[Improvement in the adhesive strength of orthodontic brackets on unit-cast and fired dental alloys by microsandblasting].

This experimental study employed an Instron test machine to measure the bond strength of metal brackets to cast test specimens made of 6 different dental alloys. An easily replicated method for testing the shear bond strength is presented, which corresponds to the international recommendations for testing bond strength of orthodontic brackets. The study found that the different methods of surface preparation, such as micro-sandblasting and the use of chemical sealants, had distinct effects on the magnitude of bond strength gauged. Also tested was whether the storage medium prior to debonding influenced the bond strength. The measured values from a series of tested bovine teeth, which were bonded by means of the conventional acid etch method and with the same adhesive, served as a control group. An extended statistical analysis showed that the use of the methods described can achieve a clinically acceptable bond of brackets to dental alloys for prosthetic restorations.