• The Journal of Advanced Prosthodontics
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• v.4 no.2
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• pp.76-83
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• 2012

PURPOSE. Zirconia has been used in clinical dentistry for approximately a decade, and there have been several reports regarding the clinical performance and survival rates of zirconia-based restorations. The aim of this article was to review the literatures published from 2000 to 2010 regarding the clinical performance and the causes of failure of zirconia fixed partial dentures (FPDs). MATERIALS AND METHODS. An electronic search of English peer-reviewed dental literatures was performed through PubMed to obtain all the clinical studies focused on the performance of the zirconia FPDs. The electronic search was supplemented by manual searching through the references of the selected articles for possible inclusion of some articles. Randomized controlled clinical trials, longitudinal prospective and retrospective cohort studies were the focuses of this review. Articles that did not focus on the restoration of teeth using zirconia-based restorations were excluded from this review. RESULTS. There have been three studies for the study of zirconia single crowns. The clinical outcome was satisfactory (acceptable) according to the CDA evaluation. There have been 14 studies for the study of zirconia FPDs. The survival rates of zirconia anterior and posterior FPDs ranged between 73.9% - 100% after 2 - 5 years. The causes of failure were veneer fracture, ceramic core fracture, abutment tooth fracture, secondary caries, and restoration dislodgment. CONCLUSION. The overall performance of zirconia FPDs was satisfactory according to either USPHS criteria or CDA evaluations. Fracture resistance of core and veneering ceramics, bonding between core and veneering materials, and marginal discrepancy of zirconia-based restorations were discussed as the causes of failure. Because of its repeated occurrence in many studies, future researches are essentially required to clarify this problem and to reduce the fracture incident.

• The Journal of Advanced Prosthodontics
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• v.3 no.4
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• pp.221-228
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• 2011

PURPOSE. Veneering porcelain might be delaminated from underlying zirconia-based ceramics. The aim of this study was the evaluation of the effect of different surface treatments and type of zirconia (white or colored) on shear bond strength (SBS) of zirconia core and its veneering porcelain. MATERIALS AND METHODS. Eighty zirconia disks (40 white and 40 colored; 10 mm in diameter and 4 mm thick) were treated with three different mechanical surface conditioning methods (Sandblasting with $110{\mu}m$ $Al_2O_3$ particle, grinding, sandblasting and liner application). One group had received no treatment. These disks were veneered with 3 mm thick and 5 mm diameter Cercon Ceram Kiss porcelain and SBS test was conducted (cross-head speed = 1 mm/min). Two and one way ANOVA, Tukey's HSD Past hoc, and T- test were selected to analyzed the data (${\alpha}=0.05$). RESULTS. In this study, the factor of different types of zirconia ceramics (P=.462) had no significant effect on SBS, but the factors of different surface modification techniques (P=.005) and interaction effect (P=.018) had a significant effect on SBS. Within colored zirconia group, there were no significant differences in mean SBS among the four surface treatment subgroups (P=0.183). Within white zirconia group, "Ground group" exhibited a significantly lower SBS value than "as milled" or control (P=0.001) and liner (P=.05) groups. CONCLUSION. Type of zirconia did not have any effect on bond strength between zirconia core and veneer ceramic. Surface treatment had different effects on the SBS of the different zirconia types and grinding dramatically decreased the SBS of white zirconia- porcelain.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.7
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• pp.783-788
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• 2011

The recent development of bio-ceramic material is being studied in various bio-material engineering field. There are lots of technical difficulties because manufacturing or bonding technique are required bio-friendliness, cleanliness and persistence. Zirconia ceramic powder is cladded on Ti-6AI-4V metallurgically by laser cladding processing. Laser cladding system with powder feeding delivery is designed and manufactured for optimum processing condition. Increasing of manufacturing speed and good quality of clad layer are achieved by application of preheating of substrate before laser cladding. The thin dilution and good clad layer on the substrate are obtained for applications of bio-materials such as the dental materials and the articulated joints of human body.

• Journal of the Korean Ceramic Society
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• v.43 no.9 s.292
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• pp.515-518
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• 2006

The microstructure of $ZrO_2$ toughened $Al_2O_3$ ceramics was carefully controlled so as to obtain dense and fine-grained ceramics, thereby improving the properties and reliability of the ceramics for capillary applications in semiconductor bonding technology. $Al_2O_3-ZrO_2(Y_2O_3)$ composite was produced via Ceramic Injection Molding (CIM) technology, followed by Sinter-HIP process. Room temperature strength, hardness, Young's modulus, thermal expansion coefficient and toughness were determined, as well as surface strengthening induced by the fine grained homogenous microstructure and the thermal treatment. The changes in alumina/zirconia grain size, sintering condition and HIP treatment were found to be correlated.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.201-201
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• 2005

• The korean journal of orthodontics
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• v.45 no.4
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• pp.164-170
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• 2015

Objective: The aim of this study was to compare the shear bond strength (SBS) of orthodontic brackets bonded to zirconia surfaces using three different zirconia primers and one silane primer, and subjected to thermocycling. Methods: We designed 10 experimental groups following the surface treatment and thermocycling. The surface was treated with one of the following method: no-primer (NP), Porcelain Conditioner (PC), Z-PRIME Plus (ZP), Monobond Plus (MP) and Zirconia Liner Premium (ZL) (n=20). Then each group was subdivided to non-thermocycled and thermocycled groups (NPT, PC, ZPT, MPT, ZLT) (n=10). Orthodontic brackets were bonded to the specimens using $Transbond^{TM}$ XT Paste and light cured for 15 s at $1,100mW/cm^2$. The SBS was measured at a 1 mm/min crosshead speed. The failure mode was assessed by examination with a stereomicroscope and the amount of bonding resin remaining on the zirconia surface was scored using the modified adhesive remnant index (ARI). Results: The SBS of all experimental groups decreased after thermocycling. Before thermocycling, the SBS was ZL, $ZP{\geq}MP{\geq}PC>NP$ but after thermocycling, the SBS was $ZLT{\geq}MPT{\geq}ZPT>PCT=NPT$ (p > 0.05). For the ARI score, both of the groups lacking primer (NP and NPT) displayed adhesive failure modes, but the groups with zirconia primers (ZP, ZPT, MP, MPT, ZL, and ZLT) were associated with mixed failure modes. Conclusions: Surface treatment with a zirconia primer increases the SBS relative to no-primer or silane primer application between orthodontic brackets and zirconia prostheses.

• The korean journal of orthodontics
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• v.53 no.3
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• pp.139-149
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• 2023

Objective: To assess the color stability and translucency of full cubic stabilized zirconia (FSZ) following orthodontic bonding with different surface treatments and coffee thermocycling (CTC). Methods: This in vitro study was conducted on 120 disc-shaped specimens of FSZ. Thirty specimens were selected as the control group and remained intact. The remaining specimens were randomly divided into three groups based on the type of surface treatment (n = 30): airborne particle abrasion (APA), silica-coating (CoJet), and carbon dioxide (CO₂) laser. After metal bracket bonding in the test groups, debonding and polishing were performed. Subsequently, all specimens underwent CTC (10,000 cycles). Color parameters, color difference (ΔE₀₀), and translucency parameter (TP) were measured three times at baseline (t0), after debonding and polishing (t1), and after CTC (t2). Data were statistically analyzed (α = 0.05). Results: Significant difference existed among the groups regarding ΔE₀₀t0t2 (p < 0.001). The APA group showed minimum (ΔE₀₀ = 1.15 ± 0.53) and the control group showed maximum (ΔE₀₀ = 0.19 ± 0.02) color stability, with no significant difference between the laser and CoJet groups (p = 0.511). The four groups were significantly different regarding ΔTPt0t2 (p < 0.001). Maximal increases in TP were noted in the CoJet (1.00 ± 0.18) and APA (1.04 ± 0.38) groups while minimal increase was recorded in the control group (0.1 ± 0.02). Conclusions: Orthodontic treatment makes zirconia restorations susceptible to discoloration and increased translucency. Nonetheless, the recorded ΔE₀₀ and ΔTP did not exceed the acceptability threshold.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.6
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• pp.743-752
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• 2007

Statement of problem. The aims of the study were to evaluate the effect of current surface conditioning methods on the bond strength of a resin composite luting cement bonded to ceramic surfaces and to identify the optimum cement type. Material and methods. The sixty zirconia ceramic specimens(10 per group) with EVEREST milling machine and 60 tooth block were made. The zirconia ceramic surface was divided into two groups according to surface treatment: (1) airborne abrasion with $110{\mu}m$ aluminum oxide particles; (2) Rocatec system, tribochemical silica coating. The zirconia ceramic specimens were cemented to tooth block using resin cements. The tested resin cements were Rely X ARC, Panavia F and Superbond C&B. Each specimen was mount in a jig of the universal testing machine for shear strength. The results were subjected to 2-way ANOVA and Post hoc tests was performed using Tukey, Scheffe, and Bonferroni test. Results. The mean value of shear bond strength(MPa) were as follows: $$RelyXARC(+Al_2O_3),5.35{\pm}1.69$$; $$RelyXARC(+Rocatec),8.50{\pm}2.13$$; $$PanaviaF(+Al_2O_3),9.58{\pm}1.13$$; $$PanaviaF(+Rocatec),12.98{\pm}1.71$$; $$SuperbondC&B(+Al_2O_3)8.27{\pm}2.04$$; $$SuperbondC&B(+Rocatec),14.46{\pm}2.39$$. There was a significant increase in the shear bond strength when the ceramic surface was subjected to the tribochemical treatment(Rocatec 3M) in all cement groups(P<0.05). Bonding strengths of cements applied to samples treated with $Al_2O_3$ were compared; Rely X ARC showed the lowest values, whereas Panavia F cement showed higher value than that of Superbond C&B group with no statistical significance. When the bond strength of cements with of Rocatec treatment was compared, Rely X ARC showed lowest values. Overall, it was apparent that tribochemical treated Super-Bond possessed higher mean bond strength (14.46MPa; P<0.05) than that of Panavia F cement group with no significance. Conclusions. Silica coating followed silanization(Rocatec treatment) increase the bond strength between resin cement and zirconia ceramic. Panavia F containing phosphate monomer and Superbond C&B comprised of 4-META tend to bond chemically with zirconia ceramic, thus demonstrating higher bond strength compared to BisGMA resin cement. Superbond C&B has shown to have highest value of bonding strength to zirconia ceramic after Rocatec treatment compared to other cement.

• Journal of the Korean Ceramic Society
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• v.28 no.8
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• pp.654-660
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• 1991

Stabilized Zirconia (3 mol % Yttria, 3Y-TZP) was joined with intermetallic compound NiTi which has similar thermal expansion coefficient. The optimum bonding condition was determined by the Taguchi Method. Under the optimum bonding condition, the 4-point bending strength was as high as 400 MPa. bonding interfaces were examined by optical microscope, SEM, and TEM; reaction products were identified by XRD and TEM, The relationship between products and strength was examined.

• Journal of Technologic Dentistry
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• v.37 no.3
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• pp.121-127
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• 2015

Purpose: This study was intended to investigate the effect of applying liner for chemical bonding and physical surface roughness created on zirconia by using a sandpaper before sintering on the bond strength between the two materials. Methods: Zirconia blocks were cut using a low-speed cutter. Plate-shaped specimen($6mm{\times}6mm{\times}3mm$) was fabricated by sintering after giving surface roughness according to four kinds of sandpapers. Depending on whether or not to use liner, 60 specimens were divided into two groups ZN(non-liner), ZL(liner), and the two groups were subdivided into four groups respectively in accordance with sandpaper used, totaling eight groups (n=10). The surface roughness (Ra) values and shapes before sintering were observed, and shear bond strength after pressing ceramic plasticity was measured with a universal testing machine. For a test of the significance, a one-way ANOVA was performed, and Tukey's multiple comparison test was conducted. Results: The observation of the surface roughness was SB04($2.22{\pm}1.16{\mu}m$), SB08($2.98{\pm}0.33{\mu}m$), SB12($2.44{\pm}1.32{\mu}m$), SB20($2.34{\pm}0.59{\mu}m$) and SA04($2.34{\pm}0.67{\mu}m$), SA08($1.28{\pm}0.90{\mu}m$), SA12($2.03{\pm}1.60{\mu}m$), SA20($2.19{\pm}1.73{\mu}m$). In the case of ZN Group, the shear bond strength was ZN04($23.26{\pm}3.83MPa$), ZN08($21.76{\pm}2.33MPa$), ZN12($20.49{\pm}3.01MPa$), ZN20($24.98{\pm}4.22MPa$)(p<0.05). As for ZL Group, the shear bond strength was ZL04($25.09{\pm}5.67MPa$), ZL08($22.98{\pm}2.26MPa$), ZL12($21.54{\pm}5.70MPa$), ZL20($23.98{\pm}3.23MPa$)(p<0.05). Conclusion: The research results showed that the bond strength of Zirconia core and Pressing ceramic was further improved by physical surface treatment before sintering, rather than by chemical bonding through liner surface treatment.