فهرست مطالب m. mousavi nasab

One of the most important considerations in cavity preparation is undesirable encroachment to pulpo, that is sometimes evident and  touchable by catheter accompanied with bleeding and in some cases, it  is clinically unable to be distinguished. The dentist's  awareness of the remaining dentin thickness as well as presence or absence of microscopic exposures in the cavity can assist in selecting an appropriate treatment. The aim of this study was to determine the incidence of  pulp microexposures in deep class V cavities in the human premolars.

In this descriptive study, 30 human premolar teeth were used scheduled for extraction due to orthodontic reasons. After signing the consent form, deep class V cavities were prepared on the buccal surface of each tooth for amalgam restoration. Then the teeth were extracted and the roots as well as lingual portion of the teeth were sectioned. The samples were immersed in 2% methylene blue solution, then the presence or absence of microscopic exposure was evaluated in the axial wall using light microscopy. Besides, the remaining dentine thickness  was measured by a digital caliper. The study data were analysed using SPSS  software (ver, 16) via  ANOVA and T-test.

Presence of microscopic exposure was confirmed in one tooth (3.2%), and the mean remaining dentin thickness in all samples was 0.67mm.

In 96.8% of deep class V cavities without clinical symptoms, about 0.67 mm of dentin remained, which may be regarded as a good criteria to predict remaining dentin thickness.

Contamination of etched enamel to saliva before placement of sealant prevents the appropriate bonding and results in microleakage. Using bondings is effective for decreasing the microleakage. This experimental study aimed to evaluate the effect of bonding agent on microleakage of a fissure sealant before or after contamination to saliva.

In this experimental study 40 sound premolar teeth were randomly divided into four groups. The prophylaxis was done and the teeth were etched with 37% phosphoric acid gel, then they were washed and dried. In the first group, Seal-Rite fissure sealant and Dentastic (Pulpdent, USA) without saliva contamination, and in the second group sealant with bonding agent after saliva contamination for 10s, were applied and cured for 40s. In the third group, fissure sealant without bonding agent or saliva contamination, and in the fourth group fissure sealant without bonding application was applied after contamination with saliva and then was cured. After thermocycling, the teeth were placed in 50% silver nitrate for 2 hours. The buccolingual sections were applied and microleakage evaluation was made by stereomicroscope at 4X magnifications and results were evaluated with mann-whiteny test.

The fissure sealant group without bonding agent showed the most microleakage after contamination to saliva and use of sealant with bonding agent significantly showed decrease of microleakage.

Use of bonding agent under fissure sealant in saliva-contamination status is beneficial for decreasing microleakage.

Pectin is a hydrocolloid with different characteristics and applications. In this study, the cryoprotective effect of pectin on frozen surimi was investigated. In this research, Kapoor surimi was made for the first time in Iran. Surimi was mixed with 1% pectin solution with the ratio of 1 to 3 (w/v). Then, pectin-containing surimi samples and control samples were packaged, frozen and stored at -20oC. Water binding capacity (WBC), salt extractable protein and drip loss of samples were measured at after 0, 2 and 4 months of storage. The results showed that the loss of WBC in pectin-containing surimi and control samples was 20% and 58%, respectively, after 4 months storage at -20oC. It means pectin could improve the WBC up to 38% in the frozen product. The loss of SEP in pectin containing surimi samples was 21% and in control samples was 25% after 4 month frozen storage, indicating pectin was again effective in maintaining the quality of frozen products. Furthermore, the increase in drip loss in pectin containing surimi was about 7% and in control samples 37%. In this case pectin also helped to decrease the loss of water soluble nutrients. Overall, the results indicate that pectin as a cryoprotectant can improve the quality of frozen surimi.

Objective structured clinical examination (OSCE) is one of the preferable means of evaluating cognitive, emotional and psychomotor aspects of nursing students. The present study was designed to determine the reliability and validity of OSCE in evaluating clinical skills of nursing students.

For this descriptive study, 10 different skills of nursing students were selected. Then, 37 students performed these skills at 10 different OSCE stations, during which two experienced inspectors evaluated their performance. Finally, the correlation between OSCE scores and the mean theoretical and clinical performance scores of students was calculated. Meanwhile, the correlation between the total OSCE scores with OSCE score of each station was determined. Inspectors’ reliability (correlation between scores reported by inspectors at each station) was also calculated.

The correlation coefficient of OSCE scores and mean theoretical and clinical performance scores were 0.38 (p=0.031) and 0.52 (p=0.005), respectively. Correlation coefficient of inspectors’ reliability was in a range of 0.38-0.95.

OSCE is strongly suggested as a reliable and valid means of evaluating nursing students’ clinical skills.