Histologic, histomorphometric, and radiographic monitoring of bone healing around in-office-sterilized orthodontic mini-implants with or without immediate load: study in rabbit tibiae.

PURPOSE: The objective of this study was to describe bone healing around self-drilling orthodontic mini-implants (MIs), sterilized in an office with an autoclave, with or without immediate orthodontic loading. MATERIALS AND METHODS: One hundred forty-four self-drilling MIs (TOMAS, Dentaurum) were inserted into the tibiae of 18 white rabbits, with full-thickness flaps elevated under general anesthesia. An immediate load (50 cN) was applied to 50% of the MIs. Two rabbits were sacrificed soon after the surgery and served as a control group. Four rabbits each were sacrificed at 15, 21, 30, or 60 days after the surgeries. Digital radiographs were obtained to measure the cortical bone thickness (CBT) around and between the implants. Sections were obtained and stained for histologic and histomorphometric analysis. Bone quantity (BQ), bone-to-implant contact (BIC), and CBT were evaluated statistically. RESULTS: At day 0, fractures were visible in the cortical area around the MIs. At days 15 and 21, intense proliferation of woven bone followed by formation of lamellar bone was seen. After 30 days, primary bone was visible, with less proliferation activity. At day 60, primary bone in the process of remodeling into secondary bone was apparent. BQ was better with loading after 15 days and increased throughout the healing period in the loaded and unloaded groups. Loading did not influence the BIC values, which increased with healing time for loaded and unloaded implants. CBT increased in all regions, and CBT was greater around the MIs than between them except for unloaded MIs in the 15-day group. CONCLUSION: An immediate, light orthodontic load did not affect the bone healing process around orthodontic MIs. Osseointegration and CBT increased and were time-related.

A comparative clinical study of the failure rate of orthodontic brackets bonded with two adhesive systems: conventional and self-etching primer (SEP)

OBJECTIVE: This study compared the clinical performance of orthodontic brackets bonded with Transbond adhesive paste after two priming systems: a two-stage conventional system (acid etching + Transbond XT adhesive primer) and a singlestage self-etching primer (SEP) (Transbond Plus). METHODS: The sample comprised 480 metal brackets bonded to the teeth of 24 consecutive patients treated for 36 to 48 months. A split-mouth design was used for bonding, and both systems were used in each patient. Bracket failure rates for each system were analyzed; and failure causes as reported by the patients and the quadrant of teeth for which brackets failed were recorded. RESULTS: The conventional system group had a failure rate of 5.41%, whereas the rate for SEP was 4.58%. In this group, there were 5 failures (38.4%) in the right maxillary quadrant, 2 (15.4%) in the left maxillary quadrant, 4 (30.8%) in the right mandibular quadrant, and 2 (15.4%) in the left mandibular quadrant. In the SEP group, there were 4 (36.4%) failures in the right maxillary quadrant, 1 (9%) in the left maxillary quadrant, 3 (27.3%) in the right mandibular quadrant, and 3 (27.3%) in the left mandibular quadrant. Results of descriptive statistical analysis and odds ratio did not show any significant differences between rates (p = 0.67). CONCLUSION: The clinical efficiency of SEP was similar to that of the conventional system.

OBJETIVO: o objetivo do presente estudo foi comparar o desempenho clínico da colagem de braquetes ortodônticos com resina Transbond (3M Unitek) associada a dois sistemas adesivos: convencional em duas etapas (ataque ácido + Transbond XT adhesive Primer) e Self-Etching Primer (SEP), em etapa única (Transbond Plus). MÉTODOS: a amostra foi constituída de 480 braquetes metálicos (Victory, 3M Unitek), colados em 24 pacientes, que foram tratados durante um período de 36 a 48 meses. A colagem foi feita por meio do sistema split-mouth, utilizando os dois sistemas de colagem em cada paciente. Foi analisada a taxa de queda dos braquetes para cada sistema de colagem, descrita a causa da queda conforme relato do paciente e a posição dos dentes nas arcadas. RESULTADOS: o sistema adesivo convencional apresentou taxa de queda de 5,41%, enquanto a do SEP foi de 4,58%. O sistema convencional apresentou 5 quedas (38,4%) no quadrante superior direito, 2 (15,4%) no quadrante superior esquerdo, 4 (30,8%) no quadrante inferior direito e 2 (15,4%) no quadrante inferior esquerdo. O SEP apresentou 4 quedas (36,4%) no quadrante superior direito, 1 (9%) no quadrante superior esquerdo, 3 (27,3%) no quadrante inferior direito e 3 (27,3%) no quadrante inferior esquerdo. Por meio da análise estatística descritiva e do teste Odds Ratio, constatou-se que não houve diferença significativa entre essas taxas (p = 0,67). CONCLUSÃO: com base nesses resultados, pode-se concluir que o sistema adesivo SEP apresentou eficácia clínica semelhante à do sistema adesivo convencional.

Abordagem interdisciplinar em reabilitacão bucal / Interdisciplinary approach in oral rehabilitation

A complexidade do tratamento definirá a necessidade de uma abordagem interdisciplinar para alcançar resultados de sucesso. Quando se associa perdas dentárias, perda do relacionamento oclusal, mau posicionamento dentário, ao descontrole do estado geral da saúde bucal como, por exemplo, a perda de inserção devido à doença periodontal, a decisão da proposta de tratamento merece cuidados e o prognóstico de uma etapa do tratamento depende do su- cesso de outra. Desta forma, no caso a seguir, as disciplinas de Ortodontia do Departamento de Ortodontia e Odontopediatria e de Clínica Integrada do Departamento de Estomatologia da Faculdade de Odontologia da Universidade de São Paulo (Fousp), de maneira interdisciplinar, foram determinantes para o sucesso da reabilitação do paciente. Após a fase de controle da saúde bucal iniciou-se o tratamento ortodôntico fixo em ambas as arcadas. Concluída a movimentação dentária com fechamento dos diastemas e nivelamento oclusal (cerca de 24 meses) e sua manutenção, iniciou-se a fase reabilitadora do tratamento, com um minucioso estudo com a finalidade de apresentar alternativas para o tratamento protético.

The complexity of the treatment will define the necessity of an interdisciplinary approach to achieve successful results. The association between tooth loss, loss of occlusal relationship, bad teeth positioning, with the lack of the general state of oral health such as insertion loss due to periodontal disease, the decision of the proposed treatment deserves care and prognosis of a stage of treatment depends on the success of a nother. Th us, i n the followi ng case, the Orthodontics Department of Orthodontics and Pediatric Dentistry and Integrated Clinic, Department of Stomatology, School of Dentistry, University of São Paulo, in an interdisciplinary way, were crucial to the success of rehabilitation. After the stage of the oral health control began the fixed orthodontic treatment in both arches. Complete tooth movement with diastemas resolution and occlusalleveling (about 24 months) and their maintenance, the rehabilitative phase of treatment started, with a detailed study with the purpose of presenting of prosthetic treatment alternatives.

Como preparar secções histológicas de tecidos não descalcificados com implantes metálicos? Descrição de técnica modificada / How to prepare histological sections of non-decalcified tissue with metal implants? Modified technique

Tendo em vista a falta de detalhamento minucioso na literatura existente, este relato descreve uma metodologia modificada de preparo das amostras de osso contendo implantes metálicos, para análise por microscopia óptica, fluorescência ou polarização. Os fragmentos de osso contendo os implantes são fixados, desidratados e incluídos em resina metilmetacrilato para finalmente serem cortados. As secções obtidas são colocadas em lâminas de acrílico e reduzidas à espessura desejada de 20 a 50 um utilizando de lixas d'água para o desgaste e polimento da superfície. Esta técnica produz lâminas histológicas de excelente qualidade, sem danos à interface osso-implante, e que permite observação detalhada da arquitetura tecidual, dos tipos celulares presentes e dos fluocromos. Stevenels blue contracorada por Alizarina red S31 são colorações descritas que permitem em microscopia óptica diferenciar tipos celulares e teciduais presentes no sítio do implante

Precise insertion of orthodontic miniscrews with a stereolithographic surgical guide based on cone beam computed tomography data: a pilot study.

PURPOSE: Orthodontic miniscrews are commonly used to achieve absolute anchorage during tooth movement. One of the most frequent complications is screw loss as a result of root contact. Increased precision during the process of miniscrew insertion would help prevent screw loss and potential root damage, improving treatment outcomes. Stereolithographic surgical guides have been commonly used for prosthetic implants to increase the precision of insertion. The objective of this paper was to describe the use of a stereolithographic surgical guide suitable for one-component orthodontic miniscrews based on cone beam computed tomography (CBCT) data and to evaluate implant placement accuracy. MATERIALS AND METHODS: Acrylic splints were adapted to the dental arches of four patients, and six radiopaque reference points were filled with gutta-percha. The patients were submitted to CBCT while they wore the occlusal splint. Another series of images was captured with the splint alone. After superimposition and segmentation, miniscrew insertion was simulated using planning software that allowed the user to check the implant position in all planes and in three dimensions. In a rapid-prototyping machine, a stereolithographic guide was fabricated with metallic sleeves located at the insertion points to allow for three-dimensional control of the pilot bur. The surgical guide was worn during surgery. After implant insertion, each patient was submitted to CBCT a second time to verify the implant position and the accuracy of the placement of the miniscrews. RESULTS: The average differences between the planned and inserted positions for the ten miniscrews were 0.86 mm at the coronal end, 0.71 mm at the center, and 0.87 mm at the apical tip. The average angular discrepancy was 1.76 degrees. CONCLUSIONS: The use of stereolithographic surgical guides based on CBCT data allows for accurate orthodontic mini screw insertion without damaging neighboring anatomic structures.

Extrusão dentária com finalidade restauradora / Tooth extrusion for restorative purpose

O objetivo deste trabalho é revisar a literatura sobre o tracionamento dentário para fins restauradores, apresentar considerações biológicas e mecânicas sobre este procedimento e demonstrar através de casos clínicos a aplicabilidade das técnicas.

The objective of this work is to revise the literature about dental traction for restorative purposes, to present biological and mechanical considerations on this procedure and to demonstrate through clinical cases the applicability of the technique.

Formação tardia de pré-molares supranumerários em pacientes ortodônticos / Late formation of supernumerary premolars in orthodontics patients

A presença de pré-molares supranumerários, embora com baixa freqüência, exige a tomada de uma decisão apropriada entre monitorá-los ou removê-los. As características individuais de cada caso devem determinar essa decisão, com base no risco cirúrgico e. no beneficio da remoção. Especificamente em pacientes ortodônticos, a presença de pré-molares supranumerários pode impedir ou atrasar o fechamento de espaços ou eventualmente causar reabsorção das raízes adjacentes. No caso de optar-se por removê-los é necessário o controle radiográfico em longo prazo, considerando que têm sido relatadas recidivas e formações em épocas diferentes em casos de incidências múltiplas. O objetivo no presente trabalho foi revisar a incidência, etiologia, desenvolvimento, localização e tratamento de pré-molares supranumerários descritos na literatura e ilustrar com um caso clínico.

Although with low frequency, the presence of supernumerary bicuspids requires appropriate decision making between their extraction and preservation with monitoring. The individual characteristics that play a key role in each case are based on the surgical risk and on the benefit of tooth removal. The presence of supernumerary bicuspid can avoid or delay orthodontic space closure or, eventually, resorbe the roots of neighboring teeth. In case of 100th removal is also required a long-term radiographic, follow-up having been reported in the literature multiple supernumerary formations at different times of interval. The aims of this paper were a literature review on the incidence, etiology, development, localization and treatment of supernumerary premolars and to report a clinical case.