BOND STRENGTH OF PORCELAIN TO METAL UNDER DIFFERENT FIRING ATMOSPHERES: comparision of bond strength of porcelain to non-precious metals coping under vaccum and argon atmospheres

Evaluation of porcelain-metal bond has been a subject of immense interest in the recent past and studies have proved that the optimal temperature and the atmosphere in which the porcelain is baked on to metal surface is of critical value. Several studies in past have been carried out to evaluate the porcelain metal bonds. These studies evaluate the bonding of porcelain with metal, compatibility of metal ceramic system, testing and thermomechanical compatibility and stresses in porcelain metal system. But, occasional chipping of porcelain from metal surface in PFM restoration have been the persistent problem till now.For Porcelain-fused to metal (PFM) restoration to be clinically successful, it must satisfy certain criterias. Vacuum firing of porcelain has yielded favourable results. This led to the thought that an inert atmosphere would produce better ceramo-metal bonding and because of this, firing of porcelain in an atmosphere of argon gas has evinced great interest, it seems pertinent to evaluate the bond strength of porcelain to non-precious metal copings under different firing atmospheres (vacuum & inert).