Periodontal considerations in restorative and implant therapy.

The successful integration of periodontal and restorative dentistry for both natural teeth and implants requires knowledge and application of both mechanical and biological principles. In areas of aesthetic concern, an adequate band of attached gingiva can increase patient comfort, reduce the probability of gingival recession following tooth preparation and simplify restorative procedures. While some restorative margins need to be placed at or below the margin of the free gingiva, this should be considered to be a compromise, and margins should not be placed more than 0.5 mm into a healthy gingival sulcus. Approximately 2-3 mm of healthy, natural supra-alveolar tooth surface is needed for attachment of the gingival tissues to the tooth. This dimension is called the biological width. If adequate biological width does not exist, surgical or orthodontic procedures to expose healthy tooth structure are recommended before final restorations are placed. Retraction of soft tissues for impressions is best accomplished with mechanical methods rather than lasers or electrosurgery because of the potentially harmful effects of these devices to the cementum, bone and soft tissues surrounding the teeth. Implants function best and withstand occlusal forces optimally when loaded in a vertical direction. Therefore, planning implant placement is critical for success. Because of increased proprioception, it is suggested that natural teeth be used to guide the occlusion in partially edentulous patients. Cantilevers should be used with caution and with appropriate attention to occlusal forces. While occlusal trauma does not cause periodontal disease, it may contribute to bone loss around teeth and implants. In the opinion of the authors, provisional restorations are an integral part of dental and periodontal therapy. They can be used to establish aesthetic and physiological contours that can be easily cleaned by patients and they can also be used as a guide for any needed surgical tissue modification.