Baltic Dental and Maxillofacial Journal
Main page Back issues Editorial board Information

June, 2009, Vol. 11, No. 2

CONTENTS

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