Flexural Strength of Various Provisional Restorative Materials for Rehabilitation After Aging

Purpose: 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 (2x2x25 mm) were fabricated from CAD-CAM [Vita CAD-Temp (R) (VC), Telio (R) CAD (TC), artBloc (R) (RC)], autopolymerized [Protemp (TM) IV (PA), Luxatemp (R) (LA), Unifast (TM) Trad (UA)], and heat-polymerized polymer [Major (R) C & B; (MH)]. Each was divided into aging (AG, 5000 thermocycles of 5 degrees/55 degrees C) and nonaging groups (NG, n = 15/group). Flexural strength (sigma, 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 (alpha = 0.05). Results: TCNG indicated the highest mean of sigma (133.49 +/- 4.32), whereas VCNG indicated the lowest mean of sigma (84.62 +/- 3.73) for nonaging. Upon aging process, TCAG revealed the highest mean of sigma (123.11 +/- 4.55), while VCAG possessed the lowest mean of sigma (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.