IADR Abstract Archives
Thermocycling Induces Severe Material Wear in Orthodontic Sealants
Objectives: White Spot lesions around brackets constitute a frequent side effect during orthodontic therapy. Among fluoride administration, sealing of the smooth surfaces around brackets is a widely used preventive measure to counter this issue. This investigation aimed to compare different sealing agents in terms of surface roughness and retention during thermal stress.
Methods: Six different materials were investigated, three fluoride varnishes (Bifluorid 12, Fluor Protector, Protecto CaF2 Nano) and three composite-based surface sealants (Pro Seal, Ortho Solo, Control Seal). Each product was administered to 10 bovine incisors according to the manufacturer’s protocol and surface roughness (Ra) measurements were performed by means of focus variation. Then, three consecutive interventions in the thermal cycler (5°C - 55°C, 1000 cycles) were carried out. After each intervention, Ra was measured to evaluate the roughness alterations compared to an untreated control group. Statistical analysis of mean Ra values and control group comparisons were performed using non parametric tests. Material retention was evaluated visually under 10x magnification.
Results: The composite sealants exhibited a statistically significant increase of Ra directly after administration (p ≤ 0.0003), followed by a significant reduction in relation to the thermal stress intervention (p ≤ 0.0187). This reduction led to significantly lower Ra values than the control group (p ≤0.0147). However, two materials revealed notable material dysfunction. On the other hand, fluoride varnishes exhibited a heterogenous surface roughness of which one presented with significantly higher Ra than the control group (p=0.0005). Furthermore, all fluoride varnishes were subject to substantial loss of function.
Conclusions: Composite materials outperformed the fluoride varnishes in terms of robustness towards thermal stress. However, thermally induced stress led to substantial wear in all but one sealant. Future studies should examine the influence of mechanical stress to improve translatability to the clinical performance and investigate the in vivo durability of orthodontic surface sealants.
Methods: Six different materials were investigated, three fluoride varnishes (Bifluorid 12, Fluor Protector, Protecto CaF2 Nano) and three composite-based surface sealants (Pro Seal, Ortho Solo, Control Seal). Each product was administered to 10 bovine incisors according to the manufacturer’s protocol and surface roughness (Ra) measurements were performed by means of focus variation. Then, three consecutive interventions in the thermal cycler (5°C - 55°C, 1000 cycles) were carried out. After each intervention, Ra was measured to evaluate the roughness alterations compared to an untreated control group. Statistical analysis of mean Ra values and control group comparisons were performed using non parametric tests. Material retention was evaluated visually under 10x magnification.
Results: The composite sealants exhibited a statistically significant increase of Ra directly after administration (p ≤ 0.0003), followed by a significant reduction in relation to the thermal stress intervention (p ≤ 0.0187). This reduction led to significantly lower Ra values than the control group (p ≤0.0147). However, two materials revealed notable material dysfunction. On the other hand, fluoride varnishes exhibited a heterogenous surface roughness of which one presented with significantly higher Ra than the control group (p=0.0005). Furthermore, all fluoride varnishes were subject to substantial loss of function.
Conclusions: Composite materials outperformed the fluoride varnishes in terms of robustness towards thermal stress. However, thermally induced stress led to substantial wear in all but one sealant. Future studies should examine the influence of mechanical stress to improve translatability to the clinical performance and investigate the in vivo durability of orthodontic surface sealants.