Effect of Cigarette Smoke on Surface Roughness of Different Denture Base Materials

Effect of cigarette smoke and denture cleansers on the surface properties and color stability of CAD-CAM and conventional denture base resins

This study aimed to evaluate the hardness, roughness, and color stability of heat- and microwave-polymerized polymethyl methacrylate (PMMA), polyamide, and CAD-CAM PMMA resins when exposed to cigarette smoke (CS) and immersed in a denture cleanser (DC). Specimens of each resins were divided into four subgroups (n=10). The DC and CS+DC specimens were immersed in a DC; the CS and CS+DC specimens were exposed to CS; and the control (C) specimens were kept in distilled water. Hardness, roughness, and color measurements were performed. DC and CS significantly affected the roughness and color of all resins (p<0.05). However, these did not affect the hardness of the CAD-CAM PMMA resin (p>0.05). The CAD-CAM PMMA resin presented the lowest roughness, highest hardness, and lowest ΔE₀₀ values. While the roughness of all resins exposed to CS when immersed in DC decreased, the ΔE₀₀ values of the conventional PMMAs also decreased. Although this decreases were not significant, it may be advisable to use DC for smokers to decrease discoloration and roughness especially for conventional PMMAs resins.

The Effect of Smoking and Brushing on the Color Stability and Stainability of Different CAD/CAM Restorative Materials

This study aimed to investigate and compare the color stability and stainability of computer-aided design/computer-aided manufacturing (CAD/CAM) restorative materials in their glazed (G) and polished (P) state when exposed to cigarette smoke, as well as after brushing. Three CAD/CAM restorative materials were investigated: lithium disilicate CAD (LD), zirconia (Zr), and Telio PMMA CAD (PMMA), according to their surface finishing and assignment to cigarette smoking exposure or soaking in the saliva (control) group. The color change (∆E) was calculated before and after the intervention performed for all specimens, using the L*a*b values to quantitatively assess the shade differences. Statistical analysis was performed using one-way repeated measures ANOVA and Bonferroni multiple comparison analysis (α = 0.05). The surface finishing did not influence the materials’ stainability. Color change was noted after smoking, LD and Zr-G and Zr-P had a comparable color change (p > 0.05), while PMMA presented lower ∆E values (p < 0.05). After brushing, all specimens had a significant color change that was high for LD-G and LD-P, and Zr-G, compared with Zr-P and PMMA (p < 0.05). In conclusion, the exposure to cigarette smoke showed that LD, Zr, and PMMA are all susceptible to staining, but brushing decreases surface staining.

Effect of cigarette smoke on the surface roughness of two different denture base materials: An in vitro study

Aim

This study aimed to evaluate the effect of cigarette smoke on the surface roughness of two commercially available denture base materials.

Materials and Methods

A total numbers of 40 specimens were fabricated from two commercially available denture base materials: heat-cured polymethylmethacrylate and flexible denture base materials (20 for each). The specimens for each type were divided into four subgroups: subgroup I, heat-cured denture base material specimens (control group); subgroup II, flexible denture base material (control group); subgroup III, heat-cured denture base material specimen exposed to cigarette smoking group; and subgroup IV, flexible denture base material specimens exposed to cigarette smoking. The control groups were used for immersion in distilled water, and the smoke test groups were used for exposure to cigarette smoking. The smoke test group specimens were exposed to smoking in a custom-made smoking chamber using six cigarettes for each specimen. The surface roughness was measured using a profilometer, and the measurements were considered as the difference between the initial and final roughness measured before and after smoking. Paired t test and independent t-test were used to interpret differences in initial and final roughness values within and between groups respectively.

Results

Paired t-test showed a significant difference between initial surface roughness and final surface roughness within each subgroup.

Conclusion

The surface roughness of the specimens fabricated from the flexible denture base material was found to be more compared to heat-cured denture base specimens after exposure to cigarette smoke.