Caspian Journal of Dental Research

8-14

Authors: Pouya Abedi , Zahra Mohyadin , Sara Hosseini , Mehdi Abbasi *

Introduction: Residual oxygen-free radicals of bleaching agents before composite restorations can increase microleakage in enamel and dentin margins, and also various bleaching techniques are being developed using light sources. The present study was conducted to compare the effect of diode laser bleaching and LED activated bleaching on the microleakage of composite restorations. Materials & Methods: This in-vitro study was conducted on 84 extracted human premolars in three groups: In group one, class-V cavities were prepared and the teeth (n=12) were restored with composite ten days after bleaching with 35% hydrogen peroxide with no activator. In groups two and three (n=36 each), the teeth were bleached with a Diode laser activator and LED, respectively. Thereafter, each group was divided into three subgroups (n=12), cavities were prepared and restored with composite three, five, and ten days after bleaching. Digital photographs were used to assess microleakage in the enamel and dentin margins. Data were analyzed using Friedman and Wilcoxon Signed Ranks tests (p<0.05). Results: The lowest amount of microleakage in the enamel margin pertained to the diode laser ten-day subgroup (0.17±0.38) and the diode laser ten-day subgroup in the dentin margin (0.50±1.03). Also, the highest amount of microleakage in the LED group was in the three-day subgroup of the dentin margin (2.78±0.42). Five-day subgroup of diode laser-activated bleaching had a lower amount of microleakage compared to the control group (P=0.042). Conclusion: It may be concluded that diode laser-activated bleaching with 35% hydrogen peroxide has a better effect on reducing microleakage with an interval of five to ten days, compared to the control and LED activated bleaching group.

21-29

Authors: Farzaneh Mohammadi , Fatemeh Koohpeima , Mohammad Javad Mokhtari *

Introduction: Metal nanoparticles may apply to the cavity walls as acceptable antibacterial agents. The present work was conducted to assess the effect of silver nanoparticles (NPs) on the resin cements Shear Bond Strength (SBS) using one self-etch and one etch and rinse resin cement. Materials & Methods: Sixty intact noncarious extracted, human third molars were selected. All teeth were cut out in the middle of dentin thickness. Resin cement samples were randomly assigned to five groups: (A) Duolink cement without any further surface treatment; (B) Duolink cement with silver NPs (0.5%) dentin surface treatment after acid etching and before the One Step Plus (OSP) adhesive system; (C) Duolink cement with silver NPs (0.5%) dentin surface treatment before acid etching and OSP; (D) Panavia F2.0 cement without any further surface treatment; and (E) Panavia F2.0 cement with silver NPs (0.5%) dentin surface treatment. SBS was assessed by using universal testing machine. Then, human gingival fibroblasts (HGF) cells were treated with tested materials. The biocompatibility of resin cement was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. Results: The maximum and minimum of the SBS at the presence of silver NPs were observed in group E (15.81±0.91, P-value<0.01) and group B (12.01±0.15, P-value <0.05), respectively. In comparison with the controls, the resin cements incorporated with 0, 0.2% and 0.5% silver NPs, 20.34%, 22.00% and 22.67% for Panavia F2.0 and 36.84%, 37.34% and 38.17% for Duolink flow - decreased in total cell number, respectively (P-value<0.01). Conclusion: These findings demonstrated that Panavia F2.0 cement with silver NPs dentin surface treatment showed satisfactory result in the SBS compared to Panavia F2.0 cement without any further surface treatment.

38-45

Authors: Yasin Baghban , Imaneh Asgari *

Introduction: Demanding qualitative dental services calls for hiring competent staff in dental offices. This study was designed to evaluate dental assistants' educational status and ability to perform tasks. Materials & Methods: In this cross-sectional study, 200 dental assistants working in the offices and clinics of Isfahan, Iran during 2020 were selected using random systematic sampling. The researcher-made evaluation tool with a content validity index of 0.77 was used. Tasks were evaluated by 13 items in 6 sub-scales including communication skills, preparation, radiography, cooperation with dentists, health promotion through prevention and infection control. Moreover, information was requested about the education and training course of the dental assistant. The score of ability was achieved at the range of 0 to 20. The relationship between gender and training course as well as between age and experience level was evaluated with Mann-Whitney test and Spearman correlation. Results: The most frequent major of the study was accounting. The mean total ability score of the dental assistants was 19.1±6.5, ranging from 17.7 to 20. The highest and lowest ability scores were related to the cooperation with dentists and health promotion through prevention, respectively. The mean ability score had a weak relationship with age but had no significant relationship with experience. The mean ability score only in the area of radiography had a significant relationship with the training course and gender (P=0.012). Conclusion: Despite the diversity in the degree and field of study, the ability and task status of the assistants was desirable. In the area of health promotion through prevention, there is a need for training and monitoring its implementation.

56-63

Authors: Azadeh Zakariaee Jubari , Azadeh Torkzadeh *

Introduction: The maxillary sinuses are the largest paranasal sinuses adjacent to the teeth. Due to anatomical variations in different people, knowledge of these variations is essential for rhinoplasty and sinusitis. The aim of the present study was to determine the relationship between maxillary sinus volume with nasal septal deviation, concha bullosa and infundibulum size using cone-beam computed tomography (CBCT). Materials & Methods: In this descriptive -analytical study, CBCT images of 135 patients who underwent maxillofacial imaging were evaluated. In order to measure the volume of maxillary sinuses, CBCT images of axial sections were used with a thickness of 2 mm and Digimizer image analysis software. In the coronary section of nasal septum deviation, types of concha bullosa and infundibulum size were determined. Data were analyzed using one-way ANOVA, paired t-test, Pearson correlation test and regression. A value of P<0.05 was considered significant. Results: There was a significant inverse relationship between the mean of volume of the right sinus (p=0.012, r=-0.216) and left sinus (p<0.001, r=-0.303) with the deviation of the nasal septum. A significant inverse relationship was found between the mean volume of right maxillary sinus (p<0.012, r=-0.357) and left maxillary sinus (p=0.006, r=-0.357) with infundibulum size. The mean volume of right and left sinues from coronal view was not significantly different in the presence or absence of concha bullosa. There was no significant difference between male and female in the mean volume of the right and left sinuses. Conclusion: The present findings suggest that maxillary sinus volume is smaller the deviation in moderate and severe septal deviation cases and that the maxillary and with increasing size of infandibulum, the volume of maxillary sinus was larger.