Peri-implant defect grafting with autogenous bone or bone graft material in immediate implant placement in molar extraction sites-1- to 3-year results of a prospective randomized study

Objectives: To evaluate the survival rate, the orobuccal bone resorption and stability of peri-implant hard and soft tissues following immediate implant placement of wide diameter implants in molar extraction sites and peri-implant defect grafting with autogenous bone (AB) or biphasic bone graft material (BBGM) with 1- to 3-year follow-up examinations.

Material and methods: Fifty wide diameter implants were placed in 50 patients immediately into molar extraction sockets by a flapless approach. Peri-implant defect augmentation was performed randomized with either AB or BBGM. Primary outcome variable was implant survival. Marginal bone level changes, orobuccal width of the alveolar crest, probing depths, and implant success were considered as secondary parameters.

Results: One implant of the BBGM group was lost, 1 patient withdrew from the study (drop-out). The remaining 48 patients were still in function at a follow-up period up to 31 months after implant insertion. Interproximal marginal bone level regenerated from -7.5 mm to the level of the implant shoulder (AB + 0.38 mm, BBGM + 0.1 mm) at final follow-up. The width of the alveolar crest changed by -0.08 mm (AB) and +0.72 mm (BBGM) at 1 mm, -0.36 mm (AB) and +0.27 mm (BBGM) at 3 mm, -0.36 mm (AB) and +0.31 mm (BBGM) at 6 mm apical to implant shoulder level. Success rate was 87.5% in the AB and 56.3% in the BBGM group (p = .058).

Conclusions: Medium-term results prove a high survival rate, a favorable amount of bone generation in both groups and a low amount of orobuccal resorption in immediate molar implant insertion.