The Role of Home Bleaching Agent on the Fracture Toughness of Resin Composites Using Four-Point Bending Test
Journal Title: Journal of Dental Biomaterials - Year 2014, Vol 1, Issue 1
Abstract
Statement of Problem: Resin composites are a common type of tooth coloured restorative materials. These materials are brittle and their major shortcomings are sensitivity to flaws and defects, low tensile strength, and susceptibility to catastrophic failure.The role of home bleaching agents on the fracture toughness of resin composites using four-point bending test is scanty. Objectives: To compare the fracture toughness (KIc) of resin composites on a fourpoint bending test and to assess the effect of distilled water and a home bleaching agent on the resistance of the materials to fracture. Materials and Methods: seventy-two bar-shaped specimens were prepared from three materials: Rok (SDI), Estelite (Tokuyama), and Vit-l-escence (Ultradent) and divided into three groups. Two groups were assigned as “control” and conditioned in distilled water at 37oC for 24 hours or 21 days, respectively. The specimens in the third group (treatment) were stored in distilled water for 21 days and bleached using Polanight (SDI) for 2 hours daily. For each material, a total of 24 disc-shaped specimens were prepared and after each time interval loaded in a four-point bending test using a universal testing machine with a crosshead speed of 0.5 mm/m. The maximum load to specimen failure was recorded and the KIc was calculated. Results: Statistical analysis using two-way ANOVA showed a significant relationship between materials and treatment (P<0.05). Tukey’s test showed that after 24 hours of immersion in distilled water, KIc was not significantly different between materials; Rok revealed the highest value followed by Estelite and Vit-l-escence. The bleaching agent significantly decreased the KIc values of Estelite and Rok while it did not affect that of Vita-l-escence. Immersion in distilled water for all resin composites caused a significant decrease in KIc. Conclusion: The fracture toughness of the resin composites was affected by the bleaching agent and 21day immersion in distilled water.
Authors and Affiliations
M Ghazvini Ferooz, N Azadeh, MR Azar
Keywords
Related Articles
- EP ID EP248943
- DOI -
- Views 85
- Downloads 0
Effect of Caries Removal Methods on the Shear Bond Strength of Resin and Glass IonomerAdhesives to Primary Dentin
Statement of Problem: There is no enough published data about the shear bond strength of resin modified glass ionomer adhesives on caries-affected primary tooth dentin excavated using minimally invasive systems. Objectiv...
Comparison of Microtensile Bond Strength of Silorane-Based Composite with the Conventional Methacrylate Composite to the Dentin of Primary Teeth
Statement of Problem: The bond strength between restorative material and tooth structure is so important for conduction of durable restoration. Considering the recent attention to low shrinkage composite resins, evaluati...
Modification of a Soft Drink by Adding Calcium Carbonate Nanoparticles to Prevent Tooth Erosion
Statement of Problem: One of the factors in dental erosion is consumption of acidic soft drinks. Although the effects of various additives to acidic soft drinks for the prevention of tooth erosion have been assessed, lit...
Effect of Combined Calcium Hydroxide and Accelerated Portland Cement on Bone Formation and Soft Tissue Healing in Dog Bone Lesions
Statement of Problem: Recent literatures show that accelerated Portland cement (APC) and calcium hydroxide Ca (OH)2 may have the potential to promote the bone regeneration. However, certain clinical studies reveal consis...
Colour Stability of Various Types of Acrylic Teeth Exposed to Coffee, Tea and Cola
Statement of Problem: Acrylic teeth of dentures are prone to discoloration due to frequent exposure to different colouring solutions in the oral environment. Thus, in order to maintain their aesthetic appearance, they mu...