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OBJECTIVE: The aim of the present in vitro study was to evaluate the resistance on quasi-static forces and in the fatigue mechanical cycling of a new implant design compared to two other conventional implant designs. MATERIALS AND METHODS: Eighty-eight implants with their respective abutments were tested and distributed into four groups (n = 22 per group): Morse taper connection implant (MT group), conventional external hexagon implant (EH con group), new Collo implant of external hexagon with the smooth portion out of the bone insertion (EH out group), and new Collo implant of external hexagon with the implant platform inserted to the bone level (EH bl group). All the sets were subjected to quasi-static loading in a universal testing machine, and we measured the maximum resistance force supported by each sample. Another 12 samples from each group were submitted to the cyclic fatigue test at 4 intensities of forces (n = 3 per force): 80%, 60%, 40%, and 20%. The number of cycles supported by each sample at each force intensity was evaluated. RESULTS: The three groups of implants with external hexagon connection had similar maximum strength values of the sets (p > 0.05). Meanwhile, samples from the MT group showed the highest resistance values in comparison to the other three groups (p < 0.05). In the fatigue test, the Collo out group supported a smaller number of cycles that led to the fracture than the other 3 groups proposed at loads of 80%, 60%, and 40%, and only at the load value of 20% all groups had the same performance. CONCLUSIONS: Within the limitations of the present in vitro study, the results showed that the new Collo implant performs better when installed at bone level.

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A large number of materials with different compositions and shapes have been proposed and studied for the purpose of bone tissue regeneration. Collagen-based materials have shown promising results for this application, with improved physicochemical properties. The aim of the present in vivo animal study was to evaluate and compare two commercially available collagen-based biomaterials for bone regeneration, with these being implanted in circumferential bone defects created in the calvarium of rabbits. Twenty rabbits received bilateral parietal osteotomies, performed with the aid of a 6.5 mm diameter trephine. Two groups were created: the BC group, where the defect was filled with a scaffold composed of 90% bovine bone particles and 10% porcine collagen, and the EG group, where the defect was filled with a scaffold composed of 75% hydroxyapatite particles of bovine origin and 25% bovine collagen. Ten animals were sacrificed at 30 days and another 10 at 45 days after implantation, and the samples were processed and histologically analyzed. In the evaluations of the samples at 30 days, no important differences were found in the results. However, in the samples at 45 days after surgery, the EG group showed better results than the BC group samples, mainly in terms of the amount of bone matrix formation (P < 0.0001) and the volume in area measured in each sample, where the EG group had a value 65% higher than that in the BC group samples. Based on the results obtained, we conclude that the amount of collagen and the particle characteristics present in the composition of the scaffolds can directly influence the amount of neoformation and/or bone regeneration.

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BACKGROUND: During the masticatory cycle, loads of different intensities and directions are received by the dental structures and/or implants, which can cause micromovements at the junction between the abutment and implant. OBJECTIVE: The objective of this in vitro study was to evaluate the behavior of three different implant connections subjected to different load values using a digital radiography system. Additionally, the torque values for removing the abutment screws were also measured and compared. METHODS: Ninety sets of implant and abutment (IA) were used, divided into three groups according to the type of connection (n = 30 per group): EH group, external hexagon type connection; IH group, internal hexagon connection; and, MT group, Morse taper connection. RESULTS: MT group showed the better vertical misfit behavior at the three intensity of load applied, in comparison with EH and IH groups. In the analysis of torque maintenance (detorque test), MT group showed higher values of detorque when compared with the measured values of EH and IH groups (p < 0.001). CONCLUSIONS: The IA sets of EH and IH groups showed a microgap in all levels of applied loads, unlike the MT group this event was not observed. In the detorque test, MT group increase in the torque values when compared to the initial torque applied, unlike EH and IH groups showed a decrease in the initially torque applied in all conditions tested. A positive correlation was detected between the misfit and detorque values.

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Dental implants are not routinely used for rehabilitation in veterinary dentistry. For some veterinarians, further studies are necessary to be considered for clinical use in animals. The objective of the present in vitro study was to evaluate static fatigue of dental implants and to correlate that with the bite strength of dogs described in the literature. Sixty implants and abutments were used with the smallest diameter of each brand of implant utilized in the study. Three groups (n = 20) were created on the basis of the implant diameter, all with external hex connector: 3.30 mm (group 1), 4.0 mm (group 2) and 5.0 mm (group 3). All groups were subjected to quasi-static loading at 30° to the implant's long axis in a universal machine (model AME-5 kN). The mean fracture strength for group 1 was 964 ± 187 N, for group 2 was 1618 ± 149 N and for group 3 was 2595 ± 161 N. Significant differences between the groups with respect to resistance after the load applications were observed (P < .05). The diameter of implants affects the resistance to external forces during the application of non-axial strength (off-axis loading) and must be considered during the planning of rehabilitation to avoid problems.

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BACKGROUND: The ideal installation technique or implant macrogeometry for obtaining an adequate osseointegration in low-density bone tissue follows a challenge in the implantology. AIMS AND OBJECTIVE: The aim of the present study was to evaluate the behavior of three osteotomy techniques and two implant macrogeometries in two low-density polyurethane blocks. The insertion torque (IT), initial stability, pullout resistance, and weight of the residual bone material deposited on the implants were assessed. MATERIALS AND METHODS: A total of 120 implants with two different macrogeometries were used. They were divided into six groups according to the implant macrogeometry and the drilling technique performed (n = 20 implants per group). The implants were installed in polyurethane blocks with pounds per cubic foot (PCF) 10 and PCF 20 densities. The IT, initial stability, pullout resistance, and weight residual bone were measured. RESULTS: Differences were found in the values referring to the macrogeometry of the implants and the type of osteotomy performed. In all groups, the initial stability of the PCF 10 blocks was quite low. The undersized osteotomies significantly increased the values measured in all tests in the PCF 20 density blocks. CONCLUSIONS: In conclusion, even when a modified (undersized) osteotomy technique is used, implants inserted in low-quality bone (type IV) can present problems for osseointegration due their low initial stability and bone resistance. However, the modification in the implant macrogeometry (with healing chambers) presented more quantity of bone on the surface after the pullout test.

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OBJECTIVE: To compare the mechanical strength of joints made by conventional soldering with those made by alternative, more biocompatible, methods (spot, tungsten inert gas [TIG] and laser welding), and to compare the microstructural morphology of wires welded with these techniques. DESIGN: In vitro, laboratory study. METHODS: Forty stainless-steel wire segments with 0.8-mm diameter were joined by silver soldering, spot, laser and TIG welding. Ten specimens were produced for each one. Tensile strength test was performed 24 h after welding on the Emic DL2000™ universal testing machine, using a load cell of 1000 N with a crosshead speed of 10 mm/min. RESULTS: The highest tensile strength mean values were obtained with silver soldering (532 N), next were laser (420 N), spot (301 N) and TIG (296 N) welding. Statistically significant differences were observed between the groups; the Dunn post-hoc test revealed differences between laser and spot welding (p=0.046), laser and TIG (p = 0.016), spot and silver (p <0.001), and silver and TIG (p <0.001). CONCLUSION: Laser welding strength is high, and comparable to silver welding. Spot and TIG techniques present comparable and significantly lower strengths. The four methods presented resistance values compatible with orthodontic use. The microstructural morphology is different for each technique. The association between the mechanical performance and the microstructure evaluation shows that laser presented the highest quality joint.

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The present in vitro study evaluated a new drill design to improve the temperature control during the osteotomies for dental implant installation, comparing with two drill designs that use conventional external irrigation. Three blocks of synthetic cortical bone were used for osteotomy procedures. Three groups were created: control group 1 (Con1), where a conical multiple drill system with a conventional external irrigation system was used; control group 2 (Con2), where a single bur with a conventional external irrigation system was used; and, test group (Test), where the new single bur (turbo drill) with a new irrigation system was used. Twenty osteotomies were made without irrigation and with intense irrigation, for each group. A thermocouple was used to measure the temperature produced during the osteotomies. The measured temperature were: 28.9 ± 1.68 °C for group Con1; 27.5 ± 1.32 °C for group Con2; 26.3 ± 1.28 °C for group Test. Whereas, the measured temperatures with irrigation were: 23.1 ± 1.27 °C for group Con1; 21.7 ± 1.36 °C for group Con2; 19.4 ± 1.29 °C for group Test. The single drill with a new design for improving the irrigation and temperature control, in comparison with the drill designs with conventional external irrigation.

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OBJECTIVES: The propose was to compare this new implant macrogeometry with a control implant with a conventional macrogeometry. MATERIALS AND METHODS: Eighty-six conical implants were divided in two groups (n = 43 per group): group control (group CON) that were used conical implants with a conventional macrogeometry and, group test (group TEST) that were used implants with the new macrogeometry. The new implant macrogeometry show several circular healing cambers between the threads, distributed in the implant body. Three implants of each group were used to scanning electronic microscopy (SEM) analysis and, other eighty samples (n = 40 per group) were inserted the tibia of ten rabbit (n = 2 per tibia), determined by randomization. The animals were sacrificed (n = 5 per time) at 3-weeks (Time 1) and at 4-weeks after the implantations (Time 2). The biomechanical evaluation proposed was the measurement of the implant stability quotient (ISQ) and the removal torque values (RTv). The microscopical analysis was a histomorphometric measurement of the bone to implant contact (%BIC) and the SEM evaluation of the bone adhered on the removed implants. RESULTS: The results showed that the implants of the group TEST produced a significant enhancement in the osseointegration in comparison with the group CON. The ISQ and RTv tests showed superior values for the group TEST in the both measured times (3- and 4-weeks), with significant differences (p < 0.05). More residual bone in quantity and quality was observed in the samples of the group TEST on the surface of the removed implants. Moreover, the %BIC demonstrated an important increasing for the group TEST in both times, with statistical differences (in Time 1 p = 0.0103 and in Time 2 p < 0.0003). CONCLUSIONS: Then, we can conclude that the alterations in the implant macrogeometry promote several benefits on the osseointegration process.

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Background: The objective of the present histologic animal study was to analyze whether roughness of the titanium surface can influence and/or stimulate the bone growth in defects filled with the blood using a rabbit tibia model. Materials and Methods: Forty sets (implant and abutment), dental implant (3.5 mm in diameter and 7 mm in length) plus healing abutment (2.5 mm in diameter), were inserted in the tibiae of 10 rabbits. Moreover, twenty titanium discs were prepared. The abutment and discs were treated by 4 different methods and divided into 4 groups: (group A) machined abutments (smooth); (group B) double acid etching treatment; (group C) treatment with blasting with particles of aluminum oxide blasted plus acid conditioning; (group D) treatment with thorough blasting with particles of titanium oxide plus acid conditioning. The discs were used to characterize the surfaces by a profilometer and scanning electronic microscopy. Results: After 8 weeks, the new bone formation around the sets of the samples was analyzed qualitatively and quantitatively in relation to bone height from the base of the implant and presence of osteocytes. Group C (1.50±0.20 mm) and group D (1.62±0.18 mm) showed bone growth on the abutment with higher values compared to group A (0.94±0.30 mm) and group B (1.19±0.23 mm), with significant difference between the groups (P < 0.05). In addition, osteocyte presence was higher in groups with surface treatment related to machined (P < 0.05). Conclusions: Within the limitations of the present study, it was possible to observe that there is a direct relationship between the roughness present on the titanium surface and the stimulus for bone formation, since the presence of larger amounts of osteocytes on SLA surfaces evidenced this fact. Furthermore, the increased formation of bone tissue in height demonstrates that there is an important difference between the physical and chemical methods used for surface treatment.

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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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BACKGROUND: New manufacturing methods was developed to improve the tissues integration with the titanium alloy pieces. OBJECTIVE: The present in vitro study was to assess the resistance and fracture mode after applied a quasi-static compressive force on the two dental implants manufactured by direct metal laser sintering. MATERIALS AND METHODS: Twenty dental implants manufactured by direct metal laser sintering, using titanium alloy (Ti-6Al-4V) granules in two designs (n = 10 per group): Conventional dental implant (group Imp1) two-piece implant design, where the surgical implant and prosthetic abutment are two separate components and, the one-piece implant (group Imp2), where the surgical implant and prosthetic abutment are one integral piece. All samples were subjected to quasi-static loading at a 30° angle to the implant axis in a universal testing machine. RESULTS: The mean fracture strengths were 1269.2 ± 128.8 N for the group Imp1 and, 1259.5 ± 115.1 N for the group Imp2, without statistical differences (P = .8722). In both groups, the fracture surface does not present crack between the compact core and the superficial (less dense and porous) part of the implants. CONCLUSIONS: Based on the measured resistance data for the two implant models manufactured by direct metal laser sintering tested in the present study, we can suggest that they have adequate capacity to withstand the masticatory loads.

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BACKGROUND: The topographical surficial characteristics and properties of materials can induce different cell reactions regarding the viability and adhesion according to the recent patents. The aim of this in vitro experimental study was to evaluate the viability and adhesion of fibroblastic cells seeded on titanium disks with different surface topography. In addition, we revised all patents related to surface treatment of dental implants. METHODS: Fibroblast cells were cultured on 6 surface models: mA disks corresponding to titanium surfaces without additional treatment (machined surface) were compared with mB disks, where surfaces were sandblasting etching using aluminum oxide; mC disks where titanium oxide was used for sandblasting etching; mD disks where triple acid conditioning was used; mE disks with laser treated surface; and mF disks which were made of titanium powder by a sintering process. Different surfaces were analyzed using an optical laser profilometer and SEM analysis. To evaluate cell viability on different disc surfaces, a fibroblast cell line derived from monkey kidney (VERO) was in vitro cultured on treated disks surface and cell viability assays were performed to compare growth of fibroblastic cells. Then, the adhesion of the cells was tested by washing procedure. RESULTS: The disks mA, mB, mC and mD less pronounced rugosities were observed and, disc in the mE and mF disks displayed a deeper pronounced surface. The cell viability and adhesion analysis showed significant higher levels on titanium disks surface obtained by the mF method. CONCLUSION: Our analysis showed that the surface morphology of titanium disc, independent of the roughness parameters, affects cell viability and adhesion differentially, since a higher percentage of viable and attached cells were observed on the mF disks in comparison with the other evaluated surfaces.

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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 objetivo de este estudio fue la observación in vitro y in vivo de implantes arenados con partículas de TiO. La observación in vitro fue hecha con la obtención de imágenes en MEB y evaluación de las características morfológicas. Para las evaluaciones invivo fueron utilizados seis conejos New Zeland, adultos, con peso medio de 3,5kg obtenidos en el Bioterio de la Universidad Federal de Santa María. Fueron utilizados 24 implantes cilíndricos de hexágono interno fabricados por la empresa ImplacilMaterial odontológico (Implantes DeBortoli), arenados por TiO. Un marcador de crecimiento óseo de fluorescencia, Calceina, fue inyectada subcutáneamente en dos diferentes intervalos de tiempo, para evaluar la cantidad de deposición de calcio en elhueso en los períodos de la segunda a cuarta semana, correspondiendo a el Grupo experimental 1 (exp1) con 3 animales; y de la sexta a octava semana, correspondiendo a el Grupo experimental 2 (exp2) con 3 animales. Las muestras fueron cortadasobteniéndose 3 cortes de cada implante, utilizando uno para cada técnica histológica: microscopía de luz, de fluorescencia y de barrido, donde fueron analizadas y comparadas las áreas de contacto entre hueso/implante en tiempos de 30 y 60 días. Losresultados demostraron que la superficie propuesta promueve una estimulación ósea muy efectiva en los tiempos estudiados. Los implantes presentaron grandes áreas de hueso corticalizado y una característica de hueso lamelar. La deposición de calcioocurre con más intensidad después de los 30 días de la implantación. De esta manera se concluye que la superficie presentada por los implantes DeBortoli arenados por partículas de TiO tienen una buena capacidad óseo-conductora, promoviendo un adecuado crecimiento y corticalización del hueso.

The aim of this study was the observation in vitro and in vivo implants sandblasted with particles of TiO. The in vitro observation was made with imaging in SEM and evaluation of morphological characteristics. Six adult New Zealand rabbits with average weight of 3.5 kg obtained from the Bioterio of the Federal University of Santa Maria were used for in vivo evaluations. Were used 24 cylindrical implants with internal hex manufactured by the company Implacil Dental Material (Implants DeBortoli) sandblasted to TiO. A marker of bone growth of fluorescence, calcein was injected subcutaneously at two different time intervals to assess the calcium deposition in the bone in the period from second to fourth week, corresponding to the experimental group 1 (exp1) with 3 animals, and from sixth to eighth week, corresponding to the experimental group 2 (exp2) with 3 animals. Thesamples obtained were cut 3 slices of each implant using a histological technique for each: light microscopy, fluorescence and scanning, which were analyzed and compared the contact areas between bone/implant times of 30 days and 60 days. The resultsdemonstrate that the proposed surface promotes bone stimulation very effectively in the times studied. Implants of bone presented large areas corticalized and a feature of lamellar bone. Calcium deposition occurs with more intensity after 30 days ofimplantation. Thus we conclude that the implant surface by DeBortoli sandblasted with particles of TiO have good boneconductive capacity, promoting proper growth and bone corticalization.

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Com o objetivo de desenvolver, caracterizar e avaliar uma superfície microtexturizada de implantes propôs-se a realização deste estudo primeiramente laboratorial, através da Microscopia Eletrônica de Varredura (MEV) e microanálise por Energia de Dispersão (EDS) e, em um segundo estágio in vivo em animais. Para isso, foram fornecidos pela empresa Implacil – Materiais Odontológicos (Implantes DeBortoli) 24 implantes cilíndricos, os quais foram divididos em dois grupos: 1 – Implantes jateados por TiO; 2 – Implantes jateados e microtexturizados por imersão em ácido Fluorídrico. Os resultados demonstraram que na primeira fase os implantes avaliados em MEV do grupo 2 tiveram uma morfologia superficial muito mais uniforme e regular que o grupo 1. Na análise por EDS também o grupo 2 apresentou um melhor resultado, não sendo identificado nenhum tipo de contaminante em suas amostras, diferentemente do grupo 1 o qual tivemos a presença de Alumínio. Na segunda fase em que foram utilizados seis coelhos, que receberam 2 implantes em cada tíbia, foi observado o índice de tecido ósseo corticalizado em contato com a superfície, após oito semanas, tivemos um índice médio de 37,10% no grupo 1 e 58,73% no grupo 2. Em conclusão podemos verificar que é possível controlar físico-quimicamente a microtexturização superficialdos implantes e que isso além de dar uma conformação mais uniforme a superfície, elimina a possibilidade de contaminantes, aumentando o índice de osteointegração e formação de tecido ósseo corticalizado.

In order to develop, characterize and to evaluate a microtextured surface implant proposed to achieve this first laboratory study by Scanning Electron Microscopy (SEM) and microanalysis by energy dispersion (EDS), and a second stage in vivo in animals. For this they were supplied by the company Implacil - Dental Materials (Implants Debortoli) 24 cylindrical implants, which were divided into two groups: 1 - Implants blasted by TiO, 2 - and microtextured blasted implants byimmersion in hydrofluoric acid. The results showed that the first phase the implants evaluated in the SEM group 2 had a surface morphology much more uniform and regular than group 1.The analysis by EDS also in group 2 was better, but no identification of any contaminant in their samples was found, in contrast to group 1 which had the presence of aluminum. In the second phase six rabbits were used receiving 2 implants in each tibia. It was observed the rate of bone corticalization in contact with the surface, after eight weeks, had an average rate of 37.10% in group 1 and 58 73% in group 2. In conclusion we can see that you can control the physical and chemical microtexturization of the surface of implants and that it gives a more uniform forming surface, eliminates the possibility of contaminants, increasing the rate of osseointegration andformation of bone cortical tissue.

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OBJECTIVES: To investigate apicectomies performed using burs, a CO2 laser or an Er:YAG laser and to evaluate the following aspects: morphology of apicectomized surfaces, presence of failures at the dentin/obturation material interface (marginal fit) of the apical portions of the root canals, and the proportions of chemical elements in the apicectomized surfaces. STUDY DESIGN: Twenty-four teeth were divided into three groups of eight and each group underwent apicectomy by one of three different ablation techniques: bur, CO2 laser or Er:YAG laser. The morphology of the apicectomized surfaces was then analyzed using scanning electron microscopy and their chemical composition was analyzed by energy dispersive spectroscopy. RESULTS: Surfaces produced with ablation by bur exhibited less surface irregularities and better marginal fit, while ablation with the CO2 laser caused intense surface carbonization and failures in obturation material fit. CONCLUSIONS: Our results suggest that, taking into consideration their clinical application, ablation of tooth apices using burs proved to be the best option among those tested here.

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O objetivo desse estudo foi caracterizar in vitro e avaliar in vivo implantes jateados com partículas de TiO. A caracterização in vitro foi feita com a obtenção de imagens em MEV e verificação da superfície por EDS. Para as avaliações in vivo foram utilizados três coelhos New Zelands, adultos, com peso médio de 3,5 Kg, obtidos no Biotério Central da UFSM. Foram utilizados 12 implantes cilíndricos de hexágono interno, fabricados pela empresa Implacil Material Odontológico (Implantes Bortoli), os quais apresentam superfície jateada por TiO. Marcadores ósseos (alizarina, calceina, tetraciclina) foram injetados subcutaneamente em diferentes intervalos de tempo após a implantação para avaliar o tempo de formação do novo osso no período de oito semanas. As amostras foram cortadas em um micrótomo obtendo-se três cortes de cada implante, sendo um para cada técnica histológica: microscopia de luz, microscopia de fluorescência e microscopia de varredura, onde foram analisadas e comparadas as áreas de contato entre osso/implante. Os resultados demonstraram que a superfície proposta promove uma osseointegração muito efetiva e em uma sequência de tempo adequada e esperada. Os implantes apresentaram grandes áreas de osso corticalizado, chegando a média de 67,8% de contato entre osso cortical/implante e uma característica de osso lamelar presente em praticamente toda a superfície. Assim, concluiu-se que a superfície apresentada pelos implantes Bortoli, jateada por partículas de oxido de titânio, tem boa capacidade osseocondutora, promovendo adequado crescimento ósseo e corticalização em sua superfície após oito semanas.

The aim of this study was to make in vitro and in vivo characterizations of a dental implant blasted with TiO2 particles. The in vitro characterization was made with SEM and EDS techniques. For in vivo evaluation, three New Zealand adult rabbits were selected, with an average weight of 3.5kg, obtained from Central Animal UFSM. A total of 12 TiO2-blasted, cylindrical internal hexagon implants (Implacil Dental Material, Bortoli Implants), were used. Bone markers (alizarin, calcein, and tetracycline) were injected subcutaneously at different time intervals after implantation to assess the time of formation of new bone within 8 weeks. The samples were cut in a microtome obtaining three sections of each implant, one for each technique: light microscopy, fluorescence microscopy, and scanning electron microscopy, which analyzed and compared bone/implant contact areas. The results demonstrated that the proposed surface promotes osseointegration in a very effective and a proper time sequence as expected. The implants showed large areas of bone formation, reaching an average of 67.8% of cortical bone/implant contact, and characteristic lamellar bone present on virtually all surfaces. Thus, we concluded that the TiO2-blasted Bortoli implant has a good osteoconductive capacity by promoting adequate bone growth and cortical formation on its surface after 8 weeks.

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Nos últimos anos diferentes desenhos de implantes têm sido sugeridos e desenvolvidos para a utilização na substituição de perdas dentais. Dentre esses, os mais comuns são os implantes cilíndricos e cônicos, sendo esse último, atualmente mais procurado pela sua facilidade de inserção e melhor estabilidade primária. O objetivo deste estudo foi avaliar a interface osso/implante da superfície tratada por jateamento com micropartículas de óxido de titânio em dois tipos modelos de implantes dentais, analisando comparativamente a diferença e direcionamento do crescimento do tecido ósseo em contato de cada modelo através de fotomicrografias obtidas pela microscopia eletrônica de varredura (MEV). Foram utilizados três coelhos New Zelands, adultos, com peso médio de 3,5Kg, obtido no Biotério Central da Universidade Federal de Santa Maria (UFSM). Foram utilizados 6 implantes cilíndricos e 6 implantes cônicos de hexágono interno fabricados pela empresa Implacil Material Odontológico (Implantes Bortoli), os quais apresentam superfície jateada por óxido de titânio. Marcadores ósseos (Alizarina, calceina, tetraciclina) foram injetados subcutaneamente em diferentes intervalos de tempo após a implantação para avaliar o tempo de formação do novo osso no período de 8 semanas. Após as oito semanas os animais foram sacrificados e os implantes removidos com uma porção de tecido ósseo e fixadas em e fixadas solução a base de formol por três dias. Na sequência essas foram desidratadas em álcool e incluídas em resina especial para microscopia. Foram realizados cortes em um micrótomo para a obtenção das amostras, sendo obtidos 3 cortes de cada, as quais foram analisadas e comparadas verificando-se as áreas de contato das superfícies com o tecido ósseo por microscopia de luz, de fluorescência e de varredura. Os resultados demonstraram que a superfície proposta promove uma osseointegracão muito efetiva e em uma sequência de tempo adequada e esperada e, que o desenho do implante cônico parece ter direcionado o crescimento do osso cortical em uma maior área de superfície. Concluiu-se que o modelo de desenho do implante pode influenciar a qualidade e quantidade de osseointegracão dos implantes dentais e pode direcioná-la, porém novos estudos sobre essa área de contato osso/implante devem ser propostos.

In recent years various designs of implants have been suggested and developed for use in replacing tooth losses. Among these, the most common implants are cylindrical and conical, the latter being currently most sought by its ease of insertion and better primary stability. The aim of this study was to evaluate the bone-implant interface surface treated by sandblasting with microparticles of titanium oxide models into two types of dental implants, comparatively analyzing the difference and direction of growth of bone tissue in contact for each model by photomicrographs by scanning electron microscopy (SEM). We used three rabbits New Zelands adults, with an average weight of 3.5 kg, obtained from Central Animal of University Federal of Santa Maria (UFSM). Six implants cylindrical and six conical implants with internal hexagon were used, manufactured by the company Implacil Dental Materials (Implants Bortoli), which have blasted surface of titanium oxide. Bone markers (alizarin, calcein, tetracycline) were injected subcutaneously at different time intervals after implantation to assess the time of formation of new bone within 8 weeks. After eight weeks the animals were sacrificed and the implants removed with a portion of bone tissue and fixed and fixed based solution of formaldehyde for three days. Following these were dehydrated in alcohol and embedded in special resin for microscopy. Cuts were made in a microtome to obtain the samples, obtained from three sections of each, which were analyzed and compared by checking whether the contact areas of surfaces with the bone tissue by light microscopy, fluorescence and scanning. The results demonstrated that the proposed surface promotes osseointegration in a very effective and proper time sequence and expected, and the tapered design of the implant seems to have driven the growth of cortical bone in a larger surface area. It was concluded that the model of implant design can influence the quality and quantity of osseointegration of dental implants and can direct it, but further studies on this area of bone to implant contact should be proposed.

Assuntos

RESUMO

OBJETIVO: analisar, por meio de microscopia eletrônica de varredura, as alterações químicas e estruturais de braquetes metálicos submetidos a um processo de biodegradação in vitro. MÉTODOS: a amostra foi dividida em dois grupos, de acordo com a marca comercial dos acessórios - Grupo A = Dyna-Lock, 3M/Unitek (AISI 303) e Grupo B = LG Edgewise Standard, American Orthodontics (AISI 316L). Os corpos de prova, aparelhos ortodônticos simulados, permaneceram imersos em solução salina (0,05 por cento) por um período de 60 dias, a 37ºC, sob agitação. As alterações decorrentes da exposição dos acessórios à solução salina foram investigadas através da observação com microscópio eletrônico de varredura (MEV) e análise da composição química (EDX), realizadas antes e após o período de imersão (T0 e T5, respectivamente). RESULTADOS: em T5, houve formação de produtos de corrosão sobre a superfície dos braquetes, especialmente no Grupo A, além disso, houve alterações na composição da liga metálica dos braquetes de ambos os grupos, sendo que, no Grupo A, houve redução dos íons ferro e cromo e, no Grupo B, redução de íons cromo. CONCLUSÃO: os acessórios do Grupo A apresentaram-se menos resistentes à biodegradação in vitro, o que poderia estar associado ao tipo de aço utilizado em sua fabricação (AISI 303).

OBJECTIVES: The purpose of this study was to analyze, with the aid of scanning electron microscopy (SEM), the chemical and structural changes in metal brackets subjected to an in vitro biodegradation process. METHODS: The sample was divided into three groups according to brackets commercial brand names, i.e., Group A = Dyna-Lock, 3M/Unitek (AISI 303) and Group B = LG standard edgewise, American Orthodontics (AISI 316L). The specimens were simulated orthodontic appliances, which remained immersed in saline solution (0.05 percent) for a period of 60 days at 37°C under agitation. The changes resulting from exposure of the brackets to the saline solution were investigated by microscopic observation (SEM) and chemical composition analysis (EDX), performed before and after the immersion period (T0 and T5, respectively). RESULTS: The results showed, at T5, the formation of products of corrosion on the surface of the brackets, especially in Group A. In addition, there were changes in the composition of the bracket alloy in both groups, whereas in group A there was a reduction in iron and chromium ions, and in Group B a reduction in chromium ions. CONCLUSIONS: The brackets in Group A were less resistant to in vitro biodegradation, which might be associated with the type of steel used by the manufacturer (AISI 303).