Comparison of root resorption between self-ligating and conventional preadjusted brackets using cone beam computed tomography

Objective:To compare the magnitude of external apical root resorption (EARR) of incisors in patients undergoing the initial phase of orthodontic treatment with two sets of brackets.Materials and Methods:According to the results of the power analysis for sample size calculation, 19 Angle Class I patients (anterior crowding: 3 to 5 mm; mean age: 20.6 years) were included in the study and randomly divided into two groups: group I (n  =  11, self-ligating brackets) and group II (n  =  8, conventional preadjusted brackets). The degree of EARR was detected in 152 upper and lower incisors by using cone-beam computed tomography (CBCT) scans and a three-dimensional program (Dolphin 11.5, Dolphin Imaging & Management Solutions, Chatsworth, Calif) with 25% level of sensitivity. The CBCT scans were obtained before (T1) and 6 months after initiation of treatment (T2). Differences between and within groups were analyzed by nonpaired and paired t-test, respectively, with 5% significance level.Results:Significant differences were found for both groups between T1 and T2. However, no differences in the degree of EARR were detected between the groups studied.Conclusions:Although EARR has occurred in all teeth evaluated, the bracket design (self-ligating or conventional) did not demonstrate any influence on the results observed.     

Effect of topical application of fluoride gel NaF 2% on enzymatic and non-enzymatic antioxidant parameters of saliva

ObjectiveThe aim of the study was to evaluate the effect of topical fluoride gel NaF 2% application on antioxidant parameters of whole saliva from children.DesignThe saliva mechanically stimulated with parafilm was collected from 25 children (6–12 years) attending the Clinic of Paediatric Dentistry of Universidade Cruzeiro do Sul, São Paulo, Brazil, before (control group) and immediately after application of neutral fluoride gel NaF 2% (fluoride-gel group), according to the Standards for Research Using Human Subjects, Resolution 196/96 of the USA National Health Council of 10/10/1996. Afterwards, pre-post ferric-reducing antioxidant power (FRAP), trolox-equivalent antioxidant capacity (TEAC), uric acid, reduced/oxidised glutathione content (GSH/GSSG) and total peroxidase activity (TPO) were evaluated in whole saliva of both groups.ResultsAll non-enzymatic antioxidant parameters were augmented by fluoride-gel NaF 2% application, whereas a notable reduction (31%) of peroxidase activity was concomitantly observed in the children's saliva (p ≤ 0.05). Nevertheless, the reducing power of saliva was kept unaltered under these circumstances (p ≤ 0.05).ConclusionsDespite the reduced activity of peroxidase (an important antimicrobial and antioxidant enzyme), the topical fluoride gel NaF 2% favourably stimulated the release of non-enzymatic antioxidant components of saliva, sustaining the reducing power of saliva and the natural defences of the oral cavity.     

Effect of hypoxanthine, antioxidants and allopurinol on cholinesterase activities in rats

In the present study, we investigate the in vitro effect of hypoxanthine on acetylcholinesterase and butyrylcholinesterase activities in the hippocampus, striatum, cerebral cortex and serum of 15-, 30- and 60-day-old rats. Furthermore, we also evaluated the influence of antioxidants, namely α-tocopherol (trolox) and ascorbic acid, and allopurinol to investigate the possible participation of free radicals and uric acid in the effects elicited by hypoxanthine on these parameters. Acetylcholinesterase and butyrylcholinesterase activities were determined according to Ellman et al. (Biochem Pharmacol 7:88–95, 1961), with some modifications. Hypoxanthine (10.0 μM), when added to the incubation medium, enhanced acetylcholinesterase activity in the hippocampus and striatum of 15- and 30-day-old rats and reduced butyrylcholinesterase activity in the serum of 60-day-old rats. The administration of allopurinol and/or antioxidants partially prevented the alterations caused by hypoxanthine in acetylcholinesterase and butyrylcholinesterase activities in the cerebrum and serum of rats. Data indicate that hypoxanthine alters cholinesterase activities, probably through free radicals and uric acid production since the alterations were prevented by the administration of allopurinol and antioxidants. It is presumed that the cholinesterase system may be associated, at least in part, with the neuronal dysfunction observed in patients affected by Lesch–Nyhan disease. In addition, although extrapolation of findings from animal experiments to humans is difficult, it is conceivable that these vitamins and allopurinol might serve as an adjuvant therapy to avoid progression of brain damage in patients affected by this disease.     

Effects of unilateral stereotactic posterior striatotomy on harmaline‐induced tremor in rats

Although long known and the most prevalent movement disorder, pathophysiology of essential tremor (ET) remains controversial. The most accepted hypothesis is that it is caused by a dysfunction of the olivocerebellar system. Vilela Filho et al. [2001; Stereotact Funct Neurosurg 77:149–150], however, reported a patient with unilateral hand ET that was completely relieved after a stroke restricted to the contralateral posterior putamen and suggested that ET could be the clinical manifestation of posterior putamen hyperactivity. The present study was designed to evaluate this hypothesis in the most often used model of ET, harmaline‐induced tremor in rats. Fifty‐four male Wistar rats were randomly distributed into three groups: experimental (EG), surgical control (SCG), and pharmacological control (PCG) groups. EG animals underwent stereotactic unilateral posterior striatotomy. SCG rats underwent sham lesion at the same target. PCG served exclusively as controls for harmaline effects. All animals received, postoperatively, intraperitoneal harmaline, and the induced tremor was video‐recorded for later evaluation by a blind observer. Thirteen animals were excluded from the study. Limb tremor was reduced ipsilaterally to the operation in 20 of 21 rats of EG and in two of nine of SCG, being asymmetric in one of 10 of PCG rats. Comparisons between EG × SCG and EG × PCG were statistically significant, but not between SCG × PCG. Limb tremor reduction was greater in anterior than in posterior paws. Lateral lesions yielded better results than medial lesions. These results suggest that the posterior striatum is involved with harmaline‐induced tremor in rats and support the hypothesis presented. © 2013 Wiley Periodicals, Inc.     

Korotkoff sounds: development of the sphygmomanometry research at the Nursing School of the USP

This article pays homage to Sergei Nicolai Korotkoff, for the centenary of the auscultatory method discovery. It refers to his discover of blood pressure auscultatory method in Russia, in 1905; presents the evidence that resulted in the development of sphygmomanometry studies in Brasil; describes the important contribution of the Nursing School of the University of S?o Paulo to the development of blood pressure measurement research; and analyses the results of the research field of "Cuff width influence in blood pressure measurement", created at the Nursing School of The University of S?o Paulo, in 1974. The scientific results of doctoral studies are presented, identifying the research groups that are contributing to defying knowledge in this area. The article demonstrates the consolidation of the results related to the initial doctoral program studies developed in the area. Confirmation of hypothesis in longitudinal studies is emphasized.