The influence of mold temperature on the fit of cast crowns with commercially pure titanium
| Autor: | Edwin Fernando Ruiz Contreras, Guilherme Elias Pessanha Henriques, Wagner Sotero Fragoso, Marcelo Ferraz Mesquita |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2005 |
| Předmět: |
Materials science
medicine.medical_treatment chemistry.chemical_element medicine.disease_cause Crown (dentistry) Statistics Nonparametric Traveling microscope Mold Materials Testing medicine Dental Casting Technique Animals Dental casting investment General Materials Science Composite material Titânio Titanium Commercially pure titanium Crowns Temperature Adaptação marginal Revestimento para fundição odontológica Grinding chemistry Dental Casting Investment Thermodynamics Cattle Coroas Castability Marginal adaptation/Dentistry Marginal adaptation |
| Zdroj: | Brazilian Oral Research v.19 n.2 2005 Brazilian Oral Research Sociedade Brasileira de Pesquisa Odontológica (SBPqO) instacron:SBPQO Brazilian Oral Research, Volume: 19, Issue: 2, Pages: 139-143, Published: JUN 2005 |
| Popis: | Commercially pure titanium (CP Ti) has been widely applied to fabricate cast devices because of its favorable properties. However, the mold temperature recommended for the manufacture of casts has been considered relatively low, causing inadequate castability and poor marginal fit of cast crowns. This study evaluated and compared the influence of mold temperature (430°C - as control, 550°C, 670°C) on the marginal discrepancies of cast CP Ti crowns. Eight bovine teeth were prepared on a mechanical grinding device and impressions were used to duplicate each tooth and produce eight master dies. Twenty-four crowns were fabricated using CP Ti in three different groups of mold temperature (n = 8): 430°C (as control), 550°C and 670°C. The gap between the crown and the bovine tooth was measured at 50 X magnification with a traveling microscope. The marginal fit values of the cast CP Ti crowns were submitted to the Kruskal-Wallis test (p = 0.03). The 550°C group (95.0 µm) showed significantly better marginal fit than the crowns of the 430°C group (203.4 µm) and 670°C group (213.8 µm). Better marginal fit for cast CP Ti crowns was observed with the mold temperature of 550°C, differing from the 430°C recommended by the manufacturer. O titânio comercialmente puro (Ti c.p.) tem sido largamente empregado na elaboração de estruturas protéticas fundidas devido às suas propriedades favoráveis. Entretanto, a temperatura do molde recomendada pelo fabricante tem sido considerada baixa, causando inadequada fundibilidade e precária adaptação marginal de coroas fundidas. Este estudo avaliou e comparou a influência de temperaturas do molde (430°C - como controle, 550°C, 670°C) na discrepância marginal de coroas fundidas em Ti c.p. Oito dentes bovinos foram preparados em um torno mecânico e moldados para produzirem oito modelos-mestre. Vinte e quatro coroas foram confeccionadas em Ti c.p. para três grupos de temperatura do molde (n = 8): 430°C (como controle), 550°C e 670°C. A fenda marginal entre a coroa e o dente bovino foi observada em microscópio mensurador (50 X). Os valores de adaptação marginal das coroas fundidas em Ti c.p. foram submetidos ao teste de Kruskal-Wallis (p = 0,03). O grupo fundido a 550°C (95,0 µm) exibiu adaptação marginal significativamente melhor que as coroas dos grupos 430°C (203,4 µm) e 670°C (213,8 µm). Foi observada melhor adaptação marginal das coroas fundidas em Ti c.p. com a temperatura do molde a 550°C, diferindo da temperatura recomendada pelo fabricante, de 430°C. |
| Databáze: | OpenAIRE |
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