[A comparison of the adhesive strength of unaged and aged metal-resin bonding systems. An in vitro study].
The tensile strength and shearing strength of six bonding systems for the acrylic resin to metal bond were tested, unaltered and after cyclic thermal shock. The methods were 1) sandblasting with 50 mu and 2) 250 mu aluminium oxide granules, 3) electrolytic etching, 4) the RBS system, 5) the Sebond-MKV system, and 6) silicoating with the Kulzer Silicoater system. The materials to bond were Paladur, an autopolymerizing methacrylate, and the cobalt chromium alloy Wisil M. It was found that sandblasting gave good constant results depending on the size of the Al2O3 granules. RBS did not improve the tensile strength. The other tested systems improved the average values by a factor 3.5 in comparison to sandblasting. Silicoating showed a wide scattered range. The values of Sebond were increased and constant. After thermocycling the values were up to 30% better, but only when the recommended opaquer was not used. Sandblasting could give a good reference as baseline for comparative studies.