henghameh zandi

The need to use a highly effective sealer in order to create a complete seal along the canal is essential for the basic treatment of tooth roots. Therefore, the aim of this study was to investigate the sealing ability of cold ceramic and gutta-percha with sealer by applying the bacterial leakage and electrochemical method.

In this in-vitro experimental study, fifty human single-rooted teeth were selected and their crowns were cut from the cervical region. The canals were prepared and washed with 17% EDTA. Then the teeth were randomly divided into four groups: group 1 gutta-percha with AH26 sealer (Dentsply Detrey, Germany) (n=20), group 2 cold ceramic (Yazd, Iran) (n=20), negative and positive control groups which each consisted of 5 teeth. Samples were kept in an incubator at 37° C for 48 hrs. Two coats of nail polish were used for covering the root, except for the last 2 mm, and microleakage in the fillings was measured by the bacterial leakage and electrochemical methods. The microleakage of the two groups was statistically analyzed in the electrochemical technique by Student's t-test, and in the bacterial leakage method by Fisher's exact test.

In bacterial leakage method, in the first group (gutta-percha) 7 samples (35%) and in the second group (cold ceramic) 3 samples (15%) had bacterial leakage, but no significant difference was observed between the two groups on different days (P>0.05). The mean microleakage based on the electrochemical technique in gutta-percha was significantly higher than that of cold ceramic (P=0.0001).

According to the lower microleakage values in the use of cold ceramic compared to gutta-percha, cold ceramic  can be used to fill root canals to reduce microleakage, although further studies are needed.

The association of oral micro-organisms with infectious diseases such as bacterial endocarditis is a concern in dentistry. Bacterial endocarditis is a serious disease with a mortality rate of 40%. The present study was conducted to investigate the effect of using chlorhexidine mouthwash on concentrations of some groups of bacteria in gingival sulcus, which is the main contact point of oral flora with circulating blood during scaling. In this Randomized controlled clinical trial, participants were selected among referrals to the department of gingival diseases of Yazd dental school. Participants underwent determining plaque index and after scaling, sampling of the buccal and lingual gingival groove of mandibular central and lateral teeth was performed by paper with walking movement. participants were 53 patients who divided into two groups. Group A consisted of 27 patients (15 women and 12 men) ranging in age from 21 to 54 years mean of 35) who used 50 mL chlorhexidine mouthwash and Group B consisted of 26 patients (13 females and 13 males) ranging in age from 19 to 51 years old with a mean of 35.76 who used 50 mL normal saline before scaling. Study groups were not significantly different in terms of age, sex and plaque index. (P-values= 0.755, 0.348 and 0.708)
Mann Whitney-Wilcoxon test compared the counted values of Streptococcus viridance and Staphylococcus aureus in control group was significantly higher than the study group. (P-value = 0.000) according to the results of our study chlorhexidine mouthwash prior to scaling teeth significantly reduced Streptococcus viridance and Staphylococcus aureus colony counts and could be recommended as a complementary agent for antibiotic prophylaxis in high risk patients prone to endocarditis, or as the only agent in moderate risk cardiac patients that antibiotic prophylaxis does not been used.

Microorganisms may be present in the form of spores, in honey. One of these dangerous organisms is the bacterium Clostridium botulinium spores which are capable induced botulism particularly in infants. The aim of this study was to determine the prevalence of Cl. botulinum spores in honey produced in different regions of Iran.
This cross-sectional study was performed in 2013. A total of 130 honey samples were collected and analyzed for Cl. botulinium spore. Samples were chosen randomly from the apiary of Iran. The samples were examined according to Iranian standard. In laboratory, honey samples were investigated using thermal shock and they located in cooked meat medium and incubated for 10 days at 35°C. The bacterium spores of Clostridium perfringens (PTCC: 1766) was used as a positive control sample.
The Results showed that Cl. botulinum spore was not detected in any of examined samples. Thirty four samples (26.67%) had mold and yeast contamination higher than the Iranian standard limit. Samples from Kurdestan province had high contamination (66.6%) and it was higher than other regions. Honey samples from Mazanderan province had the lowest prevalence of mold and yeast with ranged from 30 to 55 CFU/g.
Overall, the contamination of honey with Cl. botulinum spores in examined samples was zero and so they are safe, but some samples had mold and yeasts contamination that honey samples collected from west and north regions had the high and low contamination, respectively.