Although the search for the ideal bone substitute has been the focus of a large number of studies, autogenous bone is still the gold standard for the filling of defects caused by pathologies and traumas, and mainly, for alveolar ridge reconstruction, allowing the titanium implants installation. OBJECTIVES: The aim of this study was to evaluate the dynamics of autogenous bone graft incorporation process to surgically created defects in rat calvaria, using epifluorescence microscopy. MATERIAL AND METHODS: Five adult male rats weighing 200-300 g were used. The animals received two 5-mm-diameter bone defects bilaterally in each parietal bone with a trephine bur under general anesthesia. Two groups of defects were formed: a control group (n=5), in which the defects were filled with blood clot, and a graft group (n=5), in which the defects were filled with autogenous bone block, removed from the contralateral defect. The fluorochromes calcein and alizarin were applied at the 7th and 30th postoperative days, respectively. The animals were killed at 35 days. RESULTS: The mineralization process was more intense in the graft group (32.09%) and occurred mainly between 7 and 30 days, the period labeled by calcein (24.66%). CONCLUSIONS: The fluorochromes showed to be appropriate to label mineralization areas. The interfacial areas between fluorochrome labels are important sources of information about the bone regeneration dynamics.

OBJECTIVE: The aim of this study was to compare two methodologies used in the evaluation of tissue response to root-end filling materials in rats. MATERIAL AND METHODS: Forty rats were divided into 4 groups: in Groups I and II (control groups), empty polyethylene tubes were implanted in the extraction site and in the subcutaneous tissue, respectively; in Groups III and IV, polyethylene tubes filled with ProRoot MTA were implanted in the extraction site and in the subcutaneous tissue, respectively. The animals were killed 7 and 30 days after tube implantation, and the hemi-maxillas and the capsular subcutaneous tissue, both with the tubes, were removed. Specimens were processed and evaluated histomorphologicaly under light microscopy. The scores obtained were analyzed statistically by the Kruskal-Wallis test (p<0.05). RESULTS: There were no statistically significant differences between the implantation methods (p=0.78033, p=0.72039). It was observed that the 30-day groups presented a more mature healing process due to smaller number of inflammatory cells. CONCLUSIONS: The present study showed no differences in tissue responses as far as the implantation site and the studied period were concerned. Alveolar socket implantation methodology represents an interesting method in the study of the biological properties of root-end filling endodontic materials due to the opportunity to evaluate bone tissue response.

Although the use of periodontal dressings is currently limited, there are some indications for their use. Selection of any material that will have direct contact with live tissues, such as periodontal dressings, should be careful in order to allow surgical wound healing. The aim of this study was to evaluate the intensity of inflammatory response and bone formation in tooth sockets of rats after implantation of three periodontal dressings. After removal of the right maxillary incisors of 84 male rats, each tooth socket received implantation of a polyethylene tube, 63 of which were filled with non-eugenol periodontal dressing and the remaining 21 tubes remained empty (control group). Histological evaluation assessed the intensity of inflammatory response and presence and location of bone tissue formation at postoperative periods of 7, 14 and 28 days. Statistical analysis was performed by the Kruskal-Wallis test at 5% significance level. Regarding the inflammatory infiltrate, at 28 days, there was statistically significant difference between one of periodontal dressings and control group (p<0.05). Analysis of postoperative periods, showed that the control group presented statistically significant reduction in the inflammatory infiltrate comparing the 14- and 28-day periods (p<0.05). Regarding bone tissue formation, there was difference in control group between the 7- and 28-day periods (p<0.05). Within the experimental conditions, it may be concluded that no differences were found in the inflammatory response among the groups at 7 and 14 days and that Voco pacTM dressing induced a more intensive inflammatory reaction at 28 days.

Estudios han demostrado la capacidad del hipoclorito de sodio en la remoción del ligamento periodontal sin vitalidad en dientes avulsionados. Sin embargo el uso de esta sustancia puede ocasionar un efecto irritante en el tejido conjuntivo. Siendo así adecuaciones en su utilización se muestran necesarias para que se obtenga un reparo más satisfactorio cuando utilizados en dientes reimplantados. Por lo tanto es propuesta de ese estudio evaluar la capacidad de remoción del ligamento periodontal, por medio de fricción de la superficie radicular de dientes de ratones, con una gasa humedecida en solución de hipoclorito de sodio al 1%. Fueron utilizados 40 dientes divididos en 4 grupos de 10, los cuales después de la extracción, fueron mantenidos en medio seco por 60 minutos. En el grupo control, los dientes fueron mantenidos en 25ml de hipoclorito de sodio a 1% por 5 minutos. En el grupo II, la superficie radicular fue friccionada con gasa humedecida en 25ml de solución de hipoclorito de sodio a 1% por un periodo de 1 minuto y en la secuencia lavados en suero fisiológico por 4 minutos. En el grupo III, la fricción fue de 2 minutos, y el periodo del lavado 2 minuto. En el grupo IV, la fricción con 4 minutos y el periodo del lavado 1 minuto. Después del procesamiento laboratorial, los cortes obtenidos fueron coloreados por el Tricromio de Masson y Hematoxilina y eosina para análisis en microscopia de luz. Los resultados demostraron que en el grupo control 100% de la superficie radicular estaba cubierto por ligamento periodontal. A través del test de proporción, se observó que la fricción por 1 minuto fue menos eficaz, con diferencia estadísticamente significante (p<0,0001). La remoción por completo del ligamento periodontal se obtuvo solamente en los periodos de 2 y 4 minutos

Studies have demonstrated the capacity of the sodium hypochloride in removing the non-vital periodontal ligament in avulsed tooth. Adequacies in its use are necessary to get a repair more satisfactory when teeth are replanted. Therefore, the purpose of this study was to evaluated the capacity of removal the periodontal ligament in root surface of rats, using friction of sodium hypochloride 1% solution absorbed gauze. Forty teeth were divided in 4 groups with 10 teeth, which after the extration, had been kept in dry way per 60 minutes. In control group, the teeth had been kept in 25ml of sodium hypochloride 1% for 5 minutes. In group II, the root surface was rubbed with in 25ml of sodium hypochloride 1% solution absorbed gauze for 1 minute and rinsed for 4 minutes in saline. In group III, the friction was of 2 minutes, and the rinsed period was of 3 minutes. In the group IV, the friction was of 4 minutes and the rinsed period was of 1 minute. After laboratorial processing, the specimens had been colored by the Masson tricromic and Hematoxilin and eosin for microcopy evaluation. The results had demonstrated that in the control group 100% of the root surface was covered by periodontal ligament. By means of the ratio test, it was observed that the friction per 1 minute was less efficient, being statistically significant (p<0,0001). The complete removal of the periodontal ligament it was only gotten in the period of 2 and 4 minutes.

Sabe-se que o hipoclorito de sódio pode remover o ligamento periodontal desvitalizado em dentes avulsionados. Adequações em seu uso se mostram necessárias para se obter um reparo mais satisfatório em dentes reimplantados. Portanto, estudou-se neste trabalho a capacidade de remoção do ligamento periodontal, por meio de fricção da superfície radicular de dentes de rato, com uma gaze embebida em solução de hipoclorito de sódio a 1%. Foram utilizados 40 dentes divididos em 4 grupos de 10, os quais após a extração, foram mantidos em meio seco por 60 minutos. No grupo controle, os dentes foram mantidos em 25ml de hipoclorito de sódio a 1% por 5 minutos. No grupo II, a superfície radicular foi friccionada com gaze embebida em 25ml de solução de hipoclorito de sódio a 1% por um período de 1 minuto e na seqüência lavados em soro fisiológico por 4 minutos. No grupo III, a fricção foi de 2 minutos, e o período de lavagem foi de 3 minutos. No grupo IV, a fricção foi de 4 minutos e o período de lavagem foi de 1 minuto. Após o processamento laboratorial, os cortes foram corados pelo Tricrômico de Masson e pela hematoxilina e eosina para análise histomorfométrica. Os resultados demonstraram que no grupo controle, 100% da superfície radicular estava coberta por ligamento periodontal. Mediante o teste de proporção, observou-se que a fricção por 1 minuto foi menos eficaz, sendo estatisticamente significante (p<0,0001). A remoção completa do ligamento periodontal foi obtida somente nos período de 2 e 4 minutos.

Foi estudada histologicamente a reparação do alvéolo dental de ratos desidratados, após o implante de adesivo fibrínico (TISSUCOL®) associado à irrigação prévia da ferida com solução a 5% de ácido épsilon-aminocapróico. Foram empregados 72 ratos, divididos em três grupos, que receberam diferentes tratamentos após o procedimento cirúrgico. No Grupo I, após a extração do incisivo superior direito, a mucosa gengival foi suturada. Nos Grupos II e III foi provocada a desidratação crônica pela privação de ingestão de líquidos durante 09 dias (3 dias no pré-operatório e 6 dias no pós-operatório), sendo que, no Grupo II, após a extração dental, a mucosa gengival foi suturada de forma semelhante à do Grupo I; no Grupo III, logo após a exodontia, o alvéolo foi irrigado com a solução de ácido épsilon-aminocapróico a 5%, seguida de implante de adesivo fibrínico (TISSUCOL®) e foi feita sutura da mucosa de forma semelhante à dos demais grupos. Decorridos 3, 7, 15 e 21 dias após o ato operatório, os animais foram sacrificados em número de 6 para cada grupo. A seguir, as peças contendo o alvéolo dental foram removidas e fixadas em formalina a 10% e descalcificadas em solução de ácido fórmico e citrato de sódio em partes iguais. Após processamento laboratorial de rotina, foram incluídas em parafina para microtomia. Foram obtidos cortes semi-seriados com 6 micrômetros de espessura, seguidos de coloração em hematoxilina e eosina para estudo microscópico. Os resultados obtidos mostram que a hidroprivação no pré e pós-operatório ocasiona profundo retardo no processo de reparo em feridas de extração dental. O emprego de adesivo fibrínico (TISSUCOL®) melhora o quadro fibrinolítico provocado pela desidratação.

A histological study was conducted of the alveolar bone healing process following tooth extraction of dehydrated rats after the implantation of fibrin adhesive (TISSUCOL™) associated to previous irrigation of the wound with a 5% epsilon aminocaproic acid solution (EACA). Seventy two rats were used, divided into three groups receiving different treatments after the surgical procedure. In group I, the gingival mucosa was sutured after extraction of the right upper incisor. In groups II and III, chronic dehydration was produced by water deprivation for 9 days (3 days in the preoperative period and 6 days in the postoperative period). In the animals of Group II, after tooth extraction, the gingival mucosa was sutured in the same way as performed in group I. In group III, after extraction, the dental socket was irrigated with 5% EACA, followed by implantation of the fibrin adhesive (TISSUCOL™). The mucosa was sutured in the same way as performed in the other groups. At 3, 7, 15 and 21 postoperative days, the animals were sacrificed in number of 6 for each group. Specimens containing the dental socket were removed and fixed in 10% formalin and decalcified in an equal part formic acid and sodium citrate solution. After routine processing, the specimens were embedded in paraffin for microtomy. We obtained 6 µm semi-serial slices that were stained with hematoxylin and eosin for histological evaluation. The results showed that the water deprivation in the pre- and postoperative periods caused a delay in the alveolar bone healing process. The use of the fibrin adhesive (TISSUCOL™) produced an improvement in the fibrinolytic picture caused by dehydration.