- 作者：Renata Cristina Silveira Rodrigues ; DDS ; MSc ; PhD ; renata@forp.usp.br ; Elanio Pereira de Almeida ; DDS ; Adriana Clá ; udia Lapria Faria ; DDS ; MSc ; PhD ; Ana Paula Macedo ; MSc ; Eng ; Maria da Gloria Chiarello de Mattos ; DDS ; MSc ; PhD ; Ricardo Faria Ribeiro ; DDS ; MSc ; PhD
- 关键词：Titanium ; Dental casting investment ; Radiography ; Microscopy
- 刊名：Journal of Prosthodontic Research
- 出版年：2012
- 出版时间：January 2012
- 年：2012
- 卷：56
- 期：1
- 页码：58-64
- 全文大小：1025 K
Purpose
The aim of the present study was to evaluate commercially pure titanium (CP Ti) casting quality when a specific to titanium and a conventional phosphate bonded investments were used under different mold temperatures. For this, the evaluated parameters were surface roughness, bending strength, Vickers microhardness, casting quality by radiographies and microstructure of CP Ti.Methods
Wax patterns (28 mm ¡Á 3 mm ¡Á 1 mm) were invested using two phosphate bonded investments: Rematitan Plus (REM), specific to titanium, and Castorit Super C (CAS), a conventional investment, fired and cooled until reaching two mold temperatures: 430 ¡ãC (430) and room temperature (RT). Specimens were cast from CP Ti by plasma. After casting, specimens were radiographically examined and submitted to Vickers microhardness, roughness and bending strength evaluation. Microstructure was analyzed in the center and at the surface of specimen.
Results
Qualitative analysis of radiographs showed that specimens which were cast using CAS-RT presented more casting porosities while the specimens which were cast with REM-430 did not present any casting porosity. No significant difference was noted among the groups in the surface roughness and Vickers microhardness data, but the bending strength of the specimens cast using CAS was greater than REM groups. The microstructure of the specimens of the different groups was similar, presenting a feather-like aspect.
Conclusion
Casting porosities found in the specimens cast using conventional investments (CAS) and lower mold temperatures would limit their use, even mechanical properties were similar than in specimens cast using specific to titanium investment (REM) at temperatures recommended by the manufacturer.