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

Purpose: 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.

Methods: The index was developed based on the inputs from experts in the field with a consensus on factors (4 periodontal, 2 endodontic, and 4 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 combination, an overall tooth crownability index (TCI) score along with three-factor scores were computed. The validation study included clinical and radiological assessment of cases based on the index criteria by four independent examiners (periodontist, prosthodontist, endodontist, and general practitioner).

Results: Forty teeth were assessed. The distribution of repeated selection by the examiners was quite identical to the initial (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 = 0.993).

Conclusions: A tooth crownability index has been developed for a tooth to receive a full coverage crown which has an excellent agreement and good reproducibility among the examiners. 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).