Denture Repair and Services

The basic repair of a complete denture is not for the inexperienced or untrained technician, no matter how simple it appears on the surface. The traumatic stress forces that a complete denture must endure in service are extreme. That potential repair site must be able to withstand and exceed that level of force and stress.

There are many factors to consider to prevent the failure of a denture repair site in service. The age and condition of the existing methyl methacrylate resin is a primary concern. If the existing resin is more than six years old (or it was originally subject to a low-temperature, pressure pot, fast cure curing protocol) there is a good chance that the residual monomer has dissipated completely and the original resiliency of the resin is depleted, thus causing embrittlement throughout the existing resin. In some instances stress cracks are visible at or just below the surface. By experience, this alone indicates that the existing resin would not be able to support a structural repair site.

An acceptable solution would be to re-base the denture either using heat or self-cure resin, but, process the procedure in a flask. In theory, any other base repair attempted would not be able to successfully endure the intraoral stresses of mastication. A denture repair could be successful as an instant temporary repair by bulking up the repair site with self- curing resin or placing a metal or fiberglass reinforcement. However, there is reason to believe that excessive bulk and discomfort would soon be reflected by the patients concerns and complaints.

The acrylic resin does not bond to metal unless the additional step of using acrylic solder, a 4-meta solution, is added, which does allow a tenacious bond between the acrylic and the metal. Always follow manufacturers technique. Fiberglass resin or fiberglass straps may provide additional support of the repair if applied correctly. The excess and prolonged run-off of monomer in repairing an acrylic denture will attack the existing base acrylic resin and soften the area affected. This could weaken the attachment/joint area of the repair site. Excess monomer should be removed by a Q- tip, or a gentle airstream blowing towards the suction collector. Be sure that a carbon filter is attached to the source to absorb the harmful MMR fumes.

The lingual aspect of a lower denture is especially vulnerable to fracture within the curve of the arch if that area is not of a substantial thickness, as the thinner acrylic resin does embrittle more quickly. While some techniques suggest that a metal (lingual) bar be placed in the area to reinforce the site, this is an area that may benefit more by a complete removal of all of the existing base resin and replace that with new, processed or heat cured resin in a modified re-base procedure, preferably in a flask. The self-cure resin processed in this manner is acceptable; however the physical properties may deteriorate sooner than processed acrylic.

A suggested solution to a complex base fracture, or multi-fractured, denture would be to reconnect or reassemble the broken pieces, impress, (PVS or Polysulfide), reline/rebase the denture to replace most, or all, of the existing embrittled resin. This would recapture some of the original resiliency of the denture as new, in addition to the new fit. This protocol will insure that the patient will not return to have the original repair repaired.