チタン精密鋳造によるインプラント上部構造製作の検討

―添加膨張剤を利用した試作埋没材の適用について―

抄録

Gold alloy has been normally chose for fabricating superstructures on dental implants because of easy manufacturing and good fit. The aim of this study was to apply titanium castings for those restoration. Three kinds of commercial investment for titanium (Titavest CB, code:CB, Titanmold, code:TM, T-invest, code:TI) and an experimental calcia mold (code:CaO) were investigated and used for castings. Using a metal die for fabricating the full crown, fit of each MOD crown obtained from investments was evaluated.
Results were as follows:
1. MOD crowns obtained from CaO mold and CB were unnecessary to sandblast due to less reaction at casting. However, fused mold components were observed on the surface of those from TM and TI.
2. CB showed the largest thermal expansion in the investment tested although it was found to contract at setting. The value of total expansion was approximately 2.3%.
3. The thermal expansion of CaO depended on additional expander. In this study, sound castings with an excellent fit were fabricated when the mold was expanded about 1.6%.
4. MOD crowns obtained from commercial investments were not good enough on the fit. It from CB was oversized, and those from TM and TI were undersized.