Bilayer technique and nano-filled coating increase success of approximal ART restorations: a randomized clinical trial.

Background The high-viscosity consistency of glass ionomer cement ( GIC) may lead to its incorrect adaptation into the cavity and therefore to restoration failure. Aim To compare two different insertion techniques for GIC in approximal atraumatic restorative treatment ( ART) restorations and two different surface protection materials. Design Approximal caries lesion in primary molars from 208 schoolchildren was randomly assigned into four groups: G1, conventional GIC insertion protected with petroleum jelly ( PJ); G2, bilayer technique protected with PJ; G3 conventional GIC insertion protected with nano-filled particles coating for GIC ( NPC); G4, bilayer technique protected with NPC. Restorations were evaluated after 1, 6, 12, 18, 24, and 36 months. Kaplan-Meier survival analysis and log-rank test were performed. Cox regression analysis ( α = 5%) was used to verify the influence of clinical factors. Results Restoration survival was 52.8%. Log-rank test indicated a better survival of the bilayer technique restorations, compared to conventional restorations ( P = 0.005), whereas the coated conventional restorations presented higher survival than the uncoated ones ( P = 0.035). Cox regression analysis showed no influence of any clinical tested variables. Conclusion The survival rate of the approximal ART restorations is positively influenced by the bilayer technique, and the application of nano-filled coating increases the longevity of the conventional approximal ART restorations. [ABSTRACT FROM AUTHOR]