Influence of Different Disinfectants on Surface Hardness of Heat-Polymerized Acrylic Resins utilized for Orthodontic Appliance

2021 ◽  
Vol 3 (1) ◽  
pp. 61-65
Author(s):  
Wael Abdul Alrazzaq Alwaeli ◽  
Mohammed Abdul Sattar Alsegar
Keyword(s):  
Chemical Interaction ◽  
Surface Hardness ◽  
Orthodontic Appliances ◽  
Distilled Water ◽  
Water Control ◽  
Mean Values ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
Dental Prostheses ◽  
Removable Dental Prostheses

Heat-polymerized resins are common substances utilized for construction of removable dental prostheses (i.e. Orthodontic appliances). Such materials should have appropriate physical properties. The use of disinfectant solutions might influence the physical characteristics of the acrylic materials.  This study was conducted to assess the influence of different disinfectants on heat polymerized resins in terms of surface hardness. Forty specimens were made from heat-polymerized acrylic resins in total. The investigation comprised 4 groups according to the disinfectants utilized and each group had ten specimens. The 1st group was immersed in distilled water (control); the 2nd group was disinfected in Efferdent; the 3rd group was disinfected in 4 % Chlorhexidine; and the 4th group was disinfected in 1% hypochlorite. All specimens were tested via a hardness tester three times and the average reading was measured for all specimens. The statistical results indicated a slight decline in the mean values of surface hardness of acrylic specimens following immersion in disinfectants. The greatest value of mean was for distilled water specimens whereas the lowest value of mean was for 4% Chlorhexidine specimens. Furthermore, no significant differences were found among all groups (P>0.05). The study concluded that the use of disinfectants solutions slightly decreases the hardness of heat polymerized resins. It is recommended to evaluate the chemical interaction between the acrylic resins and disinfectants.

scholarly journals In Vitro Evaluation of Physical and Mechanical Properties of Light-Curing Resin Cement: A Comparative Study

2020 ◽  
Vol 14 (01) ◽  
pp. 152-156
Author(s):  
Luís Felipe Espíndola-Castro ◽  
Oscar Felipe Fonseca de Brito ◽  
Larissa Gabrielle Assis Araújo ◽  
Izabella Luiza Aragão Santos ◽  
Gabriela Queiroz De Melo Monteiro
Keyword(s):  
Color Change ◽  
Surface Hardness ◽  
Color Stability ◽  
Resin Cement ◽  
The Other ◽  
Distilled Water ◽  
Water Control ◽  
Mean Values ◽  
Significance Level

Abstract Objective The aim of study was to evaluate in vitro the surface hardness, sorption, solubility, and color stability of three light-cured resin cements, namely RelyX Veneer (RLX), Variolink Veneer (VLK), and All Cem Veneer (ACV). Materials and Methods Cylindrical samples (15 × 1 mm) were made for each group using a metallic mold (n = 10). Vickers microhardness test was performed, and average hardness was calculated from three indentations (300 gf/15s) per sample. The sorption and solubility of the materials were evaluated according to ISO 4049:2009 based on three samples weighing: initial (m 1), after immersion in distilled water for 7 days (m 2), and final (after removal of all moisture [m 3]). The color change was observed using a digital spectrophotometer, at three different time points, baseline, 1 day, and 1 week of immersion in coffee and distilled water (control). Statistical Analysis Shapiro–Wilk test was used to analyze the normality of the data, and groups were compared using Kruskal–Wallis and Mann–Whitney tests. A significance level of 5% was used. Results RLX showed the highest microhardness mean values (36.96 VHN), but higher sorption (23.2 µg/mm3) and solubility (2.40 µg/mm3), with statistically significant differences with the other groups. For color stability, higher ∆E was observed for the samples immersed in coffee (p = 0.009). The VLK resin cement presented statistically significant differences from the other groups, with higher color changes in coffee at 1 day (15.14) and after 1 week (23.65). Conclusion RLX resin cement showed better hardness results. All materials tested performed satisfactorily for sorption and solubility according to ISO 4049:2009. All materials showed high-staining values after 1 week of immersion in coffee.

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

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

2021 ◽  
Author(s):  
Saeed Noorollahian ◽  
Farinaz Shirban ◽  
Vahid Mojiri
Keyword(s):  
Surface Roughness ◽  
Hydrochloric Acid ◽  
Sodium Hypochlorite ◽  
Surface Hardness ◽  
Acrylic Resin ◽  
Liquid Sodium ◽  
P Value ◽  
Orthodontic Appliances ◽  
Acrylic Resins ◽  
Significant Difference

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.

scholarly journals PEEK Biomaterial Use for Chairside CAD/CAM Dental Restorations: Bridging the Gap to Future

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Nagy Abdulsamee
Keyword(s):  
Computer Aided Design ◽  
Chemical Properties ◽  
Pediatric Dentistry ◽  
Orthodontic Appliances ◽  
Dental Prostheses ◽  
Removable Dental Prostheses ◽  
Wide Range ◽  
Computer Aided ◽  
Cad Cam

Background: Advanced computer-aided design and computer-aided manufacturing (CAD-CAM) technology led to the introduction of an increasing number of machinable materials suitable for dental prostheses. One of these materials is polyetheretherketone (PEEK), a high performance polymer recently used in dentistry with favorable physical, mechanical and chemical properties. Purpose: The aim of this study was to review the current published literature on the use of PEEK for the fabrication of dental prostheses with CAD-CAM techniques. Methods: Electronic database searches were performed using the terms “PEEK”, “CAD-CAM”, “dental”, “dentistry” to identify studies related to the use of PEEK for the fabrication of CAD-CAM prostheses. Results: A great number of in vitro studies are available in the current literature pointing out the noticeable properties of PEEK. The use of PEEK has been recommended for a wide range of CAD-CAM fabricated fixed and removable dental prostheses, occlusal splints, intra-radicular posts, implant abutments, customized healing abutments, space maintainers for pediatric dentistry, orthodontic appliances and provisional restorations. However, only a few clinical studies were identified. Conclusions: PEEK could be considered as a viable alternative for CAD-CAM dental appliances to well-established dental materials. Due to the scarcity of clinical data, clinical trials are needed to assess the longterm performance of PEEK prostheses.

scholarly journals Hardness of denture base and hard chair-side reline acrylic resins

2005 ◽  
Vol 13 (3) ◽  
pp. 291-295 ◽  
Author(s):  
Andrea Azevedo ◽  
Ana Lucia Machado ◽  
Carlos Eduardo Vergani ◽  
Eunice Teresinha Giampaolo ◽  
Ana Cláudia Pavarina
Keyword(s):  
Surface Hardness ◽  
Acrylic Resin ◽  
Polymerization Reaction ◽  
Time Intervals ◽  
Denture Base ◽  
Continuous Increase ◽  
Hardness Tester ◽  
Dry Storage ◽  
Base Materials ◽  
Acrylic Resins

INTRODUCTION: The hardness of denture base materials may undergo changes due to continued polymerization reaction and water uptake. However, the extent to which these processes affect the hardness of materials is still unclear. OBJECTIVE: In this study, the degree of conversion of two hard chair-side reline resins (Duraliner II-D and Kooliner-K) and one heat-cured acrylic resin (Lucitone 550-L) was evaluated indirectly by measuring the surface hardness. The effect of immersion in water on this property was also analyzed. MATERIALS AND METHODS: After processing following the manufacturers' instructions, specimens (5mm diameter and 2mm thickness) were dry stored at room temperature and the Vickers hardness (VHN) was measured with a hardness tester after 0, 2, 7, 30 and 90 days. Specimens were then immersed in water at 37ºC and hardness was evaluated after the same time intervals. Five specimens were prepared for each material. Data were analyzed by Kruskal-Wallis test (P=.01). RESULTS: When dry stored, material L showed an increase in hardness (P<.01) from 0-day (VHN=23.2) to 30-day (VHN=27.1), after which no significant change was observed. A continuous increase in hardness was observed for material D from 0-day (VHN=4.6) to 90-day dry storage (VHN=7.3). For material K, an increase in hardness was observed up to 7-day (VHN=9.2), and then leveled off (P>.01). After 2-day water storage, all materials showed a significant reduction in hardness (P<.01). CONCLUSION: In general, the hardness of the materials evaluated increased during dry storage and decreased after immersion in water.

scholarly journals Chemical Characterisation of Silanised Zirconia Nanoparticles and Their Effects on the Properties of PMMA-Zirconia Nanocomposites

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3212
Author(s):  
Saleh Zidan ◽  
Nikolaos Silikas ◽  
Suhad Al-Nasrawi ◽  
Julfikar Haider ◽  
Abdulrahman Alshabib ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Raw Materials ◽  
Flexural Modulus ◽  
Surface Hardness ◽  
Acrylic Resin ◽  
Control Group ◽  
Mean Values ◽  
Hardness Tester ◽  
Bonferroni Test ◽  
Zirconia Nanoparticles

Objectives: The objective of this study was to investigate the mechanical properties of high-impact (HI) heat-cured acrylic resin (PMMA) reinforced with silane-treated zirconia nanoparticles. Methods: Forty-five PMMA specimens reinforced with zirconia were fabricated and divided into three groups: Pure HI PMMA (control group), PMMA reinforced with 3 wt.% of non-silanised zirconia nanoparticles and PMMA reinforced with 3 wt.% of silanised zirconia nanoparticles. Silanised and non-silanised zirconia nanoparticles were analysed with Fourier Transform Infrared (FTIR) Spectroscopy. For measuring the flexural modulus and strength, a Zwick universal tester was used, and for surface hardness, a Vickers hardness tester were used. Furthermore, raw materials and fractured surfaces were analysed using Scanning Electron Microscopy (SEM). A one-way ANOVA test followed by a post-hoc Bonferroni test was employed to analyse the data. Results: The results showed that the mean values for flexural strength (83.5 ± 6.2 MPa) and surface hardness (20.1 ± 2.3 kg/mm2) of the group containing 3 wt.% treated zirconia increased significantly (p < 0.05) in comparison to the specimens in the group containing non-treated zirconia (59.9 ± 7.1 MPa; 15.0 ± 0.2 kg/mm2) and the control group (72.4 ± 8.6 MPa; 17.1 ± 0.9 kg/mm2). However, the group with silanised zirconia showed an increase in flexural modulus (2313 ± 161 MPa) but was not significantly different (p > 0.05) from the non-silanised group (2207 ± 252 MPa) and the control group (1971 ± 235 MPa). Conclusion: Silane-treated zirconia nano-filler improves the surface hardness and flexural strength of HI PMMA-zirconia nanocomposites, giving a potentially longer service life of the denture base.

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. 

scholarly journals Assessment of surface roughness changes on orthodontic acrylic resin by all-in-one spray disinfectant solutions

2020 ◽  
Vol 14 (2) ◽  
pp. 77-82
Author(s):  
Kuei-ling Hsu ◽  
Abdulrahman A. Balhaddad ◽  
Isadora Martini Garcia ◽  
Fabricio Mezzomo Collares ◽  
Louis DePaola ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Rank Test ◽  
Orthodontic Appliances ◽  
Distilled Water ◽  
Care Providers ◽  
Acrylic Resins ◽  
Parametric Data ◽  
Before And After ◽  
The Impact ◽  
Spraying Method

Background. The disinfection of orthodontic acrylic resins might change the physical and mechanicalproperties of these materials. We aimed to investigate the impact of four different commercially availabledisinfectants on the surface roughness of acrylic resins used for orthodontic appliances. Methods. Four disinfectant solutions (BirexSE, Opti-Cide3, COEfect MinuteSpray, and CaviCideSpray) were used to disinfect orthodontic acrylic resins using the spraying method. The resins weresubjected to repeated disinfection protocols. Distilled water, also applied via spraying method, was usedas a control. Surface roughness was scrutinized to examine the extent of surface topography changes bystylus profilometry. Data normality was evaluated via the Shapiro–Wilk test, followed by the WilcoxonSigned-Rank test for non-parametric data or paired Student’s t-test for parametric data to compareintra-group differences in roughness before and after the use of the disinfectant solutions. Results. Some of the disinfectants (BirexSE and CaviCide) resulted in significant changes in surfaceroughness values before and after the disinfection compared to the controls (P<0.05). The groups thatwere in contact with distilled water, Opti-Cide, and Coeffect did not exhibit significant differences insurface roughness before and after the intervention (P>0.05). However, from a clinical perspective, theresulting variations in surface roughness (<%0.15) induced by these solutions might not reflect clinicallysignificant differences. Conclusion. The use of disinfectant solutions is unlikely to harm the surface of orthodontic acrylic resins.Oral care providers need to be attentive to the interpretation and implementation of clinically significantchanges in their evidence-based approach regarding potential material damages by disinfection sprays.

scholarly journals An Assessment of Treated Greywater Reuse in Irrigation on Growth and Protein Content of Prosopis and Albizia

Horticulturae ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 38
Author(s):  
Naji K. Al-Mefleh ◽  
Yahia A. Othman ◽  
Maher J. Tadros ◽  
Amani Al-Assaf ◽  
Samer Talozi
Keyword(s):  
Protein Content ◽  
Crude Protein ◽  
Dry Weight ◽  
World Health ◽  
Quality Analysis ◽  
Distilled Water ◽  
Albizia Lebbeck ◽  
Forage Production ◽  
Water Control ◽  
Significant Difference

This study investigated the influence of treated greywater on growth and protein content of multipurpose (forage and ornamental) transplants, Prosopis juliflora L., Prosopis tamarugo L., and Albizia lebbeck L. Transplants of tested species were irrigated with treated greywater, diluted greywater (grey + distilled water, 1:1/by volume), and distilled water (control) for seven months. Water quality analysis showed that the concentrations of nutrients and heavy metals found in the greywater were within the acceptable range compared with Jordan Institution for Standard and Metrology (JISM) and the World Health Organization (WHO) thresholds for safe use of greywater. Escherichia coli found in the greywater were lower compared to JISM and WHO guidelines for the safe use of greywater. Irrigation with treated greywater increased shoot fresh weight by 24–39% and dry weight by 34–40% compared to diluted greywater and control. No significant difference in crude protein was noticed between water treatments. Prosopis species (P. juliflora Albizia lebbeck L. and P. tamarugo Albizia lebbeck L.) had higher shoot fresh (35%) and dry weight the same species had lower crude protein (44%) when compared to Albizia lebbeck Albizia lebbeck L. The reuse of treated greywater for landscaping or forage production alleviates the demand for water resources and reduces the pressure on wastewater treatment plants. However, considering the controversial findings of previous studies on greywater quality (especially, long-term reuse), the reuse of treated greywater needs to be considered with caution and periodic quality analyses and economic assessments are required.

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