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Purpose: Composite resin teeth are more widely used than porcelain or acrylic resin teeth in the fabrication of removable dentures because of their high fracture toughness and high abrasion resistance. The purpose of this study was to evaluate the shock absorbability of commercially available artificial posterior teeth by the free drop--ball test with an accelerometer and to evaluate the Vickers hardness at the surface. Materials and Methods: The tested artificial teeth included seven composite resin teeth, one acrylic resin tooth, and one porcelain tooth. Specimens were tested 50 hours after immersion in distilled water at 37°C. The impact value and Vickers hardness were measured. A one-way analysis of variance was used to analyzed the data (P = .05). Results: The composite resin teeth showed an intermediate impact value between that of the acrylic resin tooth and the porcelain tooth. Among the artificial teeth investigated, the porcelain tooth showed the highest impact value. A significant difference in the impact value was observed between the porcelain tooth and the composite resin and acrylic resin teeth. However, no significant difference was observed among the composite resin teeth tested. A significant correlation was found between the impact values and the Vickers hardness of the artificial teeth. Conclusion: The present findings suggest that composite resin teeth and acrylic resin teeth have a higher shock absorbability than porcelain teeth. [ABSTRACT FROM AUTHOR]

Recently a new generation of laboratory-processed composite resins containing submicron glass fillers was introduced, with claims of high strength. The purpose of this study was to evaluate the effect of thermal cycling in water on the flexural strength and hardness of several laboratory composite systems. The flexural strength of the new laboratory processed composite resins (Artglass [AG], Targis [TR] and Estenia [ES]) was significantly higher than that of conventional resins (Dentacolor [DC] and Cesead II [CS]). Thermocycling caused a reduction of the flexural strength but not a reduction of the hardness for most of materials tested. It was concluded that thermocycling affected the properties of the laboratory-processed hybrid type composite resin, ES, AG and TR. However, the changes of these properties were smaller than those of microfine type composite resin DC. Thus, ES, AG and TR may maintain better properties during service compared with DC. [ABSTRACT FROM AUTHOR]

The article presents a clinical study on evaluating the shock absorbability between high-abrasion-resistance-posterior resin teeth and commercial porcelain teeth in Japan. A free drop-ball test with an accelerometer was used to test the shock absorbability of commercially available posterior teeth. Several results include the maximum acceleration of porcelain teeth than resin teeth, porcelain teeth shows the shortest duration, and resin teeth shows excellent resistance impact force.

The article discusses a study conducted by several Japanese researchers which examines the impact of surface treatments on the shear bond strength between abrasion resistance plastic teeth and photo-cured dental resin. Findings reveal that the bond strength of dried corrasion-resistant synthetic teeth to photo-cured resin was better than water concentrated one. It also notes that the treatment with silane couping agent, bonding agent and methylene chloride did not increase shear bond strength.