RESUMEN
Guided bone regeneration relies primarily on four principles--exclusion of unwanted tissues and cells, space creation and maintenance, protection of the underlying blood clot, and wound stabilization. For successful bone regeneration to occur, large bony defects require an underlying grafting material and a cell-occlusive membrane. The learning objective of this article is to review the history and principles of guided bone regeneration and describe the characteristics of a slowly resorbing bilayer collagen membrane, well suited for bone regeneration procedures. An osteoconductive bone grafting material and its ability to support the overlying collagen membrane and serve as a matrix for the ingrowth of vascular and bone-forming cells are discussed.
Asunto(s)
Implantes Absorbibles , Sustitutos de Huesos/uso terapéutico , Trasplante Óseo , Regeneración Tisular Guiada Periodontal/métodos , Membranas Artificiales , Anciano , Aumento de la Cresta Alveolar , Materiales Biocompatibles/uso terapéutico , Matriz Ósea/trasplante , Regeneración Ósea/fisiología , Colágeno/uso terapéutico , Implantes Dentales , Prótesis Dental de Soporte Implantado , Femenino , Estudios de Seguimiento , Humanos , Arcada Edéntula/rehabilitación , Arcada Edéntula/cirugía , Arcada Parcialmente Edéntula/rehabilitación , Arcada Parcialmente Edéntula/cirugía , Masculino , Persona de Mediana Edad , Minerales/uso terapéutico , Factores de Tiempo , Conservación de TejidoRESUMEN
The toothless (tl) osteopetrotic mutation in the rat is characterized by generalized skeletal sclerosis, a severe reduction in the numbers of osteoclasts, monocytes, and macrophages, and absence of tooth eruption. Studies examining gene expression in bone-derived cells of tl rats and their normal littermates have shown that genes related to osteoblast function are aberrantly expressed in tl rats compared to normal littemates. We have previously shown that exogenous administration of colony stimulating factor-1 (CSF-1) to tl rats results in a dramatic reduction of the skeletal sclerosis and significant increases in the number of osteoclasts. Thus, we examined the effects of CSF-1 on osteoblast and osteoclast gene expression in tl rats as demonstrated by Northern blot analysis. While osteoblast-related gene expression as reflected by mRNA levels of alkaline phosphatase, osteocalcin, osteopontin, and type I collagen was normalized, osteoclast-related gene expression, as reflected by mRNA levels of carbonic anhydrase II and tartrate-resistant adenosine triphosphatase, remained significantly lower in CSF-1-treated tl rats compared to untreated normal littermates. Since previous studies have not demonstrated the CSF-1 receptor on osteoblasts, these results suggest that osteoblast abnormalities in tl rats are an effect of the osteopetrotic condition rather than the cause of the disease.
Asunto(s)
Regulación de la Expresión Génica/efectos de los fármacos , Factor Estimulante de Colonias de Macrófagos/farmacología , Osteoblastos/efectos de los fármacos , Osteoclastos/efectos de los fármacos , Osteopetrosis/genética , Adenosina Difosfato/metabolismo , Fosfatasa Alcalina/genética , Fosfatasa Alcalina/metabolismo , Animales , Northern Blotting , Huesos/diagnóstico por imagen , Huesos/efectos de los fármacos , Anhidrasas Carbónicas/genética , Anhidrasas Carbónicas/metabolismo , Colágeno/genética , Colágeno/metabolismo , Modelos Animales de Enfermedad , Regulación de la Expresión Génica/genética , Histonas/genética , Histonas/metabolismo , Factor Estimulante de Colonias de Macrófagos/administración & dosificación , Factor Estimulante de Colonias de Macrófagos/uso terapéutico , Macrófagos/citología , Macrófagos/efectos de los fármacos , Monocitos/citología , Monocitos/efectos de los fármacos , Osteoblastos/citología , Osteocalcina/genética , Osteocalcina/metabolismo , Osteoclastos/citología , Osteopetrosis/patología , Osteopetrosis/fisiopatología , Osteopontina , ARN Mensajero/metabolismo , Radiografía , Ratas , Receptor de Factor Estimulante de Colonias de Macrófagos/efectos de los fármacos , Receptor de Factor Estimulante de Colonias de Macrófagos/metabolismo , Sialoglicoproteínas/genética , Sialoglicoproteínas/metabolismo , Tibia/diagnóstico por imagen , Tibia/efectos de los fármacosRESUMEN
Juvenile periodontitis is one of the more debilitating periodontal diseases. The disease entity includes two manifestations of aggressive bone destruction, a localized and a generalized form, which affect adolescents at puberty. Recent studies have defined the prevalence of the disease with regard to locale, gender, and ethnicity. In addition, significant advances have been made in evaluating host response effects in juvenile periodontitis. Studies have identified changes in cell surface receptors on neutrophils, which appear to be related to both receptor density and structure. Various molecular techniques, including restriction fragment length polymorphism, have enabled researchers to identify clonal variants of Actinobacillus actinomycetemcomitans--the microorganism most closely associated with the disease. This may prove to be very useful in identifying virulence factors that have a role in disease initiation and progression. Treatment modalities using debridement, surgery, and anti-infective therapy have been proposed for management of the disease.
