Preliminary study on the biocompatibility and osteoconductive properties of a new bovine bone graft / Estudio preliminar sobre las propiedades de biocompatibilidad y osteoconductividad de un nuevo injerto de hueso bovino

To prevent post-extraction resorption and preserve the integrity of the alveolar ridges, the placement of bone grafts at the time of extraction is recommended. Bovine bone grafts are biocompatibile and osteoconductive, allowing new bone apposition by osteoprogenitor cells. Although there are trademarks recognized internationally regarding bovine bone grafts, they are expensive and even difficult to acquire. Therefore, domestic industry development of high quality biomaterials will reduce the public health high costs in the dental field. Here, we evaluated and compared the effects of an Argentinean manufactured bovine bone graft (Synergy Bone Matrix) with a bovine bone graft recognized for its osteoconductive effects (Bio-Oss), on bone healing in an experimental model in rats. We created critical sized bone defects in rat tibiae and filled them with either one of the bovine bone grafts or control. Clinical responses, X-ray findings, bone mineral density, and histological parameters were evaluated. No abscess, encapsulation, suppuration or inflammation of lymphatic nodes were observed. Radiographically, all implants were amalgamated to the surrounding bony margins, suggesting proper healing. On the other hand, control tibiae exhibited no signs of recovery and remained either unfilled or showed fibrous tissue formation. No statistical differences were observed in BMC and BMD between tibiae filled with Synergy Bone Matrix or Bio-Oss. Histological analysis revealed particles of both bone grafts surrounded by laminar bone tissue indicating osteoconductivity, without any inflammatory sign. This preliminary study suggests that Synergy Bone Matrix, as well as Bio-Oss, present similar properties of biocompatibility and osteoconductivity. (AU)

Para prevenir la resorción post-exodoncia y preservar la integridad de los rebordes alveolares, se recomienda la colocación de injertos óseos en el momento de la extracción. Los injertos de hueso bovino son biocompatibles y osteoconductivos, permitiendo nueva aposición ósea por células osteoprogenitoras. Existen marcas internacionales de injertos de hueso bovino, pero resultan caros e incluso difíciles de adquirir. Por ello, la elaboración de biomateriales de alta calidad, nacionales, reduciría los altos costos de salud pública en odontología. En este estudio, se evaluaron y compararon los efectos de un injerto de hueso bovino fabricado en Argentina (Synergy Bone Matrix) versus un injerto de hueso bovino reconocido por sus efectos osteoconductivos (Bio-Oss), en el proceso de cicatrización ósea en un modelo experimental en ratas. Para ello, creamos un defecto óseo crítico en tibia de rata el cual se rellenó con uno de los injertos de hueso bovino o control. Se evaluó: respuesta clínica y radiográfica, densidad mineral ósea e histología. No se observaron abscesos, encapsulación, supuración o inflamación de los ganglios linfáticos. Radiográficamente, todos los implantes se integraron a los márgenes óseos circundantes, sugiriendo una cicatrización adecuada. Por el contrario, las tibias control no mostraron signos de recuperación con formación de tejido fibroso. No se observaron diferencias estadísticas en las BMC y BMD entre las tibias Synergy Bone Matrix o Bio-Oss. La histología reveló partículas de ambos injertos óseos rodeadas por tejido óseo laminar indicando osteoconductividad sin signos inflamatorios. Este estudio preliminar sugiere que Synergy Bone Matrix presenta propiedades similares de biocompatibilidad y osteoconductividad que Bio-Oss. (AU)

Atherogenic cholesterol-rich diet and periodontal disease.

OBJECTIVE: This study investigated the effect of an atherogenic cholesterol-rich diet (AT) on the alveolar bone loss in rats with ligature-induced experimental periodontitis (EP). METHODS: Female Wistar adult rats were assigned either a control (Co) or an AT diet fed for 9 weeks. The AT diet was high in saturated fat, cholesterol and energy. At week 2, animals were subjected to a unilateral ligature (L) around the left first molar (Co+L and AT+L). The contra lateral first right molar (not ligated) of both groups (Co and AT) were used as untreated controls. At week 9, blood was drawn, rats were euthanized, hemi-mandibles removed and stained digital photographs (buccal and lingual surfaces) and radiographs were obtained for quantification of alveolar bone loss (ABL). The ABL was determined by distance and area methods (mm(2)) and X-rays were used for periodontal bone support (PBS), (%). RESULTS: Rats in the AT group exhibited a 17% increase in energy intake, gained significant body weight and showed the highest serum total-cholesterol (T-C) and non-high density lipoprotein-cholesterol (HDL-C) levels (p<0.001). The amount of lost periodontal bone was the greatest in AT+L rats. AT feedings significantly increased the buccal area and distance of bone loss when compared with the unligated-teeth (p<0.001). The rats in the AT+L group also achieved the lowest percentage of PBS (p<0.001). The AT and Co+L rats showed similar PBS. This method more clearly elucidated the effect of the cholesterol-rich AT, with and without the influence of molar ligature, compared to the morphometric analysis. CONCLUSION: The alveolar bone loss of EP was magnified by ingestion of an atherogenic diet high in saturated fatty acids and cholesterol.