Influence of concentration, time and method of application of citric acid and sodium citrate in root conditioning

Objective

The aim of this study was to establish the parameters of concentration, time and mode of application of citric acid and sodium citrate in relation to root conditioning.

Material and Methods

A total of 495 samples were obtained and equally distributed among 11 groups (5 for testing different concentrations of citric acid, 5 for testing different concentrations of sodium citrate and 1 control group). After laboratorial processing, the samples were analyzed under scanning electron microscopy. A previously calibrated and blind examiner evaluated micrographs of the samples. Non-parametric statistical analysis was performed to analyze the data obtained.

Results

Brushing 25% citric acid for 3 min, promoted greater exposure of collagen fibers in comparison with the brushing of 1% citric acid for 1 minute and its topical application at 1% for 3 min. Sodium citrate exposed collagen fibers in a few number of samples.

Conclusion

Despite the lack of statistical significance, better results for collagen exposure were obtained with brushing application of 25% citric acid for 3 min than with other application parameter. Sodium citrate produced a few number of samples with collagen exposure, so it is not indicated for root conditioning.     

Water sorption of CH3- and CF3-Bis-GMA based resins with additives

Objectives

To evaluate the effect of additives on the water sorption characteristics of Bis-GMA based copolymers and composites containing TEGDMA, CH₃Bis-GMA or CF₃Bis-GMA.

Material and methods

Fifteen experimental copolymers and corresponding composites were prepared combining Bis-GMA and TEGDMA, CH₃Bis-GMA or CF₃Bis-GMA, with aldehyde or diketone (24 and 32 mol%) totaling 30 groups. For composites, barium aluminosilicate glass and pyrogenic silica was added to comonomer mixtures. Photopolymerization was effected by 0.2 wt% each of camphorquinone and N,N-dimethyl-p-toluidine. Specimen densities in dry and water saturated conditions were obtained by Archimedes'' method. Water sorption and desorption were evaluated in a desorption-sorption-desorption cycle. Water uptake (%WU), water desorption (%WD), equilibrium solubility (ES; µg/mm³), swelling (f) and volume increase (%V) were calculated using appropriate equations.

Results

All resins with additives had increased %WU and ES. TEGDMA-containing systems presented higher %WU, %WD, ES, f and %V values, followed by resins based on CH₃Bis-GMA and CF₃Bis-GMA.

Conclusions

Aldehyde and diketone led to increases in the water sorption characteristics of experimental resins.     

Diagnosis and prognostic value of restrictive ventilatory disorders in the elderly: a systematic review of the literature

Although less extensively studied compared to pulmonary obstructive diseases, restrictive lung disease (RLD) is highly prevalent and frequently disabling in the adult and, more, the elderly population. The underlying conditions may be either primarily pulmonary diseases, such as idiopathic pulmonary fibrosis, or non respiratory conditions secondarily affecting the lung, e. g. congestive heart failure, or else conditions affecting the lung expansion, e. g. obesity or rib cage deformity. The diagnosis is frequently based on the measurement of surrogate indexes such as the forced vital capacity (FVC) used as a proxy for total lung capacity (TLC). As a consequence, diagnosis of RLD is often characterized by poor specificity. In the elderly, worsening in the quality of life and poor prognosis are variably, but significantly, associated to RLD, being the underlying condition an important source of variability. Several causes of RLD are preventable and treatable conditions. A prompt identification of these conditions may allow to slow the decline of respiratory reserve and, thus, to preserve both personal independence and resistance to acute respiratory infections. This review gives an update on the latest evidence available on the prevalence and the prognosis of RLD in the elderly. Studies were identified through systematic searches of the electronic database MEDLINE. Reference list of eligible papers were also manually searched.     

Delusional misidentification syndrome and other unusual delusions in advanced Parkinson's disease

BackgroundUnusual delusional syndromes are rare protean diseases with speculative etiopathogenic mechanisms.MethodsSeven consecutive patients with advanced PD were evaluated over a 15-year period at the Movement Disorders Unit in the Neurology Service, Hospital de Clínicas, Federal University of Paraná, and the Paraná State Parkinson's Patients Association.ResultsWe describe advanced Parkinson's disease patients presenting with unusual delusional syndromes, including cases of Ekbom, Othello, Capgras' and Diogenes syndromes, reduplicative paramnesia and mirrored-self misidentification.ConclusionThere are a few isolated reports of unusual neuropsychiatric disorders in patients with PD. We believe that these syndromes associated with advanced PD in elderly patients presenting with cognitive impairment and polypharmacy are probably often underestimated. Neurologists should be aware for these rare and treatable conditions.     

Compensatory but not anticipatory adjustments are altered in older adults during lateral postural perturbations

ObjectiveThis study investigated anticipatory postural adjustments (APAs) and compensatory postural adjustments (CPAs) and their relationship in older adults during lateral postural perturbations.MethodsUnpredictable and predictable postural disturbances were induced by a swinging pendulum that impacted at the shoulder level of two groups of older adults, non-fallers (20) and fallers (20), and in a group of young control subjects (20). The electromyographic (EMG) activity of the postural muscles and the center of pressure (COP) displacement were recorded and quantified within the time intervals typical for APAs and CPAs.ResultsBoth groups of older adults (non-fallers and fallers) showed higher magnitude of EMG activity in the lateral muscles and increased COP displacement, particularly, during the CPAs time interval when compared to the young group. Older adults, however, were able to change the electrical activity of the muscles during the predictable task by generating APAs with similar magnitudes of those found in young subjects.ConclusionsCompensatory but not anticipatory adjustments are altered in older adults during predictable lateral postural perturbations.Significance: These findings provide new data on the role of APAs and CPAs in their relationship in older adults during external lateral perturbations and may advance current rehabilitative management strategies to improve balance control in older individuals.