Caspian Journal of Dental Research

8-15

Authors: Sorour Soltani , Hossein Hessari , Reza Yazdani *

Introduction: Oral health can influence general health and then the quality of life. Regular toothbrushing with toothpaste plays a fundamental role in oral hygiene. The aim of this study was to assess the pattern of utilization of toothpaste among Iranian population. Materials & Methods: This cross-sectional study evaluated the family members of patients (n=715) presenting to dental clinics of School of Dentistry of Tehran University of Medical Sciences, in 2017. A researcher-made questionnaire was used to collect information regarding the pattern of utilization of toothpaste by the subjects. Data were analyzed using Chi-square test via SPSS 25. Results: Of all, 81% participants reported that they personally use toothpaste when toothbrushing and 75.9% stated that all the family members used toothpaste when brushing their teeth. Moreover, 57.2% reported that all the family members shared the same toothpaste; 86.6% reported that they started brushing the teeth of their children at the age of 3 years. When asked about the factors considered when for purchasing - toothpaste, the most important factors were the manufacturing country (42.5%), date of production (38.7%), having standard and authenticity labels (29.5%), the price (29.5%). Conclusion: According to the results, Iranian families have inadequate knowledge about the correct pattern of use of toothpastes.

26-34

Authors: Azadeh Majidian, Maryam Seyedmajidi, Hamid Abbaszadeh*, Majid Sharbatdaran, Sina Jafari, Hemmat Gholinia

Introduction: Oral lichen planus (OLP) is an immunologically mediated mucocutaneous diseases. Langerhans cells (LCs) are antigen presenting cells resident within oral mucosa which, together with intraepithelial lymphocytes, play a role in mucosal defense. The aim of present study was to determine the immunohistochemical expression of LC in Oral Lichenoid reaction (OLR) and OLP compared with normal oral mucosa (NOM). Materials & Methods: In this cross-sectional study, 61 oral mucosal specimens diagnosed histopathologically as OLP (n=31) and OLR (n=30) and 11 NOM were used to study the immunohistochemical expression of CD1a. The CD1a positive LCs in three regions (basal, suprabasal, and connective tissue) were counted in six randomly selected fields. Data were analyzed using the SPSS 24, T-test, ANOVA, LSD, Games-Howell tests. P<.05 was considered significant. Results: CD1a expression in OLP and OLR was significantly higher compared to NOM (P<0.001). CD1a expression in OLP was also significantly higher than OLR (P=0.009). There was a statistically significant difference between the three groups in basal, suprabasal and connective tissue regions (P<0.001). The mean of CD1a positive cells in the basal, suprabasal and connective tissue regions was significantly higher in the OLP group than OLR and NOM. Also, in comparison between OLR and NOM, the OLR group had significantly more CD1a positive cells (P<0.05). Conclusion: Increasing the number of CD1a in OLP and OLR compared with the NOM indicates the role of LC in the pathogenesis of these diseases.

42-49

Authors: Atefeh Gholampour , Ali Soleymani , Ali Bijani , Sina Haghanifar*

Introduction: Different materials cause artifacts in cone-beam computed tomography (CBCT) images, which, in turn, reduce the quality of images. The aim of this study was to investigate the abundance of artifacts induced by different root canal therapy sealers with two different CBCT resolutions. Materials & Methods: Roots of four maxillary central phantom teeth were prepared using rotary files in three steps. In the first step, the first tooth was scanned first without gutta-percha and then with gutta-percha No. 25. Gutta-percha No. 25 with resin, the zinc oxide-eugenol (ZOE)-based sealer and the ceramic-based sealer were placed in the teeth No. 2, 3 and 4, respectively. The second step was performed similar to the first step, except that gutta-percha No. 35 was used in the tooth No. 1 with resin- and ZOE-based sealers in the teeth No. 2 and 3. due to the lack of access to the ceramic-based sealer that was not used to continue the study . In the third step, canal obturation was performed in the teeth No. 2 and 3 with resin and ZOE-based sealers. At each step, three CBCT scans were obtained in high and standard resolution conditions. Contrast-to-noise ratio was obtained in three root plans, and the data were analyzed. Results: Gutta-percha alone produced more artifacts than gutta-percha with sealers. Moreover, ZOE-based sealers induced more artifacts than other sealers. There was no significant difference between the three steps. Similarly, at different resolutions, there was no significant difference between gutta-percha and sealer artifacts. The ZOE-based sealers had more artifacts at 1/3 apical whereas resin sealers had more artifacts at 1/3 coronal. Conclusion: The higher artifact of gutta-percha in comparison with gutta-percha and sealer and the artifact decrease in the combination of gutta-percha and resin-based sealer than ZOE-based sealer has led us to recommend the use of resin-based sealer while root canal therapy in order to better evaluation of the CBCT Images of root canal.

57-62

Authors: Reza Tavasoli , Akam Saeidi *, Elham Mahmoudi , Naeim Berijani , Hemmat Gholinia

Introduction: Root mineral trioxide aggregate (MTA) is a type of MTA that has been introduced in the Iranian market. There have been few studies on this substance. This study compared the push-out bond strength of Root MTA and CEM cement, which were both Iranian products. Materials & Methods: This in vitro study was performed on 20 extracted maxillary incisors. Samples were divided in two groups. The canals of the first group were filled with Root MTA and the second group by CEM cement. In order to investigate the push-out bond strength, the device applied a force in the direction parallel to the longitudinal axis of the sample so that the desired materials would fail. Each sample was classified into one of three types of failureincluding adhesive (failure in the material and dentin interface), cohesive (failure in the material itself) or a combination of both. Results: There was no significant difference between the mean pressure on teeth for the two groups (P>0.05). There was no significant difference between the frequencies of different types of failure between the two groups (P>0.05). Cohesive failure in the CEM group was twice as high as in the MTA group (P>0.05). Conclusion: There was not any significant difference between the push-out bond strength of CEM cement and Root MTA cement. These findings demonstrated that Root MTA material showed a satisfactory result in the bond strength test compared to CEM material, and could be used as an alternative to CEM cement.

71-78

Authors: Mahtab Banimostafa, Behnaz Esmaeili, Effat Khodadadi*, Soraya Khafri

Introduction: Glass ionomers are often used as a base under composite restorations in deep cavities by sandwich technique. The aim of this study was to compare the shear bond strength of composite to resin modified and conventional glass ionomer using total etch , self-etch and universal bonding systems. Materials & Methods: Ninety glass-ionomer samples were prepared for this research: Fuji II (F II), IonoStar Plus (IS) and Fuji II LC (F II LC).Then the specimens were divided into 9 groups (n=10). The surface of the specimens were prepared with three types of bonding: Adper single bond2 (SB), Clearfil SE bond (SE) and Single bond Universal (SU).Then Z250 composite resin was applied on the glass ionomers. The specimens were incubated in distilled water for 24 hours at 37 ° C and then were tested for shear bond strength. The type of failure was determined by a ×40 stereomicroscope and the results of the study were analyzed by nonparametric statistical analysis and Kruskal Wallis test. P≤0.05 was considered significant. Results: The highest shear bond strength was observed in the Fuji II LC + Single bond2 group. There was a statistically significant difference in the shear bond strength of the composite to the two glass ionomers F II and F II LC using SB and SU bonding systems (P=0.033 and P=0.040, respectively).There was no significant difference between the groups regarding the type of failure. Conclusion: Unlike the Fuji II LC and IonoStar Plus glass ionomers, the shear bond strength of the composite to the Fuji II conventional glass ionomer is affected by the type of bonding system. Total-etch and self-etch bonding systems can be used effectively in sandwich technique. Using a resin modified glass ionomer with total etch bonding can improve the shear bond strength of the composite to the glass ionomer.