• 한국정밀공학회지
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• 제23권10호
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• pp.74-79
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• 2006

In this study, the tempering effect on the wear characteristics of induction-hardened SPS5 steel was investigated. For this purpose, three tempering conditions were applied to control the hardness of heat-treated SPS5 steel. Ball-on-disk wear tests have been performed using zircornia balls on the tempered specimens to determine the variation of wear characteristics. The results showed that friction coefficient decreased with increasing hardness for induction hardening conditions. This seems to occur because real contact area between specimen and mating ball was affected by the specimen hardness.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.409-410
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• 2006

In this study, the tempering effect on the wear characteristics of induction-hardened SPS5 steel was investigated. For this purpose, three tempering conditions were applied to control the hardness of heat-treated SPS5 steel. Ball-on-disk wear tests have been performed using zircornia balls on the tempered specimens to determine the variation of wear characteristics. The results showed that friction coefficient decreased with increasing hardness for induction hardening conditions. This seems to occur because real contact area between specimen and mating ball was affected by the specimen hardness.

• The Journal of Advanced Prosthodontics
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• 제11권5호
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• pp.297-304
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• 2019

PURPOSE. This in vitro study investigated the repair bond strength of the zirconia ceramic after different aging conditions. MATERIALS AND METHODS. In order to imitate the failure modes of veneered zirconia restorations, veneer ceramic, zirconia, and veneer ceramic-zirconia specimens were prepared and were divided into 4 subgroups as: control ($37^{\circ}C$ distilled water for 24 hours ) and 3000, 6000, 12000 thermal cycling groups (n=15). Then, specimens were bonded to composite resin using a porcelain repair kit according to the manufacturer recommendation. The repair bond strength (RBS) test was performed using a universal testing machine (0.5 mm/min). Failure types were analyzed under a stereomicroscope. Two-way ANOVA and Bonferroni test were used for statistical analysis. RESULTS. The RBS values of zirconia specimens were statistically significant and higher than veneer ceramic and veneer ceramic-zirconia specimens in control, 3000 and 6000 thermal cycling groups (P<.05). When 12000 thermal cycles were applied, the highest value was found in zirconia specimens but there was no statistically significant difference between veneer ceramic and veneer ceramic-zirconia specimens (P>.05). Veneer ceramic specimens exhibited cohesive failure types, zirconia specimens exhibited adhesive failure types, and veneer ceramic-zirconia specimens exhibited predominately mixed failure types. CONCLUSION. Thermal cycling can adversely affect RBS of composite resin binded to level of fractured zirconia ceramics.

• 대한치과보철학회지
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• 제51권2호
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• pp.107-112
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• 2013

치관높이 공간이 과도할 경우 임플란트 몸체 혹은 구성물의 실패와 같은 고정성 보철물의 생역학적 합병증이 증가하며 치관 높이 공간이 12 mm 이상으로 과도한 경우는 고정성 보철물 선택에 유의하여야 한다. 고정성 보철물을 제작 시 치아들이 길어지므로 심미적 부위에서는 치은 색조를 띠는 재료를 사용해야 할 필요가 있다. 이러한 경우, 유지와 위생 관리가 적절하지 못하게 형성된 고정성 보철물은 음식물, 치태, 치석을 정체시키고 염증과 감염이 발생될 수 있으며 만성 염증과 감염으로 인해 외과적인 개선이 필요할 수 있다. 본 증례에서, 과도한 치관높이 공간을 가진 환자에게 발음 및 심미성을 고려하여 보철물 제작 후 보철물 주위의 치은 염증 및 부종이 발생하였으며, 그 원인이 구강위생을 어렵게 하는 보철물의 디자인으로 판단되어 치간공극을 충분히 형성한 임시 보철물을 장착 후 2개월 동안의 관찰 기간을 거치며 특이할 만한 이상 소견이 없음을 확인하였고 자가 위생 관리가 용이한 디자인으로 지르코니아 하부구조에 도재를 축성한 고정성 보철물로 구강회복을 시행하였으며, 일련의 치료과정을 통하여 부적절한 연조직 반응이 관찰 되지 않고 기능적인 면에서 만족스러운 결과를 얻을 수 있었다.