[The effect of gastric juice on the development of erosive changes in hard dental tissue]

Gastroesophageal reflux disease (GERD) is an esophageal disorder where the refluxed gastric contents enters first into the esophagus followed by the pharynx, oral cavity, larynx, airway and middle ear, causing a range of disorders and symptoms. Hydrochloric acid from the gastric contents is responsible for the demineralization of dental hard tissues and release of matrix metalloproteinase from the dentin.

The aim of this study was to verify the SEM (scanning electron microscopy) analysis of the surface enamel, the enamel-dentin border and dentine after the exposure of intact teeth to filtrate of gastric contents obtained during routine endoscopy.

Material used in the research was 10 extracted human impacted third molars. The coronal part of the tooth was divided into two parts, and then the two halves of teeth were exposed to the filtrate of gastric juice obtained during routine gastroscopy, which had been frozen until the moment of the experiment initiation. All samples of teeth were immersed in the filtrate of the content at a temperature of 20 degrees C for 60 minutes. The prepared samples were observed by the SEM in the area of the enamel, the enamel-dentin border and in the area of dentin at different magnification.

The SEM analysis showed that both enamel and dentin had a significant demineralization of these tissues. Enamel surface resembled a demineralization similar to that of acid conditioning before the application of composite restorations. The degree of mineralization was more intense towards the enamel - dentin border, and at this area the enamel prisms were not fully recognizable. The dentin had a complete loss of peritubular dentin, the entry points of the dentin tubules were expanded and intertubular dentin demineralization was also registered.

SEM analysis showed a significant degree of destruction of enamel and dentin. Significant changes in the surface structure of enamel and dentin were also registered. The filtrate of the gastric juice degrades enamel pellicle and the dentin organic component.