Accuracy of cold sensibility testing on teeth with full-coverage restorations: a clinical study

This clinical study evaluated the reliability of the 1,1,1,2-tetrafluoroethane (Endo Ice) cold test to determine the pulpal diagnosis of teeth with full-coverage restorations (FCR). The effect of several variables on its reliability was also investigated.

Data collected from 825 patients treated in the Advanced Education Program in Endodontics at the University of Iowa, USA were analysed. The experimental group included 425 teeth with FCR, whilst the control group consisted of 400 teeth with natural crowns (NC). The pulp sensibility test results, tooth type, tooth number, type of crown, age, gender, presence or absence of caries and recent use of analgesics were recorded. Bivariate analyses were performed to assess the variables associated with the accuracy of dental pulp sensibility tests for either teeth with crowns or teeth without crowns using chi-square tests, Fisher's exact tests, Cochran-Mantel-Haenszel tests, and the Wilcoxon rank-sum tests. A P-value of less than 0.05 was used as a criterion for statistical significance, and a P-value in 0.05 < P < 0.10 was used as a criterion for marginal relevance.

The sensibility test results for FCR teeth had an accuracy of 0.866; sensitivity of 0.835; specificity of 0.879; a positive predictive value of 0.746; and a negative predictive value of 0.926. The data indicated a significant difference in the accuracy of pulp sensibility test results between the experimental and control groups (P < 0.001). Although the cold test in FCR teeth still had high accuracy, teeth with NC were significantly more likely to have true-positive and true-negative results (91.5% NC vs. 86.6% FCR, P = 0.024). No significant differences between FCR and NC were found concerning gender, tooth type, type of crown, the presence of abutment and recent use of analgesic (P > 0.05).

Pulp sensibility cold testing with 1,1,1,2-tetrafluoroethane (TFE) on teeth with FCR was less accurate than on teeth without full-coverage crowns. However, the use of TFE cold testing is still a relevant and reliable diagnostic tool, particularly for teeth with a pulpal diagnosis of symptomatic irreversible pulpitis. Clinicians should routinely carry out cold pulp sensibility testing on teeth when making a pulpal diagnosis.