345 resultados para Dental implant


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Superficial digital flexor tendonitis is an important cause of lameness in horses and its incidence ranges from 13% to 30%, depending on the horse's activity. This injury can occur in yearlings and compromise its carriers by reinjury or even impossibility to return to athletic life. In spite of the long period required for tendon repair, the scar tissue presents lack of elasticity and stiffness. As current treatment strategies produce only marginal results, there has been great interest in research of therapies that influence the quality or the speed of tendon repair. Stem cell therapy has shown promising results in degenerative diseases and cases of deficient healing processes. This study aims to evaluate the influence of autologous mesenchymal bone marrow stem cells in tendon healing, comparing treated and non-treated tendons. Superficial digital flexor tendonitis lesions were induced by collagenase infiltration in both forelimbs of 6 horses, followed by autologous implant in one of the forelimbs of each animal. The horses were evaluated using clinical, ultrasonographic, histopathologic, and immunohistochemical parameters. Tendon biopsies were performed at Day 48. Results found in the treatment group, such as high inflammatory cells infiltration, extracellular matrix synthesis, reduced amount of necrosis areas, small increase in cellular proliferation (KI-67/MIB-1), and low immunoreactivity to transforming growth factor P I, suggested the acceleration of tendon repair in this group. Further studies should be conducted in order to verify the influence of this treatment on later phases of tendon repair. Overall, after analysis of the results, we can conclude that cellular therapy with the mononuclear fraction of bone marrow has accelerated tendon repair at 48 days after treatment.

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The aims of this study were to develop a dental chart evaluate any oral cavity disease, develop gypsum models the dental arches, and to register the occlusions found in coatis (Nasua nasua) in captivity. Formulation of the dental chart was assisted by intraoral radiographs from the head of an adult coati cadaver of the same species with the following dental formula: I 3/3, C 1/1, P 4/3, M 2/2. Seven live coatis of the Nasua nasua species were evaluated. Five of the seven coatis presented with various dental abnormalities as follows: dental plaque (71.4 %), gingivitis (71.4 %), periodontitis (57.1 %), dental stain (42.9 %), dental abrasion (57.1 %), dental fracture (57.1 %), pulp exposure (42.9 %), malocclusion (5 7.1 %) and supernumerary teeth (14.2 %).

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The purpose of this study was to analyze the alpha-amylase (sAA) and cortisol levels in children with Global developmental delay (GDD) before and after dental treatment and its association with the children's behavior during treatment. The morning salivary cortisol levels and activity of sAA of 33 children with GDD were evaluated before and after dental treatment and were compared to 19 healthy children. The behavior of children with GDD during dental care was assessed by the Frankl scale. Children with GDD showed lower levels of sAA activity than healthy children, but this result was not significant. The salivary cortisol levels were similar between GOD and healthy children. GDD children showed increased levels of sAA (but not cortisol) prior to the dental treatment as compared to the post-treatment phase. GOD children who showed less favorable behavior during dental care had higher levels of sAA and salivary cortisol than GOD children with more favorable behavior, but only the sAA results were significant. In conclusion, GOD children show hyperactivity of the SNS-axis in anticipation of dental treatment which indicates the need for strategies to reduce their anxiety levels before and during dental care. (C) 2011 Elsevier Ltd. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Surface and biomechanical analysis of titanium implant surfaces modified by laser beam with and without hydroxyapatite. Titanium implants with 3 different surfaces were inserted into the tibias of 30 rabbits: group I (GI) machined surface (control group), group II irradiated with laser (GII), and group III irradiated with laser and hydroxyapatite coating applied-biomimetic method (GIII). Topographical analysis with scanning electron microscopy was made before surgery in the tibia. These rabbits were distributed into 2 periods of observation: 4 and 8 weeks postsurgery, after which biomechanical analysis (removal torque) was conducted. Statistical analysis used the Student-Newman-Keuls method. Surface showed roughness in GII and GIII. Biomechanical analysis demonstrated values with significant differences in GII and GIII. Titanium implants modified by laser irradiation can increase osseointegration during the initial phase.

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The aim of this study was to assess the behavior and stress distribution of 3 retention systems associated with implant for facial prosthesis by using the photoelasticity method. A photoelastic model was made from the replica of the orbital region on the left side of a dry skull with two 4-mm implants fixed in the superior orbital region. Three facial prosthetic retention systems were made for this study: O'ring, bar-clip, and magnets. The set (model/retention systems/prosthesis) was placed in a polariscope, and then traction began to be applied to the retention systems. The limit values for removal of the retention system were obtained by tests performed in an EMIC Universal test machine. The results were obtained by observation during the experiments and by photographic record of the stress behavior in the photoelastic model, resulting from the traction of the retention systems. In the magnet system, a lowest formation of fringes was verified both around and between the implants; in the O'ring system, the formation of photoelastic fringes was noted between the implants in the apical region; and in the bar-clip system, there was a greater concentration of colored fringes in the regions between the implants and cervical area. Based on the results obtained, it was concluded that the retention systems produced different stress distribution characteristics that, in general, were concentrated in the area around the implants, and the highest concentration of fringes, in increasing order, occurred ill the retention systems of the magnets, O'ring, and bar-clip.

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The teeth most commonly affected by trauma are the maxillary central incisors. The most frequent types of traumatic dental injuries to permanent teeth are enamel fractures, enamel and dentine fractures, and enamel and dentine fractures with pulp involvement. This article describes three clinical cases with different levels of traumatized maxillary incisors and several cosmetic approaches for recovery of the esthetics and the masticatory function, as well as the social/psychological aspects of treatment. All cases involved young adult men. The three clinical cases involve dentin and enamel fractures, dentin and enamel fractures with pulp exposure, and dentin and enamel fractures with pulp exposure associated with root fracture. The cosmetic treatments used to resolve fractures were direct composite resin by layering technique, indirect all-ceramic restorations (laminate veneer and ceramic crowns over the teeth), and immediate implant after extraction followed by immediate loading (ceramic abutments with ceramic crown over implant). In all three cases, excellent functional and esthetic results were achieved by use of these treatment modalities. The patients were very satisfied with the results.

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The aim of this study was to evaluate implants installed with compromised primary stability associated or not with polylactide and polyglycolide copolymer (PLA/PGA). Two 0.4-mm overdrilled defects (3 mm in diameter and 6 mm long) were produced in the right tibia of 25 rabbits. Half of the defects were left untreated, and the other half was filled with PLA/PGA. Implants of 2.6 mm in diameter and 6 mm long were placed into all defects. Animals were killed at 5, 15, 40, and 60 postoperative days, and biomechanical analysis (torque-reverse), histomorphometry, and immunohistochemistry (osteoprotegerin, receptor activator of NFJB ligand [RANKL], osteocalcin, and collagen-1 [ COL- I] staining) were performed. All the implants achieved osseointegration. There were no statistically significant differences in the torque-reverse and in linear contact extension between bone tissue and implant surface and no statistically significant difference in osteoprotegerin, RANKL, osteocalcin, and collagen-1 expression between the studied groups in all studied periods (P > 0.05). We can conclude that osseointegration can occur in compromised primary implant stability situations, and the addition of PLA/PGA did not improve the osseointegration process in this experimental model.

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Purpose: This study sought to evaluate the effect of repeated implant drilling on the immediate bone-cell viability, and to evaluate drill wear by scanning electron microscopy.Materials and Methods: The tibiae of 10 rabbits were used, divided into 5 groups (G): G1 corresponded to new drills, and G2, G3, G4, and G5 corresponded to drills used 10, 20, 30, and 40 times, respectively. The animals received 10 sequential osteotomies in each tibia. The animals were euthanized immediately after the osteotomies by perfusion with 4% formaldehyde. Samples then underwent immunohistochemistry processing for ordinal qualitative analysis of osteoprotegerin (OPG), the RANK ligant (RANKL; a tumor-related necrosis factor receptor family), and osteocalcin protein immunolabels, as detected by the immunoperoxidase method and revealed with 3,3-diaminobenzidine. Drill wear and plastic deformation were analyzed by scanning electron microscopy (SEM).Results: The proteins were expressed in osteocytes of the superior bone cortical during the 40 drillings. However, in G4 and G5, a discrete increase in the expression of RANKL was observed, when compared with OPG; this increase was statistically significant in G5 (P = .016). The SEM analysis revealed major plastic deformation and drill wear in G4 and G5.Conclusion: Based on the present methodology, it may be concluded that cell viability is preserved if a less traumatic surgical protocol is used. However, the repeated use of drills alters the protein balance as of the thirtieth perforation. (C) 2008 American Association of Oral and Maxillofacial Surgeons.

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Objective. The aim of this study was to evaluate the rat alveolar socket response to implanted polyethylene tubes filled with a light-cured MTA or Angelus MTA.Study design. Fifty-seven Wistar rats received an implant filled with one of the materials in the dental socket of the right central incisor. After 30, 60, and 90 days, animals were killed, and the right hemimaxillas were removed and processed to be analyzed on light microscopy. After embedding in paraffin, 6-mu m-thick sections were obtained and stained with hematoxylin and eosin. Qualitative and quantitative analyses of the reaction were performed.Results. It was observed that the light-cured MTA presented a similar response compared with Angelus MTA, characterized by the reduction of the chronic inflammatory response and organization of the alveolar bone close to the materials, especially at the 90th day of observation.Conclusions. It was concluded that both materials were well accepted by the alveolar tissue of rats, with the formation of mineralized tissue close to the materials. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:e93-e97)

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This article reports the 20-month clinical outcome of the use of 4 zygomatic implants with immediate occlusal loading and reverse planning for the retreatment of atrophic edentulous maxilla after failed rehabilitation with autogenous bone graft reconstruction and maxillary implants. The intraoral clinical examination revealed mispositioned and loosened implants underneath a maxillary complete denture. The panoramic radiograph showed 6 maxillary implants. One implant was displaced into the right maxillary sinus, and the implant anchored in the region of tooth 21 was fractured. The other implants presented peri-implant bone loss. The implants anchored in the regions of teeth 21 to 23 and 11 to 13 were first removed. After 2 months, the reverse planning started with placement of 4 zygomatic fixtures, removal of the implants migrated into the sinus cavity and anchored in the region of tooth 17, and installation of a fixed denture. After 20 months of follow-up, no painful symptoms, peri-implant inflammation or infection, implant instability, or bone resorption was observed. The outcomes of this case confirm that the zygoma can offer a predictable anchorage and support function for a fixed denture in severely resorbed maxillae.

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Dental trauma, particularly tooth avulsion, is a frequent cause of tooth loss in children, adolescents, and young adults. The avulsed tooth should be immediately reimplanted in its alveolus. This procedure can be performed by anyone at the accident site and not only by dental surgeons. Therefore, the purpose of this study is to evaluate the knowledge of sixth graders of the city of Aracatuba, SP, about dental avulsion and tooth reimplantation through a structured and standardized survey. Our sample consisted of 778 students. The data collected was processed using the program epiinfo 2000. Most students were around 12 years of age and 94.5% related to practice some kind of sports. Results demonstrated that the possibility of tooth reimplantation after dental avulsion is not acknowledged among these students and dental traumatism was associated to caries, toothache, and use of orthodontic appliances. Only 18.9% of the students associated dental traumatism to an impact trauma; 3.6% would store the tooth in milk, and 3.1% believed the tooth could be reimplanted by anyone present at the accident site. In summary, the results show an overall the lack of knowledge about dental traumatism and highlight the need of special programs designed to educate school-aged students about emergency procedures to handle cases of dental traumatisms.

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Computed tomographic scanning is a precise, noinvasive surveying technique that enables the professionals to improve the precision of implant placement by building a prototype that allows the confection of surgical guides. The authors present a clinical case of anterior tooth rehabilitation with frozen homogenous bone graft and immediately loaded titanium implant using computer-guided surgery. A multislice computed tomography was realized, and a prototype was built. All the procedures were previously realized in the prototype before started in the patient. This technique allows a better surgical planning, makes the procedures more accurate, and reduces surgery time.