A comparative in vitro study of different composite materials in terms of aligner attachment accuracy and surface roughness using different curing irradiances.

Background: To evaluate 4 different composite resins in terms of aligner attachment accuracy and surface roughness.

Material And Methods: 160 premolars were divided into 4 groups (n=40): Group 1: GC Aligner Connect™; 2: GC Ortho Connect™; 3: 3M ESPE Filtek™ Z350 XT flowable; 4: 3M ESPE Filtek™ Z350 XT Universal. Each group was divided into 2 equal subgroups regarding curing irradiances (Power of 1000 mW/cm in subgroup A for 10s, and 3200 mW/cmin B for 3s, VALO™ Cordless-LED Curing Light). The primary objective was to compare the realized attachments with those of the virtual with 3D Geomagic software. A contact surface profiler was used for roughness measurement (Ra) as the secondary aim. The data were analysed using the IBM SPSS 25.0. The significance level was set at p<0.05.

Results: In subgroup A, the mean "excess" accuracy measurement of the 3M ESPE Filtek ™Z350 XT flowable resin was found to be higher than others. In subgroup B, the "excess" accuracy measurements of the 3M ESPE Filtek™Z350 XT flowable (0.24±0.07mm) and Universal (0.26±0.05mm) resins were significantly higher than those of the GC Aligner Connect™ resin (0.17±0.06mm), (p<0.05). According to the Ra measurements in subgroup A, the measurement of the GC Aligner Connect™ (1.75±1.09μm), GC Ortho Connect™ (0.99±1.04μm) and 3M ESPE Filtek™ Z350 XT flowable (1.33±1.16μm) resins were found to be higher than of the Universal resin (0.07±0.11μm), (p<0.05). In subgroup B, the Ra measurement of the GC Aligner Connect™ (1.74±1.81μm) was found to be higher than that of the 3M ESPE Filtek™ Z350 XT flowable (0.11±0.18μm) resin (p=0.010). Ra measurement observed for the 10-second curing factor for the 3M ESPE Filtek™ Z350 XT Flowable resin group was found to be significantly higher than for the 3-second curing factor (p<0.001).

Conclusion: In terms of "excess" value of accuracy, 3M ESPE Filtek™ Z350 XT flowable composite resin showed a higher value. The lowest surface roughness was observed for Universal restorative resin considering low power irradiation, while was observed for 3M ESPE Filtek™ Z350 XT flowable resin considering high power irradiation.