The aim of the present study was to resume in a review the literature evaluating the incidence of sinus membrane perforation comparing conventional rotating instruments with piezoelectric devices. Since only scarce studies exist comparing both techniques directly, we decided to additionally include any study on MSA in which information on the applied technique, e.g. conventional or piezosurgery, was retrievable and additionally reporting on the incidence of membrane perforations. This procedure leads to heterogeneity of the collected data and accordingly included study designs. Obviously, a lot more studies with conventional approach than piezosurgery were included determining the incidence of membrane perforations. In order to reduce the resulting bias, forest plots were calculated and the weight was adjusted on the raw data, resulting in determination of the random effect. Another bias may affect the use of both conventional drilling for antrostomy and additionally piezosurgery for initial membrane elevation. The data were inconsistent in detailed information if combinations were used. Therefore, we decided to determine the piezosurgery group for both: single use for osteotomy and membrane elevation as well as for initial membrane elevation alone.

The present study may have a weakness, because membrane tear detection was not the primary focus and endpoint of many of our included studies. Many perforations might have been overlooked or not paid attention to this specific problem. The impact of different piezo tips on membrane perforation risk needs to be evaluated in further studies. With regard to our results, the present study showed that the weighted average incidence of perforation during MSA is 24% for rotating instruments and 8% for piezosurgery. These differences were statistically highly significant (p < 0.005). With regard to the presented results, piezosurgery can be recommended reducing the risk of membrane perforation during MSA. However, though this seems to be a reliable statement, it is not clear, whether combinations, e.g. osteotomy with rotating instruments and preparation of the membrane with piezosurgery, may be an alternative approach combining time efficiency with safety. The results suggest that piezosurgery was associated with a lower perforation rate. However, this statement is not reliable because of the inclusion of non-randomised and non-controlled studies as well as retrospective data. More RCTs focusing on membrane perforation are needed for a final conclusion.