Flexural Strength of Various Provisional Restorative Materials for Rehabilitation After Aging

Abstract

Durability of provisional restoration is crucial for full-mouth reconstruction, which may be influenced by aging. This study evaluated the effect of aging on the flexural strength of provisional materials for oral rehabilitation. Materials and methods: Bar specimens (2×2×25 mm) were fabricated from CAD-CAM [Vita CAD-Temp ® (VC), Telio ® CAD (TC), artBloc ® (RC)], autopolymerized [Protemp™IV (PA), Luxatemp ® (LA), Unifast™Trad (UA)], and heat-polymerized polymer [Major ® C & B; (MH)]. Each was divided into aging (AG, 5000 thermocycles of 5 • /55 • C) and nonaging groups (NG, n = 15/group). Flexural strength (σ, MPa) was determined in a universal testing machine at 1 mm/min crosshead speed. An analysis of variance and multiple comparisons were determined for significant difference (α = 0.05). Results: TCNG indicated the highest mean of σ (133.49 ±4.32), whereas VCNG indicated the lowest mean of σ (84.62 ±3.73) for nonaging. Upon aging process, TCAG revealed the highest mean of σ (123.11 ±4.55), while VCAG possessed the lowest mean of σ (84.05 ±6.39). Significant differences among various provisional materials were indicated (p = 0.001). Aging significantly affected flexural strength (p = 0.001). Conclusions:The CAD-CAM provisional material possessed higher flexural strength than heat-polymerized PMMA and autopolymerized PMMA, which was suggested as a provisional material for rehabilitation. Aging reduced strength for all materials tested.

Influence of Artificial Aging on the Vickers Hardness of Milled and 3D Printed Provisional Materials

“…For PR, the specimens were also virtually designed with less free monomer and lower porosity, in addition to lower water absorption and less solubility [3,[7][8][9]22]. All of these factors might reduce the plasticizing effects of milled resins.…”

“…The development and application of CAD-CAM technology has also promoted important changes in the production of transitory restorations. Characterized by greater speed, efficiency and quality control the CAD/ CAM fabrication process has been adopted using either subtractive manufacturing or additive manufacturing technologies [7].…”