Wear of Composites by Abrasives of Varying Hardness

The relationship between the wear of three composite resins and the hardness of the abrasive was studied by a two-body abrasion test. The wear rates of the composites increased linearly with abrasive hardness from 530 to 2080 KHN. Measurement of the slope of the wear rate versus abrasive hardness over this range provided a sensitive method for ranking the composites.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68031/2/10.1177_00220345790580031201.pd

Wear of Fluorapatite Single Crystals: III. Classification of Surface Failure

Modes of surface failure observed for natural fluorapatite single crystals under sliding were classified and related to wear and frictional behavior. The basal surfaces exhibited brittle or ductile failure depending on the combination of load and slider design. The transition occurred at penetrations of 0.3 to 0.5 μm.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67122/2/10.1177_00220345720510026101.pd

Wear of Fluorapatite Single Crystals: I. A Method for Quantitative Evaluation of Wear

A quantitative method for characterizing the surface failure of nonmetallic single crystals under sliding was evaluated. It was found that strain rate, load, and slider design influenced the wear of natural fluorapatite single crystals. High loads and slider designs with small radiuses and sharp angles resulted in the deepest penetration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67060/2/10.1177_00220345720510011201.pd

In vitro Wear of Microfilled and Visible Light-cured Composites

Wear of microfilled composites, a visible light-cured composite, and a conventional composite were characterized by two-body abrasion and single-pass sliding. There were differences in abrasion rates among the materials. Tangential forces, wear track widths, and surface failure modes were different among materials. Wear characteristics are combinations of these properties.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67083/2/10.1177_00220345790580111301.pd

Wear of Fluorapatite Single Crystals : V. Influence of Environment on Frictional Behavior and Surface Failure

The influence of environment on the frictional behavior and surface failure of fluorapatite single crystals was evaluated for sliding in air, water, and dimethylformamide. The coefficient of friction was independent of environment. The ductile-to-brittle transition, however, occurred at a lower load in water than in air.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68110/2/10.1177_00220345730520050501.pd

Penetration of Commercial and Dental Waxes

Penetration of commercial and dental waxes was studied. Measurements indicated that resistance of paraffin and dental inlay waxes to penetration was closely related to the temperature at which solid-solid transformations occurred. Annealed waxes were more resistant to penetration than unannealed waxes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67386/2/10.1177_00220345740530023701.pd

Frictional Behavior and Surface Failure of Human Enamel

The frictional behavior and surface failure of human enamel under sliding in water was examined. A large plowing component of friction was observed. For normal loads of up to 1kg, ductile behavior of the wear scar was apparent. Intermittent cracks were obrerved that appeared to propagate around the enamel rods.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67266/2/10.1177_00220345730520063001.pd

Wear of Fluorapatite Single Crystals : IV. Influence of Sliding Direction on Frictional Behavior and Surface Failure

Frictional anisotropy of the basal plane of natural fluorapatite single crystals was observed ; the coefficient of friction (β) in the [2110] direction (β = 0.217) was approximately 12% higher than that in the [0110] direction (β = 0.193). The load at which the ductile-to-brittle transition occurred (Ω) was significantly higher in the [2110] direction (Ω = 77 gm) than in the [0110] direction (Ω = 15 gm). A mechanism is proposed involving the maximum normal stress and probable cleavage planes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67194/2/10.1177_00220345730520050401.pd

Wear of Fluorapatite Single Crystals : VI. Influence of Multiple-Pass Sliding on Surface Failure

The influence of multiple-pass sliding on the surface failure of fluorapatite single crystals was evaluated. The surface and subsurface damage on the basal plane of fluorapatite was accelerative, rather than additive. Damage was more severe for sliding in opposite directions than for two traversals in the same direction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66476/2/10.1177_00220345730520050601.pd

Surface Failure of Commercial and Experimental Restorative Resins

The mode of surface failure of commercial and experimental restorative resins and composites was evaluated with a single-pass sliding test. The wear of restorative resins and composites is determined by the resistance of the material to penetration and by the mode of deformation during sliding.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67209/2/10.1177_00220345760550032201.pd