Mechanical properties of a new core build-up composite resin material

Objective:

This study evaluated mechanical properties (compressive strengths, Vickers hardness, flexural strength and elastic modulus) of a newly developed composite resin core material [ECQ (prototype) (EC; Tokuyama Dental)], compare with 6 existent core materials.

Method:

Three auto-mixing type core materials [EC, DC Core Automix (DCA; KURARAY MEDICAL), Build-IT FR (BU; Pentron)] were tested and compared with two hand-mixing type core materials [DC Core Paste (DC; KURARAY MEDICAL), Unifil Core (UN; GC)] plus two non-mixing type core materials [i-TFC Post Resin (ITP; SUN MEDICAL), i-TFC Core Resin (ITC; SUN MEDICAL)].Compressive strengths were determined using column-shaped specimens (3 mm in height, 4 mm in diameter) stored in water at 37 °C for 24 hours, using a universal testing machine. Flexural strength and modulus of elasticity were determined using bar-shaped specimens (2 x 2 x 25 mm) stored in water at 37 °C for 24 hours, using a universal testing machine. Vickers hardness was determined using disc-shaped specimens (2 mm in height, 10 mm in diameter), using a micro hardness testing machine. All specimens were manipulated according to the manufacturers' instructions. One-way ANOVA, Dunnett's T3 test and Tukey HSD test were used for the statistical analysis (a=0.05).

Results:

EC showed the highest flexural strength (184.3±15.1 MPa). DC (135.4±14.9 MPa) and UN (139.3±18.6 MPa) showed lower flexural strengths than EC, DCA (161.9±9.2 MPa) and BU (161.0±5.7 MPa). ITP showed the lowest elastic modulus (7.3±0.4GPa). EC (401.2±13.6 MPa) showed higher compressive strengths than other auto-mixing type core materials [DCA (343.6±12.2 MPa) and BU (349.7±9.3 MPa) ]. ITP (19.2±1.6) showed the lowest Vickers hardness of all composite resin materials.

Conclusion:

This new prototype ECQ showed the higher mechanical strengths than other auto-mixing composite resins.