The aim of this study was to assess the radioprotective effects of sodium selenite on parotid glands in rats by ultrastructural analysis of acinar cells. Four experimental groups were assessed; ...control, irradiated, selenium, and selenium/irradiated. The sodium selenite dose was 0.5 mg/kg, administered intraperitoneally 24 h before irradiation in the head and neck region with a single 15-Gy dose of gamma radiation. At 4, 8, 12, 48 and 72 h after irradiation, all animals were sacrificed and the parotid glands were removed. Radiation caused cellular changes from 4 h, and the organelles that presented the greatest alterations were the mitochondria and the secretion glands; nuclear alterations were also observed. Sodium selenite was found to have a radioprotective action, as the selenium/irradiated group presented with less damage when compared to the irradiated group. However, sodium selenite caused cellular alterations that were evident after 8 h, but with less damage when compared to those caused by radiation, which demonstrates a favorable risk-benefit for its use as a radioprotector. Thus, this research shows that sodium selenite has an effective radioprotective action in the parotid gland, which may contribute to the reduction of the adverse effects brought by the radiotherapy. (J Oral Sci 52, 369-375, 2010)
The electrooxidative behavior of citalopram (CTL) in aqueous media was studied by cyclic voltammetry (CV) and square-wave voltammetry (SWV) at a glassy-carbon electrode. The electrochemical behaviour ...of CTL involves two electrons and two protons in the irreversible and diffusion controlled oxidation of the tertiary amine group. The maximum analytical signal was obtained in a phosphate buffer (pH = 8.2). For analytical purposes, an SWV method and a flow-injection analysis (FIA) system with amperometric detection were developed. The optimised SWV method showed a linear range between 1.10 × 10
−5
-1.20 × 10
−4
mol L
−1
, with a limit of detection (LOD) of 9.5 × 10
−6
mol L
−1
. Using the FIA method, a linear range between 2.00 × 10
−6
-9.00 × 10
−5
mol L
−1
and an LOD of 1.9 × 10
−6
mol L
−1
were obtained. The validation of both methods revealed good performance characteristics confirming applicability for the quantification of CTL in several pharmaceutical products.
Background: The present study investigated the possible influence of nicotine on the bone loss rate in the furcation region due to ligature‐induced periodontitis in rats.
Methods: Twenty adult male ...Wistar rats were included. After anesthesia, the tooth was randomly assigned to receive the cotton ligature in the sulcular area, while the contralateral tooth was left unligated. The animals were randomly assigned to one of the following treatments, including daily intraperitoneal injections: group A, 2 μl/g body weight of saline solution; group B, 2 μl/g body weight of a nicotine solution with 0.13 μl of nicotine/ml of saline solution; group C, 2 μl/g body weight of a nicotine solution with 0.19 μl of nicotine/ml of saline solution; and group D, 2 μl/g body weight of a nicotine solution with 0.26 μl of nicotine/ml of saline solution. Thirty days later, the animals were sacrificed and the specimens routinely processed for serial decalcified sections.
Results: Intergroup analysis revealed greater bone loss in the ligated teeth of group B (1.01 ± 0.61 mm2), group C (1.14 ± 0.72 mm2), and group D (1.36 ± 0.60 mm2) when compared with group A (0.64 ± 0.62 mm2) (P <0.01). However, no statistically significant differences in bone loss were found among groups B, C, and D. In addition, no bone loss was observed for unligated teeth (P >0.01).
Conclusions: Within the limits of the present study, nicotine enhanced the effects of the local components of periodontal disease in a non‐dose‐dependent way; nevertheless, the administration of nicotine did not produce periodontal bone loss by itself. J Periodontol 2000;71:1460‐1464.
The present study investigated the effect of nicotine administration on periodontal breakdown resulting from ligature‐induced periodontitis in rats. Twenty adult male Wistar rats were used. After ...anesthesia, a mandibular first molar was randomly assigned to receive a cotton ligature in the sulcular area while the contralateral tooth was left unligated. The animals were randomly assigned to one of the following treatments, of daily intraperitoneal injections: A – saline solution, B – 0.37 mg of nicotine/kg, C – 0.57 mg of nicotine/kg and D – 0.73 mg of nicotine/kg. Thirty days later, the animals were sacrificed and the specimens routinely processed for serial decalcified sections. Statistical analysis (ANOVA) revealed greater bone loss (p<0.05) in the ligated teeth of animals which received nicotine (groups B/C/D) than in the ligated teeth of animals which received saline solution (group A). In addition, a dose‐dependent response was observed among the nicotine groups. A negative effect of nicotine was observed in the unligated teeth of the experimental groups (p<0.05). Therefore, daily administration of nicotine enhanced, in a dose‐dependent manner, the effects of local factors in producing periodontal breakdown. Furthermore, the nicotine seemed to have a direct deleterious effect on the periodontal tissues.
Periodontitis and osteoporosis, diseases that affect millions of people in world, present bone loss as common hallmark. Prevalence of both osteoporosis and tooth loss increase with advancing age in ...both women and men. Systemic bone loss has been proposed as a risk factor for periodontal disease with increasing evidences that osteoporosis, and the underlying loss of bone mass characteristic of this disease, is associated with periodontal disease and tooth loss. Periodontitis has long been defined as an infection-mediated destruction of the alveolar bone and soft tissue attachment to the tooth, responsible for most tooth loss in adult populations. Current evidences including several prospective studies support an association of osteoporosis with the onset and progression of periodontal disease in humans. Systemic loss of bone density in osteoporosis, including that of the jaw, may provide a host system that is increasingly susceptible to infectious destruction of periodontal tissue. Studies have provided evidence that hormones, heredity, and other host factors influence periodontal disease’s incidence and severity. This paper reviews the role of estrogen deficiency and osteoporosis in oral bone healthy and the current evidences on the association between periodontal disease and osteoporosis.
The aim of this work was to describe the development of the periodontal ligament and the distribution of collagen fibers in lower rats incisors, through picrosirius polarization method. It was ...observed that transgingival eruption takes place between the days 10-13 with thin collagen fibrils from periodontal ligament more organized in the tooth related region, showing greenish birefringence. Functional occlusion occurred starting from the 16th day of life together with the maturation of ligament fibers that showed either red or yellow intense birefringence. Our findings indicate that the degrees of molecular organization and alignment of collagen fibers in the alveolar bone and tooth-related areas of the ligament are higher than those in the intermediate area and tend to increase near a more incisal region. It is also suggested that the collagen fibers in the intermediate periodontal ligament area remain immature along the long axis of the incisor even after the functional occlusion period is reached.
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