RESUMEN
(1) Background: To investigate the effect of a xenogeneic collagen matrix (CMX) seeded with autologous gingiva-derived mesenchymal cells (GMSCs) when combined with a coronally advanced flap (CAF) in the treatment of localized gingival recession type 1 (RT1). (2) Methods: Dehiscence-type defects were created in seven dogs. GMSCs were isolated, transfected with a vector carrying green fluorescent protein (GFP) and expanded. Once chronified, the defects were randomly treated with (1) CAF plus the combination of CMX and GFP+ GMSCs, (2) CAF plus CMX with autologous fibroblasts, (3) CAF plus CMX and (4) CAF alone. Histological and clinical outcomes at 2- and 6-week healing periods were analyzed and compared among groups. (3) Results: Histologically, the addition of autologous cells to the CMX resulted in reduced inflammation and a variable degree of new cementum/bone formation. CMX plus GMSCs resulted in greater mean recession reduction (1.42; SD = 1.88 mm) and percentage of teeth with recession reduction of ≥2 mm (57%) when compared to the other groups, although these differences were not statistically significant. (4) Conclusions: The histometric and clinical results indicated a positive trend favouring the combination of CMX and GMSCs with the CAF when compared to the groups without cells, although these differences were not statistically significant.
Asunto(s)
Recesión Gingival , Células Madre Mesenquimatosas , Animales , Tratamiento Basado en Trasplante de Células y Tejidos , Colágeno/uso terapéutico , Tejido Conectivo , Perros , Encía , Recesión Gingival/tratamiento farmacológico , Recesión Gingival/cirugía , Raíz del Diente , Resultado del TratamientoRESUMEN
OBJECTIVES: The purpose of this experimental in vivo investigation was to evaluate the influence of modifying the implant surface by adding a monolayer of multi-phosphonate molecules on the de novo bone formation and osseointegration. MATERIAL AND METHODS: The study was designed as an animal preclinical trial with intra-animal control and two healing periods, 2 and 8 weeks, to compare implants with an identical macro-design but with two different surfaces. Eight female Beagle dogs participated in the study. Control implants had a moderately rough surface combining sandblasting and acid etching; test implants had an additional monophosphonate layer covalently bonded to titanium. Histologic and radiographic (micro-CT) outcome variables were evaluated. RESULTS: The first bone-to-implant contact (fBIC) was located more coronally for the test implants at the first (0.065 mm (95% CI = -0.82, 0.60)) and second healing milestones (0.17 mm (95% CI = -0.9, 0.55)). Most coronal BIC of the test implants displayed a higher percentage of osseointegration, +6.33% and +13.38% after 2 and 8 weeks, respectively; however, the differences were not statistically significant. The micro-CT examination did not show any BIC difference. CONCLUSIONS: The monophosphonate layer coating demonstrated clinical, histological, and radiographic results similar to the control surface.
Asunto(s)
Implantes Dentales , Organofosfonatos , Animales , Implantación Dental Endoósea , Diseño de Prótesis Dental , Perros , Femenino , Implantes Experimentales , Oseointegración , Osteogénesis , Propiedades de Superficie , TitanioRESUMEN
OBJECTIVE: To assess the contour and volumetric changes of hard and soft tissues after guided bone regeneration (GBR) using two types of barrier membranes together with a xenogeneic bone substitute in dehiscence-type defects around dental implants. MATERIAL AND METHODS: In 8 Beagle dogs, after tooth extraction, two-wall chronified bone defects were developed. Then, implants were placed with a buccal dehiscence defect that was treated with GBR using randomly: (i) deproteinized bovine bone mineral (DBBM) covered by a synthetic polylactic membrane (test group), (ii) DBBM plus a porcine natural collagen membrane (positive control) and (iii) defect only covered by the synthetic membrane (negative control group). Outcomes were evaluated at 4 and 12 weeks. Micro-CT was used to evaluate the hard tissue volumetric changes and STL files from digitized cast models were used to measure the soft tissues contour linear changes. RESULTS: Test and positive control groups were superior in terms of volume gain and contour changes when compared with the negative control. Soft tissue changes showed at 4 weeks statistically significant superiority for test and positive control groups compared with negative control. After 12 weeks, the results were superior for test and positive control groups but not statistically significant, although, with a lesser magnitude, the negative control group exhibited gains in both, soft and hard tissues. CONCLUSIONS: Both types of membranes (collagen and synthetic) attained similar outcomes, in terms of hard tissue volume gain and soft tissue contours when used in combination with DBBM CLINICAL RELEVANCE: Synthetic membranes were a valid alternative to the "gold standard" natural collagen membrane for treating dehiscence-type defects around dental implants when used with a xenogeneic bone substitute scaffold.
Asunto(s)
Sustitutos de Huesos , Implantes Dentales , Animales , Regeneración Ósea , Sustitutos de Huesos/farmacología , Bovinos , Colágeno , Implantación Dental Endoósea , Perros , Regeneración Tisular Guiada Periodontal , Membranas Artificiales , PorcinosRESUMEN
AIM: To evaluate the safety and efficacy of autologous periodontal ligament-derived mesenchymal stem cells (PDL-MSCs) embedded in a xenogeneic bone substitute (XBS) for the regenerative treatment of intra-bony periodontal defects. MATERIAL AND METHODS: This quasi-randomized controlled pilot phase II clinical trial included patients requiring a tooth extraction and presence of one intra-bony lesion (1-2 walls). Patients were allocated to either the experimental (XBS + 10 × 106 PDL-MSCs/100 mg) or the control group (XBS). Clinical and radiographical parameters were recorded at baseline, 6, 9 and 12 months. The presence of adverse events was also evaluated. Chi-square, Student's t test, Mann-Whitney U, repeated-measures ANOVA and regression models were used. RESULTS: Twenty patients were included. No serious adverse events were reported. Patients in the experimental group (n = 9) showed greater clinical attachment level (CAL) gain (1.44, standard deviation [SD] = 1.87) and probing pocket depth (PPD) reduction (2.33, SD = 1.32) than the control group (n = 10; CAL gain = 0.88, SD = 1.68, and PPD reduction = 2.10, SD = 2.46), without statistically significant differences. CONCLUSION: The application of PDL-MSCs to XBS for the treatment of one- to two-wall intra-bony lesions was safe and resulted in low postoperative morbidity and appropriate healing, although its additional benefit, when compared with the XBS alone, was not demonstrated.
Asunto(s)
Pérdida de Hueso Alveolar , Sustitutos de Huesos , Células Madre Mesenquimatosas , Pérdida de Hueso Alveolar/diagnóstico por imagen , Pérdida de Hueso Alveolar/cirugía , Regeneración Ósea , Sustitutos de Huesos/uso terapéutico , Regeneración Tisular Guiada Periodontal , Humanos , Pérdida de la Inserción Periodontal/cirugía , Ligamento PeriodontalRESUMEN
Periodontitis is a chronic inflammatory condition leading to destruction of the tooth supporting tissues, which if left untreated may cause tooth loss. The treatment of periodontitis mainly aims to arrest the inflammatory process by infection control measures, although in some specific lesions a limited periodontal regeneration can also be attained. Current regenerative approaches are aimed to guide the cells with regenerative capacity to repopulate the lesion and promote new cementum and new connective tissue attachment. The first phase in periodontal tissue regeneration involves the differentiation of mesenchymal cells into cementoblasts to promote new cementum, thus facilitating the attachment of new periodontal ligament fibers to the root and the alveolar bone. Current regenerative approaches limit themselves to the confines of the lesion by promoting the self-regenerative potential of periodontal tissues. With the advent of bioengineered therapies, several studies have investigated the potential use of cell therapies, mainly the use of undifferentiated mesenchymal cells combined with different scaffolds. The understanding of the origin and differentiation patterns of these cells is, therefore, important to elucidate their potential therapeutic use and their comparative efficacy with current technologies. This paper aims to review the in vitro and experimental studies using cell therapies based on application of cementoblasts and mesenchymal stem cells isolated from oral tissues when combined with different scaffolds.
Asunto(s)
Cemento Dental , Periodontitis , Regeneración Ósea , Tejido Conectivo , Regeneración Tisular Guiada Periodontal , Humanos , Ligamento Periodontal , Periodoncio , RegeneraciónRESUMEN
OBJECTIVES: To study the early and late bone healing around implants placed according to a flapless immediate (test) or flapped delayed (control) implant surgical protocol. MATERIALS AND METHODS: In eight beagle dogs, immediate and delayed implants were placed. Test and control implants were randomly assigned, and horizontal and vertical bone remodelling, as well as bone-to-implant contact (BIC), were assessed with histology at 2 and 8 weeks. Teeth were used as negative controls. RESULTS: Similar results were attained in the two groups when the vertical resorption of the buccal bone crest was evaluated (approximately 0.5 mm). On the other hand, a marked horizontal buccal bone resorption was observed. Immediate implants attained a thinner buccal bone crest as compared to the delayed implant and the tooth. De novo bone formation on the implant surface appeared to be more pronounced at delayed sites at 2 weeks, whereas at 8 weeks, no difference in BIC was observed. CONCLUSIONS: Ridge alterations occurred at both implant placement protocols, with similar limited amounts of vertical buccal bone reduction and a pronounced horizontal bone reduction. The process of horizontal bone remodelling differed between the two surgical protocols.
Asunto(s)
Implantes Dentales , Alveolo Dental , Proceso Alveolar , Animales , Remodelación Ósea , Implantación Dental Endoósea , Perros , Extracción DentalRESUMEN
AIM: The objective of this in vivo experimental study to evaluate the regenerative potential of a cell therapy combining allogenic periodontal ligament-derived cells within a xenogeneic bone substitute in a similar experimental model. METHODS: In nine beagle dogs, critical size 6-mm supra-alveolar periodontal defects were created around the PIII and PIV. The resulting supra-alveolar defects were randomly treated with either 1.4 × 106 allogenic canine periodontal ligament-derived cells seeded on de-proteinized bovine bone mineral with 10% collagen (DBBM-C) (test group) or DBBM-C without cells (control group). Specimens were obtained at 3 months, and histological outcomes were studied. RESULTS: The histological analysis showed that total furcation closure occurred very seldom in both groups, being the extent of periodontal regeneration located in the apical third of the defect. The calculated amount of periodontal regeneration at the furcation area was comparable in both the test and control groups (1.93 ± 1.14 mm (17%) versus 2.35 ± 1.74 mm (22%), respectively (p = .37). Similarly, there were no significant differences in the amount of new cementum formation 4.49 ± 1.56 mm (41%) versus 4.97 ± 1.05 mm (47%), respectively (p = .45). CONCLUSIONS: This experimental study was unable to demonstrate the added value of allogenic cell therapy in supra-crestal periodontal regeneration.
Asunto(s)
Regeneración Ósea , Sustitutos de Huesos/uso terapéutico , Trasplante de Células , Defectos de Furcación/terapia , Regeneración Tisular Guiada Periodontal/métodos , Ligamento Periodontal/citología , Células Alogénicas , Animales , Modelos Animales de Enfermedad , Perros , Masculino , Trasplante HomólogoRESUMEN
OBJECTIVES: To study the hard and soft tissue volume after placing immediate (IMI) or delayed implants (DLI) with a triangular coronal macro-design (Test/T) or a conventional cylindrical design (Control/C). MATERIAL AND METHODS: T/C implants were inserted in healed ridges or in fresh extraction sockets of eight beagle dogs. Biopsies were processed for Micro-CT analysis and dental stone casts were optically scanned to obtain STL files revealing the soft tissue contours at 12 weeks. Image analysis software was utilized to match common landmarks superimposing the two sets of data. Three distinct volumes were calculated; buccal bone volume (B-BV), soft tissue volume below the implant shoulder (EC-STV), and the soft tissue volume above the implant shoulder (SC-STV). Using linear measurements, the soft tissue height (STH), the mucosal thickness (MT-IS), and the distance from the implant shoulder to the bone crest (I-BC) were assessed in the digital images and in conventional histology to assess the concordance, reproducibility, and reliability. RESULTS: There were no significant differences between test and control implants regarding the buccal bone volume, although test implants had greater B-BV in all locations except for PM2. The soft tissue volume was similar at T/C implants. The surgical approach influenced the distribution of the total tissue volume. In the IMI, a low position of the bone crest was correlated with low values of B-BV, SC-STV, MT-IS, and STH. Linear measurements showed a high correlation between the histology and digital measurements and high inter and intra examiner agreement. CONCLUSION: The superimposition of Micro-CT/STL allowed the analysis of soft and hard tissue volumes. Reduction of the implant buccal aspect resulted in nonsignificant higher bone volume although similar soft tissue volume while the surgical approach influenced soft tissue response.
Asunto(s)
Proceso Alveolar , Implantación Dental Endoósea , Implantes Dentales , Carga Inmediata del Implante Dental , Periodoncio , Animales , Perros , Proceso Alveolar/diagnóstico por imagen , Periodoncio/diagnóstico por imagen , Distribución Aleatoria , Resultado del Tratamiento , Microtomografía por Rayos XRESUMEN
AIM: To determine the histological outcomes when using a highly porous synthetic bone substitute and a cross-linked collagen membrane for lateral bone augmentation of peri-implant dehiscence defects. METHODS: In eight dogs, three treatment groups were randomly allocated at each peri-implant dehiscence defect (mean height × depth = 3 × 1 mm) as follows: (i) synthetic bone substitute covered by a cross-linked collagen membrane (test group), (ii) deproteinized bovine bone mineral covered by a natural collagen membrane (positive control), and (iii) no treatment (negative control). Two healing periods (8 and 16 weeks) were applied. RESULTS: The differences in healing outcomes between the test and positive control groups were not significant at 8 weeks. Horizontal bone augmentation 2 mm below the implant shoulder was significantly greater in the test group (1.22 ± 0.53 mm) than in the positive and negative controls (0.42 ± 0.51 and 0.36 ± 0.50 mm, respectively) at 16 weeks. Similarly, the augmented tissue thickness at 0, 1, and 2 mm apical to the implant shoulder was significantly greater in the test group than in the positive control group. CONCLUSION: The test group showed significantly better histological outcomes for lateral bone augmentation and tissue thickness at 16 weeks compared to both the positive and negative control groups.
Asunto(s)
Aumento de la Cresta Alveolar/métodos , Sustitutos de Huesos/uso terapéutico , Implantación Dental Endoósea/métodos , Regeneración Tisular Guiada Periodontal/métodos , Dehiscencia de la Herida Operatoria/cirugía , Animales , Perros , Femenino , Masculino , Extracción Dental/efectos adversosRESUMEN
AIM: To study the healing of peri-implant tissues around implants with a triangular coronal third (test) or cylindrical (control). MATERIALS AND METHODS: In eight beagle dogs, immediate and delayed implants were placed. Test and control implants were randomly assigned and the hard and soft tissue healing was evaluated with histology and micro-CT analysis at 4 and 12 weeks. The soft tissue contour changes were assessed by image analysis software. RESULTS: When measured at the implant shoulder level, the buccal crestal width (primary outcome assessed in mm) attained similar values in test and control implants. More apically (3 mm) test implants had greater buccal crestal width in delayed and immediate sites. For vertical soft and hard tissue measurements, no significant differences were found between Test and Control. Micro-CT evaluation of the buccal volume of interest showed less volume of implant component in T implants in all sites, although bone volume was not significantly different between T/C. Soft tissue contours were similar around T/C implants. CONCLUSION: Triangular implants showed similar percentage of osseointegration, buccal bone volume and soft tissue contours, although attaining greater buccal crestal bone width. No differences were found in regard to soft tissue dimensions and the position of the first bone-to-implant contact.
Asunto(s)
Proceso Alveolar/diagnóstico por imagen , Implantación Dental Endoósea/métodos , Implantes Dentales , Diseño de Prótesis Dental , Encía/diagnóstico por imagen , Animales , Perros , Humanos , Carga Inmediata del Implante Dental , Interpretación de Imagen Radiográfica Asistida por Computador , Distribución Aleatoria , Microtomografía por Rayos XRESUMEN
AIM: To evaluate histologically the healing of a xenogeneic collagen matrix (CM) used to augment the width of keratinized tissue around teeth. MATERIALS AND METHODS: The gingiva on the buccal aspect of mandibular and maxillary premolars was surgically excised on 12 minipigs. After 1 month of plaque accumulation, the resulting defects were randomly treated by a periosteal retention procedure (control site) or by placing a collagen matrix after an apically repositioned flap (CM) (test site). Clinical and histological outcomes were evaluated at 1, 4 and at 12 weeks. RESULTS: Clinically, no gain of keratinized tissue was noted in either group. Histometrically, the thickness of the gingival unit was significantly higher in the test group at 1 month, although these differences were not significant at 3 months. There was a tendency in the test group towards less bone resorption (0.7 mm) and apical displacement (0.5 mm) of the gingival margin at 3 months. CONCLUSIONS: The tested CM demonstrated uneventful healing, being resorbed within the surrounding tissues in absence of significant inflammation. When compared with periosteal retention alone, the CM group attained similar clinical and histological outcomes.
Asunto(s)
Colágeno , Encía/fisiología , Cicatrización de Heridas , Animales , Diente Premolar , Encía/citología , Xenoinjertos , Queratinas , Modelos Animales , Porcinos , Porcinos EnanosRESUMEN
AIM: To review the biological processes of wound healing following periodontal and periimplant plastic surgery when different technologies are used in a) the coverage of root and implant dehiscences, b) the augmentation of keratinized tissue (KT) and c) the augmentation of soft tissue volume. MATERIALS & METHODS: An electronic search from The National Library of Medicine (MEDLINE-PubMed) was performed: English articles with research focus in oral soft tissue regeneration, providing histological outcomes, either from animal experimental studies or human biopsy material were included. RESULTS: Barrier membranes, enamel matrix derivatives, growth factors, allogeneic and xenogeneic soft tissue substitutes have been used in soft tissue regeneration demonstrating different degrees of regeneration. In root coverage, these technologies were able to improve new attachment, although none has shown complete regeneration. In KT augmentation, tissue-engineered allogenic products and xenogeneic collagen matrixes demonstrated integration within the host connective tissue and promotion of keratinization. In soft tissue augmentation and peri-implant plastic surgery there are no histological data currently available. CONCLUSIONS: Soft tissue substitutes, growth differentiation factors demonstrated promising histological results in terms of soft tissue regeneration and keratinization, whereas there is a need for further studies to prove their added value in soft tissue augmentation.
Asunto(s)
Materiales Biocompatibles/uso terapéutico , Implantes Dentales , Péptidos y Proteínas de Señalización Intercelular/uso terapéutico , Arcada Edéntula/cirugía , Membranas Artificiales , Periodoncio/cirugía , Diente/cirugía , Regeneración Tisular Guiada Periodontal/métodos , Humanos , Queratinas , Enfermedades Periodontales/cirugía , Procedimientos de Cirugía Plástica/métodos , Ingeniería de Tejidos/métodos , Raíz del Diente/cirugía , Cicatrización de Heridas/fisiologíaRESUMEN
High entropy alloy nanoparticles are envisaged as one of the most interesting materials compared to monoatomic materials due to their modulated properties in terms of their convenient surface-to-volume ratio. However, studies are still missing to unveil how composition or nanoparticle size can influence nanoparticle morphology. Based on molecular dynamics simulations, we perform a structural characterization as a function of nanoparticle size and the chemical composition of high entropy alloy nanoparticles subject to multiple annealing cycles. After the multiple thermal loads, we observe a substantial migration of copper atoms towards the np surface, consistent with the experimental results of Cu-based high entropy alloys. The resulting high entropy alloy nanoparticle behaves as a core-shell nanostructure with a rich fcc phase on the surface (50% of Cu) and 5% fcc phase in the nanoparticle core. Inspecting the nanoparticle surface, it is observed that high entropy alloy nanoparticles have a lack of surface facets, leading to a more spherical shape, quite different from mono-metallic nanoparticles with a high number of facets. Performing an average atoms simulation, it showed that nanoparticles are prone to form 111 surface facets independent of the nanoparticle size, suggesting that for high entropy alloy nanoparticles, the chemical complexity avoids the formation of surface facets. The latter can be explained in terms of the lattice distortion inducing tensile/compressive stress that drives the surface reconstruction. All in all our results match extremely well with experimental evidence of FeNiCrCoCu nanocrystalline materials, explaining the Cu segregation in terms of surface energy and mixing enthalpy criteria. We believe that our results provide a detailed characterization of high entropy nanoparticles focusing on how chemical complexity induces morphological changes compared to mono-crystalline nanoparticles. Besides, our findings are valuable for experimental works aimed at designing the shape and composition of multicomponent nanoparticles.
Asunto(s)
Aleaciones , Cobre , Entropía , Nanopartículas del Metal , Simulación de Dinámica Molecular , Aleaciones/química , Cobre/química , Nanopartículas del Metal/química , Tamaño de la Partícula , Nanopartículas/química , Propiedades de SuperficieRESUMEN
AIM: To describe the histological and clinical outcomes of the use of a xenogeneic collagen matrix (CM) in combination with the coronally advanced flap (CAF) in the treatment of localized Miller class-I gingival recessions. MATERIAL AND METHODS: Gingival recession defects were surgically created on 12 minipigs. The defects were randomly treated with either the CAF procedure and the interposition of a CM (test) or the CAF alone (control). Clinical and histological outcomes at 1, 4 and 12 weeks were evaluated. RESULTS: Histometrically, in the test group, there was a shorter junctional epithelial dimension [2.26 (SD 0.23) mm] compared with the control [2.79 (SD 0.77) mm]. On the contrary, the amount of newly formed cementum was larger in the test group [1.08 (SD 0.41) mm] than in the control group [0.75 (SD 0.25) mm], although the differences were not statistically significant. CONCLUSIONS: Both techniques rendered similar clinical outcomes, achieving complete root coverage at the end of the study. Nevertheless, the CM graft attained more tissue regeneration, characterized by a shorter epithelium and a larger new cementum formation. The use of a xenogeneic CM resulted in the incorporation of the xenograft within the adjacent host connective tissues in the absence of significant inflammation.
Asunto(s)
Colágeno Tipo I/uso terapéutico , Tejido Conectivo/trasplante , Cemento Dental/fisiología , Recesión Gingival/cirugía , Regeneración Tisular Guiada Periodontal/métodos , Regeneración , Animales , Proteínas del Esmalte Dental/uso terapéutico , Femenino , Distribución Aleatoria , Colgajos Quirúrgicos , Porcinos , Porcinos Enanos , Andamios del TejidoRESUMEN
OBJECTIVES: To study the wound healing of acellular dermal matrix (ADM) allografts when used together with coronally advanced flaps (CAF) in the treatment of localized gingival recessions in the mini-pig experimental model. MATERIAL AND METHODS: Dehiscence defects 4 x 5 mm were surgically created in one buccal root surface in each quadrant of PI, II, or III in three mini-pigs. They were then treated with CAF and the interposition of either a connective tissue graft (CTG) or ADM. As the primary outcome, the histological interface between the ADM and the root surface was studied and was compared with CTG. As secondary outcomes, we assessed the amount and quality of the keratinized tissue and clinical outcomes in terms of root coverage and recession reduction. RESULTS: At 3 months, the CTG group attained a mean 76% root coverage, versus 62% in the ADM group. The histological interface with the root surface was similar in both groups. The apical migration of the epithelium was 1.79+/-0.46 mm for the CTG and 1.21+/-0.35 mm for ADM. Newly formed cementum was observed with both treatments. New bone and a newly formed periodontal ligament were shown in five specimens in the ADM group and in three in the CTG group. CONCLUSION: Both materials showed similar clinical and histological outcomes.
Asunto(s)
Materiales Biocompatibles/uso terapéutico , Colágeno/uso terapéutico , Recesión Gingival/cirugía , Colgajos Quirúrgicos , Proceso Alveolar/patología , Animales , Cementogénesis/fisiología , Tejido Conectivo/patología , Tejido Conectivo/trasplante , Cemento Dental/patología , Epitelio/patología , Femenino , Encía/patología , Encía/trasplante , Recesión Gingival/clasificación , Queratinas , Osteogénesis/fisiología , Ligamento Periodontal/patología , Porcinos , Porcinos Enanos , Factores de Tiempo , Raíz del Diente/patología , Trasplante Homólogo , Resultado del Tratamiento , Cicatrización de Heridas/fisiologíaRESUMEN
Root coverage in the anterior mandible is challenging due to a thin gingiva, shallow vestibule, and/or high frenulum. This case series reports on the flattening of the root surface to create a new emergence profile conceived with a two-step surgical approach aimed at providing more space for the graft, increasing the thickness of the gingival margin, and getting extra soft tissue in the open area of the recession. A total of 10 patients with recessions affecting the mandibular incisors were treated to evaluate this two-step approach, which included odontoplasty of the root followed by a connective tissue graft. At 1 year, the mean coverage was 100% in Class II recessions, and 80.5% in Class III. The mean keratinized tissue increase was 5.80 ± 1.75 mm. This surgical approach could be proposed as an alternative when treating mandibular anterior teeth with root prominence or with a buccally tilted position.
Asunto(s)
Recesión Gingival/cirugía , Incisivo , Raíz del Diente/cirugía , Adulto , Estética Dental , Femenino , Encía/cirugía , Humanos , Incisivo/cirugía , Masculino , MandíbulaRESUMEN
BACKGROUND: Periodontitis is a chronic inflammatory condition that leads to the destruction of the tooth-supporting tissues. Its treatment includes the arrest of the inflammatory process and, in some circumstances, the restoration of the lost anatomy and function, including the formation of new cementum, periodontal ligament (PDL), and bone. With this goal, we investigated the effects of low concentrations of 17beta-estradiol on human cementoblast proliferation and its possible regenerative potential in vivo. METHODS: Human cementum-derived cells obtained from a healthy human premolar were isolated and characterized by immunocytochemistry. Cell proliferation assays were performed to test the effects of 100 nM 17beta-estradiol and enamel matrix derivative (EMD). Three-wall intrabony periodontal defects were created in beagle dogs. After 1 month of plaque accumulation, 0.225 mg 17beta-estradiol impregnated in a collagen sponge was applied to randomly selected defects (test group), whereas a collagen sponge impregnated in a culture medium was applied to the control group. After 3 months, specimens were obtained, and tissue regeneration was assessed by histometric analysis. RESULTS: Cells spreading out from human tooth-layer explants were able to form cell colonies, produce a mineral matrix, and express osteocalcin, indicating they were cementoblast-like cells. In contrast, PDL fibroblasts did not express osteocalcin. 17beta-estradiol, but not EMD, increased the rate of human cementoblast cell proliferation in vitro by 2.5-fold. Histometric results from the treated periodontal defects revealed that 17beta-estradiol promoted the formation of 2.94 mm of new cementum, (45% of the defects) compared to 1.54 mm of new cementum in the control group (28% of the defects). Furthermore, the test group showed an inhibition of epithelial downgrowth and a gain of new connective tissue attachment. CONCLUSION: 17beta-estradiol promoted human cementoblast cell proliferation in vitro and periodontal regeneration in an experimental periodontitis model.
Asunto(s)
Cementogénesis/efectos de los fármacos , Cemento Dental/efectos de los fármacos , Estradiol/farmacología , Estrógenos/farmacología , Periodontitis/fisiopatología , Pérdida de Hueso Alveolar/cirugía , Animales , Técnicas de Cultivo de Célula , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Niño , Colágeno , Tejido Conectivo/efectos de los fármacos , Proteínas del Esmalte Dental/farmacología , Modelos Animales de Enfermedad , Perros , Portadores de Fármacos , Epitelio/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Regeneración Tisular Guiada Periodontal/métodos , Humanos , Masculino , Osteocalcina/análisis , Ligamento Periodontal/citología , Ligamento Periodontal/efectos de los fármacos , Periodontitis/metabolismo , Distribución Aleatoria , Regeneración/efectos de los fármacosRESUMEN
Tipo de estudio: retrospectivo, analítico, descriptivo. Objetivo: conocer cuales son las enfermedades crónicas y recurrentes más frecuentes, las enfermedades odontológicas de la infancia, el control prenatal y los factores de riesgo de la comunidad presentes en la isla Floreana, utilizando las fichas familiares del Ministerio de Salud Pública, pero modificadas. Resultados: encontramos un total de 97 personas que habitan en la isla, agrupados en 33 familias, de entre los cuales hay una embarazada sin ningún control prenatal, alta incidencia de caries en los niños; las enfermedades respiratorias agudas predominan en los menores de 15 años y las gastrointestinales en los mayores de 15 años; se encontraron 3 niños con esquema de vacunación incompleto y un buen sistema de eliminación de la basura. Conclusiones: se encontró que a pesar de tener riesgos higiénicos sanitarios altos, la mayoría de las enfermedades no son causadas por éstos; son producto del medio ambiente, malos hábitos alimenticios o a causa del tipo de trabajo. Mientras que las enfermedades crónicas de mayor riesgo como hipertensión arterial, diabetes y cáncer son mejor controladas.
Type of study: retrospective, analytic, descriptive. Objective: to know which are the chronic disease and recurrents more frequently, odontologic diseases of the childhood, prenatal control and the risk factors of the community who live in the Floreana Island, using the families card of the Department of Public Health but modificated. Results: we found a total of 97 persons that live in the island, in groups of 33 families, between them, there is a pregnant without a prenatal control, high incidence of tooth decay in children; the acute respiratory diseases predominate in younger of 15 years and gastrointestinal in older of 15 years; we found 3 children with a incomplete vaccinations and a good garbage elimination control. Conclusions: in spite of have high risk of health hygienic, the most of the diseases is not caused by this; there are produce by environment, bad food habit or jobs causes. Whereas chronic diseases of high risk like hypertension, diabetes, and cancer, there are more under control