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

Abstract

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 5years. 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), 1year (FU-1), 3years (FU-3), and at 5years (FU-5) including clinical and radiographic parameters as well as profilometric changes. Statistics were performed by means of parametric and nonparametric tests. At 5years, 20 out of 27 patients (9 RES, 11N-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<.05). The calculated median profilometric change between BL and FU-5 was -0.28mm (-0.53;-0.20; RES; p=.016) and -0.24mm (-0.43;0.08; N-RES; p=.102; intergroup p=.380). The horizontal bone thickness decreased significantly between re-entry and FU-5 for group RES at all measured levels (p<.05) measuring 0.87mm (0.0; 2.05) at the implant shoulder, whereas the decrease for group N-RES was insignificant (p=.031) with 0mm (0; 0.84) at the implant shoulder at 5years. 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 5years. The observed change in hard tissue thickness was partially compensated by an increase in soft tissue thickness.