Original scientific paper
https://doi.org/10.15644/asc51/4/5
The Influence of Thermocycling on the Flexural Strength of a Polyamide Denture Base Material
Nick Polychronakis
; Removable Prosthodontics, Dental School, National and Kapodistrian University of Athens, Greece
Aspasia Sarafianou
; Department of Prosthodontics, Dental School, National and Kapodistrian University of Athens, Greece
Alkibiadis Zissis
; Removable Prosthodontics, Dental School, National and Kapodistrian University of Athens, Greece
Triantafillos Papadopoulos
; Department of Biomaterials, Dental School, National and Kapodistrian University of Athens, Greece
Abstract
Objective: The aim of the present study was to evaluate the influence of thermocycling on the flexural
strength of a polyamide base denture material. Materials and methods: A polyamide denture base
material (Valplast) was tested, whereas a PMMA material (Vertex) was used as a control. Thirty specimens
of each material were fabricated for flexural strength testing according to ISO 1567. They were
prepared and stored in water at 37°C for 48 hours. The specimens of each material were divided into
three equal groups (n=10). Flexural strength testing was performed immediately after water storage
and after thermocycling (5°C / 55°C, 2 c/min) for 3000 and 5000 cycles. A three point flexural test
was performed on a universal testing machine at a crosshead speed of 5 mm/min. The final flexural
strength was calculated using the formula: FS = 3 PL/2 bd2. A two-way ANOVA with post-hoc analysis
using Tukey’s procedure was applied at .05 level of statistical significance. Results: A statistically significant
reduction in flexural strength was recorded after thermocycling at 3000 cycles for PMMA and
at 5000 cycles for both materials. The flexural strength of PMMA was significantly higher compared
to polyamide for all the conditions tested (p<0.05). Conclusion: Thermocycling had a significant adverse
effect on the flexural strength of polyamide and PMMA denture base materials.
Keywords
Denture bases; Flexural Strength; Resins, Synthetic; Polyamide; Nylons; Materials Testing
Hrčak ID:
190891
URI
Publication date:
18.12.2017.
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