AimSince there is limited study to assist in an evidencedâ based decision whether to extract or preserve a structurally compromised tooth, the aim of this retrospective study was to investigate the longâ term survival rate of tooth preservation after crown lengthening procedure (CLP) and restorative treatments.MethodsElectronic 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 Kaplanâ Meier estimator.ResultsA total of 766 coded charts were initially collected. Four hundred and fourteen cases were included in the final analysis. The Kaplanâ 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%).ConclusionsWithin the limitation of this study, structurally compromised teeth have a reasonable longâ 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 evidenceâ based decision.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149679/1/jcpe13124.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149679/2/jcpe13124_am.pdf