Development of an Index for a Tooth to Receive a Full-Coverage Crown

To develop a system for assessment of the status of a tooth to receive a full coverage crown and depict it on a measurable scale, and to validate its use by assessing examiner reproducibility.

The index was developed based on the inputs from experts in the field with a consensus on factors (four periodontal, two endodontic, and four prosthodontic), stages of severity (stage 1 to stage 4), assigned scores, and relative weights pertaining to varied clinical scenarios. Based on the selection of factor-stage combinations, an overall tooth crownability index (TCI) score along with three-factor scores were computed. The validation study included clinical and radiologic assessment of cases based on the index criteria by four independent examiners (periodontist, prosthodontist, endodontist, and general practitioner).

A total of 40 teeth were assessed. The distribution of repeated selection by the examiners was very similar to the initial distribution (kappa = 0.93). There was no statistically significant difference in the mean scores of examiners in TCI and factorial scores. An excellent agreement between the measurements was observed among the examiners (ICC = 0.993; Crohnbach α = .993).

TCI with excellent agreement and good reproducibility among the examiners has been developed for a tooth to receive a full-coverage crown. TCI will serve as a baseline tool in treatment plan decision-making based on the status of the teeth and in research for evaluating the efficacy of various treatment options available (standard criteria for outcome assessment).