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Farret MM. Orthodontic biomechanics with intermaxillary elastics. Dental Press J Orthod 2023; 28:e23spe3. [PMID: 37493850 PMCID: PMC10365070 DOI: 10.1590/2177-6709.28.3.e23spe3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/29/2023] [Indexed: 07/27/2023] Open
Abstract
INTRODUCTION Intermaxillary elastics are orthodontic resources widely used in various malocclusions. Their main advantages are low cost, easy insertion and removal by patients, and application versatility. As main disadvantages, we can highlight the need for cooperation from patients and the side effects normally present in treatments with this resource. Knowledge of the biomechanics involved in the use of intermaxillary elastics is essential to take full advantage of the desired effects and avoid unwanted effects in their use. OBJECTIVE Therefore, the objective of this article is to describe the anchorage preparation, connection methods, time and force of use, and side effects involved in the use of intermaxillary elastics for the treatment of anteroposterior, vertical and transverse problems. For that, clinical cases and biomechanics schemes will be presented, in which all these details will be described.
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Affiliation(s)
- Marcel Marchiori Farret
- Centro de Estudos Odontológicos Meridional (CEOM), Especialização em Ortodontia (Passo Fundo/RS, Brazil)
- Private practice (Santa Maria/RS, Brazil)
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Development and characterization of natural rubber latex wound dressings enriched with hydroxyapatite and silver nanoparticles for biomedical uses. REACT FUNCT POLYM 2022. [DOI: 10.1016/j.reactfunctpolym.2022.105316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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The Effect of Extrinsic Factors on the Mechanical Behavior and Structure of Elastic Dental Ligatures and Chains. Polymers (Basel) 2021; 14:polym14010038. [PMID: 35012064 PMCID: PMC8747250 DOI: 10.3390/polym14010038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 11/16/2022] Open
Abstract
Force provided by elastomers used in orthodontics can be affected by several factors present in the oral cavity. The aim of our study was to investigate the role of mouthwashes, toothbrushing, and smoking in the force decay of such elastomers. Tensile strength, changes in the force continuously exerted, and force decay of elastic chains (Ortho Organizer and Masel Short Power Chain) and elastic ligatures (Dentaurum and Masel) by two separate manufacturers were measured. Measurements were initially made on untreated elastics, followed by exposure to different environmental factors including cigarette smoke, toothbrushing (mechanical plaque control), and two different mouthwashes (chemical plaque control). Changes on the surface of the elastics were studied with scanning electron microscopy (SEM). Untreated Masel elastic ligature showed lower tensile strength than Dentaurum elastic ligature (2339 cN vs. 3660 cN), while significantly higher tensile strength was measured for Ortho Organizer elastic chains than Masel chains (2639 cN vs. 1324 cN). The decrease in the elastic force of Masel ligature was greater in response to all external factors compared to Dentaurum. Although brushing with toothpaste and toothbrush impacted the force of both Masel and Ortho organizer ligatures negatively, force degradation was more apparent in the case of the Ortho organizer. Surface changes were more visible when applying Curasept mouthrinse, however force decay was higher in the Corsodyl group. Mechanical and chemical plaque control can influence the tensile strength and force decay of orthodontic elastomers, which should be considered by selecting the elastomers or determining their changing interval for the practice.
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Olszewska A, Hanć A, Barałkiewicz D, Rzymski P. Metals and Metalloids Release from Orthodontic Elastomeric and Stainless Steel Ligatures: In Vitro Risk Assessment of Human Exposure. Biol Trace Elem Res 2020; 196:646-653. [PMID: 31686396 PMCID: PMC7306017 DOI: 10.1007/s12011-019-01936-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 10/14/2019] [Indexed: 02/07/2023]
Abstract
Elastomeric ligatures are increasingly used as a part of esthetic orthodontic treatment, particularly in children. The aim of the present study was to experimentally test whether these appliances may contribute to exposure to toxic elements. In the present study, elastomeric ligatures (ELs) were incubated in artificial human saliva for 1 month (a typical period of their use) and the release of 21 metals (Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mg, Mo, Ni, Pb, Rb, Tl, Ti, Sb, Sr, Sn, Zn, U, V) and 2 metalloids (As and Ge) was studied using inductively coupled plasma-mass spectrometry. For comparison, stainless steel ligatures (SLs) were incubated for 1, 3, and 6 months (since sometimes their use is prolonged) under similar conditions. The determined metal levels were compared to the corresponding safety limits for human exposure. During 1 month, the ELs released Cd, Co, Cr, Mn, Ni, and Sn at total mean ± SD level of 0.31 ± 0.09, 0.98 ± 0.30, 3.96 ± 1.31, 14.7 ± 8.5, 13.8 ± 4.8, and 49.5 ± 27.7 μg, respectively. Other elements were always below the detection limits. In case of SL, the release of Co, Cr, Fe, Ni, Mn, and Sn was observed, and the determined values increased over the studied period. After 6 months, their total mean ± SD levels amounted to 28.6 ± 0.2, 21.7 ± 0.2, 623.5 ± 3.0, 1152.7 ± 1.8, 5.5 ± 0.3, and 22.6 ± 0.2 μg, respectively. The released metal levels from both ligature types were always below safety limits. The release of Ni from SL during 6 months would constitute 5.0 and 11.5% of tolerable intake in adults and children, respectively. The results of this in vitro study highlight that the use of ligatures in orthodontic treatment can be considered safe in terms of metal exposure although elastic ligatures replaced on a monthly basis appear to be advantageous in comparison to the prolonged use of stainless steel appliances.
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Affiliation(s)
- Aneta Olszewska
- Department of Facial Malformation, Poznan University of Medical Sciences, Poznań, Poland
| | - Anetta Hanć
- Department of Trace Element Analysis by Spectrometry Method, Faculty of Chemistry, Adam Mickiewicz University, Poznań, Poland
| | - Danuta Barałkiewicz
- Department of Trace Element Analysis by Spectrometry Method, Faculty of Chemistry, Adam Mickiewicz University, Poznań, Poland
| | - Piotr Rzymski
- Department of Environmental Medicine, Poznan University of Medical Sciences, Poznań, Poland.
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Abstract
OBJECTIVES To investigate the potential cytotoxicity of the bracket identification dyes commonly used in orthodontic fixed appliances. MATERIALS AND METHODS Six bracket brands representing the market in various aspects were selected. Ten sets of each bracket brand were acquired, and the identification dyes on them were scraped. They were tested for cytotoxicity at three different levels of concentration (2.5 mg/mL, 5 mg/mL, and 10 mg/mL), with the aid of a real-time cell analysis system. The results were compared within and between the groups. One-way analysis of variance and Tukey's post hoc test were used for statistical analysis. RESULTS None of the six investigated dyes displayed cytotoxicity at the 2.5 mg/mL concentration. Of the investigated brands, three at 5 mg/mL and four at 10 mg/mL displayed cytotoxicity. CONCLUSIONS Some of the identification dyes in this study did display cytotoxicity at the higher concentrations tested. Alternative methods for bracket identification should be considered.
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Synthesis and characterization of novel biodegradable water dispersed poly(ether-urethane)s and their MWCNT-AS nanocomposites functionalized with aspartic acid as dispersing agent. IRANIAN POLYMER JOURNAL 2018. [DOI: 10.1007/s13726-018-0655-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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dos Santos RL, Pithon MM, Carvalho FG, Ramos AADS, Romanos MTV. Mechanical and biological properties of acrylic resins manipulated and polished by different methods. Braz Dent J 2015; 24:492-7. [PMID: 24474291 DOI: 10.1590/0103-6440201302293] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Accepted: 09/03/2013] [Indexed: 11/21/2022] Open
Abstract
This study evaluated the influence of the manipulation technique and polishing method on the flexural strength and cytotoxicity of acrylic resins. Two manipulation techniques and three polishing methods were used in the fabrication of acrylic plates that were divided into 6 groups (n=10). Groups MM, MC and MW: mass technique with mechanical polishing, chemical polishing and without polishing, respectively; and Groups SM, SC and SW: Saturation technique with mechanical polishing, chemical polishing and without polishing, respectively). Flexural strength was tested in a universal testing machine and the cytotoxicity assay used cell cultures (L-929) for periods of 24 h to 168 h. Flexural strength and cytotoxicity data were assessed using two-way and three-way ANOVA, respectively (α=0.05), followed by post hoc Bonferroni test for multiple comparisons. The effect of combinations of manipulation techniques and polishing methods on flexural strength showed significant differences only between Group SC and Groups MW, MM and MC (p<0.01). Cell viability ranged from 51% (3.9%) to 87,6% (3.2) in the 24-h time interval, and from 87.8% (5.0) to 95.7% (3.1%) in the 168-h time interval. With the increase of cell viability, from the third day (72 h), there was no significant difference among the groups, except between MM and SC (p<0.01) at 72 h. In conclusion, the manipulation technique and polishing method had more influence on the cytotoxicity than on flexural strength.
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Affiliation(s)
- Rogério Lacerda dos Santos
- Department of Orthodontics and Pediatric Dentistry, UFCG - Federal University of Campina Grande, PatosPB, Brazil
| | - Matheus Melo Pithon
- Department of Orthodontics, UESB - State University of Southwest Bahia, JequiéBA, Brazil
| | - Fabiola Galbiatti Carvalho
- Department of Orthodontics and Pediatric Dentistry, UFCG - Federal University of Campina Grande, PatosPB, Brazil
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Cytotoxicité de la chaînette élastomérique dans la salive artificielle : étude in vitro. Int Orthod 2015. [DOI: 10.1016/j.ortho.2014.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Halimi A, Azeroual MF, Eddimani L, Natiq A, Bakri Y, Zaoui F. Cytotoxicity of elastomeric power chains in artificial saliva: an in vitro study. Int Orthod 2015; 13:16-25. [PMID: 25703073 DOI: 10.1016/j.ortho.2014.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
INTRODUCTION The main aim of this paper is to investigate the cytotoxicity of elastomeric power chains after stretching and immersion in a solution of artificial saliva. MATERIALS AND METHOD Two brands of grey polyurethane power chains available from two different firms (GAC, G&H) were selected for cytotoxicity assay. Each segment was stretched up to an initial force of approximately 200 g. Then each segment was kept stretched using appropriate equipment. The samples were tested in artificial saliva at two pH levels, pH7 and pH4. Following incubation, the saliva was removed, filtered and placed in contact with cell culture media using the RD line. RESULTS AND DISCUSSION At this supernatant dilution, no statistically significant difference was observed between the different groups of power chains studied in terms of cell viability. The GAC and G&H power chains, whether stretched or not and immerged in either pH7 or pH4 saliva, showed no toxic effect on RD cells (human cell line).
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Affiliation(s)
- Abdelali Halimi
- M.M.B Biotechnology and Biomechanics Research team, service d'orthopédie dento-faciale, centre hospitalier Ibn Sina, faculté de médecine dentaire, université Mohammed V - Souissi (UM5S), avenue Allal Al Fassi, rue Mohammed Jazouli, BP 6212, Rabat, Morocco.
| | - Mohamed-Faouzi Azeroual
- M.M.B Biotechnology and Biomechanics Research team, service d'orthopédie dento-faciale, centre hospitalier Ibn Sina, faculté de médecine dentaire, université Mohammed V - Souissi (UM5S), avenue Allal Al Fassi, rue Mohammed Jazouli, BP 6212, Rabat, Morocco
| | - Latifa Eddimani
- Département de biologie et immunologie, faculté des sciences, université Mohammed V - Agdal (UM5A), 4, avenue Ibn Battouta, BP 1014, Rabat, Morocco
| | - Abdelhafid Natiq
- Département de génétique médicale, Institut national d'hygiène, université Mohammed V - Souissi (UM5S), 27, avenue Ibn Battouta, 10090 Rabat, Morocco
| | - Youssef Bakri
- Département de biologie et immunologie, faculté des sciences, université Mohammed V - Agdal (UM5A), 4, avenue Ibn Battouta, BP 1014, Rabat, Morocco
| | - Fatima Zaoui
- M.M.B Biotechnology and Biomechanics Research team, service d'orthopédie dento-faciale, centre hospitalier Ibn Sina, faculté de médecine dentaire, université Mohammed V - Souissi (UM5S), avenue Allal Al Fassi, rue Mohammed Jazouli, BP 6212, Rabat, Morocco
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Leão Filho JCB, Gallo DB, Santana RM, Guariza-Filho O, Camargo ES, Tanaka OM. Influence of different beverages on the force degradation of intermaxillary elastics: an in vitro study. J Appl Oral Sci 2013; 21:145-9. [PMID: 23739862 PMCID: PMC3881875 DOI: 10.1590/1678-7757201302256] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 01/30/2013] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE The aim of this study was to evaluate in vitro the effects of frequently ingested beverages on force degradation of intermaxillary elastics. MATERIAL AND METHODS One hundred and eighty 1/4-inch intermaxillary elastics (TP Orthodontics) were immersed into six different beverages: (1) Coca-Cola®; (2) Beer; (3) Orange juice; (4) Red wine; (5) Coffee and (6) artificial saliva (control). The period of immersion was 15 min for the first and second cycles and 30 min for the third to fifth cycles. Tensile forces were read in a tensile testing machine before and after the five immersion cycles. One-way repeated measures ANOVA was used to identify significant differences. RESULTS Force degradation was seen in all evaluated groups and at all observation periods (p<0.05). A greater degree of degradation was present at the initial periods, decreasing gradually over time. However, no statistically significant differences were seen among groups at the same periods, showing that different groups behaved similarly. CONCLUSION The chemical nature of the evaluated beverages was not able to influence the degree of force degradation at all observation periods.
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Baratieri C, Mattos CT, Alves M, Lau TCL, Nojima LI, de Souza MMG, Araujo MT, Nojima MDCG. In situ evaluation of orthodontic elastomeric chains. Braz Dent J 2012. [PMID: 23207855 DOI: 10.1590/s0103-64402012000400014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The hypothesis tested in this study was that intraoral exposure of elastomeric chains alters their tensile strength. For such purpose, it was evaluated the in situ behavior of different elastomeric chains stretched for 3 weeks. Three kinds of elastomeric chains, Plastic chain (PC), Memory chain (MC) and Super slick chain (SSC), were randomly placed in 3 quadrants of 13 patient in a fixed distance of 16 mm and mean initial force of 180 g. Tensile testing was performed in an universal testing machine at different intervals: initial, 1 h, 24 h, 1 week, 2 weeks and 3 weeks. A two-way ANOVA test was performed to identify the influence of both material and time on the force decrease. A subsequent one-way ANOVAtest with the Tukey's post hoc test was used to identify statistically significant intragroup and intergroup remaining force (g and %) differences at 5% significance level. The effect of both the material and the time factors were significant. All groups showed significant force decrease after the 1-h period (23% for PC and 14% for MC and SSC). At the end of the 3-week period, the remaining force was 57% (96 g), 67% (129 g) and 71% (125 g) for PC, MC and SSC, respectively. In conclusion, intraoral exposure of elastomeric chains altered their tensile strength. In general, the greater force decrease occurred within the first hour. The remaining force of the enhanced chains measured at each time interval was greater than the conventional one (PC). After 3 weeks, only the enhanced chains maintained the force applied over 100 g.
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Affiliation(s)
- Carolina Baratieri
- Department of Orthodontics, Dental School, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Cytotoxicity of esthetic, metallic, and nickel-free orthodontic brackets: cellular behavior and viability. Am J Orthod Dentofacial Orthop 2012; 142:70-4. [PMID: 22748992 DOI: 10.1016/j.ajodo.2012.02.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 02/01/2012] [Accepted: 02/01/2012] [Indexed: 11/21/2022]
Abstract
INTRODUCTION In this study, we evaluated the cellular viability of various esthetic, metallic, and nickel-free orthodontic brackets. METHODS The sample was divided into 11 groups (n = 8): cellular control, negative control, positive control, metallic, polycarbonate, 2 types of monocrystalline ceramic, 3 types of nickel free, and polycrystalline ceramic brackets. Cell culture (NIH/3T3-mice fibroblasts) was added to the plates of 96 wells containing the specimens and incubated in 5% carbon dioxide at 37°C for 24 hours. Cytotoxicity was analyzed qualitatively and quantitatively. Cell growth was analyzed with an inverted light microscope, photomicrographs were obtained, and the results were recorded as response rates based on modifications of the parameters of Stanford according to the size of diffusion halo of toxic substances. Cell viability was analyzed (MTT assay); a microplate reader recorded the cell viability through the mitochondrial activity in a length of 570 nm. The values were statistically analyzed. RESULTS All tested brackets had higher cytotoxicity values than did the negative control (P <0.05), with the exception Rematitan and Equilibrium (both, Dentaurum, Ispringen, Germany) (P >0.05), suggesting low toxicity effects. The values showed that only polycarbonate brackets were similar (P >0.05) to the positive control, suggesting high toxicity. CONCLUSIONS The brackets demonstrated different ranges of cytotoxicity; nickel-free brackets had better biocompatibility than the others. On the other hand, polycarbonate brackets were made of a highly cytotoxic material for the cells analyzed.
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Lacerda Dos Santos R, Pithon MM, Romanos MTV. The influence of pH levels on mechanical and biological properties of nonlatex and latex elastics. Angle Orthod 2011; 82:709-14. [PMID: 22149622 DOI: 10.2319/082811-552.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To evaluate the influence of pH levels on interarch elastics with regard to force decay and cytotoxicity. MATERIALS AND METHODS One nonlatex (NLAO) group and one latex (LAO) group were tested (n = 10). Elastics were stretched to 25 mm and were held for 1, 6, 12, and 24 hours in artificial saliva solutions with pH levels of 5.0, 6.0, and 7.5. Force magnitudes were measured at 25 mm of activation. The cytotoxicity assay was performed using cell cultures (L929 mouse fibroblast cell line), which were subjected to the cell viability test with neutral red ("dye-uptake"). Force decay and cytotoxicity were assessed using analysis of variance, the Sidak method, and a Tukey's test. RESULTS The interactions between group, pH, and time showed no statistically significant differences (P = .29). When pH per time (P = .032) and group per time (P = .0009) were considered, these interactions showed statistically significant differences (P < .05). The pH did not interfere directly in the degradation results of the tested elastics. The cytotoxicity test showed that group LAO presented lower cell viability when compared with group NLAO over the course of the entire experiment. There was a gradual reduction in cell viability from 1 hour to 24 hours. A significant difference (P < .05) was found between the interactions group pH and the control group of cells, except between group NLAO at the time point of 1 hour at different pH values and at the time points of 6 and 12 hours with pH 5 (P > .05). CONCLUSIONS No significant correlation between pH, force decay, and cytotoxicity was observed.
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