Wear characteristics of polished and glazed lithium disilicate ceramics opposed to three ceramic materials

Abstract

This study compared the wear characteristics of a heat-pressed lithium disilicate ceramic material opposed to feldspathic porcelain, a lithium disilicate glass ceramic, and zirconia materials. Ceramic plate specimens were prepared from feldspathic porcelain (EX-3 nA1B), lithium disilicate glass ceramics (e.max CAD MO1/C14), and zirconia (Katana KT 10) and then ground or polished. Rounded rod specimens were fabricated from heatpressed lithium disilicate glass ceramic (e.max press LT A3) and then glazed or polished. A sliding wear testing apparatus was used for wear testing. Wear of glazed rods was greater than that of polished rods when they were abraded with ground zirconia, ground porcelain, polished porcelain, or polished lithium disilicate ceramics. For both glazed and polished rods, wear was greater when the rods were abraded with ground plates. The findings indicate that application of a polished surface rather than a glazed surface is recommended for single restorations made of heat-pressed lithium disilicate material. In addition, care must be taken when polishing opposing materials, especially those used in occlusal contact areas. (J Oral Sci 58, 117-123, 2016)

Tribological Behavior Simulation of Ceramic Material Using the Finite Element Analysis

“…It is known that von Misses stress will always follow the path of the harder material, with a higher modulus of elasticity. In our case, the harder material is ceramic, and the occlusal load will be transmitted to the underlying dental tissues, the load being dissipated down to the root, radial and apical, which explains, moreover, the degree of damage of the affected tooth [4][5][6][7][8][9].…”

Wear assessment of current aesthetic crowns compared with human enamel after two finishing procedures: In vitro study

“…The wear may affect the thickness of the restoration and the natural enamel, which impairs the esthetic appearance and limits tooth survival rates 3,4 . Recent studies suggest that surface roughness highly influences o tooth wear 5 . A smooth ceramic surface enhances the function and aesthetics of teeth, and prevents gingival inflammation and the accumulation of stains and plaque on the surface of a restoration 6 , while a rough surface may abrade natural teeth, which compromises the appearance of the restoration 7 .…”

Wear Behavior of Ceramic CAD/CAM Crowns and Natural Antagonists

“…Full-contour CAD/CAM ceramic crowns are currently used and are a relatively new restoration method in the prosthodontic. There are different types of CAD/CAM block ceramic-glass-polymer materials [4] with different compositions and physical properties: IPS empress leucite ceramic, e.max press lithium disilicate ceramic [5], lithium disilicate glass-ceramic [6,7,8], Y-TZP ceramic [9], heat-pressed lithium disilicate ceramic, feldspathic porcelain, glass ceramic [2,10], zirconia, lithium disilicate, feldspathic ceramic [11], nanoceramic [4], resin nanoceramic [4,6], zirconia-reinforced lithium silicate ceramic (Vita Suprinity) [7], and polymer infiltrated ceramic network (PICN) materials, also called hybrid ceramics [4,12] or glass ceramic in a resin interpenetrating matrix (Vita Enamic) [13]. Gracis et al (2015) created a classification system for dental ceramic materials that is useful for communication and educational purposes [13].…”

“…The occlusal surface roughness and smoothness of ceramic crowns are clinically important because these parameters have an impact on the plaque accumulation, wear kinetics, staining, the tactile perception of the patient [16], shade matching [12], and the wear of opposing natural teeth and opposing materials [8]. The wear of the ceramic crown occlusal surface can cause systemic effects if particles from the restorations are swallowed or inhaled [5]; the wear can also impact the thickness of the occlusal part of the full ceramic CAD/CAM crowns and the natural antagonists [2], which can lead to the occlusion change and an impaired aesthetic appearance and/or functional restrictions [5,17].…”

“…There are many factors that influence the surface roughness and wear of restorative materials and the natural antagonists, such as the finishing [12] and polishing or glazing quality [8,9] of the occlusal surfaces of the CAD/CAM manufactured ceramic crowns, the flexural strength, modulus of resilience [15] and the solubility [20,21] of the ceramic materials, chewing with a different frequency, force of mastication, force profile, contact time, sliding movement, clearance of worn material [5], the hardness of food, pH of the saliva [22], gastroesophageal reflux disease [23], and toothbrushing [24]. …”