Effect Of Fractured Porcelain Surface Treatments On The Bond To Composite

Fracture of dental porcelain due to several reasons during its serving period is a common problem in clinical dental practice, which poses an esthetic and functional dilemma to reduce use-value greatly. For the bonded restorations, it is arduous to remove them from the mouth in case the accident occurs. Therefore intro-oral repair using light curing composite resins can be a simple and convenient alternative. Whether base metal alloy is exposed or not, surface pretreatment is not negligible in durability of repaired porcelain restoration, in this study several surface treatments are applied in light of respective characters of porcelain and alloy. By the measurement of shear bond after the thermal and cool water cycling experiment combined with the surface obersevation by SEM, try available substitute for HF with 1.23%APF or Nd:YAG laser in porcelain surface etching, discuss the optimum surface treatment and evaluate the effect of organosilane and function monomer on the bonding efficiency.The results are showed below:1. The shear bond strengths are high for the bonding of light-cured composite resin to treated porcelain surface and organosilane is helpful for getting higher bondstrength and lower microleakage. The 1.23%APF gel and the Nd:YAG laser can replace 8%HF to pretreat the fractured porcelain surface for bonding with compsite resin at appropriate parameter conditions.2. Either rganosilane or function monomer in bonding system perform full function by covalent bond formation with the compact oxides of base metals . in the event that exfoliated porcelain veneer of metal pocelain restoration needs repairing with composite resin, the remanent porcelain and the oxides of alloy surface should be kept by all means to gain ideal effect of bond.