Effect of Next Generation Tobacco Products on Teeth Colouration

Objectives: Cigarette smoking has been associated with changes in the oral cavity including tooth discolouration. However, tooth discolouration effects of nicotine products such as e-cigarettes and tobacco heating products (THP) are unknown. In this study, the in vitro discolouration of tooth enamel by a scientific reference cigarette (3R4F), a prototype e-cigarette and a commercial THP (glo™) was investigated using routine teeth staining studies with bovine enamel blocks.
Methods: Test articles (TAs) were prepared by capturing the cigarette smoke or e-cigarette/THP aerosol on Cambridge filter pads followed by elution with Dimethyl Sulfoxide (DMSO). Ten bovine enamel blocks (6.5 x 6.5 mm) were prepared per TA. Samples were pre-incubated with human saliva, to form a pellicle layer, and then incubated with the TAs or DMSO control for 14 days. Baseline and daily colour readings (L*, a*, b*) were measured for individual enamel samples using a Konica Minolta CM-700d Spectrophotometer and mean colour change (ΔE) for each TA compared.
Results: After 14 days’ incubation with the TAs, 3R4F induced a statistically significant (p<0.0001) larger enamel colour change (mean ΔE value) compared to 14 days’ incubation with e-cigarette, THP and DMSO control (mean ΔE values 29.39 ± 3.57, 10.67 ± 2.64, 10.46 ± 2.30 and 12.57 ± 1.97 respectively).
Conclusions: Cigarette smoke TA significantly increased the level of discolouration on bovine enamel teeth samples. E-cigarette and THP TAs however demonstrated little or no discolouration of the enamel samples and were similar to the ‘untreated’ DMSO control. Further studies are required to assess the longer-term impact of e-cigarette and THP aerosols on tooth discolouration.