Caspian Journal of Dental Research

8-16

Authors: Mitra Tabari, Ziba Nourali, Soraya Khafri, Samane Gharekhani, Iman Jahanian*

Introduction: Evaluation is a critical issue to achieve the goals of academic education. The aim of this study was to evaluate the achievement level of educational objectives in Babol dental school using the CIPP (content, input, process, and product) model based on the point of view of students. Materials &Methods: This cross-sectional study was performed using a researcher made questionnaire based on CIPP model for three educational groups of pediatrics, orthodontics and restorative dentistry among dental students accepted in 2008 and 2009. Total scores were calculated for each field and categorized as undesirable, relatively desirable and desirable with scores below 50, 51-70 and 71-100, respectively. Statistical analysis was performed using ANONA, T-test and Tukey HSD tests and p<0.05 was considered significant. Results: The mean scores were desirable in all groups. Mean scores allocated to the content, input, process and product areas were not significantly different in the pediatrics, orthodontics and restorative dentistry groups. Conclusion: Based on the student’s point of view, the pediatrics, orthodontics and restorative dentistry departments of Babol dental school were successful in achieving educational goals.

24-29

Authors: Ali Dodani, Sepideh Siadati, Jahanshah Salehinejad, Karimollah Hajian-Tilaki, Hamid Abbaszadeh-Bidokhty *

Introduction: Differentiation of fibroblasts to myofibroblasts is an initial and very important event in tumor genesis. Myofibroblasts produce proteinases that stimulate invasion in cancers. Due to the more malignant potential of oral squamous cell carcinoma (OSCC) compared to cutaneous squamous cell carcinoma (CSCC) , the aim of the present study was to compare myofibroblasts between OSCC and CSCC to understand whether myofibroblasts can help more malignant potential of OSCC compared to CSCC or not. Materials &Methods: This cross-sectional study included 40 cases of OSCC and CSCC and 20 cases of normal skin and normal oral mucosa. Then, 4-micron sections of paraffin-embedded tissue blocks of studied groups were stained immunohistochemically with α-SMA antibody. Mean percentage of myofibroblasts was calculated in invasive fronts of OSCCs with CSCCs and also in normal samples and staining intensity of cells for α-SMA marker and distribution pattern of myofibroblasts were determined. Results: The differences of average percentage of myofibroblasts in OSCC and CSCC compared to normal groups were significant (Pvalue= 0.007 and Pvalue=0.003 respectively), but when we compared OSCCs and CSCCs, the difference was not significant. Also, there were no significant differences between OSCC and CSCC with regard to staining intensity and pattern. Conclusion: Different biologic behavior of OSCC compared to CSCC doesn’t depend on myofibroblasts and other factors can be involved.

37-43

Authors: Neda Babaee, Hamed Kazemi, Seyed Ali Asghar Sefidgar, Ali Bijani, Mehdi Pouramir, Hadi Mortazavi *, Nafiseh Ghasemi

Introduction: Alpha amylase is the most abundant enzyme of parotid gland. This enzyme starts digestion of carbohydrates in the mouth. A pair of parotid glands is located in front of ears. Several studies have been conducted on the effects of mobile phones on the parotid gland. The aim of this study was to investigate the effects of mobile phones on the activity of the amylase enzyme. Materials &Methods: Totally, 251 men and women aged 18 to 55 years, who only used Hamrahe Aval's operator were included. Parotid salivary samples of each individual were bilaterally collected using capillary tube placed in the vicinity of Stensen's duct. Bilateral amylase activity of each individual was evaluated with spectrophotometric method in the laboratory considering dominant sides of phone conversation and chewing. Data were analyzed using Two-way ANOVA, χ2, T test and SPSS software. Results: The relationship between the dominant phone conversation side and parotid amylase activity was not statistically significant but the correlation between prevailing chewing side and amylase activity was statistically significant (p=0.001). Conclusion: Handheld mobile phone was not effective on parotid amylase enzyme activity whereas chewing was effective on parotid amylase enzyme activity.

50-58

Authors: Sayed-Mostafa Mousavinasab, Arman Salehi *, Negar Salehi

Introduction: The present study was performed to evaluate the effects of light-curing modes and shades of methacrylate and silorane-based composite resins on temperature rise during polymerization of composite resins. Materials &Methods: In this in vitro study, ninety composite samples with two types of composite resin - methacrylate-based and a low-shrinkage silorane-based were prepared, in 3 groups (30 samples in each group), Group 1: Filtek Z250 (shade A3), Group 2: Filtek Z250 (shade B2) and Group 3: Filtek P90 (shade A3). To evaluate temperature changes, 15 samples and the other half were light-cured using the standard and soft start curing modes for 40 seconds, respectively. A k-type thermocouple was used to recorded temperature changes. Results: Temperature rise in the silorane-based composite resin group (group 3) was higher than that in the methacrylate-based one (group 1) (P<0.001). Temperature rise with the darker shade (group 1) was higher than that with lighter shade (group 2) (P<0.001). Standard curing resulted in more temperature rise compared to soft start curing; however, the difference was only significant in group 2 (P<0.001). In all groups, temperature increased with an increase in curing time and the temperature rise pattern during the first 10 seconds with the soft start curing was not consistent with the standard curing (in group 2 and 3); the temperature rise pattern was milder than the soft start curing (P<0.001). Conclusion: Factors such as composite resin type, shade and curing mode affected temperature changes in composite resins evaluated in the present study.