RESUMEN
OBJECTIVES: This study assessed the bone density gain and its relationship with the periodontal clinical parameters in a case series of a regenerative therapy procedure. MATERIAL AND METHODS: Using a split-mouth study design, 10 pairs of infrabony defects from 15 patients were treated with a pool of bovine bone morphogenetic proteins associated with collagen membrane (test sites) or collagen membrane only (control sites). The periodontal healing was clinically and radiographically monitored for six months. Standardized pre-surgical and 6-month postoperative radiographs were digitized for digital subtraction analysis, which showed relative bone density gain in both groups of 0.034 ± 0.423 and 0.105 ± 0.423 in the test and control group, respectively (p>0.05). RESULTS: As regards the area size of bone density change, the influence of the therapy was detected in 2.5 mm² in the test group and 2 mm² in the control group (p>0.05). Additionally, no correlation was observed between the favorable clinical results and the bone density gain measured by digital subtraction radiography (p>0.05). CONCLUSIONS: The findings of this study suggest that the clinical benefit of the regenerative therapy observed did not come with significant bone density gains. Long-term evaluation may lead to a different conclusions.
Asunto(s)
Implantes Absorbibles , Pérdida de Hueso Alveolar/cirugía , Proteínas Morfogenéticas Óseas/uso terapéutico , Procesamiento de Imagen Asistido por Computador/métodos , Membranas Artificiales , Técnica de Sustracción , Adulto , Pérdida de Hueso Alveolar/diagnóstico por imagen , Animales , Densidad Ósea/efectos de los fármacos , Matriz Ósea/trasplante , Sustitutos de Huesos/uso terapéutico , Bovinos , Colágeno , Durapatita/uso terapéutico , Estudios de Seguimiento , Regeneración Tisular Guiada Periodontal/instrumentación , Regeneración Tisular Guiada Periodontal/métodos , Humanos , Persona de Mediana Edad , Pérdida de la Inserción Periodontal/cirugía , Bolsa Periodontal/cirugía , Radiografía de Mordida Lateral , Colgajos Quirúrgicos , Resultado del TratamientoRESUMEN
OBJECTIVES: This study assessed the bone density gain and its relationship with the periodontal clinical parameters in a case series of a regenerative therapy procedure. MATERIAL AND METHODS: Using a split-mouth study design, 10 pairs of infrabony defects from 15 patients were treated with a pool of bovine bone morphogenetic proteins associated with collagen membrane (test sites) or collagen membrane only (control sites). The periodontal healing was clinically and radiographically monitored for six months. Standardized pre-surgical and 6-month postoperative radiographs were digitized for digital subtraction analysis, which showed relative bone density gain in both groups of 0.034 ± 0.423 and 0.105 ± 0.423 in the test and control group, respectively (p>0.05). RESULTS: As regards the area size of bone density change, the influence of the therapy was detected in 2.5 mm² in the test group and 2 mm² in the control group (p>0.05). Additionally, no correlation was observed between the favorable clinical results and the bone density gain measured by digital subtraction radiography (p>0.05). CONCLUSIONS: The findings of this study suggest that the clinical benefit of the regenerative therapy observed did not come with significant bone density gains. Long-term evaluation may lead to a different conclusions.
Asunto(s)
Adulto , Animales , Bovinos , Humanos , Persona de Mediana Edad , Implantes Absorbibles , Pérdida de Hueso Alveolar/cirugía , Proteínas Morfogenéticas Óseas/uso terapéutico , Procesamiento de Imagen Asistido por Computador/métodos , Membranas Artificiales , Técnica de Sustracción , Pérdida de Hueso Alveolar , Densidad Ósea/efectos de los fármacos , Matriz Ósea/trasplante , Sustitutos de Huesos/uso terapéutico , Colágeno , Durapatita/uso terapéutico , Estudios de Seguimiento , Regeneración Tisular Guiada Periodontal/instrumentación , Regeneración Tisular Guiada Periodontal/métodos , Pérdida de la Inserción Periodontal/cirugía , Bolsa Periodontal/cirugía , Radiografía de Mordida Lateral , Colgajos Quirúrgicos , Resultado del TratamientoRESUMEN
The ultimate goal of periodontal therapy is to control periodontal tissue inflammation and to produce predictable regeneration of that part of the periodontium which has been lost as a result of periodontal disease. In guided tissue regeneration membranes function as mechanical barriers, excluding the epithelium and gingival corium from the root surface and allowing regeneration by periodontal ligament cells. This report aims to study the effect of glutaraldehyde (GA) cross-linking on mineralized polyanionic collagen (PAC) membranes by conducting a histological evaluation of the tissue response (biocompatibility) and by assessing the biodegradation of subcutaneous membrane implants in rats. We studied six different samples: a PAC, a PAC mineralized by alternate soaking processes for either 25 or 75 cycles (PAC 25 and PAC 75, respectively) and these films cross-linked by GA. Inflammatory infiltrate, cytokine dosage, fibrosis capsule thickness, metalloproteinase immunohistochemistry and membrane biodegradation after 1, 7, 15 and 30 days were measured. The inflammatory response was found to be more intense in membranes without cross-linking, while the fibrosis capsules became thicker in cross-linked membranes after 30 days. The membranes without cross-linking suffered intense biodegradation, while the membranes with cross-linking remained intact after 30 days. The cross-linking with GA reduced the inflammatory response and prevented degradation of the membranes over the entire course of the observation period. These membranes are thus an attractive option when the production of new bone depends on the prolonged presence of a mechanical barrier.
Asunto(s)
Materiales Biocompatibles , Colágeno , Reactivos de Enlaces Cruzados/química , Glutaral/química , Regeneración Tisular Guiada Periodontal , Polímeros/química , Implantes Absorbibles , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Bovinos , Colágeno/química , Colágeno/metabolismo , Regeneración Tisular Guiada Periodontal/instrumentación , Regeneración Tisular Guiada Periodontal/métodos , Implantes Experimentales , Inflamación/metabolismo , Inflamación/patología , Ensayo de Materiales , Metaloproteasas/metabolismo , Enfermedades Periodontales/metabolismo , Enfermedades Periodontales/patología , Enfermedades Periodontales/terapia , Polielectrolitos , Ratas , Ratas WistarRESUMEN
The aim of this study was to morphometrically analyze the tissue response to a customized pin obtained from devitalized bovine cortical bone (DBCB-pin) implanted in the subcutaneous tissue of rats, as well as to assess its microstructural aspect by scanning electron microscopy (SEM). The pins were implanted in the subcutaneous tissue of 20 rats, which were killed at 7, 14, 28 and 60 days (5 rats/period) after implantation. In the subcutaneous tissue, DBCB-pin promoted the formation of a fibrous capsule. At 7 days, capsule showed thickness of 70 ± 3.2 µm with higher density of newly formed capillaries and smaller density of collagen fibers. Between 14 and 60 days, more organized fibrous capsule exhibited smaller thickness (53 ± 5.5 µm) with higher density of fibroblasts and collagen fibers. In this period, a small and slow bioresorption of the DBCB-pin by macrophages and rare multinucleated giant cells without tissue damage was observed. The thickness of DBCB-pin resorbed was in mean only of 9.3 µm. During all experimental periods not occurred presence of immune reaction cells as lymphocytes and plasma cells. It was concluded that the pin derived from cortical bovine bone was well tolerated by subcutaneous tissue of rats and slowly resorbed could be an alternative material for membrane fixation in the guided tissue regeneration procedures.
Asunto(s)
Implantes Absorbibles , Materiales Biocompatibles , Pins Dentales , Regeneración Tisular Guiada Periodontal/instrumentación , Animales , Huesos , Bovinos , Implantes Experimentales , Masculino , Membranas Artificiales , Ratas , Ratas Wistar , Tejido Subcutáneo/cirugíaRESUMEN
The aim of this study was to morphometrically analyze the tissue response to a customized pin obtained from devitalized bovine cortical bone (DBCB-pin) implanted in the subcutaneous tissue of rats, as well as to assess its microstructural aspect by scanning electron microscopy (SEM). The pins were implanted in the subcutaneous tissue of 20 rats, which were killed at 7, 14, 28 and 60 days (5 rats/period) after implantation. In the subcutaneous tissue, DBCB-pin promoted the formation of a fibrous capsule. At 7 days, capsule showed thickness of 70 ± 3.2 µm with higher density of newly formed capillaries and smaller density of collagen fibers. Between 14 and 60 days, more organized fibrous capsule exhibited smaller thickness (53 ± 5.5 µm) with higher density of fibroblasts and collagen fibers. In this period, a small and slow bioresorption of the DBCB-pin by macrophages and rare multinucleated giant cells without tissue damage was observed. The thickness of DBCB-pin resorbed was in mean only of 9.3 µm. During all experimental periods not occurred presence of immune reaction cells as lymphocytes and plasma cells. It was concluded that the pin derived from cortical bovine bone was well tolerated by subcutaneous tissue of rats and slowly resorbed could be an alternative material for membrane fixation in the guided tissue regeneration procedures.
O objetivo deste estudo foi analisar morfometricamente a resposta tecidual a um pino obtido a partir de osso bovino desvitalizado cortical (DBCB pinos) implantado no tecido subcutâneo de ratos, bem como para avaliar o seu aspecto microestrutural por microscopia eletrônica de varredura (MEV). Os pinos foram implantados no tecido subcutâneo de 20 ratos, que foram sacrificados aos 7, 14, 28 e 60 dias (5 animais / período) após a implantação. No tecido subcutâneo, o pino DBCB promoveu a formação de uma cápsula fibrosa. Aos 7 dias, a cápsula apresentou espessura de 70 ± 3,2 μm com maior densidade de capilares neoformados e menor densidade de fibras colágenas. Entre 14 e 60 dias, a cápsula fibrosa apresentava-se mais organizada e exibiram menor espessura (53 ± 5,5 μm) com maior densidade de fibroblastos e fibras colágenas. Nesse período, foi observada uma bioreabsorção pequena e lenta dos pinos DBCB por macrófagos e raras células gigantes multinucleadas, sem dano tecidual. A espessura dos pinos DBCB reabsorvidos foi em média de apenas 9,3 µm. Durante todos os períodos experimentais não ocorreu presença de células como linfócitos e células plasmáticas. Concluiu-se que o pino derivado de osso bovino cortical foi bem tolerado pelo tecido subcutâneo de ratos e reabsorvido lentamente, sendo um potencial material alternativo para fixação da membrana nos procedimentos de regeneração tecidual guiada.
Asunto(s)
Animales , Bovinos , Masculino , Ratas , Implantes Absorbibles , Materiales Biocompatibles , Pins Dentales , Regeneración Tisular Guiada Periodontal/instrumentación , Huesos , Implantes Experimentales , Membranas Artificiales , Ratas Wistar , Tejido Subcutáneo/cirugíaRESUMEN
BACKGROUND: This study evaluated the influence of early removal of an expanded polytetrafluoroethylene (ePTFE) membrane on periodontal regeneration. METHODS: The third and fourth mandibular bicuspids of six healthy mongrel dogs were used. Class II furcation lesions were surgically created making lesions chronic for 21 days. Full flaps were elevated, and ePTFE membranes were adapted over the defects. The membranes were removed at 2 weeks on the experimental sides (test group [TGr]) and at 4 weeks on the control side (control group [CGr]). The dogs were sacrificed 12 weeks following placement of the membranes, and the teeth were histologically processed. Area measurements of new tissue (NT), epithelium (EP), connective tissue (CT), and new bone (NB) and linear measurements of bone height (BH) and new cementum (NC) were made. Wilcoxon signed rank test (P <0.05; N = 6) was carried out to determine differences between groups. RESULTS: The area measurements (in mm2) for TGr and CGr, respectively, were as follows: 14.32 +/- 4.01 and 12.46 +/- 3.54 (NT); 0.04 +/- 0.09 and 0.01 +/- 0.04 (EP); 2.31 +/- 2.60 and 1.91 +/- 2.96 (CT); and 9.56 +/- 3.77 and 8.79 +/- 2.99 (NB). The results of the linear measurements (in mm) for TGr and CGr, respectively, were as follows: 3.85 +/- 1.21 and 4.03 +/- 0.94 (BH) and 10.91 +/- 1.72 and 10.59 +/- 1.80 (NC). There were no statistically significant differences between TGr and CGr for any measurement. CONCLUSION: The early removal of ePTFE membranes in Class II furcation defects in dogs did not affect periodontal regeneration.
Asunto(s)
Defectos de Furcación/cirugía , Regeneración Tisular Guiada Periodontal/instrumentación , Membranas Artificiales , Politetrafluoroetileno , Regeneración/fisiología , Proceso Alveolar/patología , Animales , Densidad Ósea/fisiología , Regeneración Ósea/fisiología , Colágeno , Tejido Conectivo/patología , Cemento Dental/patología , Perros , Epitelio/patología , Defectos de Furcación/patología , Ligamento Periodontal/patología , Distribución Aleatoria , Colgajos Quirúrgicos , Factores de TiempoRESUMEN
OBJECTIVE: The aim of this study was to evaluate in an animal model the healing of degree II furcation defects treated with: an experimental barrier of resin-modified glass-ionomer cement (GIC), a polylactic acid barrier (GUI), and flap surgery (CTR). MATERIAL AND METHODS: In 3 beagles, 18 class II furcation defects were surgically produced in mandibular and maxillary premolars and exposed to plaque accumulation for 21 days. Following a full flap, notches were made at the base to the bone defect. GIC barriers were prepared immediately before use from a commercial product and fit to place with the same product. The GIC barriers were removed after 30 days and the dogs euthanized after 120 days. Histologic sections were analyzed in a computer-assisted microscope. Epithelium, new cementum with inserting fibers, and connective tissue lining the root surface in-between notches were measured and medians of percentage values calculated. RESULTS: In the GIC, epithelium constituted 3.5% (median values) of the notch-to-notch root area; new cementum was 83.6% and connective tissue 12.9%. These values were 0%, 73.6%, and 26.4% for the GUI group and 35.6%, 43.2%, and 0% for the CTR group. Bone fill median values were 54.3% for GIC, 20.6% for GUI, and 24.6% for CTR. CONCLUSION: GIC and GUI prevented epithelial migration and promoted the formation of new periodontal tissues in experimentally induced class II furcation defects in dogs.
Asunto(s)
Defectos de Furcación/cirugía , Cementos de Ionómero Vítreo , Regeneración Tisular Guiada Periodontal/instrumentación , Membranas Artificiales , Animales , Materiales Biocompatibles , Regeneración Ósea , Citratos , Tejido Conectivo/fisiología , Cemento Dental/fisiología , Perros , Epitelio/fisiología , Femenino , Proyectos Piloto , PoliésteresRESUMEN
BACKGROUND: The aim of this clinical and radiographic study was to evaluate the effect of guided tissue regeneration using a bioabsorbable barrier in the treatment of intrabony defects in humans. METHODS: Intrabony osseous defects (2 or 3 walls) around mandibular canines and premolars were treated in 10 systemically healthy patients with ages ranging from 35 to 56 years. Prior to the surgical phase, patients were enrolled in a strict maintenance program including oral hygiene instructions and scaling and root planing (presurgical Pi and GI < 10%). Patients were seen for professional prophylaxis during the duration of the study. Clinical measurements were performed with an electronic probe at baseline and at reentry 8 months following surgical therapy. Measurements included clinical attachment levels (CAL), gingival margin levels (GML), probing depths (PD), bone defect levels (BDL), and alveolar crest level (ACL). A split mouth design was used. Quadrants were randomly assigned for treatment by GTR (experimental) or open flap debridement alone (control). Standardized radiographs were taken at baseline and at reentry. Digital images were analyzed by subtraction to assess changes in area (A) and optical density (OD). Data were evaluated using paired t test. RESULTS: Statistically significant differences were found in both groups when comparing baseline and post-treatment values for CAL, GML, PD, and BDL (P < 0.0 1). Greater reductions in BDL and gain in A and OD were observed in the GTR group when compared to control (P < 0.01). Both therapies were effective in improving the clinical parameters assessed. CONCLUSION: Clinical and radiographic findings from this study demonstrated more bone fill in sites treated with GTR.
Asunto(s)
Pérdida de Hueso Alveolar/cirugía , Regeneración Tisular Guiada Periodontal , Implantes Absorbibles , Adulto , Pérdida de Hueso Alveolar/clasificación , Pérdida de Hueso Alveolar/diagnóstico por imagen , Proceso Alveolar/diagnóstico por imagen , Proceso Alveolar/patología , Diente Premolar/cirugía , Diente Canino/cirugía , Desbridamiento , Raspado Dental , Estudios de Seguimiento , Bolsa Gingival/clasificación , Bolsa Gingival/cirugía , Regeneración Tisular Guiada Periodontal/instrumentación , Humanos , Mandíbula/cirugía , Membranas Artificiales , Persona de Mediana Edad , Higiene Bucal , Pérdida de la Inserción Periodontal/clasificación , Pérdida de la Inserción Periodontal/cirugía , Bolsa Periodontal/clasificación , Bolsa Periodontal/cirugía , Proyectos Piloto , Intensificación de Imagen Radiográfica , Aplanamiento de la Raíz , Método Simple Ciego , Estadística como Asunto , Técnica de Sustracción , Colgajos QuirúrgicosRESUMEN
The applicability of endosseous implants is directly related to the topography and quality of the patient's residual bone. Several techniques have tried to expand the applicability through implant design alterations and surgical techniques for bone augmentation. This article describes an implant-induced bone expansion procedure that facilitates the placement of implants in atrophic alveolar ridges. This procedure expands the cortical plates of the alveolar ridges with or without fracture using wedge-shaped implants and the principles of guided tissue regeneration. The use of implants of larger diameters and the remodeling of the ridge external contour can be achieved with this procedure.
Asunto(s)
Proceso Alveolar/patología , Implantación Dental Endoósea/métodos , Implantes Dentales , Maxilares/patología , Osteotomía/métodos , Proceso Alveolar/fisiopatología , Proceso Alveolar/cirugía , Atrofia , Remodelación Ósea/fisiología , Resorción Ósea/fisiopatología , Resorción Ósea/cirugía , Implantación Dental Endoósea/instrumentación , Diseño de Prótesis Dental , Estudios de Seguimiento , Gingivoplastia , Regeneración Tisular Guiada Periodontal/instrumentación , Regeneración Tisular Guiada Periodontal/métodos , Humanos , Maxilares/fisiopatología , Membranas Artificiales , Procedimientos Quirúrgicos Ortognáticos , Osteotomía/instrumentación , Propiedades de Superficie , Colgajos Quirúrgicos , Cicatrización de HeridasRESUMEN
The purpose of this study was to evaluate, by histometric analysis, re-osseointegration following treatment of ligature-induced peri-implantitis in dogs. Five dogs were used in this study. Their mandibular premolars (P2, P3 and P4) were first removed. After 3 additional months of healing, two titanium implants were placed on each side of the mandible. After 3 months, the abutment connection was performed and experimental peri-implantitis was induced by placing cotton ligatures in a submarginal position. Ligatures and abutments were removed after one month and the peri-implant bone defects were randomly assigned to one of the treatments: debridement, debridement plus guided-bone regeneration, debridement plus mineralized-bone graft, and debridement plus guided-bone regeneration associated with mineralized-bone graft. Five months post-treatment, the degree of bone contact with the implant surface and the bone area within the threads were measured in 12 threads, the 6 most coronal at each side of each implant. One-way analysis of variance did not reveal statistically significant differences between the treatment modalities (p > 0.05). Within the limits of the present study, it can be concluded that there is a limited possibility of re-osseointegration around implant surfaces previously exposed by ligature-induced peri-implantitis.
Asunto(s)
Implantación Dental Endoósea , Implantes Dentales , Regeneración Tisular Guiada Periodontal , Periodontitis/cirugía , Análisis de Varianza , Animales , Diente Premolar/cirugía , Sustitutos de Huesos/uso terapéutico , Trasplante Óseo , Desbridamiento , Pilares Dentales , Implantación Dental Endoósea/efectos adversos , Perros , Estudios de Seguimiento , Regeneración Tisular Guiada Periodontal/instrumentación , Regeneración Tisular Guiada Periodontal/métodos , Ligadura/efectos adversos , Mandíbula/patología , Mandíbula/cirugía , Membranas Artificiales , Minerales/uso terapéutico , Oseointegración , Politetrafluoroetileno , Distribución Aleatoria , Propiedades de Superficie , Titanio , Extracción Dental , Cicatrización de HeridasRESUMEN
BACKGROUND: The goal of this investigation was to compare, histologically and histometrically, the healing process of dehiscence-type defects treated by guided tissue regeneration (GTR) with bioabsorbable polylactic acid (PLA) membranes and non-resorbable expanded polytetrafluoroethylene (ePTF) membranes. METHODS: Six mongrel dogs were used. Buccal osseous dehiscences were surgically created on the distal roots of the mandibular third and fourth premolars. The defects were exposed to plaque accumulation for 3 months. After this period, the defects were randomly assigned to one of the treatments: GTR with bioabsorbable membrane (PLA), GTR with non-resorbable membrane (ePTFE), open flap debridement (OFD), and non-treated control (NTC). After 3 months of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included: gingival recession, epithelial length, connective tissue adaptation, new cementum, and new bone area. RESULTS: A superior length of new cementum was observed in the sites treated by GTR, regardless of the type of barrier used, in comparison with OFD (P <0.05). No statistically significant differences were found between PLA and ePTFE in any of the parameters with the exception of bone area. PLA presented a greater bone area when compared to ePTFE, OFD, and NTC (P <0.05). CONCLUSIONS: Within the limits of this study, it can be concluded that both barriers are equally effective for new cementum formation. The bioabsorbable membrane may provide a greater bone area than the non-resorbable membrane.