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1.
J Oral Implantol ; 47(4): 325-332, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32835368

RESUMO

Dental surgeons need in-depth knowledge of the bone tissue status and gingival morphology of atrophic maxillae. The aim of this study is to describe preoperative virtual planning of placement of 5 implants and to compare the plan with the actual surgical results. Three-dimensional (3D) planning of rehabilitation using software programs enables surgical guides to be specially designed for the implant site and manufactured using 3D printing. A patient with 5 teeth missing was selected for this study. The patient's maxillary region was scanned with cone-beam computed tomography (CBCT), and a cast model was produced. After virtual planning using ImplantViewer, 5 implants were placed using a printed surgical guide. Two weeks after the surgical procedure, the patient underwent another CBCT scan of the maxilla. Statistically significant differences were detected between the virtually planned positions and the actual positions of the implants, with a mean deviation of 0.36 mm in the cervical region and 0.7 mm in the apical region. The surgical technique used enables more accurate procedures compared with the conventional technique. Implants can be better positioned, with a high level of predictability, reducing both operating time and patient discomfort.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endóssea , Humanos , Imageamento Tridimensional , Impressão Tridimensional
2.
Arch Oral Biol ; 119: 104889, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32911119

RESUMO

OBJECTIVE: The objective of this study was to evaluate the effects of ozone therapy on wound healing formed experimentally in the oral cavity of rats. DESIGN: Two surgical wounds were generated on the cheeks of 24 Wistar rats, bilaterally. Half of the animals were submitted to ozone therapy on both wounds (experimental group) and the other half received no treatment (control group). In the experimental group, wounds were exposed to ozone gas 1, 2 or 3 (60 µg/mL) times. Evaluation of wound healing of the buccal mucosa was followed for 1, 3 and 7 days. The distribution of neutrophils, fibroplasia and angiogenesis were analyzed. Samples were classified in a healing numerical scale according to the inflammatory intensity. Data were submitted to Mann-Whitney and Kruskal-Wallis tests (α = 0.05). RESULTS: On day 1, wounds were similar in both groups, lesions were open and bloody with slightly minor bleeding in the ozone therapy group. On day 3, the group with ozone therapy was almost all refurbished and with higher angiogenesis, while the control group still had more bloody points and lower blood vessels. On day 7, both wounds were remodeled, with higher fibroplasia in the group that received ozone therapy. CONCLUSION: It can be concluded that ozone therapy was effective in improving angiogenesis and fibroblasts count in the buccal mucosa of rats.


Assuntos
Mucosa Bucal/lesões , Ozônio/uso terapêutico , Cicatrização , Animais , Fibroblastos , Neovascularização Fisiológica , Ratos , Ratos Wistar
3.
Materials (Basel) ; 11(12)2018 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-30545159

RESUMO

Aim and objectives: It is well known that the transcription factor NF-κB regulates multiple aspects of innate and adaptive immune functions and functions as a pivotal mediator of inflammatory responses. In the present study, we evaluated the trauma generated (inflammatory reaction) after osteotomy bone surgical procedures and placement of implants in the femoral cortical bone of Wistar rats. Surgical stress was evaluated measuring the release and activation of the NF-κB factor. Materials and Methods: Rats were divided into four groups (n = 10) and submitted to different surgical treatments: Control Group (G1 group), only bone perforation was performed without irrigation; Implant Group (G2 group), a titanium implant was inserted after bone perforation without irrigation; Irrigated Group (G3 group) perforations were performed with intense irrigation; and Vitaminic Compound Group (G4 group) surgical perforation was performed without irrigation and a vitaminic compound containing the principal ions present in the natural bone structure was used to fill the bone defect. All animals were euthanized six hours after the surgical procedure and NF-κB levels were determined through immunohistochemical stain followed by direct counting of labeled and unlabeled osteocytes. Results: Among different treated groups, the overall mean of the NF-κB positive cell count in all positions were higher for G1 group (33.4 ± 2.45 cells). NF-κB values were lower in the G2 group (28.9 ± 2.70 cells), whereas in the G3 group (24.3 ± 2.72 cells) as well as in G4 group still lesser NF-κB positive cells were counted (26.5 ± 2.60 cells). Conclusions: The results here presented suggest that maneuvers performed during osteotomy procedures can significantly affect inflammation levels. The NF-κB activation during the surgical procedures can be minimized and/or controlled thought the adequate irrigation or application of adequate substances.

4.
Surg Radiol Anat ; 40(10): 1119-1131, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29785677

RESUMO

PURPOSE: The purpose of this study was to analyze the frequency of visualization of anatomical bone features and their possible variations in the mandibular interforaminal region through cone-beam computed tomography (CBCT). METHODS: This is a cross-sectional study that evaluated CBCT scans of the mandible of 141 women and 61 men, obtained by imaging archives from two private clinics of dental radiology. The study analyzed the frequency of visualization of: lingual symphyseal foramen (LSF), additional mental foramen (AdMF), absence of mental foramen (AbMF), mandibular incisive canal (MIC), and anterior loop (AL). Length measurements for MIC and AL were determined at first and following that the respective distances towards vestibular and lingual cortical walls were also individually verified. Statistical analyses included: Student's t test, Chi-square test, and ANOVA for the evaluation of the anatomical features observed through panoramic and parasagittal images' reconstructions. RESULTS: LSF presence was found in 97%, MIC in 75.9%, AL in 24%, AdMF in 4.7%, and AbMF in 2.5%. Chi-square tests demonstrated value results of p < 0.05 only for the presence of left AL in women when compared to men. Mean values for length measures of MIC and AL were of 10.1 and 2.12 mm, respectively. Mean distance from AL towards vestibular and lingual cortical walls was of 2.53 and 4.05 mm, respectively. CONCLUSION: Anatomical variability concerning the mandibular interforaminal region emphasizes the importance of performing CBCT in pre-operative assessment of the mandible for surgical procedures with oral implants.


Assuntos
Variação Anatômica , Mandíbula/anatomia & histologia , Procedimentos Cirúrgicos Bucais/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Tomografia Computadorizada de Feixe Cônico , Estudos Transversais , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Bucais/métodos , Cuidados Pré-Operatórios/métodos , Adulto Jovem
5.
Microsc Res Tech ; 81(6): 579-589, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29532542

RESUMO

Synthetic biomaterials submitted to new structural technologies have become ideal for the recovery of traumatized bone tissues and some bone substitutes such as bioactive glass, ß-Tricalcium phosphate (ß-TCP) and amorphous calcium phosphate (ACP) are being used in areas of tissue defects. For this study, ACP was produced in the form of fibers and then submitted to cytotoxicity testing. A sample of ACP was inserted into the mandibular region of a patient with a lost implant so after removal and curettage, the remaining bone site was filled with the ACP biomaterial. Preliminary cytotoxicity test was negative. After 15 weeks of healing, a titanium implant was inserted at the site. Clinical and radiographic follow-up was conducted for 12 months and sequential radiographic analyses revealed tissue formation resembling spongy bone. Images under immunohistochemistry demonstrated efficient deposition and osteoconduction of the newly deposited tissue. Residual portion of the CaO:P2 O5 outer layers served as a substrate for osteoid matrix deposition, aiding growth, and the results of fiber absorption favored maturation of the new bone tissue.


Assuntos
Materiais Biocompatíveis/farmacologia , Substitutos Ósseos/farmacologia , Fosfatos de Cálcio/farmacologia , Osteogênese/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Apatitas/metabolismo , Implantação Dentária/métodos , Humanos , Osseointegração/fisiologia
6.
Int J Oral Maxillofac Implants ; 31(3): 571-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27183066

RESUMO

PURPOSE: To evaluate supracortical bone neoformation with the use of hydroxyapatite (HA) hollow domes specially manufactured for osteogenesis promotion. MATERIALS AND METHODS: Nine New Zealand rabbits were selected and 18 domes were placed, divided into three groups according to the filler: control (blood clot), vitamin complex, and particulate ß-tricalcium phosphate (ß-TCP). The healing period was 8 weeks, hence fluorescent markers were applied. After healing, the samples were embedded in resin to prepare slides for light and fluorescence microscopic evaluation of the amount of neoformed bone tissue. Energy dispersive spectroscopy was also used for chemical analysis of the material inside the domes. RESULTS: The quality of neoformed bone tissue with active bone remodeling areas was observed. As a filler, ß-TCP showed higher bone formation (14.1%), better quality of neoformed bone tissue with organized structures, and an area of mineralized tissue in the dome. Bone neoformation inside the dome filled with blood clot confirmed the osteoconductive property of HA, as indicated by the migration of osteogenic cells from the blood clot, without the action of another biomaterial (mean area of bone formation for blood clot filler = 7.5%). Bone neoformation was not favored in samples filled with vitamin complex because of the difficulty of blood penetration through the material. CONCLUSION: HA domes performed well as a scaffold for bone neoformation over the cortical bone of rabbits, and this is based on maintenance of good stability and good integration with bone tissue. ß-TCP presented higher values of neoformed bone area compared with the blood clot. HA domes have osteoconductive properties, especially when filled with blood clot, because of the migration of osteogenic cells without action of any other biomaterial. In domes filled with vitamin complex, no bone formation was noted because of the absence of resorption.


Assuntos
Regeneração Óssea/fisiologia , Substitutos Ósseos/química , Durapatita/química , Osteogênese/fisiologia , Tíbia/fisiologia , Alicerces Teciduais/química , Animais , Materiais Biocompatíveis , Fosfatos de Cálcio/administração & dosagem , Modelos Animais de Doenças , Coelhos , Tíbia/cirurgia , Vitaminas/administração & dosagem , Cicatrização/fisiologia
7.
PLoS One ; 10(10): e0140630, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26465330

RESUMO

The present study investigated the moment of peak NF-kB activation and its dissipation in the cortical bone in the femur of Wistar rat stimulated by surgical trauma. Sixty-five Wistar rats were divided into 13 groups (n = 5 per group): eight experimental groups (expG 1-8) divided based on the euthanasia time point (zero, 1 h, 2 h, 4 h, 6 h, 8 h, 12 h and 24 h) and five sham control groups (conG 1-5) killed at zero, 1 h, 2 h, 4 h and 6 h, respectively. A 1.8-mm-diameter defect was generated 0.5 mm from the femur proximal joint using a round bur to induce the surgical trauma. Overall, the activation peak of NF-κB in the cortical bone was 6 h (expG5 group) independent of the evaluated position; this peak was significantly different compared to those in the other groups (p < 0.05). The surgical trauma resulted in a spread of immune markings throughout the cortical bone with an accentuation in the knee region. The present study provides the first evidence that the NF-κB activation peak was established after 6 hours in the cortical bone of Wistar rats. The signs from a surgical trauma can span the entire cortical bone and are not limited to the damaged region.


Assuntos
Osso e Ossos/metabolismo , Traumatismos do Joelho/genética , NF-kappa B/biossíntese , Ferimentos e Lesões/genética , Animais , Osso e Ossos/lesões , Osso e Ossos/patologia , Fêmur/lesões , Fêmur/metabolismo , Fêmur/patologia , Regulação da Expressão Gênica , Humanos , Inflamação/genética , Inflamação/patologia , Traumatismos do Joelho/patologia , NF-kappa B/genética , Ratos , Ratos Wistar , Ferimentos e Lesões/patologia
8.
J Mater Sci Mater Med ; 26(1): 5340, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25578694

RESUMO

The fascicular composition and organisation of the inferior alveolar nerve (IAN) were determined to confirm the microarchitecture of the IAN bundles into each of the mandibular teeth, including the composition of the mental nerve. The aim of this study was to evaluate peripheral nerve repair after the application of an antioxidant compound to the damaged nerve tissue to elevate the concentration and bioavailability of elements capable of favouring tissue repair. Twenty-five Wistar rats were divided into groups: The Control 1 (Ctl 1) (n = 5) animals had the ischiatic nerve exposed with no suture injury and were sacrificed at 30 days post-operatively. The Control 2 (Ctl 2) (n = 10) animals had the ischiatic nerve exposed, and the nerve was injured using suture in three distinct regions. In the experimental (Exp) animals (n = 10), an antioxidant organic compound was applied to the nerve injury site. The animals with nerve injury (Ctl2 and Exp group) were sacrificed at 15 and 30 days post-operatively. The histological analysis showed less degeneration in the Exp group at 15 and 30 days post-operatively. Nerve neoformation forming a connection between the distal and proximal suture sites was observed in the experimental group. This study presented an alternative to nerve repair using an antioxidant compound.


Assuntos
Antioxidantes/uso terapêutico , Doenças do Sistema Nervoso/tratamento farmacológico , Animais , Masculino , Ratos , Ratos Wistar
9.
Materials in medicine ; 26: 2-8, 2015.
Artigo em Português | LILACS, Sec. Est. Saúde SP, SESSP-IALPROD, Sec. Est. Saúde SP, SESSP-IALACERVO | ID: biblio-1017056

RESUMO

The fascicular composition and organisation of the inferior alveolar nerve (IAN) were determined to confirm the microarchitecture of the IAN bundles into each of the mandibular teeth, including the composition of the mental nerve. The aim of this study was to evaluate peripheral nerve repair after the application of an antioxidant compound to the damaged nerve tissue to elevate the concentration and bioavailability of elements capable of favouring tissue repair. Twenty-five Wistar rats were divided into groups: The Control 1 (Ctl 1) (n = 5) animals had the ischiatic nerve exposed with no suture injury and were sacrificed at 30 days post-operatively. The Control 2 (Ctl 2) (n = 10) animals had the ischiatic nerve exposed, and the nerve was injured using suture in three distinct regions. In the experimental (Exp) animals (n = 10), an antioxidant organic compound was applied to the nerve injury site...(AU)


Assuntos
Pacientes , Ratos , Diagnóstico , Antioxidantes
10.
Int J Oral Maxillofac Implants ; 29(1): 63-70, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24451855

RESUMO

PURPOSE: To examine the biologic response to titanium implant surfaces treated with a neodymium:yttrium-aluminum-garnet laser. MATERIALS AND METHODS: Sixty mini-implants made of grade 2 titanium were placed in the femora of 30 Wistar rats. Thirty implants had a machined surface and the other 30 had surfaces that were roughened by laser treatment. The animals were subdivided into three groups according to bone repair periods of 15, 30, and 60 days. The samples were observed under light and electron scanning microscopes and analyzed with the Student t test. RESULTS: Formation of new bone trabeculae toward the surface was apparent for the laser-treated implants at 15 days. Thin layers of bone matrix in intimate contact with the surface in the area of the central screw threads were observed, indicating high biocompatibility. Similar results were seen with machined implants after 30 days. A significant difference in bone formation was observed between the implant types at 15 days. CONCLUSION: Bone-to-implant contact was better on the surfaces subjected to laser treatment than on the machined titanium implants. The development of new laser treatments, which promote alterations in the surface energy as well as in the macro- and microstructures of titanium, may lead to improved bone-to-implant contact and thus better outcomes.


Assuntos
Implantação Dentária Endóssea , Implantes Dentários , Lasers de Estado Sólido , Osseointegração/fisiologia , Osteogênese/fisiologia , Titânio/efeitos da radiação , Animais , Materiais Biocompatíveis/efeitos da radiação , Matriz Óssea/fisiologia , Parafusos Ósseos , Fêmur/cirurgia , Microscopia Eletrônica de Varredura , Ratos , Ratos Wistar , Propriedades de Superfície/efeitos da radiação
11.
Med Oral Patol Oral Cir Bucal ; 16(1): e124-31, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-20526271

RESUMO

OBJECTIVE: this study aimed to develop a nondecalcified bone sample processing technique enabling immunohistochemical labeling of proteins by kappa-beta nuclear factor (NF-kB) utilizing the Technovit 7200 VCR® in adult male Wistar rats. STUDY METHOD: A 1.8 mm diameter defect was performed 0.5 mm from the femur proximal joint by means of a round bur. Experimental groups were divided according to fixing solution prior to histologic processing: Group 1--ethanol 70%; Group 2--10% buffered formalin; and Group 3--Glycerol diluted in 70% ethanol at a 70/30 ratio + 10% buffered formalin. The post-surgical periods ranged from 01 to 24 hours. Control groups included a non-surgical procedure group (NSPG) and surgical procedures where bone exposure was performed (SPBE) without drilling. Prostate carcinoma was the positive control (PC) and samples subjected to incomplete immunohistochemistry protocol were the negative control (NC). Following euthanization, all samples were kept at 4°C for 7 days, and were dehydrated in a series of alcohols at -20°C. The polymer embedding procedure was performed at ethanol/polymer ratios of 70%-30%, 50%-50%, 30%-70%, 100%, and 100% for 72 hours at -20°C. Polymerization followed the manufacturer's recommendation. The samples were grounded and polished to 10-15 m thickness, and were deacrylated. The sections were rehydrated and were submitted to the primary polyclonal antibody anti-NF-kB on a 1:75 dilution for 12 hours at room temperature. RESULTS: Microscopy showed that the Group 2 presented positive reaction to NF-kB, diffuse reactions for NSPG and SPBE, and no reaction for the NC group. CONCLUSION: The results obtained support the feasibility of the developed immunohistochemistry technique.


Assuntos
Resinas Acrílicas , Osso e Ossos/anatomia & histologia , Imuno-Histoquímica/métodos , NF-kappa B , Animais , Masculino , Camundongos , Ratos , Ratos Wistar
12.
Biomed Tech (Berl) ; 53(5): 224-8, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18803528

RESUMO

Sinus floor elevation is the standard procedure that allows dental implant insertion in the atrophic posterior maxilla. Instead of autogenous bone, tissue-engineered bone grafts can be used, but clear comparative clinical studies also assessing the influence of the biomaterial are missing. In six patients, tissue-engineered bone grafts were used in eight sinus floor elevations. After culturing osteoblast-like cells from biopsies of the maxilla, they were seeded on scaffolds made either from demineralised bovine bone matrix (DBBM) or from solvent-dehydrated mineralised bone (SDBB), and grafted. In all patients primary wound healing was without complications, except for one patient in the SDBB group. After 12 months, implant insertion was possible only in the SDBB group; in the DBBM group, fibrous connective tissue was found in an attempt of implant insertion. After 5 months, implant placement was performed in one patient of each group. However, the two implants inserted in the DBBM group were lost after 6 weeks. Histology of the bone cores in the DBBM group at 5 months showed lamellar bone and osteoid, and at 12 months showed fibrous connective tissue. Inflammation and some resorption of the scaffold was found 5 months after SDBB grafting, and after 12 months cancellous bone formation encapsulating SDBB remnants were observed. These preliminary data suggest that the preparation method of the bovine bone matrix, in particular the mineral content, and therefore the mechanical stability may have some influence on the generation of new bone.


Assuntos
Materiais Biocompatíveis/química , Transplante Ósseo/métodos , Seio Maxilar/patologia , Seio Maxilar/cirurgia , Osteoblastos/transplante , Engenharia Tecidual/métodos , Adulto , Transplante Ósseo/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
13.
Ann Acad Med Stetin ; 54(1): 70-81, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19127813

RESUMO

INTRODUCTION: Alveolar bone seems to play a key role in providing support to the teeth, which are anchored to the bone by desmodontal fibers. The progressive alveolar bone resorption process occurs due to a loss of anatomic, biologic and mechanical factors. Mechanical stimulation of alveolar bone during mastication is crucial in keeping the teeth and underlying bone healthy. Tooth extraction leads to typical bone deficiency of ridge width and height of alveolar crest and reduces the possibility of placing screw titanium implants. When tooth extraction is necessary, trauma should be minimized during the procedure and bone preservation should receive careful attention. The literature has shown that early bone loss can be significantly reduced by socket grafting. The process of socket grafting requires an understanding of wound healing and an appreciation of the biological properties of the products available for socket grafting. Augmentative measures may, thus, be required to guarantee optimal prosthetic replacement of the lost tissue. Success or failure of augmentation procedures is dependent on revascularization and remodelling of the grafted bone into a vital, load bearing bone. In contrast to a visible three-dimensional change, the concept of remodelling refers to the internal turnover of bone, which is a coupled process where osteoclastic resorption and osteoblastic formation are more or less balanced. To restore alveolar bone loss and support efficient placement of dental implants, many different bone substitute such as autografts, allografts, xenografts, synthetic biomaterials and osteoactive agents have been proposed. In order to avoid harvesting an autograft, and thereby eliminating additional surgical procedures and risks, bone grafting materials and substitutes are alternative filler materials to be used for ridge augmentation. PURPOSE: To present a literature review about biomaterials applicable in alveolar ridge sockets preservation to future implants insertion. CONCLUSION: The maintenance of the dental alveolar bone after extraction depend on the attentive surgery procedure and the use of materials capable to maintain the prior space and be helpful in bone tissue healing.


Assuntos
Processo Alveolar/cirurgia , Aumento do Rebordo Alveolar/métodos , Transplante Ósseo/métodos , Animais , Reabsorção Óssea/etiologia , Reabsorção Óssea/prevenção & controle , Humanos , Extração Dentária/efeitos adversos , Perda de Dente/complicações
14.
J Biomed Mater Res A ; 84(2): 337-43, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17607762

RESUMO

The chemical and dimensional stability associated with suitable fracture toughness and propitious tribological characteristics make silicon nitride-based ceramics potential candidates for biomedical applications, mainly as orthopedic implants. Considering this combination of properties, silicon nitride components were investigated in relation to their biocompatibility. For this study, two cylindrical implants were installed in each tibia of five rabbits and were kept in the animals for 8 weeks. During the healing time, tissue tracers were administrated in the animals so as to evaluate the bone growth around the implants. Eight weeks after the surgery, the animals were euthanized and histological analyses were performed. No adverse reactions were observed close to the implant. The osteogenesis process occurred during the entire period defined by the tracers. However, this process occurred more intensely 4 weeks after the surgery. In addition, the histological analyses showed that bone growth occurred preferentially in the cortical areas. Different kinds of tissue were identified on the implant surface, characterized by lamellar bone tissue containing osteocytes and osteons, by a noncalcified matrix containing osteoblasts, or by the presence of collagen III, which may change to collagen I or remain as a fibrous tissue. The results demonstrated that silicon nitride obtained according to the procedure proposed in this research is a biocompatible material.


Assuntos
Materiais Biocompatíveis/farmacologia , Teste de Materiais , Compostos de Silício/farmacologia , Animais , Condução Óssea/efeitos dos fármacos , Remodelação Óssea/efeitos dos fármacos , Osso e Ossos/anatomia & histologia , Corantes , Feminino , Microscopia de Fluorescência , Microscopia de Polarização , Próteses e Implantes , Coelhos , Cloreto de Tolônio
15.
Ann Anat ; 188(4): 353-61, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16856600

RESUMO

Tooth eruption is a complex biological process which starts from the site of development in the jaw bone until the teeth reach their final functional position in the chewing plane. Various factors can disturb this process. Besides mechanical obstacles on the eruption path, a pathological position or axial orientation of the tooth germ, morphological aberrations of the tooth or pathological alterations of the periodontium, primary disorders of the eruption mechanism may lead to complete or partial retention of the tooth in the jaw bone. These morphological features bear upon the prognosis of orthodontic correction which is dependent upon the underlying cause. First and second molars are rarely affected by eruption disorders, with a prevalence of 0.01 to 0.08 per cent, however, marked consequences for function such as posterior open bite or elongation of the antagonists may result. Following an overview of pathogenetic factors of tooth eruption disorders, selected cases of impacted first and second permanent molars are presented with respect to their morphological causes.


Assuntos
Dentição Permanente , Dente Molar , Doenças Dentárias/patologia , Erupção Dentária , Criança , Humanos , Ortodontia Corretiva , Osteogênese , Radiografia , Doenças Dentárias/diagnóstico por imagem , Doenças Dentárias/terapia
16.
Ann Anat ; 188(2): 143-51, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16551011

RESUMO

Titanium is the ideal metal for intra-osseous dental implants. It permits the natural formation of an oxide layer on its surface and thereby it prevents the release of potentially toxic molecules. New formation of bone around implants, partially placed into the bone marrow cavity, is a gradual process that runs from the endosteum to the surface of the implant. Deposition of hydroxyapatite crystals on collagen type I fibrils is initiated by acidic proteins and leads to bone mineralization. This study analyzed the effects of hydroxyapatite upon peri-implant bone formation after insertion of smooth titanium implants. Screw-shaped smooth titanium implants of 3.75 mm thickness and 8.5 mm length were inserted into the metaphysis of rabbit tibia, either together with bovine hydroxyapatite into the right tibia or in controls without hydroxyapatite into the left tibia. Polyfluorochrome tracers (alizarin complex, calcein, tetracycline) were injected subcutaneously at different time intervals after implantation to evaluate the time frame of bone new formation over a period of 8 weeks. All samples were processed for histology and analyzed by fluorescence and polarizing microscopy. Our results showed a higher quantity of mature type I collagen fibers around implants and an acceleration of bone formation in the presence of hydroxyapatite. Mainly immature organic matrix was formed at the surface of implants in controls. The presence of hydroxyapatite seems to promote the maturation of collagen fibers surrounding the titanium implants and to support osteoconduction. Moreover, new formation of bone was faster in all samples where implants were inserted together with hydroxyapatite.


Assuntos
Desenvolvimento Ósseo/fisiologia , Remodelação Óssea/fisiologia , Osso e Ossos/fisiologia , Durapatita/uso terapêutico , Titânio/administração & dosagem , Animais , Antraquinonas/administração & dosagem , Remodelação Óssea/efeitos dos fármacos , Parafusos Ósseos , Osso e Ossos/citologia , Corantes , Implantes de Medicamento , Durapatita/administração & dosagem , Feminino , Fluoresceínas/administração & dosagem , Modelos Animais , Coelhos , Tetraciclina/administração & dosagem
17.
Ann Anat ; 188(2): 163-9, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16551014

RESUMO

Supernumerary teeth are extra teeth or toothlike structures which may have either erupted or unerupted in addition to the 20 deciduous teeth and the 32 permanent teeth. This article provides an overview of frequency, distribution and classification of supernumerary teeth. The etiology of supernumerary teeth is still unknown, yet various theories have been presented based on epidemiological studies. Four clinical cases representing the possible manifestations of supernumerary teeth are discussed.


Assuntos
Maxila/anatomia & histologia , Dente Decíduo/anatomia & histologia , Dente Supranumerário/epidemiologia , Humanos , Incidência , Prevalência
18.
J Biomed Mater Res B Appl Biomater ; 76(2): 373-80, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16184530

RESUMO

The objective of this study was to characterize calcium pyrophosphate material, evaluate its in vitro cytotoxicity, and assess its ability to induce bone formation. X-ray diffraction (XRD) was used to determine crystallinity and phases present in material. Serial dilutions of extracts, from 10-day dissolution tests in modified Eagle's medium, were exposed for 24 h to mouse fibroblasts and cytotoxicity assessed via viable staining. In vivo performance was determined by placing Ti screws with and without calcium pyrophosphate agglutinated with marrow adipose tissue in the tibiae of eight rabbits. New bone formation around test and control implants was evaluated histomorphometrically by using three fluorochrome labels: alizarin, calcein, and tetracycline. After 8 postoperative weeks, the animals were killed and specimens were retrieved and processed for fluorescence and light microscopic analysis. Calcium pyrophosphate showed no cytotoxicity and the XRD showed that the main phase of the analyzed sample corresponded to beta-calcium pyrophosphate. The largest fluorochrome labeling area occurred during the fourth and fifth postoperative weeks, in both control and experimental groups. Histologically, the bone neoformation occurred in regions where the calcium pyrophosphate was resorbed. The morphometric analysis showed implants placed with calcium pyrophosphate resulted in smaller polyfluorochrome labeling area (p < 0.05).


Assuntos
Materiais Biocompatíveis/metabolismo , Pirofosfato de Cálcio/metabolismo , Implantes Experimentais , Osseointegração , Titânio/metabolismo , Animais , Materiais Biocompatíveis/química , Transplante Ósseo , Osso e Ossos/citologia , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Pirofosfato de Cálcio/química , Feminino , Corantes Fluorescentes/metabolismo , Humanos , Teste de Materiais , Camundongos , Coelhos , Titânio/química , Difração de Raios X
19.
Implant Dent ; 13(3): 232-7, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15359159

RESUMO

Alcohol consumption affects bone metabolism by impairing osteoblast proliferation and by increasing osteoclastic activity. The purpose of this study was to evaluate bone formation in alcohol-fed rabbits following the insertion of dental titanium implants. Animals were fed with 20% ethanol sugarcane brandy pre- and postoperatively (group 1), preoperatively only (group 2), and with water as control (group 3). During the postoperative period, rabbits received doses of polyfluorochrome labels (i.e., alizarin, calcein, and tetracycline). Rabbits were killed 8 weeks after the implant insertion. The polyfluorochrome-labeled bone areas in rabbits with alcohol consumption in pre- and postoperative (group 1) and preoperatively only (group 2) were significantly less (P <.05) than in the control group (group 3). The percentage of direct bone-to-implant contact was significantly less in pre- and postoperative (49.5%) and preoperative-only (49.2%) groups than in the control group (64.7%) (P <.05). Alcoholic rabbits demonstrated significantly less bone density and direct bone-to-implant contact.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Densidade Óssea/efeitos dos fármacos , Osseointegração/efeitos dos fármacos , Análise de Variância , Animais , Implantes Dentários , Etanol/efeitos adversos , Feminino , Implantes Experimentais , Coelhos , Tíbia
20.
J Oral Maxillofac Surg ; 62(9 Suppl 2): 131-5, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15332191

RESUMO

PURPOSE: The purpose of this article is to evaluate the bone healing around 2 different dental implant surfaces after the lateralization surgery of the inferior alveolar nerve (IAN) during an 8-week healing period in rabbits, and to check if there is any interaction between the implants and the nerve. MATERIALS AND METHODS: The IAN lateralization was performed in an experimental rabbit model. Eight adult female rabbits (Oryctolagus cuniculus) underwent the surgical procedure, and 1 implant was placed on each side of the mandible while the nerve was lateralized. On both sides, the nerve was repositioned directly in contact with the implant surface. With the intention of obtaining comparative results, smooth titanium implants were installed on the right side, and blasted Al2O3 ones were placed on the left. During the healing period, bone tracers were administered subcutaneously to check different periods of bone ingrowth. RESULTS: Histologic section, regardless of the studied surface, showed bone remodeling around the nerve, without contact between the nerve and the implanted surface. The bone blocks containing implants were histomorphometrically examined through computerized analysis, and the results obtained showed that the bone remodeling around the nerve occurred during the first weeks of healing. Through analysis of variance, the blasted Al2O3 implants showed at least 2.5-fold greater bone neoformation compared with the smooth titanium implants. CONCLUSIONS: Our results showed that there was no significant difference in the healing process concerning the nerve between the 2 studied surfaces. No interaction was detected between the nerve and the implants.


Assuntos
Implantes Dentários , Mandíbula/cirurgia , Nervo Mandibular/cirurgia , Abrasão Dental por Ar , Óxido de Alumínio/química , Análise de Variância , Animais , Remodelação Óssea/fisiologia , Planejamento de Prótese Dentária , Feminino , Processamento de Imagem Assistida por Computador , Mandíbula/patologia , Nervo Mandibular/patologia , Modelos Animais , Osseointegração , Coelhos , Propriedades de Superfície , Titânio/química , Cicatrização/fisiologia
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