In Vitro Fatigue Resistance of Teeth Restored With Bulk Fill versus Conventional Composite Resin

Abstract

The aim of this study was to compare the fatigue resistance of restored teeth with bulk fill composite resin, conventional composite resin with incremental insertion and unprepared sound teeth. Twenty-eight extracted maxillary premolars were selected and divided into 4 groups based on composite resin and insertion technique: control (C), conventional composite resin with incremental insertion (I) and bulk fill composite resin with three (BF3) or single increment (BF1). The restored specimens were submitted to fatigue resistance test with a 5 Hz frequency. An initial application of 5,000 sinusoidal load cycles with a minimum force of 50 N and a maximum force of 200 N was used. Next, were applied stages of 30,000 load cycles with the maximum force increasing gradually: 400, 600, 800, 1000, 1200 and 1400 N. The test was concluded when 185,000 load cycles were achieved or the specimen failed. The fatigue resistance data were recorded for comparison, using the Kaplan-Meier survival curve and analyzed by log-rank test at 0.05 significance. Fractures were classified based on the position of the failure - above or below the cementoenamel junction (CEJ). Statistical analysis of the Kaplan-Meier survival curve and log-rank test showed a significant difference between groups (p=0.001). The fracture analysis demonstrated that only 28.58% of failures were below the CEJ in group C, while for groups I, BF1 and BF3 they were 42.85%, 85.71% and 85.71%, respectively. Teeth restored with composite bulk fill in both techniques present similar fatigue resistance values compared with those restored with a conventional incremental insertion of composite, while the fatigue strength values of unprepared sound teeth were higher. Furthermore, unprepared sound teeth showed a lower percentage of fractures below the CEJ.

Simplified Surface Treatments for Ceramic Cementation: Use of Universal Adhesive and Self-Etching Ceramic Primer

“…When HF, silane, and adhesive were used, the adhesive bonding (H/S/A) was more effective than the universal adhesive (H/S/UA). This finding is in accordance with those of Garboza et al [27] and can be explained by the fact that the hydrophilic part of the universal adhesive might negatively affect the bond strength. Moreover, the silane contained in universal adhesive may have increased the hydrophilicity, thereby predisposing the adhesive layer to hydrolytic degradation.…”

“…The use of silane after etching with HF is indispensable; however, the use of the adhesive is still controversial. The groups that had application of the silane (H/S/A, H/S, and H/S/UA) did not present significant statistical differences among themselves; therefore, the use of the adhesive appears dispensable; this finding corroborates with those of Garboza et al [27]. The use of HF and silane seems to be the ideal protocol because it requires fewer steps and reduces the risk of failure.…”

“…The self-etching ceramic primer (Monobond Etch & Prime) contains ammonium polyfluoride and silane in a single step. This new material aims to eliminate the toxic potential of HF and minimize the technical sensitivity of the cementation process [27]. However, the ammonium polyfluoride promotes a weaker etching pattern in the ceramic surface than HF [9, 27].…”

Bulk-Fill Composite Restorations Step-by-Step Description of Clinical Restorative Techniques Case Reports

“…Thus, the authors suggested that Bulk-fill resins might be safely indicated for restorations in posterior teeth. Furthermore, various studies have reported satisfactory performance of Bulk-fill restorations in posterior teeth, presenting results similar to those of conventional composite resins (16)(17)(18).…”

Fracture resistance of posterior teeth restored with high-viscosity bulk-fill resin composites in comparison to the incremental placement technique

“…In accordance with the present study, Rauber et al . [ 20 ] observed that there was no difference with reference to fatigue resistance when the bulk-fill resin placed in a single increment was compared to restorations placed incrementally. Furthermore, the results of this study are consistent with the study by Rosatto et al .…”