SUCCESSFUL BONE-FORMATION AT IMMEDIATE TRANSMUCOSAL IMPLANTS - A CLINICAL REPORT

The aim of this study was to test whether bone could be formed in peri -implant defects at immediate transmucosal implants using guided bone regeneration. Ten patients (median age 48 years) underwent comprehensi ve dental care including the placement of an implant into an extractio n socket immediately following removal of a tooth. An expanded polytet rafluoroethylene membrane and the mucoperiosteal flap were adapted aro und the neck of the implants, leaving the sites to heal in a transmuco sal fashion. During implantation (baseline) and at membrane removal su rgery 5 months later, the following clinical measurements from the imp lant shoulder were assessed at six sites: implant-bone contact (defect depth), level of the alveolar crest, level of the membrane, and dista nce from the crest to the implant body (defect width). Estimates of th e defect volume bordered by the membrane, the implant, and the bony wa lls were calculated. At baseline, the mean defect depth was 4.7 mm (SD 1.3 mm, range 1 to 14 mm). At membrane removal, the mean defect depth had decreased to 2.1 mm (SD 0.8 mm). Compared to baseline, this decre ase was statistically significant (P <.01). The mean increase in bone height at the deepest defect site of each implant was 6.7 mm (SD 3.0 m m), which was significant (P <.01). At baseline, the mean value for th e defect volume estimates was 9.45 mm(3) (SD 5.75 mm(3)). At membrane removal, a significant decrease (P <.01) was found. After 5 months, 94 % of the area beneath the membrane was filled with new bone. It was co ncluded that guided tissue regeneration at immediate transmucosal impl ants is successful in generating bone into peri-implant defects.