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Stomatologija 2009; 11 (2): 66-69 239 KB

Evaluation of tensile strength of different configurations of orthodontic retraction loops for obtaining optimized forces

Miceli Beck Guimaraes Blaya, Graziela Henriques Westphalen, Magali Beck Guimaraes, Luciana Mayumi Hirakata

Summary

The aim of this study was to analyze the mechanical behavior of different orthodontic retraction loops. Two designs of orthodontic loops for closing space were analyzed: teardrop-shaped (T) and circle-shaped loop (C), of two different heights (6 and 8 mm), and two types of orthodontic wires (stainless steel – 0.19’ × 0.25’; TMA – titanium molybdenum alloy – 0.016’ × 0.016’). The sample consisted of 80 loops, divided into 8 groups determined by the combination shape/height/type of wire, which were submitted to tensile testing at a speed of 2 mm/min., to measure the quantity of force generated when activated in the interval of 0.75 mm and 2.25 mm. The results were submitted to the ANOVA and Tukey statistical tests to compare the groups, and the Student’s-t test to compare the means of two groups. Statistically higher values were observed for the size 6 mm, circle shape and stainless steel composition. The group “teardrop-8 mm-TMA” together with the group “circle-8 mm-TMA” presented the lowest mean value, differing statistically from all of the other groups. It was concluded that the alloy of the wire and the height of the loop would be more important than the loop design.

Key words: orthodontics, orthodontic loop, retraction.

Received: 14 10 2008

Accepted for publishing: 19 06 2009

*Pontifical Catholic University of Rio Grande do Sul, Brazil

Miceli Beck Guimaraes Blaya* – D.D.S, PhD Student

Graziela Henriques Westphalen* – D.D.S, M.S., PhD Student

Magali Beck Guimaraes*– D.D.S, M.S. Student

Luciana Mayumi Hirakata* – D.D.S, M.S., PhD, Dental Material Professor.

Address correspondence to Dr. Luciana Mayumi Hirakata, Av. Ipiranga, 6681 - Building 6, Porto Alegre – Rio Grande do Sul, Brazil, Zip code: 90619-900.

E-mail: lucianahirakata@yahoo.com.br



	Baltic Dental and Maxillofacial Journal

June, 2009, Vol. 11, No. 2 CONTENTS ABSTRACTS The 1st Baltic Sea Conference in Orthognathic Surgery and Orthodontics (BSCOSO 2009). September 24-27, 2009, Vilnius, Lithuania SCIENTIFIC ARTICLES Evaluation of dental care and the prevalence of tooth decay among middle-aged and elderly population of Kaunas city Jurate Zubiene, Simona Milciuviene, Jurate Klumbiene 42-47 Growth factors/cytokines/defensins and apoptosis in periodontal pathologies Zane Laurina, Mara Pilmane, Ruta Care 48-54 Stress distribution of an internal connection implant prostheses set: A 3D finite element analysis Regenio Mahfuz Herbstrith Segundo, Hugo Mitsuo Silva Oshima, Isaac Newton Lima da Silva, Luis Henrique Burnnet Junior, Eduardo Goncalves Mota, Liangrid Lutiani Silva 55-59 Intra-articular injection of hyaluronic acid for temporomandibular joint osteoarthritis in elderly patients Luca Guarda-Nardini, Daniele Manfredini, Marco Stifano, Alberto Staffieri, Gino Marioni 60-65 Evaluation of tensile strength of different configurations of orthodontic retraction loops for obtaining optimized forces Miceli Beck Guimaraes Blaya, Graziela Henriques Westphalen, Magali Beck Guimaraes, Luciana Mayumi Hirakata 66-69 © 2009 Stomatologija		Stomatologija 2009; 11 (2): 66-69 239 KB Evaluation of tensile strength of different configurations of orthodontic retraction loops for obtaining optimized forces Miceli Beck Guimaraes Blaya, Graziela Henriques Westphalen, Magali Beck Guimaraes, Luciana Mayumi Hirakata Summary The aim of this study was to analyze the mechanical behavior of different orthodontic retraction loops. Two designs of orthodontic loops for closing space were analyzed: teardrop-shaped (T) and circle-shaped loop (C), of two different heights (6 and 8 mm), and two types of orthodontic wires (stainless steel – 0.19’ × 0.25’; TMA – titanium molybdenum alloy – 0.016’ × 0.016’). The sample consisted of 80 loops, divided into 8 groups determined by the combination shape/height/type of wire, which were submitted to tensile testing at a speed of 2 mm/min., to measure the quantity of force generated when activated in the interval of 0.75 mm and 2.25 mm. The results were submitted to the ANOVA and Tukey statistical tests to compare the groups, and the Student’s-t test to compare the means of two groups. Statistically higher values were observed for the size 6 mm, circle shape and stainless steel composition. The group “teardrop-8 mm-TMA” together with the group “circle-8 mm-TMA” presented the lowest mean value, differing statistically from all of the other groups. It was concluded that the alloy of the wire and the height of the loop would be more important than the loop design. Key words: orthodontics, orthodontic loop, retraction. Received: 14 10 2008 Accepted for publishing: 19 06 2009 Pontifical Catholic University of Rio Grande do Sul, Brazil Miceli Beck Guimaraes Blaya – D.D.S, PhD Student Graziela Henriques Westphalen* – D.D.S, M.S., PhD Student Magali Beck Guimaraes– D.D.S, M.S. Student Luciana Mayumi Hirakata – D.D.S, M.S., PhD, Dental Material Professor. Address correspondence to Dr. Luciana Mayumi Hirakata, Av. Ipiranga, 6681 - Building 6, Porto Alegre – Rio Grande do Sul, Brazil, Zip code: 90619-900. E-mail: lucianahirakata@yahoo.com.br