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

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.

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.

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).

Crown lengthening surgery results in changes of clinical parameters in treated, adjacent, and non-adjacent sites.

Clinical and esthetic alterations on the adjacent/non-adjacent teeth can lead to clinical and esthetic alterations, which must be considered in surgical planning.