Erosion Effects of OTC Paediatric Oral Liquids and Traditional Chinese Medicine on Primary Teeth

Abstract

Background: This study compared the in vitro erosive effects of 2 western and 2 Chinese medicinal over-the-counter paediatric medications on primary teeth in a continuous time scale. Methods: Twenty enamel blocks obtained from 10 deciduous incisors were randomly assigned into 5 groups (n = 4 each): Group GA and Group GB–paracetamol liquid (Jean-Marie Pharmacal Co. Ltd and Universal Pharmaceutical Laboratories Ltd, respectively); Group GC and Group GD–reconstituted Chinese medicinal granules (Huarun 999 and Guizhou Bailing Group Pharmaceutical Co. Ltd, respectively); and deionised water (control group). The pH levels of these liquids were assessed. The immersion process was repeated for 20 rounds. For each round, each sample was immersed in liquid for 15 seconds and then rinsed with deionised water for 15 seconds. Mean hardness ratio (MHR) at 5, 10, 15, and 20 rounds was evaluated using Vickers microhardness test. The initial and final surface morphology and chemistries were analysed by scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). Results: All 4 liquid medications have shown acidic pH (4.74–5.76). After 20 rounds of immersion, the MHR20 of the GA (0.886) and GB (0.930) groups decreased significantly from the original MH0. The GC (0.978) and GD (0.985) groups illustrated a similar trend as the deionised water control group (0.985). Despite EDS, chemical analysis showed an increase of Ca/C mole ratio after drug immersion, and no significant difference (P >.05) was found on the ratios Ca/P and Ca/C and the amounts of magnesium or sodium before and after immersion according to the Wilcoxon signed-rank analysis. Distinctive enamel loss with irregular craters, and a corroded surface with fracture lines along the border of prism head were observed in the SEM of groups GA and GB, respectively. However, findings in both Chinese medicine groups were similar, such that erosive changes were barely seen, similar to the control group. Conclusions: This study concluded that the pH of liquid medication may not be a significant factor that contributes to enamel softening. Traditional Chinese granule medications may be a safer option for primary teeth.