Comparative Study on Material Behaviours and Fracture Resistance of Premolars Post-Thermocycling: Evaluating Preheated Thermoviscous, Sonic Fill, and Conventional Resin Composites

R. Basheer, Rasha; Abdelmaksoud, Heba Bahgat

doi:10.21608/asdj.2025.370537.1949

Comparative Study on Material Behaviours and Fracture Resistance of Premolars Post-Thermocycling: Evaluating Preheated Thermoviscous, Sonic Fill, and Conventional Resin Composites

Document Type : Original articles

Authors

¹ Conservative Dentistry Department, Faculty of Dentistry, October University for Modern Sciences and Arts, Giza, Egypt. Restorative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia

² Conservative Dentistry Department, Faculty of Dentistry, Suez Canal University, Ismailia, Egypt. Department of Restorative Dentistry, Restorative Dentistry Clinics University Dental Hospital Faculty of Dentistry King Abdulaziz

10.21608/asdj.2025.370537.1949

Abstract

Aim: This research was formulated to investigate the fracture resistance of premolars restored using preheating thermo-viscous, sonic fill, bulk injectable, and incrementally packed nano-hybrid resin composite materials.
Materials and methods: Sixty extracted premolars were selected and standardized class II MOD cavities were prepared. Teeth were distributed randomly into six groups according to restoration techniques used: Group 1 (intact sound teeth; positive control, Group 2 (prepared cavities; negative control), Group 3 (VisCalor Bulk fill; VCB), Group 4 (SonicFill 3; SOF), Group 5 (Herculite™ XRV Ultra™; HXU), and Group 6 (G-aenial bulk injectable; GBI). All prepared teeth were then aged by thermocycling for 5000 cycles and tested for fracture resistance. The mode of fracture was identified using a stereomicroscope and scanning electron microscopy.
Results: All tested MOD restorations failed differently. The resin composite material type had a considerable impact on all specimens' load-bearing capacity (p<0.05). A statistically significant difference (p< 0.05) in the fracture resistance values of MOD cavities restored with all tested types of resin composites was recorded. No significant difference was reported between SOF and HXU according to one-way ANOVA (p=0.800).
Conclusion: GBI represents an acceptable option used for direct restorations without a superficial layer of conventional composite covering layer compared to low or high-viscosity bulk fill materials. Injectable bulk fill composites represent an optimum selection over other nanohybrid packable bulk fill materials in restoring mesio-occluso-distal cavities.

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