• 대한치과보철학회지
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• 제47권2호
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• pp.148-155
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• 2009

연구목적: 최근에는 금속도재관의 심미적 문제로 심미성과 강도가 개선된 코아용 도재 및 지르코니아를 이용한 전부도재관 시스템에 관심이 증가되고 있다. 특히 금속과 유사한 강도를 가지면서 금속의 비심미성을 극복할 수 있는 지르코니아를 이용한 보철물의 제작이 국내외에서 많이 이뤄지고 있다. 하지만 CAD/CAM 시스템으로 제작되는 여러 종류의 지르코니아를 이용한 전부도재관의 적합도에 대한 임상 연구는 부족한 실정이다. 다양한 CAD/CAM 시스템 중 Procera, Cerec inLab, Lava에 의해 제작된 지르코니아를 이용한 전부도재관의 변연 적합도와 내면 적합도를 측정하여 이를 전통적인 방식으로 주조된 금속 도재관의 적합도와 비교 평가해 봄으로써 임상 적용에 참고 자료로 활용하고자 한다. 연구 재료 및 방법: 본 연구를 위해 하악 우측 제2소구치에 해당하는 레진치를 삭제하여 인상채득 후, 금속 주모형을 제작하였다. 금속 주모형의 40개의 인상을 채득 후 각 시스템마다 10개씩 총 40개의 crown을 제작하였다. 금속도재관은 전통적인 방식으로 제작하였고 Procera, Lava, Cerec inLab crown은 zirconia core를 이용하여 CAD/CAM 시스템으로 제작하였다. 수직 변연 오차와 내면 간격을 각 그룹마다 금속 주모형에 시멘트 접착 없이 측정하였다. 그 결과는 oneway ANOVA와 Tukey's HSD test로 통계 내었다. 결과: 수직 변연 오차는 금속도재관이 $50.6{\pm}13.9{\mu}m$, Procera crown이 $62.3{\pm}15.7{\mu}m$, Lava crown이 $45.3{\pm}7.9{\mu}m$, Cerec inLab crown은 $71.2{\pm}2.0{\mu}m$로 측정되었다. 내면 간격은 금속도재관이 $52.6{\pm}10.1{\mu}m$, Procera crown이$161.7{\pm}18.5{\mu}m$, Lava crown이 $63.0{\pm}10.2{\mu}m$, Cerec inLab crown이 $73.7{\pm}10.7{\mu}m$로 측정되었다. 변연 적합도 측면에서 볼 때 Procera crown, Lava crown, Cerec inLab 그리고 전통적인 금속도재관은 임상적으로 받아들일 수 있는 적합도 범위($120{\mu}m$) 내에 있었다. 내면 적합도 측면에서 볼 때 Procera crown을 제외한 Lava crown, Cerec inLab, 금속도재관은 임상적으로 받아들일 수 있는 적합도 범위($140{\mu}m$) 내에 있었다.

• 대한치과보철학회지
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• 제46권3호
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• pp.269-279
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• 2008

STATEMENT OF PROBLEM: Recently, various all-ceramic crowns fabricated with CAD/CAM systems have come into wide use in dental clinic. However, there are only few domestic studies on CAD/CAM restorations. PURPOSE: Purpose of this study was to compare the fidelity (absolute marginal discrepancy and internal gap) between various cores fabricated with different CAD/CAM systems (Procera system, Lava system, Cerec inLab system) and conventional metal cast core. MATERIALS AND METHODS: 10 cores per each system were fabricated. The absolute marginal discrepancies were measured using measuring microscope and digital counter. The internal gaps were calculated using a silicone paste. The results were statistically analyzed using the one-way ANOVA test and Tukey's HSD test. RESULTS: Within the limits of this study the results were as follows. 1. The absolute marginal discrepancies were $32.5{\pm}3.7\;{\mu}m$ for metal cast core, $72.2{\pm}7.0\;{\mu}m$ for Procera core, $40.8{\pm}5.4\;{\mu}m$ for Lava core, and $55.3{\pm}8.7\;{\mu}m$ for Cerec inLab core. The internal gaps were $38.4{\pm}5.7\;{\mu}m$ for metal cast core, $71.4{\pm}5.3\;{\mu}m$ for Procera core, $45.9{\pm}7.3\;{\mu}m$ for Lava core, and $51.8{\pm}6.2\;{\mu}m$ for Cerec inLab core. 2. The fidelity of metal cast core showed the smallest gaps, followed by Lava core, Cerec inLab core, and Procera core. CONCLUSION: The fidelities of 4 core groups were all within the clinically acceptable range ($120\;{\mu}m$).

• The Journal of Advanced Prosthodontics
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• 제12권3호
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• pp.131-139
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• 2020

PURPOSE. The purpose of this study is to evaluate the repair bond strength of a nanohybrid resin composite to three CAD/CAM blocks using different intraoral ceramic repair systems. MATERIALS AND METHODS. Three CAD/CAM blocks (Lava Ultimate, Cerasmart, and Vitablocks Mark II) were selected for the study. Thirty-two specimens were fabricated from each block. Specimens were randomly divided into eight groups for the following different intraoral repair systems: Group 1: control group (no treatment); Group 2: 34.5% phosphoric acid etching; Group 3: CoJet System; Group 4: Z-Prime Plus System; Group 5: GC Repair System; Group 6: Cimara System; Group 7: Porcelain Repair System; and Group 8: Clearfil Repair System. Then, nanohybrid resin composite (Tetric Evo Ceram) was packed onto treated blocks surfaces. The specimens were thermocycled before application of repair systems and after application of composite resin. After second thermal cycling, blocks were cut into bars (1 × 1 × 12 ㎣) for microtensile bond strength tests. Data were analyzed using two-way ANOVA and Tukey's HSD test (α=.05). RESULTS. Cimara System, Porcelain Repair, and Clearfil Repair systems significantly increased the bond strength of nanohybrid resin composite to all CAD/CAM blocks when compared with the other tested repair systems (P<.05). In terms of CAD/CAM blocks, the lowest values were observed in Vitablocks Mark II groups (P<.05). CONCLUSION. All repair systems used in the study exhibited clinically acceptable bond strength and can be recommended for clinical use.

• 대한치과기공학회지
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• 제31권2호
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• pp.23-30
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• 2009

All-ceramic restorations have gained acceptance among clinicians and patients because of their superior esthetics. Most all-ceramic systems have a 2-layer structure, using a weak veneering ceramic over a strong supporting core. often, failure of all-ceramic restorations occurs when the veneering ceramic fractures, exposing the core material. The purpose of this study was to compare the shear bond strength of heat press ceramic system (Zirpress) to zirconia core with various surface treatments. 10 metal cores and 50 zirconia cores were fabricated and divided into six groups according to surface treatment such as Zirliner application, aluminium oxide blasting, and 9.5% HF etching. Sixty specimens were prepared using Zirpress, veneered 8mm height and 3mm in diameter, over the zirconia cores (n=10). The shear bond strength test was performed in a universal testing machine with a crosshead speed of 1/min. Ultimate shear bond strength data were analyzed with One-way ANOVA and the Scheffe's test (p=.05). Within the limits of this study, the following conclusions were drawn: The mean shear bond strengths (MPa) were: 12.93 for $110{\mu}m$ aluminium oxide blasting/Rexillium III/IPS e.Max Zirpress; 14.92 for $50{\mu}m$ aluminium oxide blasting ${\pm}9.5%$ HF etching/Zirconis core/IPS e.Max Zirpress; 16.37 for $110{\mu}$ aluminium oxide blasting + 9.5% HF etching/Zirconis core/IPS e.Max Zirpress; 12.89 for $200{\mu}$ aluminium oxide blasting + 9.5% HF etching/Zirconis core/IPS e.Max Zirpress; 19.30 for 9.5% HF etching/Zirconis core/IPS e.Max Zirpress; 19.55 for Zirliner/Zirconis core/IPS e.Max Zirpress. The mean shear bond strength for ZNTZH (Zirliner/Zirconis core) and ZNTEH (9.5% HF etching/Zirconis core) were significantly superior to MS110H ($110{\mu}$ aluminium oxide blasting/Rexillium III) and ZS200EH ($200{\mu}$ aluminium oxide blasting + 9.5% HF etching/Zirconis core) (p<0.05).

• 대한치과보철학회지
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• 제38권6호
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• pp.806-813
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• 2000

Statement of problems. There are only a few studies available that deal with the clinical behavior of ceromer systems as potential substitutes for metal-ceramic crowns. Purpose. This prospective study was initiated to evaluate the clinical performance of 35 Sculpture crowns after 2 years in service. Material and methods. Thirty five Sculpture crowns were placed for 20 patients (7 men and 13 women). All patients were treated by the same dentist, and all restorations were fabricated by the same dental laboratory. Crown placement involved both the anterior and posterior regions of the dental arches. Patients were evaluated by two examiner at baseline, 12, and 24 months using the CDA quality assessment system in addition to periodontal criteria. Results. Of 34 crowns remaining in the study after 2 years, only one crown had experienced a marginal fracture. The crown was replaced as a result of recurrent caries. All remaining crowns were ranked as either excellent or acceptable for surface and color, anatomic form, and marginal integrity. Conclusion. The 2-year clinical observations and ranking with the CDA quality assessment criteria supported the conclusion that Sculpture crowns may be used in substitutes for metal-ceramic crowns.

• 한국전기전자재료학회논문지
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• 제24권12호
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• pp.969-976
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• 2011

In this study we aims to evaluate the effects of 1/3 mol% $Co_3O_4$ addition on the reaction, microstructure development, resultant electrical properties, and especially the bulk trap and grain boundary properties of $ZnO-Bi_2O_3-Sb_2O_3$ (Sb/Bi=2.0, 1.0, and 0.5) system (ZBS). The samples were prepared by conventional ceramic process, and characterized by XRD, density, SEM, I-V, impedance and modulus spectroscopy (IS & MS) measurement. In addition of $Co_3O_4$ in $ZnO-Bi_2O_3-Sb_2O_3$ (ZBSCo), the phase development, density, and microstructure were controlled by Sb/Bi ratio. Pyrochlore on cooling was reproduced in all systems. The more homogeneous microstructure was obtained in ZBSCo (Sb/Bi=1.0) system. In ZBSCo, the varistor characteristics were improved drastically (non-linear coefficient ${\alpha}$=23~50) compared to ZBS. Doping of $Co_3O_4$ to ZBS seemed to form $V^{\cdot}_o$(0.33 eV) as dominant defect. From IS & MS, especially the grain boundary of Sb/Bi=0.5 system is composed of electrically single barrier (0.93 eV) and somewhat sensitive to ambient oxygen with temperature.

• 대한치과보철학회지
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• 제43권4호
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• pp.466-477
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• 2005

Statement of problem : Problem of matching the appearance of porcelain restorations with the patient's natural dentition has always been a concern to dental clinicians. Recently, demands for esthetics, even in restorations requiring strength, has brought a revolution to dentistry and increased use of zirconia. Among the various factors, shade and translucency or the core can significantly affect the overall esthetics of the restoration and should be considered when selecting an all-ceramic system. Purpose : The purpose of this study was to spectrophotometrically evaluate the influence of different zirconia systems and core thickness on the final shade of all-ceramic restorations using the CIEL$^*a^*b^*$ system. Material and Methods: Core specimens (n : 20 per group) of In-Ceram Alumina, In-Ceram Zirconia, Digident CAD/CAM Zirconia, Cercon Zirconia were fabricated 20mm in diameter. 10 specimens of each group were fabricated at core thickness of 0.5mm and 0.7mm. These core specimens were veneered with shade Al & A3 porcelain of the recommended manufacturer. CIEL$^*a^*b^*$ coordinates were recorded for each specimen with a spectrophotometer (Model CM-2600d, Minolta, Japan). Color differences were calculated using the equation ${\Delta}E^*=[({\Delta}L^*)^2+({\Delta}a^*)^2+({\Delta}b^*)^2]^{\frac{1}{2}}$. Results : 1. Specimens of core thickness 0.5mm and 0.7mm did not exhibit clinically perceived color difference. 2. Regarding shade reproducibility, In-Ceram Alumina and In-Ceram Zirconia showed significant difference within each group. 3. Cercon Zirconia group showed the highest $L^*$ value and Digident Zirconia group showed lowest $a^*$ & $b^*$ value. 4. Generally the shade difference between materials was higher in the A3 shade group than in the Al shade group. Conclusion: Within the limitations of this study, there was no color difference after increase in core thickness and every all-ceramic system has color characteristics that clinicians have to consider when selecting materials. Also, manufacturers of different porcelain systems must make every effort to achieve color reproducibility.

• 대한치과보철학회지
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• 제41권3호
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• pp.379-386
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• 2003

Statement of problem. Resin cements are widely used in adhesive dentistry specially on all ceramic restorations. It is needed to find out adequate bonding strength between different porcelain surface treatments, commercially available porcelains, and different resin cement systems. Purpose. The purpose of this study was to evaluate shear bond strength of resin cements bonded to porcelains in three different modalities; 5 different porcelain surface treatments, 3 different resin cement systems and 3 different commercially available pressable porcelains. Material and Method. This study consisted of 3 parts. Part I examined the effect of five different surface treatments on the pressable porcelain. Fifty discs (5 mm in diameter and 3 mm in height) of Authentic porcelain were randomly divided into 5 groups (n = 10). The specimens were sanded with 320 grit SiC paper followed by 600 grit SiC paper. The specimens were treated as follow: Group 1-Sandblasting (aluminum oxide) only, Group 2 - sandblasting/ silane, Group 3 - sandblasting/ acid etching/ silane, Group 4 - acid etching only, Group 5 - acid etching/ silane. Part II examined the shear bond strength of 3 different resin cement systems (Duolink, Variolink II, Rely X ARC) on acid etching/ silane treated Authentic pressable porcelain. Part 3 examined the shear bond strength of Duolink resin cement on 3 different pressable porcelains (Authentic, Empress I, Finesse). All cemented specimens were stored in distilled water for 2 hours and tested with Ultradent shear bond strength test jig under Universal Instron machine until fracture. An analysis of variance(ANOVA) test was used to evaluate differences in shear bond strength. Result. The shear bond strength test resulted in the following: (1) Acid etched porcelains recorded greater shear bond strength values to the sandblasted porcelains. (2) Silane treated porcelains recorded greater shear bond strength values to non-silane treated porcelains. (3) There was no significant difference between sandblasting/ acid etching/ silane treated and acid etching/ silane treated porcelains. However those values were much higher than other three groups. (4) The shear bond strength with Variolink II was lower than the value of Duolink or Rely X ARC. (5) The shear bond strength of Finesse was lower than the value of Authentic or Empress I.

• The Journal of Advanced Prosthodontics
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• 제8권2호
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• pp.158-166
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• 2016

PURPOSE. The aim of this study was to determine the fracture resistance and the mode of fracture of endodontically treated teeth restored with different fiber posts and all-ceramic crowns. MATERIALS AND METHODS. Two glass fiber reinforced post systems in two different sizes and polyethylene fiber ribbon in two different thicknesses (n=10) were used. The specimens, restored with all-ceramic crowns, were subjected to a compressive load (in N) delivered at a 130-degree angle to the long axis until a fracture could be noted. The results were analyzed statistically with a One-Way ANOVA test (P<.05). RESULTS. Statistically significant differences were observed between the mean fracture resistance values of Postec, Snowlight, and Kerr Connect thin specimens (P<.0095). The Postec results (395.70 N) were found to be significantly higher than the others. No statistical difference was observed among the thick specimens (P<.2657). The mean fracture resistance values of the Snowlight thick samples were found to be higher than those of the Snowlight thin samples. The specimens were always fractured around the cemento-enamel junction at the palatinal side. No post fracture was observed for the thin Snowlight and Kerr Connect specimens or for the thick Postec and Kerr Connect specimens. Among the common failure types of the specimens, the worst was observed to be the root fracture failure. The highest post dislodgement failure result (80%) was obtained from the thin Kerr Connect specimen. CONCLUSION. In terms of optimizing fracture resistance, the fiber post size selection should be done according to the forces applied to the restored teeth.

• 구강회복응용과학지
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• 제31권3호
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• pp.231-241
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• 2015

환자의 심미적 요구가 증가함에 따라 전치뿐만 아니라 구치부에서도 자연치아와 유사한 색조와 외형을 재현한 보철물에 대한 필요성이 증가하고 있다. 단일 지르코니아와 CAD/CAM 시스템을 통해 이러한 환자의 요구를 만족시키는 보철물 제작이 가능해졌다. 본 증례는 70세 여자환자로 전치부 보철물이 깨져서 보기 싫고 하악 구치부가 없어서 저작이 불편하다는 주소로 내원하였다. 하악 구치의 상실로 교합평면이 붕괴되었으며 과도한 치아 마모 및 수직고경 상실이 관찰되어 치아 상실 부위에 임플란트를 식립하고 수직고경 증가와 함께 지르코니아 고정성 보철물을 이용한 전악 수복 치료를 진행하였다. 치료 후 3년 간 이상적인 교합이 잘 유지되고 기능적, 심미적으로 만족한 결과를 얻었기에 이를 보고하는 바이다.