دراسة مخبرية مقارنة للاختلاف اللوني لنوعين من الخزف المرتبط بالمعدن بعد تكرار خبز الخزف

Abstract EN

Background& Objective: Color stability is an important factor to ensure the long-term of esthetic success of ceramic restoration, there are several factors affect color stability, such as repeated firing.

Aim of Study: Color Difference comparison between two types of ceramic fused to metal after repeat firing by using spectrophotometer (Vita Easy Shade).

Materials & Methods: Twenty disc-shaped specimens (12mm in diameter, 2mm thickness) were fabricated from nickel chromium alloy (HI BOND), and two types of ceramic fused to metal (VITA VMK95,IPS classic),0.2mm opaque and 1mm of enamel and dentin ceramic, were applied on them ,after glazing and polishing the samples were fired 6 times.

Color measurement was carried out before and after firing by using spectrophotometer (Vita Easy Shade), the data were expressed in commission international I’Eclairage system coordinates (a*, b*,l*) then the results studied by using T-Student test At p<0.05 .

Results: The main color difference ∆E between two types of ceramics fused to metal (VITA VMK95, IPS classic) did not have statistical deference (p>0.05).

After repeat firing, however there were significant statistical difference (p<0.05) in l*,a* parameters of the two types of ceramic after repeat firing.

Conclusions: repeated firing did not result in significant color difference between two types of ceramic, however the main color difference in (VITA VMK95) was bigger than (IPS classic Ivoclar)