Evaluation the retention of upper complete denture with different acrylic denture base materials

Objective: to evaluate the retention of thermoplastic upper complete denture versus heat cured upper complete denture
Abstract: Successful denture is affected by altered biomechanical phenomenon of support, stability and retention. Polymethyl-methacrylate (PMMA) has been used to construct the dentures for ages. Some problems were described with these prosthesis that lead to fracture and allergy to methyl methacrylate monomer. The introduction of the nylon-derived denture base materials in 1950s smooth the way for a new type of dentures. It was found that soft dentures are excellent alternate to traditional hard-fitted dentures. Several advantages to flexible dentures over the traditional rigid denture bases were noted like translucency of the material that picks up the underlying tissue tones.
Material and methods: Fourteen completely edentulous patients were randomly divided into two groups. Group I received thermoplastic upper complete denture. Group II received heat cured upper complete denture. a readymade metallic bar was attached to the contact area between upper second premolar and upper first molar bilateral using self-cure acrylic resin, its center coincide with the geometrical center of the denture. Retention was measured using digital force gauge Retention force was measured as the maximum force needed to completely dislodge the maxillary denture. This step was repeated three times, three readings were taken and the average was recorded for each patient in both groups. The measurements were taken after 1 week of denture insertion and repeated 1, 3, 6 months after denture delivery.
Results: group I showed a little increase in denture retention than group II at the time of denture insertion, 1 and 3 months after but after 6 months it showed marked decrease in the denture retention. On the other hand the group II showed increase in the denture retention at time of denture insertion, 1 and 3 months after with slight decrease after 6 months.
Conclusion: The use of thermoplastic and heat cured acrylic resin has no significant difference regarding the denture retention. The time intervals for denture retention showed increase in denture retention regarding the time factors .