- BruxZir is an excellent crown material; crowns look good, and so far I have had no failures after four years of regular use.
- Great implant crowns – they are opaque enough to mask the metal abutment but still look good.
- I love the way three- and four-unit bridges fit and look.
- No fractures at four years.
The purpose of this evaluation is to report on the clinical performance of BruxZir Solid Zirconia Crowns and Bridges at four years.
Clinical Evaluation Protocol
A total of 1,392 BruxZir Solid Zirconia Crowns and Bridges (Ecodent) restorations have been placed over the past 56 months. Nine hundred and thirteen (913) restorations were recalled over four months including: single crowns (84%), 7% of which were implant crowns, and 16% that were 3- and 4-unit bridges (Figure 1). Of the 913 recalled restorations, 5% were anterior crowns and 95% posterior crowns.
All restorations were cemented with adhesive and self-adhesive resin cements. Of the 913 recalled restorations, 18% were over 4 years old, 35% were between 3 and 4 years old and the remaining 47% were less than 3 years old.
The esthetics of BruxZir Solid Zirconia Crowns and Bridges was rated excellent, based on the consistency of the shades and a comparison of the esthetics to other monolithic zirconia restorations.
Resistance to Fracture/Chipping
Chipping and fracture of BruxZir Solid Zirconia Crowns and Bridges single crowns have been practically non-existent; three failures (0.3%) were observed. A second molar crown fractured, but failure was likely due to a lack of occlusal clearance and insufficient reduction. Having less than 1 mm of clearance is not recommended for molars. Two implant crowns on lower second molars fractured and one had to be replaced. The failure was again due to very low clearance and insufficient space due to implant placement. In one case, the abutment also failed. None of the three- or four-unit bridges fractured.
Resistance to Marginal Discoloration
Only five of the BruxZir Solid Zirconia Crowns and Bridges restorations (0.5%) exhibited slight marginal discoloration at four years . The opacity of the crowns helps camouflage most staining or microleakage. Also staining is a function of the bonding agent or cement rather than the zirconia.
Almost no wear was observed on BruxZir Solid Zirconia Crowns and Bridges restorations and very minimal wear was observed on opposing nautral dentition at four years. More wear was visible on gold crowns opposing BruxZir restorations.
Thirty-nine crowns (2.8%) out of the 1392 BruxZir Solid Zirconia Crowns and Bridges crowns debonded and required recementation (Figure 3). This debonding rate is slightly higher (2.8% vs 2.0%) when compared to non-zirconia crowns. Regular use of zirconia primers could result in a reduction of the debonding rate.
Over the four-year evaluation period, BruxZir Solid Zirconia Crowns and Bridges have proven to be excellent restorations with respect to esthetics and dependability. BruxZir Solid Zirconia Crowns and Bridges received a 98% clinical performance rating.