IADR Abstract Archives
Fracture Toughness of Dental Provisional Materials
Objectives: Provisional restorations used in the interim between tooth preparation and placement of the final restoration are valuable and necessary for a successful treatment. As one of the most important properties of a dental material, fracture toughness (KIC ) describes the ability to resist fracture. Tougher materials indicate a greater ability to resist crack growth and are in turn more reliable. The objective of this study was to measure the fracture toughness of four different dental provisional materials to better understand their ability to resist fracture.
Methods: Four provisional materials (Luxatemp Star, DMG; Structur 3, Voco; Protemp 4, 3M Oral Care; Tempsmart, GC) were evaluated for fracture toughness (KIC) in the single-edge-V-notch-beam (SEVNB) configuration. All samples (n=12-15) were prepared in accordance with ISO 13586 and self-cured in a custom mold (2.5 x 5 x 25mm), notched (depth 0.45-0.55mm), stored (37°C, 14d), tested (3-point bending, 10mm/min), and KIC analyzed (ANOVA, Tukey’s, p<(0.05). An additional group of Tempsmart was subjected to stepwise light-curing (5 spots, 5s) after self-curing according to manufacturer recommendations.
Results: The KIC values (means and (S.D.)) in MPa.m0.5 are as follows: Luxatemp Star, 0.91(0.04); Structur 3, 0.89(0.05); Protemp 4, 1.15(0.03); Tempsmart, 1.14(0.02); and Tempsmart with light-curing, 1.25(0.05). Tempsmart processed with an additional light-curing step had the significantly highest fracture toughness. Without the additional light-curing step, Tempsmart had a statistically similar KIC value to the material Protemp 4. Both Luxatemp Star and Structur 3 showed statistically equivalent KIC values but significantly lower than all other materials.
Conclusions: Tempsmart and Protemp 4 significantly resist fracture over the other materials, while Tempsmart with an additional light-curing step had the significantly highest fracture toughness.
Methods: Four provisional materials (Luxatemp Star, DMG; Structur 3, Voco; Protemp 4, 3M Oral Care; Tempsmart, GC) were evaluated for fracture toughness (KIC) in the single-edge-V-notch-beam (SEVNB) configuration. All samples (n=12-15) were prepared in accordance with ISO 13586 and self-cured in a custom mold (2.5 x 5 x 25mm), notched (depth 0.45-0.55mm), stored (37°C, 14d), tested (3-point bending, 10mm/min), and KIC analyzed (ANOVA, Tukey’s, p<(0.05). An additional group of Tempsmart was subjected to stepwise light-curing (5 spots, 5s) after self-curing according to manufacturer recommendations.
Results: The KIC values (means and (S.D.)) in MPa.m0.5 are as follows: Luxatemp Star, 0.91(0.04); Structur 3, 0.89(0.05); Protemp 4, 1.15(0.03); Tempsmart, 1.14(0.02); and Tempsmart with light-curing, 1.25(0.05). Tempsmart processed with an additional light-curing step had the significantly highest fracture toughness. Without the additional light-curing step, Tempsmart had a statistically similar KIC value to the material Protemp 4. Both Luxatemp Star and Structur 3 showed statistically equivalent KIC values but significantly lower than all other materials.
Conclusions: Tempsmart and Protemp 4 significantly resist fracture over the other materials, while Tempsmart with an additional light-curing step had the significantly highest fracture toughness.