A study on thein-vitrowear of the natural tooth structure by opposing zirconia or dental porcelain

Abstract

PURPOSEThis study was conducted to evaluate clinical validity of a zirconia full-coverage crown by comparing zirconia's wear capacity over antagonistic teeth with that of feldspathic dental porcelain.MATERIALS AND METHODSThe subject groups were divided into three groups: the polished feldspathic dental porcelain group (Group 1), the polished zirconia group (Group 2), and the polished zirconia with glazing group (Group 3). Twenty specimens were prepared from each group. Each procedure such as plasticity, condensation, and glazing was conducted according to the manufacturer's manual. A wear test was conducted with 240,000 chewing cycles using a dual-axis chewing simulator. The degree of wear of the antagonistic teeth was calculated by measuring the volume loss using a three-dimensional profiling system and ANSUR 3D software. The statistical significance of the measured degree of wear was tested with a significant level of 5% using one-way ANOVA and the Tukey test.RESULTSThe degrees of wear of the antagonistic teeth were 0.119 ± 0.059 mm3 in Group 1, 0.078 ± 0.063 mm3 in Group 3, and 0.031 ± 0.033 mm3 in Group 2. Statistical significance was found between Group 1 and Groups 2 and between Group 2 and 3, whereas no statistical significance was found between Group 1 and Group 3.CONCLUSIONDespite the limitations of this study on the evaluation of antagonistic teeth wear, the degree of antagonistic tooth wear was less in zirconia than feldspathic dental porcelain, representing that the zirconia may be more beneficial in terms of antagonistic tooth wear.

Wear characteristics of current aesthetic dental restorative CAD/CAM materials: Two-body wear, gloss retention, roughness and Martens hardness

“…3a). As opposed to findings in other laboratory studies (Jung et al, 2010;Preis et al, 2012;Rosentritt et al, 2012) the wear of enamel antagonists by feldspathic ceramic (VM) and glass ceramic (EC) was not significantly different from that of zirconium dioxide ceramics (Tab. 2).…”

“…The zero m-wear for monolithic zirconium dioxide ceramics (IN) and minimal a-wear (25.5 µm) of its enamel antagonists both impressed ( Fig.1; Table 2), even though these properties have already been reported for zirconium dioxide ceramics by recent laboratory studies (Jung et al, 2010;Preis et al, 2012;Rosentritt et al, 2012;Stawarczyk et al, 2012). The contact area of IN looked slightly polished at the end of the test, while, other than the rougher contact areas of the control facets of a-enamel against m-enamel (Fig.…”

Dental ceramics: a review of new materials and processing methods

“…As expected for a composite material, the properties are intermediate between those of ceramics and particle-filled resins. 60,61,63 The elastic modulus of these materials is in the range of 30 GPa, which is half of that reported for conventional veneering ceramics but closer to what is usually reported for dentin (15)(16)(17)(18)(19)(20). 58,63 Typical ceramic materials have a higher elastic modulus values than PICN 64 .…”

“…Some of these studies compared different surface finishing techniques for monolithic zirconia restorations, such as polishing versus glazing, and found that polished surfaces resulted in less enamel wear of the antagonist. 13,14,15,16 It is needless to say that the high surface hardness of zirconia has a major influence on the antagonist wear and a perfect polish of any monolithic zirconia restoration is therefore very important. A clinical study evaluated the occlusal surface wear of monolithic zirconia crowns placed in premolars and molars.…”

Microleakage and penetration depth of different fissure sealant materials after cyclic thermo-mechanic and brushing simulation

“…Buccal cusps of extracted upper premolar teeth were sectioned and used as an antagonist in a chewing simulation. For oneyear, thermo-mechanic simulation, 240,000 load cycles with a load of 49 N and a frequency of 1.7 Hz, were applied through 1.5 mm horizontal and 3 mm vertical movement of the antagonist on the center of the sealed occlusal surfaces 13) . Specimens were also subjected to thermocycling (1,000 cycles of 5 and 55°C; 100 s per cycle, and a 10-s interval to remove water from the chambers) at the same time with the chewing simulation.…”