Bone volume changes after immediate implant placement with or without flap elevation.

Abstract

The placement of implants immediately after tooth extraction is the ideal treatment option in selected cases. However, previous studies have shown that placing an implant does not avoid the shrinkage of the alveolar ridge. The aims of the present investigation were to evaluate bone dimensions after immediate implant placement with simultaneous grafting of the buccal gap, to determine if initial buccal bone width had an influence on bone remodelling and to compare bone volume changes using a flap or a flapless approach after 6 months of healing. Material and methods This prospective study included patients who required an extraction and a subsequent immediate implant placement at a non-molar site. In those cases where tooth extraction was not feasible with a flapless approach (test group) a mucoperiosteal flap was carefully elevated (control group). After extraction, a cone beam computed tomography (CBCT) was taken. Then, an implant was placed and the buccal gap was grafted using anorganic bovine bone. After 6 months of healing, a second CBCT was performed. A blinded investigator superimposed both images and performed a series of measurements to determine bone volume changes between the two time points. Results Thirty-five patients were included in this study, 20 of which belonged to the test group. All together, the differences between baseline and 6 months in buccal plate height, lingual 10 plate height and in ridge width at 2, 4 and 6 mm were 0.48±1.35; 0.58±1.51; 0.64±0.81; 0.59±1.36 and 0.52±1.16 respectively. Only a moderate correlation was observed between initial buccal plate width and buccal plate height at 6 months (p=0.0001). No statistically significant differences were observed between flap and flapless approach. Conclusion A mean reduction of around 0,5mm in height and width after placing immediate implants and filling the residual gap with anorganic bovine bone may be expected. No significant association between initial buccal bone width and ridge width at 6 months was seen. No statistically significant differences were found between the two treatment protocols although more ridge reduction was observed for the flap group.