Long-term outcome of implants placed with guided bone regeneration (GBR) using resorbable and non-resorbable membranes after 12-14 years.

AIM The aim of the present prospective study was to evaluate the long-term outcome of implants placed simultaneously with guided bone regeneration (GBR) using resorbable and non-resorbable membranes. MATERIALS AND METHODS The original study population consisted of 72 patients receiving a total of 265 implants. In all GBR-treated sites, demineralized bovine bone mineral (DBBM) was used in combination either with a collagen (CM) or an Expanded polytetrafluoroethylene (e-PTFE) membrane. A total of 112 implants was treated with CM, 41 implants were treated with e-PTFE membranes, and 112 served as a control group because implants were entirely surrounded by bone and did not need any GBR procedures. Clinical and radiographic analyses were performed after a period of 12-14 years. RESULTS The median follow-up time was 12.5 years (range 12-14 years). A total of 58 patients participated in the present investigation, corresponding to 80.5% of the original study population. The cumulative implant survival rate at the follow-up examination was 93.2%. For the control group the cumulative survival rate was 94.6%, for the CM 91.9%, and for the e-PTFE 92.6%. Differences among the groups were not statistically significant. The radiographically determined marginal bone level (MBL) amounted to: control 2.36 mm (SD), CM 2.4 mm (SD), e-PTFE 2.53 mm (SD). There is no evidence (P < 0.2) that the slope of bone level over time is different for the three treatment groups. CONCLUSION It is concluded that implants placed simultaneously with GBR procedures using resorbable or non-resorbable membranes reveal a high survival rate ranging from 91.9% to 92.6%, therefore it is considered to be a safe and predictable therapy. [Correction added after online publication 30 November 2012: the marginal bone level of CM, e-PTFE, and control was corrected to 'control 2.36 mm (SD), CM 2.4 mm (SD), e-PTFE 2.53 mm (SD)' in the Results section].