Abrasion resistance of veneering materials to tooth brushing.
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This study was carried out to comparatively examine abrasion which occurred as a result of brushing as well as abrasives in veneering materials used in prosthetic restorations. Twenty out of forty specimens prepared at the dimensions of 14x5x3 mm, there being ten specimens of each veneering materials, were subjected to tooth brushing with water alone. The other twenty specimens were subjected to a tooth brushing procedure with a paste- water mixture with the aim of evaluating the effects of abrasives on abrasion. As a result, it was statistically determined that porcelain, an ideal facet material, had the best resistance to abrasion by toothbrush, light cured aesthetic materials being second Poly methyl methacrylate had the least abrasion resistance. (+info)
Abrasive effect of brushing on ormocers following acid conditioning.
(10/56)
The purpose of this study was to evaluate the effect of toothbrushing on the surface roughness and microhardness of Admira and Definite following acid conditioning. Half of the samples were either used as controls or brushed for 10 minutes using an electric toothbrush with slurry. The remaining specimens were stored in orthophosphoric acid with a pH of 1.9 for 24 hours and then half were brushed. The surface roughness of Admira and Definite was not significantly affected by storage under acidic conditions. However, the specimens of both materials in the control groups and the ones tested after acidic storage were found to be significantly smoother than the specimens subjected to toothbrushing alone and brushing following acid conditioning. For both materials, significantly higher values of microhardness were obtained after toothbrushing following acid conditioning than toothbrushing alone. Therefore, brushing following acid conditioning significantly affects the surfaces of the ormocers. (+info)
Optical and color stabilities of paint-on resins for shade modification of restorative resins.
(11/56)
The purpose of this study was to examine the optical and color stabilities of the paint-on resin used for shade modification of restorative resins. Three shades of paint-on resin and two crown and bridge resins were used. The light transmittance characteristics of the materials during accelerated aging tests such as water immersion, toothbrush abrasion, ultraviolet (UV) light irradiation, and staining tests were measured. Discolorations of materials resulting from tests were also determined. There were no significant effects of water immersion, toothbrush abrasion and UV light irradiation on the light transmittance and visible color change of paint-on resins, whereas the staining tests significantly decreased the light transmittance and increased color change of the translucent shades of materials. Our results indicate that the paint-on resins exhibit stable optical properties and color appearance, which are at least as good as the crown and bridge resins. (+info)
Effects of occlusal and brushing forces on wear of composite resins.
(12/56)
Effects of occlusal and brushing forces on the wear of composite resins were investigated using three different wear tests: simulated occlusal wear test, toothbrush wear test, and combined wear test which carried out toothbrush wear test and occlusal wear test alternately. Test specimens were prepared from four commercial composite resins. Worn volume and maximum worn depth were measured under different occlusal forces (40 N and 80 N) and brushing forces (1.5 N and 3 N) in the three wear tests. Worn surfaces were observed using a SEM. In all the three wear tests, both higher occlusal and brushing forces resulted in significantly greater worn volume and higher maximum worn depth. The effects of occlusal force on worn volume and maximum worn depth varied with different composites, indicating that the four tested composites showed different wear behaviors under different occlusal forces and brushing forces. It was suggested that their different wear behaviors most probably stemmed from the differences in their filler systems. (+info)
Evaluation of wear and subsequent dye penetration of endodontic temporary restorative materials.
(13/56)
This study evaluated the wear resistance and sealing property of endodontic temporary restoratives by means of functional stressing using a wear simulator. The pulp chamber of 28 extracted molars was opened and filled with cotton, and then the cavity was filled with a temporary material--Caviton, Temporary Pack, Neodyne-alpha, or TERM. Specimens were subjected to a wear test, and data for wear and dye penetration were analyzed by one-way ANOVA independently (p < 0.05). Wear values of Neodyne-alpha (0.09 +/- 0.05 mm) and TERM (0.24 +/- 0.06 mm) were significantly less than those of Caviton (1.79 +/- 0.15 mm) and Temporary Pack (1.02 +/- 0.40 mm). In terms of dye penetration, Neodyne-a leaked significantly less than the other materials at 0.40 +/- 0.32 mm. On the other hand, there were no significant differences between TERM (1.30 +/- 0.57 mm) and Temporary Pack (2.10 +/- 0.12 mm), and between Caviton (2.60 +/- 0.41 mm) and Temporary Pack. (+info)
Effect of ceramic coating by aerosol deposition on abrasion resistance of a resin composite material.
(14/56)
Aerosol deposition (AD coating) is a novel technique to coat solid substances with a ceramic film. The purpose of the present study was to investigate the effect of AD coating on abrasion resistance of a resin composite material. A 5-microm-thick aluminum oxide layer was created on the polymerized resin composite. The specimen was cyclically abraded using a toothbrush abrasion simulator for 100,000 cycles. Abraded surface was then measured with a profilometer to determine the average roughness (Ra) and maximum roughness (Rmax). It was found that abrasion cycling increased the Ra value of the No-AD-coating group, but decreased the Ra and Rmax values of the AD coating group. Moreover, the AD coating group showed significantly smaller Ra and Rmax values after 100,000 abrasion cycles as compared to the No-coating control group. Microscopic observation supported these findings. In conclusion, the resistance of the resin composite against toothbrush abrasion was improved by AD coating. (+info)
Effect of a metal priming agent on wear resistance of gold alloy-indirect composite joint.
(15/56)
The purpose of the current study was to evaluate the effect of a metal priming agent on wear resistance of gold alloy-composite joint. Four types of plate specimen were prepared: composite (Estenia C&B or Epricord) alone, type 4 gold alloy alone, alloy-composite joint without priming agent, and alloy-composite joint bonded with a priming agent (Alloy Primer). Three-body wear test was performed using the plate specimens, gold alloy antagonist, and polymer slurry. Joined specimens with priming exhibited less wear depth (in microm; 21.0 for Estenia and 24.9 for Epricord) than the joined specimens without priming (57.8 for Estenia and 46.7 for Epricord). Wear depth of the single plate specimens when abraded with the gold alloy antagonist was ranked as follows: Estenia (9.6), gold alloy (12.8), and Epricord (19.1). It was concluded that the use of a metal priming agent at the alloy-composite interface effectively enhanced the wear resistance of the joined area when under cycled loading. (+info)
Surface carbonization of titanium for abrasion-resistant implant materials.
(16/56)
Carbide layer was formed on the surface of Ti by heating in hydrocarbon atmosphere (benzene C6H6) at 1000-1400 degrees C using a high frequency induction heating method. Physical and mechanical properties of carbide-coated Ti were investigated to examine its potential as an abrasion-resistant implant material. Scanning electron microscopy (SEM) showed that the surface of Ti was covered with fine grains of 1-4 microm diameter, depending on heating conditions. In addition, carbide layer of about 1-25 microm thickness was observed on the cross-section of specimens by SEM and energy dispersive spectroscopy. Vickers hardness of surface carbide was found to be more than 2000. Further, Martens scratch test and ultrasonic scaler abrasion test showed that the indentation depth and width of carbide-coated Ti were much smaller than pure Ti, thereby confirming its high abrasion resistance. These results showed that for Ti implant materials that require high abrasion resistance, such as the abutment for dental implants, surface carbide coatings would be an effective means to improve their wear properties. (+info)