- 學位論文
金屬表面處理對鈦/牙科陶瓷鍵結強度之影響
Effect of metallic surface treatments on the bond strength of titanium-dental ceramic
摘要
在牙醫學中，陶瓷融合金屬冠是固定式補綴物中常見的牙科修復物。鈦金屬擁有多項優點，如優異的生物相容性、抗腐蝕性佳、高比強度、機械性質良好及低密度等優點。可是鈦作為陶瓷融合金屬冠的金屬基材時，存在著鈦與牙科陶瓷間結合性的問題。本研究選用商業用二級純鈦為基材，利用浸泡處理及熱處理兩種表面處理方式，除經由三點彎曲試驗評估鈦/陶瓷間鍵結強度外，並使用XRD分析試片表面結構，利用SEM觀察表面形態，藉由GDS推估鈦氧化層厚度。另於冷熱循環試驗後同樣藉由三點彎曲試驗測試鍵結強度。所有鍵結強度值的統計分析運用單因子變異數分析及涂凱氏事後比較。 實驗結果顯示，使用熱處理的方式會使鈦表面形成厚度小於4 μm的rutile相的TiO2氧化層，特別當熱處理溫度於700℃至800℃間，可增加鈦與陶瓷的鍵結強度且與控制組相比具有統計學上的差異(p<0.05)。然而當熱處理溫度高達850℃時，則強度值與最佳結果相比較，明顯減少約30%。單就只經浸泡處理的組別，其強度值無異於控制組，無統計上的差異。破壞面形態結果分析，經熱處理後的破壞路徑為沿著界面反應層/陶瓷層間，以及在界面反應層區域範圍內的混合型破壞模式。冷熱循環試驗不會對鈦/牙科陶瓷間的鍵結強度造成影響。
並列摘要
The porcelain fused to metal restorations is generally used in fixed prosthetic dentistry. Titanium is well known for its advantages, such as excellent biocompatibility, corrosion resistance, high strength-to-weight ratio, appropriate mechanical properties, and lower density. However, there are still remaining problems with firing ceramic on titanium. In the study, titanium was subjected to different immersed treatments and preheating temperatures. The treated surfaces were analyzed by using XRD, SEM and GDS. The bond strength of titanium-dental ceramic with and without thermal cycling test was measured by the three-point bending test. The results were statistically analyzed using one-way ANOVA and Tukey test. The results showed that heat-treated samples consisted of rutile phase of titania (TiO2) and had a thickness less than 4 μm. The Ti-ceramic bond strength values of heat treatment at 700 ~ 800 oC in this study was statistically significantly higher than those in control group (p<0.05). However, higher temperature of 850 oC adversely affected the bonding strength with a reduction of 30 % of the highest value. Immersed treatment alone provided no beneficial effect to the Ti-ceramic system in term of bond strength compared to control group, presenting no statistically significant difference. It was found that the fracture paths of Ti-ceramic after heat treatment mainly occurred at the interface and within the interaction zone of TiO2 layer. Thermal cycling testing did not affect the strength of Ti-ceramic sample.