JOURNAL OF DENTISTRY (SHIRAZ UNIVERSITY OF MEDICAL SCIENCES)
Year:2009 | Volume:10 | Issue:2 (23)|Papers Count:12

Statement of Problem: Given the importance of bacteria in the development of periradicular lesions, the eradication of the root canal infection is paramount in endodontic treatment. The use of chemical irrigants during chemomechanical canal preparation is important for disinfection and cleaning of the canal system. Purpose: The aim of this in vitro study was the evaluation of effectiveness of 1% and 2% essential oil of Zataria multiflora as an irrigant in the elimination of Enterococcus faecalis from the infected root canals. Materials and Methods: The antibacterial effects of the irrigants in vitro were examined after 15 min, in freshly extracted human teeth with single roots, the canals of which were infected by E.faecalis. 1. 2ml of 2.5% NaOCl2. 2ml of 1% Zataria multiflora3. 2ml of 2% Zataria multiflora4. 2ml of sterile normal saline ( as control) Paper points used to sample bacteria from the root canals were transferred to tubes containing 5ml of brain heart infusion (BHI) broth. The tubes were incubated and the appearance of broth turbidity was indicative of bacteria remaining in the root canal. The data obtained were analyzed statistically for differences using the chi-squared test, comparing pairs of groups (p<0.05). Results: There was no statistically significant differences between the experimental groups (p >0.05). However, the experimental irrigants were significantly more effective than the saline solution (control group) in disinfesting the root canal.Conclusion: It seems that essential oil of Zataria multiflora was effective at killing E.faecalis. Application of this plant essential oil as root canal irrigants may be recommended following extensive ex vivo and in vivo experiments. The findings recommend further studies of the properties of Zataria multiflora such as toxicity, tissuesolving ability,  and biocompatibility to be applied for clinical use.

Statement of Problem: The use of calcium hydroxide powder in saline as an intracanal drug iscommon. Recently, the use of chlorhexidine solution for irrigation due to its antibacterial property has increased significantly. Purpose: The Purpose of this study was to compare the antimicrobial activity of calcium hydroxide combined with chlorhexidine gluconate against E-Feacalis and to compare the results with the calcium hydroxide mixed with saline and by chlorhexidine alone.Materials and Methods: In this study, 40 teeth with single canal were used. After removing the crown and preparation of the canal with step-back technique, the root canal was irrigated with EDTA solution to remove smear layer. Then, all the samples were sterilized in autoclave and the roots were infected with E faecalis and incubated. Subsequently, the roots were divided into 3 treatment groups. Group 1 was treated with calcium powder hydroxide in salin, group 2 with calcium hydroxide powder in chlorhexidine, and group 3 with chlorhexidine. All the samples were incubated for a period of one week at 37°C. Sampling was done by paper point. The microbiological samples were plated to count the colony-forming units and the level of CFU was assessed at the wavelength of 540nm by photometer. The mean number of colonies in all the three groups was assessed by variance analysis, and turbidity and transparency of the samples were assessed via chi-squares (x2) test.Results: The results showed that chlorhexidine gel was significantly more effective than calcium hydroxide with chlorhexidine, calcium hydroxide, and control saline solution (p=0.06).Conclusion: The results revealed that chlorhexidine gel has antibacterial effects against E-Feacalis. In fact, the study in the field showed that adding chlorhexidine to calcium hydroxide results in an increase in antibacterial effect of calcium hydroxide and reduces the antimicrobial effect of chlorhexidine.

Statement of problem: Retreatment procedures in endodontics require the complete removal of the original root filling materials. The most common materials that must be removed during retreatment are gutta-percha and sealers. Purpose: The aim of this in vitro-experimental study was to compare the amount of residual filling material after retreatment of the root canal walls which were obturated with gutta-percha or Resilon.Materials and Methods: Thirty extracted premolar single root human adult teeth were selected and prepared by race rotary files up to MAF#35. Then, they were divided into two groups of 15 (A and B). Group A was obturated with gutta-percha and AH26 sealer and group B with Resilon system by lateral condensation technique. After 4 weeks all the canals were retreated by Race rotary files and the use of chloroform and master apical file increased to #40 file. Then, the teeth were split longitudinally and the remaining materials on the surface of the canals were visualized with streomicroscope with 20 magnification and digital photographs captured. The amount of residual materials and time of retreatment were analyzed with Mann-Whitney and Freidman tests.Results: The highest residual material value was in Resilon group and the difference between the twogroups was significant (p <0.001). The time required for retreatment was not significant between the two groups (p =0.381).Conclusion: Orthograde retreatment of Resilon was less efficient than gutta- percha with more residual materials on the surfaces of the root canals that were filled with Resilon.

Statement of Problems: Evaluating cytokeratin contents of odontogenic cysts and tumors can be one of the important aspects in comparative study of these lesions.Purpose: The aim of this study was to evaluate expression of CK13 and CK18 in odontogenic cysts and ameloblastomas.Materials and Methods: In this study, radicular cysts (20 cases), dentigerous cysts (20 cases), OKC (20 cases), unicystic ameloblastoma (20 cases) and solid ameloblastoma (20 cases) were evaluated. Then, 3-4 m msections were prepared and stained with immuhistochemical procedure (avidin- biotin method. The obtained data by microscopic consideration was analyzed with statistical tests such as: Chi-square, Mann-Whitney, Wilcoxon (p <0.05).Results: All of the odontogenic cysts and cystic parts of unicystic ameloblastoma expressed CK13 in the upper layers (middle and superficial) more than the deeper ones (basal and parabasal). In ameloblastomas, CK13 expression in stellate reticulum and acanthomatose component was more than preameloblasts. Expression of CK18 in the upper layers (middle and superficial) was more than deeper layers (basal and parabasal) in radicular and dentigerous cysts. Results of immunoreactivity with CK18 in OKC were negative in 100% of cases. In addition, ameloblastomas (unicystic and solid) did have not significant differences in expression of CK13 and CK18. Conclusion: CK13 did not show any differences between these lesions but significant difference in CK18 expression at all 4 layers of the epithelium in odontogenic cysts and ameloblastomas may indicate the different nature of these lesions and probably confirms this suggestion that unicystic ameloblastoma is initiated as a neoplasm essentially, no from neoplastic change of an odontogenic cyst, in particular dentigerous cyst. The same CK13 and CK18 expression pattern in unicystic and solid ameloblastomas reveals the same biomolecular nature despite different gross and clinical features.

Statement of Problem: Odontogenic cysts (OC) are relatively common lesions that can behave aggressively and attain large sizes.Purpose: This study has been conducted to evaluate the prevalence of OCs and their clinical features in three centers in Shiraz which receive most of the oral biopsy specimen in Fars province.Materials and Methods: In this retrospective study, the histopathologic reports from the archives of the department of pathology of Shiraz Dental School, Khalili and Namazi Hospitals pertaining to a 10 year interval (1375-1385) were reviewed. All odontogenic cysts were listed and their clinical features including sex, age and location were registered and classified according to the latest classification of World Health Organization (WHO) in OCs the results were than descriptively analyzed.Results: Among a total of 110,000 files, 179 were retrieved as OCs after excluding 45 cases of OCs that were non-specifically reported as infected odontogenic cyst. The remainder consisted of 44 cases of radicular syst (32.83%), 42 cases of Dentigerous cyst (31.34%) and 35 cases of Odontogenic keratocyst (26.12%), respectively. OCs was more prevalent in male gender, the posterior mandible and 2nd decade of life.Conclusion: The most frequent OCs, in the studying population were radicular cyst and dentigerous cyst, respectively.

Statement of Problem: Many clinical studies have reported on the success of sealants with respect to caries reduction. Saliva contamination during the procedure is the main reason in sealant's failure.Aim: The aim of this study is to evaluate the effect of two types of adhesive (Excite, Prompt-L-Pop) on reducing sealant microleakage in saliva-contaminated enamel.Materials and Methods: In this experimental study, 40 intact premolar teeth were chosen and divided into four groups. Group 1: the teeth were etched and sealed with sealant without any contamination. Groups 2 and 3: the teeth were etched and exposed to saliva for 10 seconds, and air-dried. Consequently, a bonding agent (Excite, Prompt-LPop) was applied prior to the sealant application and curing. Group 4: After being etched and contaminated, the teeth were sealed without any bonding agent. After some processes the teeth were bucolingualy sectioned and the samples were evaluated under stereomicroscope. The findings were statistically analyzed, using Kruskal-Wallis and Mann-Whitney tests.Results: The results showed that the amount of micoleakage in the saliva contaminated fissure sealant without bonding agent group had a significant difference with the sealant without saliva contamination group (p<0.05). Besides, there was no significant difference in the amount of microleakage between Excite, Prompt-L- op groups and the non– contaminated fissure sealant group.Conclusion: Exposing the enamel to the saliva after acid etching and prior to sealant application would increase the microleakage significantly. Using Excite and Prompt-L-Pop, the dentin adhesives, after salivary contamination would decrease the microleakage to the extent of non-salivary contaminated fissure sealant group.

Statement of Problem: Iran has one of the highest numbers of young people in the world; therefore, epidemiologic studies of dento-skeletal malformations in adolescents and young adults are important from population health viewpoints.Purpose: The purpose of the study was to assess the needs for orthodontic treatment according to Index of Orthodontic Treatment Needs (IOTN) in 14-18 year old students in the city of Shiraz Materials and Methods: 1818 students were selected from four districts of education in Shiraz using random cluster sampling. The dental health (DHC) and aesthetic (AC) components of the IOTN were used as an assessment measure of for orthodontic treatment needs. Also, demographic characteristics of the participants were recorded using a questionnaire. The data were analyzed using the student and Chi-squared tests. Results: 60% of the students had no need for orthodontic treatment, 28.4% were in borderline category, and 11.7% showed definite needs for treatment. Also, there was a statistically significant association between malocclusion severity and sex or father’s job or education.Conclusion: 14-18 year old students in Shiraz had better dental appearances and did need less orthodontic treatment than in other populations.

Statement of problem: The yearly incidences of AIDS continue to grow in Iran. The only way to preclude the outbreak of AIDS virus is promoting the society’s awareness about the disease. However, to implement an effective health educational program, the first step is to have an appropriate correct understanding of the society’s knowledge about this disease.Purpose: The aim of this study was investigation of the knowledge and attitudes of patients in clinics of Kerman dental school about AIDS in 2006.Materials and Methods: In this study, 328 patients (aged 15 years or over) referred to oral medicine department were selected. To gather the data, a questionnaire including demographic data and questions on knowledge and attitude toward AIDS was prepared. SPSS (13.5) program, Chi-Square, t-test and variance analyze were used for data analysis.Results: From 328 patients, 36.00% were male and 64.00% were female (mean ages of cases was 31.74±12.212 years). The mean knowledge score was 69.31%. Most of the cases (67.7%) were informed of HIV/AIDS by TV programs. The level of knowledge of women about AIDS was significantly higher than men (p =0.031). In addition, there was a significant relationship between the level of knowledge and education (p =0.0001). 86.9% were concerned about AIDS transmission in the dental offices. 48.5% of the cases asked for diagnostic trials for AIDS before any dental treatment for all of the patients, and 48.2% asked for isolation of patients who carry the HIV/AIDS virus.Conclusion: The results stress the importance of providing information about AIDS by media more frequently and with higher quality. Another important factor is having good infection control standards in dental practices.

Statement of problem: Zinc phosphate and polycarboxilate cement have wide application in operative, pedodontics dentistry and fixed prosthodontics. The Ariadent zinc phosphate and polycarboxilate cements are manufactured in Iran. One of the important and necessary properties of each cement to be used in oral cavity is its low solubility. Purpose: The purpose of the present study was to determine and compare the solubility of Harvared zinc phosphate and polycarboxilate cement with Ariadent.Materials and Methods: In this experimental study that was based on specification No 2725 and 2726 of Iranian standard, ten discs shaped samples with 1±0.03 mm width and 10±0.3 mm diameter was constructed for each cement. Zinc phosphate solubility with spectrophotometry and polycarboxilate solubility with conductivity evaluation was measured. The data were analyzed with T test. Statistical analysis was significant (p<0.05). Results: The mean value of solubility for Harvard and Ariadent zinc phosphate cement was in order 1.23±0.24 and 0.86±0.15 mgr P2O5 per gr. There was statistically significant difference between the two above cements (p =0.001). The mean value of solubility for Harvard and Ariadent polycarboxilate cement was in order 39.27±4.40 and 37.85±3.05 simence on the meter per kg. There was no statistically significant difference between the two above cements (p =0.4).Conclusion: In accordance to determined values from Iranian standard No 2725 and 2726, the mean value of solubility of 4 experimental cements in this study was within standard limits.

Statement of problem: Recurrent aphthous stomatitis is one of the most common ulcerative lesions of the oral cavity, but up to now no cure has been recognized for it. In some studies low level lasers had good efficacy in reducing pain intensity and healing time in recurrent aphthous stomatitis but in some other studies the results were controversial.Purpose: The aim of this study was to evaluate the efficiency of LLLT in treatment of RAS as compared with the placebo effect.Materials and Methods: In this double blind clinical trial, 24 patients with minor RAS who didn't use any drugs for it or didn't have any other related systemic disease to RAS were selected and randomly divided into 2 groups of 12 cases and 12 controls. In the case group, laser was irradiated but for the control group, the procedure was similar but laser wasn't irradiated to lesions. In this research, diode laser (660 nm, 3 J/cm2, continuous) was applied. The pain intensity (VAS), the time of pain relief and healing time were evaluated. The data were analyzed by T-test, pair-T-test and covariance.Results: This study showed that healing time was 5±1.41 days in the laser group and 8.25±0.96 days in the placebo group. Difference between the two groups was significant statistically (p<0.001). According to covariance analysis, the pain difference at the end between the two groups by considering the pain difference before treatment was significant (p =0.009).Conclusion: According to the results of this study, low level laser can decrease the healing time, pain intensity and the time of pain relief in patients with aphtae.

Statement of Problems: Pain is the major reason for referring patients to dental clinics. Inappropriate use of analgesics can result in noticeable systemic side effects. Prescribing the best drug according to the severity, nature and quality of the pain can result in reduction of anxiety and stress which are aggravated with intensification of pain. Purpose: The aim of this study was to investigate the analgesics prescription by dentists participating in the 9th Congress of Iranian Association of Endodontists in Esfahan/2006.Materials and Methods: A questionnaire for this cross-sectional study was designed for evaluating the patterns of analgesic prescription. It included some demographic information and drug selection to control severe, moderate and mild toothache. 113 collected questionnaires entered the study. Chi- square test was used for data analysis. Results: Based on this study, a high percentage of responders selected Ibuprofen, acetaminophen with codeine for pain control in severe, moderate and mild toothache (96%, 81% respectively). Most responders prescribed ibuprofen (400mg) before endodontic treatment.Conclusion: The results of the present study demonstrated discrepancy in the analgesics selection among participants.