In Vivo Biological Evaluation of Orthodontically Moved Incisors after Replantation.

Background and Objectives: There is still considerable controversy regarding the possibility of submitting replanted teeth to orthodontic movement (OM). The purpose of the present study was to evaluate the tissue response after orthodontic movement on replanted teeth. Materials and Methods: Sixty Wistar rats were randomly assigned to four groups (n = 15): G1, replantation without OM after 30 days; G2, replantation with OM after 30 days; G3, replantation without OM after 60 days, and G4, replantation with OM after 60 days. The maxillary left central incisors were extracted and the teeth were stored in milk media. After 30 min, the teeth were replanted and fixed with non-rigid immobilization. All specimens were observed after 30 and 60 days of replantation and then subdivided into two subgroups (with OM or without OM). The animals were euthanized after seven days of the OM started, and the maxillary bone blocks were processed for histological evaluation. Results: The histological results showed periodontal ligament repair in both periods studied without OM; however, ankylosis and root resorption was seen in all orthodontically moved teeth. Conclusions: The orthodontic movement did not favor tissue response in all replanted teeth, regardless of the experimental periods.

Bond failure rates with a self-etching primer: a randomized controlled trial.

INTRODUCTION: The purpose of this clinical trial was to evaluate over a 12-month period the performance of a self-etching system (SEP) (Transbond Plus SEP, 3M Unitek, Monrovia, Calif) compared with a conventional multi-step system (TBXT) (Transbond XT, 3M Unitek). METHODS: Twenty-eight randomly selected patients were included in this study. They were randomly assigned to either the TBXT or the SEP group. A total of 548 brackets were bonded according to the manufacturer's instructions with Transbond XT adhesive paste (3M Unitek). The survival rates of brackets were estimated with the Kaplan-Meier analysis. Bracket survival distributions for bonding procedure, tooth location, dental arch, and patient sex were compared with the log-rank test. RESULTS: The failure rates of the TBXT and SEP groups were 4.78% and 6.88%, respectively. No significant differences in the survival rates were observed between the bonding procedures (P = 0.311). When tooth location, dental arch, and sex were analyzed, only tooth location was significant. Posterior brackets were more likely to fail than anterior brackets (P = 0.013). CONCLUSIONS: Both systems had low bond failure rates and are adequate for orthodontic bonding needs.

Force-deflection properties of initial orthodontic archwires.

AIM: This in vitro study measured the force-deflection behavior of selected initial alignment archwires by conducting three-point bending tests under controlled conditions. The study tested four wire designs: multistranded stainless steel, conventional stainless steel, superelastic nickel-titanium, and thermoactivated nickel-titanium archwires. METHOD: The wires (n = 15) were ligated into stainless steel brackets with steel ligatures. A testing machine recorded deactivations at 2.0 mm of deflection at 37 degrees C. Force-deflection measurements were recorded from only deactivation. Forces on deactivation were compared by one-way analysis of variance (ANOVA) and Tukey post-hoc tests. RESULTS: Significant differences (P < .05) in deactivation forces were observed among the tested wires. The multistranded stainless steel wire had the lowest mean deactivation force (1.94 N), while the conventional stainless steel group had the highest value (4.70 N). The superelastic and thermoactivated Ni-Ti groups were similar to the multistranded wire (P > .05). CONCLUSION: Both nickel-titanium and multistranded steel archwires tested are potentially adequate for use during the leveling and aligning phase of orthodontics.

Effect of high-intensity LED units at reduced curing time on in vitro bond strength of orthodontic brackets.

AIM: To compare the shear bond strength of stainless steel brackets obtained by 3 high-intensive light-emitting diode (LED) units with conventional halogen polymerization. METHODS: A standard light-curing adhesive paste was used to bond brackets using different lamps and curing times. Eighty permanent bovine incisors were obtained and randomly divided into 4 groups. The first group was bonded using a high-output halogen lamp for 20 seconds, which served as a positive control. The other 3 groups were bonded with high-intensive LED curing devices for 10 seconds. After 30 minutes, a universal testing machine was used to apply an occlusal shear force directly to the enamel-bracket interface at a speed of 0.5 mm/minute. The groups were compared using Kruskal-Wallis test. RESULTS: Mean results and standard deviations for the groups were: group 1 = 11.22 MPa (1.68), group 2 = 10.35 MPa (1.92), group 3 = 11.19 MPa (2.62), and group 4 = 11.82 MPa (2.09). No significant difference was observed in the bond strengths of the 4 groups evaluated (P = . 176). CONCLUSIONS: Under the conditions of the present study, the high-intensity LED units with reduced light-curing time bonded brackets to etched tooth enamel as well as the halogen-based light-curing units.

Surgical correction of a Class II skeletal malocclusion associated with anterior open bite and temporomandibular joint pain.

This case report describes the treatment of a 25-year-old woman with anterior open bite, Class II skeletal malocclusion, and a history of temporomandibular joint pain and sounds. She also had significant anteroposterior and vertical discrepancies and a convex profile with protrusive lips. Intraorally, she had an anterior open bite of 3 mm and an overjet of 5 mm. Mandibular surgical rotation, associated with mandibular incisor extraction, was performed to reduce the protrusion, close the open bite, and minimize the temporomandibular joint disorder.

Effect of enamel etching on tensile bond strength of brackets bonded in vivo with a resin-reinforced glass ionomer cement.

OBJECTIVE: To evaluate the influence of enamel etching on tensile bond strength of orthodontic brackets bonded with resin-reinforced glass ionomer cement. MATERIALS AND METHODS: The sample group consisted of 15 patients who had indications for extraction of four premolars for orthodontic reasons, equally divided into two different groups according to bracket and enamel preparation. Brackets were bonded in vivo, by the same operator, using a split mouth random technique: Group 1 (control), phosphoric acid + Fuji Ortho LC; Group 2, Fuji Ortho LC without acid conditioning. The teeth were extracted after 4 weeks using elevators. An Instron Universal Testing Machine was used to apply a tensile force directly to the enamel-bracket interface at a speed of 0.5 mm/min. The groups were compared using a Mann-Whitney U-test and Weibull analysis. RESULTS: Mean results and standard deviations (in MPa) for the groups were: Group 1, 6.26 (3.21), Group 2, 6.52 (2.73). No significant difference was observed in the bond strengths of the two groups evaluated (P = .599). CONCLUSIONS: Fuji Ortho LC showed adequate shear bond strength and may be suitable for clinical use.

Severe anterior open-bite malocclusion.

This case report describes the treatment of a severe anterior open bite, Class II malocclusion with a history of dummy sucking. The 9-year-old girl presented with a significant anteroposterior and vertical discrepancy. Her face was convex with procumbent lips. She had an anterior open bite of 9 mm, an overjet of 8 mm, and a transverse maxillary deficiency. In consultation with the parents and patient, a nonsurgical therapy was elected, with the goals of reducing protrusion and closing the anterior open bite.

Evaluation of a new self-etching primer on bracket bond strength in vitro.

The purpose of this in vitro study was to evaluate the influence of a new self-etching primer (Adper Prompt L-pop; 3M ESPE, St Paul, Minn) on shear bond strength of orthodontic brackets. Forty extracted human premolars were obtained and randomly divided into two groups of 20 each: group 1 (control), phosphoric acid + Transbond XT primer (3M Unitek, Monróvia, Calif) and group 2, Adper Prompt L-pop. Transbond XT adhesive paste (3M Unitek) was used in both groups for bracket bonding. All products were used according to the manufacturer's instructions. Instron Universal Testing Machine was used to apply an occlusal shear force directly onto the enamel-bracket interface at a speed of 0.5 mm/min. The groups were compared using Student's t-test. Mean results and standard deviation for the groups were: group 1 = 16.23 MPa (4.77), group 2 = 13.56 MPa (4.31). No significant difference was observed in the bond strengths of the two groups evaluated (P = .069). However, the adhesive remnant index was significantly less when conditioning the enamel with Adper Prompt L-pop compared with phosphoric acid (P = .0003). The results suggest no difference in bond strength whether a conventional etching and primer or Adper Prompt L-pop is used. The amount of adhesive on the enamel after debonding was significantly less when using Adper Prompt than when using phosphoric acid. These results indicated that Adper Prompt is potentially adequate for orthodontic bonding needs.

A técnica do arco reto em ortodontia lingual com o uso do PW-MBP / Straight-wire concepts in lingual orthodontics by using PW-MBP

A Ortodontia Lingual representa uma importante opção para tratamento de pacientes adultos. Apesar de todos os avanços concernentes a braquetes e fios, bons resultados dificilmente são obtidos sem um criterioso posicionamento dos braquetes. Um dos recursos disponíveis para montagem é o "Plain Wire Mushroom Bracket Positioner" (PW-MBP), que permite o uso de arcos parabólicos durante o tratamento, eliminando a necessidade de dobras entre os caninos e pré-molares