Effects of cigarette smoke and Tobacco Heating System aerosol on discoloration and staining of ceramic and composite veneers

OBJECTIVES: To compare the effects of conventional cigarette smoke (CS) and Tobacco Heating System (THS) aerosol on surface staining and discoloration of ceramic and composite veneers using a clinically relevant in vitro model. METHODS: Forty-six human premolars were restored with either lithium-disilicate ceramic or direct composite veneers and assembled in an in vitro setup model simulating adjacent teeth and gingiva. Specimens were randomly assigned to a 3-week exposure to CS or THS aerosol. Following each daily exposure, specimens were brushed with a standard toothpaste. Color change (ΔE00) and whiteness index for dentistry (WID) were measured spectrophotometrically at baseline and weeks 1, 2, and 3 after exposure. Surface staining was scored in the gingival, mesial, distal, and body areas using a modified Lobene stain index, and cervical marginal discoloration was evaluated with modified USPHS criteria. RESULTS: Composite veneers exposed to CS showed significantly more post-brushing discoloration (ΔE00≈ 4.0; ΔWID≈ -7.2) than ceramic veneers. THS exposure caused minimal color change in both veneer types. Surface staining was consistently greater after CS than THS exposure, but accumulated over time, even with THS, especially at interproximal and gingival regions. Cervical marginal discoloration was significantly higher in CS-exposed specimens for both veneer types. CONCLUSIONS: Cigarette smoke leads to composite veneer discoloration exceeding the clinically perceptible threshold (ΔE00 > 2.25) and more severe marginal and interproximal staining than THS aerosol. When routine brushing was included, ceramic veneers showed high color stability under both exposures. Although THS induces less veneer discoloration than CS, meticulous interdental hygiene and smoking cessation remain critical for maintaining optimal esthetics. CLINICAL SIGNIFICANCE STATEMENT: Cigarette smoking leads to discoloration and marginal staining of composite veneers, even with regular brushing, whereas ceramic veneers offer greater color stability. Although heated tobacco aerosol causes less staining than cigarette smoke, both can impact interproximal areas. This highlights the importance of materials selection, hygiene instructions, and smoking cessation counseling.