DISCUSSION
trauma
SECONDARY, RECRUITMENT, INFLAMMATORY RESPONSE
This multi‐center randomized clinical trial aims to compare primary and secondary stability of implants inserted into sites prepared with OD and piezoelectric tips. Being the very first analysis comparing OD and PISP, it was possible to examine and discuss only the available evidence on OD and PISP resulting from studies in which conventional drilling was used as comparator.The present study was designed to control variables influencing implant primary stability, in order to highlight the impact of surgical technique on the healing process.Primary stability was not significantly different between the test and control group either in terms of peak insertion torque (40.7 ± 12.3 Ncm in test group and 39.5 ± 10.2 Ncm in control group) or in ISQ (71.3 ± 6.9 and 69.3 ± 7.6 in test and control group, respectively). This outcome is indirectly confirmed by numerous studies on human subjects showing no significant difference in primary stability between implants inserted after conventional drilling when compared with PISP.In the context of the inflammatory response to surgical trauma, bone microdamage induces peri‐implant bone remodeling with definite steps (activation of osteoclast cutting cones, damaged bone removal by osteoclasts, pericytes recruitment and their differentiation into osteoblasts, and new bone formation by these osteoblasts).After 12 months of prosthetic loading, 53 out of 54 implants were satisfactorily in function. One implant failed in the OD group before loading (1/27; 96.2% survival rate), while no failures were recorded in the PISP group (0/27; 100% survival rate). Also for this outcome, no significant differences were demonstrated between the two groups, in accordance with previous clinical studies and meta‐analyses reporting similar survival rates for implants inserted with different implant site preparation techniques.It must be underlined that the findings of this multi‐center randomized clinical trial should be interpreted with caution due to some limitations of the present study. Factors including the limited numerosity of the sample, the selection of a specific surgical site (only lateral maxilla) and the use of a single implant type should be taken into consideration when generalizing the present results.After analyzing data from the present study, it was not possible to reject the null hypothesis of this trial. In other words, no significant differences in implant stability were demonstrated between implants inserted into sites prepared with OD or piezoelectric surgery. Further, well‐designed preclinical studies and additional clinical trials are needed to better clarify the bone healing process after osseodensification procedures, and the possible benefits of this approach for dental implant therapy in low density bone.