Comparative evaluation of natural enamel wear against polished yitrium tetragonal zirconia and polished lithium disilicate - An in vivo study

Antagonist enamel tooth wear produced by different dental ceramic systems: A systematic review and network meta-analysis of controlled clinical trials

OBJECTIVES

The aim of this study was to evaluate the amount of enamel tooth wear induced by different antagonistic ceramic crown materials in the posterior area within a follow-up period up to 24 months in function. A network meta-analysis was performed to assess the effect of the materials on the mean vertical loss (MVL) of the antagonist enamel tooth surface.

DATA

Main search terms used in combination: ceramic, dental materials, metal ceramic, tooth wear and dental enamel.

SOURCES

An electronic search was conducted in PubMed/Medline, Embase, and Cochrane CENTRAL plus hand-searching.

STUDY SELECTION

Eligibility criteria included clinical studies reporting on MVL on antagonist's tooth up to 24 months following the permanent crown placement. From a total of 5697 articles, 7 studies reporting on 261 crowns for 177 subjects with 3 ceramic materials (Lithium disilicate, metal-ceramic, monolithic zirconia) were included. Among all, metal-ceramic and zirconia caused significantly higher enamel tooth wear on antagonist teeth, representing 82.5 µm [54.4; 110.6]) and 40.1 µm [22.2; 58.0]) more MVL than natural teeth group. In contrast, lithium disilicate showed only 5.0 µm [-48.2; 58.1]) more MVL than occurs on opposing natural teeth.

CONCLUSIONS

This systematic review demonstrated that prosthodontic ceramic materials produced significantly more antagonist enamel tooth wear than opposing natural enamel tooth wear, and ceramic material type was correlated to the degree of enamel tooth wear. Additional well-conducted, randomized controlled trials with homogeneous specimens are required due to inadequate sample size and number of the clinical studies included in the analyses.

CLINICAL SIGNIFICANCE

The amount of wear caused by different restorative materials has a high influence on the antagonistic natural teeth and should therefore be evaluated intensively by the dentist.

Wear characteristics of esthetic resin matrix and zirconia reinforced lithium disilicate CAD/CAM materials: two-body wear and surface topography analysis

BACKGROUND

This in vitro study assessed the wear behavior of different CAD-CAM blocks and the abrasion of the enamel antagonist against these materials.

METHODS

64 disk-shaped specimens were prepared from 8 different CAD/CAM blocks as follow: one lithium disilicate glass ceramics block "IPS Emax CAD" as control group, two zirconia reinforced lithium silicate "Vita Suprinity & Celtra DUO," one interpenetrating network ceramic block "Vita Enamic," Three resin-based block composites "Lava Ultimate, Cerasmart & Brilliant-crios" as well as one hybrid nanoceramic "Shofu block HC". All specimens were mounted against canine and tested for two body wear analysis using a chewing simulating loading machine (100,000 cycles, 50 N, 5/55 °C). The amount of wear loss was measured for each specimen using a digital precise scale. Wear area before and after the chewing simulation were evaluated using an optical profilometer. Data analysed using one-way ANOVA test followed by Tukey's post hoc.

RESULTS

The results showed a significantly higher wear loss in resin matrix ceramics in comparison to glass ceramics. However, for tooth wear glass ceramics had significantly higher value than hybrid ceramics.

CONCLUSIONS

Resin based CAD/CAM Blocks gives a superior result when evaluating the wear behavior and its effect on the opposing tooth surface.

Enamel Wear of Antagonist Tooth Caused by Dental Ceramics: Systematic Review and Meta-Analysis

BACKGROUND

This systematic review and meta-analysis aimed to evaluate the wear of the antagonist tooth in ceramic restorations.

MATERIAL AND METHODS

This study was carried out based on Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) recommendations; it was also registered in PROSPERO (register number: CRD42022316252). Three databases were consulted in the literature search, Embase, Scopus, and Web of Science. The citation searching was conducted by two researchers independently. The clinical studies that evaluated wear in antagonist teeth concerning ceramic restoration were included. Twelve articles were selected after eliminating duplicates ones and applying the inclusion criteria, and two were chosen through citation. Fourteen articles were considered for the qualitative and quantitative analysis (meta-regression and meta-analysis).

RESULTS

The mean linear wear of the antagonist tooth in relation to feldspathic was 8.914 μm, for lithium disilicate it was 0.018 μm, and for zirconia it was 0.257 μm. The mean volumetric wear of the antagonist tooth in relation to feldspathic was 0.273 mm3, for hybrid ceramic it was 0.030 mm3, for lithium disilicate it was 0.018 mm3, and for zirconia it was 0.014 mm3. The mean natural tooth wear was 0.7974 μm per month. Tooth wear caused by zirconia at six months was 31.755 μm, at 12 months it was 24.648 μm, and at 24 months it was 20.662 μm.

CONCLUSIONS

Feldspathic produces greater wear of the antagonist tooth from ceramic restorations linearly and volumetrically. In addition, zirconia generates the least wear that will decrease over time, and it will be equal to or less than the natural wear in the tooth.

Evaluation of wear behavior of dental restorative materials against zirconia in vitro

OBJECTIVES

To evaluate two-body wear (2BW) and three-body wear (3BW) of different CAD/CAM and direct restorative materials against zirconia using a dual-axis chewing simulator and an ACTA wear machine.

METHODS

3 CAD-CAM resin-based composite or polymer infiltrated ceramic network blocs, 1 lithium disilicate CAD-CAM ceramic (LS₂), 3 direct resin composites, amalgam and bovine enamel were tested. For 2BW, 8 flat specimens per material were produced, grinded, polished, stored wet (37 °C, 28d) and tested (49 N, 37 °C, 1,200,000 cycles) against zirconia. For 3BW, specimens (n = 10) were stored accordingly, and tested against a zirconia antagonist wheel (3Y-TZP, d = 20 mm, h = 6 mm; 200,000 cycles, F = 15 N, f = 1 Hz, 15% slip) in millet seed suspension. Wear resistance was analysed in a 3D optical non-contact profilometer, measuring vertical wear depth and volume loss for 2BW and mean wear depth and roughness (R_a) for 3BW. Vickers hardness (15 s, HV2) was measured. Statistical analysis was performed using non-parametric tests (Mann-Whitney-U test, p < 0.05).

RESULTS

2BW and 3BW have a different impact on material surfaces. Similar wear resistance was observed for direct and indirect resin based materials with analogous filler configurations in both methods. Bovine enamel exhibited the best wear resistance in 2BW, but the least wear resistance in 3BW against zirconia. Regarding 2BW, a direct/indirect composite material pair of the same manufacturer showed the significantly highest mean volume losses (2.72/2.85 mm³), followed by LS₂ (1.41 mm³). LS₂ presented the best wear resistance in 3BW (mean wear depth 2.85 µm), combined with the highest mean Vickers hardness (598 MPa). No linear correlation was found between Vickers hardness and both wear testing procedures. The zirconia antagonists showed no recordable signs of wear.

SIGNIFICANCE

Dental restorative materials behave differently in 2BW and 3BW laboratory testing. Vickers hardness testing alone cannot hold for a correlation with wear behavior of materials. Micromorphological investigation of material composition can reveal insights in wear mechanisms related to variations in filler technologies.