Orthodontic Research Today is a free monthly online journal that collates and summarizes the latest research about Orthodontic, including details on braces, retainers, treatment.

Application of shape memory polyurethane in orthodontic.

Jung YC, Cho JW

Department of Textile Engineering, Konkuk University, Seoul, 143-701, Korea.

A shape memory polymer wire for orthodontic application was prepared by melt-spinning of polyurethane block copolymer (PU) which was synthesized in a two-step process from a reaction of 4,4'-methylene bis(phenylisocyanate), poly(epsilon-caprolactone)diol (PCL), and 1,4-butanediol. An orthodontic test using the PU wire was carried out in an orthodontic model with a metal bracket. High shape recovery force of 70 gf for PU wire at 40 wt% hard segment content could be preserved for even 1 month after a shape recovery force test at a constant temperature of 50 degrees C. The shape recovery force decreased exponentially during the initial 2 h, but reached an equilibrium shape recovery force of 50 gf after about 20 days. It was found that this shape recovery force was sufficient to correct misaligned teeth in the orthodontic test. The shape memory PU wire possesses strong potential as a novel orthodontic appliance with esthetically appealing appearance.

Published 24 July 2008 in J Mater Sci Mater Med.
Full-text of this article is available online (may require subscription).

Articles on Orthodontic published 23 July 2008:

Orthodontic treatment of a patient with recessive dystrophic epidermolysis bullosa: a case report.   Spec Care Dentist, 28(4): 136-9.

Epidermolysis bullosa (EB) represents a heterogeneous group of hereditary, chronic, non-inflammatory skin pathologies. Recessive dystrophic epidermolysis bullosa (RDEB) is characterized by sub-lamina dura separation, due to blistering below the lamina densa of the basement membrane zone, and is associated with the absence of Type VII collagen fibers. The mouth, pharyngeal, and esophageal mucosa are compromised by scarring and tissue contraction. The purpose of this article was to present a case ... [Abstract] [Full-text]

Articles on Orthodontic published 22 July 2008:

Duration of surgical-orthodontic treatment.   Acta Odontol Scand.

Objective. To study the duration of surgical-orthodontic treatment with special reference to patients' age and the type of tooth movements, i.e. extraction vs. non-extraction and intrusion before or extrusion after surgery to level the curve of Spee. Material and methods. The material consisted files of 37 consecutive surgical-orthodontic patients. The files were reviewed and gender, diagnosis, type of malocclusion, age at the initiation of treatment, duration of treatment, type of tooth ... [Abstract] [Full-text]

Articles on Orthodontic published 17 July 2008:

Is the Royal London Space Analysis reliable and does it influence orthodontic treatment decisions?   Eur J Orthod.

The purpose of this study was to investigate the reliability of the Royal London Space Analysis (RLSA) and to evaluate its influence on orthodontic treatment decisions. Thirty-one case records were collected to represent various levels of crowding and different types of malocclusions. Seventeen examiners assessed these records and completed a data sheet that recorded information on their treatment decision. One month later, the examiners attended a course on the RLSA and then used the analysis ... [Abstract] [Full-text]

Experimental antimicrobial orthodontic adhesives using nanofillers and silver nanoparticles.   Dent Mater.

OBJECTIVES: Experimental composite adhesives (ECAs) containing silica nanofillers and silver nanoparticles were compared with two conventional adhesives (composite and resin-modified glass ionomer [RMGI]) to analyze surface characteristics, physical properties and antibacterial activities against cariogenic streptococci. METHODS: Surface roughness and surface free energy (SFE) characteristics were measured using confocal laser scanning microscopy and the sessile drop method. Shear bond strength ... [Abstract] [Full-text]

Articles on Orthodontic published 11 July 2008:

Influence of different brazing and welding methods on tensile strength and microhardness of orthodontic stainless steel wire.   Eur J Orthod.

The aim of this study was to compare the mechanical strength and microhardness of joints made by conventional brazing and tungsten inert gas (TIG) and laser welding. A standardized end-to-end joint configuration of the orthodontic wire material in spring hard quality was used. The joints were made using five different methods: brazing (soldering > 450 degrees C) with universal silver solder, two TIG, and two laser welders. Laser parameters and welding conditions were used according to the ... [Abstract] [Full-text]

Impaction and apical root angulation of the maxillary central incisors due to supernumerary teeth: combined surgical and orthodontic treatment.   Am J Orthod Dentofacial Orthop, 134(1): 153-60.

This case report describes the treatment of a boy with both central maxillary incisors impacted because of 2 supernumerary teeth. Therapeutic management of the impacted teeth was combined with orthodontic treatment of a Class II Division 1 malocclusion. A sequential approach of surgical removal of the supernumerary teeth with 2 stages of surgical exposure and orthodontic traction of the impacted teeth resulted in proper incisor positioning. Close monitoring and multidisciplinary cooperation ... [Abstract] [Full-text]

Influence of orthodontic intrusion on pulpal vitality of previously traumatized maxillary permanent incisors.   Am J Orthod Dentofacial Orthop, 134(1): 12-7.

INTRODUCTION: Dental trauma seems to increase a patient's susceptibility to complications during orthodontic treatment. However, no previous investigation has examined the influence of orthodontic intrusion on pulpal vitality of traumatized maxillary permanent incisors. METHODS: Pulpal condition was examined clinically and radiologically after orthodontic intrusion of previously traumatized (OT group) and nontraumatized teeth (O group), and after previous dental trauma without orthodontic ... [Abstract] [Full-text]

Orthodontic extraction of mandibular third molar to avoid nerve injury and promote periodontal healing.   J Clin Periodontol.

Aim: Impacted mandibular third molar extraction is a common procedure in oral surgery, not without risk of nerve injury and periodontal defects on the distal aspect of the adjacent second molar. The "orthodontic extraction" is proposed as a method to avoid mandibular nerve injury during the extraction of a deeply embedded third molar and to prevent or limit such periodontal problems. Material and Methods: A 28-year-old man presented a deeply impacted left mandibular third molar that ... [Abstract] [Full-text]

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