EVALUATION OF PORCELAIN SURFACE TREATMENTS AND AGENTS FOR COMPOSITE-TO-PORCELAIN REPAIR

Intraoral repairs often involve bonding composite to fractured porcela in, Newer adhesive systems, currently referred to as multipurpose syst ems, include materials with recommended procedures for repair of porce lain. This laboratory study evaluated various treatment regimens with the ProBond adhesive system. Three different porcelain surface procedu res were used: (1) air abrasion with aluminum oxide (50 mu m), (2) 8% hydrofluoric acid, and (3) air abrasion and hydrofluoric acid. Eight d ifferent treatment procedures were then used to bond 10 composite cyli nders to porcelain surfaces in each group. Shear bond strengths (in me gapascals) were determined with an Instron testing machine after stora ge in water for 24 hours at 37 degrees C and after 3 months of storage and thermocycling, The combination of air abrasion and hydrofluoric a cid on porcelain surfaces before bonding composite recorded the most c onsistently effective bond strengths. Four of the treatment regimens i n the air abrasion groups yielded low bond strengths at 3 months, This study also indicated that silane treatment of porcelain is critical f or development of suitable bond strengths for composite.