Effects of dynamic aging on the wear and fracture strength of monolithic zirconia restorations

Abstract

BackgroundThe purpose of this study is to evaluate the wear and fracture strength of crowns and three-unit partial fixed dental prosthesis (FDP) fabricated using by Bruxzir and Incoris TZI as recently introduced monolithic zirconia materials.MethodsA total of sixteen crowns and sixteen three-unit FDPs were fabricated using Bruxzir and Incoris TZI (n = 8). All specimens were subjected to a 2-body wear test in a dual axis chewing simulator for 1,200,000 loading cycles against steatite antagonist balls. The fracture strength and volumetric loss were recorded. The obtained data were statistically analyzed by 2-way ANOVA testing (α = 0.05).ResultsThe mean volumetric loss of the crowns was higher than that of the three-unit FDPs (p < 0.05). Of the two monolithic systems, Incoris TZI exhibited more wear than Bruxzir. The fracture strengths of Bruxzir crowns and FDPs were found to be higher than those of the crowns and FDPs fabricated with Incoris TZI (p < 0.05).ConclusionIn in vitro test conditions, Bruxzir and Incoris TZI monolithic zirconia systems are fracture-resistant for the crown and FDP application against physiologic chewing forces owing to dynamic aging. Among newly developed monolithic zirconia materials, Bruxzir is found to be more resistant to fracture compared to the Incoris TZI.

Evaluation of wear and fracture strength of zirconia-based ceramics and metal-supported ceramics after treatment with the chewing simulator

“…Most of the studies evaluated flexural strength rather than fracture resintance [11,28,[30][31][32]. Similar to Stawarczyk et al [12], Flinn et al [28,30] Among the zirconia, as also observed in the present study, BruxZir was suggested to have superior physical properties and fracture resistance since it was indicated for patients with bruxism [29,35].…”

“…In contrast, in the present study, BruxZir and Prettau exhibited superior fracture resistance compared to Katana while occlusal wear area and volume were similar. Similarly, Sarikaya and Hayran, reported no fracture despite 5-year artificial aging in BruxZir and InCoris TZI zirconia material [29]. There was no fracture observed during the aging procedure in the present study either.…”

“…There was no fracture observed during the aging procedure in the present study either. A possible explanation for the difference might be the sample thickness which was 0.2 mm in Flinn et al [28]'s study while it was 1.5 mm in Sarikaya and Hayran [29]'s reports and the present study.…”

“…The possible reason for the difference might be the different aging procedure used. As for InCoris TZI, studies reported decreased mechanical features after aging; however, the change was found clinically insignificant [5,29]. In terms of present results, the highest wear area was located in PFM, and all zirconia had lower wear compared to PFM.…”

“…The present study used an artificial aging model with 240000 cycles of CS and 10000 cycles of TC which provide both thermal and mechanical stimulus. Various studies reported different aging models ranging from 5 hours to 1200000 cycles [11,22,26,29]. Steam autoclave aging was also used for artificial aging; [28,32] however, TC is more preferred to mimic oral conditions and provide LTD [11,26,29,39].…”