Assessment of the systemic effects of low-level laser therapy (LLLT) on thyroid hormone function in a rabbit model.

The aim of this study was to assess the effects of low-level laser therapy (LLLT) applied to a dental extraction socket on thyroid gland function in a rabbit model, based on serum triiodothyronine and thyroxine levels. Sixteen male New Zealand rabbits were randomly distributed into two groups: a control group (non-irradiated animals) and an experimental group (irradiated animals: one irradiation point in the extraction socket of the lower incisor). Animals in the experimental group were irradiated with an aluminium gallium arsenide diode laser (AlGaAs; wavelength 830 nm, 40 mW, CW laser), for 13 days, every 48 h, at a dose of 6 J/cm(2) per session, resulting in a total dose of 42 J/cm(2). Serum triiodothyronine and thyroxine levels were measured in both groups before extraction and on the last day of observation (day 15). There were no statistically significant differences between the groups in pre- and post-irradiation triiodothyronine and thyroxine values. With the irradiation protocol used in this study, LLLT did not affect thyroid function in rabbits as assessed by circulating serum triiodothyronine and thyroxine levels.

Scanning electron microscopy analysis of two methods of root-end preparation.

AIM: This study evaluated changes in dental tissues of the apical third after root-end preparation. METHODS: Sixty permanent single-rooted human teeth were used after apicectomy at 90 degrees to the long axis of the tooth. Crown removal was performed with a double-faced diamond disk, on a straight handpiece, and specimen standard length was set at 8 mm. Root-end cavities were prepared with an ultrasound system in 30 teeth (G1); in the other teeth, the cavities were prepared with a bur using a contra-angle and micro-handpiece (G2). The width of the root-end cavity was the diameter of the tip or bur, and its depth was 3 mm. Each group was divided into two subgroups with 15 teeth each; 37% phosphoric acid was applied to specimens in subgroups G1B and G2B. All specimens were photographed under scanning electron microscopy. Images were evaluated descriptively and data were compared for fractures, smear layer, uniform inner surface, regular edges, and whether root-end preparation including the whole foramen. A chi-square test and the kappa index were used to analyze results statistically. RESULTS: Only two variables, uniform inner surface and regular edge, varied according to the method used (bur or ultrasound). The presence of smear layer was associated with the use of phosphoric acid. CONCLUSION: Both methods seemed to be adequate for use in endodontic surgeries.

Marginal adaptation and microleakage of five root-end filling materials: an in vitro study.

AIM: Endodontic surgery consists of several procedures which involve the endodontic space or the root canal and is performed as an alternative to unsuccessful outcomes or complications following endodontic treatments. The aim of the study was to evaluate the sealing ability of five root-end filling materials. METHODS: Fifty human single rooted teeth were treated endodontically; roots were resected at 3 mm from the apex, and root end cavities were prepared with ultrasonic tips. Root ends were filled with one of the following materials: silver amalgam (control group); mineral trioxide aggregate; white Portland cement; Vitremer; and Fuji Ortho. Apical sealing was evaluated by evaluating microleakage of 50% silver nitrate solution. The apical portion of the roots was sectioned to obtain 1-mm thick transversal slices, and epoxy resin replicas of these apical slices were produced. A scanning electron microscope (SEM) was used for analyses. The Kruskal-Wallis test and a multiple comparisons test were used for statistical data analysis. RESULTS: Results showed microleakage and variable adaptation gaps on the interface between dentin and root-end filling material in all specimens. CONCLUSION: All the studied materials exhibited some degree of apical microleakage and marginal gaps. No correlation was found between data obtained from analyses of apical sealing and marginal adaptation.

Delirium: current trends in prevention and treatment.

Delirium is a disturbance of consciousness, cognition and perception that occurs frequently in medically ill patients. Although it is associated with increased morbidity and mortality, it is often not recognised and treated by physicians. Predisposing factors are believed to have multiplicative effects and include dementia, advanced age and male gender. Recently developed models allow for the estimation of the risk of developing delirium during a hospitalisation, based on predisposing factors and acute additional stressors. Although it has been shown to be efficacious, the prevention of delirium is underutilised. Prevention consists of aggressive management of known risk factors and early detection. Limited data exist to support specific pharmacological interventions for its treatment. In this article, the avail-able published literature regarding the prevention and treatment of delirium is systematically reviewed.

Branched chain amino acids decrease tardive dyskinesia symptoms.

RATIONALE: Prior studies had suggested (a) that a lessened ability to clear ingested forms of the large neutral amino acid (LNAA), phenylalanine (Phe), was associated with having tardive dyskinesia (TD), and (b) that greater availability of a group of LNAA, the branched chain amino acids (BCAA), concomitant with the lower availability of Phe to the brain are associated with a decrease in TD symptoms. The present study was then conducted to test whether increasing the daily intake of the BCAA would decrease the symptoms of TD. METHODS: A 2-week trial of a BCAA medical food administered three times a day was conducted in nine men with long neuroleptic treatment histories. Frequency counts of TD movements were collected by videotape throughout the trial and these tapes were analyzed in blind random sequence for both patient and time for TD symptom level changes subsequent to completion of the trial. Plasma levels of the LNAA were also collected throughout the trial. RESULTS: A statistically significant decrease in the level of TD symptoms was observed for the sample. The symptom changes were also clinically significant in that six of the nine subjects had symptom decreases of at least 58%, with all subjects having a decrease of at least 38%. BCAA administration increased plasma BCAA concentrations and BCAA/LNAA ratios and decreased plasma Phe concentrations and the Phe/LNAA ratio. Analyses indicated a strong significant correlation between the percent increase in the plasma BCAA values at the first administration and the percent improvement in TD over the trial in eight of the nine subjects. CONCLUSIONS: The BCAA show promise as a treatment for TD. The decrease in TD symptoms seen in the trial may have been modulated by the BCAA treatment-induced increased availability of the BCAA and decreased availability of Phe to the brain.

Availability of a cationic herbicide adsorbed on clay minerals to cucumber seedlings.

Montmorillonitic and kaolinitic clays are effective in decreasing the toxicity of paraquat, an organic cation, to cucumber plants. The cation was adsorbed on the surface of the kaolinite clay particles and slowly became available to the plants. When it was adsorbed in the interlayer spacings of the montmorillonite clay, however, it was not available to the plants.