The Effect of Bleach Liquid and Household Cleaner on Surface Hardness and Roughness of Acrylic Base of Orthodontic Appliances

Author(s):  
Saeed Noorollahian ◽  
Farinaz Shirban ◽  
Vahid Mojiri

Introduction: The daily use of orthodontic removable plates can interfere with the self-cleansing function of the mouth. Although various techniques have been proposed for cleaning removable orthodontic appliances, there is no consensus on the use of a safe method that preserves the physical properties of the appliance. This study aimed to investigate the effect of using hydrochloric acid (10%, for removal of mineral deposits) and sodium hypochlorite (5.25%, to remove organic matter and discolorations) on surface hardness and roughness of self-cure orthodontic acrylic resins. Materials & Methods: This cross-sectional laboratory study was conducted in the fall of 2017 at Isfahan University of Medical science and Isfahan University of Technology. In this study two orthodontic acrylic resins (Orthocryl® and Acropars®) were used. Eighty samples (12×10×3 mm) from each one were fabricated and divided into four groups (n = 20). Group 1: 15 minutes immersion in household cleaner liquid (Hydrochloric acid, 10%) followed by15 minutes immersion in household bleach liquid (Sodium Hypochlorite, 5.25%). In group 2, immersions were repeated just like group two times and in group 3, were done three times. Group 4 was as control and had no immersion. The surface hardness and roughness of samples were measured. Data were analyzed with Two Way ANOVA and the significance level was set at 0.05. Results: The number of immersion procedures did not significantly affect the surface hardness (p value = 0.958) and surface roughness (p value = 0.657) in the different study groups. There was no significant difference in the surface hardness between the two acrylic resin brands (p value = 0.077); however, Acropars acrylic resin samples exhibited significantly higher surface roughness compared to the Orthocryl acrylic resin samples(p value < 0.001). Conclusion: 15 minutes of immersion in 10% HCl, followed by 15 minutes of immersion in 5.25% NaOCl and repetition of the procedure three times did not significantly affect the surface hardness and roughness of self-cured acrylic resins.

Author(s):  
Tahir Karaman ◽  
Faruk Oztekin ◽  
Samet Tekin

Introduction: Pathogens, such as cytomegalovirus, hepatitis B virus, hepatitis C virus, herpes simplex virus types 1 and 2, and human immunodeficiency virus are transmitted, threatening the health of dental laboratory workers, especially as a result of saliva and blood contact of patients. To prevent cross-infection, impression materials should be disinfected at the end of the impression process in the mouth. Aim: To study the effect of application time of sodium hypochlorite and quaternary ammonium-based disinfectant solution on the surface roughness of an elastomeric impression material. Materials and Methods: In this in-vitro study done during March 2020, 10 disc-shaped samples were used in each group, with a total of 110 samples obtained from a light body elastomeric impression material with dimensions of 15×3 mm. The samples were kept in a sodium hypochlorite solution (Wizard; Rehber Kimya, Istanbul, Turkey) at concentrations of 1% and 5% for 1, 5, 10, and 30 minutes and in a quaternary ammonium-based disinfectant (Zeta 7 Solution, Zhermack SpA, Italy) for 10 and 30 minutes. Surface roughness measurements were taken with a profilometer device. The data obtained were statistically analysed by Kolmogorov-Smirnov test and Wilcoxon signed rank test for dependent/paired groups for the continuous data. The significance level was set to α=0.05. Results: A statistically significant difference was found between the control group and the 1% sodium hypochlorite (30 min p-value 0.037), and 5% sodium hypochlorite (30 min p-value 0.017). The statistical evaluation of the surface roughness of the samples with different concentrations of sodium hypochlorite and the same times was done and found statistically significant at 30 mins, p-value 0.021. Conclusion: The prolonged application of the sodium hypochlorite disinfectant at 1% and 5% concentrations caused a significant increase in the light body elastomeric impression material’s surface roughness


2017 ◽  
Vol 65 (4) ◽  
pp. 303-307
Author(s):  
Gabriel Lúcio Calazans DUARTE ◽  
Angélica Kercya Pereira de MENDONÇA ◽  
Ana Roberta Assunção de FREITAS ◽  
Antônio Ricardo Calazans DUARTE ◽  
Julita de Campos Pipolo HOLANDA

ABSTRACT Objective : To evaluate the surface roughness of two makes of autopolymerized acrylic resin (Classic Dencor® and Duralay®) with two different methods of finishing and polishing (conventional and using the Dhpro® finishing & polishing kit). Methods : A total of 20 specimens (10 of each make) was obtained using Zetalabor®--Zhermak condensation silicone molds. After polymerization, 20 blocks of resin were divided in two and subjected to two types of finishing and polishing, one at each end. The types of finishing and polishing were as follows: conventional (lathe) and using the Dhpro® finishing & polishing kit. Once finished and polished, the specimens were subjected to surface roughness testing using a roughness meter and were analyzed via the Student’s t-test. Results : There is a statistically significant difference between the forms of polishing, unrelated to the brand of acrylic resin. Conventional polishing achieved a level of 0.12 µm for both resins and the DhPro® polishing presented roughness a little above 0.2 µm. Conclusion : Conventional polishing is superior to the DhPro® kit, as it achieves lower levels of roughness. There is no significant difference between the acrylic resins in terms of surface roughness after the finishing and polishing processes.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
A. Z. Yildirim-Bicer ◽  
I. Peker ◽  
G. Akca ◽  
I. Celik

Objective. The aim of this study was to evaluate alternative methods for the disinfection of denture-based materials.Material and Methods. Two different denture-based materials were included in the study. Before microbial test, the surface roughness of the acrylic resins was evaluated. Then, the specimens were divided into 8 experimental groups(n=10), according to microorganism considered and disinfection methods used. The specimens were contaminated in vitro by standardized suspensions ofCandida albicansATCC#90028 andCandida albicansoral isolate. The following test agents were tested: sodium hypochlorite (NaOCl 1%), microwave (MW) energy, ultraviolet (UV) light, mouthwash containing propolis (MCP), Corega Tabs, 50% and 100% white vinegar. After the disinfection procedure, the number of remaining microbial cells was evaluated in CFU/mL. Kruskal-Wallis, ANOVA, and Dunn’s test were used for multiple comparisons. Mann WhitneyUtest was used to compare the surface roughness.Results. Statistically significant difference(P<0.05)was found between autopolymerised and heat-cured acrylic resins. The autopolymerised acrylic resin surfaces were rougher than surfaces of heat-cured acrylic resin. The most effective disinfection method was 100% white vinegar for tested microorganisms and both acrylic resins.Conclusion. This study showed that white vinegar 100% was the most effective method for tested microorganisms. This agent is cost-effective and easy to access and thus may be appropriate for household use.


Author(s):  
Syafrinani Syafrinani ◽  
Yudi Setiawan

Denture base widely were made from heat polymerized acrylic resin. Either one of physical properties on this material must be concern is surface roughness, rough surface could interfere patient’s comfort, and microbial colonization. Therefore polishing procedure were needed, polishing material that mostly used on acrylic resin was pumice, there is another alternative material i.e eggshell and toothpaste because had abrasive ability. The aim of this research is to determine the difference surface roughness of heat polymerized acrylic denture base resin used pumice, eggshell and toothpaste as polishing materials. The design research in this study is laboratory experimental with rectangle sample with size 50 x 20 x 3 ±1 mm. There are 30 samples for 3 groups. The result of this research shows a significant difference between pumice group and eggshell group with p value = 0,0001 (p < 0,05), pumice and toothpaste with p value = 0,0001 (p < 0,05), egghsell and toothpaste with p value = 0,032 (p < 0,05). Polishing that used an alternative material from eggshell and toothpaste produce lower surface roughness score rather than pumice.


2021 ◽  
Vol 17 (1) ◽  
pp. 22-26
Author(s):  
Kadek Ayu Wirayuni ◽  
◽  
I Made Hendri Dwi Saputra ◽  

Introduction: The denture base is the part of the removable denture that is supported by good adaptation to the underlying oral tissue. Most of the denture bases are made of acrylic or polymethyl methacrylate resin, better known as PMMA. However, the acrylic resin also has disadvantages such as easily broken and absorbs liquids both water and chemicals. The chemical absorption like alcohol, ethanol, and some drinks that contain acidic materials will chemically be induced with acrylic resin and settle in the pores of the acrylic resin. The chemical damage or defect creates roughness on the surface of the acrylic resin which can cause cracking or crazing and a decrease in surface strength and hardness. Materials and Methods: The method used in this research was a laboratory experimental design with a post-test-only control group using 12 samples consisting of 2 different types of samples by measuring the surface roughness of the acrylic resin after immersing the sample with a predetermined time. Results and Discussions: One-way ANOVA test results showed a significant difference in surface roughness after the samples immersion with a value of p = 0.006 (p <0.05). Conclusions: Based on this research, can be concluded that there is an increase in the surface roughness of the heated polymerized acrylic resin for 3 hours and 4 hours of immersion. The longer the heated polymerized acrylic resin is soaked in arak hence the level of surface roughness increases.


2013 ◽  
Vol 18 (6) ◽  
pp. 26-30 ◽  
Author(s):  
Glaucio Serra ◽  
Liliane Siqueira de Morais ◽  
Carlos Nelson Elias

INTRODUCTION: The finishing and polishing phases are essential to improve smoothness and shining on the surface of acrylic resins used to make removable orthodontic appliances. A good surface finishing reduces roughness, which facilitates hygiene, prevents staining and provides greater comfort to the patients. OBJECTIVE: The aim of this paper was to analyze the changes on surface morphology of acrylic resins during finishing and polishing phases. METHODS: Thirty discs (10 mm in diameter and 5 mm in length) were made with acrylic resin and randomly divided into ten groups. The control group did not receive any treatment while the other groups received gradual finishing and polishing. The last group received the entire finishing and polishing procedures. Surface morphology was qualitatively analyzed through scanning electron microscopy and quantitatively analyzed through a laser profilometer test. RESULTS: The acrylic resin surfaces without treatment showed bubbles which were not observed in the subsequent phases. Wearing out with multilaminated burs, finishing with wood sandpaper and finishing with water sandpaper resulted in surfaces with decreasing irregularities. The surfaces that were polished with pumice and with low abrasive liquids showed high superficial smoothness. CONCLUSION: Highly smooth acrylic resin surfaces can be obtained after mechanical finishing and polishing performed with multilaminated burs, wood sandpaper, water sandpaper, pumice and low abrasive liquids.


2017 ◽  
Vol 11 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Saja Ali Muhsin

Background: Although bonding to denture teeth after surface treatment with chemical agents is desirable, there is little information on the use of Visible Light Cure composite resin (VLC) as bonding denture materials. Objectives: To determine the effect of various surface treatments on shear bond strength between Visible Light Cure composite resin and the acrylic denture teeth interface. Methods: Forty cylindrical sticks of acrylic resin with denture teeth mounted atop were prepared. Various treatments were implemented upon the acrylic resin teeth surfaces. The samples were divided into four groups (n = 10). Light-cured composite resin (LC) was applied over all treated and untreated surfaces of tested groups. The shear bond was tested using a universal tensile testing apparatus with the knife-edge of a 0.8mm shear tester. Data were statistically analyzed using one-way ANOVA performed at a confidence level of 95% and significant P-value of (P ≤ 0.05). Results: Analysis of variance (ANOVA) showed statistically significant difference (P < 0.05) between treated and untreated teeth surfaces. The treated surfaces exhibited various levels of bond strength depending on the type of treatment. Conclusion: Application of VLC bonding agent with prior treatment of methylmethacrylate (MMA) on the acrylic resin denture teeth resulted in maximum bond strength with composite resin.


2019 ◽  
Vol S (1) ◽  
pp. 7-10
Author(s):  
Ahmed Asim Saeed Al-Ali ◽  
◽  
Ammar k. Al-Noori ◽  
Amer A. Taqa ◽  
◽  
...  

Objectives: Compare tensile and transverse strength of new copolymers for denture base. Materials and methods: The specimens were prepared from heat cured acrylic resin with three types of additives: Acryester B, Ethoxycarbonylethylene, and Propenoic acid at a percentage of 5% and 10%. The tensile and transverse strains were tested, recorded and compared. Results: The analysis of variance display statistically significant difference. The p-value was 0.001 for each of tensile and transverse strain tests. Conclusions: The tensile strength of the novel copolymers increased. The transverse strength of some of the novel copolymers increased.


2013 ◽  
Vol 24 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Helena de Freitas Oliveira Paranhos ◽  
Amanda Peracini ◽  
Marina Xavier Pisani ◽  
Viviane de Cássia Oliveira ◽  
Raphael Freitas de Souza ◽  
...  

This study evaluated color stability, surface roughness and flexural strength of acrylic resin specimens after immersion in alkaline peroxide and alkaline hypochlorite, simulating a period of one and a half year of use of overnight immersion. Sixty disc-shaped (16X4 mm) and 80 rectangular specimens (65X10X3.3 mm) were prepared from heat-polymerized acrylic resin (Lucitone 550) and distributed into 4 groups (n=20): C1: without immersion, C2: 8 h immersion in distilled water; AP: 8 h immersion in alkaline peroxide effervescent tablet; SH: 8 h immersion in 0.5% NaOCl solution. Properties were evaluated at baseline and after the immersion. Color data were also calculated according the National Bureau of Standards (NBS). Results were analyzed statistically by ANOVA and Tukey's HSD test (α=0.05). AP (2.34 ± 0.41) caused color alteration significantly higher than C2 (0.39 ± 0.30) and SH (1.73 ± 0.52). The mean ΔE values were classified as indicial for C2 (0.36 ± 0.29) and noticeable for AP (2.12 ± 0.39) and SH (1.59 ± 0.48). SH (0.0195 ± 0.0150) caused significantly higher ΔRa (p=0.000) than the C2 (0.0005 ± 0.0115) and PA (0.0005 ± 0.0157) groups. There was no statistically significant difference (p=0.063) among the solutions for flexural strength (C1: 105.43 ± 14.93, C2: 100.30 ± 12.43, PA: 97.61 ± 11.09, SH: 95.23 ± 10.18). In conclusion, overnight immersion in denture cleansing solutions simulating a year and a half of use did not alter the flexural strength of acrylic resin but caused noticeable color alterations, higher for alkaline peroxide. The 0.5% NaOCl solution caused increase in surface roughness.


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