A parallel sided randomised controlled trial to determine if the process of warming composite resin restorative material prior to placement of a restoration leads to changes in postoperative sensitivity.

Objectives: To determine if preheating a composite resin restorative material leads to an increase in postoperative sensitivity after 24 hrs.
Methods: 120 patients (aged between 18 and 70) from a private primary care dental practice who required a one or two surface restoration were randomly divided into two groups of 60. One group had a microhybrid composite placed at room temperature the other group had the composite warmed to 39^oC before placement. The patients were randomly allocated to each group by the Dental Translational Research Unit, University of Leeds. All recruitment and procedures were carried out by a single operator. VAS sheets were used to record sensitivity scores before restoration placement and to measure the primary outcome after 24 hours. Additional sheets were used to record secondary outcomes at 1 week, 2 weeks and 1 month. The patients were telephoned to remind them to fill in the sheets. The operator and patients were blinded to the type of intervention throughout the study.
Results: 120 patients were recruited and randomised. Data from 57 patients in the heated group and 58 in the room temperature group were analysed. A Shapiro-Wilk test indicated a non-parametric analysis would be required (p < 0.05). A Mann-Whitney test of postoperative sensitivity showed no detectable difference between the 2 sides of the trial. The null hypothesis was retained that there is no difference in postoperative sensitivity between composites placed at room temperature and preheated to 39^oC (p-value of 0.162).
No adverse effects were reported throughout the trial.
Conclusions: There was no difference in postoperative sensitivity between the two groups.

This study was part of a Masters research project. Trial register/number: ISRCTN76727312