Long-term survival of structurally compromised tooth preserved with crown lengthening procedure and restorative treatment: A pilot retrospective analysis

Aim: Since there is limited study to assist in an evidenced-based decision whether to extract or preserve a structurally compromised tooth, the aim of this retrospective study was to investigate the long-term survival rate of tooth preservation after crown lengthening procedure (CLP) and restorative treatments. Methods: Electronic and paper chart of patients received CLP in our graduate clinic from 1990 to 2015 were reviewed. Statistical analysis was done using Cox regression analysis and Kaplan–Meier estimator. Results: A total of 766 coded charts were initially collected. Four hundred and fourteen cases were included in the final analysis. The Kaplan–Meier estimate shows a cumulative survival rate of 88.3% in 5 years, 78.4% in 10 years and 68.1% in 15 years. In terms of reasons for failure, restorative problem such as recurrent decays was the main issue (35.2%), followed by fracture (29.6%), endodontic complications (23.9%) and periodontal breakdown (11.3%). Conclusions: Within the limitation of this study, structurally compromised teeth have a reasonable long-term survival rate close to 80% after 10 years in a teaching institute. Patients with high fracture or caries risk may pose a higher chance of failure. Objective information should be presented to the patient to arrive at an evidence-based decision.