An In vitro model to assess the erosive capacity of beverages

The aim of the present study was to design a model to quantitatively and qualitatively assess the erosive capacity of different beverages using direct and indirect analyses.
Ten premolars extracted for orthodontic purposes and stored in saline solution were used. The teeth were autoclaved (120° C, 1 atmosphere) during 30 minutes, and then dried at 37°C in an oven. Group A (GA): 6 premolars were sectioned longitudinally in a bucco-lingual orientation to obtain 12 samples of dental tissue. The samples were cleaned mechanically, and coated with varnish except for a 2 mm wide area between the occlusal surface and the enamel-cementum junction (ECJ). One sample of each premolar was immersed in distilled water (GAw)  (n=6) and the remaining sample was immersed in saliva (GAs) (n=6). GROUP B (GB) comprised 4 premolars. The roots were sectioned 1 mm below and parallel to the ECJ. The samples were cleaned mechanically and the remaining portion of the root was coated with varnish. The samples were weighed; half were placed in distilled water (GBw) (n=2) and the remaining half in saliva (GBs) (n=2). Regular coke (Coca Cola ®) and a sports drink (Gatorade ® orange flavor) were used. pH of each beverage was recorded on opening the container. The samples were then exposed to 10cm3 of one of the drinks during 10 minutes and rinsed in either water or saliva for 10 minutes, accordingly. Exposure was repeated twice, using fresh samples of the drinks each time. Samples in GA were sectioned perpendicularly to the longest axis of the crown and parallel to the ECJ to obtain 50μm thick sections; the areas of enamel exposed to the erosive agents were analyzed histologically. Histomorphometric determinations of the depth and extent of the experimentally induced lesions were performed using image analysis. Weight of GB samples and variations in the pH of the drinks in contact with the samples were recorded at baseline and following each exposure. The results showed variations in some indicators. Conclusion: The present model allowed assessing the erosive effect of the beverages on the enamel.
Key Words: Dental erosion – Experimental model- pH - beverage