In this paper, the biocompatibility of dental implant materials is discussed in the context of both the mechanical characteristics of the materials and the type of surface presented to the surrounding tissues. The proper functioning of the implant depends on whether it possesses the strength necessary to withstand loading within the expected range, with other properties such as elongation being of importance in some instances. A suitable modulus of elasticity may be of major importance in situations when optimum load transmission from the implant into the surrounding bone is key to the successful functioning of the device. Dental implants present a wide range of surfaces to the surrounding tissues based on surface composition, texture, charge energy, and cleanliness (sterility). Metallic implants are characterized by protective oxide layers, but ion release is still common with these materials, and is a function of passivation state, composition, and corrosion potential. An effective surface treatment for titanium appears to be passivation or anodization in a suitable solution prior to implantation. Inert ceramic surfaces exhibit minimal ion release, but are similar to metals in that they do not form a high energy bond to the surrounding bone. Some of the newly developed dental implant alloys such as titanium alloys, which contain zirconium and niobium, and high-strength ceramics such as zirconia may offer some advantages (such as lower modulus of elasticity) over the conventional materials. Calcium phosphate ceramic coatings are commonly used to convert metallic surfaces into a more bioactive state and typically cause faster bone apposition. There is a wide range of ceramic coatings containing calcium and phosphorus, with the primary difference in many of these materials being in the rate of ion release. Although their long-term success rate is unknown, the calcium phosphate surfaces seem to have a higher potential for attachment of osteoinductive agents than do uncoated titanium and other more inert implant materials.
[1]
C. Klein,et al.
Behavior of calcium phosphate coatings with different chemistries in bone.
,
1996,
The International journal of prosthodontics.
[2]
T. Yamamuro,et al.
Bone-bonding behavior under load-bearing conditions of an alumina ceramic implant incorporating beads coated with glass-ceramic containing apatite and wollastonite.
,
1995,
Journal of biomedical materials research.
[3]
J. Davidson,et al.
Mechanical and Tribological Properties and Biocompatibility of Diffusion Hardened Ti-13Nb-13Zr — A New Titanium Alloy for Surgical Implants
,
1996
.
[4]
S. Downes,et al.
Comparison of the release of growth hormone from hydroxyapatite, heat-treated hydroxyapatite, and fluoroapatite coatings on titanium.
,
1995,
Journal of biomedical materials research.
[5]
C. Bünger,et al.
Transforming growth factor-beta stimulates bone ongrowth. Hydroxyapatite-coated implants studied in dogs.
,
1996,
Acta orthopaedica Scandinavica.
[6]
R. Venugopalan,et al.
Evaluation of restorative and implant alloys galvanically coupled to titanium.
,
1998,
Dental materials : official publication of the Academy of Dental Materials.
[7]
Y. Okazaki,et al.
New Titanium Alloys to be Considered for Medical Implants
,
1996
.
[8]
C. V. van Blitterswijk,et al.
Bone-bonding behaviour of poly(ethylene oxide)-polybutylene terephthalate copolymer coatings and bulk implants: a comparative study.
,
1995,
Biomaterials.