In vitro evaluation of the caries-preventive effect of bioactive resin composites for orthodontic clear aligner attachments

Aim: The increased risk of caries during orthodontic treatment is a significant prevention challenge. This in vitro study aimed to evaluate the caries-preventive potential of bioactive composites used in clear aligner attachments. Methods: A bioactive composite group consisted of Activa Bioactive Restorative (Pulpdent, USA), while a traditional flowable composite group included G-Aenial Universal Flo (GC, Japan). A total of 24 sound extracted human teeth were cleaned using pumice, and all surfaces except for a 3 × 3 mm area on the buccal crown were coated with acid resistant varnish. Standard acid etching and bonding protocols were applied to the exposed area, after which clear aligner attachments were created using a mould. The specimens underwent pH cycling, consisting of immersion in a demineralising solution for 48 hours followed by immersion in a remineralising solution for 24 hours, repeated three times. Sections were obtained from the attachment areas, and demineralisation depths were measured using a digital microscope. Statistical analysis was performed using an independent samples t-test. Results: The mean lesion depth for the bioactive composite (Activa Bioactive Restorative) was 120 ± 29 µm, while the traditional flowable composite (G-Aenial Universal Flo) exhibited a mean lesion depth of 150 ± 41 µm. According to the t-test results, significantly less demineralisation depth was observed in the bioactive composite group (p < 0.05). Conclusion: Under in vitro conditions, bioactive composites exhibited lower demineralisation depths compared to traditional flowable composites. The findings suggest that bioactive composites may offer caries-preventive benefits when used in clear aligner attachments, although further studies are needed to confirm the effects.