Caspian Journal of Dental Research

Introduction: Growth and proliferation of the remaining microorganisms within the root canals may destroy the surrounding tissue of the root and leads to periapical lesion. Consequently, the complete elimination of microorganisms from the root canal is a n important goal of endodontic therapy. Endodontic sealers do not provide complete seal in root canal system, and micro spaces have always remained between the material and canal walls that lead to penetration of these spaces, so, an antibacterial activity is essential for sealers. The aim of the present study was the in vitro evaluation of antimicrobial activity of the three endodontic sealers on two microorganisms .

Methods: To study the effect of each sealer AH26, MTA Fillapex and ADseal on Enterococcus Faecalis and L actobacillus bacteria 10 samples were considered. In this experimental study, 60 plates were exposed to bacteria and 10 plates were considered for control group. Sealer antibacterial effect on bacterial growth was studied after 48 hours. Firstly, the freshly prepared sealers were poured inside the micro tube and diffused in the wall of the micro tube. Then solution of nutrient broth was poured into a micro tube and the determined volume of solution of bacterial suspension was added into a microtube and was kept 24 hours in the incubator to grow the bacteria. Then, it was poured in the plates of blood agar and cultured after 24 hours and then the colonies grown on the plates were counted in sufficient light. The data were analyzed with M ANOVA statistical test and SPSS Version 18.

Results: Most bacteria grew in the plates of ADseal sealer and MTA fillapex sealer with means of 5113.00CFU and 3077.00CFU respectively, while the lowest number of bacteria grew in the plates of AH26 sealer with a mean of 1345.15CFU.

Conclusions: Most antibacterial activities of each enterococcus faecalis and l actobacillus bacteria sample was for AH26 sealer and MTA fillapex sealer. The lowest antibacterial activity was for ADseal sealer.

Introduction:Noise in dental offices is one of the risk factors in the workplace. One of the major effects of noise is hearing loss. This study aimed to determine the effects of noise on hearing thresholds of dentists of Babol city.

Methods:This descriptive analytical cross-sectional study was performed on 40 dentists in Babol City (as case group) and 40 office workers (as control group). Hearing thresholdswere measured from all the subjects. The mean hearing threshold was calculated at different frequencies in each group and compared with the number 15 db. The data were analyzed by statistical software SPSS17and p≤0.05was considered significant.

Results:The mean and standard deviation of hearing thresholds for the right ear of dentists and the control group without considering the different frequencies were 13.6156±9.14210db and10.0156±5.4488db (P=0.036),respectively and for the left ear were12.5115± 8.7609db and 10.059 ± 5.9254db respectively. Hearing threshold of right and left ear of young and middle age dentists was not significant. The hearing thresholds of the dentists with work experience of 15 years or less were not significant for the right and left ear. Auditory thresholds were significant between male and female only for the left ear (P=0.02).

Conclusion:There was a change in hearing thresholds at all frequencies. A clear difference was in the left ear of men and women and hearing loss was higher in men. Also, age and working experience were not among the contributing factors to the incidence of noise-induced hearing loss.

 Introduction: Inhibiting the pain which affects both the patients and dentists is an important factor during treating dental patients. The aim of this study was to assess the analgesic effect of two medications ibuprofen and gabapentin on the post-endodontic-therapy pain.

Methods: Forty patients who need root canal therapy with Visual Analog Scale (VAS)>40, participated in this double-blind randomized clinical trial study and randomly divided into two groups. The ibuprofen group received 800 mg ibuprofen 1 hour before the treatment and 400 mg at 6, 12 and 24 hours after the treatment procedure, and the other group received 600 mg gabapentin 1 hour before the treatment and 300 mg at 6, 12 and 24 hours after treatment. Patients recorded the intensity of pain via VAS before treatment and every hour for the first 6 h after taking the medication and then every 6 h thereafter for a total of the 48-hour period. (Two tablets of acetaminophen codeine (325mg/20mg) were given to the patients as a rescue dose.

Results: The analgesic effect of gabapentin was significantly higher than ibuprofen in 12h (p=0.035), 24h (p<0.001), and 48 h (p=0.012) after analgesic intake. It has been also shown that both medicines had analgesic effect significantly. (p<0.0001)

Conclusions: Gabapentin had greater analgesic effects on the sample group from 12 h until 48h after taking in comparison with ibuprofen so it seems that it could be an appropriate option for postoperative pain inhibition.

Introduction: Root canal instrumentation is an important phase in root canal therapy. Since success in endodontic treatment depends on file defect and fracture, the aim of this study was to compare the evaluation of defect and fracture in rotary and reciproc files in severe curved root canals.

Materials & Methods: In this experimental study, 60 mesial canals of human closed apex molars with more than 30° canal curvature were randomly divided into two groups. In first group M-two rotary files number# 15, 20, and 25 and in second group R25 reciproc file were used for filing, respectively. A ×8 magnifier was applied to evaluate the defect or fracture presence in each side and if it were observed, a new file would be replaced. Therefore, the number of prepared canals with each file and fractured or defective files and the place of fracture in root canal were recorded. Kaplan Meier curve and log rank test were done by using SPSS v.22.

Results: In rotary group, seven and two files were fractured and defected, respectively and four files were fractured and no defect was observed in reciproc group. Although the mean of the number of prepared canals until fracture or defect in rotary and reciproc groups was 3.3 and 7.06, respectively, there were no significant differences between two systems. All file’s fractures occurred in apical regions .

Conclusion: The results showed that there was no significant difference in defects or fractures of rotary and reciproc systems. Reciproc instruments can be more effective than rotary ones because the root canal preparation in rotary instruments is longer than in reciproc system.