Objectives: To test if cigarette smoke (CS) causes discoloration
of enamel, dentin, and composite resin restorations and induces
color mismatch between dental hard tissues and the
restorations, and to compare the findings with the effects of
aerosol generated by the tobacco heating system (THS) 2.2.
Method and materials: Twenty-two human premolars were
prepared with Class V cavities restored with Filtek Supreme
Ultra (3M Espe) composite resin. Teeth were divided into two
groups and exposed to either CS from 20 reference cigarettes
(3R4F) or aerosol from 20 THS 2.2 tobacco heat sticks 4 days a
week for 3 weeks. CIE L*a*b* color was assessed before and
after exposure and brushing at 1, 2, and 3 weeks. Color match,
marginal discoloration, marginal integrity, and surface texture
of the Class V restoration were assessed according to a modified US Public Health Service (USPHS) criterion. Results:
Marked discoloration of enamel and dentin was observed following
3 weeks of CS exposure (ΔE = 8.8 ± 2.6 and 21.3 ± 4.4,
respectively), and color mismatch occurred between the composite
resin restorations (ΔE = 25.6 ± 3.8) and dental hard tissues.
Discoloration was minimal in the enamel, dentin, and
composite resin restorations in the THS 2.2 group, and no color
mismatch was observed after 3 weeks of THS 2.2 aerosol exposure.
Conclusion: CS causes significant tooth discoloration
and induces color mismatch between dental hard tissues
and composite resin restorations. Reducing or eliminating
the deposits derived from tobacco combustion could minimize
the impact of tobacco products on tooth discoloration.