The combined use of packable and high-filled flowable composites significantly reduces detachment rates in fixed orthodontic retainers, indicating strong adhesive properties.
A recent in vitro study investigated the mechanical properties of combined packable and high-filled flowable composites for bonding fixed orthodontic retainers. The study, published in BMC Oral Health, aimed to determine the synergistic effects of these composites on the bonding process.
Specimens were divided into 3 groups: flowable composite (Tetric N-Flow), packable composite (Tetric N-Ceram), and a combination of both. Shear bond strength (SBS), adhesive remnant index (ARI), and wire pull-out resistance were measured. Statistical analyses included analysis of variance (ANOVA), Tukey tests, χ² tests, and Kruskal-Wallis tests.
ANOVA revealed no statistically significant differences in SBS among the groups (P = .129). Significant differences in ARI scores were observed between the flowable and packable composite groups (P = .01). The flowable composite group exhibited higher ARI scores of 1 and 2, whereas the packable composite group showed more scores of 0. Higher frequencies were found in the combined composite group with ARI scores of 0 and 1 compared with the flowable composite group alone. Wire pull-out tests indicated that the combined application resulted in significantly lower detachment rates compared with the packable composite alone (P = .008).
The combined use of flowable and packable composites demonstrated adequate SBS and favorable ARI scores. These findings indicate that this combination may be a suitable adhesive system for bonding fixed orthodontic retainers.
The authors declared no conflict of interest.