Evaluation and assessment of bonding of heat cure acrylic resin to cobalt-chromium alloy: Old ideas employing newer concepts

Literature has evidenced marvelous work on increasing bond strength between acrylic resin and partial denture casting alloys in past by various pioneer workers. Several systems have been employed to increase the bond strength between acrylic resin and partial denture casting alloys. Some of the popular methods were silicate layer silane coupling agents, active acrylate monomers: Polyfluormetacrylate bonding agents, tin oxide layer, and bifunctional monomer (dual function group). With the exception of air abrasion, most techniques are associated with expensive equipment, technique sensitivity, and harmful chemicals. Air abrasion, however, consistently has been associated with improved bond strengths. Traditionally, denture base acrylic resin is attached to the metal framework by three types of retentive aids: Mechanical, chemical, or combination of both. Advantage of retentive elements weakens the acrylic resin base by creating stress and by replacing its bulk on which resin depends for strength. Failure of the resin at the interface is a common source of problems when forces exceed the capacity of the retentive mechanisms. Here, authors have sought to review the bonding strength between acrylic resin and partial denture casting alloys along with their clinical applicability that can best retain the said prosthesis with minimal failure.