s. haghanifar

There is a risk of damage to the inferior alveolar nerve when extracting third molars. A variety of common imaging modalities, such as panoramic radiography (PR) and cone-beam computed tomography (CBCT), are recommended for examination prior to mandibular third molar surgery. The aim of this study was to compare the findings of panoramic radiography and CBCT in evaluating the relation between the root of the mandibular third molar and the inferior alveolar canal.

In this cross-sectional study, 75 panoramic and CBCT images were evaluated. Cases in panoramic radiography that were suspected of the relation between the root of the mandibular third molars and the inferior alveolar canal were collected. To determine the type of connection of apex and root canal, the samples were divided into 6 groups: normal, inferior alveolar canal path loss, canal path narrowing, sudden canal path change, radiolucent band over the roots, and root curvature. Cases in the panoramic radiograph that were suspected of root contact with the canal were examined by the CBCT in terms of the position of the canal relative to the tooth (buccal or lingual or middle of the root - upper or lower) and the type of connection (whether the tooth is connected to the canal).

In panoramic findings, 23 cases (30.7%) were normal, 19 cases (25.3%) showed canal path loss, 9 cases (12%) canal path narrowing, 5 cases (6.7%) sudden canal path change, 3 cases (4%) radiolucent band over the roots and 16 cases (21.3%) showed root curvature. According to CBCT findings, the position of the canal relative to the root apex was lingual in 39 cases (52%) and there was connection between the mandibular canal and the third molar in 39 cases (78.7%). There was no significant relationship between panoramic radiographic and CBCT findings and only in two cases of specific radiolucent band over the roots, there was a complete agreement between panoramic and CBCT findings.

Based on the results of this study, if a radiolucent band is observed on the root of the mandibular molars or a sudden change is observed in the canal path, panoramic radiography can be used to detect the relation between the inferior alveolar canal and the root of the third molars.

It is essential to know the internal root canal anatomy to reach a successful root canal debridement and a subsequent successful root canal obturation. Due to the importance of knowing the complexity of mid-mesial (MM) canals and isthmuses and how to deal with these anatomic variations, in this study, we examined the incidence and prevalence of the MM canal and isthmuses in mandibular first and second molars.
In this cross-sectional study, cone-beam computed tomography (CBCT) records of patients presenting for diagnostic purposes to a radiology center in the city of Sari were used. A total of 207 mandibular first molars (81 males and 126 females) and 235 mandibular second molars (94 males and 140 females) were examined. Data were entered into SPSS 16 software. Descriptive data were presented using frequency percentage with the significance level of less than 0.05.
Among the mandibular first molars that were examined in the study population, the prevalence of the MM canal was reported to be 2.5% in males and 4% in females. Similarly, the prevalence of the MM canal in the mandibular second molars was reported to be 2.1% in males and 3.6% in females. Also, the prevalence of isthmuses was 81.2% (males) and 78.9% (females) in the first molars and 78.7% (males) and 70.7% (females) in the second molars.
Based on the results of this study, it is important for dentists to be familiar with the root canal anatomy and to consider the referral of complex cases to endodontists.

This study was conducted to evaluate the effect of treatment by Carboxin Thiram fungicide and Imidacoloropride pesticide on storability and some indicators of seed germination and vigor of maize single cross hybrid 704 in laboratory of department of agriculture at Islamic Azad University in Karaj. Seeds were prepared from Kermanshah Agriculture and Natural Resources Research Centre. Seeds were treated by pesticide, imidacloprid in two rates, 3 and 6 g per kg of seed, fungicide Carboxin Thiram in the 2 and 2.5 per thousand, and combined 3 g Gaucho + 2 per thousand Carboxin Thiraman and non- seed treatment were as a control. Treated seed and control seed stored at room temperature (25°c) 3 months. Then standard germination test was conducted and final germination percentage (FGP) was evaluated, normal seedling percentage and some related traits of seed vigor including seedling length, primary root and shoot length, root and shoot dry weight, seedling dry weight, seedling length and weight vigor indices were measured and the experiment was conducted as completely randomized design with 4 replications. The results showed that highest percentage of seed germination was related to treatments of imidacloprid 6 g and the lowest percentage of seed germination was related to control (non- seed treatment), the highest and lowest meantime of germination and control respectively Carboxin Thiram was 2 per thousand. The highest, the lowest weight and seedling vigor index of 2 per thousand treated by imidacloprid 6 grams and Carboxin Thiram. Therefore it can be concluded that seed sterilization as a method to prevent accelerated aging, is disinfectant to maintain and improve seed quality.

The use of dental radiography is inevitable in order for disease diagnosis, assessment and monitoring. Radiogeraphy is potentially harmful due to the use of ionizing radiation. This study was conducted to evaluate dentists’ knowledge about the principles of dental radiology.

This cross-sectional study was performed on 600 general dentists willing to cooperate with this study in Amol, Noor, Mahmoodabad and Sari cities located in Mazandaran province, Iran, in 2014. All the data were obtained by means of a questionnaire. The questionnaire included two parts; the first part surveyed demographic information, and the second part included 11 items about radiographic technique and equipments.

500 questionnaires were completed. Among the surveyed population, 335 (67%) and 165 (33%) dentists were male and female, respectively. The mean of practical experiences was 12.35±6.68 years. 469 dentists (93.8%) used the dental X-ray machine with digital timer and 404 dentist (80.8%) used the dental X-ray machine with long cone tube. Additionally, 470(94%) X-ray machine had round. Generally, 367 (73.4%) and 374 (74.8%) dentists used bisecting technique and E-speed films, respectively. Also, annual calibration of X-ray devices was suggested by 416 (83.2%) dentists.

According to our study, dentists’ knowledge about the dental radiography principles was fair.