Surface Modification of Dental Implants - A Review

The use of dental implants for the replacement of missing teeth has increased in the last 30 years. The success rates for implant placement depend on a series of both biological and clinical steps which starts with primary stability that is being provided by the amount, quality and the distribution of bone within the proposed implant site. The most important factor in implant osseointegration is surface roughness, which shows increased osteoblast activity at 1 to 100 mu m of the surface roughness when compared to a smooth surface. Rough surfaces have excellent osseointegration than smooth surfaces, but the results of research have been diverse, and it is evident that multiple treatments provide good results. The surfaces of a dental implant have been modified in several ways to improve its biocompatibility and speed up osseointegration. Literature says that any surface modification provides a good surface for osseointegration of the implant when the surface roughness is about 0.44 similar to 8.68 mu m. It is also said that acid etching and coating are the most preferred methods for creating good roughness of the implant surface. From animal studies, it is known that implant surface modifications provided by biomolecular coating seemed to enhance the osseointegration by promoting peri-implant bone formation in the early stages of healing. It also seemed to improve histomorphometric analysis and biomechanical testing results. This article reviews the surface modifications of dental implants for the achievement of better success rates. Various methods are used to modify the topography or the chemistry of the implant surfaces which includes acid etching, anodic oxidation, blasting, treatment with fluoride, and calcium phosphate coating. These modifications provide a faster and a stronger osseointegration.(1) Recently, hydrophilic properties added to the roughened surfaces or some osteogenic peptides coated on the surfaces shows higher biocompatibility and have induced faster osseointegration compared to the existing modified surfaces. With development in surface engineering techniques, new information on the properties, behaviour, and the reaction of various materials could be discovered which in turn allows the discovery of new materials, modification techniques and design of bio implants for the future.