RESUMO
The aim of the study was to compare the integration and implant stability of turned and oxidized titanium implants when placed in experimental bone defects with autogenous bone graft, BMP-2 or without adjunctive therapy. Four defects were prepared on each side of the mandible of 12 mongrel dogs five months after tooth extractions. Implants with turned and oxidized surfaces were placed in the defects. The circumferential gaps were filled with either autogenous bone grafts, a BMP-allogeneic dog mixture in a thermoplastic carrier, carrier alone or left without any treatment (control). There were no statistically significant differences between control and treated sites, neither for turned nor for oxidized implants with regard to histomorphometric measurements in ground sections and to implant stability as measured with resonance frequency analysis (RFA) after 4 and 12 weeks of healing. However, oxidized implants showed a significantly higher stability after 4 weeks and a tendency (p < 0.1) of that after 12 weeks. Histomorphometry showed more bone contacts for oxidized than for turned implants. It is concluded that oxidized implants gain stability more rapidly and integrate with more bone contacts than implants with a turned surface when placed in bone defects.
Assuntos
Proteínas Morfogenéticas Ósseas/farmacologia , Materiais Revestidos Biocompatíveis , Implantes Dentários , Planejamento de Prótese Dentária , Osseointegração/fisiologia , Fator de Crescimento Transformador beta/farmacologia , Animais , Proteína Morfogenética Óssea 2 , Regeneração Óssea/efeitos dos fármacos , Transplante Ósseo , Implantação Dentária Endóssea , Polimento Dentário , Retenção em Prótese Dentária , Cães , Implantes Experimentais , Masculino , Mandíbula/cirurgia , Osseointegração/efeitos dos fármacos , Óxidos , Estatísticas não Paramétricas , Propriedades de Superfície , Titânio , VibraçãoRESUMO
The aim of this study was to determine the biocompatibility and osteoconductive potential of a high-strength canasite glass ceramic. Glass-ceramic rods were produced using the lost-wax casting technique and implanted in the mid-shafts rabbit femurs. Implants were harvested at 4, 13 and 22 weeks and prepared for light and electron microscopy. Hydroxyapatite was used as a control material. Hydroxyapatite implants were surrounded by new mineralised bone tissue after 4 weeks of implantation. The amount of bone surrounding the implant increased slightly at 13 weeks. In contrast, canasite glass and glass ceramic implants were almost entirely surrounded by soft tissue during all the time periods. Close contact between bone and canasite glass-ceramic implant without the intervening fibrous tissue was observed in only a few regions. The canasite formulation evaluated was not osteoconductive and appeared to degrade in the biological environment. It was therefore concluded that the canasite formulation used was unsuitable for use as implant. Further work is required to improve the biocompatibility of these materials with bone tissue. It is possible that this could be achieved by reducing the solubility of the glass and glass ceramic.
Assuntos
Materiais Biocompatíveis , Cerâmica , Fêmur/metabolismo , Vidro , Implantes Experimentais , Animais , Durapatita/química , Durapatita/metabolismo , Fêmur/citologia , Teste de Materiais , Microscopia Eletrônica de Varredura , Osseointegração/fisiologia , Osteogênese/fisiologia , CoelhosRESUMO
The healing of standardized bone defects grafted with either particulate ionomeric or hydroxyapatite bone substitutes was compared in the mandibular ramus of 30 Sprague-Dawley rats. The possible additional response achieved when combining these materials with a guided bone regeneration (GBR) technique was also evaluated. Three groups of 10 animals received either no implant material or ionomeric or hydroxyapatite bone substitute in defects in the right ramus. The left mandibular defects received the same treatment, except that the operation site was covered by a membrane (GBR technique). Half of the animals were sacrificed at 4 and 10 weeks following surgery, and the inflammatory response at the implant site and the amount of new bone formed in the defects were determined histomorphometrically. Defects implanted with ionomeric bone substitute exhibited more bone formation (4 weeks = 3.19 +/- 0.35 mm2, 10 weeks = 5.35 +/- 0.26 mm2) than both defects that received no treatment (4 weeks = 0.88 +/- 0.35 mm2, 10 weeks = 2.1 +/- 0.49 mm2), membrane alone (4 weeks = 1.21 +/- 0.05 mm2) or hydroxyapatite bone substitute (4 weeks = 1.41 +/- 0.46 mm2, 10 weeks = 3.34 +/- 0.41 mm2) at 4 weeks (P < or = .01) and at 10 weeks (P < or = .05). The use of a GBR technique did not increase the amount of bone formed, compared to the use of bone substitutes alone. Hydroxyapatite and ionomeric bone substitutes used alone were more effective in inducing repair of the defects than was GBR membrane alone. The use of hydroxyapatite was associated with a greater inflammatory reaction (P < or = .01) than was ionomer in this model.
Assuntos
Regeneração Óssea , Substitutos Ósseos , Próteses e Implantes , Análise de Variância , Animais , Durapatita , Cimentos de Ionômeros de Vidro , Regeneração Tecidual Guiada/métodos , Masculino , Mandíbula/cirurgia , Ratos , Ratos Sprague-Dawley , Estatísticas não Paramétricas , CicatrizaçãoRESUMO
Hemangioendothelioma is a relatively uncommon tumor of the oral cavity. This article reviews the literature on hemangioendothelioma and presents one additional case of this neoplasm found on the lip.
Assuntos
Hemangioendotelioma , Neoplasias Labiais , Adulto , Hemangioendotelioma/patologia , Hemangioendotelioma/cirurgia , Humanos , Neoplasias Labiais/patologia , Neoplasias Labiais/cirurgia , MasculinoRESUMO
The authors report 4 cases of accidental dislodgement of teeth to adjacent anatomical areas during extraction. The causes and their prevention are discussed and solutions for the problem are suggested.
Assuntos
Migração de Corpo Estranho/etiologia , Doença Iatrogênica , Complicações Intraoperatórias , Dente Serotino/cirurgia , Extração Dentária/efeitos adversos , Adolescente , Adulto , Feminino , Humanos , Masculino , Reoperação , Dente Impactado/cirurgiaRESUMO
The pain and swelling resulting from impacted lower third molars surgery were investigated in 18 patients. A descriptive pain scale method and paracetamol consumption were used for pain evaluation. The face bow nine-pointers was used for swelling measurements. The results showed that the pain peaked at 3 post-operative hours when it was considered of moderate intensity and decreased considerably in the following periods. Swelling peaked between 32 and 48 hours after surgery, and thereafter, a tendency towards regression was observed. No corelationship was found between pain symptoms and swelling.