Evaluation of accuracy, reliability, and repeatability of five dental pulp tests

Introduction

The aim of this study was to compare the clinical accuracy, reliability, and repeatability of laser Doppler flowmetry (LDF), an electric pulp test (EPT), and various thermal pulp sensibility tests.

Methods

Pulp tests were done on 121 teeth in 20 subjects by using LDF, EPT, and thermal pulp testing (CO₂, Endo Frost [EF], Ice) during 2 or 3 test sessions with at least 1-week intervals. The order of testing was reversed on the second visit. A laser Doppler flowmeter was used to measure mean pulp blood flow (Flux) calibrated against a brownian motion medium and zeroed against a static reflector. The laser source was 780 nm, with 0.5-mm fiber separation in the probe, 3.1 kHz as the primary bandwidth for filter set to 0.1-second time output constant. Customized polyvinylsiloxane splints were fabricated for each participant, and a minimum of 90-second recording time was used for each tooth. Raw data were analyzed by using repeated measure analysis of variance, pairwise comparisons, and interclass correlations (ICC).

Results

The accuracy of EPT, CO₂, and LDF tests was 97.7%, 97.0%, and 96.3%, respectively, without significant differences (P > .3). Accuracy of EF and Ice was 90.7% and 84.8%, respectively. EPT (P = .015) and CO₂ (P = .022) were significantly more accurate than EF. LDF was more accurate than EF, but this was not statistically significant (P = .063). Ice was significantly less accurate than EPT (P = .004), CO₂ (P = .005), LDF (P = .006), and EF (P = .019). With the exception of Ice (effect of visit: F_2,38 = 5.67, mean squared error = 0.01, P = .007, η²_p = 0.23), all tests were reliable. Ice (ICC = 0.677) and LDF (ICC = 0.654) were the most repeatable of the tests, whereas EPT (ICC = 0.434) and CO₂ (ICC = 0.432) were less repeatable.

Conclusions

CO₂, EPT, and LDF were reliable and the most accurate tests, but CO₂ and EPT were less repeatable yet less time-consuming than LDF. EF was reliable but not as accurate as EPT and CO₂ and less repeatable than Ice and LDF. Ice was the most repeatable but the least accurate and least reliable test.