Centre versus peripheral tapping during lateral window sinus lift preparation: an ex vivo comparative study

Aim: To compare centre and peripheral tapping techniques during lateral window sinus lift preparation with respect to residual peripheral bone rim thickness and the frequency of Schneiderian membrane perforation in an ex vivo goat maxilla model. Methods: Twenty goat maxillary specimens were evaluated, with both contralateral sides used, yielding 40 lateral-window preparations arranged as 20 matched pairs. One side of each specimen underwent centre tapping, and the contralateral side underwent peripheral tapping. Residual peripheral bone rim thickness was measured at six predefined locations following window mobilization, and Schneiderian membrane perforation was recorded as present or absent. Residual bone-rim thickness was summarized as mean ± standard deviation (SD) from the available measurements, while membrane perforation was evaluated descriptively. Results: Peripheral tapping demonstrated greater mean residual peripheral bone rim thickness than centre tapping at all six measurement sites. Based on recalculation from the available group-level summary data, significant differences were observed at the superio-anterior (0.26 ± 0.02 mm vs. 0.14 ± 0.01 mm; p < 0.001), superior (0.27 ± 0.01 mm vs. 0.24 ± 0.01 mm; p < 0.001), superio-posterior (0.12 ± 0.02 mm vs. 0.10 ± 0.02 mm; p = 0.007), inferior (0.13 ± 0.02 mm vs. 0.09 ± 0.02 mm; p < 0.001), and inferio-anterior (0.19 ± 0.02 mm vs. 0.09 ± 0.02 mm; p < 0.001) regions. The inferio-posterior difference was not statistically significant (0.13 ± 0.01 mm vs. 0.12 ± 0.02 mm; p = 0.165). Schneiderian membrane perforation was observed in 8/20 (40.0%) centre-tapping preparations and 4/20 (20.0%) peripheral-tapping preparations. Conclusions: Peripheral tapping was associated with greater residual peripheral bone-rim thickness at most evaluated sites and a numerically lower observed frequency of Schneiderian membrane perforation than centre tapping. The findings support peripheral tapping as a promising favourable technical profile that merits further paired experimental evaluation.