Alveolar bone loss induced by chronic ethanol consumption from adolescence to adulthood in Wistar rats.

Though there are literature indicating the bone loss due to alcohol consumption, studies on the association between ethanol consumption and periodontal breakdown in animals are either scarce or have provided conflicting results. Here, we investigated the effects of chronic alcohol exposure from adolescence to adulthood on the alveolar bone in rats. Wistar rats were exposed to ethanol (6.5 g/kg/day) in a solution of 22.5% (w/v) or distilled water (control) by gavage from 35 days of age (adolescent) until 90 days (adulthood). Evaluation of the bone loss was performed using scanning electronic microscopy, in which the distances between the cement-enamel junction and the alveolar bone crest from the palatal side of the first molar mandibular were measured. The measurements obtained were tabulated and analyzed using Student’s t-test. Alcohol-treated group revealed greater bone loss in comparison to the control group. These findings indicate that heavy chronic alcohol exposure from adolescent to adulthood can induce alveolar bone loss in rats associated to absence of periodontitis.

Particulate bone matrix usage for alveolar bone conservation. A histomorphometric study / Particulate bone matrix usage for alveolar bone conservation. A histomorphometric study.

UNLABELLED: Different filling materials have been used in an attempt to repair bone loss situations. OBJECTIVE: The present study aimed to examine the effect of a bone matrix in post - extraction remodelling of the alveolar bone, and to perform a histomorphometric analysis of the residual alveolar ridges in Wistar rats. MATERIAL AND METHODS: Both rat first lower molars were extracted and the right alveoli were filled with particles of a bone matrix with mineral components (MO - UNC) (experimental group, EG). The left alveoli were used as a control group (CG). The animals were sacrificed at 0 hr., 15, 30 and 60 days after extraction, and the samples were processed. Histological sections were made at the level of the mesial alveolus of the first lower molar. Repair of the alveoli was histologically evaluated and a histomorphometric study of total alveolar volume (TAV), height of the buccal plate (Bh), height of the lingual plate (Lh) and percentage of osseointegration (OI) of the particles was performed to compare the residual ridges of CG with those of the EG. Statistical analysis of the data was performed. RESULTS: In the cases of the experimental group, newly - formed bone tissue was identified around the MO - UNC particles (osseointegration). Histomorphometric data indicate that, at 60 days post - extraction, TAV was significantly greater for EG when compared with CG (p <0.05) and the percentage of osseointegration of the particles increased as a function of time (57.6

, for EG at 15, 30 y 60 days respectively). CONCLUSIONS: The bone matrix (MO - UNC) evaluated in this study is an osteoconductive material that prevents the collapse of post - extraction alveolar bone.

The lacuno-canalicular system (LCS) and osteocyte network of alveolar bone by confocal laser scanning microscopy (CLSM) / Características del sistema lacuno-canalicular (lcs) y la red osteocitaria del hueso alveolar observadas por microscopía láser de barrido confocal (clsm)

El sistema lacuno-canalicularosteocitario (OLCS) comprende una amplia red de intercomunicación entre las lagunas y loscanalículos que contienen a los osteocitos y sus procesos citoplasmáticos dentro de la matriz ósea mineralizada, de lo que depende su vitalidad y funcionamiento. Hasta el momento no se han estudiado las características tridimensionales delOLCS en el hueso alveolar por lo que el objetivo del presente trabajo fue de eterminarla por microscopía de barrido co nfocal. Muestras de hueso alveolar de ratas Wistar machos, luego fijadas en formol buffer fueron teñidas con fucsina básicapar a visualizar el sistema lacuno-canalicular y a muestrasdescalcificadas del mismo hueso mediante una falotoxinafluorescente se les marcó la actina para visualizar la redosteocitaria. Las muestras se observaron a nivel de la raízmesial del primer molar superior en sentido buco-palatinocon un microscopio láser de barrido confocal. Los resultadosmostraron que en la zona aledaña a la cortical periodontal dela tabla ósea vestibular las lagunas osteocitarias presentanforma ovalada y tamaño relativamente uniforme, alinéandoseparalelas entre sí y con su eje mayor paralelo a la superficieósea periodontal en tanto que los osteocitos, de forma ovalada,presentan su eje mayor orientado perpendicularmente a dicha superficie y con los procesos citoplasmáticos irradiándose en todos los sentidos del espacio. En la zona aledaña ala cortical periodontal de la tabla ósea palatina las lagunas osteocitarias se presentan de forma redondeada y tienen distintos tamaños, sin seguir un patrón de orientación específico, y los cuerpos osteocitarios presentan su eje mayor paralelo a una dirección más recta que en la tabla vestibular.

Changes in the alveolar vestibular bone compacta following extraction of an incisor tooth in rats, scanning electron microscopy study

Com o objetivo de verificar as modificaçöes que ocorrem na superfície óssea da face vestibular do alvéolo de ratos após exodontia de incisivos, realizou-se estudo através da microscopia eletrônica de varredura. Trinta ratos Albinus Wistar machos adultos foram divididos em 6 grupos experimentais de 5 animais cada, além do grupo controle também 5 animais, porém näo operados. Cada animal sofreu extraçäo do seu incisivo central superior direito; os grupos foram sacrificados no 5§, 10§, 15§, 20§ e 40§ dia pós-operatório. As peças foram fixadas em soluçäo de Karnovsky modificada, durante 12 horas, e tratadas depois com a soluçäo de hipoclorito de sódio a 5%, conforme a técnica descrita por TAKIGUCHI (1977) e LESTER et al. (1981). O microscópio eletrônico utilizado foi o da Jeal JSM-P15. Baseados em nossos resultados podemos concluir que: 1. A superfície externa do osso compacto da face vestibular de alvéolos incisivos de ratos normais apresenta um revestimento formado por um arranjo de espessos feixes de fibras colágenas calcificadas e numerosos forames vasculares, que medem de 3,5 a 80 micrômetros de diâmetro. 2. Nos animais sacrificados 5 dias após a extraçäo näo houve alteraçöes dígnas de nota em comparaçäo com os do grupo controle. A característica de superfície lisa e uniforme, revestida por espessos feixes de fibras colágenas foi marcante; 3. Aos 10 dias após a cirurgia, houve reorganizaçäo tecidual da face vestibular do alvéolo, com formaçäo de grande quantidade de canais vasculares e áreas de reabsorçäo em diversas regiöes. Os padröes de distribuiçäo do trabeculado ósseo superficial modificou-se em grande parte nas margens do alvéolo e da crista alveolar, sendo agora numerosos os forames vasculares com diâmetros entre 0,2 e 0,9 micrômetros e lacunas de osteócitos. 4. Nos animais com sobrevida de 15 dias as modificaçöes da superfície óssea säo intensas, caracterizadas por pequenos forames vasculares, lacunas de osteócitos, áreas de reabsorçäo...