Comparison The Shear Bond Strength of New and Rebonded Damon Q and Mini-Mono® Brackets - An in Vitro Study

In fixed orthodontic treatments debonding of brackets during treatment is an unpleasant occurrence for the clinician and the patients and resultes in an increase in treatment costs and duration. For Damon Q brackets recycling would considered as an economic saving option which could be done with using of in office methods such as the sandblasting. A sample of sixty sound bovine first upper central incisers, were collected, cleaned, and mounted in acrylic blocks for shear bond strength testing. The total sample was equally divided into two main groups. Each group had 30 teeth and 30 brackets. The first group had 30 teeth bonded with metal Damon Q brackets, the second group had 30 teeth bonded with metal Mini-Mono® brackets.The study included bonding and rebonding experiments. Therefore the same brackets with their same teeth were used in bonding and in the rebonding experiments. The bonding and the rebonding procedures were done with using 3M Unitek etching, Grengloo adhasive, and Ortho solo bonding. In addition the rebonding procedure was done after cleaning the teeth and recycling their brackets with sandblasting. All specimens were recycled 5000 times for the bonding and rebonding experiments. The first and second debonding forces were done in Newton using a Zwick Roell machine. After that SBS and SRS were computed in MPa. Furthermore all the teeth, after each debonding, were examined under a digital scanning microscope VHX-5000, 50X magnifying, to performe the ARA and ARI. The collected data was statistically analyzed for descriptive statistics as well as significance of differences among the different bracket types, and their ARI scores, in the bonding and rebonding experiments. The results showed that SRS was significantly higher than SBS of both types of the brackets, and Damon Q brackets had higher SBS, and SRS than Mini-Mono® brackets, and there was no correlation between SBS, SRS and their ARI, ARA.Für Damon Q Brackets wurde das Recycling als wirtschaftliche Einsparungsoption angesehen, die mit In-Office-Methoden wie dem Sandstrahlen durchgeführt werden könnte. Die Ergebnisse zeigten, dass SRS bei beiden Arten von Brackets signifikant höher war als SBS, und Damon Q-Brackets hatten höhere SBS und SRS als Mini-Mono®-Brackets, und es gab keine Korrelation zwischen SBS, SRS und ihrem ARI, ARA