Assessing Fracture Resistance of Restored Premolars with Novel Composite Materials: An In Vitro Study

Abstract

During restorative treatment, premolars restored with resin filling materials using the conventional incremental-fill technique take longer restoration time and undermine the integrity of the tooth. The aim of this study was to assess fracture resistance of premolars restored by various types of novel bulk-fill composite resin materials. Forty-eight (n = 48) freshly extracted sound maxillary first premolars were used in this in vitro study. The teeth were divided into six groups, each having 8 specimens. Group A (positive control) was allocated for the intact teeth. For specimens in Groups B to F, a large cavity (Class-II MOD) was prepared with a standardized dimension of cavity (3 mm depth on the pulpal floor, 4 mm at the gingival seat, and 3 mm cavity width). Group B represented prepared teeth without any restoration. Group C, Group D, Group E, and Group F were restored with Tetric EvoCeram® incremental-fill (conventional), Beautifil bulk-fill, Filtek posterior bulk-fill, and SonicFill 2 bulk-fill restorative materials, respectively. All samples were finished and polished with an enhanced finishing kit and stored in distilled water for a month before the fracture resistance testing. All the samples were exposed to the axial loading (the speed of crosshead was 1 mm/min) in a computer-controlled universal testing machine (LARYEE, China) via a steel bar (6 mm in diameter) and the maximum applied force in Newton was recorded as the fracture resistance. One-way analysis of variance (SPSS 21) was used to compare the fracture resistance within the groups, and Tukey’s post hoc test was used to determine the difference between the groups. The lowest value of fracture resistance was recorded for Group B, and the highest value was recorded for Group A followed by the values of Group D, Group C, Group F, and Group E. One-way ANOVA revealed a statistically significant difference between the groups ( P < 0.05 ). Nonsignificant difference was found between the premolars restored by bulk-fill and conventional composites. Among the bulk-fill restored specimens, Beautifil restorative demonstrated significantly higher fracture resistance in comparison with the other two bulk-fill restored specimen groups (SonicFill 2 and Filtek). Bulk-fill composite such as Beautifil could be an alternative option to conventional incremental-fill composite for premolar restoration.

The Impact of Bonding Agents and Bone Defects on the Fracture Resistance of Reattached Vertically Root-Fractured Teeth

“…Previous research [33] has confirmed that intact teeth have higher fracture resistance than root canaltreated teeth with different core materials. The fracture resistance of the control group was measured to be 1203.66 ± 54.06 N, which is similar to the results reported by Al-Ibraheemi ZA et al [34] and Kaur B et al [35]. The decrease in strength can be attributed to the uneven distribution of stress caused by the endodontic post, which does not effectively balance the load along weakened root walls due to root canal preparation [36].…”

Avaliação da Resistência à Compressão de Materiais Restauradores com Propriedades Bioativas

“…As resinas Filtek (Z350 -3M) apresentam em sua composição o Bisfenol A diglicidil éter dimetacrilato (BisGMA), e assim como os outros materiais os quatro componentes estruturais básicos são: uma matriz polimérica, partículas de carga inorgânica (geralmente vidros de sílica radiopacos), silano e promotores/reguladores da reação de polimerização (Ferracane., 2011), dessa forma justificando a sua alta utilização principalmente em dentes posteriores pois são capazes de resistir à fratura ao receber uma grande quantidade de pressão oclusal (Al-Ibraheemi et al, 2021).…”

Polymerization and shrinkage kinetics and fracture toughness of bulk-fill resin-composites

“…However, Ilie et al suggested reduced light scattering at the filler/matrix interface of BBR and reported some enhanced micro-mechanical properties relative to conventional RBCs [21]. BBR restorations have also been reported to have greater fracture resistance, possibly due to high filler load and elastic modulus [47]. Within OBF, addition-fragmentation monomers may produce more homogeneous network structures to resist fracture stress [14,48].…”