Comparison of using calcium hydroxide or a dentine primer for reducing dentinal pain following crown preparation: a randomized clinical trial with an observation time up to 30 months

The purpose of this study was to evaluate effect of a calcium hydroxide suspension [Ca(OH)(2)] or glutaraldehyde based dentine primer (GDP) to reduce tooth sensitivity after full crown preparation. Thirty-six patients were treated with Ca(OH)2 on one tooth and with GDP on another. Patients completed a questionnaire regarding sensitivity during crown preparation, when the not-anaesthetized abutments were irritated [cotton pellet (20degreesC)]. The teeth were tested before (To) and after using the desensitizer (T-1), again after 7 days (T-2), 6 months (T-3) and 30 months (T-4). The results were registered on a visual analogue scale [0 (no pain)-100 (severe pain)]. The changes of tooth sensitivity between different testing times were analysed. The median and the (interquartile range) for the different time intervals for Ca(OH)(2) were DeltaT(0)-T-1: 5 (6-17), DeltaT(0)-T-2: 17 (14-32), and for GDP, DeltaT(0)-T-1: 9 (7-18) DeltaT(0)-T-2: 18 (16-33), the decreases in sensitivity were lower for DeltaT(0)-T-1 than for DeltaT(0)-T-2 for both desensitizers (P < 0.001). There was no statistical difference (P > 0.05) between the agents (DeltaT(0)-T-1, DeltaT(0)-T-2, DeltaT(3)-T-4). Both substances might be useful in reducing tooth sensitivity after crown preparation, but no differences in the efficacy were found when comparing the materials.