Effect of ridge preservation for early implant placement - is there a need to remove the biomaterial?

Abstract

AIM To assess (i) bone regeneration around implants placed early in sites with or without ridge preservation and (ii) if the bone substitute material (DBBM-C) has to be removed at implant placement. MATERIALS AND METHODS In eight beagle dogs, three sites were randomly assigned to ridge preservation (DBBM-C plus collagen matrix (CMX)) (two sites; RP) or spontaneous healing (1 site; SH). Four weeks later, in one of the RP sites, dental implants were placed without removing the DBBM-C (RP1), whereas in RP2 and SH sites all non-integrated DBBM-C and/or granulation tissue were removed before implant placement and concomitant GBR. Histomorphometric outcomes were assessed at 4 and 12 weeks. RESULTS The median buccal fBIC (first bone-to-implant contact) was located more apical in groups RP1: 1.34 mm (0.09; 2.96) and RP2: 1.41 mm (0.54; 2.72) than in group SH: 0.79 mm (0.26; 1.50) (p = 0.452) at 4 weeks. At 12 weeks, median buccal fBIC values were for RP1: 0.88 mm (0.00; 2.33), for RP2: 0.16 mm (0.00; 1.33) and for SH: 0.00 mm (0.00; 0.98) (p = 0.362). BIC values increased over 12 weeks in all groups. CONCLUSIONS Ridge preservation followed by early implant placement led to higher BIC values at 12 than at 4 weeks. There is no need to remove the biomaterial at implant placement to ensure osseointegration. No relevant differences were observed between the three groups for any outcome measure.