Implants sites with concomitant bone regeneration using a resorbable or non-resorbable membrane result in stable marginal bone levels and similar profilometric outcomes over 5 years.

OBJECTIVES To assess clinical and radiographic outcomes as well as the profilometric contour alterations of peri-implant hard and soft tissues around single implants treated with simultaneous guided bone regeneration (GBR) at 5 years. MATERIALS AND METHODS Twenty-seven patients presenting with a single tooth gap in the esthetic zone received a two-piece implant. GBR was randomly performed using a resorbable (RES) or a non-resorbable membrane (N-RES) combined with a bone substitute material. Follow-up examinations were performed at baseline (BL=crown insertion), 1 year (FU-1), 3 years (FU-3) and at 5 years (FU-5) including clinical and radiographic parameters as well as profilometric changes. Statistics were performed by means of parametric and nonparametric tests. RESULTS At 5 years, 20 out of 27 patients (9 RES, 11 N-RES) were re-examined. Median values for probing depth changed insignificantly between BL and FU-5 in both groups. The median marginal bone levels were located 0.23mm (0.06; 0.46; RES) and 0.17mm (0.13;0.28; N-RES) below the implant shoulder at FU-5 (changes over time p<0.05). The calculated median profilometric change between BL and FU-5 was -0.28mm (-0.53;-0.20; RES) (p = 0.016) and -0.24mm (-0.43;0.08; N-RES) (p=0.102) (intergroup p=0.380). The horizontal bone thickness decreased significantly between re-entry and FU-5 for group RES at all measured levels (p<0.05 ) measuring 0.87mm (0.0;2.05) at the implant shoulder, whereas the decrease for group N-RES was insignificant (p=0.031) with 0mm (0; 0.84) at the implant shoulder at 5 years. CONCLUSIONS Implants sites with concomitant GBR using a resorbable or non-resorbable membrane revealed stable marginal bone levels and clinical outcomes. Profilometric changes were clinically negligible over 5 years. The observed change in hard tissue thickness was partially compensated by an increase in soft tissue thickness.