Comparative evaluation of enamel wear against monolithic zirconia and layered zirconia after polishing and glazing: An in vitro study

Abstract

Aim: The aim of this study was to compare the wear behavior of human tooth enamel opposing monolithic zirconia and layered zirconia after glazing and polishing by a two-body wear mechanism using a wear simulator. Settings and Design: This In-vitro study was done in Department of Prosthodontics, Sri Sai College of Dental Research, Vikarabad. Materials and Methods: Zirconia specimens were divided into four groups ( n = 15), Group monolithic glazed zirconia (MG), Group monolithic polished zirconia (MP), Group zirconia layered with E. max ceram and glazed (LG), Group zirconia layered with E. max ceram and polished without glaze (LP). Sixty human premolar teeth were subjected to wear test against the zirconia specimens using a Pin on Disc wear tester under a constant load of 5 kg (49 N) at 30 rpm for 10,000 cycles. The loss of enamel was recorded before and after the wear test and mean loss of height of tooth enamel after 10,000 cycles of wear was measured with a profile projector. The surface characteristics of all the four group zirconia specimens were evaluated qualitatively with scanning electron microscope. Statistical Analysis Used: One way ANOVA, Tukey Post hoc. Results: One-way analysis of variance test revealed that the mean loss of enamel of four groups was statistically different with P < 0.001. A further Tukey post hoc test revealed that the MP group had lesser mean scores than group LP, MG, and LG. Conclusion: It was concluded that MP caused less wear to opposing natural teeth, and polished surfaces of both monolithic and layered zirconia showed less tooth wear compared to glazed surfaces of monolithic and layered zirconia.

Prototype importance for implant supported zirconia bridges: a case report

“…19 An in vitro study conducted by Shaik et al, compare the enamel wear against monolithic zirconia and layered zirconia after polishing and glazing, test results showed that Layered and Glazed group showed significantly greater enamel wear (1.01 mm ±0.11) compared to Monolithic Glazed group (0.76 mm ±0.17), followed by Layered Polished group (0.65 mm ±0.10) and Monolithic Polished group (0.19 mm ±0.08) showed the least enamel wear among the groups tested indicating that the mechanical polishing of zirconia is the best method to reduce the antagonist wear. 20 Providing the provisional prosthesis fabricated directly in the clinic significantly reduces the need for occlusal adjustment in the final definitive prosthesis as the prosthesis is duplicated from the adjusted provisional prosthesis. 21 In this case, the grinding and the adjustment of zirconia were avoided by adjustment of the provisional.…”

Investigation of Wear Behavior in Zirconia All-ceramic Crowns with Varied Surface Treatments Using Scanning Electron Microscopy

“…Ghazal showed that zirconia with different roughness significantly affects the amount of enamel wear [19]. Many scholars have shown that the surface polishing of zirconia produces less wear on natural teeth and less on its own [20][21][22][23][24][25][26][27]. The reason may be that there are a lot of cracks, pores, and other defects on the surface of all ceramic materials without polishing.…”

Lithium disilicate and zirconia as prosthetic restorative materials

“…Minimal antagonist tooth wear is observed, and there is a high success rate for restorations in the posterior region [20] . Polished monolithic zirconia causes less wear to opposing natural teeth, and polished monolithic and layered zirconia surfaces showed less tooth wear compared to glazed monolithic and layered zirconia surfaces [21] . The antagonistic wear of zirconia enamel was similar to or greater than that of natural teeth but less than that of porcelain metal [22] .…”