“…It could be hypothesized that this heterogeneity may be explained by the fact that some studies used antibiotics (14)(15)(16)24,25,27,29,34) and others did not (10,17,23,26,28,30,35), by the variable surface treatments, inclusion of smokers (10,(14)(15)(16)(17)(23)(24)(25)28,29,34,35), initial depth of defects and number of remaining bone walls, use of placebo gel in some studies (10,15,16,27,34) and not in others (14,17,23-26,28,29,35), differences in methodological quality, in addition to other variables that could influence the results, such as the surgical technique, quality of instrumentation and biofilm control performed by the patients (45).…”