Journal of Islamic Dental Association of IRAN
Volume:29 Issue: 4, Autumn 2017

It has been shown that anaerobic and capnophilic bacteria play an important role in implant failure and loss. The present study is an in vitro research aimed to investigate the antibiotic resistance of Aggregatibacter actinomycetemcomi-tans (Aa) and Porphyromonas gingivalis (Pg) in peri-implantitis lesions of Iranian pa-tients and to find laboratory efficiency of some antibiotic on these two bacteria.
In this antibiogram study, the plaque samples were obtained from peri-implantitis lesions from patients who referred to implant center of Faculty of Dentistry of Tehran University of Medical Sciences. Nine samples incubated in Aa-specific culture media and 9 samples incubated in Pg-specific culture media under anaerobic and capnophilic conditions. After 48 hours, colonies were verified by microscopic and biomedical examination, and a colony-counting device. Then the specimens were cultured in the specific culture media for antibiogram evaluations by measuring the diameter of growth inhibition zone of antibiotic standard disks of amoxicillin, co-amoxiclav, metronidazole, tetracycline, clindamycin, and ciprofloxacin.
There was no statistically significant difference (P=0.74) between the colony count of Aa (84.56±16.65) and Pg (87.67± 21.49). Most of growth inhibition zone ranged between 10 and 35 mm. The Pg specimens were significantly more resistant to studied antibiotics (P0.05) compared to Aa. However, both groups had similar resistance to amoxicillin and tetracycline, P-values were 0.22 and 0.13 respectively.
A large number of peri-implantitis lesions contain Aa and Pg bacteria. Moreover, the majority of Aa samples were sensitive to the applied antibiotics, while almost all Pg specimens were resistant to them.

Oral health literacy plays an important role in oral health promotion. This study aimed to assess the level of oral health literacy of senior medical and pharmacy students.
This cross-sectional study was conducted on senior medical and pharmacy students (n=300) of Tehran University of Medical Sciences in 2015. The oral health literacy-adult questionnaire (OHL-AQ) was used for data collection. This questionnaire has 17 items in four sections. The first section relates to the assessment of the perception of oral health. The second section is for the assessment of the ability to calculate values related to antibiotic and mouthwash prescriptions. The third section assesses the efficacy of communication skills, and the fourth section is about decision-making with regard to oral health problems. Chi-square and linear regression were used for descriptive analyses.
The mean score of oral health literacy was 12.093.85 for medical students and 10.484.29 for pharmacy students. University degree of the father (P Considering the moderate level of oral health literacy of medical and pharmacy students, it is necessary to include oral health topics in the curricula of medi-cal and pharmacy schools.

Bacterial colonization occurs following contamination of impression materials with blood and saliva. However, not all disinfecting agents are compatible with the impression materials and may cause changes in the resultant casts. The purpose of this study was to assess the impact of various immersion time of addi-tion silicon impressions in different disinfecting solutions on the surface hardness and detail reproduction of gypsum casts.
In this in vitro experiment, 84 addition silicone impressions were divided into seven groups (n=12). One group served as the control and the other groups were disinfected with 1% sodium hypochlorite, 2.4% glutaraldehyde, and 5% povidone-iodine for 5 and 30 minutes. Impressions were poured with type IV dental stone. The Knoop hardness value (KHN) was measured by microhardness tester. Surface detail reproduction, casts were inspected under a light microscope at X10 magnification. The surface hardness data was analyzed using two way ANOVA, Tuk-ey`s test, Dunnett`s, One way ANOVA and t-test. The detail reproduction results were analyzed using the Kruskal-Wallis test.
Immersion in povidone-iodine for 5 minutes and in sodium hypochlorite and glutaraldehyde for 30 minutes significantly lowered the KHN of resultant casts (P=0.001). No other significant differences were noted (P>0.05). No significant difference was found in detail reproduction between groups (P>0.05).
Increasing the immersion time of impressions in povidone-iodine increased the hardness of casts. Thus, 5% povidone-iodine is a more suitable disinfecting solution for longer immersion time given that other properties of the casts are not affected.

Identification of the factors that affect early dental caries has an important role in health planning in different societies. This study was conducted to evaluate the effect of different factors on early caries in deciduous teeth.
This cross-sectional study was conducted on 603 children aged 3-5 years in Tehran during 2013-14. Multistage stratified random sampling was done in the northern, southern, eastern, and western regions of Tehran. Data were collected by dental examination and by using a questionnaire answered by the parents. The Poisson regression analysis was used for evaluating the correlation between the independent variables and the results, while the structural equation modeling (SEM) method was applied to evaluate the joint effect of these factors on dental caries indices.
The mean and standard deviation (SD) of the decayed-missing-filled-teeth (dmft) and decayed-missing-filled-surfaces (dmfs) were equal to 6.45±4.02 and 11.62±10.61, respectively. The effects of body mass index (BMI) and the latent varia-bles of poor eating habits and oral hygiene on the dmft and dmfs were significant (P Dental caries is associated with poor eating habits, oral hygiene, and BMI. These factors can be modified and corrected through public health approaches such as providing counseling services, defining the principles of health behaviors, and teaching proper eating habits to parents and children.

Different methods and materials are available for post and core (P&C) fabrication. We aimed to compare the fracture resistance and failure modes of endodontically treated maxillary central incisors restored with six different P&C systems.
In this in-vitro study, after endodontic treatment and coronal preparation of 60 maxillary central incisors, six different P&C systems were used: 1) cast base metal P&C, 2) cast gold alloy P&C, 3) zirconia post and casting ceramic core, 4) zirconia post and composite core, 5) titanium post and composite core, and 6) fiber post and composite core. Thermocycling (5-55°C, 60 seconds, 1500 cycles) was performed after cementing the full metal crowns on each tooth. A 130° force was ap-plied at a crosshead speed of 1.5 mm/minute in a universal testing machine. The frac-ture force (N) and fracture patterns were recorded. Data were statistically analyzed by using Kruskal-Wallis, Mann-U-Whitney, and Fisher’s exact tests (α=0.05).
The highest mean fracture resistance was recorded in the first group (904±302.77 N) followed by the third group (725±202.11 N), second group (723±224.15 N), fourth group (675±358.64 N), fifth group (424±156.85 N), and sixth group (416.5±81.58 N). The groups with casting P&Cs and zirconia post and casting core showed significant differences with the other two groups with non-casting cores (P The highest fracture resistance was recorded for cast metal P&C, which may be due to a better stress distribution. Zirconia post and ceramic core may be a proper and aesthetically appealing substitute for cast metal P&C.

Mucoceles are described as asymptomatic benign soft tissue masses of the oral cavity. They are soft, smooth, spherical, translucent and fluctuant in the clinical appearance. The most common site of the mucocele is the interior surface of the lower lip followed by the tongue, floor of mouth (ranula), and the buccal mucosa.
Case Reports: This is a case of a 2-year-old girl referred to the Department of Pediatric Dentistry at Shahid Beheshti University of medical sciences with a soft tissue swelling on the lower lip appeared at birth. Typical clinical signs and features along with pathology report lead to the diagnosis of a mucocele. Surgical excision was carried out as the treatment of choice with the histopathological sample being provided for the lab. A spilled mucin surrounded by fibrovascular connective tissue was the lab report. Soft tissue healing of the surgical site was observed with no scaring in a week follow up.
Clinical signs and histopathological report were indicative of a mucocele.