Fernando Habib

Laser-Induced Alveolar Bone Changes During Orthodontic Movement: A Histological Study on Rodents

OBJECTIVE The aim of this study was to assess by light microscopy changes in alveolar bone during orthodontic movement in rats. BACKGROUND Orthodontic movement causes both removal and deposition of bone tissue. The use of laser phototherapy (LPT) is considered an enhancement factor for bone repair. METHODS Thirty Wistar rats were divided into two groups (n = 15) and subdivided according to animal death (7,13, and 19 days). Half of the animals in each group were treated with LPT during orthodontic movement. After animal death, specimens were processed and underwent histological and semi-quantitative analyses (HE and Sirius red). RESULTS LPT-irradiated specimens showed significantly higher numbers of osteoclasts when compared with controls at both 7 (p = 0.015) and 19 (p = 0.007) days, as well as significant increases in the number of osteoblasts (p = 0.015) between days 7 and 13. The amount of collagen matrix was significantly reduced between days 7 and 13 at both pressure and tension sites in controls (p = 0.015) but not in LPT-treated animals. LPT-treated subjects showed significantly greater deposition of collagen matrix at the pressure site at both the thirteenth (p = 0.007) and nineteenth days (p = 0.001). At the tension site, a significant increase in the amount of collagen matrix was observed in non-irradiated specimens (p = 0.048) between days 7 and 19. CONCLUSIONS LPT caused significant histological changes in the alveolar bone during induced tooth movement, including alterations in the number of both osteoclasts and osteoblasts and in collagen deposition in both pressure and tension areas.

Tooth Movement After Infrared Laser Phototherapy: Clinical Study in Rodents

OBJECTIVES The aim of this research was to investigate the influence of low-power laser on tooth movement in rats. BACKGROUND Tooth movement is closely related to the process of bone remodeling. The biologic result, with the application of a force to the tooth, is bone absorption on the pressure side and neoformation on the traction side of the alveolar bone. The laser photobiomodulation is capable of providing an increase in cellular metabolism, blood flow, and lymphatic drainage. METHODS Thirty young-adult male Wistar rats weighing between 250 and 300 g were divided into two groups, control and experimental, containing 15 animals each. The animals received orthodontic devices calibrated to release a force of 40 g/F, with the purpose of moving the first upper molar mesially. Low-intensity laser, wavelength 790 nm, was used in the experimental group; the dose was 4.5 J/cm(2) per point, mesial and distal, on the palatal side, 11 J/cm(2) on the buccal side, and this procedure was repeated every 48 h, totaling nine applications. The active movement was clinically evaluated after 7, 13, and 19 days. RESULTS AND CONCLUSION The results showed no statistically significant difference, p = 0.079 (T0-T7), p = 0.597 (T7-T13), and p = 0.550 (T13-T19) between the laser and control groups on the amount of tooth movement in the different times evaluated. It may be concluded that laser phototherapy, with the parameters in the present study, did not significantly increase the amount of tooth displacement during induced orthodontic movement in rodents.

Effect of Laser Phototherapy on the Hyalinization Following Orthodontic Tooth Movement in Rats

OBJECTIVE We aimed to assess histologic changes after the use of laser phototherapy (LPT) during induced tooth movement with 40 g/F on young adult male rats. BACKGROUND DATA Hyalinization is a sterile necrosis at the pressure zone of the periodontal ligament observed during the initial stages of the orthodontic movement, and extensive hyaline areas might cause an important delay in the tooth movement. The use of LPT is considered an enhancement factor for bone repair, as it stimulates microcirculation as well as the cellular metabolism. MATERIALS AND METHODS Thirty animals were divided into two groups (n=15), named according to the time of animal death (7, 13, and 19 days). Half of the animals in each group were subjected to irradiation with infrared (IR) laser (λ790 nm, round shaped beam, 40 mW, continuous wave (CW), diameter=2 mm (0.0314 cm(2)), 1.273 W/cm(2), time=2×112 sec+1×275 sec (total time 499 sec), 2×142.6/4.48 J+1×350/11 J, 635.2 J/cm(2)/20 J/ session), during orthodontic movement, the other half were used as nonirradiated controls. After animal death, specimens were sectioned, processed, and stained with hematoxylin and eosin (HE) and Sirius Red, and were used for semi-quantitative histologic analysis by light microscopy. Data were statistically analyzed. RESULTS We demonstrated that LPT positively affected an important aspect of dental movement; the hyalinization. In the present study, we found a significant reduced expression of hyalinization after 19 days. On irradiated subjects, hyalinization was increased at day 7 with significant reduction at day 13. CONCLUSIONS It is possible to conclude that the use of laser light caused histologic alterations during the orthodontic movement characterized by increased formation of areas of hyalinization at early stages, and late reduction when compared to nonirradiated animals.

Obtenção de modelos ortodônticos

INTRODUCTION: Plaster cast models are fundamentals in the diagnosis and treatment planning in Orthodontics. The dental arches can be viewed in three dimensions and the models used as legal documentation for the orthodontist. AIM: Therefore, the object of this paper is to describe the technic of trimming and finishing the models.

Tooth-size discrepancy: A comparison between manual and digital methods

Introduction Technological advances in Dentistry have emerged primarily in the area of diagnostic tools. One example is the 3D scanner, which can transform plaster models into three-dimensional digital models. Objective This study aimed to assess the reliability of tooth size-arch length discrepancy analysis measurements performed on three-dimensional digital models, and compare these measurements with those obtained from plaster models. Material and Methods To this end, plaster models of lower dental arches and their corresponding three-dimensional digital models acquired with a 3Shape R700T scanner were used. All of them had lower permanent dentition. Four different tooth size-arch length discrepancy calculations were performed on each model, two of which by manual methods using calipers and brass wire, and two by digital methods using linear measurements and parabolas. Results Data were statistically assessed using Friedman test and no statistically significant differences were found between the two methods (P > 0.05), except for values found by the linear digital method which revealed a slight, non-significant statistical difference. Conclusions Based on the results, it is reasonable to assert that any of these resources used by orthodontists to clinically assess tooth size-arch length discrepancy can be considered reliable.

Estudo comparativo de seis tipos de braquetes ortodônticos quanto à força de adesão

INTRODUCTION: An accurate diagnosis as well as the correct selection of materials, brackets in particular, are important pre-requisites for success in orthodontic therapy. AIM: The aim of this study was to examine the influence of various brackets-base designs on bond strength. METHODS: Six models were evaluated by a test of sheer bond strength: Discovery (Dentaurum) - metallic with laser grooves and 13.12mm2 of base area; Monobloc (Morelli) - metallic one-piece with raised bumps and 10.22mm2 of area; Edgewise Standard (Ortho Organizers) - metallic with MIM (Metal Injection Molding) and 12.02mm2 of area; Illusion Plus (Ortho Organizers) - ceramic with retention ridges and 13.49mm2 of area; Composite (Morelli) - polycarbonate with raised bumps for mechanical retention with 14.68mm2 of area; and Edgewise Standard (Morelli) - metallic with single mesh and 14.31mm2 of area. The brackets were bonded on bovine teeth with Fill Magic Ortodontico (Vigodent) bond agent, for testing. The study was conduced in a universal test machine (EMIC), and the bond strength was recorded at the moment of split by TESC software, 3.01 version; it was calculated in newtons (N) and megapascal (Mpa). RESULTS AND CONCLUSIONS: No statistical difference among tested brackets was found, and the group with the greatest average bond strength was Discovery with 10,12Mpa.

Colagem ortodôntica em esmalte com presença ou ausência de contaminação salivar: é necessário o uso de adesivo auto-condicionante ou de adesivo hidrofílico?

OBJETIVO: o objetivo deste trabalho foi avaliar a resistencia ao cisalhamento da colagem ortodontica de um adesivo hidrofilico (Transbond Moisture-Insensitive Primer, 3M Unitek, Monrovia, California), de um adesivo auto-condicionante (Transbond Self-Etching Primer, 3M Unitek, Monrovia, California), e sem uso de adesivo, em superficies de esmalte secas ou contaminadas por saliva. METODOLOGIA: incisivos bovinos (60) foram divididos em 6 grupos: (1) controle sem contaminacao salivar (sem adesivo), (2) controle com contaminacao salivar (sem adesivo), (3) adesivo auto-condicionante sem contaminacao salivar, (4) adesivo auto-condicionante com contaminacao salivar antes do adesivo, (5) adesivo hidrofilico sem contaminacao salivar e (6) adesivo hidrofilico com contaminacao salivar antes do adesivo. Braquetes metalicos foram colados com composito (Transbond XT, 3M Unitek, Monrovia, California). Apos a colagem, os corpos-de prova foram armazenados a 37±1oC em ambiente umido ate a realizacao do teste de cisalhamento. Diferenca estatistica foi determinada com valor de probabilidade de 0,05 ou menos (p < 0,05). RESULTADOS: em esmalte sem contaminacao foram encontrados resultados semelhantes entre o controle (1) e o adesivo auto-condicionante (3), enquanto o adesivo hidrofilico (5) apresentou maior forca de cisalhamento. Com a contaminacao salivar, uma diferenca significativa foi encontrada entre o grupo controle (2) e o adesivo auto-condicionante (4), no entanto, nenhuma diferenca foi encontrada entre os adesivos auto-condicionante (4) e hidrofilico (6). CONCLUSAO: desta forma, com o controle de umidade, nao e necessario o uso de um adesivo para se atingir uma adesao aceitavel. Em situacoes clinicas onde ha risco de contaminacao salivar, ambos adesivos podem ser usados.

Vertical control in the Class III compensatory treatment

INTRODUCTION Compensatory orthodontic treatment, or simply orthodontic camouflage, consists in an important alternative to orthognathic surgery in the resolution of skeletal discrepancies in adult patients. It is important to point that, to be successfully performed, diagnosis must be detailed, to evaluate, specifically, dental and facial features, as well as the limitations imposed by the magnitude of the discrepancy. The main complaint, patients treatment expectation, periodontal limits, facial pattern and vertical control are some of the items to be explored in the determination of the viability of a compensatory treatment. Hyperdivergent patients who present with a Class III skeletal discrepancy, associated with a vertical facial pattern, with the presence or tendency to anterior open bite, deserve special attention. In these cases, an efficient strategy of vertical control must be planned and executed. OBJECTIVE The present article aims at illustrating the evolution of efficient alternatives of vertical control in hiperdivergent patients, from the use, in the recent past, of extraoral appliances on the lower dental arch (J-hook), until nowadays, with the advent of skeletal anchorage. But for patients with a more balanced facial pattern, the conventional mechanics with Class III intermaxillary elastics, associated to an accentuated curve of Spee in the upper arch and a reverse curve of Spee in the lower arch, and vertical elastics in the anterior region, continues to be an excellent alternative, if there is extreme collaboration in using the elastics.

Effectiveness of CO2 laser in removal of papillary gingival hyperplasia

INTRODUCTION: Laser applications have increased in a variety of dental procedures, especially in surgeries of soft tissues. Radiation is not invasive and is very well tolerated by tissues. CO2 laser acts in small vessels promoting blood coagulation, making it possible to work in a controlled way. Patients undergoing fixed orthodontic therapy often present injuries of gingival hyperplasia, originating esthetical and functional problems. OBJECTIVE: This study aimed at evaluating the CO2 laser effectiveness in removal of hyperplasia lesions in gingival papilla regions of patients with fixed orthodontic appliances. For this, ten patients were chosen and in these 75 teeth with gingival hyperplasia were identified. Measures from the papilla to incisal edge were performed with the use of a digital caliper. Besides that, the individuals were submitted to previous examinations to the surgical procedure with laser: Full blood count, blood coagulation profile and fasting blood glucose. After this, patients were submitted to the surgery for lesion removal, carried out at the Laser Center of FOUFBA, utilizing a CO2 laser machine (Sharplan 20C, Tel Aviv, Israel). RESULTS: It was showed that laser provided a significant increase (p<0,001) in the distance from the papilla to the incisal edge of the teeth, with no tissue contraction, aspects which were maintained for over two months. CONCLUSION: It can be concluded that CO2 laser has proved to be effective in removal of papillary gingival hyperplasia lesions.

An interview with Kotaro Tanimoto

If I had to describe Tanimoto Sensei using a single word I would say kindness. When I was attending the PhD course in Hiroshima University, I frequently looked at him and thought: “If I have the chance to be an educator, I would like to be like that man.” The generosity, respect and friendship he employed to treat the students is fascinating. By that time, Professor Tanimoto had just come back from his post-doc in the USA full of ideas and dreams. Since that, many of the ideas had become projects and many of the projects had become a real benefit for the patients. Tanimoto Sensei has an extensive and relevant scientific production and some of them are described in the next pages. I believe this interview is especially interesting because it is enriching to know how professors from the other side of the globe conduct orthodontic education and science. Finally, I would like to express my sincere gratitude to the other professors that assisted in this article and to Dental Press Journal of Orthodontics for the opportunity to conduct the present interview with Professor Tanimoto, a great friend of mine. Emanuel Braga – interview coordinator » DDS, Hiroshima University, Japan. » PhD in Orthodontics, Hiroshima University, Japan. » Head of Department, Department of Orthodontics, Hiroshima University Institute of Biomedical & Health Sciences, Japan.