Wear resistance of orthodontic attachments: a comparative analysis of different composite resins in clear aligner...

Clear aligner attachments play a crucial role in facilitating tooth movement in clear aligner treatments. This in-vitro study evaluates the wear of attachments made from 4 different composite resins during orthodontic therapy.

The study included 32 extracted human premolar and molar teeth, divided into four groups based on the composite resin used: Flow Tain, Transbond XT, G-aenial Universal Flo, and Filtek Z350 XT. Horizontal rectangular attachments were bonded to the teeth, which underwent thermal cycling and tooth brushing to mimic clinical conditions. Micro-CT analysis measured volumetric and linear changes in attachment wear. Statistical analyses were conducted using the Wilcoxon Signed-Rank Test and Kruskal-Wallis test, followed by pairwise comparisons with the Mann-Whitney U Test.

All composite resins exhibited a significant decrease in attachment volume after aging. The greatest volume reduction was observed in the Transbond XT group, while the least reduction occurred in the G-aenial Universal Flo group. Significant differences were found in the occlusal and gingival thirds of the attachments, with Flow Tain showing the highest wear in all regions.

The study shows that the wear of orthodontic attachments is greatly influenced by the type of composite resin used. The results indicate that G-aenial Universal Flo composite resin may offer superior wear resistance, preserving attachment integrity more efficiently throughout orthodontic treatment than the other 3 composite resins.

The findings can assist clinicians in choosing composite materials that improve treatment effectiveness by preserving attachment integrity over time.