IADR Abstract Archives
In Vitro Characterization of Additively and Subtractively Manufactured Zirconia Restorations
Objectives: The subtractive manufacturing process of zirconia restorations is material-consuming, requires manual surface post-processing and limits the aesthetic potential of the restorations. To overcome these shortcomings, an additive manufacturing process resulting in self-glazed zirconia restorations (Y-TZPSG) was developed. This in vitro investigation aimed at characterizing three-unit fixed dental prostheses (FDPs) fabricated using this novel process in terms of elemental composition, surface topography as well as fracture strength and to compare them to subtractively manufactured and glazed controls (Y-TZPC).
Methods: FDPs were fabricated either additively (n=16) or subtractively (n=16). Half of the samples of each group (n=8) was subjected to 5 million cycles of thermocyclic loading in an aqueous environment in a chewing simulator with a vertical load of 98 N. The elemental composition of the FDPs was analyzed by energy dispersive X-ray spectroscopy. Surface topography was characterized by scanning electron and laserscanning microscopy and fracture stability was evaluated by loading the FDPs in a universal testing machine until fracture occurred. Normally distributed data was analyzed for statistically significant differences using a one-way ANOVA followed by a Tukey`s HSD test whereas a Kruskal Wallis ANOVA followed by a Dunn`s test was applied for not normally distributed data.
Results: Y-TZPSG demonstrated a comparable elemental composition to the control group but showed higher average surface roughness. Fracture stability of Y-TZPSG was significantly higher than that of Y-TZPC. Y-TZPSG displayed a decrease from 5164 N to 4507 N after aging whereas the fracture stability of Y-TZPC (before chewing simulation: 1923 N, after: 2041 N) was not affected statistically significant by aging.
Conclusions: Within the limits of this investigation, it can be concluded that Y-TZPSG appears to be stable for the clinical application and seems to be a promising candidate for the fabrication of all-ceramic dental restorations. However, clinical investigations have to prove clinical applicability.
Methods: FDPs were fabricated either additively (n=16) or subtractively (n=16). Half of the samples of each group (n=8) was subjected to 5 million cycles of thermocyclic loading in an aqueous environment in a chewing simulator with a vertical load of 98 N. The elemental composition of the FDPs was analyzed by energy dispersive X-ray spectroscopy. Surface topography was characterized by scanning electron and laserscanning microscopy and fracture stability was evaluated by loading the FDPs in a universal testing machine until fracture occurred. Normally distributed data was analyzed for statistically significant differences using a one-way ANOVA followed by a Tukey`s HSD test whereas a Kruskal Wallis ANOVA followed by a Dunn`s test was applied for not normally distributed data.
Results: Y-TZPSG demonstrated a comparable elemental composition to the control group but showed higher average surface roughness. Fracture stability of Y-TZPSG was significantly higher than that of Y-TZPC. Y-TZPSG displayed a decrease from 5164 N to 4507 N after aging whereas the fracture stability of Y-TZPC (before chewing simulation: 1923 N, after: 2041 N) was not affected statistically significant by aging.
Conclusions: Within the limits of this investigation, it can be concluded that Y-TZPSG appears to be stable for the clinical application and seems to be a promising candidate for the fabrication of all-ceramic dental restorations. However, clinical investigations have to prove clinical applicability.