Modified section method for laser-welding of ill-fitting cp Ti and Ni-Cr alloy one-piece cast implant-supported frameworks
| Autor: | Renata Cristina Silveira Rodrigues, M da G Mattos, Ricardo Faria Ribeiro, Rodrigo Tiossi, F. A. Aguiar Júnior, Hilmo Barreto Leite Falcão-Filho |
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| Rok vydání: | 2010 |
| Předmět: |
Dental Prosthesis Repair
Materials science Alloy Diagonal Passivity chemistry.chemical_element Welding engineering.material Statistics Nonparametric law.invention Dental Prosthesis Retention Optical microscope Nickel law Prosthesis Fitting Humans General Dentistry Titanium Analysis of Variance Dental Casting Technique Lasers Metallurgy Laser beam welding Dental Prosthesis Design chemistry Casting (metalworking) engineering Denture Partial Fixed Chromium Alloys Dental Prosthesis Implant-Supported Dental Soldering |
| Zdroj: | Journal of Oral Rehabilitation. 37:359-363 |
| ISSN: | 1365-2842 0305-182X |
| DOI: | 10.1111/j.1365-2842.2010.02063.x |
| Popis: | This study aimed to verify the effect of modified section method and laser-welding on the accuracy of fit of ill-fitting commercially pure titanium (cp Ti) and Ni-Cr alloy one-piece cast frameworks. Two sets of similar implant-supported frameworks were constructed. Both groups of six 3-unit implant-supported fixed partial dentures were cast as one-piece [I: Ni-Cr (control) and II: cp Ti] and evaluated for passive fitting in an optical microscope with both screws tightened and with only one screw tightened. All frameworks were then sectioned in the diagonal axis at the pontic region (III: Ni-Cr and IV: cp Ti). Sectioned frameworks were positioned in the matrix (10-Ncm torque) and laser-welded. Passive fitting was evaluated for the second time. Data were submitted to anova and Tukey-Kramer honestly significant difference tests (P0.05). With both screws tightened, one-piece cp Ti group II showed significantly higher misfit values (27.57 +/- 5.06 microm) than other groups (I: 11.19 +/- 2.54 microm, III: 12.88 +/- 2.93 microm, IV: 13.77 +/- 1.51 microm) (P0.05). In the single-screw-tightened test, with readings on the opposite side to the tightened side, Ni-Cr cast as one-piece (I: 58.66 +/- 14.30 microm) was significantly different from cp Ti group after diagonal section (IV: 27.51 +/- 8.28 microm) (P0.05). On the tightened side, no significant differences were found between groups (P0.05). Results showed that diagonally sectioning ill-fitting cp Ti frameworks lowers misfit levels of prosthetic implant-supported frameworks and also improves passivity levels of the same frameworks when compared to one-piece cast structures. |
| Databáze: | OpenAIRE |
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