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

研制了一种用于树脂粘结的含锌、锡的牙科贵金属合金。使用硫代磷酸盐金属底漆可以获得良好的牙科粘接剂粘接能力。作者提交了日本专利(粘附性牙科贵金属合金，H6-204145,1994)。本课题采用石英晶体微天平、FT-IR、ESCA等分析方法对粘结机理进行了研究，并探讨了其在口腔修复和修复领域的临床应用。结果表明：1)使用粘结剂底漆后，粘接树脂与新型贵金属合金粘接界面具有良好的耐水性。在含金60-70%的合金中加入18%的铜，不会降低合金的耐蚀性。其耐腐蚀性与市售14K金合金相当。2)用ESCA对Au-In合金表面进行了分析，以确定其与粘接性能的关系。认为表面化学吸附和/或物理吸附的H_2O分子导致4-Meta树脂对纯金的粘接能力较差。为了获得良好的附着力，对4-金属具有化学亲和力的氧化物元素必须在合金表面覆盖至少50%。3)为了更好地理解金属与4-金属树脂之间的粘接机理，基于Bolger酸碱相互作用，研究了4-金属与金合金表面形成的氧化物In_2O_3、ZnO、SiO的化学相互作用。用氧化物等电点和粘合单体的pK_A讨论了极性表面相互作用。4-META与In_2O_3、ZnO、SnO的相互作用被认为是离子相互作用，而与SiO_2的作用假定为氢键。

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.