Evaluation of an Orthodontic Adhesive with Combined Primer and Composite

摘要

Objectives: To investigate the efficacy of a new orthodontic bonding system that incorporates the primer solution in the adhesive. Materials and Methods: 90 anterior bovine teeth were divided in three groups: in Group I, brackets were bonded with Transbond XT system, in Group II with GC Ortho Connect which incorporates the primer in the adhesive, and in Group III, a single layer of primer was applied on the teeth before bonding the brackets with GC Ortho Connect. After a 24-hour latency period, Shear Bond Strength (SBS) and Adhesive Remnant Index (ARI) were measured. In cases with remnants left mainly on the bracket base, energy dispersive X-ray (EDX) spectrometry was performed in order to determine the presence of calcium particles. Selected cases were examined with Scanning Electron Microscopy (SEM) analysis and in nanometer scale with a confocal visible light microscope (μsurf revolver, NanoFocus AG, Germany). Results: The mean SBS values were 7.25 ± 0.58 MPa for Group I, 6.57 ± 0.50 MPa for Group II and 7.33 ± 0.56 MPa for Group III. These differences were not statistically significant (p = 0.562). ARI evaluation showed that the debonding failure happened more frequently within the adhesive interface in Group II, whereas this occurred more often at the tooth-adhesive interface in Group III. However, statistical analysis of the ARI scores showed no significant difference in adhesive remnants among the three groups (p = 0.078). Conclusion: The GC Ortho Connect bonding system can be efficiently used for orthodontic bonding. Adding a layer of primer appears to slightly increase the SBS while causing less adhesive to remain on enamel from which brackets were debonded.