Long-term survival of structurally compromised tooth preserved with crown lengthening procedure and restorative...

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.

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.

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%).

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.