Prevalencia de cristales de colesterol en granulomas perirradiculares de origen endodóntico / Prevalence of cholesterol crystals in periradicular granulomas of endodontic origin

Objetivos: Identificar y determinar la prevalencia de cristales de colesterol (CRCo) en granulomas perirradiculares de origen endodóntico y el tipo de reacción que provocan en los tejidos circundantes. Material y métodos: Se estudiaron con microscopía óptica 75 preparados histológicos de archivo pertenecientes a lesiones perirradiculares humanas correspondientes a piezas dentarias que habían recibido un tratamiento endodóntico pre- vio y que, según los informes que acompañaban las muestras, habían sido obtenidas mediante una apicectomía. Del total, 68 muestras fueron diagnosticadas como granulomas, mientras que los 7 restantes se diagnosticaron como quistes inflamato- rios y fueron descartadas. Resultados: 39 granulomas pertenecían a pacientes de sexo femenino con presencia de CRCo en el 58,97% de los ca- sos. Los 29 granulomas restantes pertenecían al sexo mascu- lino y presentaron CRCo en un 41,37%. La mayor proporción de CRCo fue hallada en granulomas pertenecientes a pacien- tes mayores de 62 años. Los CRCo se observaron rodeados de macrófagos y células gigantes multinucleadas, provocando una reacción a cuerpo extraño. También se observaron células espumosas en áreas circundantes. Conclusiones: La presencia de CRCo en granulomas perirradiculares de origen endodóntico provoca una reacción a cuerpo extraño que puede interferir con el proceso de re- paración posendodóntico especialmente en pacientes de edad avanzada (AU)

Aim: Identify and determine the prevalence of cholester- ol crystals (CRCo) in periradicular granulomas of endodontic origin and the type of reaction they produce in the surround- ing tissues. Material and methods: 75 archival histological preparations were studied with optical microscopy. They be- longed to human periradicular lesions corresponding to teeth that had received a previous endodontic treatment and that, according to the reports accompanying the samples, had been obtained by an apicoectomy. Of the total, 68 samples were diagnosed as granulomas, while the remaining 7 were diag- nosed as inflammatory cysts and were discarded. Results: 39 granulomas corresponded to female patients in which the presence of CRCo was observed in 58.97% of the cases. The remaining 29 granulomas were from male patients and showed CRCo in 41.37% of the cases. The highest pro- portion of CRCo was found in patients over 62 years of age. The CRCo were surrounded by macrophages and multinucle- ated giant cells causing a foreign body reaction. Foam cells were also observed in the surrounding areas. Conclusions: The presence of CRCo in periradicular granulomas of endodontic origin could be a factor interfering with periapical healing after conventional endodontic thera- py, especially in elderly patients (AU)

Prevalencia de cristales de colesterol en granulomas perirradiculares de origen endodóntico / Prevalence of cholesterol crystals in periradicular granulomas of endodontic origin

Resumen Objetivo Comparar dos procedimientos de soldadura convencionales empleando una aleación de Cr-Co, para conectar barras coladas seccionadas a ser fijadas sobre implantes. Materiales y métodos A partir de un modelo maestro que representa un maxilar desdentado con cuatro implantes, se confeccionaron veinte (n=20) probetas seccionadas en tres partes. Se conformaron dos grupos, cada uno con diez (n=10) ejemplares. Una vez acondicionadas, fueron atornilladas al modelo maestro. Su desajuste inicial se analizó utilizando una lupa estereoscópica, con una cámara incorporada y un software. Las partes fueron soldadas empleando un procedimiento diferente para cada grupo. Las correspondientes al Grupo I se invistieron en un block refractario a base de sílico-fosfato. Las del Grupo II se montaron en una estructura metálica Clever Spider. El desajuste fue mensurado y los resultados procesados estadísticamente. El nivel de significación fue establecido en p<0,05. Resultados El Grupo I tuvo un desajuste inicial de 97,30±13,81μm y el Grupo II de 98,53±11,24μm. Luego de la soldadura, el Grupo I registró 98,53±17,17μm, 1,23μm mayor respecto al inicial. En el Grupo II se observó 103,13±17,61μm, 4,60μm por encima del original. Se analizaron mediante prueba t de Student; en ambos casos el resultado fue de p>0,05. Al comparar entre sí los grupos I y II, por medio de la prueba t y de comprobación no paramétrica de Mann-Whitney, se observaron diferencias no significativas, p=0,41 y p=0,38 respectivamente. Conclusiones Bajo las condiciones de este estudio, se observó que los dos métodos de soldadura analizados fueron confiables para unir supraestructurasos metálicas sin que se afecte su ajuste final.

Abstract Aim Compare two conventional welding procedures using a Cr-Co alloy, to connect sectioned cast bars to be fixed on implants. Materials and methods From a master model representing a toothless jaw with four implants, twenty (n=20) specimens sectioned into three parts were made. Two groups were formed, each with ten (n=10) specimens. Once conditioned, they were screwed to the master model. Its initial mismatch was analyzed using a stereoscopic magnifier, with a built-in camera and a software. The parts were welded using a different procedure for each group. Those corresponding to Group I were invested in a refractory block based on silyl-phosphate. Those of Group II were mounted on a Clever Spider metal structure. The mismatch was measured, and the results processed statistically. The level of significance was established at p<0.05. Results Group I had an initial mismatch of 97.30 ±13.81μm, and Group II of 98.53±11.24μm. After welding, Group I registered 98.53±17.17μm, 1.23μm higher than the initial one. In Group II, 103.13±17.61μm was observed, 4.60μm above the original. They were analyzed using Student's t test; in both cases the result was p>0.05. When comparing groups I and II, using the t-test and the Mann-Whitney nonparametric verification, non-significant differences were observed, p=0.41 and p=0.38 respectively. Conclusions Under the conditions of this study, it was observed that the two welding methods analyzed were reliable for joining metallic superstructures without affecting their final fit.

Long term bone alterations in aged rats suffering type 1 diabetes.

Increasing duration of type 1 diabetes mellitus alters bone metabolism. Clinical studies and experimental studies in long bones of rats with experimentally induced diabetes have reported a decrease in bone density. Few studies have explored this diabetes related alteration in the maxillae. Given that this finding could indicate the possible development of osteopenia in the maxilla in the long term, the present study sought to analyze alterations in alveolar bone in aged rats, 12, 18, and 24weeks after inducing diabetes, and compare alveolar bone response to that of tibial subchondral bone at the same experimental times. Thirty-six male Wistar rats, 130g body weight, were divided into 2 groups: an experimental group (E) receiving a single i.p. 60mg/kg dose of streptozotocin, and a control group (C). Both the control and experimental groups were divided into 3 sub-sets, according to the time of euthanasia: 12, 18 and 24weeks. The alveolar bone and tibiae were examined histologically and histomorphometrically. The results were analyzed using Student's t-test; a value of p<0.05 was considered statistically significant. RESULTS: Subchondral bone volume and bone activity/remodeling, mainly bone rest, were significantly lower in diabetic animals compared to controls, at both 12 and 18weeks. No differences in alveolar bone parameters were observed between diabetic and control animals at either of the experimental times. Animals surviving at 24weeks showed few trabeculae at rest and severe destruction of dental and periodontal tissues. The results of the present study show that diabetic osteopenia is evident in the tibia at 12 and at 18weeks, whereas its effects on the maxilla can be seen at 24weeks, with substantial destruction of alveolar bone and of the remaining periodontal and dental tissues. All the above observations highlight the need for preventive oral care in diabetic patients, before irreversible damage to dental and periodontal tissues occurs.

Impairment of Bony Crypt Development Associated With Hexavalent Chromium Exposure During Tooth Eruption.

Improperly treated hexavalent chromium-containing industrial wastes contaminate drinking water, potentially affecting children taking breast milk or baby bottles prepared with infant formula. Thus, the aim of the present work was to determine the effect of this toxic on bone activity in the developing alveolus during tooth eruption of suckling Wistar rats intoxicated with potassium dichromate. Experimental animals received a daily dose of 12.5mg/kg body weight of potassium dichromate by gavage for 10 days; controls received an equivalent volume of saline solution. Histologic and histomorphometric studies of the mandible were performed. The data were statistically analyzed using Student's t test; statistical significance was set at a value of p <0.05. Experimental animals exhibited delayed tooth eruption, decreased periodontal width and bone volume, a lower percentage of bone formation surfaces, and higher percentage of quiescent surfaces (p<0.05) compared to controls. The delay in tooth eruption observed after exposure to hexavalent chromium is the result of a lower rate of bone remodeling in the developing alveolus. The obtained results show the importance of controlling toxic substances in drinking water, since their effects may alter the growth and development of subjects who were exposed during early infancy.

Desechos industriales que contienen cromo hexavalente inade- cuadamente tratados contaminan el agua de consumo pudiendo afectar a los niños por vía de la leche materna o de la preparación de mamaderas. Por lo tanto, el objetivo del presente trabajo fue determinar el efecto de este tóxico en la actividad del hueso en el alveolo en desarrollo durante la erupción dentaria de ratas Wistar lactantes expuestas a dicromato de potasio. Los animales experimentales recibieron una dosis diaria de 12,5 mg / kg de peso corporal de dicromato de potasio por alimentación forzada durante 10 días; mientras que los controles, un volumen equivalente de solución salina. Se llevaron a cabo estudios histológicos e histomorfométricos de la mandíbula. Los datos fueron analizados estadísticamente utilizando la prueba t de Student; estableciéndose un valor de p<0,05 como estadísticamente significativo. Los animales expuestos a cromo hexavalente mostraron retraso en la erupción dentaria, menor espacio periodontal y volumen óseo; encontrándose disminuidas las superficies en formación y en reabsorción óseas y aumentadas las superficies en reposo (p <0,05) en comparación con los controles. El retraso en la erupción dentaria observado luego de la exposición a cromo hexavalente es el resultado de una menor remodelación ósea en el alveolo en desarrollo. Los resultados obtenidos muestran la importancia del control de sustancias tóxicas en el agua potable, ya que sus efectos pueden alterar el crecimiento y el desarrollo de los individuos que fueron expuestos durante la infancia temprana.

Impairment of bony crypt development associated with hexavalent chromium exposure during tooth eruption

Improperly treated hexavalent chromium-containing industrial wastes contaminate drinking water, potentially affecting children taking breast milk or baby bottles prepared with infant formula. Thus, the aim of the present work was to determine the effect of this toxic on bone activity in the developing alveolus during tooth eruption of suckling Wistar rats intoxicated with potassium dichromate. Experimental animals received a daily dose of 12.5mg/kg body weight of potassium dichromate by gavage for 10 days; controls received an equivalent volume of saline solution. Histologic and histomorphometric studies of the mandible were performed. The data were statistically analyzed using Student's t test; statistical significance was set at a value of p <0.05. Experimental animals exhibited delayed tooth eruption, decreased periodontal width and bone volume, a lower percentage of bone formation surfaces, and higher percentage of quiescent surfaces (p<0.05) compared to controls. The delay in tooth eruption observed after exposure to hexavalent chromium is the result of a lower rate of bone remodeling in the developing alveolus. The obtained results show the importance of controlling toxic substances in drinking water, since their effects may alter the growth and development of subjects who were exposed during early infancy.

Desechos industriales que contienen cromo hexavalente inade - cua damente tratados contaminan el agua de consumo pudiendo afectar a los ninos por via de la leche materna o de la preparacion de mamaderas. Por lo tanto, el objetivo del presente trabajo fue determinar el efecto de este toxico en la actividad del hueso en el alveolo en desarrollo durante la erupcion dentaria de ratas Wistar lactantes expuestas a dicromato de potasio. Los animales experimentales recibieron una dosis diaria de 12,5 mg / kg de peso corporal de dicromato de potasio por alimentacion forzada durante 10 dias; mientras que los controles, un volumen equivalente de solucion salina. Se llevaron a cabo estudios histologicos e histomorfometricos de la mandibula. Los datos fueron analizados estadisticamente utilizando la prueba t de Student; estableciendose un valor de p<0,05 como esta - disticamente significativo. Los animales expuestos a cromo hexavalente mostraron retraso en la erupcion dentaria, menor espacio periodontal y volumen oseo; encontrandose disminuidas las superficies en formacion y en reabsorcion oseas y aumentadas las superficies en reposo (p <0,05) en comparacion con los controles. El retraso en la erupcion dentaria observado luego de la exposicion a cromo hexavalente es el resultado de una menor remodelacion osea en el alveolo en desarrollo. Los resultados obtenidos muestran la importancia del control de sustancias toxicas en el agua potable, ya que sus efectos pueden alterar el crecimiento y el desarrollo de los individuos que fueron expuestos durante la infancia temprana.

Effect of different doses of hexavalent chromium on mandibular growth and tooth eruption in juvenile Wistar rats.

Not only workers employed at industrial plants are exposed to intoxication with the element they manipulate, the population at large is also at risk of suffering health problems caused by contaminating wastes inadequately treated for their safe disposal. As a result certain toxic substances, such as hexavalent chromium,has reached the general population including children. The present study sought to evaluate the effect of intoxication with hexavalent chromium on body and mandibular growth and tooth eruption in suckling Wistar rats. Potassium dichromate was administered by gavage in a dose of 6.25 or 12.5mg/kg body weight (b.w.) to one of the two groups of 4-day-old Wistar rats during 10 days. Our results showed that the effects of chromium are dose-dependent. Morphometric studies of body growth showed lower body weight in both experimental groups and shorter tail length in animals receiving 12.5mg/kg b.w. dose of chromium, compared with controls. All parameters of mandibular growth were lower in the experimental group receiving 12.5mg/kg b.w. of chromium. Differences in tooth eruption were observed at the level of the first molar in animals receiving 12.5mg/kg and of the second molar in those receiving 6.25mg/kg b.w. of chromium. Chromium was found to affect all the studied parameters.

Alterations of tooth eruption and growth in pups suckling from diabetic dams.

Several studies have confirmed a decrease in the quality and quantity of milk of mothers with diabetes during lactation. However, it remains unclear how maternal diabetes affects the offspring specifically during lactation. The aim of this study was to evaluate body and mandibular growth and tooth eruption in pups suckling from diabetic dams. The study was performed on 13 Wistar rat pups that were born to dams that were subjected to experimental diabetes on the day of parturition. Body weight and body size were recorded regularly throughout the study. The experimental pups and a group of eight age-matched pups suckling from nondiabetic dams were killed at weaning. Both hemimandibles were excised and fixed. Right hemimandibles were radiographed to assess mandibular growth and tooth eruption. The left hemimandibles were processed to obtain buccolingually oriented sections at the level of the first mesial root of the first lower molar. Histologic and histomorphometric studies were performed. Results showed that body weight and body size were significantly lower in experimental animals at weaning compared with their age-matched controls. Smaller mandible size and reduced tooth eruption in experimental animals compared with controls were observed. The length, width, and bone volume of the developing alveolus were reduced in experimental animals compared with controls. The results obtained in this study allow the conclusion that suckling from diabetic dams results in reduced body, mandible size, and tooth eruption of the pups at weaning.