The comprehensive reports that follow evaluate the integrity and performance of BruxZir® Solid Zirconia. Biomaterials research, university studies and clinician reports were completed in order to examine how well a variety of materials embody the characteristics vital to high-quality dental restorations. Performance assessments, including long-term data, show that BruxZir restorations are excellent alternatives to PFMs and cast gold restorations. Furthermore, tests that evaluate strength, wear and translucency affirm the advantages of BruxZir Solid Zirconia compared to other all-ceramic restorations.
The clinical performance of BruxZir molar crowns was superior to all other tooth-colored materials studied previously by the TRAC research division of Clinicians Report® over the course of 39 years. Based on scanning electron microcoscope (SEM), clinical and laboratory examinations performed three-and-a-half years after placement, BruxZir crowns exhibited 23 percent less wear than the pressed ceramic-over-zirconia control group. Over the course of the study, BruxZir crowns received more wear than they caused, with no reports of microcracks, surface cratering or adverse occlusal system effects.
Specimens of the zirconia products were more translucent at 0.5 mm thickness than at 1.0 mm thickness. At the 0.5 mm thickness, the translucency parameter ranged from 10.3 to 10.7, and BruxZir was significantly more translucent than the other three products. At the 1.0 mm thickness, the translucency parameter ranged from 7.1 to 7.8, and BruxZir was significantly more translucent than Zenostar® Zr and Lava™ Plus. Translucency parameter was a function of wavelength when measured between 360-750 nm in reflection.
Conclusions: Ninety-eight percent of BruxZir Solid Zirconia Crown and Bridge restorations manufactured by Glidewell Dental Laboratories received a 5 or excellent rating at two-year recall. All of the single crowns and all of the three- and four-unit bridges had no evidence of fracture or chipping. One of two five-unit bridges failed shortly after cementation and was replaced. Over the two-year period, BruxZir has proven to be an excellent restoration with respect to esthetics, resistance to fracture/chipping, resistance to marginal discoloration, wear resistance, and retention. BruxZir received a clinical rating of 98%.
Although conventional belief might suggest that zirconia's high fracture strength and surface hardness would cause a greater degree of wear on enamel, a recent study found that the degree of wear on the opposing tooth was actually four times greater in dental porcelain than in polished, unglazed zirconia, suggesting that zirconia restorations are not only more fracture-resistant than porcelain restorations, but also gentler in their functional interaction with natural dentition.
BruxZir Solid Zirconia and Ceramco 3 were recently tested in a comparative wear study. Each material was tested using the Willytech Chewing Simulator, which simulated the clinical performance of the material over a period of five years. After 1.2 million wear cycles under a load of 5 kg, BruxZir compared favorably to Ceramco 3 with barely detectable wear.
Some dentists are concerned about the wear of enamel when opposing BruxZir full-contour zirconia crowns and bridges. In a recent study to measure the volumetric loss of enamel, glazed BruxZir was found to wear compatible with enamel and virtually identical to glazed IPS e.max.
BruxZir exhibits higher light transmission resulting in a more natural shade value.
SEM of sintered colloidally processed BruxZir vs. sintered isostatically pressed zirconia.
Lithium Disilicate ceramics have 400 MPa and typical zirconia materials have a flexural strength of more than 1200 MPa. However, because of post-powder processing, BruxZir Solid Zirconia dental restorations are able to exceed that strength threshold, with flexural strengths up to 1465 MPa.
The antagonistic (Steatite balls) wear shows BruxZir only with 72±21 micron, which is significantly lower than Ceramco 3, with 110±48 micron. The University of Tübingen study was run using an eight chamber Willytec Chewing Simulator at 1.2 million cycles.