Evaluation of the effectiveness of indirect bonding of orthodontic attachments with RMGIC Resin Modified Glass-Ionomer Cement

This article reports our study, carried out as a CECSMO assignment, assessing the effectiveness of resin modified glass ionomer cement as a bonding agent on enamel over a two year period and a consideration of the relative influence of two brands of attachments, Orthos and Damon. In our study group we had an overall rate of bonding rupture of 11.6%. 17% of direct and 33% of the indirect bondings loosened in the first trimester. Globally, the direct bonding had a higher survival rate, which was, after one year, 95.2% for the direct bonding and 90.7% for the indirect. The survival rate of attachments bonded to second molars was the lowest for all the teeth in the arch with Damon Indirect recorded at .889 after a year and Orthos Indirect .524 after a year. We categorized our results in relation to the characteristics of our sample (its size, its heterogeneity, and the duration of the observation period) and in relation to the characteristics of the attachments (their size and the surface and type of their bases) and in relation to the protocols (of indirect bonding, of preparation of enamel surface, of photopolymerization, of placement of the first arch, of bracket size, of ligature placement, and type of mechano-therapy used). Our study confirmed the hypothesis that direct or indirect bonding with Fuji Ortho LC@ functions effectively in the daily practice of orthodontics. Our rates of accidental attachment debonding and our rates of bonding survival were acceptable except in Orthos indirect bonding of mandibular teeth. We found that under the conditions of our study direct bonding functioned slightly better than indirect bonding. Practitioners need to know and understand certain parameters influencing the use of resin modified glass-ionomer cement for bonding orthodontic attachments in order to optimize its success notable with regard to the choice of attachments with respect to bonding material or the effect of overbite on retention of attachments. Furthermore, the multiplicity of interfaces and of materials utilized in indirect bonding weakened bond strength under the conditions and protocols of our study.