Improved design of long-span resin-bonded fixed partial dentures: three case reports

When single-tooth implants are not appropriate, the use of resin-bonded fixed partial dentures is a preferred treatment option when the abutments are relatively sound. However, the use of resin-bonded fixed partial dentures (RBFPDs) for replacing two or more missing teeth is considered to have a guarded prognosis, as long-span RBFPDs have been shown to be less successful than single pontic prostheses. The use of properly modified nonrigid connectors may well improve the success of long-span RBFPDs by reducing harmful interabutment stresses that appear to be responsible for retainer debonding in long-span RBFPDs. For such long-span prostheses, it is advised that the major retainer have wraparound on at least three surfaces of the abutment or have strategically placed opposing axial grooves or slots. It is considered essential that the connector allow interabutment movement in both the horizontal and vertical planes so that the retainer with the greater resistance and retention form does not stress and possibly debond the minor retainer. The upside-down positioning of the nonrigid connector and the matrix incorporated with the major retainer is considered important for successful maintenance, if a debond should occur due to greater loading on the major retainer, because it can be removed and recemented easily. Clinical cases are described that replace two or more missing teeth using fixed-movable RBFPDs with nonrigid connectors.