RESUMO
The aim of this study was to evaluate the influence of implant macrodesign and surface hydrophilicity on osteoclast (OC) differentiation, activation, and survival in vitro. Titanium disks were produced with a sandblasted, dual acid-etched surface, with or without additional chemical modification for increasing hydrophilicity (SAE-HD and SAE, respectively) and different macrodesign comprising trapezoidal (HLX) or triangular threads (TMX). This study evaluated 7 groups in total, 4 of which were experimental: HLX/SAE-HD, HLX-SAE, TMX/SAE-HD, and TMX/SAE; and 3 control groups comprising OC differentiated on polystyrene plates (CCPC): a positive CCPC (+), a negative CCPC (-), and a lipopolysaccharide-stimulated assay positive control group, CCPC-LPS. Murine macrophage RAW264.7 cells were seeded on the disks, differentiated to OC (RAW-OC) by receptor activator of nuclear factor-κB ligand (RANKL) treatment and cultured for 5 days. Osteoclast differentiation and cell viability were respectively assessed by specific enzymatic Tartrate-Resistant Acid Phosphatase (TRAP) activity and MTT assays. Expression levels of various OC-related genes were measured at the mRNA level by quantitative polymerase chain reaction (qPCR). HLX/SAE-HD, TMX/SAE-HD, and HLX/SAE significantly suppressed OC differentiation when compared to CCPC (+). Cell viability was significantly increased in TMX/SAE and reduced in HLX/SAE-HD. In addition, the expression of Interleukin (IL)-6 and Tumour Necrosis Factor (TNF)-α was upregulated in TMX/SAE-HD compared to CCPC (+). Hydrophilic surfaces negatively modulate macrophage/osteoclast viability. Specifically, SAE-HD with double triangular threads increases the cellular pro-inflammatory status, while surface hydrophilicity and macrodesign do not seem to have a distinct impact on osteoclast differentiation, activation, or survival.
Assuntos
Diferenciação Celular , Sobrevivência Celular , Interações Hidrofóbicas e Hidrofílicas , Osteoclastos , Propriedades de Superfície , Titânio , Titânio/química , Osteoclastos/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Camundongos , Fatores de Tempo , Condicionamento Ácido do Dente , Osteogênese/efeitos dos fármacos , Osteogênese/fisiologia , Teste de Materiais , Reprodutibilidade dos Testes , Fosfatase Ácida Resistente a Tartarato/análise , Análise de Variância , Ligante RANK/análise , Reação em Cadeia da Polimerase em Tempo Real , Células RAW 264.7 , Valores de Referência , Macrófagos/efeitos dos fármacosRESUMO
BACKGROUND: Prosthetic total joint replacement has been incorporated as a treatment for complex temporomandibular disorder; however, the survival of those devices is unknown. OBJECTIVE: To assess the survival rate of the total temporomandibular joint (TMJ) prothesis and their main causes of failure. METHODS: An electronic search was conducted in eight databases until March 2023. Prospective studies reporting the survival rate of total TMJ prothesis with a minimum follow-up of 12 months were included. Studies with partial TMJ prostheses or those no longer available on the market were excluded. Two reviewers assessed the individual risk of bias using the JBI Systematic Reviews for Quasi-experimental studies tool. Meta-analysis of proportions was conducted to summarise the survival rate, using 95% confidence intervals (CI). The GRADE approach assessed the certainty of the body of evidence. RESULTS: Data from 320 patients were collected from six prospective studies. The number of prothesis losses varied from none to four. All studies presented sources of bias related to follow-up description of the patients. The follow-up time varied from 12 months to 21 years. In most of the studies, prosthesis failure occurred within the first 6 months after surgery due to infection. The overall survival of total TMJ protheses was 97% (95% CI: 95%; 99%), with low heterogeneity (I2 = 29%) and a very low certainty of evidence. CONCLUSION: TMJ total prosthesis apparently is a safe procedure with a high survival rate and the evidence is very uncertain and presents important sources of bias.
Assuntos
Artroplastia de Substituição , Transtornos da Articulação Temporomandibular , Humanos , Bases de Dados Factuais , Articulação Temporomandibular/cirurgia , Transtornos da Articulação Temporomandibular/cirurgiaRESUMO
Abstract The aim of this study was to evaluate the influence of implant macrodesign and surface hydrophilicity on osteoclast (OC) differentiation, activation, and survival in vitro. Titanium disks were produced with a sandblasted, dual acid-etched surface, with or without additional chemical modification for increasing hydrophilicity (SAE-HD and SAE, respectively) and different macrodesign comprising trapezoidal (HLX) or triangular threads (TMX). This study evaluated 7 groups in total, 4 of which were experimental: HLX/SAE-HD, HLX-SAE, TMX/SAE-HD, and TMX/SAE; and 3 control groups comprising OC differentiated on polystyrene plates (CCPC): a positive CCPC (+), a negative CCPC (-), and a lipopolysaccharide-stimulated assay positive control group, CCPC-LPS. Murine macrophage RAW264.7 cells were seeded on the disks, differentiated to OC (RAW-OC) by receptor activator of nuclear factor-κB ligand (RANKL) treatment and cultured for 5 days. Osteoclast differentiation and cell viability were respectively assessed by specific enzymatic Tartrate-Resistant Acid Phosphatase (TRAP) activity and MTT assays. Expression levels of various OC-related genes were measured at the mRNA level by quantitative polymerase chain reaction (qPCR). HLX/SAE-HD, TMX/SAE-HD, and HLX/SAE significantly suppressed OC differentiation when compared to CCPC (+). Cell viability was significantly increased in TMX/SAE and reduced in HLX/SAE-HD. In addition, the expression of Interleukin (IL)-6 and Tumour Necrosis Factor (TNF)-α was upregulated in TMX/SAE-HD compared to CCPC (+). Hydrophilic surfaces negatively modulate macrophage/osteoclast viability. Specifically, SAE-HD with double triangular threads increases the cellular pro-inflammatory status, while surface hydrophilicity and macrodesign do not seem to have a distinct impact on osteoclast differentiation, activation, or survival.
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The risk of fracture or strain in mini-screws is higher if diameter, length, type of alloy or insertion angle is selected inappropriately. The aims of this study were to test the structural resistance of two types of orthodontic mini-screws -one made of stainless steel and another of titanium- from an international brand and to evaluate the efficacy of two other titanium miniscrews of Brazilian origin, during an extra-alveolar anchorage procedure. The mini-screws analyzed were: Bomei stainless steel and Bomei titanium / Taiwan, Morelli titanium and Neodent titanium/ Brazil. Experiments were conducted on pig mandibles to simulate the process of extra-alveolar anchorage. Two insertion processes were used: Direct at 30º, and Indirect, starting at 60º and ending at 30º with gradual continuous movement. Strain was evaluated using Optical and Scanning Electron Microscopy. Data were evaluated using Kruskal-Wallis non-parametric statistical analysis and post hoc Tamhane test. Significant statistical differences in strain were observed among the mini-screws used in the extra-alveolar insertions, both for the direct and indirect procedures. In the indirect insertion tests, both stainless steel and titanium mini-screws suffered deformation, showing that angling can be an important factor in mini-screw failure rates. The change in angle during the insertion movement increased deformation rates independently of alloy type, increasing the risk of failure. These results could help orthodontists in choosing mini-screws for extra-alveolar anchorage, which can be performed with direct or indirect insertion. In vivo studies should be conducted to confirm the findings of this study.
O risco de fratura ou tensão nos mini-parafusos é maior se o diâmetro, comprimento, tipo de liga ou ângulo de inserção for selecionado de forma inadequada. Os objetivos deste estudo foram testar a resistência estrutural de dois tipos de miniaparafusos ortodônticos um feito de aço inoxidável e outro de titânio de uma marca internacional e avaliar a eficácia de dois outros mini-parafusos de titânio de origem brasileira, durante um procedimento de ancoragem extra-alveolar. Os miniaparafusos analisados foram: Bomei aço inoxidável e Bomei titânio / Taiwan, Morelli titânio e Neodent titânio / Brasil. Foram realizadas experiências em mandíbulas de porcos para simular o processo de ancoragem extra-alveolar. Foram utilizados dois processos de inserção (Direta a 30º, e Indireta, começando a 60º e terminando a 30º com movimento gradual contínuo). A deformação foi avaliada utilizando Microscopia Óptica e Microscopia Eletrônica de Varredura. Os dados foram avaliados utilizando análise estatística não paramétrica Kruskal-Wallis e teste post-hoc Tamhane. Diferenças estatísticas significativas na deformação foram observadas entre os miniparafusos utilizados nas inserções extra-alveolares, tanto para os procedimentos diretos como indiretos. Nos testes de inserção indireta, tanto os mini-parafusos de aço inoxidável como os de titânio sofreram deformação, mostrando que a angulação pode ser um fator importante nas taxas de falha dos mini-parafusos. A mudança no ângulo durante o movimento de inserção aumentou as taxas de deformação independentemente do tipo de liga, aumentando o risco de falha. Estes resultados podem ajudar os ortodontistas na escolha de mini-parafusos para ancoragem extra-alveolar, que pode ser realizada com inserção direta ou indireta. Estudos in vivo devem ser conduzidos para confirmar os resultados deste estudo.
Assuntos
Implantes Dentários , Procedimentos de Ancoragem Ortodôntica , Animais , Parafusos Ósseos , Brasil , Mandíbula , Desenho de Aparelho Ortodôntico , Suínos , TitânioRESUMO
ABSTRACT The risk of fracture or strain in mini-screws is higher if diameter, length, type of alloy or insertion angle is selected inappropriately. The aims of this study were to test the structural resistance of two types of orthodontic mini-screws -one made of stainless steel and another of titanium- from an international brand and to evaluate the efficacy of two other titanium miniscrews of Brazilian origin, during an extra-alveolar anchorage procedure. The mini-screws analyzed were: Bomei stainless steel and Bomei titanium/Taiwan, Morelli titanium and Neodent titanium/ Brazil. Experiments were conducted on pig mandibles to simulate the process of extra-alveolar anchorage. Two insertion processes were used: Direct at 30°, and Indirect, starting at 60° and ending at 30° with gradual continuous movement. Strain was evaluated using Optical and Scanning Electron Microscopy. Data were evaluated using Kruskal-Wallis non-parametric statistical analysis and post hoc Tamhane test. Significant statistical differences in strain were observed among the mini-screws used in the extra-alveolar insertions, both for the direct and indirect procedures. In the indirect insertion tests, both stainless steel and titanium mini-screws suffered deformation, showing that angling can be an important factor in mini-screw failure rates. The change in angle during the insertion movement increased deformation rates independently of alloy type, increasing the risk offailure. These results could help orthodontists in choosing mini-screws for extra-alveolar anchorage, which can be performed with direct or indirect insertion. In vivo studies should be conducted to confirm the findings of this study.
RESUMO O risco de fratura ou tensao nos mini-parafusos é maior se o diámetro, comprimento, tipo de liga ou ángulo de insergao for selecionado de forma inadequada. Os objetivos deste estudo foram testar a resistencia estrutural de dois tipos de mini-aparafusos ortodónticos -um feito de ago inoxidável e outro de titànio- de uma marca internacional e avaliar a eficácia de dois outros mini-parafusos de titànio de origem brasileira, durante um procedimento de ancoragem extra-alveolar. Os mini-aparafusos analisados foram: Bomei ago inoxidável e Bomei titànio / Taiwan, Morelli titànio e Neodent titànio / Brasil. Foram realizadas experiencias em mandíbulas de porcos para simular o processo de ancoragem extra-alveolar. Foram utilizados dois processos de insergao (Direta a 30°, e Indireta, comegando a 60° e terminando a 30° com movimento gradual continuo). A deformagao foi avaliada utilizando Microscopia Optica e Microscopia Eletrónica de Varredura. Os dados foram avaliados utilizando análise estatistica nao paramétrica Kruskal-Wallis e testepost-hoc Tamhane. Diferengas estatisticas significativas na deformagao foram observadas entre os mini-parafusos utilizados nas insergoes extra-alveolares, tanto para os procedimentos diretos como indiretos. Nos testes de insergao indireta, tanto os mini-parafusos de ago inoxidável como os de titánio sofreram deformagao, mostrando que a angulagao pode ser um fator importante nas taxas de falha dos mini-parafusos. A mudanga no ángulo durante o movimento de insergao aumentou as taxas de deformagao independentemente do tipo de liga, aumentando o risco de falha. Estes resultados podem ajudar os ortodontistas na escolha de mini-parafusos para ancoragem extra-alveolar, que pode ser realizada com insergao direta ou indireta. Estudos in vivo devem ser conduzidos para confirmar os resultados deste estudo.
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OBJECTIVE: The aim of this study was to compare the outcomes of 2 surgical treatment options: one for correction of class II malocclusion skeletal deformity and one for pre-existing temporomandibular joint (TMJ) disorders requiring orthognathic surgery (OS) for correction of dentofacial deformity. STUDY DESIGN: This retrospective study evaluated patients who underwent OS with maxillomandibular advancement (MMA) with or without concomitant TMJ surgery for articular disk repositioning (ADR). Patients were divided into 2 groups: group I (MMA) was treated with OS only (18 patients); and group II (MMA-ADR) was treated with OS and concomitant ADR (19 patients). The sample consisted of 74 TMJs (mean patient age 29.86 years). RESULTS: In group I, 38.5% of the disks that were originally in normal position became displaced after OS, and 33.3% of displaced disks with reduction became nonreducing after OS. In group II, 78.9% of disks exhibited normal position in the final evaluation, and 97.3% of patients showed improved disk position after surgery. There was significant symptom improvement in all patients in group II, but no significant improvement in group I. CONCLUSIONS: OS with ADR appears to produce stable and beneficial results in improving symptoms in patients with displaced disk and TMJ pain.
Assuntos
Luxações Articulares , Cirurgia Ortognática , Adulto , Humanos , Imageamento por Ressonância Magnética , Côndilo Mandibular , Estudos Retrospectivos , Disco da Articulação Temporomandibular/diagnóstico por imagem , Disco da Articulação Temporomandibular/cirurgiaRESUMO
OBJECTIVE: This study analyzed the effect of ionizing radiation on bone microarchitecture and biomechanical properties in the bone tissue surrounding a dental implant. METHODOLOGY: Twenty rabbits received three dental morse taper junction implants: one in the left tibia and two in the right tibia. The animals were randomized into two groups: the nonirradiated group (control group) and the irradiated group, which received 30 Gy in a single dose 2 weeks after the implant procedure. Four weeks after the implant procedure, the animals were sacrificed, and the implant/bone specimens were used for each experiment. The specimens (n=10) of the right tibia were examined by microcomputed tomography to measure the cortical volume (CtV, mm3), cortical thickness (CtTh, mm) and porosity (CtPo, %). The other specimens (n=10) were examined by dynamic indentation to measure the elastic modulus (E, GPa) and Vickers hardness (VHN, N/mm2) in the bone. The specimens of the left tibia (n=10) were subjected to pull-out tests to calculate the failure load (N), displacement (mm) up to the failure point and interface stiffness (N/mm). In the irradiated group, two measurements were performed: close, at 1 mm surrounding the implant surface, and distant, at 2.5 mm from the external limit of the first measurement. Data were analyzed using one-way ANOVA, Tukey's test and Student's t-test (α=0.05). RESULTS: The irradiated bone closer to the implant surface had lower elastic modulus (E), Vickers hardness (VHN), Ct.Th, and Ct.V values and a higher Ct.Po value than the bone distant to the implant (P<0.04). The irradiated bone that was distant from the implant surface had lower E, VHN, and Ct.Th values and a higher Ct.Po value than the nonirradiated bone (P<0.04). The nonirradiated bone had higher failure loads, displacements and stiffness values than the irradiated bone (P<0.02). CONCLUSION: Ionizing radiation in dental implants resulted in negative effects on the microarchitecture and biomechanical properties of bone tissue, mainly near the surface of the implant.
Assuntos
Osso e Ossos/efeitos da radiação , Implantes Dentários , Radiação Ionizante , Animais , Fenômenos Biomecânicos , Osseointegração , Coelhos , Microtomografia por Raio-XRESUMO
OBJECTIVES: This study aimed to evaluate the effects of radiotherapy on biomechanical, histomorphometric, and microstructural characteristics of bone, in diverse periods, compared with intact bone tissue. MATERIALS AND METHODS: Eighteen adult male New Zealand rabbits were treated with a single radiation dose of 30 Gy. The animals were randomly divided into six groups: NoIr, control group, no radiation, and five irradiated groups sacrificed after 24 h (Ir24h), 7 (Ir7d), 14 (Ir14d), 21 (Ir21d), and 28 (Ir28d) days. After these periods, the animals were sacrificed and their tibias (n = 6) evaluated using three-point bending test to calculate the ultimate force, work to failure, and bone stiffness. Dynamic indentation test was used to quantify Vickers hardness and elasticity modulus of bone tissue. Micro-CT was used to analyze the cortical volume (CtV), cortical thickness (CtTh), and porosity (Ct.Po). Histomorphometric assessment was based on the lacunarity of bone tissue. Data were analyzed using one-way ANOVA and Kruskal-Wallis tests followed by Tukey, Dunnet, and Dunn's post-tests (P < 0.05). RESULTS: The ultimate force, work to failure, stiffness, elastic modulus, and Vickers hardness values of irradiated bone were significantly lower that non-irradiated bone. Irradiated bone showed significantly lower CtTh and CtV values and higher CtPo than non-irradiated bone. No significant difference was found for lacunarity between non-irradiated bone and irradiated bone. CONCLUSIONS: Ionizing radiation decreases normal anisotropy on microarchitecture of cortical bone, and increases bone fragility compared with non-irradiated bone. Further, these changes were seen after longer periods (e.g., 14 and 21 days), and not immediately after radiation therapy. CLINICAL RELEVANCE: The radiotherapy reduces bone mechanical properties and the normal structure of organic and inorganic bone matrix. For studying the protocols to protect the radiotherapy effect using rabbit model, the use of the sacrificing period between 14 and 21 days is recommended.
Assuntos
Osso e Ossos/efeitos da radiação , Radiação Ionizante , Radioterapia/efeitos adversos , Animais , Fenômenos Biomecânicos , Osso e Ossos/patologia , Módulo de Elasticidade , Masculino , Coelhos , Distribuição Aleatória , Tíbia , Microtomografia por Raio-XRESUMO
Oral surgery to remove pyogenic granuloma in a high-risk patient is reported. A 47-year-old man with gastroesophageal reflux disease, diabetes mellitus II, dyslipidemia, and chronic coronary insufficiency (myocardial infarction within 2 years) with episodes of unstable angina was submitted to an excisional biopsy of hemorrhagic lesion in the lingual right mandibular gingiva. During dental treatment, the arterial blood pressure, oxygen saturation, heart rate, and electrocardiogram were monitored. Local anesthesia was performed with 0.45 ml of 3% prilocaine with 0.03 IU/ml felypressin. The anticoagulant therapy was not interrupted. No local or systemic complications were noticed during or after the surgery.
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PURPOSE: The purpose of this study was to evaluate the effect of surface functionalization with bioactive glass BSF18 on the osseointegration of sandblasted and dual acid-etched surface (AE) implants. METHODS AND MATERIALS: Forty Morse taper implants with an AE surface as controls (C) or with an AE surface functionalized with BSF18 (BF) were placed in the mandibles of 10 beagles. Implants were analyzed after 2 and 4 weeks of healing. Implant stability quotient (ISQ) values were registered immediately after installation and prior to sacrifice. Samples were analyzed for bone-to-implant contact (BIC) and bone density (BD). The characterization of BF implants included surface roughness analysis with atomic force microscopy and contact angle (CA) analysis to evaluate wettability. Data were analyzed using two-way ANOVA followed by Tukey's test (p < 0.05). RESULTS: Surface roughness was not affected by BF treatment. CA was lower in the BF group compared to the C group. No significant difference was observed in ISQ values between surfaces (p = 0,231), irrespective of time. Significantly higher ISQ values were observed for both implants after 4 weeks when compared with baseline (p = 0.04). Significantly higher BIC (p = 0.011) and BD (p = 0.025) values were observed for the BF compared to the C group at 2 weeks. Significantly higher BIC (p = 0.030) and BD (p = 0.015) values for the C group were observed at 4 weeks compared to 2 weeks. No significant difference was observed in the BF group between 2 and 4 weeks. CONCLUSIONS: Implant functionalization with BSF18 improved the wettability of the implant surface; enhancing BIC and BD at 2 weeks.
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PURPOSE: The aim of this study was to evaluate the effect of different storage media on angiogenesis and maintaining autogenous bone graft volume in rabbits. MATERIAL AND METHODS: Two grafts were removed bilaterally from the calvaria of 18 rabbits. One graft was removed and immediately fixed in the right mandibular angle (control group). The other graft was stored for 30 minutes in 1 of the following storage media (n = 6): saline solution (saline group), air exposure (dry group), or platelet-poor plasma (PPP group) and then retained by a screw in the right mandibular angle in the same animal. Four weeks later the animals were euthanized, and the grafted areas were harvested, fixed in 10% phosphate buffered formaldehyde solution, and embedded in paraffin. The 5-µm semi-serial sections were stained in hematoxylin and eosin and Mallory trichrome. RESULTS: Histologic analysis of all groups showed the bone graft was vascularized and well incorporated into the recipient site. The number of blood vessels decreased in the saline and dry groups compared with the control group (P < .03); in contrast, the number of blood vessels increased in the PPP group (P < .05). There were fewer osteoclasts in the saline group compared with the control group (P < .05). Furthermore, the saline group showed larger numbers of blood vessels than the dry group (P < .01). The PPP group showed larger bone graft volumes compared with the dry and saline groups (P < .01). In addition, the saline group showed larger bone graft volumes than the dry group (P < .01). CONCLUSIONS: PPP improved angiogenesis, maintained the volume of the autogenous bone graft, and was a better storage medium during the trans-surgical period than the dry and saline media.
Assuntos
Transplante Ósseo/métodos , Mandíbula/irrigação sanguínea , Mandíbula/cirurgia , Soluções para Preservação de Órgãos , Crânio/transplante , Animais , Autoenxertos , Plaquetas , Regeneração Óssea/fisiologia , Feminino , Mandíbula/fisiologia , Neovascularização Fisiológica , Plasma , CoelhosRESUMO
Temporomandibular joint (TMJ) recurrent dislocation is usually associated with jaw hypermobility or articular eminence anatomy. Patients who have stroke experience (CVA) can present joint and muscle tone changes, as laxity ligamentous and appearance of spastic muscle patterns in different parts of the body such as shoulder, elbow, wrist, hip, knee and face. This study reported two cases of patients with stroke sequelae who developed chronic dislocation of the jaw. It was concluded that these two clinical conditions appear to have some correlation, further studies with more patients needed to confirm this correlation.
A luxação recorrente da articulação temporo-mandibular ocorre quando o côndilo mandibular move-se para fora da cavidade glenóide e permanece travado anteriormente à eminência articular de forma repetitiva. Pacientes com histórico de acidente vascular cerebral podem apresentar alterações articulares e de tonicidade muscular. O presente estudo relatou dois casos clínicos de pacientes com seqüela de AVC, que desenvolveram luxação crônica da mandíbula. Concluiu-se que essas duas condições clinicas parecem apresentar alguma correlação clínica, sendo ainda necessário estudos com mais pacientes para confirmar tal correlação.
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Este caso clínico relata o uso de uma prótese obturadora tipo overdenture para compensar a deficiência estética em um paciente previamente irradiado. Um indivíduo do sexo masculino, 73 anos de idade, que possuía uma prótese sobre três implantes dentários foi acometido de câncer no seio maxilar e assoalho da órbita. Seis doses de cisplatina e 35 sessões de radioterapia (dose diária 1,8 Gy) foram executadas. Após a maxilectomia, apenas um implante restou na região anterior. O tratamento consistiu de uma prótese obturadora tipo overdenture com encaixe tipo Equator. O paciente retornou um ano depois, sem alterações estéticas e com nível de satisfação melhorado. Entretanto, o anel borrachoide do encaixe foi trocado. Reabilitações implantossuportadas e mucorretidas que recebem carregamento tardio pode melhorar o prognóstico de implantes dentais em pacientes irradiados. Este cuidado mostra que este cenário ainda requer maior atenção da comunidade científica, na busca por meios de prevenir e minimizar os danos causados pela radioterapia, por inovações tecnológicas e protocolos regenerativos que potencializem a osseointegração. Com isso, a Odontologia poderá contribuir ainda mais com a melhora da qualidade de vida de pacientes, devolvendo satisfação pessoal e autoestima.
This case describes the use of an obturator-type overdenture prosthesis to compensate for the aesthetic defi ciency in a previously irradiated patient. A 73 years-old male, who had a prosthesis on three dental implants was diagnosed with cancer in the maxillary sinus and orbital floor. Six doses of cisplatin and 35 radiotherapy sessions (daily doses of 1.8 Gy) were performed. After maxillectomy, only one implant survived in the anterior region. The treatment consisted of an obturator overdenture with the Equator attachment. The patient returned one year later without cosmetic changes and demonstrated an enhanced satisfaction level. However, the o-ring rubber was replaced. Implant-supported, mucosa-retained restorations receiving delayed loading can improve the prognosis of dental implants in irradiated patients. Also, this scenario still requires more attention from the scientific community seeking for new ways to prevent and minimize damages caused by radiation, technological innovations, and regenerative protocols that enhance osseointegration. Thus, dentistry can further contribute to improving the quality of life of patients, returning their personal satisfaction and self-esteem.
Assuntos
Humanos , Masculino , Idoso , Implantes Dentários para Um Único Dente , Revestimento de Dentadura , Neoplasias Bucais , Reabilitação Bucal , Radioterapia/efeitos adversos , Radioterapia/métodosRESUMO
The deleterious effects of ionizing radiation on the growth plate continue to be cause for concern. This study evaluated the ionizing radiation effects on bone development and growth plate in the tibia of rats. All animals were submitted to ionizing radiation on the left leg. The animals were divided into two groups and euthanized 30 and 60 days after radiation. The tibiae were removed and separated into groups: control 30 days, irradiated 30 days, control 60 days and irradiated 60 days. Animals in each group (n = 7) were used for macroscopic and histological analysis. The irradiated tibiae showed arrested growth, angular deformity and limb length discrepancy when compared with nonirradiated tibiae. There was statistical difference between control and radiation groups in all the parameters analyzed, except in the lateral-medial thickness of the distal epiphysis. Histological analysis showed evident changes in the growth plate, which was thicker in the Groups irradiated for 30 days, and irradiated for 60 days, compared with their respective controls. The growth plate showed wide areas with disorganized zones of chondrocytes and severely reduced calcification zone. It was concluded that ionizing radiation damaged the growth plate, compromised the endochondral ossification process, and resulted in complete arrest of bone development.
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Condrócitos/efeitos da radiação , Lâmina de Crescimento/efeitos da radiação , Radiação Ionizante , Tíbia/patologia , Tíbia/efeitos da radiação , Animais , Condrócitos/citologia , Histocitoquímica , Masculino , Ratos , Ratos Wistar , Tíbia/química , Tíbia/citologiaRESUMO
The aim of this study was to evaluate the stability and osseointegration of implant with different wettability using resonance frequency analysis (RFA) and histomorphometric analysis (bone implant contact, BIC; and bone area fraction occupied, BAFO) after 2 and 4 weeks in rabbit tibiae. Thirty-two Morse taper implants (length 7 mm, diameter 3.5 mm) were divided according to surface characteristics (n=8): Neo, sandblasted and dual acid-etched; and Aq, sandblasted followed by dual acid-etched and maintained in an isotonic solution of 0.9% sodium chloride. Sixteen New Zealand rabbits were used. Two implants of each group were installed in the right and left tibiae according to the experimental periods. The RFA (Ostell(r)) was obtained immediately and after the sacrifice (2 and 4 weeks). The bone/implant blocks were processed for histomorphometric analysis. Data were analyzed using two-way ANOVA followed by Tukey's test and Pearson's correlation for ISQ, BIC and BAFO parameters (p=0.05). No significant effect of implant, period of evaluation or interaction between implant and period of evaluation was found for BIC and BAFO values (p>0.05). Only period of evaluation had significant effect for RFA values at 4 weeks (p=0.001), and at 2 weeks (p<0.001). RFA values were significantly higher at the final period of evaluation compared with those obtained at early periods. There was a significant correlation between BIC values and BAFO values (p=0.009). Both implant surfaces, Aq and Neo, were able to produce similar implant bone integration when normal cortical bone instrumentation was performed.
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Implantes Dentários , Osseointegração , Animais , Coelhos , Propriedades de SuperfícieRESUMO
Abstract: The aim of this study was to evaluate the stability and osseointegration of implant with different wettability using resonance frequency analysis (RFA) and histomorphometric analysis (bone implant contact, BIC; and bone area fraction occupied, BAFO) after 2 and 4 weeks in rabbit tibiae. Thirty-two Morse taper implants (length 7 mm, diameter 3.5 mm) were divided according to surface characteristics (n=8): Neo, sandblasted and dual acid-etched; and Aq, sandblasted followed by dual acid-etched and maintained in an isotonic solution of 0.9% sodium chloride. Sixteen New Zealand rabbits were used. Two implants of each group were installed in the right and left tibiae according to the experimental periods. The RFA (Ostell(r)) was obtained immediately and after the sacrifice (2 and 4 weeks). The bone/implant blocks were processed for histomorphometric analysis. Data were analyzed using two-way ANOVA followed by Tukey's test and Pearson's correlation for ISQ, BIC and BAFO parameters (p=0.05). No significant effect of implant, period of evaluation or interaction between implant and period of evaluation was found for BIC and BAFO values (p>0.05). Only period of evaluation had significant effect for RFA values at 4 weeks (p=0.001), and at 2 weeks (p<0.001). RFA values were significantly higher at the final period of evaluation compared with those obtained at early periods. There was a significant correlation between BIC values and BAFO values (p=0.009). Both implant surfaces, Aq and Neo, were able to produce similar implant bone integration when normal cortical bone instrumentation was performed.
Resumo: O objetivo deste estudo foi avaliar a estabilidade e osseointegração de implantes com superfícies com diferentes molhabilidades empregando análise de frequência de ressonância (RFA) e histomorfometria (contato implante ósseo, BIC, e fração de área óssea ocupada, BAFO), nos períodos de 2 e 4 semanas em tíbias de coelhos. Trinta e dois implantes cone Morse (comprimento 7mm, diâmetro 3,5 mm), foram divididos de acordo com tratamento de superfície (n = 8): Neo, superfície jateada e condicionada com ácido; e Aq, superfície jateada e condicionada com ácido e mantida em solução isotônica de cloreto de sódio a 0,9%. Dezesseis coelhos tipo Nova Zelândia foram utilizados neste estudo. Dois implantes de cada grupo foram instalados nas tíbias direita e esquerda de acordo com os períodos experimentais. Os valores de RFA (Ostell(r)) foram obtidos imediatamente e após o sacrifício (2 e 4 semanas). Os blocos ósseos/implante foram processados para análise histomorfométrica. Os dados foram analisados usando ANOVA fatorial seguido pelo teste de Tukey e também por meio de correlação de Pearson para os fatores RFA, BIC e BAFO (P=0,05). Nenhum efeito significativo dos fatores tipo de implante, período de avaliação e da interação entre o tipo de implante e período de avaliação foram observados para os valores de BIC e BAFO. Apenas o período de avaliação resultou em efeito significativo para valores RFA após 2 semanas (p=0,001), e 4 semanas (p<0,001). Os valores de RFA valores foram significativamente mais elevados no final do período de avaliação em comparação com os obtidos em inicialmente. Houve correlação significativa entre os valores BIC e BAFO (p=0,009). Ambas as superfícies de implantes, Aq e Neo, são capazes de produzir adequada integração osso/implante em condição normal de instrumentação do osso cortical.
Assuntos
Animais , Coelhos , Implantes Dentários , Osseointegração , Propriedades de SuperfícieRESUMO
OBJECTIVE: The aim of this study was to assess changes in the superior airway space (SAS) in Class II patients undergoing orthognathic surgery with counterclockwise rotation of the maxillomandibular complex (MMC). STUDY DESIGN: A total of 23 patients (15 females and 8 males; mean age, 33 years) with symptoms of respiratory disease (mouth breathing) were studied. The patients were subjected to computed tomography analyses at two time intervals: T1 (preoperatively) and T2 (postoperative minimum of 6 months). The computed tomography images were exported to Dolphin Imaging 11.5 software to measure the surface area, minimum axial area, and volume of the SAS. RESULTS: The surgery (including a median mandibular advancement of 14 mm with an average rotation of 8 degrees) significantly increased the static SAS, with mean postoperative increases of 178 mm(2) in SA, 76.67 mm(2) in minimum axial area, and 10118.5 mm(3) in volume. A significant increase was also observed in the three-dimensional airspace following orthognathic surgery, which provided a greater permeability of the SAS in Class II patients. CONCLUSIONS: This confirmed the efficacy of this technique in the treatment of respiratory disorders.
Assuntos
Má Oclusão Classe II de Angle/cirurgia , Avanço Mandibular/métodos , Respiração Bucal/cirurgia , Procedimentos Cirúrgicos Ortognáticos/métodos , Adulto , Brasil , Feminino , Humanos , Masculino , Má Oclusão Classe II de Angle/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
The clinical performance of dental implants is strongly defined by biomechanical principles. The aim of this study was to quantify the Vicker's hardness (VHN) and elastic modulus (E) surround bone to dental implant in different regions, and to discuss the parameters of dynamic microindantion test. Ten cylindrical implants with morse taper interface (Titamax CM, Neodent; 3.5 mm diameter and 7 mm a height) were inserted in rabbit tibia. The mechanical properties were analyzed using microhardness dynamic indenter with 200 mN load and 15 s penetration time. Seven continuous indentations were made distancing 0.08 mm between each other perpendicularly to the implant-bone interface towards the external surface, at the limit of low (Lp) and high implant profile (Hp). Data were analyzed by Student's t-test (ï a=0.05) to compare the E and VHN values obtained on both regions. Mean and standard deviation of E (GPa) were: Lp. 16.6 ± 1.7, Hp. 17.0 ± 2.5 and VHN (N/mm2): Lp. 12.6 ± 40.8, Hp. 120.1 ± 43.7. No statistical difference was found between bone mechanical properties of high and low profile of the surround bone to implant, demonstrating that the bone characterization homogeneously is pertinent. Dynamic microindantion method proved to be highly useful in the characterization of the individual peri-implant bone tissue.