Orthodontic metals undergo chemical or electrochemical reactions with the oral environment resulting in dissolution or formation of chemical compounds which can affect biocompatibility as well as durability of appliances. Under several situations of the oral environment is highly aggressive to corrosion.
The objectives of the present work are to find the corrosion rate of the bracket and bracket wing in different concentrations of different spices present in Indian food using electro chemical corrosion tests.
Materials and Methods: Corrosion behaviors of bondable stainless steel brackets were studied electrochemically using the potentiostatic/galvanostatic technique. The test solutions used were aqueous extracts of mixed spices powders, coriander powder, turmeric powder, and tamarind pulp with and with out salt were used as corrodent media in different concentrations. Polarization experiments were carried out using a Potentiostat Corrosion Measurement System. Optical microscopy images and SEM images of brackets of as-received and those corroded in different aqueous extracts are examined.
Results: The corrosion rate is low in the solution which contains NaCl. The anodic polarization curves of different solutions suggest that NaCl definitely reduces the corrosion rate. In the case of tamarind solution, a solution of concentration 10g/l gives a low corrosion rate. Pitting corrosion is the mode of corrosion in most of the cases. As the passive layer formed on the surface disappears as the pitting proceeds. Pitting corrosion is not observed in the case of distilled water without and with NaCl. Similarly, there is no pitting in the case of tamarind and coriander extracts.