Η επίδραση της θέσης των αγωγών απαέρωσης του χρόνου και του τρόπου χύτευσης στη δημιουργία πόρων και στη διάβρωση των χυτών

The porosity is one of the most important problems in making dental castings. There are a lot of factors which are involved in this problem. Three of them were examined in this study. These are the existance and position of the vent sprues, the type of casting machines and the time of castingpreheating the mold in the furnace and their influence in porosity. I used a Pd-Ag alloy for metalceramic constructions and cast 32 samples which were equivalent bridges, for they were reproduced from one metallic bridge sample. These 32 samples were arranged in four main groups of 8 samples each, according to the position of vent sprues. Each main group had 2 sub-groups of four samples each, according to the type of casting machine and the casting technique (The way). Each subgroup had two pairs of samples and one pair was immediately after preheating and the other 10 minutes later (The time). The 32 samples were examined under a metallographic microscope. I observed the porous in three different areas: the deposit, the cast mass and the aera pontic and crown connection. I chose 8 samples out of 32, in which four were from the main groups and the other four were all the samples of one sub-group. I used the Oldham-Mansfeld method to observe their resistance in corrosion. The results of this study showed that the castings which had vent sprues, had less porous than the castings without vent sprues. The castings that had the vent sprues on pontic-crown connection had less porous than the others. The results of casting resistance in corrosion depended on quantitative distribution of porous. That means the castings with the most porous had a low resistance in corrosion and the opposite.

Grantor dc:publisher

National and Kapodistrian University of Athens

Year dc:date

1986

Authors dc:creator

• Papadopoulos, Triantafillos
• Παπαδόπουλος, Τριαντάφυλος

• Αγωγοί απαέρωσης
• Διάβρωση οδοντιατρικών χυτών
• Πόροι οδοντιατρικών χυτών
• Χύτευση
• Casting
• Corrosion of dental castings
• Porosity of dental castings
• Vent sprues
• Ιατρική και Επιστήμες Υγείας
• Κλινική Ιατρική
• Medical and Health Sciences
• Clinical Medicine

Language dc:language

gre

Identifier

10.12681/eadd/0018

OAI identifier oai:identifier

oai:10442/0018