Injerto de matriz ósea en partículas asociado a plasma rico en plaquetas (PRP): estudio experimental / Bone matrix and platelet rich plasma (PRP) grafting: an experimental study

Los injertos o sustitutos óseos se utilizan con el fin de solucionar situaciones de déficit en el hueso, aunque aún existen controversias sobre los mecanismos de osteoinducción que estos rellenos promueven dentro de los tejidos. La combinación con plasma rico en plaquetas (PRP) podría aumentar la capacidad de reparación ósea. Objetivo: estudiar el efecto biológico (biocompatibilidad y osteoinducción) de la matriz ósea de la Universidad Nacional de Córdoba (MO-UNC) y el plasma rico en plaquetas (PRP). Métodos: se utilizaron 30 ratas Wistar anestesiadas con ketamina-xilazina. En 4 sitios del tejido celular subcutáneo de la región dorsal se implantaron tubos de silicona conteniendo los materiales experimentales: MO (partículas de MO-UNC), PRP, MO+PRP (partículas de MO embebidas en PRP), GC (Controles, sin relleno). Se tomaron biopsias de los sitios de implante a los 30 y 60 días poscirugía y se obtuvieron cortes histológicos para analizar la biocompatibilidad y la neoformación ósea alrededor de los materiales implantados. Resultados: si bien en ninguno de los grupos se identificó tejido óseo neoformado, en el grupo MO+PRP a 30 días se constató un aumento del número de cpailares neoformados alrededor de las partículas. A los 60 días, las partículas de MO-UNC mostraron áreas lacunares compatibles con actividad resorsiva. En este estudio, las partículas de MO-UNC se comportaron como injertos biocompatibles, siendo progresivamente resorbidas en el organismo de los animales. Se confirmó un efecto angiogénico del PRP...

Bone substitute in the repair of the post-extraction alveolus.

In recent years there has been increasing interest in the choice of the best material for bone substitutes. Experimental models enable estimation of biological potential, efficacy and safety of a biomaterial before its clinical application. The aim of this study was to evaluate the response of a bone substitute, UNC bone matrix powder (MOeP-UNC), for repairing the post-extraction alveolus in Wistar rats. Rats' first lower molars were extracted. The right alveoli were filled with MOeP-UNC hydrated with physiological saline (Experimental Group, EG), and the left alveoli were used as Control Group (CG). Thirty days after extraction, the animals were killed and the samples processed. Histological sections were made in vestibular-lingual direction at the level of the mesial alveolus of the first inferior molar (Guglielmotti et al. J. Oral Maxillofac. Surg. 1985;43(5):359-364). Repair of the alveoli at 30 days after extraction was evaluated histologically. Repair of the alveolus was optimum in the control group at 30 days, and the EG showed presence of MOeP-UNC particles in close contact with newly formed bone tissue (osseointegration). In the experimental model used, at 30 days post-surgery, the MOeP-UNC particles integrate compatibly with newly formed bone tissue.

Bone substitute in the repair of the post-extraction alveolus

In recent years there has been increasing interest in the choice of the best material for bone substitutes. Experimental models enable estimation of biological potential, efficacy and safety of a biomaterial before its clinical application. The aim of this study was to evaluate the response of a bone substitute, UNC bone matrix powder (MOeP-UNC), for repairing the postextraction alveolus in Wistar rats. Rats' first lower molars were extracted. The right alveoli were filled with MOeP-UNC hydrated with physiological saline (Experimental Group, EG), and the left alveoli were used as Control Group (CG). Thirty days after extraction, the animals were killed and the samples processed. Histological sections were made in vestibular- lingual direction at the level of the mesial alveolus of the first inferior molar (Guglielmotti et al. J. Oral Maxillofac. Surg. 1985;43(5):359-364). Repair of the alveoli at 30 days after extraction was evaluated histologically. Repair of the alveolus was optimum in the control group at 30 days, and the EG showed presence of MOeP-UNC particles in close contact with newly formed bone tissue (osseointegration). In the experimental model used, at 30 days post-surgery, the MOeP-UNC particles integrate compatibly with newly formed bone tissue.

En los ultimos anos se ha incrementado el interes por la eleccion del material mas adecuado como sustituto oseo. Los modelos experimentales permiten estimar el potencial biologico, la eficacia y seguridad de un biomaterial, previo a su aplicacion clinica. El objetivo del presente estudio fue evaluar la respuesta de un sustituto oseo, matriz osea-UNC en polvo (MOeP-UNC), en la reparacion alveolar post-exodoncia en ratas Wistar. Se realizo la exodoncia de los primeros molares inferiores. En los alveolos derechos se coloco MOeP-UNC hidratada con solucion fisiologica (Grupo Experimental, GE). Los alveolos izquierdos, fueron utilizados como Grupo Control (GC). A los 30 dias post-exodoncia los animales fueron sacrificados y las muestras obtenidas se procesaron, se realizaron cortes histologicos en sentido vestibulo-lingual a la altura del alveolo mesial del primer molar inferior (Guglielmotti et al. J Oral Maxillofac Surg. 1985;43(5):359-364). Se realizo la evaluacion histologica de la reparacion de los alveolos a los 30 dias post cirugia. El grupo control presento una optima reparacion alveolar a los 30 dias y en el GE se evidencio la presencia de las particulas de MOeP-UNC en intimo contacto con el tejido oseo neoformado (oseointegracion). En el modelo experimental utilizado, a los 30 dias post-cirugia las particulas MOePUNC se integran de manera compatible con el tejido oseo neoformado.

Effect of low-power radiation (helium/neon) upon submandibulary glands.

OBJECTIVE: The aim of this work was to study the effect of low-power laser radiation on guinea pig salivary glands. BACKGROUND DATA: Low-power laser radiation changes some cellular functions. The effect on salivary glands has not been sufficiently studied. MATERIALS AND METHODS: One hundred and forty-four male guinea pigs (150 +/- 30 g body weight) were used. The animals were divided into two groups: control group (fed animals and those undergoing 2, 4, 8, 10, and 12 h of fasting) and experimental group (irradiated). Both the right and left submandibular glands were later irradiated with helium-neon laser at 7-mW power, with a 0.75-mm spot, under continuous pulse for 2 min in a one-session exposure; a 11.2 J/cm(2) energy density was applied. Then, the irradiated animals were fed, or underwent 2, 4, 8, 10 and 12 h of fasting. Samples of submandibular glands were taken with a punch (5 mm diameter) and were used for optic and transmission electron microscopy studies. RESULTS: The structural observations showed that the irradiation effect was progressive; and showed a trophic stimulant effect at 2 h following irradiation, with vasodilatation, vascular congestion, perivascular infiltrate, and a necrotic picture of glandular parenchyma at longer times. The ultrastructural observations showed alterations of rough endoplasmic reticulum. CONCLUSION: We propose that low-power laser radiation with the doses applied in this study disturbs protein synthesis and secretion of guinea pig submandibulary glands.