OBJECTIVE: The goal of this program was to identify promising environments that could efficiently minimize machining-induced damage of dental materials. METHODS: Single point abrasion (SPA) scratch testing was used on five materials to determine the @entity3358 and amount of edge chipping as functions of chemical environment, including air, water, saline and @entity653 solutions. Limited testing was also done under additional environments expected to promote chemomachining effects via crack growth promotion or debris removal. A conical diamond indenter and a conventional @entity45480 machining tool were used in the scratch tests. One-way ANOVA analysis was used to determine statistical differences among the variables. RESULTS: There was a consistent trend across materials that the water and saline yielded the lowest values of @entity3358 , air the next lowest, and the tests performed in @entity653 yielded the highest hardness values. The measured hardness values using the conical diamond tool in the @entity653 environments were about twice the hardness values measured under water and saline solutions. Environmental effects on chipping were minimal, but a linear relationship between load and per cent chipping was determined for the WC tool within the 10-50 N test range. The choice of scratch tool strongly affected @entity3358 and chipping tendency. SIGNIFICANCE: The chemical environment had an effect on machining characteristics, but the effects were more dependent on tool interactions rather than material specific properties. As a result, it may not be possible to utilize a particular single environment to substantially improve the damage response of dental materials to machining operations. Improvements in damage resistance can be environmentally obtained, but only for shallow cuts (finishing operations).

XXXX and chipping of dental ceramics under different environments.

@entity45480 :: ('MESH:C002802', 'Chemical') :: ['tungsten carbide'] @entity3358 :: ('MESH:D018804', 'Disease') :: ['scratch hardness'] @entity653 :: ('MESH:D005990', 'Chemical') :: ['glycerol']
@entity3358 :: (MESH:D018804,Disease) :: ['Scratch hardness']
