Low- and high-viscosity bulk-fill resin composites

• Published in: Acta odontológica latinoamericana Vol. 34; no. 2; pp. 173 - 182
• Main Authors: França, Fabiana M. G., Tenuti, Jonathan G. B., Broglio, Isabela P., Paiva, Lara E. J., Basting, Roberta T., Turssi, Cecília P., Amaral, Flávia L. B. do, Reis, André F., Vieira-Junior, Waldemir F.
• Format: Journal Article
• Language: Portuguese
• Published: Sociedad Argentina de Investigación Odontológica 01.06.2021
• Subjects: DENTISTRY, ORAL SURGERY & MEDICINE; hardness; dureza; viscosity; falha de restauração dentária; viscosidade; resinas compostas; composite resins; dental restoration failure
• ISSN: 1852-4834

ABSTRACT The aim of this study was to compare low- and high-viscosity bulk-fill composites for Knoop microhardness (KHN), microtensile bond strength (MTBS) to dentin in occlusal cavities, and fracture strength (FS) in molars with mesialocclusal- distal restoration. Disk-shaped samples with different thicknesses (2 or 4 mm) of low-viscosity (SDR Flow, Dentsply) and high-viscosity bulk-fill composites (Filtek BulkFill, 3M ESPE; and Tetric-N Ceram Bulk Fill, Ivoclar Vivadent) were prepared for top and bottom KHN analysis (n=10). MTBS to dentin and fracture pattern was evaluated in human molars with occlusal cavities restored with (n=10): conventional nanocomposite (Z350XT, 3M ESPE), low-viscosity (Filtek Bulk-fill Flow, 3M ESPE) or high-viscosity bulk-fill composites (Filtek BulkFill). The FS and fracture pattern of human molar with mesial-occlusal-distal restorations submitted or not to thermomechanical cycling were investigated (n=10) using: intact tooth (control), and restoration based on conventional microhybrid composite (Z250, 3M ESPE), low-viscosity (SDR Flow) or high-viscosity bulk-fill composites (Filtek BulkFill). The data were submitted to split-plot ANOVA (KHN), one-way ANOVA (MTBS), two-way ANOVA (FS) followed by Tukey’s test (α=0.05). For KHN, there was no significant difference for the resin composites between the top and bottom. For MTBS, no significant differences among the materials were detected; however, the low-viscosity composite presented lower frequency of adhesive failures. For FS, there was no significant difference between composites and intact tooth regardless of thermomechanical cycling. Low- and high-viscosity bulk-fill composites have comparable microhardness and microtensile bond strength when used in occlusal restorations. Likewise, the bulk-fill composites present similar fracture strength in molars with mesio-occlusal-distal restorations.