Study of abrasive resistance of composites for dental restoration by ball-cratering

Two-body abrasion occurs in the mouth whenever there is tooth-to-tooth contact. This is what most dentists call attrition. Abrasive wear may also occur when there is an abrasive slurry interposed between two surfaces, such that the two solid surfaces are not actually in contact, this is called three-body abrasion, with food acting as the abrasive agent, and occurs in the mouth during mastication. Abrasion is the key physiological wear mechanism that is present in dental materials during normal masticatory function. The two main categories of restoration materials are dental amalgam and composite restorative material. Although amalgam has excellent mechanical properties, it also has certain limitations and disadvantages. The main negative factors for amalgam are: aesthetic factor, toxicity of mercury, weak adhesion to healthy dental tissue, duration of restoration, corrosion and feeble resistance to fracture. One of the main objectives in wear studies is to determine the nature of the dependency between the mechanical properties of materials and their tribological behaviour of the surfaces in contact. The aim of the present work is to study the effect of cure conditions on light curable composites on hardness and the respective abrasion resistance. Six commercially available composite restorative materials used for posterior restorations were selected for the study. In order to obtain comparative results one amalgam has been included in the study. The technique of bail-cratering is used to evaluate the resistance to abrasion. (C) 2003 Elsevier Science B.V. All rights reserved.