The Impact of Sandblasting and Primer on the Bond Between Cements and Metal Framework

Disintegrating the adhesive bridge from the abutment is one of the most uncomfortable consequences for the patient, and especially for the therapeutist, as it arises a question on the justifiability of the applied method. The success of these appliances depends on the design of the metal skelet, the strenght of the cement itself, as well as its bonding with the etched enamel and the dental alloy. However, because of the weak affinity of one material to the other and higher strain at the interface cement-alloy, the bond cement-alloy is weak. The aim of the undertaken investigation was to identify which combinations of sandblasting and primer achieve maximum torque strength values of the bond between cement and corresponding Ag-Pd part of sample. In order to minimize the number of variables in the experiment, so that the strength of the bond cement-alloy represents a real indicator of the efficiency of the cement bond on the metal sample, the metal-cementmetal test model was used. 180 completely equal metal samples were tested, divided in groups and subjected to various methods of conditioning. Bonding strength values obtained through various combinations of mechanical-chemical type of bonds of three kinds of cement with AgPd alloy were tested, while structural investigations of the break area were accomplished by means of the polarizing microscope and the microanalyzer of the view. The bonding strength values of the cement-alloy bond were determined by measuring the load at the instant of the bond break. The results were statistically analyzed by three-way variance analysis, and then processed by one-way variance analysis and/or compared by means of the Tukey test. The active group of the V-Primer and the functional monomers of Panavia 21 and Super-Bond improved the characteristics of the bond of adhesive cements on the semi-precious surface, sandblasted by abrasives, while the worst results and adhesive breaks characterise ABC cement.