Experimental in vitro simulation of the impact of e-cigarette vapors on enamel and dentin

The aim of this study was to evaluate changes in tooth color and the bond strength of resin to enamel and dentin after exposure to electronic cigarette (e-cigarette) vapor in an in vitro vaping model, as well as to analyze the chemical composition of the materials present in the vapor. A device with a vacuum pump simulated vaping. Eighty dental slabs (40 dentin and 40 enamel) and were randomly divided into two groups. Half received e-cigarette exposure, and the other remained without vaping (control). Color changes were measured using a spectrophotometer (CIELAB). Composite cylinders were built on substrates using etch-and-rinse or self-etch strategies and subjected to loading tests. Gas chromatography-mass spectrometry (GC-MS) analyzed the organic compound of the e-liquid, while inductively coupled plasma mass spectrometry (ICP-MS) assessed the metal content. Statistical analysis was conducted using MANOVA and ANOVA (α = 0.05), and CIEDE2000 formula. E-cigarette exposure darkened (L*) and yellowed (b*) enamel and dentin. Bond strength in dentin decreased for both adhesion strategies, and in enamel using the etch-and-rinse adhesive. GC-MS identified 72 different volatile compounds, whereas ICP-MS detected 26 distinct metals. Among metals, eight exceeded the WHO (World Health Organization) tolerance limits. E-cigarette exposure altered the color of substrates and reduced resin bond strength in dentin for both adhesives, and in enamel restored with the etch-and-rinse technique. E-liquid had toxic organic compounds and metals. Exposure to e-cigarette can cause tooth discoloration and weaken bonding to dental tissues. Toxic volatile organic and metallic compounds present in vapor can adversely affect oral health.