Background: The risk of periodontal defects after the extraction of third molars continues to challenge clinicians. Methods: Intervention trials, including subgingival scaling and/or root planing, were systematically reviewed. Data sources included the Cochrane Oral Health Group Trials Register and MEDLINE. The primary outcome was postoperative change in pocket probing depth (PD). Results: The electronic search yielded 751 abstracts, and manual searching added one study. From them, four trials fulfilled the inclusion criteria and were selected for review. The overall sample size of the studies was small, ranging from 15 to 30 participants. Only one trial was considered to present with low risk for bias in the sequence generation, the concealment of allocation to treatment, and the strategy for masking. The lack of information provided by the authors of the remaining studies resulted in unclear or high risk of bias for the chief dimensions of trial quality. The heterogeneity of the studies did not allow the use ofmeta-analysis to summarize the results of several studies. Preliminary evidence originating fromasmall study suggests that ultrasonic root debridement of the second molar and a three-visit plaque controlprogrammay have a beneficial effect on PD levels on the second molar. Conclusion: The available intervention trials on this topic have important limitations, and, consequently, there is insufficient evidence to recommend the use of mechanical debridement of second molars after the extraction of third molars.