Denture Base Composition

Properties of Denture-Base Matena/s. Physical properties of acryflc denture-base materials are given in Table 12 (204). Mechanical properties of denture bases can vary considerably, and depend on composition, mode of polymerization, and degree of interaction with the oral environment. 

Caprolactone is claimed as a component in one-paste-type resin compositions for denture bases <2002JPP2002104912> and e-caprolactone copolymers are suggested as components in polyurethane-based multilayered artificial leather sheets <2004JPP2004250808, 2004JPP2004250809>. 

Thermal analyses of other dental polymers have also been reported. The compositions of waxes have been studied by differential thermal analysis (DTA) [64-66] and DMA [67], Conventional DSC and DMA recently showed the superiority of microwave-processed denture base resins to those processed by the slower traditional dental laboratory heating regimen [68], In contrast, comparisons of Tg and other relevant properties for a soft denture liner that was processed by the dental laboratory procedure and a more convenient chairside procedure indicated that both procedures yielded equivalent results [69],... 

Most of the dental composite resin materials and denture-base polymers are diluted with the less viscous difunctional acrylates. These are the met-hacrylic monomers of which EGDMA, DEGDMA, triethylene glycol dimethacrylate (TREGDMA) (Fig. 3) and 1,4-butanediol dimethacrylate (BUDMA) (Fig. 4) are the most widely used (Table 2). The use of acrylates in dentistry is an expanding field. Some are... 

Technique, J. Dental Res. 53(3), 1074 (1974). IPNs as denture-base materials. Celanese Coatings Company, Resin Compositions, Br. Pat. 1,205,682 (1970). Unsaturated polyester-styrene/epoxy SIN. 

Medicine. For years, dentures, dental fillings, and denture bases have been made using methacrylic ester polymers (129,130) (see DENTAL Materials). These polymers can also be used to prevent tooth decay in natural teeth by serving as a barrier which can be coated over the surface of the tooth. The dimensional behavior of these bone-cement composites has been reported (131) as has the structure of the cold-cured acrylic resin (132). Both hard and soft contact lenses have been made using polymethacrylates (133,134). hHYDROGELS (qv) comprising poly(2-hydroxyethyl methacrylate) are used in soft contact lenses (135,136). 

Wang, R., Tao, J., Yu, B., Dai, L. Characterization of multiwalled carbon nanotube—polymethyl methacrylate composite resins as denture base materials. J. Prosthetic. Dentistry. 

Ceramics for Replacement and Repair Ceramics are used as implants, for repairs and restorations in the human body. Hydroxyapatite-based compositions stimulate bone and tissue growth. Other ceramics that could be used for replacement and repair are alumina and zirconia. Teeth replacement has been the earliest use of ceramics in the human body. Prior to 1774, teeth of animals and those extracted from human donors were used, along with other materials such as ivory, bone, and wood. In 1774, porcelain was used. In recent years, ceramics have become the standard materials for tooth replacement, dentures, and restoration techniques. A composite of ceramic particles in a polymer is used to fill cavities. Jawbones are restored by hydroxyapatite. 

Subjects included are particulate filled composites (Abell/Crenshaw/ Turner), monomers (Antonucci, Griffith/O Rear, and Cowperthwaite/ Foy/Malloy), denture base polymers (Cornell) polymerization processes (Brauer and Kilian), and ionic polymers (VJilson and Belton/Stupp). The section concludes with three discussions of aspects of structure-property relationships (Draughn, Powers/Fan/ Craig, and DeVries/Knutson/Draughn/Reichart/Koblitz). 

A new denture base resin system which has an unusually high hydrophilic character has been marketed. This material consists, evidently, of a conventional poly(methyl methacrylate) and a monomer composition containing both methyl methacrylate and 2-hydroxyethyl methacrylate. 

Prosthetic composites (crown and bridge veneers and denture base resins) (5) are discussed elsewhere in this volume (6,7). It... 

Table 8. Composition of Base-Metal Alloys for Removable Partial Dentures, %...

Considerable activity is underway to develop nontoxic activator and accelerator systems for these room temperature curing reactive adhesives. It is of interest to note that progress in analogous systems has been made in dental research - in work on acrylic adhesives for repair and for acrylic dentures. In one of several papers ( ), workers describe compositions of complex, exotic acrylic monomers cured with standard and modified Schiff s bases and with complex aromatic amines. 

Silicone liners are similar in composition to the previously described elastomeric impression materials, which are produced by condensation pol5mieriza-tion. Systems for the relining application may be either a one-component system, which cures in the presence of moisture or heat, or a two-component system, containing base and catalyst. Both types generally have poor adhesion to the denture surface, and can readily support bacterial growth. 

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