Category: Laboratory Research
Award Category: Junior Scientist
Fracture Resistance of Bulk Fill and Indirect Resin Composites
Safiye Selin Koymena | Ahmad Bittara *(ahmet.baytar989@gmail.com) | Burcu Gozetici Cila | Nazmiye Donmezb
aDepartment of Restorative Dentistry, School of Dentistry, Istanbul Medipol University, Istanbul, Türkiye
bDepartment of Restorative Dentistry, Faculty of Dentistry, Bolu Abant Izzet Baysal University, Bolu, Türkiye
Objective: The study aimed to evaluate the fracture resistance of mesio-occlusal-distal (MOD) cavities restored with bulk-fill and indirect resin composite.
Methods: Freshly extracted sound premolar teeth (n=20) were used and embedded in acrylic resin 2 mm below the cementoenamel junction (CEJ). Standard MOD cavities were prepared with parallel walls without proximal boxes, a buccolingual width of 3 mm and a cavity depth of 3.5 mm. Then the teeth were randomly divided into two groups (n=10) according to restorative material. Group 1; the teeth were restored with flowable bulk-fill composite resin (Estelite Bulk-Fill Flow (EBF), Tokuyama, Japan) and Group 2; light-curing micro hybrid indirect composite resin (Ceramage, Shofu, Japan). In Group1; The cavity was cleaned, and then a three-step adhesive system (Syntac Primer/Adhesive/Heliobond System, Ivoclar Vivadent) was applied according to manufacturer instructions and restored with EBF. In Group 2; The indirect restorations were fabricated by a dental technician and photopolymerized for 300 s using a light curing unit (Labolight LV-III, GC Corp., Tokyo, Japan). A dual-cure resin cement (Variolink-N, Ivoclar Vivadent, Liechtenstein) was used for the cementation of indirect composite restorations. A fracture strength test was performed using the universal testing device (Autograph AGS-X, Shimadzu, Japan) under vertical loading at a crosshead speed of 1 mm/min with a round tip. Fractured teeth were examined under the stereo-microscope with x20 magnification, and fractures were classified as 1: cohesive; 2: adhesive; 3: adhesive-cohesive; 4: fracture of tooth/restoration above CEJ, and 5: fracture of tooth/restoration below CEJ (irreparable). The data were analyzed by Mann- Whitney U Test, Fisher’s Exact Test, and Fisher Freeman Halton Test (α=0.05).
Results: Statistical analysis revealed no statistically significant difference between the groups' load-bearing capacity and fracture types (p>0.05).
Conclusion: Micro-hybrid indirect or flowable bulk-fill composite resin can be preferable for restoring MOD cavities within the premolar teeth.
Funding/Conflict of Interest: NoneKeywords: flowable bulk-fill composite resin, MOD cavity, fracture resistance, micro-hybrid indirect composite resin
