مجله دندانپزشکی دانشگاه علوم پزشکی تهران
سال سی و یکم شماره 4 (پیاپی 97، زمستان 1397)

Glass ionomer cements are among direct restorative materials which are used in an environment saturated with moisture. Therefore, having the ability to prevent water contamination is crucial. The aim of this study was to determine the water sorption and solubility of five glass ionomer restoratives with and without two nanofilled resin coating agents. Five glass ionomer cements (Fuji BULK/GC, EQUIA Forte Fil/GC, Fuji II LC/GC, riva self cure/SDI, riva light cure/SDI) and two resin-based coating (G-COAT PLUS/GC and EQUIA Forte Coat/GC) were used in this study. Water sorption and solubility were measured in accordance with the ISO 4049's. For each material, 15 disc-shaped specimens were prepared using a polyethelyn mould. The specimens of each material were randomly divided into two groups: 10 coated and 5 uncoated. For the coated groups of each material, 5 specimens were coated with G-COAT PLUS, and 5 with EQUIA Forte Coat. Data were analyzed using SPSS software version 18 (SPSS Inc., Chicago, IL, USA). Two-way ANOVA was applied to investigate if there were any interactions between materials and coatings. One-way ANOVA was used to compare different variables between the materials, and post-hoc Tukey’s test was performed to show significant differences in subgroup comparisons. A significant interaction effect was obsevred between materials and coatings (P<0.05) using two-way ANOVA. The uncoated groups showed higher mean sorption and solubility values compared to the coated groups, and the groups coated by G-COAT PLUS showed less mean sorption and solubility values than that of EQUIA Forte Coat. In general, the lowest mean sorption and solubility values among glass ionomer cements belonged to Fuji BULK. The water sorption and solubility values of glass ionomer cements could be reduced by the use of a protective coating.

The aim of the present study was to evaluate the effect of applying hydrophobic resin after use of different generation of the bonding systems on nanoleakage. 20 third molar teeth were selected. The teeth were randomly divided into 4 groups of 5, each was treated using the fourth, fifth, sixth, and seven generation of dentin bonding. Then, the crown of teeth was sectioned from the CEJ region and each specimen was divided into two halves with mesiodistal cut, one half for the application of dentin bonding without the addition of a hydrophobic resin, and the other for the same dentin bonding by the addition of a hydrophobic resin. Afterwards, the specimens were restotred by composites. After placement of specimens in silver nitrate, the amount of nanoleakage was evaluated by SEM. Data were analyzed using a repeated measurement statistical analysis (α=0.05). The use of hydrophobic resins decreased nanoleakage and range of variations in all groups (P<0.05). This reduction was greater for total-etch dentin bonding. Higher degree of nanoleakage occurred in total-etch dentin bonding in most evaluated areas. In general, Clearfil S³ bond showed the least percent of the nanoleakage. All dentin bonding systems showed some degree of reduction in nanoleakage after hydrophobic layer application and the reduction was greater in Total-etch adhesives systems.

Methicillin-resistant Staphylococcus Aureus (MRSA) is an important infection source in dentistry for different disinfectants to be used to prevent its transmission. Furthermore, a variety of chemical disinfectants are developed to remove bacterial infections from the dental care workers' hands and claims are made regarding their superiority in infection control, although all requires scientific investigations. The aim of present study was to compare the effects of chemical hand-disinfectants Micro Zed HD, Aseptoman and Decosept on MRSA (methicillin resistant staphylococcus aureus) in different periods of time. In this experimental study, the antibacterial efficacy of three hand-disinfectants on standard strain of MRSA (USA300: ATCC® BAA-1717™) was evaluated according to European standard of evaluating antiseptics (EN 1040:2005 CSN EN). First we prepared a 0.5 Mc Farland (108 CFU/ml) suspension of MRSA, and exposed to three disinfectants for 15, 30, 60 and 90 seconds. Then, they were transferred to separate plates of Mueller-Hinton medium and incubated in 37◦C for 24 hours. The plates were compared then with control plate to evaluate the efficacy of materials on bacteria by calculating the CFU/ml of plates. Three hand-disinfectants evaluated in this study had the maximum anticabterial effect on MRSA in the minimum time of exposure (15 seconds), and we found no trace of growth in any plates. The three hand-disinfectans (MicroZed HD, Aseptoman and Decosept) in the concentration suggested by their companies, showed no difference in efficacy to remove MRSA from hands.

Despite the increasing application of intra-oral scanners, the effect of finish line position on gingival margins adaptation is still discussed. The purpose of this clinical study was to evaluate the fitness of cobalt-chromium copings obtained from intraoral scanning in two depth of finish lines. Thirty teeth prepared for single premolar metal-ceramic crowns were included. Fifteen teeth had supragingival and fifteen had sub-gingival finish lines. Digital impressions were made using an intraoral scanner (Trios-3shape). Computer-aided design and computer-aided manufacture (CAD/CAM) cobalt-chromium copings were fabricated from the scan files. The copings were evaluated intraorally and after adjustments, the internal and marginal discrepancy were measured using silicone replicas and a stereomicroscopy. Internal and marginal discrepancies were analyzed using the Multivariate test (P<0.05). The mean internal and marginal gap were 52.1 and 56.27μ, for supragingival group and 49.72 and 62.98μ for subgingival group, respectively. The evaluation of finish line position showed no significant effect on obtained results (P>0.05). CAD/CAM chrome-cobalt copings fabricated by digital impressions provided acceptable marginal and internal precision. However, the finish line position had no significant effect on the internal and marginal adaptation.

Trauma to primary and permanent teeth caused post-traumatic complications affecting the health of teeth and led to specific problems in treatment. As prognosis of trauma has closed correlation with immediate and correct management after occurrence of the incident and the health educators are the first people in contact with children in this places, their awareness of how to deal with these injuries plays an important role in prevention and treatment. This study aimed to evaluate the knowledge of health educators in confrontation with dental injuries in primary schools of Sanandaj in 2018. In this cross-sectional study, all of fifty-nine health teachers in primary schools of Sanandaj were identified after referring to education centre. The questionnaires were provided to the school health teachers after referring to schools and after completing questionnaires, collected data were analyzed. In order to test the research hypotheses, Multiple regression, Non-parametric tests of spearman correlation coefficient, Mann-Whitney and kruskal-wallis were utilized using SPSS software version 20. The mean knowledge score of fifty-nine health educators was 14.02±3.41 and knowledge score of females was higher. There was no significant statistical correlation between knowledge score, age,
work experience and education level (P>0.05). In this study, the knowledge score of experienced teachers in confrontation with injured persons and health educators who attended related training courses, was higher than others but this difference was not statistically significant (P>0.05). The results indicated inadequate knowledge regarding emergency management of dental trauma. Thus strategies to improve the teachers’ knowledge about dental trauma can positively influence their knowledge and attitudes toward emergency management of dental trauma.

Tooth decay is still one of the most prevalent pediatric diseases. According to the role of general dentists and importance of first dental visit in prevention, the aim of this study was to evaluate dentist’s knowledge and attitude regarding children’s first dental visit in Gorgan, Iran. In this cross-sectional study, 140 general practitioners participated. In order to assess the level of knowledge, a questionnaire including 2 parts was used as the main tool. Data were analyzed using Mann-Whitney, Kruskal-Wallis and Pearson correlation coefficient. Our findings revealed that the level of knowledge in both sex was equal (P=0.067). There was no significant relationship between the workplace (P=0.68), age (P=0.77), work experience (P=0.84) and the level of knowledge. Interest of practitioners to get the necessary training about examination and treatment of 0-2 year-old children was medium. 51.17% of dentists, admitted the treatment of 8-12 year-old children. 34.5% of dentists revealed that misbehavior of children during treatment was the main reason for unwillingness to accept treating them. 46.9% of dentists, revealed that the most effective result of child’s dental visit at an early age is increasing parents’ knowledge about prevention of carries in primary dentition. The results showed that general dental practitioners in this study had a good level of knowledge about the first dental visit. Regarding to their little tendency to treat children, it seems necessary to hold workshops and seminars for better desired motivation in this field.

One of the important fields of dentistry is surgery for dental implants. In this field, dentistry has developed considerably in recent years amongst other fields of medicine from the perspective of digital device and software application. Surgical guides help dental surgeon for more precise, confident, easier and shorter surgery. Process of producing these tools are full digital and to somehow complex due to the application of many technical devices, software and protocols. To achieve efficiency, all participants in the workflow must be aware of all steps and data requirements for production of guides. This paper investigates the production process of surgical guide comprehensively, and also, encompass all the steps in process with details. This review article was based on searching Google scholar and PupMed databases considering key words: Surgical Guide, Guided surgery, digital dentistry, dental CAD/CAM, Additive manufacturing. More than 90% of the references were in English language and published after year 2010. Today dentistry uses many digital solutions for dairy workflow and most of these solutions are developed by engineers in various fields of knowledge. Thus, this information is essential for dentists, surgeon, clinician and laboratory technician, etc. for better collaboration and participation. Amongst, advances in surgery of dental implant have been highly significant and patients benefit from better treatment and less inconvenience. In addition, dentists do surgery more precise and easier because of considering all conditions before of surgery. Thus, it is substantial inform of all steps of production process.

Lichen planus is a chronic inflammatory mucocutaneous disease with unknown etiology. One of the most common manifestations of patients with oral lichen planus is gingival involvement in the form of generalized erythematous areas. The aim of this study was to review the articles evaluating the role of plaque control on the gingival manifestations of oral lichen planus. Motor searches of Ovid Medline and EM base databases, PubMed, Google Scholar, and Science Direct were searched for article published between January 1990 and December 2017 using of relevant key words. After reviewing the abstracts of articles, 20 full articles were selected and among them, 7 relevant articles were reviewed in this study. From the literature, it was concluded that effective plaque control is the main part of lesions treatment and improvement of symptoms and gingival manifestations of oral Lichen planus.