Second molar intrusion: Continuous arch or loop mechanics?

Introduction: Our aim was to compare the load systems produced by rectangular loops and continuous arch mechanics on intrusion of a maxillary second molar.

Methods: An orthodontic appliance was passively bonded from second molar to second molar on a patient's model fixed to an orthodontic force tester. The second molars were extruded by 3 mm, and 2 mechanics systems were compared: beta-titanium rectangular loops and super-elastic nickel-titanium continuous arch.

Welding strength of NiTi wires.

Objective: To identify the appropriate power level for electric welding of three commercial brands of nickel-titanium (NiTi) wires.

Methods: Ninety pairs of 0.018-in and 0.

Effects of reducing light-curing time of a high-power LED device on shear bond strength of brackets.

Purpose: To assess the effects of reducing the curing time of a high-power light-emitting diode (LED) unit (Valo, Ultradent, South Jordan, UT, USA) on shear bond strength (SBS) of metal brackets and on the amount of adhesive remnant of two orthodontic composites.

Methods: Eighty human premolars were divided into four groups (G1-4) according to curing time and composite: G1 (Transbond XT, 6 s), G2 (Opal Bond MV, 6 s), G3 (Transbond XT, 3 s), and G4 (Opal Bond MV, 3 s). Twenty-four hours after bonding, brackets were subject to a SBS test performed with a universal testing machine.

Evaluation of the load system produced by a single intrusion bend in a maxillary lateral incisor bracket with different alloys.

Objectives: To evaluate if a 0.5-mm vertical bend applied on an incisor bracket produces movements in other planes and if different wires influence these effects.

Materials And Methods: An acrylic model of a treated patient with brackets passively bonded was attached to an Orthodontic Force Tester, and a load cell was attached to the left lateral incisor.

Continuous arch and rectangular loops for the correction of consistent and inconsistent load systems in extruded and tipped maxillary second molars.

Introduction: The aim of this research was to compare the load systems produced by rectangular loops and continuous arches for the correction of extruded second molars with a mesial inclination (inconsistent system) and a distal inclination (consistent system).

Methods: The maxillary first molar of an acrylic model of a patient, with passive brackets and tubes bonded, was connected to a 3-dimensional load cell of an orthodontic force tester, and the second molar was replaced by its respective tube bonded to a second load cell. The second molar tube was moved 2.

Stability of beta-titanium T-loop springs preactivated by gradual curvature.

Objective: Evaluate changes in the force system of T-Loop Springs (TLS) preactivated by curvature, due to stress relaxation.

Methods: Ninety TLSs measuring 6 x 10 mm, produced out with 0.017 x 0.

Deformation of nickel-titanium closed coil springs: an in vitro study.

Objective: The aim of this paper was to determine the amount of deformation in four commercial brands of nickel-titanium closed springs.

Methods: A total of 130 springs were divided into 13 subgroups, according to their features and manufacturers (Morelli, Orthometric, Ormco and GAC) and activated from 100% to 1000% of the effective length of the nickel-titanium portion present at the spring, at 37 °C. Deactivation data were plotted and deformation was found graphically.

Assessing adhesive remnant removal and enamel damage with ultraviolet light: An in-vitro study.

Introduction: Our objective was to assess the amounts of adhesive remnant and enamel damage when removing composite under conventional lighting and ultraviolet (UV) light.

Methods: Thirty-eight premolars were divided into 2 groups according to the lighting used for adhesive removal. A multifluted tungsten-carbide bur at low speed was used for this process in both groups.

Superelasticity and force plateau of nickel-titanium springs: an in vitro study.

Objective: This paper analyzed whether nickel-titanium closed coil springs (NTCCS) have a different superelastic (SE) behavior according to activation and whether their force plateau corresponds to that informed by the manufacturer.

Methods: A total of 160 springs were divided into 16 subgroups according to their features and activated proportionally to the length of the extensible part (NiTi) of the spring (Y). The force values measured were analyzed to determine SE rates and force plateaus, which were mathematically calculated.

Nickel titanium T-loop wire dimensions for en masse retraction.

Objective: To compare the force system produced by nickel-titanium T-loop springs made with wires of different dimensions.

Material And Methods: Thirty compound T-loop springs were divided into three groups according to the dimensions of the nickel-titanium wire used for its design: 0.016" × 0.

Differences in the force system delivered by different beta-titanium wires in elaborate designs.

Objective: Evaluation of the force system produced by four brands of b-Ti wires bent into an elaborate design.

Methods: A total of 40 T-loop springs (TLS) hand-bent from 0.017 x 0.

Effect of clinical use of nickel-titanium springs.

Introduction: Our objectives were to determine whether there are changes on the load deflection rate (L/DP) and the average force (FP) of the superelastic pseudoplateau, and whether permanent deformation is changed in nickel-titanium closed-coil springs (CCSs) after 6 months of clinical use.

Methods: Twenty-two nickel-titanium CCSs (Sentalloy 100 g; Dentsply GAC, York, Pa) were subjected to tensile mechanical testing at 37°C on activations varying from 3.2 to 16.

Comparison surface characteristics and chemical composition of conventional metallic and nickel-free brackets.

This study aims at comparing conventional and nickel-free metal bracket surface characteristics with elemental composition by scanning electron microscopy (SEM), using energy dispersive spectroscopy (EDS). The sample consisted of 40 lower incisor brackets divided into four groups: ABZ = conventional brackets, Kirium Abzil 3M® (n = 10); RL = conventional brackets, Roth Light Morelli® (n = 10); NF = nickel-free brackets, Nickel-Free Morelli® (n = 10); and RM = nickel-free brackets, Roth Max Morelli® (n = 10). Qualitative evaluation of the bracket surface was performed using SEM, whereby surface features were described and compared.

Orthodontic Treatment in Adult Patient with Reduced Periodontium: A Case Report.

Patients presenting reduced periodontium represent a major concern for orthodontists. The purpose of this article is to present the clinical case of an adult patient who presented sequel of periodontal disease (diastemas) compromising her dental aesthetics. She was subjected to an orthodontic treatment with the application of light forces distant from the teeth with reduced periodontium.

Lateral cephalometric diagnosis of asymmetry in Angle Class II subdivision compared to Class I and II.

Introduction: Lateral cephalometric radiographs are traditionally required for orthodontic treatment, yet rarely used to assess asymmetries.

Objective: The objective of the present study was to use lateral cephalometric radiographs to identify existing skeletal and dentoalveolar morphological alterations in Class II subdivision and to compare them with the existing morphology in Class I and II relationship.

Material And Methods: Ninety initial lateral cephalometric radiographs of male and female Brazilian children aged between 12 to 15 years old were randomly and proportionally divided into three groups: Group 1 (Class I), Group 2 (Class II) and Group 3 (Class II subdivision).

Time reduction of light curing: Influence on conversion degree and microhardness of orthodontic composites.

Introduction: The aim of this study was to assess the influence of curing time and power on the degree of conversion and surface microhardness of 3 orthodontic composites.

Methods: One hundred eighty discs, 6 mm in diameter, were divided into 3 groups of 60 samples according to the composite used-Transbond XT (3M Unitek, Monrovia, Calif), Opal Bond MV (Ultradent, South Jordan, Utah), and Transbond Plus Color Change (3M Unitek)- and each group was further divided into 3 subgroups (n = 20). Five samples were used to measure conversion, and 15 were used to measure microhardness.

Mandibular growth and dentoalveolar development in the treatment of class II, division 1, malocclusion using Balters Bionator according to the skeletal maturation.

Objective: The purpose of the study was to evaluate the influence of the skeletal maturation in the mandibular and dentoalveolar growth and development during the Class II, division 1, malocclusion correction with Balters bionator.

Methods: Three groups of children with Class II, division 1, malocclusion were evaluated. Two of them were treated for one year with the bionator of Balters appliance in different skeletal ages (Group 1: 6 children, 7 to 8 years old and Group 2: 10 children, 9 to 10 years old) and the other one was followed without treatment (

Control Group: 7 children, 8 to 9 years old).

Crimpable double tubes for segmental retraction.

When a T-loop is used in segmental mechanics, it is generally attached posteriorly to an auxiliary tube in the first molars and anteriorly to a crimpable cross tube or a Burstone canine bracket. This article illustrates the use of a crimpable tube with a 90-degree bend on the base wire to secure a T-loop in segmental retraction. Both of these approaches allow a T-loop to be reactivated in a simple manner without undesirable changes in the system of forces, which could happen if the T-loop is skewed posteriorly.

Molecular detection of in-vivo microbial contamination of metallic orthodontic brackets by checkerboard DNA-DNA hybridization.

Introduction: Knowing the microbiota that colonizes orthodontic appliances is important for planning strategies and implementing specific preventive measures during treatment. The purpose of this clinical trial was to evaluate in vivo the contamination of metallic orthodontic brackets with 40 DNA probes for different bacterial species by using the checkerboard DNA-DNA hybridization (CDDH) technique.

Methods: Eighteen patients, 11 to 29 years of age having fixed orthodontic treatment, were enrolled in the study.

Paresthesia during orthodontic treatment: case report and review.

Paresthesia of the lower lip is uncommon during orthodontic treatment. In the present case, paresthesia occurred during orthodontic leveling of an extruded mandibular left second molar. It was decided to remove this tooth from the appliance and allow it to relapse.

Effects of stress relaxation in beta-titanium orthodontic loops.

Introduction: This study evaluates the changes in the force system of the beta-titanium T-loop spring (TLS) caused by stress relaxation.

Methods: Ninety TLSs with dimensions of 6 × 10 mm, made of 0.017 × 0.

Force system evaluation of symmetrical beta-titanium T-loop springs preactivated by curvature and concentrated bends.

Introduction: The objective of this research was to compare the effect of preactivation on the force system of beta-titanium T-loop springs (TLSs).

Methods: Twenty TLSs with dimensions of 6 × 10 mm, of 0.017 × 0.

Composite pontics for orthodontic patients with extraction spaces.

Esthetic orthodontic appliances continue to appeal to more patients, which results in objections to extraction spaces that remain for several months during orthodontic therapy. This has led orthodontists to design temporary pontics that fill extraction sites and that can be reduced as the spaces close. This report describes a simple, efficient, and expeditious technique for making such pontics.

Electromyographic evaluation of the upper lip according to the breathing mode: a longitudinal study.

The present study aimed at analyzing and comparing longitudinally the EMG (electromyographic activity) of the superior orbicularis oris muscle according to the breathing mode. The sample, 38 adolescents with Angle Class II Division 1 malocclusion with predominantly nose (PNB) or mouth (PMB) breathing, was evaluated at two different periods, with a two-year interval between them. For that purpose, a 16channel electromyography machine was employed, which was properly calibrated in a PC equipped with an analogue-digital converter, with utilization of surface, passive and bipolar electrodes.

Skeletal and dental components of Class II correction with the bionator and removable headgear splint appliances.

Introduction: The purpose of this study was to differentiate the dentoalveolar and skeletal effects to better understand orthodontic treatment. We evaluated the treatment changes associated with the bionator and the removable headgear splint (RHS).

Methods: The sample comprised 51 consecutively treated Class II patients from 1 office who had all been successfully treated with either a bionator (n=17) or an RHS appliance (n=17).