scholarly journals Physical Properties of Polyamide-12 versus PMMA Denture Base Material

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mieszko Wieckiewicz ◽  
Volker Opitz ◽  
Gert Richter ◽  
Klaus W. Boening

Objectives.Polyamide-12 (PA) is a flexible material suited for denture bases and clasping. This study investigated its potential aging effects with a focus on surface roughness, color stability, and elasticity.Methods.PA specimens (Valplast) of40×10×2 mm and equally measuring PMMA specimens (Palapress) as control were fabricated. Color changes after storage in air, water, coffee, and red wine(n=10)were measured using the CIEL*a*b*color specification. Elasticity after thermocycling (1000, 3000, and 7000 cycles,  n=15) was measured by three-point bending testing. Mean surface roughness (Ra) was determined after storage in the liquids mentioned above and thermocycling(n=10).Results.Tukey’s HSD test(P<0.05)revealed statistically significant color changes of PA in red wine (ΔE=4.27after 12 days,ΔE=6.90after 12 days) and coffee (ΔE=3.93after 36 days) but no color changes in PMMA. Elastic modulus of PA was 845 MPa and not affected by thermocycling (Tukey's HSD test,  P>0.81). Dry specimens showed significantly decreased elasticity(P<0.001). Mean surface roughness (PA 0.20 μm, PMMA 0.28 μm) did not change significantly after thermocycling or storage (Mann-WhitneyU-test,  0.16<P<0.65).Significance. PA exhibited a higher susceptibility to discoloration than PMMA. Neither surface roughness nor elasticity of PA was altered by artificial aging.

2015 ◽  
Vol 1088 ◽  
pp. 519-525
Author(s):  
Hua Li Huang ◽  
Dan Feng ◽  
Hai Huan Gong ◽  
Ai Yang Song ◽  
Song Zhu

Heat-cured denture base resin is an important component in removable partial dentures and complete dentures, and has been widely used in the clinic. However, during long-term use, its appearance may be affected by varying degrees of color change, affecting the appearance and longevity of the dentures. In this study we examined the color changes and water absorption and solubility of dental base resins to investigate the color stability of four types of resin materials: New Century, Heraeus, Nissin and BASIS-HI. They were soaked in artificial saliva (as control), red wine, cola, coffee and tea separately at 37°C for 1, 4 or 12 weeks. Results are presented on which the color changes of dental base resin materials were associated with different denture base resins, soak solutions and storage times. We found that most of the dental resins became darker at prolonged immersion time. Heraeus resins showed more significant changes after soaking in red wine for 12 weeks, and its water absorption and solubility values were also greater than those of the other three types of resins. The color changes of New Century, Nissin and BASIS-HI soaked in the four solutions were relatively stable. The information obtained here will help optimize maintenance of dentures and also inform choice of denture materials.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Mohammed M. Gad ◽  
Reem Abualsaud ◽  
Shaimaa M. Fouda ◽  
Ahmed Rahoma ◽  
Ahmad M. Al-Thobity ◽  
...  

Statement of Problem. Novel polymethyl methacrylate (PMMA) containing zirconium dioxide nanoparticles (nano-ZrO2) was suggested as a denture base material but there is a lack of information regarding denture cleanser effects. Objectives. This study aimed to evaluate denture cleanser effects on color stability, surface roughness, and hardness of PMMA denture base resin reinforced with nano-ZrO2. Materials and Methods. A total of 420 specimens were fabricated of unreinforced and nano-ZrO2 reinforced acrylic resin at 2.5% and 5%, resulting in 3 main groups. These groups were further subdivided (n = 10) according to immersion solution (distilled water, Corega, sodium hypochlorite, and Renew) and immersion duration. Surface roughness, hardness, and color were measured at baseline (2 days-T0) in distilled water and then after 180 and 365 days of immersion (T1 & T2) in water or denture cleansing solutions. Data was collected and analyzed using two-way ANOVA followed by Bonferroni post hoc test (α = 0.05). Results. Surface roughness increased significantly after denture cleanser immersion of unmodified and nano-ZrO2-modified PMMA materials while hardness decreased ( P < 0.001 ). The denture cleansers significantly affected the color of both PMMA denture bases ( P < 0.001 ). The immersion time in denture cleansers significantly affected all tested properties ( P < 0.001 ). Within denture cleansers, NaOCl showed the highest adverse effects ( P < 0.05 ) while Renew showed the least adverse effects. Conclusion. Denture cleansers can significantly result in color change and alter the surface roughness and hardness of denture base resin even with ZrO2 nanoparticles addition. Therefore, they should be carefully used.


Author(s):  
Kubra Degirmenci ◽  
Mustafa Hayati Atala ◽  
Canan Sabak

Avoiding biofilm formation on dentures is associated with maintaining the surface properties of acrylic-based dentures. The aim of the study is to investigate the effects of two different cleaning agents (Corega and Klorhex 0.2% chlorhexidine gluconate) on surface roughness of the denture regarding efficacy of curing procedures. A total of sixty disc-shaped specimens were prepared with two different methods as long and short curing processes. The specimens were divided into subgroups according to the immersion solutions (distilled water, Corega tablet group and Klorhex 0.2% chlorhexidine gluconate group) (n=10). The samples were kept in a solution for 8 hours per day during a month. The average Ra1 (before exposure to the cleanser agent) and Ra2 (after exposure to the cleanser agent) of each sample was measured. A two-way ANOVA and post hoc Tukey test was used for statistical analysis. The solutions significantly increased the Ra values in both acrylic groups (p<0.001). While the effect of the distilled water group was significantly lower than Corega and Klorhex in the long-term curing group (p<0.05), no significant difference was found in the short-term curing group (p>0.05). The long-term curing time is highly effective in decreasing the surface roughness of the acrylic base material.


2018 ◽  
Vol 20 (3) ◽  
pp. 167
Author(s):  
Ruchele Dias Nogueira ◽  
Rosa Maria Pereira Moisés Barbosa Andrade ◽  
Ailla Carla Rocha Acosta Lancellotti ◽  
Regina Guenka Palma-Dibb ◽  
Vinícius Rangel Geraldo-Martins

ResumoA resina composta é o material restaurador mais utilizado atualmente. Apesar de seu sucesso clínico, o material está sujeito a alterações em suas propriedades físicas, quando exposto ao meio bucal. O objetivo foi avaliar a influência da degradação química na estabilidade de cor e na rugosidade superficial de resinas micro-híbrida e nanoparticulada. Foram confeccionados 40 discos (6,0mm x 2,0mm) da resina composta micro-híbrida (Z250XT) e 40 da resina nanoparticulada (Z350XT). Após a análise da cor inicial e da rugosidade inicial, 10 discos de cada resina foram imersos em saliva artificial (Controle, pH=6,4), suco de laranja (pH= 3,4), refrigerante de limão (pH=2,9) e vinho tinto (pH=3,1), por 4 horas por dia (37ºC) durante 30 dias. Após, foram realizadas as leituras finais de cor e rugosidade. Os dados obtidos para a estabilidade de cor foram analisados pelo Teste de Kruskal-Wallis, seguido pelo Teste de Dunn (α=5%). Para a análise da rugosidade foi utilizado o Teste t para amostras pareadas (α=5%). O manchamento provocado pela saliva artificial, suco de laranja e refrigerante foi similar, mas foi estatisticamente diferente do manchamento produzido pelo vinho, em ambas as resinas testadas. O vinho produziu o mesmo grau de manchamento nas resinas micro-híbrida e nanoparticulada. Foi observado que o suco de laranja, o refrigerante e o vinho promoveram aumento da rugosidade superficial dos discos de resina. Diante disso, concluiu-se que o vinho alterou a cor de resinas compostas micro-híbrida e nanoparticulada, e que a rugosidade superficial dos discos de resina foi alterada por todas as bebidas utilizadas.Palavras chave: Resinas Compostas. Corantes. Cor.Abstract Composite resin is the most used restorative material. Despite its clinical success, it is susceptible to changes in its physical properties when exposed to the oral environment. The aim was to evaluate the influence of acidic beverages on the color stability and on the surface roughness of the nanofilled and micro hybrid composite. Forty discs (6.0mm x 2.0mm) of the micro hybrid composite (Z250XT) and 40 of the nanofilled composite (Z350XT) were manufactured. After the measurement of the initial color and the initial roughness, 10 discs of each composite were individually immersed in artificial saliva (control, pH = 6.4), orange juice (pH=3.4), lime soda (pH = 2.9) and red wine (pH = 3.1) during 4 hours per day at 37°C for 30 days. At the end of the experiment, the final analysis of color and surface roughness were performed. The data obtained for the color stability were analyzed by Kruskal-Wallis and Dunn’s test (α= 5%). For the analysis of the surface roughness, the t test for related samples was used (α= 5%). The color changes promoted by artificial saliva, orange juice and soda were similar, but they were statistically different from staining produced by wine, in both tested composites. Wine produced the same degree of staining in both composites. Orange juice, soda and red wine increased the surface roughness of the composite discs. It was concluded that red wine significantly changes the color of micro hybrid and nanofilled composites. Furthermore, all beverages increased the surface roughness of the composites tested in the study herein.Keywords: Composite Resins. Coloring Agents. Color.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Shorouq Khalid Hamid ◽  
Lujain Ali Alghamdi ◽  
Faris A. Alshahrani ◽  
Soban Q. Khan ◽  
Asif Matin ◽  
...  

The antifungal effect of zirconium dioxide nanoparticles (ZrO2NPs) incorporated into denture base material has been inadequately investigated; additionally, to the authors’ knowledge, no studies have assessed the influence of artificial aging on the antifungal activity of these particles. Methodology. Heat-polymerized acrylic resin disks were fabricated and divided into four groups (0%, 1%, 2.5%, and 5% ZrO2NPs by weight). Antifungal activity was assessed using the direct culture and disk diffusion methods. Surface roughness and contact angles were measured using a profilometer and a goniometer, respectively. The artificial aging procedure was performed by repeating all tests at 7, 14, and 30 days following 2 rounds of thermocycling. Data were analyzed using ANOVA and Tukey’s post-hoc test ( p < 0.05 ). Results. The addition of ZrO2NPs significantly decreased the adhesion of Candida albicans with and without artificial aging procedures ( p < 0.001 ), while the disk diffusion methods did not reveal inhibition zones. ZrO2NP-modified specimens displayed significantly higher surface roughness compared to specimens in the control group ( p < 0.05 ) and showed the same behaviors with artificial aging procedures. The contact angle was significantly decreased in all modified groups in comparison to the control group ( p < 0.05 ). Conclusion. The addition of ZrO2NPs to polymethylmethacrylate denture base material reduced the adhesion of Candida albicans with a long-term antifungal effect. With the addition of ZrO2NPs, contact angles were decreased and surface roughness was increased; 1% was the most appropriate concentration. Clinical significance. The addition of ZrO2NPs to denture base material confers a long-term antifungal effect and could be used as a possible method for preventing and treating denture stomatitis.


2020 ◽  
Vol 1 ◽  
Author(s):  
Geyse Maria dos Santos Muniz Mota ◽  
Matheus Kury ◽  
Cecília Pereira da Silva Braga Tenório ◽  
Flávia Lucisano Botelho do Amaral ◽  
Cecília Pedroso Turssi ◽  
...  

This study evaluated the surface roughness and color alteration of an aged nanofilled composite exposed to different staining solutions and bleaching agents. Ninety nanofilled composite (Filtek Z350XT, 3M/Oral Care) specimens were submitted to 5,000 thermal cycles and immersed in (n = 30): red wine, coffee, and artificial saliva at 37°C for 48 h. Groups were subdivided according to the bleaching protocol (n = 10) with 20% carbamide peroxide, 38% hydrogen peroxide, or without bleaching - control. Mean surface roughness values (Ra - μm) and color parameters (L*, a*, b*) were measured at baseline (T0), after thermal cycling aging and staining (TS), and after bleaching (TB). Color (ΔE00) and whiteness index (ΔWID) changes were determined after aging and staining (Ts-T0) and after bleaching (TB-TS). The adopted perceptibility and acceptability thresholds of the nanofilled composite were 0.81 and 1.71 ΔE00 units and 0.61 and 2.90 ΔWID units, respectively. Ra was analyzed using mixed models for repeated measurements and L* by the Tukey-Kramer test. The a* and b* values were evaluated by generalized linear models for repeated measures. ΔE00 was tested using two-way ANOVA and Tukey tests, and ΔWID by Kruskal-Wallis and Dunn tests (α = 5%). Ra of all groups decreased after aging and staining (TS, p &lt; 0.05), but increased after bleaching only for groups stained with red wine (TB). Aging and staining decreased the luminosity of the composites, but L* increased after bleaching (p &lt; 0.05). Aging and staining increased a* and b* values, but after bleaching, b* values decreased (p &lt; 0.05). After bleaching, ΔE00 and ΔWID were greater in stained groups at both time intervals, regardless of the bleaching protocol. Stained resin composites exhibited perceptible but unacceptable color (ΔE00 &gt; 1.71) and whiteness (ΔWID &gt; 2.90) changes, regardless of the bleaching treatment performed. Therefore, red wine affected the surface roughness of the aged nanofilled resin submitted to bleaching. Bleaching was unable to reverse the color changes promoted by red wine and coffee on the aged nanofilled composite.


Sign in / Sign up

Export Citation Format

Share Document