Analysis of bone dimensional stability after two-stage maxillary sinus floor augmentation with autogenous bone versus bovine bone mineral combined with autogenous bone chips: results from a 1-year multicenter split-mouth randomized controlled trial

Abstract

Objective: To compare the dimensional stability of augmented bone following maxillary sinus floor augmentation (MSFA) using autogenous bone (AB) alone or bovine bone mineral combined with locally harvested AB chips (BBM), one year after implant loading.

Material and methods: A secondary analysis of a split-mouth, multicenter randomized controlled trial was conducted among 20 patients (40 implants). CBCT/CTs were used to measure bone height (buccal and palatal aspects) and bone area at the implant center at two time points: before implant placement (4-6 months post-MSFA, T1) and 12 months post-implant loading (T2). Residual bone height and sinus width at 1, 5, and 10 mm from the crest were also recorded. Linear regression models with generalized estimating equations were used to assess the influence of graft material (AB and BBM), initial graft dimensions and sinus width on dimensional changes.

Results: Adjusted regression models showed that AB-treated sites experienced significantly greater reductions in graft height (mean difference at buccal sites: -1.76 mm [95 % CI, -0.86 to -2.65]; p-value = <0.001); mean difference at palatal sites: -1.82 mm [95 % CI -0.75 to -2.88]; p = 0.001; and bone area (mean difference -17.80 mm² [95 % CI -6.61 to -28.99]; p = 0.002) compared to BBM. Greater initial graft height and area were associated with reduced dimensional changes (p < 0.001) especially when using BBM. Sinus width, measured 10 mm from the crest, was modestly but significantly associated with changes in bone height (p = 0.020), but not with changes in bone area (p = 0.147).

Conclusion: MSFA using BBM combined with autogenous bone chips resulted in greater dimensional stability compared to AB alone.

Clinical implications: BBM combined with autogenous bone chips better preserved graft dimensions than AB alone.

Keywords: Autogenous bone; Bovine bone mineral; Cone beam computed tomography; Maxillary sinus floor augmentation; Randomized controlled trial.