RESUMEN
OBJECTIVES: The objective of the study was to assess the impact of periodontal crown lengthening surgery on clinical parameters at adjacent and non-adjacent sites compared to treated sites. MATERIAL AND METHODS: An electronic search was carried out on MEDLINE-PubMed, The Cochrane Library, and ISI Web of Science databases between 1978 and 2015. Methodological quality assessment was based on Cochrane recommendations. Meta-analyses were assessed with RevMan 5.0 and heterogeneity between studies by the Higgin test (I 2). Clinical attachment level (CAL) and probing depth (PD) were the primary outcome variables. Four case series studies were included and three in the meta-analysis. All studies showed high risk of bias. RESULTS: The surgery promoted significant changes in treated, adjacent, and non-adjacent sites. There were greater changes in PD (mean difference -0.14, 95 % CI -0.18 to -0.10, p < 0.00001) and CAL (mean difference 0.16, 95 % CI 0.13 to 0.20, p < 0.00001) in treated sites when compared to adjacent and non-adjacent sites for PD (mean difference -0.09, 95 % CI -0.12 to -0.05, p < 0.00001) and CAL (mean difference 0.91, 95 % CI 0.87 to 0.94, p < 0.00001). CONCLUSION: Crown lengthening surgery results in changes of clinical parameters in treated, adjacent, and non-adjacent sites. CLINICAL RELEVANCE: Clinical and esthetic alterations on the adjacent/non-adjacent teeth can lead to clinical and esthetic alterations, which must be considered in surgical planning.