Objectives: The purpose of this study was to determine the effect of acidic food and drinks (Cola soft drink, drinking yogurt, orange juice, sports drink, Tom-yum soup) on surface hardness of various substrates (enamel, dentine, universal composite, microfilled composite, conventional glass ionomer, resin-modified glass ionomer, polyacid-modified resin composite).
Methods: Specimens (n = 10) were alternately immersed, 5 s each, in food or drinks and in artificial saliva for 10 cycles. Baseline and post-immersion Vickers hardness were compared using paired t-test. The difference in hardness between the groups was analysed with one-way ANOVA followed by a least significant different (LSD) test.
Results: Cola soft drink significantly reduced surface hardness of enamel, dentine, microfilled composite, and resin modified glass ionomer (p < 0.05). Orange juice and sports drink significantly reduced surface hardness of enamel (p < 0.05). Drinking yogurt and Tom-yum soup did not reduce surface hardness of any substrate.
Conclusion: This in vitro study confirms the erosive potential of certain acidic food and drinks that public should be aware of.