| Due to the excellent aesthetic characteristics, good physical properties and stable chemical performance, all-ceramic restorations are increasingly widely used in clinic. However, the strength, fracture toughness, aesthetics, etc of all-ceramic restorations produced by different dental ceramic materials or with different production process are different[1]. To meet with complicated conditions, we need to make different types of tooth restorations. This prospective experiment investigats the clinical efficacy of three kinds of commonly used porcelain materials and discuss the effects of different ceramic materials and different types, different tooth region, veneering ceramics, use time and other factors on the clinical curative effect of the all-ceramic restoration, also analyse the failure reasons. The aim the this study is to provide suggestions and references on better design and production for clinical restoration, so as to improve the restoration survival time and survival rate.Objective.Our aim is to explore the clinical efficacy and failure reasons of the three common porcelain materials, to analyze all-ceramic materials, types, tooth regions, veneering ceramics, use time and other factors on the effect of survival rate of the all-ceramic restoration. We hope to provide clinical data for the selection of a suitable all-ceramic material, reasonable design and production of all-ceramic restorations.Materials and methods:Prospective study method is used to explore 282 IPS e.max Press casting porcelain restorations(140 patients), 401 pieces of Wieland zirconia restorations(298 patients) and 750 domestic zirconia restorations(580 patients) made in department of prosthodontics, our school of stomatology for 1-3 years clinical efficacy research, with reference to California Dental Association(CDA) standards. The Kaplan Meier survival analysis, the Log Rank test and Fisher exact test are used to analyze the impact of factors such as restoration materials, the types, teeth, veneering ceramics, service time on the survival rate of the all-ceramic restorations.Result:1. Chipping fractures were observed for 2 restorations, 2 restorations falled off, intense gingivitis for 1 restorations and periapical inflammation for 1 restorations during the observation period for IPS e.max Press restorations. The 3-year cumulative survival rate(CSR) of IPS e.max Press restorations was 97.9%. The differences among the CSR of single crowns(98.6%), veneers(96.9%) and linked crowns(94.1%)were not statistically significant(P= 0.430). The difference was not statistically significant(P= 0.408) between the CSR of the anterior region group(97.6%) and posterior region group(100%). The number of failed restorations in the first year accounted for 50% of the total number of failed restoration, the first three months of failed restorations accounted for 66.7% of the total failure in first year, but according to the failure rate of 95 % CI, it showed that 1, 2, 3-year restoration failure rates were not statistically significant.2. Chipping fractures were observed for 6 restorations, intense gingivitis for 4 restorations and periapical inflammation for 3 restorations during the observation period in Wieland zirconia restorations. The 3-year cumulative survival rate(CSR) of Wieland zirconia restorations was 96.8%, The differences among the CSR of single crowns(97.8%), linked crowns(92.2%)and fixed partial dentures(96.2%)were not statistically significant(P= 0.403). The difference was not statistically significant(P= 0.323) between the CSR of the anterior region group(95.5%) and posterior region group(97.4%). Fisher exact test showed that the difference of Wieland zirconia of failure rate and ceramic chipping fracture incidence were not statistically significant between veneering ceramics group and no veneering ceramics group. The number of failed restorations in first year accounted for 38.5% of the total number of failed restoration, and the number of failed restoration in the second year accounted for 53.8% of the total failure of the restoration, but the failure rate of 95 % CI show that 1, 2, 3-year restoration failure rates were not statistically significant.3. Chipping fractures were observed for 10 restorations, intense gingivitis for 1 restoration, periapical inflammation for 2 restorations and 3 restorations falled off during the observation period in domestic zirconia restorations. The differences among the CSR of single crowns(98.0%), linked crowns(97.6%)and fixed partial dentures(98.2%)were not statistically significant(P= 0.817). The difference was not statistically significant(P=0.311) between the CSR of the anterior region group(97.1%) and posterior region group(98.2%). Fisher exact test showed that ceramic chipping fracture incidence and failure rate of domestic zirconia were statistically significant between veneering ceramics group and without veneering ceramics group.The first three months of failed restorations 47.1% of the total failure in first year,but the failure rate of 95 % CI showed that 1, 2, 3-year restoration failure rates were not statistically significant.4. The 3-year cumulative survival rates(CSR) of IPS e.max Press restorations and Wieland zirconia restorations were 98.3% and 96.3% respectively. The 1-year CSR of domestic zirconia restorations was 97.7%. Log Rank test results show that the difference of 3-year CSR was not statistically significant between IPS e.max Press restorations and Wieland zirconia restorations(P >0.05). Log Rank test results show that the difference of 1-year CSR was not statistically significant between Wieland zirconia restorations and domestic zirconia restorations(P >0.05).Conclusion:1. The 3-year cumulative survival rate of IPS e.max Press restorations,Wieland zirconia and the 1-year CSR of domestic zirconia restorations are high. The short/medium clinical results of three all-ceramic materials are good.2. Porcelain fracture is the main reason for the failure of the all-ceramic restorations..3. Failure time of the IPS e.max Press and domestic zirconia restoration were mainly concentrated in the first year after the bonding. The restorations had a high failure rate in the first three months of the first year. Failure time of the Wieland zirconia was concentrated in 1-year or 2-year.4. In the present study, restoration types and tooth regions had no significant effect on survival of IPS e.max Press restorations. Restoration types, tooth regions and whether veneering or not had no significant effect on survival of Wieland zirconia restoration. Restoration types, tooth regions had no significant effect on survival of domestic zirconia restorations. But ceramic chipping fracture incidence and failure rate of different domestic zirconia were statistically significant between veneering ceramics group and no veneering ceramics group. |
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