Implant/Abutment Biomechanics and Material Selection for Predictable Results

Change in crestal bone height and volume around endosseous dental implants is a complex issue involving interactions among many variables such as surgical approach, patient health, volume of hard and soft tissues, and implant configuration. Establishing and maintaining a soft-tissue seal around transmucosal abutments on bone-level implants or on the collar of one-stage tissue-level implants is paramount to maintaining crestal bone height, and failing to do so will result in apical migration of the soft tissue onto the implant. Bone-level implants have been constructed with many connection configurations. Locking-taper conical connection implants have proven superior to buttress joint implants at achieving a tight seal and eliminating the microgap at the implant-to-abutment junction and have demonstrated improvements in crestal bone maintenance. Attaining a transmucosal seal on locking-taper conical connection implants is dependent on the use of proven tissue-compatible materials such as titanium and zirconia. Gold and dental porcelain directly to the bone-level implant has been shown to cause tissue recession and bone loss around the implant; use of these materials directly to the implant interface should be confined to one-stage tissue-level implants. Lastly, proper abutment processing and clinical handling finalize the process. Poor dental laboratory processing can lead to loss of the tight locking-taper conical connection seal and screw loosening, while clinicians must keep the abutments clean and sterile. Best practice is for clinicians to inspect all abutments upon receipt from the lab and clean them with soap and water, followed by autoclave sterilization.