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INTRODUCTION: Although there are therapeutic options for the treatment of oral mucosa defects, the need for functional, anatomical and aesthetically similar substitutes persists, as well as for solutions to reduce autologous grafts morbidity. OBJECTIVE: To determine clinical and histological compatibility of equivalent oral mucosa allografts generated through tissue engineering in non-consanguineous rats. MATERIALS AND METHODS: We used a sample of oral mucosa from Sprague Dawley rats to obtain a fibroblast culture and a keratinocytes and fibroblasts co-culture. In both cases, we used a commercial collagen membrane as "scaffold". After ten weeks of culture, we grafted the resulting membranes into four Wistar rats. The first phase of the study was the development of the oral mucosa equivalents generated by tissue engineering. Then, we implanted them in immunocompetent Wistar rats, and finallywe evaluated the clinical and histological features of the allografts. RESULTS: In vivo evaluation of mucosal substitutes showed a correct integration of artificial oral mucosa in immunocompetent hosts, with an increase in periodontal biotype and the creation of a zone with increased keratinization. Histologically, the tissue was similar to the control oral mucosa sample with no inflammatory reaction nor clinical or histological rejection signs. CONCLUSION: The equivalent oral mucosa allografts generated by tissue engineering showed clinical and histological compatibility.

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Resumen Introducción: A pesar de que existen opciones terapéuticas para el tratamiento de defectos de la mucosa bucal, persiste la necesidad de encontrar sustitutos funcionales, anatómicos y estéticamente similares al tejido que se va a reemplazar, así como soluciones que reduzcan la morbilidad de los injertos autólogos. Objetivo: Determinar la compatibilidad clínica e histológica de aloinjertos equivalentes de mucosa bucal elaborados mediante ingeniería tisular en ratas no consanguíneas. Materiales y métodos: Se utilizó una muestra de mucosa bucal de ratas Sprague Dawley para la obtención de un cultivo de fibroblastos y otro de queratinocitos y fibroblastos. En ambos casos, se usó una membrana de colágeno comercial como soporte. Después de diez semanas de cultivo, las membranas resultantes se injertaron en cuatro ratas Wistar. La primera fase del estudio consistió en la elaboración de los tejidos análogos de mucosa bucal mediante ingeniería tisular, los cuales se implantaron en ratas Wistar inmunocompetentes; posteriormente, se evaluaron las características clínicas e histológicas del aloinjerto. Resultados: La evaluación in vivo de los tejidos análogos demostró que se habían integrado correctamente en los huéspedes inmunocompetentes, y se había logrado el aumento del biotipo periodontal y la creación de una zona con mayor queratinización. Desde el punto de vista histológico, el tejido adquirió características similares a las de la muestra de mucosa bucal de control, sin ningún tipo de reacción inflamatoria ni signos clínicos o histológicos de rechazo. Conclusión: Hubo compatibilidad clínica e histológica de los aloinjertos equivalentes de mucosa bucal obtenidos mediante ingeniería tisular.

Abstract Introduction: Although there are therapeutic options for the treatment of oral mucosa defects, the need for functional, anatomical and aesthetically similar substitutes persists, as well as for solutions to reduce autologous grafts morbidity. Objective: To determine clinical and histological compatibility of equivalent oral mucosa allografts generated through tissue engineering in non-consanguineous rats. Materials and methods: We used a sample of oral mucosa from Sprague Dawley rats to obtain a fibroblast culture and a keratinocytes and fibroblasts co-culture. In both cases, we used a commercial collagen membrane as "scaffold". After ten weeks of culture, we grafted the resulting membranes into four Wistar rats. The first phase of the study was the development of the oral mucosa equivalents generated by tissue engineering. Then, we implanted them in immunocompetent Wistar rats, and finally we evaluated the clinical and histological features of the allografts. Results: In vivo evaluation of mucosal substitutes showed a correct integration of artificial oral mucosa in immunocompetent hosts, with an increase in periodontal biotype and the creation of a zone with increased keratinization. Histologically, the tissue was similar to the control oral mucosa sample with no inflammatory reaction nor clinical or histological rejection signs. Conclusion: The equivalent oral mucosa allografts generated by tissue engineering showed clinical and histological compatibility.

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Objetivo: determinar la actividad de un injerto basado en el cocultivo de fibroblastos gingivales y queratinocitos en membrana de colágeno comercial Mem-Lok(R) (BioHorizons), Alabama, Estados Unidos) en el tratamiento de recesiones gingivales. Materiales y métodos. Esta investigación fue descriptiva y de diseño experimental. La muestra se conformó de 10 ratas Sprague Dawley a las que se indujeron recesiones gingivales. A 8 de ellas se les aplicó el injerto y las 2 restantes no recibieron tratamiento. Resultados: el análisis descriptivo de los resultados determinó la posibilidad de obtener un cocultivo celular. Luego de la aplicación del injerto, las características clínicas periodontales indicaron salud, consistencia firme, textura a manera de puntillado, contorno festoneado, biotipo grueso, sondaje periodontal de 1 mm y posición de la encía a nivel del límite amelocementario. Conclusiones: el injerto aplicado logró una cobertura radicular del 100 por ciento en todos los casos. No se observó sangrado ni contracción cicatrizal.

Aim: to determine the effectiveness of a graft based onco-cultivation of gingival fibroblast and keratinocytes in commercial collagen membrane Mem-Lok® (BioHorizons, Alabama,USA) in the treatment of gingival recessions. Materials and methods: This research was descriptiveand experimental in design. The sample was composed of 10 Sprague Dawley rats which were induced gingival recession; two of them were not treated and the graft was applied in eightof them. Results: A descriptive analysis of the results was performed, which showed that it was possible to obtain a cellco-culture. After the application of the graft, clinical periodontal characteristics were observed that indicated health: the consistency was firm, the texture resembled dots, scallopedand knife edge margin, a thick biotype and the depth ofgingival sulcus was 1 mm. Conclusions: The applied graft achieved a 100% radicularcoverage in all cases and no bleeding or scar contractionwas observed.

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Introducción: la caries dental es considerada un problema de salud pública, para su tratamiento se han propuesto diversos biomateriales, entre ellos el uso de la mezcla de fluoruro+nitrato de plata, llamada Fluoruro Diamino de Plata (FDP) con propiedades cariostáticas, remineralizantes y bactericidas utilizado en dientes primarios. Son pocos los estudios que valoran la respuesta del tejido dentario luego de aplicarlo, es por ello que el objetivo de este estudio fue determinar el efecto del FDP en caries inducidas en ratas Wistar. Métodos: se hizo inducción de caries dental en molares de ratas Wistar, inoculándolos con S. mutans CVCM656, manteniendo dieta rica en sacarosa durante 12 semanas. Diagnosticadas las caries y distribuidas en grupos control (C1,C2) y experimental (E1,E2), se removió dentina reblandecida de los molares y se topificaron con FDP al 3,8% solo los molares de los grupos experimentales. Finalmente se hizo valoración clínica y toma de muestra para estudio histológico a las 7 y 13 semanas posteriores al tratamiento. Resultados: los grupos control registraron aumento del número de lesiones cariosas y progresión de su severidad, mientras que los grupos experimentales no revelaron cambios en estos parámetros, mostrando superficies dentinarias duras y oscuras, el reporte histológico determinó aumento en el espesor de predentina únicamente en los molares de los grupos experimentales. Conclusiones: el protocolo de inducción de caries en ratas Wistar fue exitoso; asimismo, el tratamiento con FDP inactivó los procesos cariosos sin que progresaran en severidad ni aumentara el número de caries, siendo estos resultados extrapolables a los humanos.

Introduction: dental caries is considered a public health problem. Various biomaterials have been suggested for treating it, including fluride+silver nitrate mix, known as silver diamine fluoride (SDF) which contains cariostatic, remineralizing, and bactericide properties and is used on primary teeth. Only a few studies have assessed the response of dental tissue when this substance is applied; the objective of this study was therefore to determine the effect of SDF on caries induced in Wistar rats. Methods: dental caries was induced in Wistar rats’ molars by inoculating them with S. mutans CVCM656 and feeding them a sucrose-rich diet for 12 weeks. Once caries were diagnosed and sorted out into control groups (C1, C2) and experimental groups (E1, E2), softened dentine was removed from molars; only the molars from experimental groups received a topical application of 3.8% SDF. Finally, clinical assessment was performed and samples were collected for histological study 7 and 13 weeks after treatment. Results: the control groups experienced an increased number of carious lesions and progression in severity, while the same parameters in the experimental groups remained unchanged, showing hard dark dentine surfaces. The histological report showed increased predentine thickness in molars from the experimental groups only. Conclusions: the protocol of caries induction in Wistar rats was successful. Treatment with SDF deactivated the carious processes, arresting not only severity progression but also the increase in number of caries; these findings may be extrapolated to humans.

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