Bottom/top hardness ratio and dentin bonding stability of conventional and bulk-fill resin composites

• Published in: Brazilian journal of oral sciences 2023-05, Vol.22
• Main Authors: Marinho, Maria Eduarda Lima do Nascimento, Sousa-Lima, Rodolfo Xavier de, Chaves, Letícia Virgínia de Freitas, Borges, Boniek Castillo Dutra
• Format: Article
• Language: eng ; por
• Subjects: DENTISTRY, ORAL SURGERY & MEDICINE
• ISSN: 1677-3225; 1677-3225
• DOI: 10.20396/bjos.v22i00.8667617

Aim: To evaluate the bottom/top hardness ratio (B/T) and the dentin bonding stability of conventional and bulk-fill resin composites in high c-factor preparations. Methods: Regular conventional (Tetric N-Ceram – TNC, and Polofil Supra – PFS), regular bulk-fill (Tetric N-Ceram Bulk fill – TBF, and Admira Fusion X-tra – AFX), and low viscosity bulk-fill resin composites (Tetric N-flow – TNF, and X-tra Base – XTB) were used to restore 180 dentin conical preparations. The specimens were randomly distributed in 12 groups (n = 15) according to the resin composites and storage time-points (24 h and six months) tested. After 24 h storage, all specimens were subjected to the bottom/top hardness ratio analysis. Then, the push-out bond strength test was performed in half of the specimens and the other half were maintained for six months on water storage before testing. The failure modes were analyzed in a stereomicroscopic. The data were analyzed statistically using one- and two-way ANOVA and Tukey post-test (p 0.05). Regardless of the storage timepoint, regular bulk-fill resin composites showed the highest bond strength values statistically (p