Fracture Resistance of Bulk Fill Composite Restorations of Anterior Primary Teeth with Four Different Reinforcement Methods

Background: The study compared the fracture resistance of bulk fill composite restorations of anterior primary teeth using four different reinforcement methods. Methods: Forty-eight extracted human maxillary primary incisors were randomly divided into four groups: The first group was the conventional composite posts (CCP), the second group was the fiberglass posts (FGP), the third group was the pin and composite posts (PCP), and the fourth group was the dentinal pin (DP). The samples were prepared and underwent 5000 thermo-cycles. A Universal Testing Machine applied an increasing force at a 0.5 mm/min crosshead speed until fracture occurred. The fracture resistance was then reported in Newtons (N). Data were analyzed using SPSS version 20. One-way ANOVA and Tukey HSD tests were applied with a significance level of 0.05. Results: The mean fracture resistance in the four groups was 825.61 ± 74.54 N, 540.10 ± 51.61 N, 758.03 ± 60.94 N, and 498.88 ± 54.59 N, respectively. The results of the one-way ANOVA showed a significant difference among the study groups in terms of fracture resistance (P = 0.001). The fracture resistance of the CCP group was significantly different from the DP group (P = 0.022), with CCP exhibiting a significantly higher mean fracture resistance. The fracture resistance of the FGP was significantly different from the PCP and DP groups (P = 0.010 and P = 0.003, respectively), with FGP exhibiting a significantly higher mean fracture resistance. Conclusions: According to the results of this study, the best reinforcement methods for bulk fill composite restorations in anterior primary incisors were FGP and CCP.