Clinical Performance of Posterior Composites; Effect of Flowables

Objectives: Previous in-vitro studies were exhibited the positive effect of flowables as used under resin-based composites at stress bearing areas. The purpose of this in-vivo study was to determine the 18-month clinical performance of posterior composites and the effect of flowable layer under composite on the clinical performance. Methods: Totally 124 occlusal restorations were performed by same practitioner for 37 patients who applied for treatment to the Dept. of Conservative Dentistry. Average size but deep cavities and first molar teeth in occlusion with opposites were enrolled to the study. Forty-nine composite restorations with Tetric Ceram (TC, Ivoclar-Vivadent) and seventy-three composite restorations with TC and a thin underlying layer of Tetric Flow (TF, Ivoclar-Vivadent) were made by the manufacturers’ instructions. Teeth were evaluated by two other independent evaluators. Modified USPHS criteria were used in the study for determining the clinical performance. The restorations were evaluated at baseline, and at 6, 12 and 18 months after placement. Statistical analysis was conducted using Fisher's exact test (alpha = 0.05). Results: 18-month cumulative retention rates were %89,6 for TC group and were % 93,6 for TC+TF group. There were no statistically significant differences in retention rates and no recurrent caries was determined among all evaluated groups. Although %3 post-operative sensitivity has been recorded in the TC group, no post-operative sensitivity were recorded in the TC+TF group at the baseline evaluation. Conclusion: At the end of the 18-month, although there were no statistical significance were noted between evaluated groups, in point of numerical advantage of clinical performance and also in point of less post-operative sensitivity, the usage of flowables as a layer under composite may be recommended.