Development of New Precious Metal Alloys for Resin Bonding with Adhesive Metal Primer

开发了一种新型的含锌或含锡的牙科用贵重金属树脂粘接合金。采用硫代磷酸盐金属底漆，与牙胶粘剂具有良好的粘接性能。作者已申请日本专利（牙科用贵重金属合金粘合剂，H6-204145,1994）。本项目采用石英晶体微天平法、FT-IR和ESCA等分析方法对其粘附机理进行了研究。并对其在口腔修复和修复领域的临床应用进行了研究。结果表明：1)在新型贵金属合金与胶粘剂树脂的结合界面上，采用胶粘剂底漆获得了优异的耐水性能。含金60-70%的合金的耐蚀性不因母材中铜含量达到18%而降低。其耐腐蚀性可与14k金合金媲美。添加贱金属后，时效行为没有改变。2)采用ESCA对Au-In合金表面进行分析，建立其与粘接能力的关系。认为4-META树脂对纯金的粘附能力较差是由于表面化学吸附和物理吸附的H_2O分子所致。为了获得优异的附着力，对4-META具有化学亲和力的氧化物元素必须至少覆盖合金表面的50%。3)基于Bolger的酸碱相互作用，研究了4-META与金合金上形成的In_2O_3、ZnO和Sio等氧化物的化学相互作用，以更好地了解金属与4-META树脂的粘附机理。用氧化物的等电点和黏附单体的pK_A等电点讨论了极性表面相互作用。认为4-META与In_2O_3、ZnO和SnO的相互作用为离子相互作用，与SiO_2的相互作用为氢键。

New dental precious metal alloys containing In Zn, or Sn for resin bonding have been developed. Excellent adhesive ability with dental adhesive was obtained by using a thiophosphate metal primer. The authors have presented Japanese Patent (Adhesive Dental Precious Metal Alloys, H6-204145,1994). In the present project, adhesion mechanism was investigated by analytical methods including quartz crystal microbalance method, FT-IR,and ESCA.The application for clinical use was also studied in the field of prosthodontic and restorative dentistry. The results obtained were as follows :1) Excellent water durability at adhesion interface between adhesive resin and new precious metal alloys was obtained with adhesive primer. Corrosion resistant of alloys containing 60-70% gold was not decreased by adding of base metal up to 18% with copper. The corrosion resistance was comparable to commercial 14 K gold alloy. Aging behavior did not change by adding base metals.2) The Au-In alloy surface was analyzed by ESCA to establish the relationship with adhesive ability. It is considered that chemisorbed and/or physisorbed H_2O molecules on the surface caused the poor adhesive ability of 4-META resin to pure gold. To obtain excellent adhesion the element of an oxide having chemical affinity for 4-META must cover at least 50% on the alloy surface.3) Chemical interaction, based on Bolger's acid-base interaction, of 4-META with oxides such as In_2O_3, ZnO,and Sio formed on gold alloys was investigated to better understand the adhesion mechanism between metal and 4-META resin. Polar surface interaction was discussed with the isoelectric point of oxides and pK_A of adhesive monomer. The interaction of 4-META with In_2O_3, ZnO,and SnO was considered to be ionic, and hydrogen bonds were assumed with SiO_2.