Orthodontic bonding technique involving 10-Methacryloyloxydecyle dihydrogen phosphate for gold alloy surfaces

Abstract

The increase in the demand for adult orthodontics made the bonding of orthodontic appliances to prosthetic surfaces a necessity. The objective of this study was to evaluate the shear bond strength of metal orthodontic tubes bonded to gold alloy surfaces with different surface preparations and different adhesive systems, and to compare the performance of 10-methacryloyloxydecyle dihydrogen phosphate (10-MDP) with conventional methods. The sample specimens consisted of sixty Type III gold alloy plates (Au 50%, Pd 5%, Ag 32.5%, Cu 11.45%) of a standardized size embedded in cylinders of self-curing acrylic resin. The plates were allocated into four groups, fifteen each, according to different combinations of bonding techniques. The metal orthodontic tube used in this study was a mandibular right first molar direct bond tube with a base area of 20.08 mm². The preparation for each group is as follows: Group 1, the gold alloy plates were sandblasted with 50µm aluminum trioxide using intraoral sandblaster. Metal primer (Reliance, Reliance Orthodontic Products, IL, USA) was applied. The tubes were bonded with Transbond XT (3M Unitek, CA, USA) and light-cured with a LED curing light

Group 2, sandblasting was done with 30µm silicon dioxide for silica coating of the gold plates. Silane (Porcelain Primer, Bisco, Schaumburg, IL, USA) was applied. Bonding was carried out in the same manner as in Group 1

Group 3, the gold plates were sandblasted in the same way as Group 1. Z-Prime Plus (Bisco, Schaumburg, IL, USA) was applied. Bonding of the tube was performed in the same manner as Groups 1 and 2

Group 4, the gold plates were sandblasted with aluminum trioxide in the same way as in Groups 1 and 3. Panavia F2.0 (Kuraray Medical Inc, Japan) was used to bond the tubes. Light curing was done in the same manner as in Groups 1, 2 and 3. Shear bond strengths of each group were evaluated with universal testing machine (Instron 4466, Instron Corporation, Canton, Mass, USA) after 1 hour of storage in room temperature. Following the debonding of the tubes, the adhesive remnant index (ARI) was assessed. Data were analyzed by using language R program. Test of normality and homoscedasticity were performed using Shapiro test and Levene test. Comparison of shear bond strengths among groups was performed with one-way analysis of variance (ANOVA) followed by the Tukeys multiple comparison test, with P<.05 considered statistically significant. The differences in ARI scores were evaluated, and the pattern of adhesive remnants was observed. Group 1 showed the lowest mean SBS value of 6.70 MPa, and Group 3 showed the highest mean SBS value of 9.81 MPa. Statistically significant differences existed between Groups 1 and 2, and between Groups 2, and 4 (P<0.001). There were no statistically significant differences between Groups 4 and 3. The ARI scores showed that significant differences were observed between Groups 3 and 4, and between Groups 3 and 2. The results revealed that 10-MDP showed promising performance in bonding to gold alloy surfaces. The SBS values of tubes bonded with 10-MDP containing adhesive systems such as Panavia F2.0 and Z-Prime Plus were found to be better than bonding systems using 4-META or silicoating.