Journal of Islamic Dental Association of IRAN
Volume:19 Issue: 4, 2008

It has been reported that, administration of excessive vitamin A can lead to profound effects on bone. This vitamin can induce bone degradation by stimulating the formation of mature osteoclasts from precursors. This study was designed to determine the effect of vitamin A on orthodontic tooth movement (OTM) using animal model. A total of 80 male Wister rats were included in this clinical trial. They were divided into eight equal groups. Orthodontic appliances were applied in all the eight groups to deliver an initial force of 60gr for 14 days on the first molar tooth. Six different doses of vitamin A were prepared. In addition to study groups, two control groups were considered as well. One control groups received daily intraperitoneal injections of olive oil and the other did not. Five rats were considered as normal base which received neither appliance nor injection and they were used for histological comparison with all groups. Study groups received 250, 500, 750, 1000, 1750, 2500 IU/Kg doses of vitamin A intraperitoneally each day. OTM was measured at the start and at the end of the study. Blood samples were taken from the heart, and the level of serum alkaline phosphatase was evaluated. After sacrificing the animals, cross-sections of maxilla were prepared by H&E and histological assessments were performed. The descriptive data was analyzed with SPSS version 11 and results were presented by mean and standard deviations. Group differences were analyzed by using One-way ANOVA, followed by Tukey, Kruskal-Wallis and Chi-Square tests. From the eight groups studied the highest amount of OTM was observed in the 2500 IU/Kg group and the least OTM was demonstrated in the 250 IU/Kg study group. Histological assessments showed no difference between vitamin A-treated and control groups. No difference was demonstrated between the groups when comparing the number of osteoclasts, cementoclasts, PDL width, root resorption, and serum alkaline phosphatase (P>0.05). However significant difference was observed between normal base group and the other eight study groups. Based on the results of this study, despite reported effect of vitamin A on bone tissue, it did not accelerate alveolar bone remodeling and therefore did not change the process of orthodontic tooth movement.

Usually, traumatic dental injuries are considered a bad experience to children. It is important to treat these conditions as soon as possible. The aim of the present study was to evaluate the knowledge of general dentists practicing in Tehran regarding the management of such injuries. This cross sectional survey was carried out in Tehran. A total of 165 general private dentists were included in this study. A questionnaire was used to collect information from the study participants. The SPSS statistical software package (Version 11.5) and Mann–Whitney, Kruskal–Wallis, Independent sample t-test and Pearson correlation coefficient were used for statistical analyses. Knowledge of dentists regarding traumatic injuries to children’s teeth was %64 and the amount of their Knowledge had inverse relation with their age and direct relationship with the time of graduation from dental school. Based on the results of this study, general dentists practicing in Tehran have relatively adequate knowledge of dental trauma. However, it is necessity to further expand their knowledge through continuing medical educations.

Pemphigus vulgaris is a chronic vesicular and autoimmune disease that involves the skin and mucosal membranes. The prevalence is low and drugs used for treating pemphigus have a lot of side effects. It has been suggested that homeopathy may be helpful in treating pemphigus conditions. The aim of this study was to evaluate the role of homeopathy in treatment of pemphigus vulgaris patients. Report of Cases: A total of 12 new patients were identified over 1.5 year period. Those who did not used any drug for treatment of their pemphigus. Seven patients volunteered to be treated by homeopathy. Homeopathy treatment was applied for four weeks during the waiting period until biopsy confirmation report was received. No drug was used over this period in order to evaluate the efficacy of homeopathy alone. By the end of homeopathy treatment, patients were evaluated regarding the number of lesions, amount of pain and their wellness. According to the findings, two patients had prominent remission and six of them reported feeling better and had less pain. It seems that homeopathy does not have the expected efficacy of conventional therapy in controlling pemphigus conditions, but it may be used together with conventional treatment in order to reduce pain, dosage of corticosteroid medication used and also facilitates patient's recovery. In conclusion, further studies are required in order to determine the value of homeopathy more accurately when treating pemphigus conditions.

Different materials are used in orthodontic treatments. These materials are subjected to damp oral environment which can modify their properties. The purpose of this study was to evaluate the in-vivo biocompatibility of eight orthodontic materials, which were implanted in rat connective tissues. Through an interventional experimental study, the biocompatibility of eight clinically used materials were evaluated. These materials were composed of two coil springs (S.L.S and NiTi), two glass ionomer cements (Bandtate and Ariadent), two O-ring (American ortho and Pooyan tebbe nour) as well as two orthodontic acrylic resins (Acropars and Bayer). Ninety-six white female rats were included in the study. Five sites were marked on the dorsal subdermal connective tissue of each rat, and then two pieces of each material measured at one centimeter long were implanted in the right side and two pieces of another material on the left. Also a similar incision was made at the two other marked sites, and then sutured, without inserting any material. Biopsies were taken from the specified sites, 15, 30 and 60 days following implantation. Tissue reactions were reported after microscopic evaluation, using the inflammation assessment chart. Non-parametric tests such as Kruskal-Wallis and Mann-Whitney tests were used for data analysis. This study demonstrated biocompatibility of acrylic resins and O-rings in the 15- and 30-day experiments. In the glass ionomer cement biopsies significant inflammatory reaction was detected In the 60-day experiment. Significant biocompatibility difference was observed between the coil springs groups (S.L.S-NiTi) and controls In the 30 and 60-day experiments. This study suggests that coil springs and glass ionomer cements can be considered as cytotoxic materials. Although, further studies are recommended in order to support these findings.

There are a few conditions that prove a sealer to be suitable for use in practice. One of the important factors in a good sealer is its biocompatibility. The purpose of this in-vivo study was to compare the biocompatibility of two types of endodontic sealers; AH26 and Apexit by using animal model. A total of eleven white rats were included in this interventional in-vivo study. After sedation of rats, two sealers (AH26 and Apexit) were implanted in the subcutaneous tissue of each rat. AH26 was implanted in two sites of subcutaneous tissue in the left side and Apexit was implanted in two sites in the right side and the control site was designated in between them. In control group, the incisions were made similar to AH26 and Apexit groups and sutured without insertion of any material. Biopsies were taken from five rats after three days and from the other six rats after thirty days. Histological specimens were studied by pathologist and findings were reported. Data was analyzed using appropriate statistical procedures as well as Mann–Whitney and Kruskal-Wallis tests in order to report the significance level Although Apexit caused more inflammation compared to AH26, after 3 and 30 days, but such difference was not statistically significant (P>0.05). However, both sealers initiated mild to moderate inflammation when judged against control group and the difference was statistically significant (P<0.05). Even though AH26 and Apexit cause inflammation in subcutaneous tissues of rats but they have moderate biocompatibility as the inflammation was graded two in this study according to the pathologic report.

Hepatitis B virus (HBV) is one of the main causes of chronic liver disease and hepatocellular carcinoma. Dentists, surgeons, and dialysis staff, are considered to be at higher risk of HBV compared to other health care providers. The aim of this study was to determine the correlation between anti-HBs level with education status and duration of dental experience among dentists practicing in Qazvin city, Iran. The participants of this analytical-descriptive survey were consisted of all dentists practicing in Qazvin. A questionnaire was used to collection demographic and clinical information. This step was followed by the collection of blood samples. ELISA technique was used for laboratory assessment of serum specimens for HBsAg and anti-HBs antibody titer. SPSS software and Chi-square test were used for data analysis. Out of 77 dentists who completed the questionnaire, 74 (93.7%), including 49 general practitioners (63.6%) and 24 specialists (36.4%) supplied their blood samples. All blood samples were HBsAg negative. A total of 40 general practitioners (81.6%) and 24 specialists (85.7%) had proper vaccination (dosage). Among all, 34 general practitioners (69.4%) and 12 specialists (24.9%) reported exposure to patients with hepatitis. The antibody level was less than 10 mIU/ml in 8 general practitioners (10.8 %), 10-100 mIU/ml in 12 dentists (16.2%), 100-500 mIU/ml in 23 (31.1%) others, and it was more than 500 mIU/ml in 31 dentists. This level was positive (10-500 mIU/ml) in 2 general practitioners (2.7%) that did not have prior vaccination history. There was a significant correlation between antibody level and vaccine dosage (P= 0.04), as well as the education status (general and specialist) (P=0.03). There was no significant correlation between antibody level and duration of dental practice. This study showed significant correlation between anti-HBs antibody levels with education status of dentists in Qazvin city. However, we were not able to detect a significant correlation between antibody level and duration of dental practice in this population.

The number of complaints filed by patients at the Iranian Medical Council is rising in recent years. Some of the complaints are related to orthodontics malpractice cases. The aim of this study was to investigate the frequency of orthodontics malpractice complaints filed against either specialists or general dental practitioners according to the final decree registered at the Iranian Medical Council. This descriptive study was designed to examine the relevant documents filed since 1372 (1994), which received rulings by the Iranian Medical Council. Of the 54 orthodontics cases, 31 were filed against general practitioners, 16 against orthodontists, 3 against pediatricians and 4 against so-called denturists. A total of 25 cases were acquitted of all charges, 3 cases were punished verbally, 33 cases received written notice and 4 cases of dentuirists were referred to court. Among all, 27 malpractice cases were against removable and 26 involving fixed orthodontic treatments. Twelve convicted individuals were also charged with lack of professional care, 14 with lack of expertise, and 2 for negligence. This study shows a considerable rise in convicted malpractice cases filed against general dental practitioners (88%), according to registered cases at the Iranian Medical Council over the past ten years. For prevention and control of such events, this result suggests that more education and closer supervision as well as enforcement of regulations are required by authorities.

The local made eugenol-free temporary cement (P-cem) has been used by considerable number of Iranian dentists. The purpose of this study was to evaluate the physical properties of this cement and compare it with Temp Bond of Switzerland using ISO 3107 criteria. In this laboratory investigation we used 6 samples of each cement type, in order to test and determine the average setting time, compressive strength, film thickness, as well as solubility and disintegration rate according to ISO 3107 standards. After conducting data analysis, Student T-test was used for detection of significance level. The average setting time was 4.57 and 4.03 for P-cem and Temp Bond respectively. The average compressive strength for P-cem was 5.7 Mpa and 9.6 Mpa for Temp Bond. The average film thickness for P-cem was 20.16 μm and 5.83 μm for Temp Bond. The 24-hour solubility and disintegration rate for P-cem was %1.03 and %0.9 for Temp Bond. Analysis of data showed significant statistical difference between the two cements with regards to setting time, compressive strength and film thickness (P<0.001). However, there was no significant difference between the two cements in relation to solubility and disintegration rate, although the values for both cements were within the standard range according to specifications of ISO 3107. Based on the findings of this study, both cements can provide valuable clinical applications, although biocompatibility test for P-cem is highly recommendable.

Recent studies have reported the increase in bonding stability when collagen was removed from the dentin surfaces. This study was designed to investigate the effect of collagen removal on the shear bond strength of three single bond dentin bonding systems with structural differences. This laboratory experiment was performed on 100 intact bovine incisors. Smooth surfaces of dentin on the buccal aspects of teeth were prepared. The samples were then classified, according to dentin conditioning and bonding types, into 4 main groups A) The use of 3 adhesive systems, P&B NT, SB, and PLP, with no dentin treatment by sodium hypochlorite solution (control group). B) The use of adhesive system P&B NT with dentine treatment by sodium hypochlorite solution for 1 min, before, after and without etching. C) The use of adhesive system SB with dentine treatment by sodium hypochlorite solution for 1 min before, after and without etching. D) The use of adhesive system PLP with dentine treatment by sodium hypochlorite solution for 1 min before bonding system. A cylinder of Z100 (3M) dental composite with a 2-mm diameter and 3-mm height was placed on the adhesive covered dentin surface of all groups and light-cured (900 mW/cm2, for 40 sec).The specimens were kept in distilled water at room temperature for one week and then thermo cycled for 500 times (5-556). Shear bond strength of specimens was measured using a Zwick testing machine with cross-head speed of 0.5 mm/min and chisel from shearing blade. Data were analyzed by Two Way ANOVA, Tukey HSD and Dunnet T3 tests with P-value < 0.05 as the limit of significance. 1) Bonding type, dentin conditioning and their combined effects had statistically significant effects on the shear bond strength (P<0.05). 2) The mean shear bond strength values were not the same in the PLP and P&B NT groups and were found to be higher in the PLP group (17.41±2.96mpa-12.77±1.51mpa). 3) In the P&B NT group, there were statistically significant differences in the mean shear bond strength among different dentin conditioning methods in all binary comparisons (except between control-H1). 4) In the SB group, there were statistically significant differences in the mean comparisons (except between control-H1 and H1-H2). 5) In the PLP group, statistically significant differences in the control-H1 groups in the mean shear bond strength values were found. Collagen removal from dentin surface caused a significant decrease in shear bond strength of alcohol, water and acetone-based bonding systems except when hypochlorite was used before etching in the acetone-based bonding system.

Weaker immune system in smokers reduces the favorable response of these patients to both surgical and non-surgical periodontal treatments in comparison with non smokers and ex-smokers. The aim of the present study was to compare the healing of periodontal tissues following phase1 therapy alone, or along with taking Azithromycin or Doxycycline in smokers with chronic periodontitis. In this investigation a total of 45 male smokers with chronic periodontitis were randomly assigned into 3 groups, each containing 15 patients. All patients were initially examined by measuring the periodontal indices, such as Bleeding On Probing (BOP), Clinical Attachment Level (CAL), and Probing Depth (PD). The control, group received phase1 therapy only. While the second and third groups received Doxycycline and Azithromycin respectively along with phase1 therapy. The periodontal indices were measured and recorded again after six months. The results showed that, there was a significant difference between all recorded parameters before and after the treatment (P<0.05). However, there was no statistically significant difference between Doxycycline and Azithromycin groups regarding PD index (P>0.05), but groups receiving antibiotics showed statistically significant reduction in PD compared to control group (P<0.05). The best result for CAL was obtained in Azithromycin group when compared with Doxycycline and control groups. Also, a statistically significant difference was detected between the two antibiotic groups (P<0.05). Furthermore, Doxycycline group showed a statistically significant reduction in CAL in comparison with the control group (P<0.05). Regarding BOP index no statistical significant difference was seen between the results of the 3 groups under investigation (P>0.05). Azithromycin and Doxycycline consumption along with phase 1 therapy may improve the clinical periodontal indices in comparisons with phase1 therapy alone.

Radiography is still the common method of measuring working length in root canal therapy. While, gag reflex, pregnancy or superimposition of anatomical structures on root canal may be considered as some of the limitations to this procedure. Therefore, application of any accessory measurement device may be useful. The aim of this investigation was to assess the ability of two apex locator systems (Ipex and Raypex5) in measuring root canal length accurately. A total of 160 extracted human teeth were used in this laboratory investigation. The teeth were divided into 3 groups of single-canal, two-canal and three-canal teeth. The access cavities were then prepared and the actual length of each canal was measured by inserting an appropriate file into the canal until the tip of the file was seen at the apical foramen. The Donnelly test medium was prepared and each tooth was placed in the medium up to the CEJ. The length of each tooth was measured again and recorded using Ipex and Raypex5 systems. The data were statistically analyzed using Liner-Regression, McNemar and t-tests. The accuracy of Raypex5 showed to be 83.1% (95% CI: 77.3-89). Likewise the accuracy of Ipex was 78.8% (95% CI: 72.3-85.2). Both measurements were with in the limits of ±0.5mm from apical foramen. Mc Nemar test showed no significant difference between the two groups (P=0.337). Based on the results of this study, it can be concluded that manufacturer's data are not always reliable. However, these systems can be used as accessories in addition to radiography for accurate working length measurements.

Cleaning and shaping has been recognized as one of the most important steps of root canal treatment. Various Ni-Ti rotary systems have been introduced for reduction of complications and facilitating the root canal shaping process. The purpose of this study was to determine the amount of transportation by using the three rotary systems, Profile, Flex master and Race. This ex-vivo randomized controlled trial was carried out on mesial mandibular root canals (type3 Weine) with mild curvature (15-35o). The roots were randomly divided into three groups of 20 canals each. The roots were sectioned horizontally at 3mm, 6mm from the apex and then, reassembled before instrumentation according to the manufacture's guidelines. Photographs were taken from the cross sections before and after instrumentation. Image analyses were performed by Photoshop software, version 8. The ability to preserve canal shape centrally as well as the direction of transportation was determined next. Data was analyzed by ANOVA and Tukey tests. The difference was significant in mid apical parts when comparing the three groups. Most transportation was in the furcation area. Race had the most and profiles showed the least transportation in both parts of the roots (P=0.001). The profile system was found to be the best for preserving the centering position of the root canal among the three rotary systems.