A systematic review and meta-analysis on the effects of crown lengthening on adjacent and non-adjacent sites

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