Factors modifying the erosive potential of liquid medicines in vitro

Objectives: Medicines used long-term and retained in the mouth for some time can place patients at risk from caries if the medicines contain sugars and erosion if they contain acids. This study investigated the effect of acidity and viscosity of a number oral liquid medicines on dental enamel by comparing the tooth surface loss induced by four test medicines and positive and negative controls using an in-vitro technique.

Method: 36 enamel slabs prepared from erupted human third molars were lapped, randomly divided into six groups and stored in 0.5% Chloramine T . Each slab was exposed to one of 4 medicines with the following properties: Gaviscon (G) Neutral pH- high viscosity, Zantac (Z) Neutral pH-low viscosity, HalibOrange (H) low pH- high viscosity, Baby Meltus (B) low pH- low viscosity. Citric acid 1% (C) and distilled water (W) acted as positive and negative controls respectively. Each specimen was placed in an automatic tooth brushing machine with a test liquid medicine and exposed to 10,000 cycles over period of 80 min.Tooth surface loss was quantified by stylus profilometry. 

Results:

Conclusion: This study showed that the acidity of oral liquid medicines is more important than their viscosity when determining their potential to cause dental erosion.