Int Poster J Dent Oral Med 2011, Vol 13 No 4, Poster 556
Compression tests on heat-curing dental resins
DMD PhD stud. Otilia Bolos, Prof. Dr. Cristina Maria Bortun, Adrian Bolos, DMD, PhD stud., Loreta Szabo, DMD, PhD stud., Simina Gaman, DMD, PhD stud.,
"Victor Babes" University of Medicine and Pharmacy, Timisoara, Romania
Anghel Cernescu, PhD student eng.,
Politehnica University, Timisoara,, Romania
May 5th 2010
2010 Annual Meeting of the Swiss Society for Biomaterials (SSB)
Empa Dübendorf, Switzerland
Complete dentures′ repairs are frequent at elderly patients. These dentures are made from different acrylic resins, which have different mechanical properties [1,2,3,].
Material and Methods
18 pairs of complete dentures were manufactured at Faculty of Dentistry Timisoara, using the classical technology. These were realized on the same model type, from different heat-curing dental resisns: Superacryl, Triplex, Vertex. A group of 6 pairs (2 from each material) were tested directly on the mechanical testing machine LBG 100T, other 6 had as support the plaster model and other 6 were adapted on models with help of silicone (Lastic Xtra, Kettenbach, Germany). The prostheses were tested at compression, until they broke, by applying forces on their occlusal surfaces.
|Fig. 1a: Mechanical testing machine LBG 100T
||Fig. 1b: Force applying detail
|Fig. 1c: Force applying detail
|Fig. 1d: Force applying detail
The results emphasized a rapid braking of the prostheses that didn't have any support; slower braking and multiple pieces fracture of plaster model and then that of the prostheses (Fig. 2b). The slowest fracture took place at prostheses adapted on model with help of silicone (Fig. 2a). The braking happened at 2,1 kN, as seen in the graphic below (Fig. 3b- on silicone). Figure 3a (without silicone, directly on model) shows the moment of model braking; by continuing the force application on denture′s occlusal surface, we notice a peak of its deterioration at 2,079 kN. Vertex material had the best behaviour, in all three situations.
|Fig. 2a: Fractured complete denture
||Fig. 2b: Fractured complete denture
|Fig. 3a: Compression load diagrams - denture is situated directly on model
||Fig. 3b: Compression load diagrams - denture is adapted on model by silicone
We can conclude that, by imitating the soft tissue with help of silicone, we are closer to the reality from the mouth. The more intimate adaptation to prosthetic field the prostheses have, the more resistant they are (from the mechanical resistance point of view). In case of using silicone, the compression resistance force was higher and, that way, it happened a slower braking in comparison with the case of applying the denture directly on model, as shown in diagrams above. Also, we observed that, denture′s mechanical beahviour is connected to resin′s properties.
- Diaz-Arnold AM, Vargas MA, Shaull KL, Laffoon JE, Qian F: Flexural and fatigue strengths of denture base resin. J Prosthet Dent. 2008 Jul; 100(1):47-51.
- D.L., Dixon, K.G. Ekstrand, L.C. Bredding, (1991). The transverse strengths of three denture base resins. J. Prosthet. Dent., 66: 510-513.
- G. Uzun, N. Hersek. (2002 Jul): Comparison of the fracture resistance of six denture base acrylic resins. J Biomater. Appl.; 17(1):19-29.
This study was supported by Ideas grant CNCSIS type A, no. 1878/2008 from Ministry of Education and Research of Romania.
This Poster was submitted by DMD PhD stud. Otilia Bolos.
DMD PhD student Otilia Bolos
"Victor Babes" University of Medicine and Pharmacy
University School of Dentistry, Specialization Dental Technology
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