RESUMO
The purpose of this study was to evaluate cervical mistifing of casting full metal crowns according to investment techniques using commercial available alloys made from silver stannum. Fifteen metal full crowns were obtained through stainless steel die with full crowns preparation, included into three groups as follows: conventional technique, vacuum technique and pressure technique. Readings of cervical disagreement were made through a comparing microscope increased 45 x and each crown was measured in 4 different regions (vestibular, lingual mesial and distal). This way it was verified which of the techniques proposed would balance the casting shrinkage for the silver-stannum alloy used. From the results obtained we conclude that the best cercical adaptation was the one got through pressure technique.
Assuntos
Coroas , Ligas Dentárias , Revestimento para Fundição Odontológica , Técnica de Fundição Odontológica , Infiltração Dentária/etiologia , Prata , EstanhoRESUMO
The work aims to investigate the influence of positive pressure to initial and final setting time, as well as the volume variation in course of the pressure carried out gypsum-bonded investment found at Dental Commerce. Seventy-six test samples were obtained, being five of them through conventional investing technique and seventy-one through technique by pressure. Gillmore needles were employed for determining the setting time, meanwhile for volumetric variation a mathematic formula had been applied. According to results, it was concluded that the use of positive pressure affected the initial and the final setting time and the volume after set.