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

已开发出用于树脂粘结的含In、Zn或Sn的新型牙科贵金属合金。使用硫代磷酸盐金属底漆，可获得与牙科胶粘剂的良好粘接能力。作者提交了日本专利（牙科用粘合性贵金属合金，H 6 - 204145，1994）。本课题采用石英晶体微量天平法、红外光谱法、电子能谱法等分析方法研究其粘附机理，并探讨其在口腔修复领域的临床应用。结果表明：1）粘接底漆使粘接树脂与新型贵金属合金的粘接界面具有良好的耐水性。含60-70%金的合金的耐腐蚀性不因基体金属中加入高达18%的铜而降低。耐腐蚀性与商业14 K金合金相当。加入基体金属后，合金的时效行为没有发生变化。2）通过ESCA分析，研究了Au-In合金表面与基体结合能力的关系。认为4-Meta树脂对纯金的吸附能力差是由于其表面化学吸附和/或物理吸附了H_2O分子所致。为了获得良好的附着力，对4-Meta具有化学亲和性的氧化物元素必须在合金表面至少覆盖50%。3）基于Bolger酸碱相互作用，研究了4-Meta与金合金表面形成的氧化物如In_2O_3、ZnO和SiO的化学相互作用，以更好地理解金属与4-Meta树脂之间的附着机理。用氧化物的等电点和粘合剂单体的pK_A讨论了极性表面相互作用。4-Meta与In_2O_3、ZnO和SnO的相互作用被认为是离子型的，与SiO_2的相互作用被认为是氢键。

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.