Characterization and surface treatment effects on topography of a glass-infiltrated alumina/zirconia-reinforced ceramic.

OBJECTIVE: Characterize the microstructure, composition and some physical properties of a glass-infiltrated alumina/zirconia-reinforced ceramic (IZ) and the effect of surface treatment on topography. METHODS: IZ ceramic specimens were fabricated according to ISO6872 instructions and polished through 1 microm alumina abrasive. Quantitative and qualitative analyses were performed using scanning electron microscopy (SEM), backscattered imaging (BSI), electron dispersive spectroscopy (EDS) and stereology. The elastic modulus (E) and Poisson's ratio (nu) were determined using ultrasonic waves, and the density (rho) using a helium pycnometer. The following ceramic surface treatments were used: AP-as-polished; HF-etching with 9.5% hydrofluoric acid for 90 s; SB-sandblasting with 25 microm aluminum oxide particles for 15s and SC-blasting with 30 microm aluminum oxide particles modified by silica (silica coating) for 15s. An optical profilometer was used to examine the surface roughness (Ra) and SEM-EDS were used to measure the amount of silica after all treatments. RESULTS: The IZ mean property values were as follows: rho=4.45+/-0.01 g/cm(3); nu=0.26 and E=245 GPa. Mean Ra values were similar for AP- and HF-treated IZ but significantly increased after either SC or SB treatment (p相似文献   

Dyes for caries detection: influence on composite and compomer microleakage

The aim of this study was to evaluate the influence of caries-detecting dyes on the microleakage of adhesive materials. Sixty cubic class V cavities were prepared on buccal and lingual surfaces of 30 human third molars. Coronal margins were located in enamel and gingival margins in cementum. The teeth were randomly divided into six groups of ten restorations each. Cavities were restored with an adhesive system (Single Bond, 3M ESPE, St. Paul, Minn., USA), a compomer (F2000, 3M ESPE), or a composite resin (Z100, 3M ESPE) according to the manufacturer's directions. Acid red dye (Seek, Ultradent, South Jordan, Ut., USA) and basic fuchsin dye (Vide Cárie, Inodon, Porto Alegre, Brazil) were tested. Control groups were prepared without the use of dyes. After 7 days of storage in distilled water, the restorations were polished and the teeth were subjected to thermal cycling followed by immersion in 2% methylene blue. The teeth were sectioned, and microleakage scores were evaluated under magnification (40x). Data were submitted to statistical analysis using the nonparametric Kruskal-Wallis test. A statistically significant difference ( P<0.05) in microleakage was found between the materials in cementum (Z100>F2000) but not in enamel. Control and experimental groups using dyes showed similar results. It was concluded that dyes for caries detection did not increase microleakage of the adhesive materials tested.     

Health-related quality of life of maltreated children and adolescents who attended a service center in Brazil

Purpose

This study’s aim was to evaluate the health-related quality of life (HRQoL) and associated factors of maltreated children and adolescents.

Methods

This cross-sectional study consisted of individuals between 8 and 17 years of age who were victims of maltreatment. The KIDSCREEN-52 was used to measure their HRQoL. Socioeconomic and demographic data were collected, as well as information about the type of abuse, type of perpetrator, and psychological support adherence. The Kruskal–Wallis test was used to analyze the scores of the KIDSCREEN-52 by the independent variables.

Results

One hundred and thirteen victims answered the questionnaire. Girls and adolescents had a lower overall HRQoL score (p?<?0.05). Children who suffered from sexual abuse had a lowest score on the moods and emotions dimension than children who suffered from physical abuse (p?<?0.05). There was a lowest score on the autonomy dimension among the children who suffered maltreatment by an extrafamilial perpetrator than those who were victimized by an intrafamilial perpetrator (p?<?0.05). A lower score on the psychological well-being was observed among the children who adhered to the psychological support program provided by the service compared to those who terminated the service before completion (p?<?0.05).

Conclusions

Adolescents and girls were associated with lower HRQoL scores. There was no association between the overall HRQoL score and the characteristics of the maltreatment; however, the type of abuse and the victim’s relationship with the perpetrator were only related to some dimensions. These findings may assist maltreatment care providers in planning strategies to reduce the consequences that violence may cause.

     

A double‐blind randomised clinical trial of two techniques for gingival displacement

Knowledge about security and the potential damage originated by the gingival displacement techniques has not been described through randomised clinical studies. This crossover, double‐blind, randomised clinical trial evaluated clinical and immunological factors related to conventional and cordless gingival displacement (GD) techniques, and patients' perceptions in 12 subjects with the employment of 2 GD techniques: conventional (gingival cord + 25% AlCl3 astringent gel) and cordless (15% AlCl3 astringent‐based paste). In each subject, two anterior teeth were treated and a 10‐day wash‐out period separated the two treatments. Periodontal indices were evaluated before (baseline) and 1 and 10 days after GD. Interleukin 1β, interleukin 6 and tumour necrosis factor α concentrations in gingival crevicular fluid were measured before and 1 day after GD. Subjective parameters (pain, unpleasant taste and stress) were also evaluated. Data were analysed by one‐way repeated‐measures analysis of variance and Tukey's test (immunological factors), the Friedman test (periodontal parameters) and Fisher's exact or chi‐squared test (subjective parameters), with a significance level of 95%. Gingival bleeding index, probing depth and plaque index values did not differ significantly between groups at any timepoint. Neither technique resulted in worse periodontal indices. Both techniques yielded similar results for pain and unpleasant taste, but conventional GD was significantly more stressful than cordless GD for volunteers. Both treatments significantly increased mean concentrations of the three cytokines, with the conventional technique producing the highest cytokine levels. Cordless GD is less stressful for patients and results in lower post‐treatment levels of inflammatory cytokines compared with conventional GD.     

Autoimmune thyroid disease and chronic urticaria

We report six cases of autoimmune thyroid disease associated with chronic urticaria and briefly review the literature, including the histopathological nature of such lesions, and their aetiology and pathogenesis. In view of the prevalence of thyroid disease in patients with chronic urticaria, screening measurements of thyrotropin and anti-thyroperoxidase antibodies are recommended, although negative antibodies do not exclude a relationship between urticaria and thyroid autoimmunity. After failure of conventional therapy for urticaria, patients who are apparently clinically euthyroid may be considered for a trial with levothyroxine. Improvement of urticaria was seen with levothyroxine treatment in three of four patients with only marginal abnormalities in thyroid function.