CED-IADR Oral Health Research Congress, Brussels, Belgium, 16 - 18 September 2021, pp.61
Objectives: The study assessed the changes in color stability, surface roughness and microhardness of three esthetic composite-resin materials after immersed in different effervescent vitamin C tablets.
Methods: Three different types of composite resins were investigated: supra-nano hybrid composite, microfilled hybrid composite, and nanofilled composite resins. Ninety disc-shaped specimens (4-mm diameter, 2-mm thickness) were fabricated using Teflon mold and divided into three groups according to the immersion solution (Redoxon, Sambucol, and distilled water as control) for both composite resins (n=10). The top surface of specimens was ground with 600 grit silicon carbide paper for the standardization. Each group was immersed in the solutions for 24 hours. Surface roughness (Ra, mm) was measured by contact profilometer, while the hardness was measured by Vickers hardness (HV) test. CIE L*a*b* coordinates were recorded by using spectrophotometer and color difference analysis (ΔE) was made using the CIEDE-2000 formula. Data were statistically analyzed using two-way ANOVA and Bonferroni correction test (p<0.05).
Results: No significant differences in surface roughness change were recorded according to the immersion solutions for both composite resin groups (p>0.05). However, there were significant differences in ΔHV of all composite resins among the control group and the effervescent vitamin C tablets (p<0.001). Highest microhardness decrease was obtained in supra-nano hybrid composite specimens when immersed in Redoxon (-8.49±1.62). Statistically significant differences (p<0.001) were found between the composite specimens immersed in the solutions in terms of ΔE values. Redoxon appeared to be associated with the most severe alteration in color (4.86±0.63).
Conclusions: Using vitamin C effervescent tablets did not have a significant change in the surface roughness values of the composite resins. However, microhardness values of all composite resin specimens were reduced. Clinically unacceptable discoloration was observed only in micro-filled hybrid composite specimens immersed in Redoxon.