Effect of thermal cycling on denture base and autopolymerizing reline resins

Abstract

Objective:This study evaluated the fracture toughness (FT) of denture base and autopolymerizing reline resins, with and without thermocycling (T). Material and Methods:Specimens of each material (denture base acrylic resin - Lucitone 550 - L; autopolymerizing reline resins - Ufi Gel Hard-UH, Tokuyama Rebase II-TR, New Truliner- NT and Kooliner-K), were produced, notched and divided into two groups (n=10): CG (control group of autopolymerizing reline resins and L): FT tests were performed after polymerization; TG (thermocycled group): FT tests were performed after T (5ºC and 55ºC for 5,000 cycles). Results:Results (MPa.m(1/2)) were analyzed by two-way ANOVA and Tukey's test (p=0.05). L exhibited the highest FT mean values in both groups (CG - 2.33; TG - 2.17). For the CG groups, NT showed the highest FT (1.64) among the autopolymerizing reline resins, and K the lowest (1.04). After T, when the autopolymerizing reline resins were compared, a statistically significant difference in FT was found only between the NT (1.46) and TR (1.00). Conclusions:Thermocycling increased the FT of K and did not influence the FT of L, UH, TR and NT.

Impact of different surface treatments and repair material reinforcement on the flexural strength of repaired PMMA denture base material

“…In the oral cavity, moisture contamination and thermal fluctuation facilitate absorption of water 21) . Absorbed water along with the changes in temperature, may cause degradation of denture polymer 20) . When water molecules penetrate the PMMA mass, they occupy inter-polymeric spaces, forcing the polymer chains apart and affecting the mechanical properties of the resin 20,38) .…”

“…Over time with intra-oral use, denture base and auto-polymerized repair resin are exposed to a wet environment with fluctuating temperatures 20) . It is essential, therefore, to explore whether these changes in oral temperatures would affect the mechanical properties of repaired dentures.…”

“…Inclusion of thermal cycling test has been recommended as part of the testing protocol for denture base materials to simulate intra-oral conditions. Thermal cycling involves subjecting the tested materials to temperature extremes using temperature controlled water baths in a lab setting 20,21) .…”

Gümüş Zeoli̇t İlave Edi̇len Akri̇li̇k Rezi̇nleri̇n Eği̇lme Dayanimlarinin i̇n-Vi̇tro Değerlendi̇ri̇lmesi̇

“…Isıl döngü işleminin neden olduğu mekanik değişimlerin klinik açıdan yaratacağı etkilerin daha ileri araştırmalarla desteklenmesi gerekmektedir. 33,34 MURAT J Dent Fac Atatürk Uni Cilt:28, Sayı:4, Yıl: 2018, Sayfa, 539-544 543 Araştırmamızın sonuçlarına göre; düşük yüzdelerde akrilik rezinlere ilave edilen zeolitlerin mikroorganizmalara karşı etkili olabilmesi nedeniyle özellikle protezlerini yeteri kadar temizleyemeyen hastalarda mekanik özellikler üzerindeki etkisi daha az önemli olabilmektedir. Nitekim sonuçlarımıza göre; en fazla % 4 oranında ilave edilen zeolitin akriliğin mekanik özelliğini standart kabul edilen sınırın üstünde bir değere kadar zayıflattığı tespit edilmiştir.…”

Biocompatibility of a titanium dioxide‐coating method for denture base acrylic resin

“…Polymethyl methacrylate (PMMA) resin has long been used as a denture base material 1 , because of its hardness and rigidity under masticatory pressure, ease of handling, good aesthetics and low price. However, despite its obvious suitability as a denture base material 2,3 , PMMA is also susceptible to deterioration 4 , surface roughness following fatigue, microbial adherence [5][6][7] and colonisation by bacteria due to water absorption 1 .…”