J Korean Acad Prosthodont.  2000 Aug;38(4):461-471.

Effect of Degassing Condition on Ceramic Bond Strength of Ni-Cr Alloys

• Lee EH
• Jeon YC
• Jeong CM
• Lim JS

Abstract

This study evaluated the effect of dagassing on the ceramic bond strength of two Ni-Cr alloys under varying holding time at the upper limit temperature and atmospheric conditions. Metal specimens were divided into 5 groups for each alloy according to degassing conditions prior to porcelain application : no degassing, degassing under vacuum without hold, degassing under vacuum with hold for 5min. and 10 min. respectively at the upper limit temperature and degassing in air. Total number of metal ceramic specimens was eighty and each group had eight specimens : The ceramic bond strength was measured by four-point flexural test using Instron and the fractured surface was examined under SEM. The results obtained were as follows. 1. Degassing in air improved the ceramic bond strength of Ni-Cr alloys. 2. in degassing under vacuum, hold at the upper limit temperature was advantageous to the ceramic bonding of Ni-Cr alloys. 3. After ceramic metal bond test, metal surfaces were partially covered with the thin porcelain layer, and the cohesive failures in porcelain were predominant in groups showing higher ceramic bond strength.

MeSH Terms

Alloys*
Ceramics*
Dental Porcelain
Vacuum
Alloys
Ceramics
Dental Porcelain