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OBJECTIVES: The present study aims to compare the drilling protocol effect on osseointegration event in three commercially available titanium dental implants with different drill protocol using a rabbit tibia model. MATERIALS AND METHODS: Three different drilling sequences were compared as follows: drilling sequence using a single unique drill of 4.2 mm conical implant (Group 1), drilling sequence using 3 consecutive cylindrical drills for a 4.1 mm cylindrical implant (Group 2), and drilling sequence using 3 consecutive conical drills for a 4.3 mm conical implant (Group 3). For each group, 18 drilling procedures and implant placements were performed, totalizing 54 commercially available titanium dental implants. The samples were removed 6 weeks after implantation. Resonance frequency analyses (RFA) were performed immediately after the implantation, and at 6 weeks removal torque test (RTt) and histological analysis were performed. RESULTS: The RFA measured showed statistical difference between the groups in time 1 and no significant statistical differences in time 2 (p > 0.05). In the RTt no significant difference was found between the 3 groups tested. Histomorphometric analysis showed no significant difference between groups in the bone-to-implant contact% (p > 0.05). CONCLUSION: In the present preclinical study, osteotomy using a single bur did not show differences regarding the proposed and evaluated tests parameters for assessing the peri-implant behavior.

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Objetivos: avaliar in vivo (histomorfometricamente) o potencial de osseointegração de três marcas comerciais de implantes consideradas como de primeira linha no mercado mundial. Material e métodos: seis coelhos New Zealand, de mesmo peso e idade, receberam 24 implantes de diâmetros similares e comprimentos iguais, de três marcas com tratamentos de superfície variados: G1 (Nobel Biocare, Nobel Replace), G2 (MIS, V3) e G3 (Straumann, Bone Level). Os implantes foram colocados nas metáfises proximais e distais seguindo os protocolos de osteotomia. Após anestesia e sacrífi co dos animais, os implantes foram retirados 45 dias depois para análise histomorfométrica. Ainda, um implante de cada marca foi submetido à análise por MEV (Philips XL30) com diferentes aumentos, sendo as imagens obtidas no modo BSEs. A porcentagem de contato osso-implante entre os grupos foi analisada pelo teste Anova (α=0,05). Resultados: os três modelos de tratamento superficial produziram alta osteocondutividade e boa formação óssea, não havendo diferença entre os valores BIC (p=0,94). Conclusão: as três superfícies testadas apresentaram um grau de osseointegração muito similar.

Objectives: to evaluate by histomorphometrical methods (in vivo) the osseointegration potential of three different implant brands in the world market. Material and methods: six New Zealand rabbits of similar weight and age received 24 dental implants of similar diameters and same length, with three different implant surfaces G1 (Nobel Biocare, Nobel Replace), G2 (MIS, V3), e G3 (Straumann, Bone Level). The implants were installed at the proximal mesial and distal surfaces according the recommend osteotomies. After anesthesia and sacrifice, the implants were retrieved 45 days later for histomorphometrical analysis. Also, one implant from each company was evaluated under SEM BSE mode. The BIC percentage among groups was compared by statistical analysis (One-way ANOVA, 5% level of significance). Results: all three different implant surfaces provided high osteoconductivity and good bone formation, with no significant differences (p=0.94). Conclusion: similar osseointegration patterns were verified among the three tested implant brands.

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OBJECTIVE: This study aimed to measure the influence of drill length and irrigation system on heat production during osteotomy preparation for dental implants using bovine bone rib as experimental model. MATERIALS AND METHODS: Three groups were created: Group 1: drilling with three consecutive burs with double irrigation (internal and external) for a 4.0 mm conical implant; and Group 2 and Group 3: drilling with three consecutive burs with external irrigation for a 4.1 mm cylindrical implant and for a 4.3 mm conical implant, respectively. Four lengths were tested: 10, 12, 14 and 16 mm; in site prepared on bovine ribs using a surgical unit linked to a testing device, to standardize and simulate implant drilling procedures. Bone temperature variations were recorded using three thermocouples in different positions as of the crestal bone: 2 mm, position (p1); 7 mm, position 2 (p2); and 12 mm, position 3 (p3). RESULTS: The highest temperature changes were invariably recorded during the process of withdrawal. Significantly lower temperature changes (P < 0.02) could be recorded at maximum drilling depths during the shearing process regardless of drilling depth or irrigation method. Double irrigation was associated with significantly lower temperatures compared with external irrigation by the use of implant drills (P < 0.01). CONCLUSIONS: Within the limitations of this ex vivo study was possible concluded that the use a double irrigation system in multiple conventional drill for osteotomy can decrease the heat generation when increase the drill length.

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The aim of this study was to evaluate the potential use of a DNA comet assay, DNA fragmentation fluorimetric assay and reactive oxygen species levels as potential biomarkers of genome conditions of dental pulp stem cells (DPSCs) isolated from dog canine teeth. Mesenchymal stem cells were isolated from the dental pulp collected from dog teeth. The results obtained suggest the ideal moment for clinical application of cellular therapy for this type of cell. The cell culture was maintained with Dulbecco's modified Eagle's medium supplemented with 10.00% fetal bovine serum for eight passages. During each passage, cell proliferation, oxidative stress and level of DNA fragmentation were assessed by3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium (MTT) assay, testing 2,7 dichlorodihydro-fluorescein-diacetate and PicoGreen®, respectively. There were important differences among the first three DPSC passages compared to passages 4-8 and a large number of nuclei with some levels of DNA damage (30.00 to 40.00% in initial DPSC passages and > 50.00% in late passages), indicating in vitro DPSC genomic fragility. Within the limitations of this study, the results suggest these relatively simple and inexpensive approaches - comet and DNA fragmentation assays - could help sort stem cells with less DNA damage for use in research or therapies.

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The fit of the implant-abutment interface was assessed by the metallographic technique and by scanning electron microscopy (SEM), using solid abutment types at different torque levels. Forty Morse taper connections and forty solid abutments were used at different torque levels (repeated after 10 minutes) in the following groups (n = 10): 25 Ncm (group g1), 30 Ncm (group g2), 35 Ncm (group g3), and 40 Ncm (group g4). The samples were embedded in a metallographic resin, sectioned lengthwise, and polished. SEM images were used to measure the linear contacts and the fits between abutments and the internal walls of the implant. The overall mean gap and standard deviation were as follows: 9.0 ± 1.36 µm for group g1, 7.9 ± 2.81 µm for group g2, 2.0 ± 0.76 µm for group g3, and 0.3 ± 0.40 µm for group g4. A significant difference was observed in the average fit values between the groups (p < 0.05). The linear area of contact between the abutment and the implant increased as torque augmented. This study demonstrated that higher insertion torque values in a conical internal connection increase the fit (contact) of the implant-abutment interface.

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Abstract The fit of the implant-abutment interface was assessed by the metallographic technique and by scanning electron microscopy (SEM), using solid abutment types at different torque levels. Forty Morse taper connections and forty solid abutments were used at different torque levels (repeated after 10 minutes) in the following groups (n = 10): 25 Ncm (group g1), 30 Ncm (group g2), 35 Ncm (group g3), and 40 Ncm (group g4). The samples were embedded in a metallographic resin, sectioned lengthwise, and polished. SEM images were used to measure the linear contacts and the fits between abutments and the internal walls of the implant. The overall mean gap and standard deviation were as follows: 9.0 ± 1.36 µm for group g1, 7.9 ± 2.81 µm for group g2, 2.0 ± 0.76 µm for group g3, and 0.3 ± 0.40 µm for group g4. A significant difference was observed in the average fit values between the groups (p < 0.05). The linear area of contact between the abutment and the implant increased as torque augmented. This study demonstrated that higher insertion torque values in a conical internal connection increase the fit (contact) of the implant-abutment interface.

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El tejido adiposo es una fuente alternativa de células madre mesenquimales, se presenta como el número de aumento de la colección de células menos invasiva y permitiendo comparación con el método de la médula ósea (MO). En los seres humanos, el metabolismo del tejido adiposo difiere de acuerdo con la localización anatómica. En ratones, se observaron diferencias en la composición celular y la capacidad de diferenciación de las células madre mesenquimales derivadas de tejido adiposo (ADSC), de acuerdo a las regiones anatómicas. El objetivo de este estudio es comparar la proliferación y la viabilidad de las células mesenquimales estromales multipotentes (CTMs) derivados de la bolsa de grasa interescapular, el epiplón mayor y la grasa perirrenal de conejos. Para esto, tres conejos fueron sometidos a cirugía para la extirpación de un tejido adiposo omental, perirrenal y interescapular abultada bolsa. Las células se procesaron y se cultivaron en una atmósfera humidificada con 5% de CO2, y posteriormente se tiñeron con azul de tripano y se contaron en una cámara de Neubauer. Llegamos a la conclusión de que hubo una variación en la capacidad proliferativa de CTMs con respecto a las regiones estudiadas, con la ventaja de la grasa omental en las otras dos regiones. La viabilidad de CTMs las tres regiones mostró variación durante los pasajes.(AU)

Adipose tissue is an alternative source of mesenchymal stem cell. It can be obtained by less invasive method and in larger quantities when compared with bone marrow. In humans, adipose tissue metabolism differs according to anatomic location. In mices, according to the anatomical regions, differences were observed in cellular composition and differentiation capacity of adipose-derived stromal cells (ADSCs). The objective of this study is to compare the viability and proliferation of mesenchymal stromal cells (MSC) derived from the bag interscapular fat, omental and perirenal fats of rabbits. For this, three rabbits were undergone to surgical collect fat from difference sites. Cells were processed and grown in a humidified atmosphere containing 5% CO2, and subsequently they were stained with Trypan blue and counted in a Neubauer chamber. It was concluded that there was variation in the proliferative capacity of MSCs over the regions studied, with advantage of great omental fat about the other regions. The viability of MSCs from the three regions showed variation during passages.(AU)

O tecido adiposo é fonte alternativa de células-tronco mesenquimais, apresentando-se como método menos invasivo e permitindo coleta de maior quantidade celular em comparação a medula óssea (MO). Nos humanos, o tecido adiposo apresenta diferenças de metabolismo, conforme a localização anatômica. Em camundongos, foram observadas diferenças em relação à composição celular e à capacidade de diferenciação das células tronco mesenquimais derivadas do tecido adiposo (ADSCs), de acordo com as regiões anatômicas. O objetivo deste trabalho é comparar a proliferação e viabilidade de células-tronco mesenquimais (CTMs) derivadas da bolsa adiposa interescapular, do omento maior e da gordura da região perirrenal de coelhos. Para isso, três coelhos foram submetidos a procedimentos cirúrgicos para remoção de tecido adiposo do omento maior, região perirrenal e bolsa adiposa interescapular. As células foram processadas e cultivadas em atmosfera umidificada a CO2 5%, sendo posteriormente coradas com Azul de Tripan e contadas em câmara de Neubauer. Concluí-se que houve variação na capacidade proliferativa das CTMs em relação as regiões estudadas, com vantagem da gordura omental sobre as outras duas regiões. A viabilidade das CTMs das três regiões apresentou variação durante as passagens.(AU)

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A astenia cutânea é um raro distúrbio congênito e hereditário que acomete os cães, entre outras espécies,se caracterizando principalmente pelo desarranjo das fibras de colágeno, provocando hiperextensibilidade da pele, fragilidade cutânea e problemas como o afrouxamento articular. O objetivo do presente artigo é relatar um caso de astenia cutânea em uma cadela Poodle toy associada à hérnia perineal, luxação patelar e eventração. Uma cadela Poodle toy foi atendida durante cinco anos e neste período apresentou histórico de luxação patelar medial bilateral, eventrações espontâneas e hérnia perineal. Após a correção cirúrgica de uma das eventrações, enviou-se fragmento cutâneo para estudo histopatológico, no qual foi confirmada astenia cutânea.AU

The cutaneous asthenia is a rare congenital and hereditary disorder that affects dogs, among other species,are mainly characterized by the breakdown of collagen fibers, causing hyperextensible skin, skin fragility and problems such as loosening joints. The purpose of this paper is to report a case of cutaneous asthenia in a dog toy Poodle associated with perineal hernia, eventration, and patellar luxation. A toy Poodle dog was treated for five years and during this period had a history of bilateral medial patellar luxation, spontaneous eventration and perineal hernia. After surgical correction of a eventration, skin fragment was sent for histopathological study which was confirmed cutaneous asthenia.AU

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A astenia cutânea é um raro distúrbio congênito e hereditário que acomete os cães, entre outras espécies,se caracterizando principalmente pelo desarranjo das fibras de colágeno, provocando hiperextensibilidade da pele, fragilidade cutânea e problemas como o afrouxamento articular. O objetivo do presente artigo é relatar um caso de astenia cutânea em uma cadela Poodle toy associada à hérnia perineal, luxação patelar e eventração. Uma cadela Poodle toy foi atendida durante cinco anos e neste período apresentou histórico de luxação patelar medial bilateral, eventrações espontâneas e hérnia perineal. Após a correção cirúrgica de uma das eventrações, enviou-se fragmento cutâneo para estudo histopatológico, no qual foi confirmada astenia cutânea.

The cutaneous asthenia is a rare congenital and hereditary disorder that affects dogs, among other species,are mainly characterized by the breakdown of collagen fibers, causing hyperextensible skin, skin fragility and problems such as loosening joints. The purpose of this paper is to report a case of cutaneous asthenia in a dog toy Poodle associated with perineal hernia, eventration, and patellar luxation. A toy Poodle dog was treated for five years and during this period had a history of bilateral medial patellar luxation, spontaneous eventration and perineal hernia. After surgical correction of a eventration, skin fragment was sent for histopathological study which was confirmed cutaneous asthenia.

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