Dental Literature Watch · Trial · Prosthodontics
Five-Year Zirconia Bridges: Every Chip Was in a Veneered One
TL;DR
- Three-unit posterior bridges in 4 mol% yttria partially stabilised zirconia, randomised to monolithic, partially veneered, or fully veneered.
- Five-year survival: 94.7% monolithic, 100% partially veneered, 100% fully veneered.
- Technical complications occurred exclusively in the veneered groups — 33% partially veneered, 38% fully veneered, 0% monolithic (p ≤ 0.014).
- All complications were minor, polishable chipping, not catastrophic fracture.
- Periodontal parameters were stable and equivalent across all three designs.
- Veneered bridges scored better on professional colour rating, but patients reported no difference.
The study
| Design | Multicentre randomised controlled clinical trial, 5 years |
| Sample | 64 patients needing three-unit posterior FDPs; 63 evaluated at baseline, 57 at 3 years, 54 at 5 years |
| Material | All from 4Y-TZP; monolithic (MONO), partially veneered (PV), fully veneered (FV) |
| Survival at 5 years | 94.7% MONO, 100% PV, 100% FV |
| Technical complications | 0% MONO, 33% PV, 38% FV — all minor polishable chipping (p ≤ 0.014) |
| Biology | PPD, BOP, PI stable and equivalent across groups |
| Patient-reported | No difference between designs |
💎 Insight — what this means chairside
A clean split between two kinds of failure
The monolithic group had one survival event and no chipping; the veneered groups never lost a bridge but chipped in about a third of cases.
So the choice is between a small chance of losing the restoration and a substantial chance of a polishing appointment.
The monolithic group had one survival event and no chipping; the veneered groups never lost a bridge but chipped in about a third of cases.
So the choice is between a small chance of losing the restoration and a substantial chance of a polishing appointment.
The porcelain is the weak layer, again
Every technical complication in five years happened in veneering porcelain, none in the zirconia core.
This is the same lesson that drove the shift to monolithic restorations and it holds at five years in a randomised design.
Every technical complication in five years happened in veneering porcelain, none in the zirconia core.
This is the same lesson that drove the shift to monolithic restorations and it holds at five years in a randomised design.
Only the professionals cared about the colour
Veneered bridges got more favourable colour ratings from clinicians, while patient-reported outcomes were similar.
In a posterior three-unit bridge, that is an argument for monolithic that patients will not resent.
Veneered bridges got more favourable colour ratings from clinicians, while patient-reported outcomes were similar.
In a posterior three-unit bridge, that is an argument for monolithic that patients will not resent.
⚠️ The catch
Sixty-four patients, 54 at five years
With this sample, one survival event produces the entire 94.7% versus 100% difference.
The chipping difference is the statistically robust finding here; the survival difference is not.
With this sample, one survival event produces the entire 94.7% versus 100% difference.
The chipping difference is the statistically robust finding here; the survival difference is not.
Posterior three-unit only, in 4Y-TZP
Do not extend this to long-span bridges, anterior aesthetics, or the more translucent or more opaque zirconia generations.
Do not extend this to long-span bridges, anterior aesthetics, or the more translucent or more opaque zirconia generations.
⚡ Bottom line
- Three-unit posterior bridge → monolithic zirconia had zero chipping over five years.
- Patient wants the best-looking option → clinicians rated veneered better; patients could not tell.
- Choosing veneered anyway → counsel that about a third chipped, minor and polishable.
- Worried about the gingiva around monolithic zirconia → periodontal parameters were equivalent.
🧪 Questions
Tap an answer — instant grade, deciding line, and the trap.
You are planning a three-unit posterior bridge for a 58-year-old with a heavy bite. He asks which design lasts best. Based on the 2026 five-year multicentre trial, what is the most accurate summary?
Deciding line: survival was high across all three designs, while technical complications were confined to the partially and fully veneered groups at 33% and 38% versus 0% for monolithic. Trap: the last option is the engineered trap because the trial genuinely found equivalence on periodontal and patient-reported outcomes, which makes it easy to overlook the one outcome where the groups differed significantly.