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Purpose: To compare the effectiveness of an agent that promotes deposition of amorphous calcium phosphate (Quell Desensitizer) to a commonly used product, sodium fluoride solution (Nupro Neutral), in the reduction of root sensitivity after periodontal therapy, in a prospective, convenient sample, double-blind clinical trial., Methods: Thirty patients were enrolled and treated, resulting in 40 teeth treated with the test product and 40 teeth treated with the control product. The clinical parameters tested at baseline and in the follow-up visits (1, 2, and 4 weeks after treatment) were the following: plaque index, gingival index, gingival recession, and response to mechanical and cold stimulation with airblast and ice. Patients were also asked to report the grade of pain response on a Visual Analogue Scale (VAS) on the same schedule as the clinical parameters., Results: Plaque index and gingival index were not significantly different between test and control groups throughout the study. Most recession was observed on midbuccal surfaces. Buccal surfaces evoked higher pain response compared to lingual surfaces. It was concluded that both control and test treatments reduced root sensitivity response reported with mechanical or cold stimulation. No statistically significant differences were observed when the data of both groups were compared by a Student's t-test at the 0.05 level of significance.

Purpose: To examine, in vitro, the caries-like lesion formation in enamel adjacent to fluoride-releasing orthodontic bonding agents using polarized light microscopic techniques., Methods: 40 human extracted permanent third molars with sound enamel smooth surfaces were divided into two treatment groups: Light Bond group, a fluoride-releasing filled resin orthodontic bonding agent (n=20); and Pro Seal group, an orthodontic bonding agent with glass-ionomer (n=20). Prior to bonding agent placement on the buccal surfaces, acid-resistant varnish was applied to the molar teeth leaving a 2 mm (occlusal-cervical direction) by 5 mm (mesial-distal direction) exposed sound enamel window on the buccal surfaces of each molar tooth. The exposed window had the assigned orthodontic bonding agent applied, according to the manufacturer's instructions. With each specimen, a 1 mm (occlusal-cervical direction) by 5 mm (mesiodistal direction) sound enamel window was exposed by selectively removing the acid-resistant varnish on the opposing lingual or palatal surface with each molar tooth, and serving as a matched internal control with each molar. The molar teeth were then sectioned into buccal and lingual/palatal tooth halves. Acid-resistant varnish was applied to the cut surfaces. Each group underwent synthetic saliva rinsing for 2 weeks prior to in vitro caries formation using a modified ten Cate solution over a 2-week lesion initiation period. Longitudinal sections (three per treatment and control groups) were taken for polarized light study. The remaining tooth portions were exposed to synthetic saliva rinsing for 1 week and then exposed to the in vitro caries solution for an additional 1-week period to allow for lesion progression within the exposed enamel windows (progression 1 period). Longitudinal sections (three per treatment and control groups) were taken at the end of lesion progression 1 for polarized light study. After lesion progression 1, the remaining tooth portions were exposed to synthetic saliva rinsing for 1 week and then exposed to the in vitro caries solution for 1 week to allow for additional lesion progression within the exposed enamel windows (progression 2 period). Longitudinal sections (three per treatment and control groups) were taken at the end of lesion progression 2 for polarized light study. All longitudinal sections from the treatment and control groups at all three time periods (lesion initiation, progression 1 and progression 2) were imbibed with water and examined with polarized light microscopy to determine lesion depths and evaluate the enamel-resin interface. Mean (SD) lesion depths were determined and compared (ANOVA, t-test)., Results: Following lesion initiation, lesion progression 1 and lesion progression 2 periods, both treatment groups exhibited significant reductions in mean lesion depth when compared with the matched no treatment control group (P< 0.05). The Pro Seal group exhibited statistically significant reductions in mean lesion depths when compared with those for the Light Bond group at lesion initiation, lesion progression 1 and lesion progression 2 periods (P< 0.05, ANOVA, t-test). Both orthodontic bonding agents showed intact and intimate enamel-bonding agent interfaces with no lesion formation within the underlying bonded enamel. Caries-like lesions were only present in the exposed enamel windows adjacent to the orthodontic bonding agents.

Background: It is unclear whether the protective benefits of regular physical activity on mortality extend to patients with end-stage renal disease (ESRD). We tested this hypothesis in a national cohort of new patients with ESRD in the United States., Methods: Data for a subset of patients (n = 2,507; 62%) from the Dialysis Morbidity and Mortality Wave 2 study were used to explore the associations of exercise and limitations in physical activity with mortality., Results: Overall, 56% of patients exercised less than once a week, whereas the remainder reported more frequent physical activity; 2 to 3 times/wk in 18%, 4 to 5 times/wk in 6%, and daily exercise in 20%. Severe limitations in vigorous and moderate physical activities were reported by 75% and 42%, respectively. Mortality risks were greatest for those with severe limitations in either moderate (relative risk [RR], 1.72; 95% confidence interval [CI], 1.44 to 2.05) or vigorous physical activities (RR, 1.51; 95% CI, 1.20 to 1.90) compared with those reporting minimal or no limitations. Conversely, mortality risks were lower for patients who exercised 2 to 3 (RR, 0.74; 95% CI, 0.58 to 0.95) or 4 to 5 times/wk (RR, 0.70; 95% CI, 0.47 to 1.07), whereas no advantage was associated with daily exercise (RR, 1.06; 95% CI, 0.86 to 1.30)., Conclusion: Although limitations in physical activity are common among new patients with ESRD in the United States and correlate highly with increased mortality risk, this study shows an association of frequent exercise of up to 4 to 5 times/wk with improved survival. The surprising lack of association of daily exercise with increased survival deserves additional study.