A Randomized Controlled Trial Evaluating the Impact of Sinus Membrane Thickness and Sinus Dimensions on the Effectiveness of Two Graft Materials in Sinus Bone Augmentation

Though sinus floor augmentation surgery has been a well-established treatment modality for bone augmentation in the posterior maxilla, the effect of sinus membrane inflammation and sinus dimensions on graft maturation has not been elucidated. The purpose of this study was to evaluate the impact of sinus membrane thickness and sinus dimensions on the effectiveness of two graft materials—demineralized freeze-dried bone (DFDB) and bovine bone graft in sinus bone augmentation.

Twenty patients requiring sinus floor augmentation surgery who had residual bone height less than 4 mm and ridge width of at least 5 mm were included in this randomized control study. All patients underwent a preoperative CBCT to determine the following—residual bone height, sinus width at a distance of 15 mm from the residual sinus floor, and the sinus membrane thickness. A two-stage procedure was opted for all the patients. Direct sinus lift was performed using the lateral window technique. Once the sinus membrane was lifted, patients were randomly allocated to one of the two groups, Group A—DFDB and Group B—Bovine bone graft. The second stage procedure of dental implant placement was carried out after six months.

A statistically significant difference (p = .009) was seen between the groups for an average loss of bone graft by resorption. The mean was 4.38 mm ± 2.877 in Group A, and 1.58 ± 0.945 in Group B. Also, the bone height gained after 6 months in groups A and B was 8.52 mm ± 2.99 and 11.42 mm ± 0.94, respectively (p = .009).

Further, on subgroup analysis, the mean graft resorption was 7.45 mm ± 1.593 when sinus membrane thickness was > 5 mm and it was 2.33 mm ± 0.903 when the membrane thickness was < 5 mm in Group A (p = .001). No statistically significant association could be derived for Group B in terms of immediate height gain, and mean bone loss for the sinus width and sinus membrane thickness variables, respectively.

The average sinus width and sinus membrane thickness < 5 mm provide favorable anatomy for achieving acceptable bone height and lesser resorption after grafting with DFDB. However, when sinus membrane thickness is > 5 mm, bovine bone graft provides more predictable results.