The in vitro effect of electronic versus conventional cigarettes on color stability and surface roughness of dental resin composites

The appearance quality of dental restoration is recognized as crucial for the oral health-related quality of life. This study aimed to evaluate and compare the effect of electronic and conventional cigarettes on the color stability and surface roughness of dental composites. Eighty-four specimens of four composites (multi-shade: Tetric Prime, Neo Spectra ST-HV, and single-shade: Charisma Diamond One, Omnichroma; n = 21/material) were exposed to electronic cigarettes, conventional cigarettes, or artificial saliva (control) for 60 days using an automated smoking simulator with special robotic system for brushing, finishing, and polishing, mimicked six months of heavy smoking. Color and roughness were measured at baseline, after exposure, and post-thermocycling using a spectrophotometer and optical profilometer. Statistical analysis (SPSS v25) employed a three-way ANOVA, Bonferroni post hoc, and Pearson correlation (p < 0.05). The color stability was significantly different according to the type of treatment. In comparison, surface roughness was not affected by any treatment. The correlation between color stability and surface roughness was significant negative (p-value = 0.017). This study showed that conventional cigarettes caused higher discoloration than electronic cigarettes. While multi-shade resin-based composite materials had lower color stability than single-shade counterparts. On the other hand, neither smoking nor thermocycling negatively affected the surface roughness of materials.