Objective:
To evaluate the clinical behavior of all-ceramic inlay-retained bridges (IRB) after an average observation period of 18 months.
Method:
20 all-ceramic 3-unit IRBs (IPS e.max ZirCAD/ZirPress, Ivoclar Vivadent, Schaan, FL) were adhesively cemented (total etch technique) and evaluated clinically after an average observation period of 18 months by means of FDI criteria for evaluation of indirect restorations (Hickel et al. 2007). These criteria include the evaluation concerning esthetic (A), functional (B) and biological (C) properties. In addition a SQUACE evaluation (semi quantitative clinical evaluation) of each restoration was conducted. For statistical analysis SPSS 16.00 was used.
Results:
After a mean observation time of 18 months all IRBs were in function.
properties | % of restorations | ||||||
A = esthetic | B = functional | C = biological | |||||
surface luster | marginal staining | color stability / translucency | fractures / retention | marginal adaptation / marginal irregularity | patient's view | postoperative (hyper-) sensitivity | |
α1 excellent / very good | 20 | 65 | 85 | 75 | 40 | 80 | 95 |
α2 good, after correction very good | 75 | 35 | 15 | 10 | 50 | 15 | 5 |
β sufficient, no unacceptable effects | 5 | --- | --- | 10 | 10 | 5 | --- |
γ unsatisfactory, but reparable | --- | --- | --- | 5 | --- | --- | --- |
The SQUACE evaluation revealed mean values for marginal staining of 1.75%(±2.45) and marginal irregularities for 7.25%(±7.52) of the IRB`s total margin length.
Conclusion:
After an average time of 18 months clinical service 95% of the 3-unit all-ceramic IRBs presented an excellent to sufficient clinical behavior. Only in one case the veneering material fractured (including the margin), but it was reparable and the IRB is still in function. For marginal adaptation 2 cases were rated as beta, but overall only 7.25% marginal irregularities of IRB`s total margin occurred.
Therefore, all-ceramic IRBs made of IPS e.max ZirCAD/ZirPress seem reliable as a defect-oriented alternative for posterior single tooth replacement.