STUDY OF FELDSPATHIC DENTAL PORCELAIN

Aesthetic revolution in restorative dentistry spins around the development of suitable ceramic materials. Though feldspathic porcelain holds promise as one of the best options due to its aesthetic, durability and biocompacibilty, its application is limited since the strength is relatively low. Dispersion strengthening controlled crystallisation and surface heat treatment have been reported in literature to improve the strength. In the present investigation, feldspathisc dental porcelain (Vivodent PE, Ivoclar, licherstein) with potash to soda ratio 2:1 was used as the starting material. Discs prepared by uniaxial pressing and sintered at 960°C in vacuum were strengthened by, i. Exchanging sodium ion with potassium ion at temperature above and below glass transition temperature, ii. Annealing and iii. Dispersion of PSZ. The results showed that the annealed samples showed significant strengthening followed by ion-exchanged samples. The results are analysed with different strengthening mechanisms.