AimA systematic review/meta-analysis was performed to evaluate pain during probing, scaling and root planing using intra-pocket anaesthesia versus placebo in adult patients. MethodsA search was performed in PubMed, Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature database, Brazilian Library in Dentistry, Cochrane Library and Grey literature. IADR abstracts, unpublished trials registries, dissertations and theses were also searched for randomized clinical trials comparing the clinical effectiveness of intra-pocket anaesthesia and placebo. Risk/intensity of pain was the primary outcome. The risk of bias tool from the Cochrane Collaboration was used for quality assessment. Meta-analysis was performed on studies considered at low risk of bias. ResultsA total of 1740 articles were identified. Eleven remained in the qualitative synthesis, and nine studies were considered at low risk of bias for meta-analysis. Standardized Hedge's g mean difference for pain intensity using visual analogue scale and Heft-Parker pain scales was -0.576 (95% confidence interval [CI] -0.94 to -0.22; p=0.002) and for verbal rating scale pain scale it was -1.814 (95% CI -3.38 to -0.245; p=0.023). The odds ratio for the risk of pain was 0.025 (95% CI 0.003 to 0.25; p=0.002) and the odds ratio for the need for rescue anaesthesia it was 0.358 (95% CI 0.174 to 0.736; p=0.005). ConclusionsThe anaesthetic gel decreases the risk and intensity of pain during probing/SRP.