An experimental fibre reinforced composite (FRC) has been developed as a potential core material to enhance the strength of composite restorations. Normally, the core would be covered by a veneering composite, but should the core inadvertently become exposed to the mouth its abrasion resistance must be evaluated.
Objective: To assess the resistance of an experimental FRC to manual toothbrush wear.
Methods: Samples of composite resins 12 mm in diameter and 2 mm deep were prepared in rectangular Perspex blocks. After finishing, polishing and water storage for at least 24 hours, each specimen was subject to 50000 brushing cycles in an ISO standard toothbrushing simulator with a water/dentifrice slurry. 4 specimens were prepared from each of the experimental FRC (Stick Tech), a conventional particulate composite resin (Z250 (3M ESPE)) and a commercially available FRC (Build It FR (Pentron Clinical)). Each sample was assessed using a laser profilometer and the maximum depth of the wear track used as a measure of total wear. Differences between specimens were assessed using ANOVA and Tukey's test.
Results: The results shown in table 1 clearly indicate that the experimental FRC is more susceptible to wear than either the PFC or the commercially available FRC. ANOVA showed a significant difference (P<0.05). Laser profilometer and SEM images confirmed an irregular wear track surface for the experimental FRC.
Conclusion: It is important that restorations made with the experimental FRC are designed to ensure the core is properly covered by the veneering material.
Table 1 Mean depth of wear track after testing
Material | Mean Depth (µm) | Standard Deviation |
Experimental FRC | 55.4 | 9.4 |
Z250 | 7.1 | 2.9 |
Build It | 7.0 | 4.1 |