Endod Dent Traumatot 1997; 13: 69-74Printed in Denmark . Alt rigtits reserved

Copyright © Munksgaard 1997

Endodontics &Dental Traumatology

ISSN 0109-2502

Periapical status, quality of root canal fillingsand estimated endodontic treatment needs inan urban German populationWeiger R, Hitzler S, Hermle G, Lost C. Periapical status, qualityof root canal fillings and estimated endodontic treatment needs inan urban German population Endod Dent Traumatol 1997;13: 69-74. © Munksgaard, 1997.

Abstract The objective of this study was to determine the peri-apical status and the quality of root canal fillings and to estimatethe endodontic treatment needs in a German population. Glinicaland radiographic data and the operative procedures performed wereevaluated on 323 patients coming to a dental surgery in Stuttgart,Germany, in 1993. In 182 individuals at least one tooth exhibiteda root canal filling, a necrotic pulp or an irreversible pulpitis. Outof the 7897 teeth examined, 215 (2.7%) had a root canal treat-ment (category A), 122 being non-endodontically treated (1.5%)did not respond to the sensitivity test (categoiy B) and 53 (0.7%)were diagnosed as having irreversible infiamed pulp tissue (categoryG). The prevalence of teeth associated with radiographic signs ofperiapical pathosis was 61 % in the group of root canal filled teethand 88% in the group of pulpless and non-endodontically treatedteeth. Using the level and the density of the root canal filling ascriteria for evaluating the technical standard, only 14% of the endo-dontic treatments of non-apicectomized teeth were qualified as ade-quate. The minimal endodontic treatment need is 2.3% relatedto all examined teeth when the root canal filled teeth with clinicalsymptoms of periapical periodontitis (category A) and those ofcategories B and G are included. The real endodontic treatmentneed is suggested to be larger when considering that the technicalquality of the obturation is poor in most symptomless endodont-ically treated teeth associated with a periapical lesion. In the case ofretreatment of these teeth, the endodontic treatment need woLildthen be calculated at 3.7%.

R. Weiger, S. Hitzler, G. Hermie,C. LostDepartment of Conservative Dentistry,University of Tubingen, Germany

Key words; endodontics; epidemiology; root canaltreatment

R. Weiger, Abteilung Poliklinik fur Zahnerhaltung,ZMK-Klinik, Osianderstr. 2-8, W-72076 Tubingen,Germany

Accepted September 14, 1996

Epidemiological data on the periapical status, thequality of root canal treatments and the endodontictreatment needs in Germany are scarce. Three studies(1-3) have been performed analysing selected patientgroups of a University dental clinic. Attention wasfocused on the prevalence and the quality of root ca-nal fillings by evaluation of intraoral or panoramicradiographs. In one paper only (2), an attempt wasmade to estimate radiographically the need for endo-

dontic treatment in 200 individuals suffering fromperiodontal diseases. Glinical examinations, includingsensitivity tests or the results of operative procedureswhich could probably reveal the need for additionalroot canal treatments, were not considered.

In Germany, the number of specialists focusing onclinical endodontics is negligible. The vast majority ofpatients seeking dental care or emergency treatmentwill primarily consult general dental practitioners. In

69

Weiger et al.

Table 1. Age distribution of the patient sample (n=323). Group I representsthe patients having at least one tooth with an obturated root canal or onetooth associated with an irreversibly inflamed or necrotic pulp. This type oftooth is not present in the individuals of Group II

Age group

12-1920-2930-3940-4950-5960-6970-7980-89

Group 1

6585122229

122

182

Group II

1566361262--

141

Total (%)

21 (6.5%)124 (38.4%)87 (26.9%)34 (10.5%)28 (8.7%)11 (3.4%)16 (5.0%)2 (0.6%)

323 (100.0%)

contrast, patients of a dental clinic affiliated with aUniversity are frequently referrals or have specialdental problems, thus representing a highly selectedmaterial. This study was designed to determine retro-spectively the periapical status and the quality of rootcanal fillings in indi\n.duals seeking examination/treatment in a selected German general dentalsurgery. Furthermore, an estimation of their endo-dontic treatment was done on the basis of clinical andradiographic data and of the operative proceduresperformed accordingly.

Material and methods

Patients who came to a general dental practice duringthe regular consultation hours for the first time orafter a period of 5 years in 1993 were included inthis study. Three full-time general dental practitionersexamined and treated the patients in their privatesurgery situated in the centre of Stuttgart, a city withabout 600,000 inhabitants in the southern part ofGermany. Ghildren less than 12 years old were notconsidered in this study. Out of the 323 subjectsexamined, 54% were females and 46% males. Theaverage patient age was 35.2 years. The age distri-bution is illustrated in Table 1. The patients' recordsincluding intraoral and/or panoramic radiographsformed the basis for the study.

Clinical criteria

The recorded history of dental pain, if present, andthe outcomes of the clinical examination were evalu-ated for each patient. The criteria listed in a specialform included clinical symptoms indicating sympto-matic pulpitis or an endodontically induced periapicalperiodontitis, tooth vitality, potential causes for pulpalinvolvement, type of coronal restoration and marginalseal of the restoration (Table 2). Third molars wereexcluded from the analysis.

Radiographic criteria

Periapical radiographs were available for most teethwhich did not clearly respond to the sensitixdty test.In some patients, panoramic radiographs had beentaken for other reasons. All films were processed ina standardized automated machine. Radiographswhich were not available or which did not allow aproper evaluation of any single criteria of interest dueto technical shortcomings or overprojections of ana-tomical structures were separately registered.

A tooth with radiopaque material within the con-fines of the suggested root canal(s) was rated as "endo-dontically treated" tooth. Signs of periapical pathosis,the density of the root canal filling and its apical ex-tension related to the radiographic apex and the pres-ence of an intracanal post were recorded (Table 2).The widening of the periapical periodontal ligamentspace exceeding about two times the width of a nor-mal lateral periodontal ligament space was assessedas "periapical radiolucency". Multi-rooted teeth werecategorized according to the root with the most insuf-ficient root canal filling and/or with the highest peri-apical score.

Radiographic interpretation

In the preliminary^ phase of the study, a prior cali-bration of two dentists (SH and GH) was carried outby an experienced endodontist (RW). Thirty-oneradiographs showing teeth with obturated root canals

Table 2. Clinical and radiographical criteria for categorization of the teeth

Clinical symptoms• absent• present

Sensitivity test• positive• negative

Coronal restoration• no restoration• crown (or filling)• crown (or filling) with intracanal post

Marginal seal of the restoration• sufficient• insufficient

Radiolucency• absent• present

Apical level of the root canal filling• 0-2 mm short of the radiographic apex• >2 mm short of the radiographic apex• extruded beyond fhe radiographic apex

Density of the root canal filling• no voids and close adaptation to root canal walls• voids and/or insufficient adaptation to root canal walls

Causes for irreversible pulpitis• caries• trauma• unclear

70

Weiger et al.

Table 5. Distribution of the teeth of category A according to tooth group, periapical radiolucency, density and length of the root canal filling and marginal seal ofcoronal restoration (u.: upper, I.: lower, ant.: anterior, apicect.: apicectomized, ext.: extruded)

Category A

u. ant. teethu. premolarsu. molars1. ant. teeth1. premolars1. molarssubtotalapicect. teeth

total

n

5545284

2234

18827

215

Radiolucency

no

202012-119

7211

83

yes

3525164

1125

11616

132

Density

+

1518328

105615

71

-

4027252

1424

13212

144

0-2

291352

108

6722

89

Length

>2

1928222

1123

1053

108

ext.

741

—13

162

18

Marginal

+

4325162

1419

11922

141

seal

-

12201228

15695

74

endodontic treatment need would then be calculatedat approximately 3.7%.

Discussion

The study material consisting of patients from a gen-eral dental practice does not represent a randomsample of the German population in the area ofStuttgart. However, it may provide useful data on theendodontic quality and the endodontic treatmentneeds in Germany compared to a highly selected pa-

Table 6. Distribution of the teeth of category B according to tooth group,periapical radiolucency and type of restoration (u.: upper, I.: lower, ant.: an-terior)

Category B

u. ant. teethu. premolarsu. molars1. ant. teeth1. premolars1. molars

total

n

3813219

2120

122

Radiolucency

no

621132

15

yes

3211208

1818

107

Restoration

no

162

10763

44

yes

2211112

1517

78

Table 7. Distribution of the teeth of category C according to tooth group,periapical radiolucency, type of restoration and causes for pulpal involvement(u.: upper, I.: lower, ant.: anterior, car.: caries, trau.: trauma, un.: unclear)

Category C

u. ant. teethu. premolarsu. molars1. ant. teeth1. premolars1. molars

total

n

5111517

14

53

Radiolucency

no

148163

23

yes

477—1

11

30

Restoration

no

233122

12

yes

37

12—5

12

41

car

38

1515

13

45

Causes

trau.

1———2-

3

un.

13———1

5

tient population of a dental school clinic affiliatedwith a university. Such patient groups have served asa basis for more recent investigations (1^3) docu-menting the prevalence and the quality of endodontictreatment as well as the periapical status.

The present study was restricted to patients whocame to the selected dental surgery for the first timeor after a period of at least 5 years. The reasons whythese subjects chose this practice have not been re-corded. Of the 323 patients, women dominatedslightly with 54%. The age distribution clearlyshowed that the younger individuals (12^39 years)made up 72% of the whole sample. The averagenumber of remaining teeth per individual was 24(third molars excluded). How far this figure is com-parable with that of the whole German populationcould not be definitively assessed.

The patient's dental history, the clinical examin-ation and the operative procedures supply importantinformation about the presence of an irreversible pul-pitis, the potential causes of pulpal exposure and thenumber of pulpless teeth without any radiologicalsigns of periapical pathosis. However, a misdiagnosismade by one of the three practising dentists mightnot be completely excluded, possibly resulting in afalse treatment or a non-treatment. Particularly thesensitivity test on teeth with full ceramic crowns orwith radiographically obliterated root canals mightyield misleading results. Undoubtedly, the true endo-dontic treatment need can be estimated more com-prehensively when radiographic data are supple-mented by clinical findings.

Periapical radiographs or orthopantomogramswere used to evaluate the technical standard of rootcanal fillings and to detect periapical lesions. Thepresence or absence of periapical or lateral lesionswas assessed instead of applying a more detailed peri-apical scoring system according to 0rstavik et al. (4).In this connection, the widening of the periodontalligament space exceeding two times the width of thelateral periodontal ligament space was interpreted as

72

Endodontic status in a German population

Table 8. Prevalence of apical periodontitis and root canal fillings in Germany compared to some other European countries (ap. perio.: apical periodontitis; Ger:Germany; Neth: The Netherlands; Switz: Switzerland; Swe: Sweden; Nor: Norway)

Study

Present studyHulsmann et al. (1)Hulsmann et al. (2)Klimek et al. (3)DeCleen (13)Imfeld (14)Eckerbom et al. (15)Odesjoetal. (16)Eriksen & Bjertness (17)Eriksen etal. (18)

Country

GerGerGerGerNethSwitzSweSweNorNor

patient agein years

0 35.220->6020->600 41.1

20->5966

20->6020->60

5035(1984)35 (1993)

periapical

per person

0.75—

0.82—

1.031.181.280.550.870.380.15

periodontitis

% of teeth

3.0—3.4—

4.58.45.22.93.51.40.6

per person

0.670.780.900.990.532.843.181.621.470.940.36

root canal fillings

% of teeth %

2.73.23.84.62.3

20.313.08.66.03.41.3

with ap. perio.

6160584S39312625372638

an initial radiographic sign of periapical pathosis andclassified as periapical radiolucency. With respect tothe accuracy of diagnosing a periapical radiolucency,the intraoral radiograph was found to be somewhatsuperior to the panoramic one (5). Thus, in this studythe number of periapical lesions might be slightlyunderestimated unless periapical radiographs wereavailable.

The radiographic appearance of an obturated rootcanal is only a rough measure of the sealing capacityof a root canal filling. Neither the homogeneity northe apical extension related to the apical constrictioncan be exactly examined by using a radiograph takenin a bucco-oral direction (6). In vitro, not even a rootcanal filling of high quality seems to prevent the pene-tration of bacteria and microbial by-products alongthe obturated root canal (7, 8) unless a sufficient cor-onal restoration is present (9). At present, however,the only way of routinely judging the technical stan-dard of a root canal filling is offered by the radio-graph. Likewise, it has to be kept in mind that theoperator is not capable of radiographically assessingthe quality of the root canal debridement procedures.These limitations should be taken into account wheninterpreting the present results.

Endodontic treatment had been performed on2.7% of the teeth. Recently, slightly higher values(3.2"4.6%) were published for Germany (Table 8),which might be attributed to the highly selected pa-tient groups examined in these investigations. Incomparison with some other European countries, thecorresponding numbers also tended to be higher par-ticularly when older patients were investigated (Table8). In the present study, most (61%) of the teeth withobturated root canals were associated with a peri-apical lesion confirming the results of Hulsmann etal. (1, 2) and Klimek et al. (3). In Sweden, Norway,Switzerland and the Netherlands, however, this per-centage ranged between 25% and 39%, being mark-edly lower than that recorded in Germany (Table 8).

This obvious discrepancy might not only be due tothe different patient material examined but also toimproper techniques applied by some German den-tists combined with poor knowledge on the principlesof adequate endodontic treatment focusing on thecontrol and elimination of root canal infection. Thisassumption might be further supported by the resultsof the present study that the radiographic appear-ance of the root canal filling was satisfactory inlength and condensity in only 14% of the caseswhich have not been apicectomized. Most of the rootcanal fillings were not well condensed (66%) or end-ed more than 2 mm short of the radiographic apex(56%).

Out of the pulpless, non-endodontically treatedteeth, the vast majority (88%) showed radiographicsigns of periapical pathosis. In a German population,Hulsmann et al. (2) reported a similar percentage ofteeth with radiologically detectable periapical lesions.However, the real percentage may be still higherthan the calculated figures as lesions confined to can-cellous bone may not be detected in radiographs.Furthermore, it can only be speculated as to thecauses for the formation of the diagnosed endodont-ically induced lesions. Goronal leakage \da defect res-torations or deep carious lesions and traumatic in-juries might explain their occurrence. The smallestpercentage of teeth which needed endodontic treat-ment constituted the cases with an irreversible pul-pitits. Most of them had carious lesions compro-mising the pulp tissue. Molars were predominantlyassociated with a widening of the periapical peri-odontal ligament space, indicating a progressing in-fiammation in radicular portions of the pulp. Therewas no actual data from other studies concerning theprevalence of teeth with an irreversibly damagedpulp in an adult German population. The endodon-tic treatment need for the selected patient group canonly be estimated if consecutive cross-sectional orlongitudinal studies are performed. In the present

73