Increasingly resin composites are being used as the material of choice for dental restoration in cases of acid erosion.
Objectives:
To investigate the influence of an acidic environment on the wear resistance and mechanisms involved in the tribochemical wear (degradation) of two contemporary resin composite materials in a two body wear simulator.
Methods:
Thirty Specimens (25 × 15 × 3mm) were prepared for Filtek Supreme TMXTE (FS) (3M/ESPE) a nano filled composite and Spectrum® TPH3 (TPH)(DENTSPLY), a micro hybrid composite. Two-body wear testing in a pin-on-plate wear stimulator under 4.5N load using a steatite antagonist in pH4 and pH7 buffer solution respectively was carried out. The mean wear depth and volume loss of each specimen were calculated using a non-contact 3D profilometer. Analysis of the wear mechanisms was carried out using scanning electron microscopy and Energy Dispersive X-ray spectroscopy.
Results:
TPH showed significantly higher wear resistance compared to FS in terms of maximum wear depth and volume loss in both pH 4 and pH7 buffer solution (p< 0.05).
When comparing the two materials individually, for effect of pH on wear depth and volume loss, FS showed no significant difference between pH 4 and pH 7, while TPH showed only a significant difference in wear depth at pH7 buffer solution (p < 0.05), although no significant difference at pH4. There was clear evidence of different wear behaviour between the two materials tested with the predominant mechanisms being abrasive wear for FS and adhesive wear for TPH.
Conclusion:
Both materials showed similar behaviour in acidic and neutral environment, confirming their stability in acidic environments. TPH showed significantly higher wear resistance compared to FS in both pH 4 and pH7 buffer solutions; wear behaviour was material dependent.