涂覆烧结金膏处理对三种钛瓷粉与纯钛结合强度的影响

Effect of sintering gold paste coating on the bonding strength of pure titanium and three low-fusing porcelains

目的探讨纯钛表面金膏涂覆烧结处理对3种钛瓷粉与纯钛结合强度的影响。方法根据ISO9693要求制备预成纯钛试件60个，以3种钛瓷粉（I：Initial Ti；S：Super porcelain Ti-22；T：TitanKeramik）进行分组，并根据烧结金膏涂层（G：Deckgold）与否进行亚组细分（GI、GS、GT、I、S、T组），每亚组10个钛一瓷标准试件。场发射扫描电镜观察钛-瓷结合界面的微观形貌。三点弯曲法测定钛-瓷结合强度，并进行统计学分析。体视显微镜观察各组钛-瓷断裂模式。结果场发射扫描电镜显示金膏涂层与钛、瓷结合紧密，内部偶见裂隙，以混合断裂为主；而未烧结金膏涂层组以界面断裂为主。GS和GI组结合强度分别为（37．08±4．32）和（36．20±2．40）MPa，相应高于S和I组[分别为（31．56±3．74）和（30．88±2．60）MPa]（P〈0．05），而GT与T组差异无统计学意义（P〉0．05）。结论在本项研究条件下，涂覆烧结金膏涂层可显著提高两种钛瓷粉与预成纯钛的结合强度。

Objective To study the effect of sintering gold paste coating of pure titanium on the adhesion of three porcelains following the protocol ISO 9693, and to investigate the titanium-porcelains interfaces. Methods Sixty machined pure titanium samples were prepared in a rectangular shape according to ISO 9693 and divided equally into six groups. Half of the strips were coated with gold paste （Deckgold） and sintered. Three ultra-low-fusing dental porcelains （I： Initial Ti, S： Super porcelain Ti-22, T： TitanKeramik） were fused onto the titanium surfaces. A thin layer of bonding agent was only applied on the surfaces of uncoated gold specimens. The interface of the porcelain and titanium was observed with a field emission scanning electron microscope （FE-SEM） after metallographic preparation and sputtered with a very thin carbon layer of the embedded titanium-porcelain interface. After three-point bending test was performed, optical stereomicroscope was used to characterize the titanium-porcelains adhesion and determine the mode of failure. Results FE-SEM illustrated intermetallie compounds of Au-Ti formed with some visible microcraeks in the gold layer and the interface of gold layer and ceramic. All the uncoated gold titanium-porcelain system showed predominately adhesive fracture at the titanium oxidation, whereas the failure modes in all gold coated systems were cohesive and adhesive, mainly cohesive. The three-point-bending test showed that the bonding strength of GS and GI groups [ （37. 08 ±4. 32） and （36. 20 ± 2.40） MPal were higher than those in uncoated groups[ （31.56 ± 3.74） and （30. 88 ± 2. 60） MPa, P 〈 0. 05 ], while no significant difference was found between T group and GT group（ P 〉 0. 05 ）. Conclusions The gold paste intermediate coatings can improve bond strengths of Super porcelain Ti-22 system and Initial Ti system, which have potential applications in clinical fields.