The next and most recent milestone in the denture base field was the introduction of acrylic resin to the dental profession in 1936. It is estimated that 99% of all complete denture are fabricated with one of the acrylic resins. Most acrylic resin denture bases produced currently are made from polymethyl methacrylate, which is a polymer consisting of structural mer units derived from methyl methacrylate. Most modern acrylic resins contain a cross-linking agent in the monomer (such as glycol dimethacrylate), which provides resistance to crazing.
The advantages of the acrylic resins are 1) excellent esthetics 2) easy and simple to mold and press 3) easy to repair, reline, rebase and adjust 4) dimensionally accurate and stable (processing change is usually less than 0.5% or 0.2un) 5) inexpensive and adequate strengh in most situations, barring sudden impact etc. However, the disadvantages are 1) poor thermal conductor 2) nonwettable surface may decrease possible retention, food may cling to surface 3) relatively low modulus of elasticity and high coefficient of tliermal expansion etc.
All acrylic resin denture baes contain 0.2 to 0.5% residual monomer after processing. It is difficult to see any connection between denture sore mouth and residual monomer. Practially all denture sore mouths are caused by trauma. Allergy to acrylic resin denture base materials is very rare.
The physical and mechanical properties of denture base materials do not decline on aging. Serviceability of dentures, however, is often lessened by resorptive changes of the osseous alveolar processes. These changes cause a gradual deterioration in centric and eccentric occlusion and a decrease in face height.
The purpose of this study was to investigate the kinds, characteristics, changes and biological properties of acrylic resin denture base material.
|