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.

Estudo aleatório e controlado do uso clínico de um primer autocondicionante na colagem de bráquetes ortodônticos / Bond failure rates with a self-etching primer: a randomized controlled trial

O uso de primers autocondicionantes tem sido proposto como uma alternativa para a redução de passos clínicos. O objetivo deste estudo clínico aleatório e controlado foi avaliar a performance de um sistema autocondicionante (Transbond Plus Self-Etching Primer, 3M Unitek - SEP) comparado a um sistema multipasso convencional (Transbond XT, 3M Unitek - TBXT) de colagem ortodôntica, durante um período de 12 meses. Vinte e oito pacientes participaram deste estudo, sendo estes alocados aos grupos SEP ou TBXT de forma aleatória, através de randomização em bloco. Um total de 548 bráquetes metálicos (Micro-Arch, prescrição Alexander, GAC International, Bohemia, NY) foram colados com uso da pasta adesiva Transbond XT (3M Unitek), sendo todos os produtos manuseados de acordo com as recomendações dos fabricantes. Foram totalizados 276 bráquetes no grupo controle e 272 no segundo. Curvas de sobrevivência Kaplan-Meier e o teste log-rank (p<0,05) foram utilizados para comparar o percentual de falhas adesivas para as duas técnicas. Ao final do período foram verificadas trinta e duas falhas adesivas (bráquetes descolados), sendo 19 (6,98%) falhas quando utilizado o primer autocondicionante (SEP) e 13 (4,71%) quando usado o primer convencional (TBXT). Não houve diferença significante entre a sobrevivência dos bráquetes entre os dois grupos avaliados (log-rank test, p=0,311). Quando a influência de gênero do paciente, arco dentário e tipo dentário (anterior ou posterior) foram analisados, somente o tipo dentário foi achado significante. Bráquetes de dentes posteriores apresentaram uma maior probabilidade de falha adesiva que os colados em dentes anteriores (p=0,013) Os autores concluem que o primer autocondicionante pode ser utilizado para colagem direta de bráquetes ortodônticos sem que sua sobrevivência clínica seja afetada

The use of self-etching primers is presented as an alternative to shorten the clinical bonding steps. The purpose of this clinical trial was to evaluate over a 12-month period the performance of a self-etching system (Transbond Plus SEP, 3M Unitek - SEP) compared with a conventional multi-step system (Transbond XT, 3M Unitek - TBXT). Twenty-eight randomly selected patients were included in this study, each being randomly assigned to TBXT or SEP group. A total of 548 brackets were bonded following the manufacturers’ instructions, using Transbond XT adhesive paste. The survival rate of brackets were estimated with Kaplan-Meier analysis. Bracket survival distributions with respect to bonding procedure, tooth location, dental arch and patient gender were compared with log-rank test. The failure rates of the TBXT and SEP group were 4.71 and 6.98 per cent respectively. No significant differences in the survival rate were observed between the bonding procedures (p=0.311). When the tooth location, dental arch and patient gender were analysed, only the tooth location was found to be significant. Posterior brackets were more likely to fail than the anterior brackets (p=0.013). Both systems had low bonding failure rates and can be considered adequate for orthodontic bonding needs

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.

SEM evaluation of a non-rinse conditioner and a self-etching adhesive regarding enamel penetration.

This study evaluated the effect of a non-rinse conditioner (NRC) associated with two adhesive systems, Prime & Bond NT and Prime & Bond 2.1. The study also evaluated a self-etching adhesive, comparing it with the 37% phosphoric acid effects related to the regularity and infiltration depth of adhesives in human tooth enamel via observation using Scanning Electronic Microscopy (SEM). Fifteen third molars were longitudinally sectioned into four parts by means of a mesio-distal cut and facio-lingual cut. All pieces were flattened with silicon carbide paper, randomly separated and divided into five groups where the enamel surfaces were treated with different materials according to the manufacturers' instructions as follows: Group 1-Prime & Bond NT (Dentsply); Group 2-37% phosphoric acid + Prime & Bond NT; Group 3-Non-Rinse Conditioner (Dentsply) + Prime & Bond NT; Group 4-NRC + Prime & Bond 2.1 (Dentsply); Group 5-Prompt L-Pop (3M ESPE). All teeth were covered with Dyract AP (Dentsply). Specimens were decalcified, metalized and the inner portions of Dyract were observed in SEM and evaluated by calibrated examiners to evaluate resin penetration on enamel. Resin penetration was ranked from 0 = no penetration, to 3 = maximum penetration. The Kruskal-Wallis and Mann-Whitney U tests (p<0.05) showed only three statistically homogeneous groups: {1}, {2,3} and {4,5}. The authors concluded that Prime & Bond NT showed the lowest penetration, NRC showed similar effects compared to phosphoric acid when associated with Prime & Bond NT, and concluded that Prompt L-Pop showed similar effects to NRC, which was associated with Prime & Bond 2.1.

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

Efeito de um primer autocondicionante na resistência ao cisalhamento de bráquetes com compósito pré-incorporado / Effect of a self-etching primer on smear bond strength of adhesive precoated brackets

O uso de primers autocondicionantes e de bráquetes com compósito pré-incorporado tem sido apresentado como uma alternativa para a redução de passos clínicos. O propósito deste estudo foi avaliar o efeito de um primer autocondicionante (Transbond Plus Self-Etching Primer - SEP) na resistência ao cisalhamento de bráquetes com compósito pré-incorporado colados in vivo. A amostra consistiu de 92 dentes obtidos de 23 pacientes com indicação prévia de extração de 4 pré-molares. Os dentes foram divididos em 4 grupos, sendo os bráquetes colados pelo mesmo operador, alternando os quadrantes em cada paciente: Grupo 1 (controle) - Ácido fosfórico à 37% + primer (Transbond XT Primer) + compósito (Transbond XT Adhesive Paste) + bráquete convencional; Grupo 2 - Ácido fosfórico à 37% + primer + bráquete com compósito pré-incorporado; Grupo 3 – SEP + compósito + bráquete convencional; Grupo 4 - SEP + bráquete com compósito pré-incorporado. Após 30 dias os pré-molares foram extraídos, sendo submetidos ao teste de resistência ao cisalhamento através da uma Máquina de Ensaios Universal, com velocidade de 0,5mm/min. Os dados obtidos pelos grupos foram analisados com 2-way ANOVA (p<0,05). As forças médias e desvios padrão obtidos foram os seguintes: Grupo 1 = 11,35 (2,36) MPa; Grupo 2 = 9,77 (2,49) MPa; Grupo 3 = 10,89 (2,60) MPa; e Grupo 4 = 10,16 (2,75) MPa. Não foi observada diferença significativa entre o uso do SEP e o de condicionador e primer tradicionais (p = 0,948). De qualquer modo, diferenças significativas na força de adesão foram observadas quando utilizados bráquetes com compósito pré-incorporado (p = 0,032). Pode ser concluído que a combinação do primer autocondicionante com o bráquete com compósito pré-incorporado apresentou valores de força de adesão adequados, sendo promissora para uso clínico.

The use of self-etching primers and precoated brackets are presented as alternatives to shorten the clinical bonding steps. The aim of this study was to evaluate the influence of a self-etching primer - SEP (Transbond Plus SEP, 3M Unitek) on shear bond strength of adhesive uncoated and precoated Victory brackets (3M Unitek). The sample group consisted of 23 patients with 4 premolars each one, equally divided in four different groups according to the bracket and enamel preparation. Brackets were bonded in vivo, by the same operator, using a split mouth random technique: Group 1- 37% Phosphoric acid + primer + composite + conventional Victory bracket; Group 2- 37% Phosphoric acid + primer + precoated Victory bracket; Group 3- SEP + composite + conventional bracket; Group 4- SEP + precoated bracket. After 30 days premolars were extracted for orthodontic reasons, and 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/min. Mean results and standard deviation for the groups were: Group 1 = 11,35 (2,36) MPa; Group 2 = 9,77 (2,49) MPa; Group 3 = 10,89 (2,60) MPa; e Group 4 = 10,16 (2,75) MPa. The groups were compared using 2-way ANOVA. No difference was observed while a conventional etching and primer or self-etching primer was used (p = 0.948). But, it was indicated significant differences in bond strength between uncoated and precoated brackets (p = 0.032). However, it could be concluded that the self etching primer combined with adhesive precoated brackets showed adequate shear bond strength, and may be suitable for clinical use.

Uma análise dos testes in vitro de força de adesão em Ortodontia / An analysis of in vitro bond strength testing in Orthodontics

O objetivo deste estudo foi analisar as metodologias empregadas em testes in vitro de força de adesão em Ortodontia. Foram selecionados nos periódicos American Journal of Orthodontics and Dentofacial Orthopedics e The Angle Orthodontist (do ano de 1993 até 2002) todos os artigos onde foi avaliada a resistência de adesão de braquetes a diferentes superfícies, através de Máquinas de Ensaio Universal Instron ou similares. Foram analisados 127 artigos, e destes 86 por cento foram conduzidos através de ensaios de cisalhamento, ao passo que 14 por cento foram através de ensaios de tração. Dentre os estudos com dentes humanos (68 por cento), os pré-molares foram os mais utilizados (57 por cento), seguidos pelos molares (31 por cento). Quanto ao número de espécimes por grupo, 28 estudos analisaram entre 6 e 10; 30 entre 11 e 15; 33 entre 16 e 20; e 36 analisaram mais de 20 espécimes. Como solução de armazenamento, as mais empregadas foram: água destilada (43 por cento), seguido de Timol a 0,1 por cento (28 por cento) e Cloreto de sódio a 0,9 por cento (12 por cento). No que diz respeito à velocidade de operação da máquina, em 25 estudos foi de 0,5 mm/min; em 43 foi de 1,0 mm/min; em 8 foi de 2,0 mm/min; e em 38 foi de 5,0 mm/min. Os autores concluem que não existe um consenso na metodologia de tais estudos, sendo então evidenciada a necessidade de uma possível padronização da técnica

Malformações congênitas que afetam o desenvolvimento da face e dos dentes / Congenital malformations affecting facial and teeth development

As deformidades congênitas faciais são resultantes de variações no processo de desenvolvimento normal. Algumas dessas anomalias podem ser traçadas precocemente no primeiro e segundo estágios de desenvolvimento, segundo a classificação de Proffit. Porém, a maioria dos defeitos que resultam em anomalias craniofaciais surge a partir do terceiro estágio, sendo as fendas de lábio e palato os mais comuns. Apesar de nenhuma medida poder ser tomada para diminuir a ocorrência dessas deformidades, o entendimento do desenvolvimento dentário, bem como dos conceitos gerais relacionados ao crescimento e desenvolvimento da face humana é de fundamental importância para que tanto o planejamento como a execução de um tratamento reabilitador sejam realizados satisfatoriamente. Este trabalho visa a apresentação de algumas dessas anomalias resultantes de falhas ocorridas durante o desenvolvimento craniofacial, visto que o seu conhecimento é de grande importância para os profissionais da área odontológica

Comparative SEM evaluation of penetration of adhesive systems in human dentin with a non-rinse conditioner and a self-etching primer

O objetivo desse estudo foi comparar o efeito de um adesivo autocondicionante e de um ácido não lavável quanto a profundidade de penetração na dentina de dentes humanos, através da observação em Microscopia Eletrônica de Varredura (MEV). Quinze terceiros molares tiveram a dentina exposta, cortando-se a face oclusal, planificados com lixa d'água 600, cortados transversalmente e distribuídos em 6 grupos de 5 cada: grupo 1 - Prime Bond NT (NT), controle negativo; grupo 2 - ácido fosfórico 37% + Prime Bond NT (PANT), controle positivo; grupo 3 - Non-Rinse Conditioner (NRC) + Prime Bond NT (NRCNT); grupo 4 - NRC + Prime Bond 2.1 (NRCPB); grupo 5 - NRC + Scotch Bond MP (NRCSB) e grupo 6 - Prompt L-Pop (PLP). Todos foram recobertos com Dyract AP. Os fragmentos dentários foram descalcificados com HCl a 10% e NaOH a 5% e as réplicas em resina examinadas em MEV. Três examinadores calibrados avaliaram as fotomicrografias e atribuíram escores de 0 = sem penetração a 3 = penetração máxima. Os testes de Kruskal-Wallis e Mann-Whitney (P<0,05) evidenciaram três grupos homogêneos {NT, NRCPB, NRCSB e PLP}; {NRCNT} e {PANT}. Os autores concluíram que o sistema adesivo autocondicionante e o ácido não lavável apresentaram menor penetração em dentina do que o sistema adesivo convencional.

Avaliação da infiltração marginal em restaurações calsse V de ormocer / Marginal leakage evalution of class V ormocer restorations

O proposito deste estudo foi comparar a capacidade de selamento marginal do Ormocer e de um sistema adesivo com matriz de Ormocer, com um sistema adesivo e resina composta tradicionais. Foram preparadas duas cavidades classe V padronizadas em 20 dentes hígidos, recém extraídos, localizadas nas faces vestibular e lingual, com uma margem em esmalte e outra em cemento. Os dentes foram divididos aleatoriamente em 4 grupos de 10 cavidades cada: G1, Definite MultiBonde (Degussa-Hüls) + Definite (Degussa-Hüls); G2, Definite MultiBond + TPHSpectrum (Dentsply/DeTrey); G3, Prime & Bond 2.1 (Dentsply/DeTrey) + Definite; G4, Prime & Bond 2.1 + TPH Spectrum (grupo controle). Todas as cavidades foram condicionadas com ácido fosfórico a 37 por cento. Os espécimes foram impermeabilizados, imersos em solução de nitrato de prata a 50 por cento por 24 h, e seccionados. A microinfiltração foi analisada com uma escala de 0-3. A análise estatística revelou diferença significante entre os grupos para microinfiltração tanto em esmalte como em dentina. Os materiais testados neste estudo não foram efetivos em selar completamente as margens gengivais das restaurações

Enhanced interictal responsiveness of the migraineous visual cortex to incongruent bar stimulation: a functional MRI visual activation study.

Since visual aura is usually described as expanding zigzag lines, neurones involved with the perception of line orientation may initiate this phenomenon. A visual incongruent line stimulation protocol was developed to obtain functional magnetic resonance images (fMRI) interictally in 5 female migraine patients with typical fortification spectra and in 5 normal matched controls. Activation in the visual cortex was present contralateral to the side of stimulation in 4 of 5 patients, notably in the extrastriate visual cortex. In 4 of 5 controls activation was observed in the medial and anterior orbitofrontal cortex. In one of them additional activation at the right nucleus accumbens/ventral striatum and right ventral pallidum was present. In the remaining control subject activation was present in the left primary visual cortex. The enhanced interictal reactivity of the visual cortex in migraineurs supports the hypothesis of abnormal cortical excitability as an important pathophysiological mechanism in migraine aura, though the role of specific regions of the visual cortex remains to be explored.

Diastemas interincisais superiores associados a dentes supranumerários: consideraçöes clínicas e relato de um caso / Upper anterior diastema associated with supernumerary teeth: clinical considerations and a case report

Dentes supranumerários na linha mediana superior costumam estar relacionados a problemas estéticos, bem como a complicaçöes patológicas, que podem ser difíceis de solucionar. Neste trabalho os autores se propöem a apresentar um caso clínico de diastema interincisal superior, associado à presença de dois dentes supranumerários, num menino de 8 anos de idade, fazendo consideraçöes clínicas sobre o diagnóstico, o tratamento cirúrgico-ortodôntico e a contençäo desta má-oclusäo