Influence of chemical degradation and abrasion on surface properties of nanorestorative materials

Abstract

Aim:The aim of this in vitro study was to investigate the synergistic effect of chemical degradation (erosion) and three-body abrasion (mechanical degradation) on the surface roughness (Ra) and hardness (KHN) of two nanorestorative materials and two conventional materials. Methods: Discshaped specimens (5 mm in diameter, 2 mm thick) of Filtek Z350 TM and TPH Spectrum TM composites and Ketac Nano TM and Vitremer TM light-curing glass ionomer cements, nanomaterials and conventional materials were prepared according to the manufacturer's instructions. After 24 h, polishing procedures were performed and initial measurements of Ra and KHN were taken in all specimens. The specimens were divided into 12 groups (n = 10) according to material and storage media: artificial saliva, orange juice, and Coca-Cola®. After 30 days of storage, the specimens were submitted to mechanical degradation and re-evaluated for Ra and KHN. Data were tested for significant differences by repeated-measure three-way ANOVA and Tukey's tests (p<0.05). Results: Erosion and abrasion wear significantly decreased hardness of all materials. Only Filtek Z350 roughness, however, was not affected by erosion and abrasion. All materials showed a significant increase in surface roughness after erosion and abrasion, except for Filtek Z350. After chemical and mechanical degradation, the KHN of all samples had decreased significantly. After mechanical degradation, the acidic drinks (Coca-Cola® and orange juice) were more aggressive than artificial saliva to all materials. Conclusions: A synergistic effect was observed by the increase in roughness for all materials, except for Filtek Z350; hardness values decrease for all materials, regardless of whether they were nanofilled or not. The RMGICs were more susceptible to degradation than the composites, considering both hardness and roughness surface parameters.

The Evaluation of Color and Surface Roughness Changes in Resin based Restorative Materials with Different Contents After Waiting in Various Liquids: An SEM and AFM study

“…We believe that these results are due to higher pH values of kefir and artificial saliva. Based on previous studies (Aliping‐McKenzie et al, ; Paula et al, ) and our research, and the roughness values obtained after the process of immersion in liquids with different pH degrees, the pH value of the fluid is not the only determining factor, and the effect of the acid type should be evaluated.…”

Effect of Food Simulating Liquids and Thermo-cycling on flexural strength and surface hardness of a Resin Nano-Ceramic CAD/CAM Material

“…The higher flexural strength and surface micro-hardness of Lava Ultimate (M 1 ) may be related to its higher filler content (80% wt fillers) compared to the other two tested materials (15) The higher filler loading with smaller particle size provides a reduction in the interstitial spacing, which effectively protects the softer matrix, reduces the incidence of filler exfoliation, and enhances the material's overall resistance to abrasion (29) . Moreover, resin composites with nanofiller showed higher flexural strength than resin composites with microhybrid fillers (30,31) .…”

Differences in surface roughness of nanohybrid composites immersed in varying concentrations of citric acid

“…16 The number of samples was 27, divided into three groups. Group 1 used nanohybrid composites immersed in citric acid at a concentration of 2509.2 ppm.…”

“…16,17 The cast was smeared with Vaseline and subsequently placed on a glass plate with a celluloid strip attached. Nanohybrid composite resin was then introduced into the cast on the glass plate covered with the celluloid strip and subjected to a weight load for 30 seconds to produce a flat and smooth surface.…”