. Sheets CG, Paquette JM. Ultrasonic tips for conservative restorative dentistry. DentToday 2002;21:102– 4.

33. Clark D. The operating microscope and ultrasonics: a perfect marriage. Dent Today2004;23:74 – 81.

34. Buchanan LS. Innovations in endodontics instruments and techniques: how theysimplify treatment. Dent Today 2002;21:52– 61.

35. Sempira HN, Hartwell GR. Frequency of second mesiobuccal canals in maxillarymolars as determined by use of an operating microscope: a clinical study. J Endod2000;26:673– 4.

36. Gorduysus MO, Gorduysus M, Friedman S. Operating microscope improves nego-tiation of second mesiobuccal canals in maxillary molars. J Endod 2001;27:683– 6.

37. Rampado ME, Tjaderhane L, Friedman S, Hamstra SJ. The benefit of the operatingmicroscope for access cavity preparation by undergraduate students. J Endod2004;30:863–7.

38. Lin YH, Mickel AK, Jones JJ, Montagnese TA, Gonzalez AF. Evaluation of cuttingefficiency of ultrasonic tips used in orthograde endodontic treatment. J Endod2006;32:359 – 61.

39. Paz E, Satovsky J, Moldauer I. Comparison of the cutting efficiency of two ultrasonicunits utilizing two different tips at two different power settings. J Endod 2005;31:824 – 6.

40. Waplington M, Lumley PJ, Bunt L. An in vitro investigation into the cutting action ofultrasonic radicular access preparation instruments. Endod Dent Traumatol2000;16:158 – 61.

41. Ruddle CJ. Nonsurgical endodontic retreatment. J Calif Dent Assoc 2004;32:
474 – 84.
0 Plotino et al.

42. Johnson WB, Beatty RG. Clinical technique for the removal of the root canal ob-structions. J Am Dent Assoc 1988;117:473– 6.

43. Hulsmann M. Methods for removing metal obstructions from the root canal. EndodDent Traumatol 1993;9:223–37.

44. Fors UGH, Berg JO. Endodontic treatment of root canals obstructed by foreignobjects. Int Endod J 1986;19:2–10.

45. Weisman MI. The removal of difficult silver cones. J Endod 1983;9:210 –1.46. Meidinger DL, Kabes BJ. Foreign object removal utilizing the Cavi-Endo ultrasonic

instrument. J Endod 1985;11:301– 4.47. Glick DH, Frank AL. Removal of silver points and fractured posts by ultrasonics.

J Prosthet Dent 1986;55:212–5.48. Chenail BL, Teplitsky PE. Orthograde ultrasonic retrivial of root canal obstructions.

J Endod 1987;13:186 –90.49. Stamos DE, Stamos DG, Perkins SK. Retreatodontics and ultrasonics. J Endod

1988;14:39 – 42.50. Hulsmann M. The removal of silver cones using different techniques. Int Endod J

1990;23:298 –303.51. Sprigs K, Gettleman B, Messer H. Evaluation of a new method for silver points

removal. J Endod 1990;16:335– 8.52. Masserann J. The extraction of posts broken deeply in the roots. Actual Odontos-

tomatol 1986;75:392– 402.53. Gettleman BH, Spriggs KA, Messer HH, El Deeb ME. Removal of canal obstructions

with the Endo Extractor. J Endod 1991;17:608 –11.54. Roig-Greene JL. The retrieval of foreign objects from root canals: a simple aid.

J Endod 1983;9:394 –7.55. Gaffney JL, Lehman JW, Miles MJ. Expanded use of the ultrasonic scaler. J Endod

1981;5:228 –9.56. Souyave LC, Inglis AT, Alcalay M. Removal of fractured instruments using ultrason-

ics. Br Dent J 1985;159:251–3.57. Nagai O, Tani N, Kayaba Y, Kodama S, Osada T. Ultrasonic removal of broken

instruments in root canals. Int Endod J 1986;19:298 –304.58. Grossman LI. Fate of endodontically treated teeth with fractured root canal instru-

ments. J Br Endod Soc 1968;2:35–7.59. Crump MC, Natkin E. Relationship of broken root canal instruments to endodontic

case prognosis: a clinical investigation. J Am Dent Assoc 1970;80:1341–7.60. Hulsmann M. Removal of fractured instruments using a combined automated/

ultrasonic technique. J Endod 1994;20:144 –7.61. Hulsmann M, Schinkel I. Influence of several factors on the success or failure of

removal of fractured instruments from the root canal. Endod Dent Traumatol1999;15:252– 8.

62. Nehme WB. Elimination of intracanal metallic obstructions by abrasion using anoperational microscope and ultrasonics. J Endod 2001;27:365–7.

63. Ward JR, Parashos P, Messer HH. Evaluation of an ultrasonic technique to removefractured rotary nickel-titanium endodontic instruments from root canals: clinicalcases. J Endod 2003;29:764 –7.

64. Ruddle CJ. Nonsurgical retreatment. In: Cohen S, Burns RC, eds. Pathways of thepulp, 8th ed. St Louis: Mosby; 2002:875–930.

65. Ward JR, Parashos P, Messer HH. Evaluation of an ultrasonic technique to removefractured rotary nickel-titanium endodontic instruments from root canals: an ex-perimental study. J Endod 2003;29:756 – 63.

66. Hulsmann M. Removal of silver cones and fractured instruments using the canalfinder system. J Endod 1990;16:596 – 600.

67. Feldman G, Solomon C, Notaro P, Moskovitz E. Retrieving broken endodontic in-struments. J Am Dent Assoc 1974;88:588 –91.

68. Shen Y, Peng B, Cheung GS. Factors associated with the removal of fractured NiTiinstruments from root canal systems. Oral Surg Oral Med Oral Pathol Oral RadiolEndod 2004;98:605–10.

69. Souter NJ, Messer HH. Complications associated with fractured file removal usingan ultrasonic technique. J Endod 2005;31:450 –2.

70. Gilbert BOI, Rice T. Re-treatment in endodontics. Oral Surg Oral Med Oral Pathol1987;64:333– 8.

71. Ruddle CJ. Micro-endodontic non-surgical retreatment. Dent Clin North Am1997;41:429 –54.

72. D’Arcangelo C, Varvara G, De Fazio P. Broken instrument removal-two cases.J Endod 2000;26:368 –70.

73. Ward JR. The use of an ultrasonic technique to remove a fractured rotary nickel-titanium instrument from the apical third of a curved root canal. Aust Dent J2003;29:25–30.

74. Wu MK, van der Sluis LW, Wesselink PR. The risk of furcal perforation in mandib-ular molars using Gates-Glidden drills with anticurvature pressure. Oral Surg OralMed Oral Pathol Oral Radiol Endod 2005;99:378 – 82.

75. Zuckerman O, Katz A, Pilo R, Tamse A, Fuss Z. Residual dentin thickness in mesialroots of mandibular molars prepared with Lightspeed rotary instruments and Gates-Glidden reamers. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003;
96:351–5.

1

1

1

11

1

11

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

11

1

1

1

1

1

1

1

1

1

1

1

Review Article

J

76. Kuttler S, McLean A, Dorn S, Fischzang A. The impact of post space preparation withGates-Glidden drills on residual dentin thickness in distal roots of mandibularmolars. J Am Dent Assoc 2004;135:903–9.

77. Tilk MA, Lommel TJ, Gerstein H. A study of mandibular and maxillary root widths todetermine dowel size. J Endod 1979;5:79 – 82.

78. Pilo R, Tamse A. Residual dentin thickness in mandibular premolars prepared withGates Glidden and ParaPost drills. J Prosthet Dent 2000;83:617–23.

79. Pilo R, Corcino G, Tamse A. Residual dentin thickness in mandibular premolarsprepared with hand and rotatory instruments. J Endod 1998;24:401– 4.

80. Tamse A, Katz A, Pilo R. Furcation groove of buccal root of maxillary first premolars:a morphometric study. J Endod 2000;26:359 – 63.

81. Raiden G, Costa L, Koss S, Hernandez JL, Acenolaza V. Residual thickness of root infirst maxillary premolars with post space preparation. J Endod 1999;25:502–5.

82. Katz A, Wasenstein-Kohn S, Tamse A, Zuckerman O. Residual dentin thickness inbifurcated maxillary premolars after root canal and dowel space preparation.J Endod 2006;32:202–5.

83. Raiden G, Koss S, Costa L, Hernandez JL. Radiographic measurement of residualroot thickness in premolars with post preparation. J Endod 2001;27:296 – 8.

84. Iqbal MK, Rafailov H, Kratchman SI, Karabucak B. A comparison of three methodsfor preparing centered platforms around separated instruments in curved canals.J Endod 2006;32:48 –51.

85. Stamos DE, Gutmann JL. Survey of endodontic retreatment methods used to removeintraradicular posts. J Endod 1993;19:366 –9.

86. Berbert A, Filho MT, Ueno AH, Bramante CM, Ishikiriama A. The influence ofultrasound in removing intraradicular posts. Int Endod J 1995;28:54 – 6.

87. Berbert A, Filho MT, Ueno AH, Bramante CM, Ishikiriama A. The influence ofultrasound in removing intraradicular posts. Int Endod J 1995;28:100 –2.

88. Altshul JH, Marshall G, Morgan LA, Baumgartner JC. Comparison of dentinal crackincidence and of post removal time resulting from post removal by ultrasonic ormechanical force. J Endod 1997;23:683– 6.

89. Williams VD, Bjorndal AM. The Masserann technique for the removal of fracturedposts in endodontically treated teeth. J Prosthet Dent 1983;49:46 – 8.

90. Bando E, Kawashima T, Tiu IT, Kubo Y, Nakano M. Removing dowels in difficultteeth. J Prosthet Dent 1985;54:34 – 6.

91. Shemen BB, Cardash HS. A technique for removing posts. J Prosthet Dent1985;54:200 –1.

92. Cheuk SL, Karam PE. Removal of parallel prefabricated posts: a clinical report.J Prosthet Dent 1988;59:531–3.

93. Machtou P, Sarfati P, Cohen AG. Post removal prior to retreatment. J Endod1989;15:552– 4.

94. Parreira FR, O’Connor RP, Hutter JW. Cast prosthesis removal using ultrasonicsand a thermoplastic resin adhesive. J Endod 1994;20:141–3.

95. Krell KV, Jordan RD, Madison S, Aquilino S. Using ultrasonic scalers to removefractured posts. J Prosthet Dent 1986;55:46 –9.

96. Castrisos T, Abbott PV. A survey of methods used for post removal in specialistendodontic practice. Int Endod J 2002;35:172– 80.

97. Hauman CHJ, Chandler NP, Purton DG. Factors influencing the removal of posts. IntEndod J 2003;36:687–90.

98. Ruddle CJ. Nonsurgical retreatment. J Endod 2004;30:827– 45.99. De Rijk WG Removal of fiber posts from endodontically treated teeth. Am J Dent

2000;13:19B–21B.00. Gesi A, Magnolfi S, Goracci C, Ferrari M. Comparison of two techniques for remov-

ing fiber posts. J Endod 2003;29:580 –2.01. Lindemann M, Yaman P, Dennison JB, Herrero AA. Comparison of the efficiency and

effectiveness of various techniques for removal of fiber posts. J Endod 2005;31:520 –2.

02. Buoncristiani J, Seto BG, Caputo AA. Evaluation of ultrasonic and sonic instrumentsfor intraradicular post removal. J Endod 1994;20:486 –9.

03. Jaeger JC. Elasticity, fracture and flow, 1st ed. London: Methuen; 1962: 133.04. O’Brien J. Dental Materials, properties and selections, 1st ed. Chicago: Quintes-

sence; 1989: 549 –51.05. Lassila LVJ, Tanner J, Le Bell A-M, Narva K, Vallittu P. Flexural properties of fiber

reinforced root canal posts. Dent Mater 2004;20:29 –36.06. Phillips RW. Skinner’s science of dental materials.Philadephia: Saunders; 1996.07. Garrido AD, Fonseca TS, Alfredo E, Silva-Sousa YT, Sousa-Neto MD. Influence of

ultrasound, with and without water spray cooling, on removal of posts cementedwith resin or zinc phosphate cements. J Endod 2004;30:173– 6.

08. Watanabe EK, Yatani H, Yamashita A, Ishikawa K, Suzuki K. Effects of thermocyclingon the tensile bond strength between resin cement and dentin surfaces after tem-porary cement application. Int J Prosthodont 1999;12:230 –5.

09. Johnson WT, Leary JM, Boyer DB. Effect of ultrasonic vibration on post removal inextracted human premolar teeth. J Endod 1996;22:487– 8.

10. Yoshida T, Shunji G, Tomomi I, Shibata T, Sekine I. An experimental study of theremoval of cemented dowel-retained cast cores by ultrasonic vibration. J Endod
1997;23:239 – 41.

11. Gomes APM, Kubo CH, Santos DR, Padilha RQ. The influence of ultrasound on theretention of cast posts cemented with different agents. Int Endod J 2001;34:93–9.

12. Smith BJ. Removal of fractured posts using ultrasonic vibration: an in vivo study.J Endod 2001;27:632– 4.

13. Dixon EB, Kaczkowski PJ, Nicholls JI, Harrington GW. Comparison of two ultrasonicinstruments for post removal. J Endod 2002;28:111–5.

14. Alfredo E, Garrido AD, Souza-Filho CB, Correr-Sobrinho L, Sousa-Neto MD. In vitroevaluation of the effect of core diameter for removing radicular post with ultra-sound. J Oral Rehabil 2004;31:590 – 4.

15. Silva MR, Biffi JC, Mota AS, Fernandes Neto AJ, Neves FD. Evaluation of intracanalpost removal using ultrasound. Braz Dent J 2004;15:119 –26.

16. Braga NM, Alfredo E, Vansan LP, Fonseca TS, Ferraz JA, Sousa-Neto MD. Efficacy ofultrasound in removal of intraradicular posts using different techniques. J Oral Sci2005;47:117–21.

17. Chandler NP, Qualtrough AJE, Purton DG. Comparison of two methods for removalof root canal posts. Quintessence Int 2003;34:534 – 6.

18. Ruddle CJ. Nonsurgical endodontic retreatment. J Calif Dent Assoc 1997;25:769 – 86.

19. Bergeron BE, Murchison DF, Schindler DF, Walker WA III. Effect of ultrasonicvibration and various sealer and cement combinations on titanium post removal.J Endod 2001;27:13–7.

20. Budd JC, Gekelman D, White JM. Temperature rise of the post and on the rootsurface during ultrasonic post removal. Int Endod J 2005;38:705–11.

21. Gluskin AH, Ruddle CJ, Zinman EJ. Thermal injury through intraradicular heattransfer using ultrasonic devices: precautions and practical preventive strategies.J Am Dent Assoc 2005;136:1286 –93.

22. Dominici JT, Clark S, Scheetz J, Eleazer PD. Analysis of heat generation using ultra-sonic vibration for post removal. J Endod 2005;31:301–3.

23. Satterthwaite JD, Stokes AN, Frankel NT. Potential for temperature change duringapplication of ultrasonic vibration to intra-radicular posts. Eur J Prosthodont RestorDent 2003;11:51– 6.

24. Sieraski SM, Zillich RM. Silver point retreatment: review and case report. J Endod1983;9:35–9.

25. Suter B. A new method for retrieving silver points and separated instruments fromroot canals. J Endod 1998;24:446 – 8.

26. Nehme W. A new approach for the retrieval of broken instruments. J Endod1999;25:633–5.

27. Cherukara GP, Pollock GR, Wright PS. Case report: removal of fractured endodonticposts with a sonic instrument. Eur J Prosthodont Restor Dent 2002;10:23– 6.

28. Abou-Rass M, Piccinino MV. The effectiveness of four clinical irrigation methods onthe removal of root canal debris. Oral Surg Oral Med Oral Pathol 1982;54:323– 8.

29. Lee SJ, Wu MK, Wesselink PR. The effectiveness of syringe irrigation and ultrasonicsto remove debris from simulated irregularities within prepared root canal walls. IntEndod J 2004;37:672– 8.

30. Baker NA, Eleazer PD, Averbach RE. Scanning electron microscopic study of theefficacy of various irrigation solutions. J Endod 1975;1:127–35.

31. Chow TW. Mechanical effectiveness of root canal irrigation. J Endod 1983;9:475–9.32. Teplitsky PE, Chenail BL, Mack B, Machnee CH. Endodontic irrigation: a compari-

son of endosonic and syringe delivery systems. Int Endod J 1987;20:233– 41.33. Ram Z. Effectiveness of root canal irrigation. Oral Surg Oral Med Oral Pathol

1977;44:306 –12.34. Walters MJ, Baumgartner JC, Marshall JG. Efficacy of irrigation with rotary instru-

mentation. J Endod 2002;28:837–9.35. van der Sluis LW, Gambarini G, Wu MK, Wesselink PR. The influence of volume, type

of irrigant and flushing method on removing artificially placed dentine debris fromthe apical root canal during passive ultrasonic irrigation. Int Endod J 2006;39:472– 6.

36. Wu MK, Wesselink PR. Efficacy of three techniques cleaning the apical portion ofcurved root canals. Oral Surg Oral Med Oral Pathol 1995;79:492– 6.

37. Baumgartner JC, Cuenin PR. Efficacy of several concentrations of sodium hypochlo-rite for root canal irrigation. J Endod 1992;18:605–12.

38. Gutarts R, Nusstein J, Reader A, Beck M. In vivo debridement efficacy of ultrasonicirrigation following hand-rotary instrumentation in human mandibular molars.J Endod 2005;31:166 –70.

39. Griffiths BM, Stock CJR. The efficiency of irrigants in removing root canal debriswhen used with an ultrasonic preparation technique. Int Endod J 1986;19:277– 84.

40. Ahmad M, Pitt Ford TR, Crum LA. Ultrasonic debridement of root canals: acousticstreaming and its possible role. J Endod 1987;13:490 –9.

41. Krell KV, Johnson RJ. Irrigation patterns during ultrasonic canal instrumentation.Part II. Diamond-coated files. J Endod 1988;14:535–7.

42. Krell KV, Johnson RJ, Madison S. Irrigation pattern during ultrasonic canal instru-mentation. Part I. K-type files. J Endod 1988;14:65– 8.

43. Jensen SA, Walker TL, Hutter JW, Nicoll BK. Comparison of cleaning efficacy ofpassive sonic activation and passive ultrasonic activation after hand instrumentation
in molar root canals. J Endod 1999;25:735– 8.

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

11

1

1

1

1

1

11

1

1

1

1

1

1

1

2

2

2

2

2

2

Review Article

9

44. Druttman ACS, Stock CJR. An in vitro comparison of ultrasonic and conventionalmethods of irrigant replacement. Int Endod J 1989;22:174 – 8.

45. Cheung GS, Stock CJ. In vitro cleaning ability of root canal irrigants with and withoutendosonics. Int Endod J 1993;26:334 – 43.

46. Weller RN, Brady JM, Bernier WE. Efficacy of ultrasonic cleaning. J Endod1980;6:740 –3.

47. Cunningham WT, Martin H. A scanning electron microscope evaluation of root canaldebridement with the endosonic ultrasonic synergistic system. Oral Surg Oral MedOral Pathol 1982;53:527–31.

48. Cunningham WT, Martin H, Forrest WR. Evaluation of root canal debridement by theendosonic ultrasonic synergistic system. Oral Surg Oral Med Oral Pathol 1982;53:401– 4.

49. Cunningham WT, Martin H, Pelleu GB, Stoops DE. A comparison of antimicrobialeffectiveness of endosonic and hand root canal therapy. Oral Surg Oral Med OralPathol 1982;54:238 – 41.

50. Giangrego E. Changing concepts in endodontic therapy. J Am Dent Assoc1985;110:470 – 8.

51. Goodman A, Beck M, Melfi R, Meyers W. An in vitro comparison of the efficacy of thestep-back technique versus a step-back/ultrasonic technique in human mandibularmolars. J Endod 1985;11:249 –56.

52. Stamos DE, Sadeghi EM, Haasch GC, Gerstein H. An in vitro comparison study toquantitate the debridement ability of hand, sonic, and ultrasonic instrumentation.J Endod 1987;13:434 – 40.

53. Lumley PJ, Walmsley AD, Walton RE, Rippin JW. Cleaning of oval canals usingultrasonic or sonic instrumentation. J Endod 1993;19:453–7.

54. Cameron JA. The choice of irrigant during hand instrumentation and ultrasonicirrigation of the root canal: a scanning electron microscope study. Aust Dent J1995;40:85–90.

55. Cameron JA. Factors affecting the clinical efficiency of ultrasonic endodontics: ascanning electron microscopy study. Int Endod J 1995;28:47–53.

56. Ardila CN, Wu M-K, Wesselink PR. Percentage of filled canal area in mandibularmolars after conventional root canal instrumentation and after a noninstrumenta-tion technique (NIT). Int Endod J 2003;36:591– 8.

57. Sabins RA, Johnson JD, Hellstein JW. A comparison of the cleaning efficacy ofshort-term sonic and ultrasonic passive irrigation after hand instrumentation inmolar root canals. J Endod 2003;29:674 – 8.

58. Ferreira RB, Alfredo E, Porto de Arruda M, Silva Sousa YT, Sousa-Neto MD. Histo-logical analysis of the cleaning capacity of nickel-titanium rotary instrumentationwith ultrasonic irrigation in root canals. Aust Endod J 2004;30:56 – 8.

59. Moorer WR, Wesselink PR. Factors promoting the tissue dissolving capability ofsodium hypochlorite. Int Endod J 1982;15:187–96.

60. Ahmad M, Pitt Ford TR, Crum LA, Walton AJ. Ultrasonic debridement of root canals:acoustic cavitation and its relevance. J Endod 1988;14:486 –93.

61. Lee SJ, Wu MK, Wesselink PR. The effectiveness of ultrasonic irrigation to removeartificially placed dentine debris from different-sized simulated plastic root canals.Int Endod J 2004;37:607–12.

62. Sjogren U, Sunqvist G. Bacteriologic evaluation of ultrasonic root canal instrumen-tation. Oral Surg Oral Med Oral Pathol 1987;63:366 –70.

63. Abbot PV, Heijkoop PS, Cardaci SC, Hume WR, Heithersay GS. An SEM study of theeffects of different irrigation sequences and ultrasonics. Int Endod J 1991;24:308 –16.

64. Briseno BM, Wirth R, Hamm G, Standhartinger W. Efficacy of different irrigationmethods and concentrations of root canal irrigation solutions on bacteria in theroot canal. Endod Dent Traumatol 1992;8:6 –11.

65. Huque J, Kota K, Yamaga M, Iwaku M, Hoshino E. Bacterial eradication from rootdentine by ultrasonic irrigation with sodium hypochlorite. Int Endod J 1998;31:242–50.

66. Mayer BE, Peters OA, Barbakow F. Effects of rotary instruments and ultrasonicirrigation on debris and smear layer scores: a scanning electron microscopic study.Int Endod J 2002;35:582–9.

67. Ahmad M. Effect of ultrasonic instrumentation on Bacteroides intermedium.Endod Dent Traumatol 1989;5:83– 6.

68. Williams AR. Disorganization and disruption mammalian and ameboid cells byacoustic streaming. J Acoust Soc Am 1972;52:688 –93.

69. Spoleti P, Siragusa M, Spoleti MJ. Bacteriological evaluation of passive ultrasonicactivation. J Endod 2003;29:12– 4.

70. Bystrom A, Sundqvist G. Bacteriologic evaluation of the efficacy of mechanical rootcanal instrumentation in endodontic therapy. Scand J Dent Res 1981,89:321– 8.

71. Cameron JA. The synergistic relationship between ultrasound and sodium hypo-chlorite: a scanning electron microscope evaluation. J Endod 1987;13:541–5.

72. Cunningham WT, Balekjian BA. The effect of temperature on the collagen dissolvingability of sodium hypochlorite as an endodontic irrigant. Oral Surg Oral Med OralPathol 1980;49:175–7.

73. Ahmad M. Measurements of temperature generated by ultrasonic file in vitro. Endod
Dent Traumatol 1990;6:230 –1.
2 Plotino et al.

74. Senia ES, Marshall FJ, Rosen J. The solvent action of sodium hypochlorite on pulptissue of extracted teeth. Oral Surg Oral Med Oral Pathol 1971;31:96 –103.

75. McComb D, Smith DC, Beagrie GS. The results of in vivo endodontic chemome-chanical instrumentation: a scanning electron microscopic study. J Br Endod Soc1976;9:11– 8.

76. Langeland K, Liao K, Pascon EA. Work-saving devices in endodontics: efficacy ofsonic and ultrasonic techniques. J Endod 1985;11:499 –510.

77. Lev R, Reader A, Beck M, Meyers W. An in vitro comparison of the step-backtechnique versus a step-back ultrasonic technique for 1 and 3 minutes. J Endod1987;13:523–9.

78. Heard F, Walton RE. Scanning electron microscope study comparing four root canalpreparation techniques in small curved canals. Int Endod J 1997;30:323–31.

79. Usman N, Baumgartner JC, Marshall JG. Influence of instrument size on root canaldebridement. J Endod 2004;30:110 –2.

80. Walmsley AD, Williams AR. Effects of constraint on the oscillatory pattern of end-odontic files. J Endod 1989;15:189 –94.

81. Guerisoli DMZ, Marchesan MA, Walmsley AD, Lumley PJ, Pecora JD. Evaluation ofsmear layer removal by EDTAC and sodium hypochlorite with ultrasonic agitation.Int Endod J 2002;35:418 – 421.

82. Karadag LS, Tinaz AC, Mihcioglu T. Influence of passive ultrasonic activation on thepenetration depth of different sealers. J Contemp Dent Pract 2004;517.

83. van der Sluis LW, Wu MK, Wesselink PR. The efficacy of ultrasonic irrigation toremove artificially placed dentine debris from human root canals prepared usinginstruments of varying taper. Int Endod J 2005;38:764 – 8.

84. Zehnder M. Root canal irrigants. J Endod 2006;32:389 –98.85. Roy RA, Ahmad M, Crum LA. Physical mechanisms governing the hydrodynamic

response of an oscillating ultrasonic file. Int Endod J 1994;27:197–207.86. Cymerman J, Jerome L, Moodnik R. A scanning electron microscope study

comparing the efficacy of hand instrumentation with ultrasonic instrumentationof the root canal. J Endod 1983;9:327–31.

87. Cameron JA. The use of ultrasonics in the removal of the smear layer: a scanningelectron microscope study. J Endod 1983;9:289 –92.

88. Cameron JA. The use of ultrasound and an EDTA– urea peroxide compound in thecleansing of root canals: an SEM study. Aust Dent J 1984;29:80 –5.

89. Ciucchi B, Khettabi M, Holz J. The effectiveness of different endodontic irrigationprocedures on the removal of the smear layer: a scanning electron microscopicstudy. Int Endod J 1989;22:21– 8.

90. Cameron JA. The use of ultrasound in the cleaning of root canals: a clinical report.J Endod 1982;8:471–3.

91. Crabb HSM. The cleansing of root canals. Int Endod J 1982;15:62– 6.92. Cameron JA. The use of ultrasound for the removal of the smear layer. The effect of

sodium hypochlorite concentrations: SEM study. Aust Dent J 1988;33:193–200.93. Tauber R, Morse DR, Sinai IA, Furst ML. A magnifying lens comparative evaluation

of conventional and ultrasonically energized filing. J Endod 1983;9:269 –74.94. Goldman M, White RR, Moser CR, Tenca JI. A comparison of three methods of

cleaning and shaping the root canal in vitro. J Endod 1988;14:7–12.95. Sundqvist G, Figdor D. Endodontic treatment of apical periodontitis. In: Ørstavik D,

Pitt Ford TR, eds. Essential endodontology, 2nd ed. Oxford, UK: Blackwell Science,1998:242–270.

96. van der Sluis LW, Wu MK, Wesselink PR. A comparison between a smooth wire anda K-file in removing artificially placed dentine debris from root canals in resinblocks during ultrasonic irrigation. Int Endod J 2005;38:593– 6.

97. Serafino C, Gallina G, Cumbo E, Ponticelli F, Goracci C, Ferrari M. Ultrasound effectsafter post space preparation: an SEM study. J Endod 2006;32:549 –52.

98. Moreno A. Thermomechanical softened gutta-percha root canal filling. J Endod1977;3:186 – 8.

99. Joiner HL, Canales ML, Del Rio CE. Temperature changes in thermoplasticizedgutta-percha: a comparison of two ultrasonic units. Oral Surg Oral Med Oral Pathol1989;68:764 –9.

00. Baumgardner KR, Krell KV. Ultrasonic condensation of gutta-percha: an in vitro dyepenetration and scanning electron microscope study. J Endod 1990;16:253–9.

01. Deitch AK, Liewehr FR, West LA, William R. Patton WR. A comparison of fill densityobtained by supplementing cold lateral condensation with ultrasonic condensation.J Endod 2002;28:665–7.

02. Zmener O, Banegas G. Clinical experience of root canal filling by ultrasonic con-densation of gutta-percha. Endod Dent Traumatol 1999;15:57–9.

03. Amditis C, Blackler SM, Bryant RW, Hewitt GH. The adaptation achieved by four rootcanal filling techniques as assessed by three methods. Aust Dent J 1992;37:439 – 44.

04. Bailey GC, Cunnington SA, Ng Y-L, Gulabivala K, Setchell DJ. Ultrasonic condensationof gutta-percha: the effect of power setting and activation time on temperature riseat the root surface—an in vitro study. Int Endod J 2004;37:447–54.

05. Bailey GC, Ng Y-L, Cunnington SA, Barber P, Gulabivala K, Setchell DJ. Root canalobturation by ultrasonic condensation of gutta-percha. Part II: An in vitro investi-
gation of the quality of obturation. Int Endod J 2004;37:694 – 8.

2

2

2

2

2

2

2

2

2

2

2

2

2

22

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

Review Article

J

06. Schilder H, Goodman A, Aldrich W. The thermomechanical properties of gutta-percha.Part V. Volume changes in bulk gutta-percha as a function of temperatureand its relationship to molecular phase transformation. Oral Surg Oral Med OralPathol 1985;58:285–96.

07. West LA, LaBounty GL, Keller DL. Obturation quality utilizing ultrasonic cleaning andsealer placement followed by lateral condensation with gutta-percha. J Endod1989;15:507–11.

08. Stamos DE, Gutmann JL, Gettleman BH. In vivo evaluation of root canal sealerdistribution. J Endod 1995;21:177–9.

09. Witherspoon D, Ham K. One-visit apexification: technique for inducing root-endbarrier formation in apical closures. Pract Proced Aesthet Dent 2001;13:455– 60.

10. Lawley GR, Schindler WG, Walker WA, Kolodrubetz D. Evaluation of ultrasonicallyplaced MTA and fracture resistance with intracanal composite resin in a model ofapexification. J Endod 2004;30:167–72.

11. Aminoshariae A, Hartwell GR, Moon PC. Placement of mineral trioxide aggregateusing two different techniques. J Endod 2003;29:679 – 82.

12. Sumi Y, Hattori H, Hayashi K, Ueda M. Ultrasonic root-end preparation: clinical andradiographic evaluation of results. J Oral Maxillofac Surg 1996;54:590 –3.

13. Carr G. Surgical endodontics. In: Cohen S, Burns R, eds. Pathways of the pulp, 4thed. St. Louis: Mosby; 1994:546 –552.

14. Sutimuntanakul S, Worayoskowit W, Mangkornkarn C. Retrograde seal in ultrason-ically prepared canals. J Endod 2000;26:444 – 6.

15. Keller U. Aluminium oxide ceramic pins for retrograde root filling: experiences witha new system. Oral Surg Oral Med Oral Pathol 1990;69:737– 42.

16. Pannkuk TF. Endodontic surgery: principles, objectives and treatment of posteriorteeth: Part I. Endod Rep 1991;6:8 –14.

17. Carr G. Advanced techniques and visual enhancement for endodontic surgery.Endod Rep 1992;7:6.9.

18. Pannkuk TF. Endodontic surgery: the treatment phase and wound healing: Part II.Endod Rep 1992;7:14 –9.

19. Fong CD. A sonic instrument for retrograde preparation. J Endod 1993;19:374 –5.20. Gutmann JL, Pitt Ford TR. Management of the resected root-end: a clinical review.

Int Endod J 1993;26:273– 83.21. Wuchenich G, Meadows D, Torabinejad M. A comparison between two root end

preparation techniques in human cadavers. J Endod 1994;20:279 – 82.22. Waplington M, Lumley PJ, Walmsley AD, Blunt L. Cutting ability of an ultrasonic

retrograde cavity preparation instrument. Endod Dent Traumatol 1995;11:177– 80.23. Devall R, Lumley P, Wamplington M, Blunt L. Cutting characteristics of a sonic

root-end preparation instrument. Endod Dent Traumatol 1996;12:96 –9.24. Bertrand G, Festal F, Barailly R. Use of ultrasound in apicoectomy. Quintessence Int

1976;7:9 –12.25. Flath RK, Hicks ML. Retrograde instrumentation and obturation with new devices.

J Endod 1987;13:546 –9.26. von Arx T, Walker WA. Microsurgical instruments for root-end cavity preparation

following apicoectomy: a literature review. Endod Dent Traumatol 2000;16:47– 62.27. Kim S, Kratchman S. Modern endodontic surgery concepts and practice: a review.

J Endod 2006;32:601–23.28. Gutmann JL, Harrison JW. Posterior endodontic surgery: anatomical considerations

and clinical techniques. Int Endod J 1985;18:8 –34.29. Kim S. Principles of endodontic microsurgery. Dent Clin North Am 1997;41:

481–97.30. Kellert M, Solomon C, Chalfin H. A modern approach to surgical endodontics:

ultrasonic apical preparation. N Y State Dent J 1994;60:25– 8.31. Rubinstein R, Torabinejad M. Contemporary endodontic surgery. J Calif Dent Assoc

2004;32:485–92.32. Mehlhaff DS, Marshall JG, Baumgartner JC. Comparison of ultrasonic and high-

speed-bur root-end preparations using bilaterally matched teeth. J Endod 1997;23:448 –52.

33. Gutmann JL, Saunders WP, Nguyen L, Guo IY, Saunders EM. Ultrasonic root-endpreparation: Part 1. SEM analysis. Int Endod J 1994;27:318 –24.

34. Engel TK, Steiman HR. Preliminary investigation of ultrasonic root end preparation.J Endod 1995;21:443–5.

35. Gorman MC, Steiman HR, Gartner AH. Scanning electron microscopic evaluation ofroot-end preparations. J Endod 1995;21:113–7.

36. Lin CP, Chou HG, Kuo JC, Lan WH. The quality of ultrasonic root-end preparation: aquantitative study. J Endod 1998;24:666 –70.

37. Khabbaz MG, Kerezoudis NP, Aroni E, Tsatsas V. Evaluation of different methods forthe root-end cavity preparation. Oral Surg Oral Med Oral Pathol Oral Radiol Endod2004;98:237– 42.

38. Abedi HR, Van Mierlo BL, Wilder-Smith P, Torabinejad M. Effects of ultrasonicroot-end cavity preparation on the root apex. Oral Surg Oral Med Oral Pathol OralRadiol Endod 1995;80:207–13.

39. Rud J, Andreasen JO, Moller-Jensen JE. A follow-up study of 1000 cases treated by
endodontic surgery. Int J Oral Surg 1972;1:15–28.

40. Amagasa T, Nagase M, Sato T, Shioda S. Apicoectomy with retrograde gutta-percharoot filling. Oral Surg Oral Med Oral Pathol 1989;68:339 – 42.

41. Tidmarsh BG, Arrowsmith MG. Dentinal tubules at the root ends of apicected teeth:a scanning electron microscopic study. Int Endod J 1989;22:184 –9.

42. Shani J, Friedman S, Stabholtz A, Abed JA. Radionuclide model for evaluating seal-ability of retrograde filling materials. Int J Nucl Med Biol 1984;11:46 –51.

43. Vertucci F, Beatty RG. Apical leakage associated with retrofilling techniques: a dyestudy. J Endod 1986;12:331– 6.

44. Gilheany PA, Figdor D, Tyas MJ. Apical dentin permeability and microleakage asso-ciated with root end resection and retrograde filling. J Endod 1994;20:22– 6.

45. Gagliani M, Taschieri S, Molinari R. Ultrasonic root-end preparation: influence ofcutting angle on the apical seal. J Endod 1998;24:726 –30.

46. Weller RN, Niemczyk SP, Kim S. Incidence and position of the canal isthmus.J Endod 1995;21:380 –3.

47. Hsu Y-Y, Kim S. The resected root surface: the issue of canal isthmuses. Dent ClinNorth Am 1997;41:529 – 40.

48. Zuolo ML, Perin FR, Ferreira MOF, Faria FP. Ultrasonic root-end preparation withsmooth and diamond-coated tips. Endod Dent Traumatol 1999;15:265– 8.

49. O’Connor RP, Hutter JW, Roahen JO. Leakage of amalgam and Super-EBA root-endfillings using two preparation techniques and surgical microscopy. J Endod1995;21:74 – 8.

50. Sultan M, Pitt-Ford TR. Ultrasonic preparation and obturation of root-end cavities.Int Endod J 1995;28:231– 8.

51. Pashley DH. Smear layer: physiological considerations. Oper Dent 1984; Suppl3:13–29.

52. Saunders WP, Saunders EM, Gutman JL. Ultrasonic root-end preparation: Part 2.Microleakage of EBA root-end fillings. Int Endod J 1994;27:325–9.

53. Lloyd A, Gutmann J, Dummer P, Newcombe R. Microleakage of Diaket and amalgamin root-end cavities prepared using MicroMega sonic retro-prep tips. Int Endod J1997;30:196 –204.

54. Chailertvanitkul P, Saunders WP, Saunders EM, MacKenzie D. Polymicrobial coro-nal leakage of super EBA root-end fillings following two methods of root-end prep-aration. Int Endod J 1998;31:348 –53.

55. Karlovic Z, Pezelj-Ribaric S, Miletic I, Jukic S, Grgurevic J, Anic I. Erbium:YAG laserversus ultrasonic in preparation of root-end cavities. J Endod 2005;31:821–3.

56. Walmsley AD, Lumley PJ, Johnson WT, Walton RE. Breakage of ultrasonic root-endpreparation tips. J Endod 1996;22:287–9.

57. Taschieri S, Testori T, Francetti L, Del Fabbro M. Effects of ultrasonic root endpreparation on resected root surfaces: SEM evaluation. Oral Surg Oral Med OralPathol Oral Radiol Endod 2004;98:611– 8.

58. Gondim E Jr, Figueiredo Almeida de Gomes BP, Ferraz CC, Teixeira FB, de Souza-Filho FJ. Effect of sonic and ultrasonic retrograde cavity preparation on the integrityof root apices of freshly extracted human teeth: scanning electron microscopyanalysis. J Endod 2002;28:646 –50.

59. Onnick PA, Davis RD, Wayman BE. An in vitro comparison of incomplete rootfractures associated with three obturation techniques. J Endod 1994;20:32–7.

60. Waplington M, Lumley PJ, Walmsley AD. Incidence of root face alteration afterultrasonic retrograde cavity preparation. Oral Surg Oral Med Oral Pathol OralRadiol Endod 1997;83:387–92.

61. Brent PD, Morgan LA, Marshall JG, Baumgartner JC. Evaluation of diamond-coatedultrasonic instruments for root-end preparation. J Endod 1999;25:672–5.

62. Lin CP, Chou HG, Chen RS, Lan WH, Hsieh CC. Root deformation during root-endpreparation. J Endod 1999;25:668 –71.

63. Frank RJ, Antrim DD, Bakland LK. Effect of retrograde cavity preparations on rootapexes. Endod Dent Traumatol 1996;12:100 –3.

64. Beling KL, Marshall JG, Morgan LA, Baumgartner JC. Evaluation for cracks associ-ated with ultrasonic root-end preparation of gutta-percha filled canals. J Endod1997;23:323– 6.

65. Min MM, Brown CE Jr, Legan JJ, Kafrawy AH. In vitro evaluation of effects of ultra-sonic root-end preparation on resected root surfaces. J Endod 1997;23:624 – 8.

66. Calzonetti KJ, Iwanowski T, Komorowski R, Friedman S. Ultrasonic root-end cavitypreparation assessed by an in situ impression technique. Oral Surg Oral Med OralPathol Oral Radiol Endod 1998;85:210 –5.

67. Morgan LA, Marshall JG. A scanning electron microscopic study of in vivo ultrasonicroot-end preparations. J Endod 1999;25:567–70.

68. Gray GJ, Hatton JF, Holtzmann DJ, Jenkins DB, Nielsen CJ. Quality of root-endpreparations using ultrasonic and rotary instrumentation in cadavers. J Endod2000;26:281–3.

69. Rainwater A, Jeansonne BG, Sarkar N. Effects of ultrasonic root-end preparation onmicrocrack formation and leakage. J Endod 2000;26:72–5.

70. Peters CI, Peters OA, Barbakow F. An in vitro study comparing root-end cavitiesprepared by diamond-coated and stainless steel ultrasonic retrotips. Int Endod J
2001;34:142– 8.

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

22

2

2

2

2

2

2

2

2

2

2

2

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

Review Article

9

71. Navarre SW, Steiman HR. Root-end fracture during retropreparation: a comparisonbetween zirconium nitride-coated and stainless steel microsurgical ultrasonic in-struments. J Endod 2002;28:330 –2.

72. Ishikawa H, Sawada N, Kobayashi C, Suda H. Evaluation of root-end cavity prepara-tion using ultrasonic retrotips. Int Endod J 2003;36:586 –90.

73. Holland R, Otoboni Filho JA, Bernabè PF, de Souza V, Nery MJ, Dezan Junior E. Effectof root canal filling material and level of surgical injury on periodontal healing indogs. Endod Dent Traumatol 1998;14:199 –205.

74. Gondim E Jr, Zaia AA, Figueiredo Almeida de Gomes BP, Ferraz CC, Teixeira FB, deSouza-Filho FJ. Investigation of the marginal adaptation of root-end filling materialsin root-end cavities prepared with ultrasonic tips. Int Endod J 2003;36:491–9.

75. Sumi Y, Hattori H, Hayashi K, Ueda M. Titanium-inlay: a new root-end filling mate-rial. J Endod 1997;23:121–3.

76. Bader G, Lejeune S. Prospective study of two retrograde endodontic apical prepa-rations with and without the use of CO2 laser. Endod Dent Traumatol 1998;14:75– 8.

77. Rubinstein RA, Kim S. Short-term observation of the results of endodontic surgerywith the use of a surgical operation microscope and Super-EBA as root-end fillingmaterial. J Endod 1999;25:3– 8.

78. Testori T, Capelli M, Milani S, Weinstein RL. Success and failure in periradicularsurgery: a longitudinal retrospective analysis. Oral Surg Oral Med Oral Pathol OralRadiol Endod 1999;87:493– 8.

79. Zuolo ML, Ferreira MOF, Gutmann JL. Prognosis in periradicular surgery: a clinicalprospective study. Int Endod J 2000;33:91– 8.

80. von Arx T, Gerber C, Hardt N. Periradicular surgery of molars: a prospective clinicalstudy with a one-year follow-up. Int Endod J 2001;34:520 –5.

81. Rubinstein RA, Kim S. Long-term follow-up of cases considered healed one yearafter apical microsurgery. J Endod 2002;28:378 – 83.

82. Maddalone M, Gagliani M. Periapical endodontic surgery: a 3-year follow-up study.Int Endod J 2003;36:193– 8.

83. Taschieri S, Del Fabbro M, Testori T, Francetti L, Weinstein R. Endodontic surgerywith ultrasonic retrotips: one-year follow-up. Oral Surg Oral Med Oral Pathol OralRadiol Endod 2005;100:380 –7.

84. Tsesis I, Rosen E, Schwartz-Arad D, Fuss Z. Retrospective evaluation of surgicalendodontic treatment: traditional versus modern technique. J Endod 2006;32:412– 6.

85. Tanzilli JP, Donald R, Moodnik RM. A comparison of the marginal adaptation ofretrograde techniques: a scanning electron microscopic study. Oral Surg Oral MedOral Pathol 1980;50:74 – 80.

86. Mattison GD, Von Fraunhofer A, Delivanis PD, Anderson AN. Microleakage of ret-rograde amalgams. J Endod 1985;11:340 –5.

87. Carr G. Ultrasonic root-end preparation. Dent Clin North Am 1997;41:541–54.88. Siqueira JF Jr. Endodontic infections: concepts, paradigms, and perspectives. Oral

Surg Oral Med Oral Pathol Oral Radiol Endod 2002;94:281–93.89. Siqueira JF Jr, Lopes HP. Bacteria on the apical root surfaces of untreated teeth with

periradicular lesions: a scanning electron microscopy study. Int Endod J 2001;34:216 –20.

90. Barnett F, Godick B, Tronstad L. Clinical suitability of a sonic vibratory endodonticinstrument. Endod Dent Traumatol 1985;1:77– 81.

91. Barnett F, Trope M, Khoja M. Tronstad L.Bacteriological status of the root canal aftersonic, ultrasonic and hand instrumentation. Endod Dent Traumatol 1985;1:228 –31.

92. Tronstad L, Barnett F, Schawartzben L, Frasca P. Effectiveness and safety of a sonicvibratory endodontic instrument. Endod Dent Traumatol 1985;1:69 –76.

93. Nehammer CF, Stock CJR. Endodontics in practice: preparation and filling of theroot canal. Br Dent J 1985;158:285–91.

94. Tang MP, Stock CJ. An in vitro method for comparing the effects of different rootcanal preparation techniques on the shape of curved root canals. Int Endod J1989;22:49 –54.

95. Tang MPF, Stock CJR. The effect of hand, sonic and ultrasonic instrumentation onthe shape of curved root canals. Int Endod J 1989;22:55– 63.

96. Prati C, Selighini M, Ferrieri P, Mongiorgi R. Scanning electron microscopic eval-uation of different endodontic procedures on dentin morphology of human teeth. JEndod 1994;20:174 –9.

97. Miserendino LJ, Miserendino CA, Moser JB, Heuer MA, Osetek EM. Cutting efficiencyof endodontic instruments: Part III. Comparison of sonic and ultrasonic instrumentsystems. J Endod 1988;14:24 –30.

98. Hennequin M, Andre JF, Botta G. Dentin removal efficiency of six endodontic sys-tems: a quantitative comparison. J Endod 1992;18:601– 4.

99. Gulabivala K, Briggs PF, Setchell DJ. A comparison of the dentine-removing char-acteristics of two endosonic units. Int Endod J 1993;26:26 –36.

00. Lumley PJ, Blunt L, Walmsley AD, Marquis PM. Analysis of the surface cut by sonicfiles. Endod Dent Traumatol 1996;12:240 –5.

01. Lumley PJ, Harrington E, Aspinwall E, Blunt L, Walmsley AD, Marquis PM. Factors
affecting the cutting ability of sonic files. Int Endod J 1996;29:173– 8.
4 Plotino et al.

02. Lumley PJ, Harrington E, Marquis PM, Walmsley AD. Intra-canal cutting ability ofMM1500 files. Int Endod J 1996;29:309 –14.

03. Rodrigues HH, Biffi JC. A histobacteriological assessment of nonvital teeth afterultrasonic root canal instrumentation. Endod Dent Traumatol 1989;5:182–7.

04. Ahmad M, Pitt Ford TR, Crum LA, Wilson RF. Effectiveness of ultrasonic files inthe disruption of root canal bacteria. Oral Surg Oral Med Oral Pathol 1990;70:328 –32.

05. Chenail BL, Teplitsky PE. Endosonics in curved root canals. J Endod 1985;11:369 –74.

06. Kielt LW, Montgomery S. The effect of endosonic instrumentation in simulatedcurved root canals. J Endod 1987;13:215–9.

07. Ahmad M, Pitt Ford TR. Comparison of two ultrasonic units in shaping simulatedcurved canals. J Endod 1989;15:457– 62.

08. Dummer PMH, Alodeh MHA, Doller R. Shaping of simulated root canals in resinblocks using files activated by a sonic handpiece. Int Endod J 1989;22:211–25.

09. Murgel C, Walmsley AD, Walton RE. The efficacy of step-down procedures duringendosonic instrumentation. J Endod 1991;17:111–5.

10. Lumley PJ, Walmsley AD. Effect of precurving on the performance of endosonic Kfiles. J Endod 1992;18:232– 6.

11. Lumley PJ, Walmsley AD, Walton RE, Rippin JW. Effect of precurving endosonic fileson the amount of debris and smear layer remaining in curved root canals. J Endod1992;18:616 –9.

12. Briseno BM, Sobarzo-Navarro V, Devens S. The influence of different engine-driven,sound ultrasound systems and the Canal Master on root canal preparation: anin vitro study. Int Endod J 1993;26:190 –7.

13. Torabinejad M. Passive step-back technique: A sequential use of ultrasonic andhand instruments. Oral Surg Oral Med Oral Pathol 1994;77:402–5.

14. Lumley PJ, Walmsley AD. Inherent variability in the power output of endosonicinstruments. Int Endod J 1991;24:298 –302.

15. Lumley PJ, Walmsley AD, Laird W. Streaming patterns produced around endosonicfiles. Int Endod J 1991;24:290 –7.

16. Lumley PJ, Walmsley AD, Thomas A. An in vitro investigation into the cutting abilityof ultrasonic K files. Endod Dent Traumatol 1994;10:264 –7.

17. Lumley PJ. Factors affecting the wear of sonic files. Endod Dent Traumatol1996;12:197–201.

18. Lumley PJ, Harrington E, Walmsley AD, Marquis PM. Taper and stiffness of sonicendodontic files. Endod Dent Traumatol 1996;12:77– 81.

19. Martin H, Cunningham W. The effect of endosonic and hand manipulation on theamount of root canal material extruded. Oral Surg Oral Med Oral Pathol1982;53:611–3.

20. Martin H, Cunningham W. An evaluation of postoperative pain incidence followingendosonic and conventional root canal therapy. Oral Surg Oral Med Oral Pathol1982;54:74 – 6.

21. McKendry DJ. Comparison of balanced forces, endosonic, and step-back fillinginstrumentation techniques: quantification of extruded apical debris. J Endod1990;16:24 –7.

22. Lee SJ, Strittmatter EJ, Lee CS. A comparison of root canal content extrusion usingultrasonic and hand instrumentation. Endod Dent Traumatol 1991;7:65– 8.

23. Vansan LP, Pecora JD, da Costa WF, Silva RG, Savioli RN. Comparative in vitro studyof apically extruded material after four different root canal instrumentation tech-niques. Braz Dent J 1997;8:79 – 83.

24. Pedicord D, el Deeb ME, Messer HH. Hand versus ultrasonic instrumentation: itseffect on canal shape and instrumentation time. J Endod 1986;12:375– 81.

25. Reynolds MA, Madison S, Walton RE, Krell KV, Rittman BR. An in vitro histologicalcomparison of the step-back, sonic, and ultrasonic instrumentation techniques insmall, curved root canals. J Endod 1987;13:307–14.

26. Baker MC, Ashrafi SH, Van Cura JE, Remeikis NA. Ultrasonic compared withhand instrumentation: a scanning electron microscope study. J Endod 1988;14:435– 40.

27. Chenail BL, Teplitsky PE. Endosonics in curved root canals: Part II. J Endod1988;14:214 –7.

28. Goldberg F, Soares I, Massone EJ, Soares IM. Comparative debridement study be-tween hand and sonic instrumentation of the root canal. Endod Dent Traumatol1988;4:229 –34.

29. Ahmad M, Pitt Ford TR. A comparison using a microradiography of canal shapes inteeth instrumented ultrasonically and by hand. J Endod 1989;15:339 – 44.

30. Biffi JCG, Rodrigues HH. Ultrasound in endodontics: a quantitative and histologicalassessment using human teeth. Endod Dent Traumatol 1989;5:5– 62.

31. Briggs PF, Gulabivala K, Stock CJ, Setchell DJ. Dentine-removing characteristics ofan ultrasonically energized K-file. Int Endod J 1989;22:259 – 68.

32. DeNunzio MS, Hicks ML, Pelleu GB Jr, Kingman A, Sauber JJ. Bacteriological com-parison of ultrasonic and hand instrumentation of root canals in dogs. J Endod1989;15:290 –3.

33. Ehrlich AD, Boyer TJ, Hicks ML, Pelleu GB. Effects of sonic instrumentation on the
apical preparation of curved canals. J Endod 1989;15:200 –3.

3

3

3

3

3

3

3

3

3

3

3

3

3

Review Article

J

34. Loushine RJ. Weller RN, Hartwell GR. Stereomicroscopic evaluation of canalshape following hand, sonic and ultrasonic instrumentation. J Endod1989;15:417–21.

35. Pugh RJ, Goerig AC, Glaser CG, Luciano WJ. A comparison of four endodonticvibratory systems. Gen Dent 1989;37:296 –301.

36. Walker TL, del Rio CE. Histological evaluation of ultrasonic and sonic instrumen-tation of curved root canals. J Endod 1989;15:49 –59.

37. Walker TL, del Rio CE. Histological evaluation of ultrasonic debridement comparingsodium hypochlorite and water. J Endod 1991;17:66 –71.

38. Mandel E, Machtou P, Friedman S. Scanning electron microscope observation ofcanal cleanliness. J Endod 1990;16:279 – 83.

39. Walmsley AD, Murgel C, Krell KV. Canal markings produced by endosonic instru-ments. Endod Dent Traumatol 1991;7:84 –9.

40. Yahaya AS, El Deeb ME. Effect of sonic versus ultrasonic instrumentation on canal
preparation. J Endod 1989;15:235–9.

41. Smith RB, Edmunds DH. Comparison of two endodontic handpieces during thepreparation of simulated root canals. Int Endod J 1997;30:369 – 80.

42. Smith RB, Edmunds DJ. Comparison of two endodontic handpieces during thepreparation of root canals in extracted human teeth. Int Endod J 1998;31:22–31.

43. Walmsley AD, Lumley PJ, Laird WR. Oscillatory pattern of sonically powered end-odontic files. Int Endod J 1989;22:125–32.

44. Haidet J, Reader A, Beck M, Meyers W. An in vitro comparison of the step-backtechnique versus step-back/ultrasonic technique in human mandibular molars.J Endod 1989;15:195–9.

45. Metzler RS, Montgomery S. The effectiveness of ultrasonics and calcium hydroxidefor debridement of human mandibular molars. J Endod 1989;15:373– 8.

46. Archer R, Reader A, Nist R, Beck M, Meyers M. An in vivo evaluation of the efficacyof ultrasound after step-back preparation in mandibular molars. J Endod 1992;18:
549 –52.

ultrasonics in endodontics: a review of the literature · 2012-06-05 · ultrasonics in...

Documents