مقالات رزومه دکتر محمد مهدی یاقوتی خراسانی

To be successful in root canal therapy, the dentists must be aware of the possible variation in the root canal and should know not only the natural anatomy of the pulp, but also a variety of possible morphologies. Frst of all, the dentists should be familiar with the possible anatomy of the root canal and then with the extraction of organic tissue from pulp chamber and root canal, increasing the chances of treatment success. Therefore, in this study, we decided to investigate the internal anatomy of root canals in the maxillary permanent molar teeth in Khoy city.

In this in vitro study, 100 extracted human molars in Khoy city in West Azerbaijan province were collected. In all teeth, the access cavities were prepared, then they were decalcified and colored with India ink and evaluated by clearing technique. Data were collected based on Vertucci's classification which entered into SPSS23 software. The descriptive statistics in the form of numbers and percentages in tables and graphs were used to analyze the data.

The most common type observed in the mesiobuccal root of the first molars was type IV by 44%, in distobuccal root was type I by 92%, and in palatal root was type I by 94%. Also, in the mesiobuccal root of the second molars, the most common type was type I by 70%, in distobuccal root was type I by 94%, and in palatal root was type I by 96%.

The mesiobuccal root of the first molar had the most variation in the internal anatomy. Also, the most common type of Vertucci in the mesiobuccal root of first molar was type IV and in the other roots of the first and second molar teeth was type I.

Due to the association of post- and pre-endodontic pain, using non-steroidal anti-inflammatory drugs (NSAIDs) before root canal therapy could interfere with the subsequent inflammatory process and reduce post-endodontic pain. The present study aimed to compare the effectiveness of prophylactic gelophen, Advil (two types of NSAIDs), and placebo in controlling the pain after root canal therapy.
This triple-blind clinical trial was conducted on 48 patients with a vital, single root canal anterior tooth. The teeth samples were divided into three groups. The patients in each group received one capsule as pre-treatment prophylaxis, which contained gelophen, Advil or placebo depending on the codes. Standard root canal therapy was performed by a general dental practitioner. Level of pain in each patient was recorded before the treatment and at 6, 12, 24, 48, and 72 hours after the treatment using the visual analog scale (VAS). After collecting the data, mean pain score was compared in the study groups. Data analysis was performed using Chi- square and repeated measures ANOVA.
In the patients administered with Advil and gelophen, pain reduction was more significant than the placebo group at all the intervals after the treatment compared to the pre-treatment phase. However, no statistically significant difference was observed between the intervals in this regard (P>0.05).
According to the results, the prophylactic use of Advil and gelophen is effective in the reduction of post-endodontic pain, while there is no significant difference in their efficacy.

Inappropriate behaviors in academic environments can strongly disturb both teaching and learning processes and make conflict and anxiety between instructor and student. The main objective of this study was to investigate student's attitude on inappropriate behaviors in academic environments.
This research was a cross-sectional descriptive study conducted in 2012. A questionnaire was designed by the researcher and all students of Faculty of Dentistry voluntarily participated. Data was analyzed using SPSS18 software, descriptive, independent T, ANOVA, and Spearman’s correlation coefficient; P ≤ 0.05 was considered significant.
Results of this study indicated that the majority of students considered sleeping in class as an inappropriate behavior, while checking the time at the end of class was the most common behavior which was reported by them. A significant relationship was observed between students’ perspective on inappropriate behaviors and the manner they did them; as Spearman statistical test indicated a high correlation between their perspective and frequency of inappropriate behaviors (R = 0.55 and P = 0.0001).
Findings indicated that the majority of students had a negative attitude towards inappropriate behaviors. Besides, the frequency of doing these behaviors cannot be justified by this research team. Regarding the negative effects of inappropriate behaviors on education process, it is recommended to take some actions for cherishing instructors and students in academic environments.

Bacteria and their products have an important role in root treatment failure and their continued presence in seemingly well-filled canals, cause disturbances in healing process after the treatment. Thus the use of proper disinfectants for mechanical cleaning of canals has a great importance. Nowadays, scientists are seeking better alternatives with greater efficiency and less toxic effect for common chemical disinfectants. Therefore, the aim of this study was to evaluate the antimicrobial effects of Matrica and Chlorhexidine compared to Sodium hypochlorite on Enterococcus faecalis and Candida albicans in the laboratory conditions.
In this in vitro study, Candida albicans and Enterococcus faecalis microorganisms were cultured with Kirby Bauer method on Mueller Hinton agar medium. Then paper disks impregnated with Matrica (pure and 50%), chlorhexidine (0.2% and 0.1%) and sodium hypochlorite 1% were placed on the medium. Forty-eight hours later, the zone of growth inhibition was measured in terms of millimeters. Data were analyzed by SPSS-18 software using ANOVA and TUKEY statistical tests.
According to the findings of this study, the highest mean diameter of inhibition zone of bacteria Enterococcus faecalis and Candida albicans, was for sodium hypochlorite 1% followed by chlorhexidine 0.2%, chlorhexidine 0.1%, pure Matrica and Matrica 50%, respectively (P Considering the results of this study, it seems that the antimicrobial effect of herbal composition of Matrica is not as efficient as sodium hypochlorite and chlorhexidine.

The viruses of hepatitis B and C are two of the most common blood-borne pathogenic microorganisms that are known as an occupational risk factor for health care workers. The aim of this study was to study the knowledge, attitude and practice of the students of Rafsanjan University of Medical Sciences regarding hepatitis B and C in the year 2012.
Material and In this cross-sectional study, 445 among 775 clinical students of Rafsanjan University of Medical Sciences were selected. Data was collected by a questionnaire which included two sections; the first section was the demographic data of the participants and the second one included 17 questions of Knowledge, 11 questions of attitude and 10 questions of practice. Validity and reliability of the questionnaire were confirmed by experienced specialists and calculating Cronbach's alpha coefficient (α=0.8). Data was analyzed using descriptive analysis, t-test, one-way ANOVA, by SPSS software version 17. P≤0.05 was considered as statistically significant difference.
The results showed that, from the aspect of knowledge, both male and female groups were the same. The knowledge of medical and dental students was in a higher rate compared to the paramedical students. The male group had better practice in comparison with females. The dental students had better practice and attitude compared to the other students. The results also revealed that the rate of knowledge and practice increases by an increase in the levels of education.
According to the results of the current study, we can conclude that the knowledge, practice and attitude of the students toward hepatitis B and C are average, therefore adequate policies to improve education in this case could be recommended.

The first maxillary and mandibular permanent molar teeth are the first teeth that erupt behind primary dentition. So they maybe decayed because of carelessness. Caries of these teeth can extend to the pulphorn and result pulp and periapical diseases. The purpose of this study is to assess the need for first molar root canal therapy in school children of 8 to11years old in Rafsanjan in 2013. In this descriptive study, 450 students of 8-11years (210 girls and 240 boys) were selected in Rafsanjan schools in 2013, using a random cluster sampling method. We examined their maxillary and mandibular first molars with a mirror and an explorer.We used SPSS version 17 and Chi-square and Mann-Whitney tests for statistical analysis. P< 0.05 was considered as significant. In 57 students (12.66%) there was an indication for endodontic treatment of the first molars. The need for endodontic therapy was significantly related to the subject's age (p=0<001), father's education level (p=0.046), mother's education level (p=0.005) and father's job (p=0.001). Age, gender, parent's eduction level and job are important and influencing factors in necessity of first molar root canal therapy in 8- to 11-year-old school children.

Good apical seal plays a critical role in the success of endodontic treatment and the smear layer reduces the efficacy of the apical seal. The aim of this study was to evaluate the effect of Nd:YAG laser irradiation on the apical seal of root canal-treated teeth using the fluid filtration technique. In this in vitro study, 44 human maxillary central incisors were selected. After preparation, the specimens were randomly assigned to 4 groups: group A, the control group (n=20); group B, the laser-treated group (n=20); group C, the positive control group (n=2); and group D, the negative control group (n=2). All the groups were prepared using the crown-down technique. Group B was irradiated with Nd:YAG laser before obturation. Groups A, B and D were obturated with gutta-percha and sealer and group C was obturated with gutta-percha and without sealer. The coronal end of the specimens were sealed with amalgam and then stored in an incubator for one week. Then, the outer surface of groups A, B and C, except for 2 mm in the apical area, and group D were entirely covered with two layers of nail polish and one layer of sticky wax. Apical microleakage was then evaluated using fluid filtration technique. Data were analyzed with SPSS 18, using Kolmogorov-Smirnov and independent t-test (α=0.05). The means of apical leakage in the laser and control groups were 4.35±2.88 and 5.34±3.13 µL/min/cm H2O, respectively, with no significant differences (p value = 0.305). Under the limitations of this study, use of Nd:YAG laser in root canal therapy had no significant effect on apical microleakage.

Fear and anxiety due to dental treatments have been identified as on of the important factors in delation and avoidance of dental care which is a major obstacle in diagnosis and treatment of dental peoblems on time. This study aimed to determine dental fear and anxiety prevalence in the students of Rafsanjan university of medical sciences، 2010-2011. This descriptive study was conducted on 400 students of Rafsanjan university of medical sciences. Needed information were gathered through demoraphic، DAS and DFS standard questionnaire and analyzed using SPSS-15 statistic software and Chi-square test. among 400 particapants،110 (%27. 5)، 67 (%16. 75)، 97 (%24. 25) and 126 (%31. 5) students were studying at medicine، nursing، midwifery and other courses، respectively. 218 (%54. 5) students were female. dental fear was reported by 333 (about %83) students and 161 (about %40) reported dental anxiety. Based on the majore، the maximum and minimum anxiety level dedicated to the medical students [18 (%42. 9) severe DAS] and dental students [4 (%9. 5) severe DAS]، respectively (P<0. 0001). About the fear of the treatment، paramedical students had the most fear level [87 (%37. 3) severe DFS] and dental students had the least fear [25 (%10. 7) severe DFS] (P<0. 0001). most students suffered from dental anxiety and fear، however the least score of DAS and DFS were observed among dental students.

A good apical seal plays a critical role in the success of endodontic treatment. The most common cause of treatment failure has been the lack of root apical seal. The aim of this study was to compare the apical seal of three root canal sealers including AH26، AH Plus and Tubliseal together and with positive and negative groups، using a dye penetration test. One hundred and ten humon upper central teeth were used in this study. Teeth were kept in 10% formalin solution and then were maintained for three days in 5. 25% NaOCl. The teeth were randomly divided into three experimental groups (N=30) and two negative and positive control groups. After debridement of the external surfaces the crowns were cut at the CEJ، and were instrumented by stepback technique and obturated using lateral condensation technique with gutta-percha and either AH26، AH Plus or Tubliseal. In positive control group، after preparation، the canals were filled with gutta-percha without sealer، and in negative control group، the canals were prepared but not filled. Two mm of coronal canals were filled with amalgam and negative control group were coated with two layers of nail polish and one layer of sticky wax، and next، were incubated for 72 hours after that، the surface of the other teeth except 2mm in apical area was coated with nail polish and wax. Finally then the teeth were centrifuged with India Ink and kept in ink for 72 hours. After longitudinally sectioning، the amount of dye penetration was measured under the stereomicroscope by three individuals who were blind to the groups. Data were analyzed by ANOVA and post hoc Tukey HSD test، through SPSS 15 software. Higher level of dye penetration was observed in group B (Tubliseal) which was significantly greater than the rate in groups A (AH26) and C (AHPlus)، while the difference observed between groups A and C was not statistically significant. The results of this study showed that although AHPlus is better than AH26، there was no statistically significant difference in apical seal of AH26 and AH Plus sealers: However، the leakage of them was significantly less than that of Tubliseal sealer.

Endodontic treatment causes local trauma and subsequent inflammation, making pain and discomfort common side effects of endodontic treatment. Since there is an important relationship between post- endodontic pain and preendodontic pain, use of non-steroidal anti-inflammatory drugs (NSAIDs) before root canal therapy can suppress the inflammatory process before it starts, and reduce the pain after root canal therapy. The aim of this study was to compare the efficacy of prophylactic Ibuprofen Sulindac (both are NSAIDs) and placebo in controlling pain after root canal therapy. In this triple-blind clinical trial study, 48 patients with vital, single rooted anterior teeth were selected. These teeth were divided into three groups. One capsule was given to every group as prophylaxis before the treatment, which according to its code, contained Ibuprofen, Sulindac, or placebo. The treatment was then performed by one person (a general practitioner) according to standard methods. The pain of each patient was recorded before treatment and at 6, 12, 24, 48, and 72 hours after the treatment using a VAS scale. The results were collected and comparison of the means of pain between the three groups was conducted statistically. A reduction in pain was seen in Sulindac and Ibuprofen group at 6,12,24,48, and 72 hours after treatment compared to before treatment and placebo group, but the difference was not statistically significant (P>0.05). Since no statistically significant difference was observed between the groups, prophylactic use of these drugs for reduction of post-endodontic pain is not suggested.

Applying the suitable mouthwash can kill bacteria or reduce the bacterial growth; in the same context, diluting mouthwashes can decrease their probable side effects. In this study, the maximum inhibitory concentrations of two common mouthwashes were evaluated. In this in vitro study, agar dilution and disk diffusion methods were used. Sixty-nine bacterial plates were cultured to evaluate the effects of thymol and chlorhexidine mouthwashes on Streptococcus mutans and Streptococcus sanguis. The results of agar dilution method were recorded as "growth' and "no growth", and the results of disk diffusion were recorded as means of growth inhibitory halos. Data was analyzed by Kruskal-Wallis test using SPSS software. (α = 0.05). Growth inhibitory halos for different concentrations of the two mouthwashes decreased with an increase in dilution rate. In agar dilution method, dilutions less than 80% of the initial concentration for thymol-based mouthwash and less than 70% for chlorhexidine could not inhibit bacterial growth. Growth inhibition halos with 100% thymol-based mouthwash (Orion®) were 10.15 ± 0.1 mm for Steptococcus mutans and 9.2 7 ± 0.16 mm for Streptococcus sanguis. Mean rank of the two mouthwashes was statistically significant for the two bacterial strains under study (p value < 0.001). Both mouthwashes were effective on the bacteria under study; however, this efficacy was higher for Streptococcus sanguis. Chlorhexidine mouthwash was more potent to inhibit bacterial growth than thymol-based mouthwash if diluted.

It is not possible to avoid the occurrence of emergency accidents in private dental offices. In order to manage the emergency accidents, scientific and practical knowledge is necessary. The present study aimed to assess the presence of both medicine and ancillary equipments in dentists’ emergency kit of private dental offices in four southeast cities in Iran. In this descriptive study‚ all dentists working in their private dental offices were invited to help with this survey in four southeast cities in Iran (2007-2008). Data collection method included interview with the dentists‚ observing emergency kit and filling in the checklist by trained experts. Data were analyzed using parametric (t-test) and non-parametric (chi-square & Fisher’s Exact) tests. Among the 126 dentists, 117 dentists accepted to help with the survey (Response rate=92.9%). Mean age of respondents was 36±7.6 years. Mean duration of respondents working in their private offices was 6.6±6.9 years. 53% of respondents had participated in emergency medicine courses and only 39.3% had the emergency medical kit in their private offices. Unfortunately‚ all of the kits were incomplete. Mean age of dentists shows that they would work in their private dental offices for a long time. On the other hand, our results showed that a majority of private dental offices in our study did not have emergency kits or existed emergency kits were incomplete. These results confirm the need for planning and managing emergency medicine courses both for dentists and students in dental schools.

Generally, a material with less toxicity and greater antimicrobial effect seems more agreeable to use. The aim of this study was in vitro comparison of the antimicrobial effects of Persica® and Chlorhexidine with Sodium hypochlorite on Enterococcus fecalis and Candida albicans. In this in vitro experimental study, 92 samples of study microorganisms were cultured on meuller hinton agar with Kirby bauer method. Paper discs were treated by Persica (pure and 50%), Chlorhexidine (0.1% and 0.2%) and Sodium hypochlorite 1% and placed on the culture media. After 48 hours incubation, Zones of microbial inhibition were measured in millimeters. Data were analyzed by Mann-Whitney and Kruskal-Wallis tests. Sodium hypochlorite was more effective in growth inhibition of the microorganisms than Persica and chlorhexidine significantly (P=0.000). In this study, the microorganisms were very sensitive to Sodium hypochlorite. Reducing the concentration of Chlorhexidine, lessened its effectiveness. There was not any sensitivity to Persica. Totally used concentrations had less effect than Sodium hypochlorite.