scholarly journals Effect of repeated cycles of chemical disinfection in microhardness of acrylic resins of complete denture base

2017 ◽  
Vol 65 (3) ◽  
pp. 196-201
Author(s):  
Elisa das Graças MARTINS ◽  
Rafael Tobias MORETTI NETO
Keyword(s):  
Sodium Hypochlorite ◽  
Knoop Hardness ◽  
Sodium Hypochlorite Solution ◽  
Chlorhexidine Digluconate ◽  
Water Control ◽  
Denture Base ◽  
Acrylic Resins ◽  
Hardness Tests ◽  
Before And After ◽  
Edentulous Patients

ABSTRACT Objective: To evaluate the microhardness of specimens of acrylic resins VipiCril® (thermally polymerized resin) and Bosworth New Truliner® (self-polymerized resin), before and after immersion in solutions of 0.12% chlorhexidine digluconate, 1% sodium hypochlorite, Corega Tabs® and water (control), testing the null hypothesis that the mouthwashes and chemicals used to disinfect complete dentures do not interfere with the superficial microhardness, and can therefore be used as adjuncts to oral hygiene of edentulous patients. Methods: Sixty specimens of resin VipiCril®(thermally polymerized resin) and 60 specimens of resin Bosworth New Truliner® (self-polymerized resin) measuring 16 mm of diameter and 6 mm of height were prepared, which were randomly divided into four groups of 15 specimens each, undergoing Knoop hardness tests (KHN) both before and after cycles of immersion in solutions of 0.12% chlorhexidine digluconate, 1% sodium hypochlorite, Corega Tabs® and water (control). Results: The specimens of resins VipiCril and Bosworth immersed in solutions of 0.12% chlorhexidine, Corega Tabs® and water showed decreased microhardness. Conclusion: The 1% sodium hypochlorite solution caused least damage to the denture structure, not leading to decrease of the superficial microhardness.

scholarly journals Effect of repeated disinfections by microwave energy on the physical and mechanical properties of denture base acrylic resins

2009 ◽  
Vol 20 (2) ◽  
pp. 132-137 ◽  
Author(s):  
Rafael Leonardo Xediek Consani ◽  
Douglas Duenhas de Azevedo ◽  
Marcelo Ferraz Mesquita ◽  
Wilson Batista Mendes ◽  
Paulo César Saquy
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
Knoop Hardness ◽  
Microwave Energy ◽  
Bending Test ◽  
Denture Base ◽  
Acrylic Resins ◽  
The Impact

The present study evaluated the effect of repeated simulated microwave disinfection on physical and mechanical properties of Clássico, Onda-Cryl and QC-20 denture base acrylic resins. Aluminum patterns were included in metallic or plastic flasks with dental stone following the traditional packing method. The powder/liquid mixing ratio was established according to the manufacturer's instructions. After water-bath polymerization at 74ºC for 9 h, boiling water for 20 min or microwave energy at 900 W for 10 min, the specimens were deflasked after flask cooling and finished. Each specimen was immersed in 150 mL of distilled water and underwent 5 disinfection cycles in a microwave oven set at 650 W for 3 min. Non-disinfected and disinfected specimens were subjected to the following tets: Knoop hardness test was performed with 25 g load for 10 s, impact strength test was done using the Charpy system with 40 kpcm, and 3-point bending test (flexural strength) was performed at a crosshead speed of 0.5 mm/min until fracture. Data were analyzed statistically by ANOVA and Tukey's test (α= 0.05%). Repeated simulated microwave disinfections decreased the Knoop hardness of Clássico and Onda-Cryl resins and had no effect on the impact strength of QC-20. The flexural strength was similar for all tested resins.

scholarly journals MANUFACTURING OF FULL REMOVABLE LAMINAR DENTURES USING DIFFERENT GROUPS OF MATERIALS FOR DENTURE BASES AND THEIR COMPARATIVE CHARACTERISTICS

2020 ◽  
Vol 20 (3) ◽  
pp. 55-59
Author(s):  
V.S. Kuz ◽  
E.B. Tumakova ◽  
G.M. Kuz ◽  
A.I. Teslenko ◽  
L.B. Eris
Keyword(s):  
Base Material ◽  
Clinical Findings ◽  
Denture Base ◽  
Acrylic Plastic ◽  
Base Materials ◽  
Acrylic Resins ◽  
Functional Quality ◽  
Removable Denture ◽  
Edentulous Patients

Restoration of complete maxillary or mandibular adentia, despite the advances of dentistry nowadays, has always been and is still remaining one of the most challenging among the clinical issues of orthopedic dentistry. The effectiveness of a high-quality complete removable denture is largely predetermined by the properties of the denture base material. However, long experience in manufacturing the dentures has revealed a number of their disadvantages. The development of new denture base materials and their studies have been being carried out for many years. The aim of this work was to investigate the effectiveness of thermoplastic base material "Vertex ThermoSense" (Netherlands) and fluorine-containing acrylic plastic "Ftoraks" (Ukraine) used in manufacturing the dentures for edentulous patients who previously worn full removable dentures made of acrylic plastic over the past 3- 5 years. We examined and treated 43 patients with complete anodontia who went to the orthodontic clinic to order a new denture. We used fluorine-containing acrylic co-polymers "Ftorax" (Ukraine) and polyamide (nylon) "Vertex ThermoSense" (Netherlands), recommended by manufacturers for making removable dentures. We assessed the level subjective satisfaction with new dentures in different follow-up time intervals, checked the restoration of the chewing function in the patients using electromyographic techniques. Clinical findings obtained supported the superiority of Vertex ThermoSense thermoplastic material over fluorine-containing acrylic resins in terms of high functional quality and strength that facilitate the durability of these complete dentures. In addition, the denture base made of "Vertex ThermoSense" does not contain residual monomer, thereby preventing the occurrence of allergic reactions. The results of our work allow us to strongly recommend the material "Vertex ThermoSense" to implement into prosthodontic practice for manufacturing complete removable dentures.

scholarly journals Alkaline Peroxides Versus Sodium Hypochlorite for Removing Denture Biofilm: a Crossover Randomized Trial

2016 ◽  
Vol 27 (6) ◽  
pp. 700-704 ◽  
Author(s):  
Amanda Peracini ◽  
Rômulo Rocha Regis ◽  
Raphael Freitas de Souza ◽  
Valéria Oliveira Pagnano ◽  
Cláudia Helena Lovato da Silva ◽  
...  
Keyword(s):  
Sodium Hypochlorite ◽  
Estimating Equation ◽  
Total Surface Area ◽  
Neutral Red ◽  
Generalized Estimating Equation ◽  
Sodium Hypochlorite Solution ◽  
Alkaline Peroxide ◽  
Biofilm Removal ◽  
Edentulous Patients ◽  
Control Water

Abstract This study evaluated the efficacy of cleanser solutions on denture biofilm removal by a crossover randomized clinical trial. Thirty two edentulous patients were instructed to brush their dentures (specific brush and liquid soap) three times a day (after breakfast, lunch and dinner) and to soak them (≥ 8 h) in: (C) control -water; (AP): alkaline peroxide; or (SH) 0.5% sodium hypochlorite. Each solution was used for 21 days (three cycles of 7 days). At the end of each cycle, the inner surfaces of maxillary dentures were disclosed (1% neutral red) and photographed (HX1 - Sony). Areas (total and stained biofilm) were measured (Image Tool software) and the percentage of biofilm calculated as the ratio between the area of the biofilm multiplied by 100 and total surface area of the internal base of the denture. Data were compared by means of generalized estimating equation (α=5%) and multiple comparisons (Bonferroni; α=1.67%). Immersion in SH reduced biofilm (%) (8.3 ± 13.3B) compared to C (18.2 ± 14.9A) and AP (18.2 ± 16.6A). The 0.5% sodium hypochlorite solution was the most efficacious for biofilm removal. Alkaline peroxides may not lead to further biofilm removal in patients with adequate denture maintenance habits.

scholarly journals Effects of repeated long-term sodium hypochlorite disinfection treatment on surface hardness and roughness of self-polymerizing reline acrylic resins

2014 ◽  
Vol 2 (1) ◽  
pp. 91
Author(s):  
Luciana Rezende Pinto ◽  
Dayane Rubim ◽  
Paulo Maurício Batista Silva ◽  
Vinícius Carvalho Porto
Keyword(s):  
Sodium Hypochlorite ◽  
Surface Hardness ◽  
Knoop Hardness ◽  
Control Group ◽  
Predisposing Factor ◽  
Denture Stomatitis ◽  
Tukey Test ◽  
Acrylic Resins ◽  
Chemical Disinfectant

Denture stomatitis is the most common alteration on the palate of denture wearers and deficient denture hygiene is an important predisposing factor, because it facilitates both the presence of Candida albicans and bacteria in saliva and their colonization on the oral mucosa and denture surfaces. Sodium hypochlorite is an efficient chemical disinfectant to eliminate denture biofilm, but the effect of long-term disinfection on reline acrylic resins was not studied. Purpose: This study investigated the hardness and roughness of three self-polymerizing reline resins after repeated long-term sodium hypochlorite disinfections. Material and methods: Forty round specimens (30 x 6mm) were made from each material: Jet, Kooliner and Tokuyama Rebase II Fast, and divided in 4 groups (n=10). The control group was stored in water and the others were disinfected with 1%, 2%, 5.25% sodium hypochlorite, respectively. The specimens were tested for knoop hardness (KHN) and roughness (Ra) before disinfection and after 30, 90 and 180 disinfection cycles. Data were analyzed by analysis of variance followed by the Tukey test at 5%. Results: The hardness of Jet resin varied from 18.74 ± 0.47 to 13.75 ± 0.95 KHN, Kooliner varied from 14.09 ± 1.63 to 7.52 ± 0.88 KHN, and Tokuyama Rebase II Fast from 12.57 ± 0.94 to 8.28 ± 0.39 KHN. Statistically significant decrease in hardness of the three reline acrylic resins was observed early after the first 30 disinfection cycles. Conclusion: The hardness of the tested materials decreased after immersion in water and after repeated long-term chemical disinfections

scholarly journals Comparison of physical and mechanical properties of microwave-polymerized acrylic resin after disinfection in sodium hypochlorite solutions

2009 ◽  
Vol 20 (4) ◽  
pp. 331-335 ◽  
Author(s):  
Helena de Freitas Oliveira Paranhos ◽  
Letícia Resende Davi ◽  
Amanda Peracini ◽  
Rafael Bellini Soares ◽  
Cláudia Helena da Silva Lovato ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Flexural Strength ◽  
Sodium Hypochlorite ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Color Stability ◽  
Acrylic Resin ◽  
Bending Test ◽  
Water Control ◽  
Before And After

This study evaluated the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin after immersion in sodium hypochlorite (NaOCl), simulating 20 min of disinfection daily during 180 days. Forty disk-shaped (15 x 4 mm) and 40 rectangular (65 x 10 x 3 mm) specimens were prepared with a microwave-polymerized acrylic resin (Onda-Cryl). Specimens were immersed in either 0.5% NaOCl, 1% NaOCl, Clorox/Calgon and distilled water (control). Color measurements were determined by a portable colorimeter. Three parallel lines, separated by 1.0 mm, were registered on each specimen before and after immersion procedures to analyze the surface roughness. The flexural strength was measured using a 3-point bending test in a universal testing machine with a 50 kgf load cell and a crosshead speed of 1 mm/min. Data were analyzed statistically by ANOVA and Tukey's test (?=0.05). There was no statistically significant differences (p>0.05) among the solutions for color, surface roughness and flexural strength. It may be concluded that immersion in NaOCl solutions simulating short-term daily use during 180 days did not influence the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin.

scholarly journals Effects of nystatin, fluconazole and propolis on poly(methyl methacrylate) resin surface

2008 ◽  
Vol 19 (3) ◽  
pp. 190-196 ◽  
Author(s):  
Wander José da Silva ◽  
Rodrigo Nunes Rached ◽  
Pedro Luis Rosalen ◽  
Altair Antoninha Del Bel Cury
Keyword(s):  
Free Energy ◽  
Methyl Methacrylate ◽  
Antifungal Agents ◽  
Knoop Hardness ◽  
Deionized Water ◽  
Control Groups ◽  
Denture Base ◽  
Poly Methyl Methacrylate ◽  
Acrylic Resins ◽  
Pmma Surface

The prevalence of candidosis in denture wearers is as well established as its treatment with antifungal agents (AAs). However, little research has been done regarding the effects of AAs on denture base surfaces. Therefore, the aim of this study was to evaluate the effects of fluconazole (FLU), nystatin (NYS) and propolis orabase gel (PRO) on poly (methyl-methacrylate) (PMMA) surfaces. Deionized water and orabase gel without any active component were used as control groups. Conventional heat-polymerized (Clássico) and microwave-polymerized (Onda Cryl) acrylic resins were used. After polymerization, the specimens were polished and had their surfaces evaluated for roughness, free energy and Knoop hardness. Subsequently, specimens were immersed in AAs and controls for 14 days at 35±2 °C and all variables were measured again. Data were analyzed statistically by 2-way ANOVA followed by Tukey's test ( α=0.05). Roughness results showed similar behavior for both PMMA resins, with PRO reaching the highest values and differing significantly from the other AAs (p<0.05). No statistically significant differences (p>0.05) were found between the two PMMA resins or between NYS and FLU as regards surface free energy. In conclusion, PRO was able to induce changes in PMMA surface properties, such as roughness, which could be related to microbial adhesion.

scholarly journals Influence of Concentration and Agitation of Sodium Hypochlorite and Peracetic Acid Solutions on Tissue Dissolution

2015 ◽  
Vol 16 (11) ◽  
pp. 876-879 ◽  
Author(s):  
Mario Tanomaru-Filho ◽  
Juliane Maria Guerreiro-Tanomaru ◽  
Bruna Ramos Franco Silveira ◽  
Roberta Bosso Martelo
Keyword(s):  
Sodium Hypochlorite ◽  
Peracetic Acid ◽  
Sodium Hypochlorite Solution ◽  
Acid Solutions ◽  
Mass Reduction ◽  
Pulp Tissue ◽  
Hypochlorite Solution ◽  
Ultrasonic Agitation ◽  
Before And After ◽  
The Difference

ABSTRACT Aim and objective To evaluated the tissue dissolution of sodium hypochlorite (NaOCl) and peracetic acid (PA) solutions at different concentrations, with or without ultrasonic agitation. Materials and methods The following solutions were analyzed: 2.5% NaOCl, 0.5, 1 and 2% PA, 1% PA associated with 6.5% hydrogen peroxide (HP) and saline. Fragments of bovine pulp tissue with 25 ± 2g mg were immersed into test tubes containing 4 mL of the solutions for 10 minutes. In the groups with agitation, pulp tissues were submitted to 2 cycles of 1 minute of ultrasonic agitation. The specimens were weighed after the removal from the solutions. The percentage of mass loss was calculated according to the difference of mass before and after exposure to solutions. Data were submitted to ANOVA and Tukey tests (p . 0.05). Results A total of 2.5% NaOCl with or without agitation showed the higher tissue dissolution (between 64.5 and 67% of mass reduction) (p < 0.005). By comparing the PA solutions, the concentrations of 1 and 2% with or without agitation and the concentration of 0.5% with agitation showed similar dissolution activity (between 35.4 and 44% of mass reduction). The use of the ultrasonic agitation promoted an increase of the dissolution ability only for 0.5% PA. Conclusion Peracetic acid solution has pulp tissue dissolution. However, this ability is lower than 2.5% NaOCl solution. Clinical significance The sodium hypochlorite solution shows higher ability to dissolve tissue than PA. How to cite this article Tanomaru-Filho M, Silveira BRF, Martelo RB, Guerreiro-Tanomaru JM. Influence of Concentration and Agitation of Sodium Hypochlorite and Peracetic Acid Solutions on Tissue Dissolution. J Contemp Dent Pract 2015;16(11):876-879.

scholarly journals Color variation of acrylic resins immersed in pigment beverages according to the consume habits: a pilot study

2014 ◽  
Vol 2 (3) ◽  
pp. 199
Author(s):  
Renato Fabrício de Andrade Waldemarin ◽  
Lucas Brum Cleff ◽  
Lauren Grandi Santos ◽  
Guilherme Brião Camacho ◽  
Luciana De Rezende Pinto
Keyword(s):  
Artificial Saliva ◽  
Black Tea ◽  
Color Variation ◽  
Distilled Water ◽  
Water Control ◽  
Color Changes ◽  
Acrylic Resins ◽  
Significant Difference ◽  
Before And After ◽  
Cie Lab

AIM: evaluate the color changes in acrylic resins immersed in two pigmented beverages in different time periods, proportional to the frequency and volume of consume by the population with and without the use of artificial saliva. MATERIAL AND METHODS: Thirty thermo-polymerizable resin disks were confectioned with 3.0 +- 0.1 mm thickness, initially immersed in distilled water for 24 hours and randomly divided into 2 groups (n=15): GC – with artificial saliva and GS – without artificial saliva. They were, then, subdivided into 3 subgroups (n=5): G1 – distilled water (control); G2 – red wine; G3 – black tea. These groups were daily immersed inside beverages for 15 days, with daily immersion frequency equal to the beverage ingestion and the period of each immersion equal to 1 minute/10 ml of beverage per capita. Between each immersion the disks were stored inside distilled water. The color of resins was measured according to the CIE-Lab scale before and after the immersion periods, and the color variation was calculated (ΔE). The values ΔL*, Δa* e Δb* were also evaluated. RESULTS: Analysis of variance was performed, and have shown significant difference (p<0.05) among G1 and the other solutions, without significant difference between G2 and G3 for ΔE, ΔL, Δa and the module Δb. There was no difference between GC and GS. CONCLUSION: It was concluded that the use of artificial saliva did not change pigmentation degree and that wine presents similar changes to the tea, considering the parameters used. 

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