Randomized clinical study of wear of enamel antagonists against polished monolithic zirconia crowns

Abstract

Objectives To test the hypothesis that there is no difference in the in vivo maximum wear of enamel opposing monolithic zirconia crowns, enamel opposing porcelain fused to metal crowns and enamel opposing enamel. Methods Thirty patients needing single crowns were randomized to receive either a monolithic zirconia or metal-ceramic crown. Two non-restored opposing teeth in the same quadrants were identified to serve as enamel controls. After cementation, quadrants were scanned for baseline data. Polyvinylsiloxane impressions were obtained and poured in white stone. Patients were recalled at six-months and one-year for re-impression. Stone models were scanned using a tabletop laserscanner to determine maximum wear. Statistical analysis was performed using Mann-Whitney U to determine any significant differences between the wear of enamel against zirconia and metal-ceramic crowns. Results Sixteen zirconia and 14 metal-ceramic crowns were delivered. There were no statistical differences in mean wear of crown types (p = 0.165); enamel antagonists (p = 0.235) and enamel controls (p = 0.843) after one year. Conclusion Monolithic zirconia exhibited comparable wear of enamel compared with metal-ceramic crowns and control enamel after one year. Significance This study is clinically significant because the use of polished monolithic zirconia demonstrated comparable wear of opposing enamel to metal-ceramic and enamel antagonists.

Effect of sintering duration on the sliding‐wear resistance of 3Y‐TZP dental ceramics

“…Subsurface microcracks may propagate toward the surface, where they become visible ( Figure 8B). 34,35 The observation of both plastic deformation and fracture wear mechanisms is consistent with the value obtained for the specific wear rate, which was at the boundary between mild and severe wear, since plastic deformation alone is typically associated with mild wear, and fracture with severe wear. The coalescence of subsurface cracks leads to the formation of dislodged wear particles, which produce the observed pits upon ejection (ie, particle pullout), adjacent to the scratches.…”

“…18,25,[31][32][33] Such spalling is particularly deleterious, since the greater surface roughness of the exposed regions may also damage the counterbody-in the oral cavity this can result in wear of antagonist teeth. 34,35 The observation of both plastic deformation and fracture wear mechanisms is consistent with the value obtained for the specific wear rate, which was at the boundary between mild and severe wear, since plastic deformation alone is typically associated with mild wear, and fracture with severe wear. Similar wear mechanisms during sliding of zirconia have been reported by other researchers under comparable test conditions.…”

Comprehensive analysis of laserscanner validity used for measurement of wear

“…The ideal dental material is one that will wear the same rate as natural enamel, will not cause undue harm to the surrounding tissues or accelerate the wear of the opposing enamel. Various assessment techniques and devices have been used to evaluate the wear of dental hard tissue and dental restorative surfaces in vitro and in vivo . However, since wear is caused by a combination of factors which are difficult to simulate in vitro, most of these tests are not representative of the wear that occurs intra‐orally.…”

“…A divet or a landmark is used to allow identification of the area of interest for wear measurement. Laserscanners or micro computerised tomography scanners using superimposition software or surface profilometers are then used to quantify wear.…”

Relation Between Clinical Oral Health Status, Oral Health Related Quality of Life, Denture Material Type and Self-perceived General Health, in a General Population

“…The fabrication of both fixed and removable dentures implies the usage of various materials. In respect to the fixed dentures, single-tooth crowns or partially fixed dentures currently benefit from the properties of dental ceramics, in both their porcelain fused to metal and, more often, full ceramic version [36,37]. Full ceramic systems are constantly evolving, with the purpose of providing enhanced combined strength and optical properties, in either heat-pressed [38] or milled forms [39].…”