Evaluation of some biological aspects of the presence of abrasive silica and thickening silica in basic formulations of dentifrices / Evaluación de algunos aspectos biológicos de la presencia de sílice abrasivo y sílice espesante en formulaciones básicas de dentífricos

The aim of this study was to evaluate some biological characteristics and toxicity of basic formulations of dentifrices containing such substances, and to compare them with two existing products in market which also contains silic in their formulations. In this way, it was evaluated some biological parameters: weight of the animals, oral toxicity, hematological parameters, urinary analysis, and histological evaluation. The thrombocytes were also statistically at normal levels. The glutamate-pyruvate transaminase (TGP) showed normal aspect in 5 of the tested groups, as in control. Meanwhile, the oxalacetic transaminase (AST) in one group had a small increase in the control group. Regarding urine, in exception the rats of one group, the rats of the 4 other experimental groups showed leukocytosis urinary statistically higher than the control group. The histological evaluation of the animals showed that specimens from liver, stomach, kidney and submandibular gland presented normal aspects for these organs, without significant characteristics related to inflammatory infiltrates in any of the 6 samples tested in their respective groups.

El objetivo del estudio fue evaluar algunas características biológicas y de toxicidad provenientes de las formulaciones básicas de dentífricos que contienen sílice en su composición y compararlos con dos dentífricos disponibles comercialmente que también presentan sílice. El análisis hematológico no mostró diferencias entre los grupos evaluados. Los niveles de trombocitos presentados por los grupos fueron también normales. La transaminasa gluámico pirúbica se mostró un aspecto normal en 5 de los grupos estudiados, así como en el grupo control. La transaminasa glutámico oxaloacética en uno de los grupos tuvo un pequeño incremento. En relación a la orina, 4 grupos presentaron leucocitosis urinaria significativamente mayor que el grupo de control. La evaluación histológica del hígado, estómago, riñones y glándulas submandibulares se presentó con aspecto normal, sin presencia de infiltrado inflamatorio.

Metronidazole-containing gel for the treatment of periodontitis: an in vivo evaluation

The aim of this investigation was to monitor metronidazole concentrations in the gingival crevicular fluid (GCF) collected from periodontal pockets of dogs after treatment with an experimental 15 percent metronidazole gel. Five dogs had periodontitis induced by cotton ligatures placed subgingivally and maintained for a 30-day period. After the induction period, only pockets with 4 mm or deeper received the gel. Each pocket was filled up to the gingival margin by means of a syringe with a blunt-end needle. GCF was collected in paper strips and quantified in an electronic device before and after 15 minutes, 1 h, 6 h, 24 h and 48 h of gel administration. The GCF samples were assayed for metronidazole content by means of a high performance liquid chromatography method. Concentrations of metronidazole in the GCF of the 5 dogs (mean ± SD, in µg/mL) were 0 ± 0 before gel application and 47,185.75 ± 24,874.35 after 15 minutes, 26,457.34 ± 25,516.91 after 1 h, 24.18 ± 23.11 after 6 h, 3.78 ± 3.45 after 24 h and 3.34 ± 5.54 after 48 h. A single administration of the 15 percent metronidazole gel released the drug in the GCF of dogs in levels several-fold higher than the minimum inhibitory concentration for some periodontopathogens grown in subgingival biofilms for up to one hour, but metronidazole could be detected in the GCF at least 48 hours after the gel application.