biomaterials science || dental implantation

882 SECTION II.5 Applications of Biomaterials

Ting, J. P., Willingham, S. B., & Bergstralh, D. T. (2008). NLRs at the intersection of cell death and immunity. Nat. Rev. Immu-nol., 8(5), 372–379.

Tipper, J. L., Hatton, A., Nevelos, J. E., Ingham, E., Doyle, C., et al. (2002). Alumina-alumina artificial hip joints. Part II: Characterisation of the wear debris from in vitro hip joint simulations. Biomaterials, 23(16), 3441–3448.

Urban, R. M., Hall, D. J., Sapienza, C. I., Jacobs, J. J., Sumner, D. R., et al. (1998). A comparative study of interface tissues in cemented vs. cementless total knee replacement tibial compo-nents retrieved at autopsy. Trans. SFB, 21.

Urban, R. M., Jacobs, J. J., Tomlinson, M. J., Gavrilovic, J., & Andersen, M. (1995). Migration of Corrosion Products from the Modular Head Junction to the Polyethylene Bearing Sur-face and Interface Membranes of Hip Prostheses. New York, NY: Raven Press.

Urban, R. M., Jacobs, J. J., Sumner, D. R., Peters, C. L., Voss, F. R., et al. (1996a). The bone–implant interface of femoral stems with non-circumferential porous coating: A study of speci-mens retrieved at autopsy. J. Bone Joint Surg. (Am.), 78-A(7), 1068–1081.

Urban, R. M., Jacobs, J. J., Tomlinson, M. J., Black, J., Turner, T. M., et al. (1996b). Particles of metal alloys and their corrosion products in the liver, spleen and para-aortic lymph nodes of patients with total hip replacement prosthesis. Orthop. Trans., 19, 1107–1108.

Urban, R. M., Jacobs, J., Gilbert, J. L., Rice, S. B., Jasty, M., et al. (1997). Characterization of solid products of corrosion gener-ated by modular-head femoral stems of different designs and materials. In D. E. Marlowe, J. E. Parr, & M. B. Mayor (Eds.), STP 1301 Modularity of Orthopedic Implants (pp. 33–44). Philadelphia, PA: ASTM.

Urban, R. M., Jacobs, J. J., Tomlinson, M. J., Gavrilovic, J., Black, J., et al. (2000). Dissemination of wear particles to the liver, spleen, and abdominal lymph nodes of patients with hip or knee replacement. J. Bone Joint Surg. (Am.), 82(4), 457–476.

van Ooij, A., Kurtz, S. M., Stessels, F., Noten, H., & van Rhijn, L. (2007). Polyethylene wear debris and long-term clinical failure of the Charite disc prosthesis: A study of 4 patients. Spine, 32(2), 223–229.

Venable, C. S., Stuck, W. G., & Beach, A. (1937). The effects on bone of the presence of metals; based upon electrolysis. An experimental study. Annals of Surgery, 105, 917.

Vermes, C., Chandrasekaran, R., Jacobs, J. J., Galante, J. O., Roebuck, K. A., et al. (2001a). The effects of particulate wear debris, cytokines, and growth factors on the functions of MG-63 osteoblasts. J. Bone Joint Surg. (Am.), 83(2), 201–211.

Vermes, C., Glant, T. T., Hallab, N. J., Fritz, E. A., Roebuck, K. A., et al. (2001b). The potential role of the osteoblast in the development of periprosthetic osteolysis: Review of in vitro osteoblast responses to wear debris, corrosion products, and cytokines and growth factors. J. Arthroplasty, 16(8 Suppl. 1), 95–100.

Visuri, T., & Koskenvuo, M. (1991). Cancer risk after Mckee- Farrar total hip replacement. Orthopedics, 14, 137–142.

von Knoch, M., Engh, C. A.S., Sychterz, C. J., Engh, C. A.J., & Willert, H. G. (2000). Migration of polyethylene wear debris in one type of uncemented femoral component with circumfer-ential porous coating: An autopsy study of 5 femurs. J Arthro-plasty, 15(1), 72–78.

Walker, P. S. (1978). Human Joints and Their Artificial Replace-ments. Springfield, IL: Charles C. Thomas.

Wiles, P. (1953). The surgery of the osteoarthritic hip. Brit. J. Surg., 45, 488.

Willert, H. G., & Semlitsch, M. (1977). Reactions of the articu-lar capsule to wear products of artificial joint prostheses. J. Biomed. Mater. Res., 11, 157–164.

Willert, H. G., Bertram, H., & Buchhorn, G. H. (1990). Osteolysis in alloarthroplasty of the hip. The role of ultra-high molecu-lar weight polyethylene wear particles. Clin. Orthop., 258, 95–107.

Wilson, J. N., & Scales, J. T. (1970). Loosening of total hip replace-ments with cement fixation. Clinical findings and laboratory studies. Clin. Orthop., 72, 145–160.

Wimmer, M., Berzins, A., Kuhn, H., Bluhm, A., Nassutt, R., et al. (1998). Presence of multiple wear directions in autopsy retrieved acetabular components. Trans. ORS, 23.

Wroblewski, B. M., Siney, P. D., Dowson, D., & Collins, S. N. (1996). Prospective clinical and joint simulator studies of a new total hip arthroplasty using alumina ceramic heads and cross-linked polyethylene cups. J. Bone Joint Surg. (Br.), 78(2), 280–285.

Yao, J., Glant, T. T., Lark, M. W., Mikecz, K., Jacobs, J. J., et al. (1995). The potential role of fibroblasts in periprosthetic oste-olysis: Fibroblast response to titanium particles. J. Bone Miner. Res., 10(9), 1417–1427.

CHAPTER II.5.7 DENTAL IMPLANTATION

Jack E. Lemons1 and Carl E. Misch2

1University Professor, Schools of Dentistry, Medicine and Engineering, University of Alabama at Birmingham, Birmingham, AL, USA2DDS, MDS, Misch International Institute, Beverly Hills, MI, USA

PATIENT PROFILES, DENTAL NEEDS, AND SURGICAL IMPLANTS: 1950S–2010S

Functional, aesthetic, and general health compromises have been correlated with the loss of oral dentition. The dental profession has developed a wide range of treat-ments to deal with dentition losses and oral diseases; however, a significant percentage of the world popula-tion continues to lose teeth progressively with dental diseases and aging. In recent decades, since the 1950s, the modern era of treatments based on surgical implants

has evolved. Significant advances in quality and quantity have occurred during each decade. In the USA, a larger population of completely edentulous individuals existed in the 1950s, and many implant treatments were initially designed to support full arch implant supported remov-able dentures (Misch, 1999). A prominent design was the subperiosteal type (Figure II.5.7.1A,B,C), where a cast cobalt alloy metallic framework was fabricated and implanted under the periosteum and fitted to surface fea-tures of the bone anatomy (Rizzo, 1988). Posts extended through the gingival and mucosal soft tissues and the implant denture was directly supported on bone without significant soft tissue contact. The surgical and implant fabrication procedures were technically demanding for the various subperiosteal implant designs. A group of dentists and supporting staff emerged as the experts in this subdiscipline.

Early subperiosteal systems were shown to func-tion through implant-to-soft tissue interfaces and many

ChapTEr II.5.7 Dental Implantation 883

supported the relative benefits of fibrous tissue integra-tion (James, 1983). A subdiscipline network of education evolved with the subperiosteal designs; however, many dental professionals started to support the merits of other types of implant designs. In all situations, the den-tal implant “experts” were required to coordinate a wide range of technologies, including implant design, fabrica-tion, finishing, and placement, plus the various aspects of intra-oral prosthetic restorations and long-term mainte-nance. Some supported the concept of plate (blade) form implant designs (Figure II.5.7.2), where the body of the implant was placed into a surgically prepared slot in the bone (Weiss, 1986). In part due to implant design, and in part due to “immediate restoration” and oral func-tion, many of the plate form and related designs of dental implant systems were shown to function through fibrous tissue and/or fibrous–osseous type tissue interfaces (James and Keller, 1974). Some called the interfacial tis-sue zone a “pseudo-ligament,” and described properties somewhat similar to the natural tooth periodontal liga-ment. One aspect of the plate form implant was the inten-tion to have a condition like the tooth-to-bone interfacial zone. With systems evolution, treatments extended from fully endentulous to partially edentulous regions of the mandibular and maxillary arches.

The dental community followed multiple avenues for dental implant designs and intraoral restorations, depending on their backgrounds, the patient popula-tion being treated, and recognized needs for improved

(A) (B)

(D)(C)

FIGURE II.5.7.1 A, A panoramic radiograph of a severely resorbed mandible, measuring less than 3 mm in height. B, A postoperative panoramic radiograph of an iliac crest bone graft wired around the atrophic mandible (1983). C, Reentry after 6 months into the iliac crest bone graft and a subperiosteal implant inserted (1983). D, Postoperative panoramic radiograph of the iliac crest graft after maturity and the subperiosteal implant (1987).

FIGURE II.5.7.2 Plate (blade) form implant design.


treatments. One system was called the Ramus Frame (Figure II.5.7.3A,B,C), another the Transosseous and/or the Staple design (Figure II.5.7.4). Each had relative merits which have been described in articles and books associated with dental implants.

As another extension of pre-1950s studies, some in the dental implant profession supported root-form type designs (Figure II.5.7.5 and Figure II.5.7.6), often made in the shape of helical formed wires, pins, rods, screws or plateaus for the body sections of the implants that

(A) (B)

(C)

FIGURE II.5.7.3 (A) Schematic of insertion into Mandibular Bone; (B) Schematic of Ramus Frame Seated into Bone; (C) Radiograph of Ramus Frame Mandibular Inplant.

FIGURE II.5.7.4 Transosseous and/or the Staple design.

FIGURE II.5.7.5 Root-form type designs.


were placed into the bone (called endosseous or end-osteal devices) (Cranin, 1970; Branemark et al., 1977; Small, 1980; Schnitman, 1987; Misch, 1999). Early in development, dental implants were primarily uniblock (single piece) systems combined with existing (known) intraoral restorative procedures for removable, fixed, and fixed-removable intraoral prosthetics.

The range of materials and biomaterials used for den-tal implants included available surgical implant grade metallics, ceramics, polymerics, mechanical mixtures, and composites. During this period, groups championed different concepts where the implants were made from metallics, and one of the more popular root forms sup-ported primarily by dental specialists was the two-stage endosteal screw type implant. The abutment and implant components were assembled after a controlled period of post-surgical healing of bone and soft tissues. One of these early designs was fabricated from vitreous carbon, and initial studies supported the merits of this bioma-terial for this application (Rizzo, 1988; Meffert et al., 1992). These approaches were popularized internation-ally, and the use of dental implants continued to increase with experience and time. During the 1980s and 1990s multiple clinical trials were completed showing the rela-tive merits of implant-based treatments. One aspect of this evolution was the impact from the biomaterial and biomechanical disciplines which strongly influenced the overall enhancements of implant bulk and surface prop-erties (Lemons, 1999).

As an example of interdisciplinary coordinations, the original subperiosteal and plate form dental implants have been redesigned in shape, surface biomaterial, and the surgical-restorative techniques to provide an osseous inte-grated dental implant system (now called Custom Osse-ous Integrated Implant or COII for these systems) (Baker et al., 2010). This same philosophy is being extended into on-going and planned (future) investigations in implant dentistry.

ANATOMICAL AND IMAGING CONSIDERATIONS

The overall maxillary and mandibular bone anatomies and regions for possible dental implant treatments are

described in prior books. In general, the subperiosteal implants were placed onto the surface anatomy of the fully edentulous and axillary or mandibular bone. In part because of bone structure, subperiosteal implants in mandibular regions, when compared to maxillary implants, were more stable over time. The plate-form implants were initiated primarily for use in the edentu-lous posterior mandible, while the anterior, maxillary, and mandibular regions were selected for initial studies of root-form implant placement. This was in part because of available dimensions of bone, the magnitudes of func-tional forces, and avoidance of neurovascular regions.

Most of the different implant designs were eventually utilized wherever edentulous regions existed. Overall, the intent was to provide a stable, functional, and aesthetic dentition. Access to the oral regions and the number of teeth per individual (up to 32) resulted in larger numbers of dental implants compared to other types (hips, knees, etc.) of implant-based treatments for musculoskeletal disorders.

To define the bone anatomies, dentists in the earlier periods utilized radiographic imaging procedures that were normally available for the evaluation of teeth and supporting bone. Periapical (zone) radiographs were extended to full arch panographic images to better describe the overall bone and tooth relationships. With the advance of the science and technology of imaging, dental radiographic imaging evolved to routine use of computed tomography, with cone bean and other technologies to minimize radiation dose to the head and neck regions. This imaging has now been extended to computer-based software and hardware systems for design and manufac-ture (CAD-CAM). This approach also now extends from treatment planning, surgical guides, and abutment con-nections, to multiple types of intraoral prosthetics, and procedures for longer-term maintenance (Misch, 1999).

BIOMATERIALS

The various biomaterials used for the construction of den-tal implant systems are summarized in Tables II.5.7.1–II.5.7.4. This summary includes the nominal bulk compositions, mechanical properties, and surface condi-tions as described in national and international standards. A wide range of surface modifications have been, and continue to be, utilized for the body sections of dental implants. Many have been based on calcium phosphate compounds which are summarized in Table II.5.7.5. A review of the biomaterials and surface alterations of den-tal implant systems shows the wide range of surface con-ditions that continue to be preferred by the profession. To simplify these considerations, the surface modifications have been categorized as those that subtract or add mass to the substrate. More details on bulk and surface char-acteristics will be included in the next section. Multiple articles and books, again, exist about the relative merits of different biomaterials and surface modifications.

FIGURE II.5.7.6 Radiograph of Root-Form Implants Supporting Intraoral Bridge Reconstructions.


TaBLE I I .5.7.2 Engineering Properties of Some Inert Ceramics Used as Biomaterials*

Material Modulus of Elasticity GN/m2 (psi μ 106) Ultimate Bending Strength Mpa (ksi) Surface

Aluminum oxidePolycrystalline 372 (54) 300–550 (43–80) Al2O3Single crystal (sapphire) 392 (56) 640 (93) Al2O3

Zirconium oxide zirconia (PSZ) 195–210 (28–30) 500–650 (72–94) ZrO2Titanium oxide (titania) 280 (41) 69–103 (10–15) TiO2

GN/m2, Giganewton per meter squared; psi, pounds per inch squared; MPa, megapascal; ksi, thousand pounds per inch squared.*These high ceramics have 0% permanent elongation at fracture.

TaBLE I I .5.7.3 Engineering Properties of Bioactive and Biodegradable Ceramics*

Material Modulus of Elasticity Gpa (psi μ 106) Ultimate Bending Strength Mpa (ksi) Surface

Hydroxyapatite 40–120 (6–17) 40–300 (6–43) Ca10(PO4)6(OH)2Tricalcium phosphate 30–120 (4–17) 15–120 (2–17) Ca3(PO4)2Bioglass or Ceravital 40–140 (6–20) 20–350 (3–51) CaPO4AW ceramic 124 (18) 213 (31) CaPO4 + FCarbon 25–40 (4–6) 150–250 (22–36) CCarbon–silicon (LTI) 25–40 (4–6) 200–700 (29–101) CSi

GPa, Gigapascal; psi, pounds per inch squared; MPa, megapascal; ksi, thousand pounds per inch squared; LTI, low-temperature isotropic.*These ceramics and carbons have 0% permanent elongation at fracture.

TaBLE I I .5.7.4 Engineering Properties of Polymers (Some Medical Grades)*

Material Modulus of Elasticity Gpa (psi μ 105) Ultimate Tensile Strength Mpa (ksi) Elongation to Fracture (%)

PTFE 0.5–3 (0.07–4.3) 17–28 (2.5–4) 200–600PET 3 (4.3) 55 (8) 50–300PMMA 3 (4.3) 69 (10) 2–15PE 8 (1.2) 48 (7) 400–500PP 9 (1.3) 35 (5) 500–700PSF 3.5 (5) 69 (10) 20–100SR 0.1 (0.014) 5 (1.1) 300–900POM 3 (4.3) 70 (10.1) 10–75

GPa, Gigapascal; psi, pounds per inch squared; MPa, megapascal; ksi, thousand pounds per inch squared; PTFE, polytetrafluoroethylene; PET, polyethylene terephthal-ate; PMMA, polymethylmethacrylate; PE, polyethylene; PP, polypropylene; PSF, polysulfone; SR, silicone rubber; POM, polyoxymethylene (IME, intra mobile element).*Polymer properties exhibit a wide range depending on processing and structure. These values have been taken from general tables.

TaBLE I I .5.7.1 Engineering Properties of Metals and Alloys Used for Surgical Implants*

MaterialNominal analysis (w/o)

Modulus of Elasticity GN/m2 (psi μ 106)

Ultimate Tensile Strength MN/m2 (ksi)

Elongation to Fracture (%) Surface

Titanium 99+Ti 97 (14) 240–550 (25–70) >15 Ti oxideTitanium–aluminum–

vanadium90Ti–6Al–4V 117 (17) 869–896 (125–130) >12 Ti oxide

Cobalt–chromium– molybdenum (casting)

66Co–27Cr–7Mo 235 (34) 655 (95) >8 Cr oxide

Stainless steel (316L) 70Fe–18Cr–12Ni 193 (28) 480–1000 (70–145) >30 Cr oxideZirconium 99+Zr 97 (14) 552 (80) 20 Zr oxideTantalum 99+Ta — 690 (100) 11 Ta oxideGold 99+Au 97 (14) 207–310 (30–45) >30 AuPlatinum 99+Pt 166 (24) 131 (19) 40 Pt

GN/m2, Giganewton per meter squared; ksi, thousand pounds per inch squared; MN/m2, meganewton per meter squared; psi, pounds per inch squared; w/o, weight percent.*Minimum values from the American Society for Testing and Materials Committee F4 documents are provided. Selected products provide a range of properties.


TISSUE INTEGRATION: BIOMATERIAL AND BIOMECHANICAL ASPECTS

The science, technology, and clinical development of sur-gical implant-to-bone integration has for decades been a central area of emphasis (Misch, 1999; Rizzo, 1988). Practical aspects of the inability to physically separate bone-to-implant interfaces for ceramic and metallic oxide implant interfaces led to considerable interest in why this occurred, and thereby to many basic and applied studies. One part of these studies was based on element and force transfers for conditions of stable in vivo function. Dental implant treatments, over four decades have, in part, con-tributed to a major change in the philosophy of dental implant-based treatments for replacement of tooth loss. From a historical perspective, early reports of tissue inte-gration for dental implants, in general, were complicated by the factors of clinical placement and restoration. Most implants were placed under variable conditions, and were immediately (hours to weeks) subjected to bio-mechanical function. Immediate intraoral restoration resulted in force transfers (stresses and strains) between the implant body and the supporting tissues during the period of initial tissue healing. Therefore, this discussion of tissue integration of dental implants will include both material and mechanical aspects of device function.

Experience prior to 1960 for a wide range of materi-als showed implant-to-tissue regions, where significant higher magnitude loads were transferred, that were fibrous soft tissue (scar-like) interfaces (James and Keller, 1974; James, 1983; Weiss, 1986). These zones were rela-tively dense collagenous structures that contained limited numbers of cells and blood vessels. Dental implants fabri-cated from steel, gold, platinum, and cobalt alloys, upon review of tissue interfaces after months to years of clini-cal function, showed soft tissue scar-like zones of contact (Lemons, 1999). In contrast, early experience with some dental implants fabricated from higher purity aluminum oxides (alumina and sapphire forms), carbons, calcium phosphate compounds, and reactive group metals and alloys (primarily titanium in the 1960s) demonstrated a mixture of direct bone-to-implant contact and soft tis-sues when evaluated histologically by optical microscopy methods. These interfacial conditions were described as

osseo- or osteo-integrated and special conditions to rou-tinely achieve these conditions were developed (Rizzo, 1988). A central focus developed for analyses of tita-nium, with oxidized surfaces contiguous with endosteal regions of oral bones. Multiple journal articles, books, conference proceedings, etc., described these and other conditions of tissue integration (Misch, 1999).

Several central conditions were defined, i.e., bulk and surface conditions for synthetic biomaterials that did not elicit a foreign-body response; surgical procedures to minimally traumatize the surgical site; and functional stresses and strains at the implant-to-bone interface where biomechanical microstrains were within the phys-iological limits of the bone during healing and longer-term function.

Considering these conditions, multiple requirements were developed for all levels of implant devices includ-ing diagnosis, surgery, restoration, and maintenance of dental implants. Analysis of the interface zone at nano-, micro-, and macrolevels of resolution demonstrated the importance of careful control of implant bulk and surface properties, and cleanliness, surgical methods and site dimensions, times and conditions of intraoral abutment placement, intraoral restoration, and main-tenance (cleaning) of the percutaneous transition zone. As an example, of biomaterial properties, if unit area of implant, bone, and force were modeled, the interfacial strain magnitude would depend directly on any applied forces (the force vector direction and magnitude), the smoothness/roughness of the contact zone, attachment (bonding), and the elastic moduli of the implant bioma-terial and the bone. Limited attachment (bonding) has been shown for some bioactive surfaces (e.g., calcium phosphates, glasses, etc.); however, most ceramics such as alumina, zirconia, and titania, and most surface oxi-dized metallics have demonstrated contact, but minimal or no chemical-type bonding. Most have reported that chromium oxides found on iron and cobalt alloys related to passivation were separated from the bone by a zone of non-osseous (fibrous) tissue. Surface roughness (irreg-ularities) were shown to provide conditions for inter-digitation under conditions of microscopic contact with mineralized bone, and microscopic regions of force trans-fer, plus potential advances for early healing (depositions

TaBLE I I .5.7.5 Names, Formulae, and Atomic Ratios for Some Calcium Phosphate Materials

Mineral or General Name Formula Ca:p ratio applications

Monetite (DVP) CaHPO4 1 Nonceramic bone substitute particulateBrushite (DCPD) CaHPO4 2H2O 1 Phase of some CaPO4 biomaterialsOctacalcium phosphate (OCP) Ca8(HPO4)2(PO4) 5H2O 1.33 Phase of some CaPO4 biomaterialsWhitlockite (WH) Ca10(HPO4)(PO4)6 1.43 Phase of some CaPO4 biomaterialsBeta-tricalcium phosphate (b-TCP) Ca3(PO4)2 1.48 Biodegradable CaPO4 ceramic for bone substitute and

coatings; also a phase of some CaPO4 biomaterialsDefective hydroxyapatite (DOHA) biomaterials Ca9(HPO4)(PO4)5(OH) 1.5 Component of some CaPO4 biomaterialsHydroxyapatite (HA) Ca10(PO4)6(OH)2 1.67 Major mineral phase of bone; when fired as a ceramic,

named HA


of blood clot, fibrin, integrins, etc.) Microtopography was proposed to be critical for conditions of loading as a resistance to microscopic shear at the interface.

Returning to the role of implant and tissue moduli, conditions of unit area and force led to a method for eval-uating relative strain magnitudes at the interfacial zone. If the interface is non-interdigitated and non-chemically bonded, strain magnitudes of the contact zone for each part would be proportional to the elastic modulus of each part. On a comparative basis of the biomaterial relative to compact bone, ceramics of alumina and zirconia have moduli of more than 10×, alloys 5–10×, with unalloyed titanium the lower magnitude, carbon and calcium phos-phates about 0.5–2×, and polymerics lower by 50–1000× difference. The polymerics in general have moduli that are more similar to soft tissues. Clearly, the overall mac-roscopic shape, size, and geometry of the implant, the implant biomaterial and surface, the macro- and micro-anatomy of the bone, and the clinical conditions of func-tion have been shown to directly influence the specific properties and conditions at the device interface. In this regard, dental implants over the years have included a very wide range of the circumstances listed above. How-ever, in general, longer-term bone integration has been shown for implants fabricated from ceramic and metallic biomaterials which have included a range of physical fea-tures (macro- and microgeometries, microtopographies over a range of micro-dimensions and shapes often clas-sified as pins, rods, screws, finns, plates, etc.) with and without surface modifications.

Implant survival statistics support high percentages (above 90%) remaining functional for decades. In the 2010s dental implants are expanding as a treatment of choice; where a tooth is lost, an implant is placed. Many propose this as the best and most cost-efficient way to maintain dental health over the longer-term. Therefore, the demand for dental implant treatments in society at large has increased, and the professional society and dental school programs are now offering basic education and training at the dental medicine (DMD) undergraduate level. These treatments have evolved to a “standard of care” status.

Many different implant biomaterials and designs have been studied; however, the larger numbers of appli-cations have now become root-form designs placed, restored, and maintained for function through osteoin-tegrated interfaces with bone. The biomaterials are now mostly titanium and alloys with a wide range of surface modifications for influencing interfacial tissue regions. Surface modifications include compositional (primarily oxides, calcium phosphates, and fluoride) and micro-topographical features (degrees of roughness). These concepts also extend to the gingival and mucosal soft tissue to implant interfacial systems.

Interest has also been ever increasing in the use of synthetic-active biologic combinations for enhancing tis-sue quantity, quality, and healing characteristics. Many dentists now restore the dental implants to limited func-tional use immediately after surgical placement. Some call this “back to the future.” Research and development at many levels supports possibilities for hard and soft tissue and tooth regeneration through tissue-engineered regenerative medicine approaches. If accomplished, the need for current dental implants based on synthetic bio-materials may be decreased accordingly. Most say that considerable science needs to be completed to accomplish the regeneration of anatomical replicates of functional and healthy teeth. Early research is most promising, and rapid advancements in regenerative approaches are anticipated.

BIBLIOGRAPHY

Baker, M., Eberhardt, A., Martin, D. M., McGuin, G., & Lemons, J. (2010). Bone Properties Surrounding Hydroxyapatite-Coated Custom Osseous Integrated Dental Implants. J. Biomed. Mater. Res., 95B, 218–224.

Branemark, P. I., Hanssen, B. O., Adell, R., Brien, U., Lindstrom, J., et al. (1977). Osseointegrated implants in the treatment of the edentulous jaw. Scand. J. Plast. Reconstr. Surg. (Suppl. 16).

Cranin, A. N. (1970). Some philosophic comments on the endos-teal implant. Dent. Clin. N. Am., 14, 173–175.

James, R. A. (1983). Subperiosteal implant designs based on peri-implant tissue behavior. NY J. Dent., 53, 407.

James, R. A., & Keller, E. E. (1974). A histopathological report on the nature of the epithelium and underlying connective tis-sue which surrounds oral implants. J. Biomed. Mater. Res., 8, 373–383.

Lemons, J. (1999). Biomaterials for Dental Implants, In: Misch, C.E. (Ed.). Contemporary Implant Dentistry, 3e, Mosby Elsevier, St. Louis, MA, Ch24.

Meffert, R. M., Langer, B., & Fritz, M. E. (1992). Dental implants: A review. J. Periodental., 63, 859–870.

Misch, C. E. (1999). Contemporary Implant Dentistry (2nd ed.). St. Louis, IL: Mosby. 94–106.

Rizzo, A. A., (1988). Proceedings of the 1988 Consensus Devel-opment Conference on Dental Implants. J. Dent. Educ., 52, 678–827.

Roberts, H. D., & Roberts, R. A. (1970). The ramus endosseous implant. J. S. Calif. Dent. Assoc., 38, 571.

Schnitman, P. A. (1987). Diagnosis, treatment planning, and the sequencing of treatment for implant reconstructive procedures. Alpha Omegan, 80, 32.

Small, I. A. (1980). Benefit and risk of mandibular staple bone-plates. In Dental Implants: Benefit and Risk (pp. 139–152). Washington, DC: US Public Health Service. PHS Pub. 81–1531.

Strock, A. E. (1939). Experimental work on direct implantation in the alveolus. Am. J. Orthol. Oral. Surg., 25, 5.

Weiss, C. M. (1986). Tissue integration of dental endosseous implants: Description and comparative analysis of fibro-osseous integration and osseous integration systems. J. Oral. Implantol., 12, 169.

biomaterials science || dental implantation

Documents