Periimplant defect grafting with autogenous bone or bone graft material in immediate implants placement in molar extraction sites First results of a prospective randomized study

The aim of this prospective study is to evaluate the survival rate and stability of periimplant hard and soft tissue following immediate implant placement of Astra Tech OsseoSpeed EV 5,4S implants in molar extraction sites and periimplant defect grafting with autogenous bone or alloplastic bone graft material. Material and methods: 50 implants were inserted. The periimplant defect augmentation was performed randomized with either autogenous bone (AK) or with a biphasic bone graft material (Symbios) (SY). Primary outcome variable was implant survival, secondary outcome variables were marginal bone level changes, orobuccal width of the alveolar crest, periimplant probing depths and implant success. Results: One implant of the SY group was lost. 49 patients were followed in average for 14 months. Survival rate was 100 % in the AK and 96 % in the SY group. Interproximal bone level regenerated from -7,5 mm to -0,3 mm apical of the implant shoulder at final follow-up. The width of the alveolar crest changed by -0.9 mm (AK) and +0.3 mm (SY) 1 mm apical to implant shoulder, -1.1 mm (AK) and +0.2 mm (SY) 3 mm apical, -0.8 mm (AK) and +0.6 mm (SY) 6 mm apical to this level. 8 implants (3 AK, 5 SY) showed a decrease of the interproximal marginal bone to more than 1 mm or probing depth more than 5 mm. Conclusion: First results prove a high survival rate, a favorable defect regeneration and a low amount of orobuccal resorption in immediate molar implant insertion without differences for the bone graft material.