Effect of roughness and acidic medium on wear behavior of dental resin composite

Abstract

Background The aim of the study was to investigate whether the citric acid and rough surface have a synergistic effect leading to severe wear behavior of resin composite. Materials and methods Disk-shaped (Ø15 × 1.5 mm) specimens of resin composite (n = 12) with different initial roughness were prepared. Reciprocating ball-on-flat wear tests were performed under distilled water and citric acid (pH = 5.5) respectively. The coefficient of friction (COF), wear volume loss, and duration of the running-in period were quantified to assess the wear performance. And the values were analyzed with one-way ANOVA (α = 0.05). Regression analysis was applied to examine the influence of Ra values and mediums on the wear data. The wear morphology was analyzed by scanning electron microscopy and a 3D profilometer. Results The average COF was higher in distilled water than in citric acid but was independent of the surface roughness. For the composite, the volume loss of worn area and running-in period increased with surface roughness when tested under distilled water. However, these increasing trends were not found in citric acid. All specimens exhibited mild wear behavior with low COF and less superficial abrasion in acidic medium. Conclusions The effect of initial roughness on wear behavior depends on the medium. In distilled water, resin composites with high initial roughness exhibit a longer running-in time, which eventually leads to a significant increase in material loss. The adverse effects of high roughness can be alleviated by the lubrication of citric acid, which can maintain a mild wear behavior regardless of initial surface roughness.

Effect of immersion and thermocycling in different beverages on the surface roughness of single- and multi-shade resin composites

“…1 ). Several reports are in agreement with the current findings, where low pH of the solution alone doesn’t indicate the aggressiveness of surface degradation of resin composites [ 8 , 52 ]. Several other factors might contribute to the polymer’s degradation, including the crosslinking nature of the polymeric matrix, solubility parameter, and water uptake [ 52 ].…”

“…Ideally, resin composite restorations should have and maintain high color stability, surface smoothness [ 5 ], dimensional stability [ 6 ], marginal integrity [ 7 ], wear resistance [ 8 ], etc. Maintaining surface smoothness of resin composite restorations is an important requirement, as rough surfaces contribute to increased staining susceptibility and external discoloration of the restoration, plaque accumulation, gingival irritation, periodontal disease, and recurrent caries [ 9 , 10 ].…”