JOURNAL OF ISLAMIC DENTAL ASSOCIATION OF IRAN (MAJALLAH-I-DANDANPIZISHKI)
Year:2009 | Volume:20 | Issue:4 (69)|Papers Count:14

Background & Aim: Missing and supernumerary teeth are considered as dental developmental anomalies. These anomalies may lead to problems and complications such as dental asymmetry, poor esthetics, midline shift, dental crowding, malocclusions, caries, diastema, ectopic eruption, impactions, delayed eruption, external root resorption as well as loss of adjacent tooth’s vitality in some cases. The aim of this study was to investigate the prevalence of missing and supernumerary teeth in 3 to 5 years old kindergarten children of Tehran in 2005. Materials & Methods: This cross-sectional study was conducted by oral examination of 1000 children. Kindergartens were randomly selected in three major areas of Tehran province, namely Rey, Tehran-city and Shemiranat regions. Oral examination was carried out by counting the teeth under adequate lighting. Results: The prevalence of supernumerary and missing teeth in this study was 0.3% and all the anomalies were observed in boys. All cases of supernumerary teeth were in maxilla. From the three cases with missing teeth, two cases were in the maxilla (83%) and one case in the mandible. The anomalies observed in two samples occurred unilaterally in the lateral incisors (67%). Conclusion: Since missing and supernumerary primary teeth may lead to problems in the permanent dentition, early diagnosis and continuous monitoring of successors seem to be necessary to avoid further problems and therefore complicated treatments.

Background & Aim: Fractured crown is one of the most prevalent dental problems. Dental researchers and clinicians are trying to find the most effective reattachment technique in order to provide adequate resistance as close to intact human tooth as possible. The purpose of this study was to investigate the effects of using porcelain, composite and metal laminates on fracture resistance of the re-attached coronal fragments in human anterior teeth. Materials & Methods: This in-vivo study was conducted using forty recently extracted human lower incisors. Samples were randomly assigned into four groups. Ten teeth with no prior preparations were selected as the control group. The rest of teeth were sectioned mesiodistally, four mm under and parallel to the incisal edge. These specimens were randomly assigned to three groups. Re-attachment was performed using single bond and flowable composite in all test groups according to manufacturer’s instructions. In porcelain laminate (PL) group, veneer preparations were made for buccal surface (window preparation). Composite and metal laminate preparations were made in lingual surfaces of the teeth in composite laminate (CL) and metal laminate (ML) groups. After impression taking and laboratory process, all laminates were cemented using resin cement. All teeth were mounted in self cured acrylic blocks and kept in saline solution. Using a testing machine, fracture procedures were performed in a cross-head speed of 0.5 mm/minute. The tooth inclination for testing were set at 135o angle before the loading blade and kept it in this position until fracture occurred. Differences between four groups were determined using one way analysis of variance (ANOVA) at 0.05 significance level. Results: The mean fracture resistant in control, CL, PL and ML groups were 438.85 (±147.14), 420.05 (±109.59), 364.92 (±230.02) and 345.01 (±148.87) respectively. This analysis showed that, group differences were not statistically significant (P>0.05). Conclusion: Although composite laminate (CL) showed highest fracture resistance after the control group, but all the three techniques can be applied depending on the teeth and patient’s preferences.

Background and Aim: Dimensional stability of die plays very important role in fixed prosthodontic treatments. Different impression taking techniques may be the main source of die dimensional changes. However, in this regards, contradictory results have been reported in the literature. This study was designed to assess the dimensional accuracy of master casts prepared by means of three impression techniques using Speedex silicone impression material. Materials and Methods: This quasi-experimental study was carried out using laboratory stainless steel master models that contained three complete crown abutment preparations. The one-step, two-step with and without relief methods were the three putty-wash impression techniques used in this investigation. Fifteen impressions were taken for each technique and velmix casting material was used to prepare stone models. Profile Projector and micrometer were used to measure the final die’s height, diameter and different dimensions in order to compare them with laboratory model. ANOVA and paired samples t-test were used for data analyses. Results: The two step technique with spacer was the most accurate method with zero LC distance (distance between left and middle abutment). However, in the other two techniques, the mean difference was 0.22 (±0.01), (P<0.05). Regarding the distances between abutments, there was no significant difference when comparing one-stage and two-stage technique without spacer. Although, the height of abutment was more accurate in two-stage technique without spacer than one-stage. Conclusion: The two-step technique with spacer was the most accurate technique when using Speedex impression material.

Background & Aim: Traditional Beliefs as part of people's culture can influence the general wellbeing of communities. In order to promote healthy behaviors, it is important to be aware of people’s traditional background. This study was performed to identify beliefs, traditions and practices of mothers and teachers related to oral and dental health of children in the rural Qazvin areas. Materials & Methods: A qualitative study (ethnographic) was conducted in three villages of Qazvin province. Data was collected through interviews, observations, and focus group discussions. Data was coded and classified according to main study findings. Results: Information was classified into 6 categories: tooth eruption and exfoliation, diet and oral health, oral hygiene, dental caries, oral and gum diseases as well as dental trauma. Beliefs such as consuming a great amount of milk can be useful while others like putting un-cooked meat on top of tooth for relief of toothache can be harmful. Beliefs like rubbing onion on the gum during tooth eruption may have unknown or less important outcomes. Conclusion: The identified beliefs, traditions and practices were classified as useful, harmful & unknown effects. It was suggested to organize appropriate training classes for mothers and teachers in order to update their knowledge and improve their behavior regarding the proper oral health care of children based on the findings of this study.

Background & Aim: Dental handpieces are the most commonly used instruments in dentistry and their cross contamination is very high due to their direct contact with blood and saliva. The purpose of this study was to evaluate the antiviral effects of formalin tablets and autoclave on internal lumens of dental handpieces. Materials & Methods: This experimental study was designed in order to evaluate the effect of different materials and methods of sterilization and disinfection on virus elimination from internal spaces and interior chambers of dental turbines. Four study groups were composed of: 1) Vacuum autoclave, 2) Non vacuum autoclave, 3) Ten Para Formaldehyde tablets, and 4) Twenty Para Formaldehyde tablets. Nine turbines were tested in each group after preliminary washing, drying and autoclaving. The internal tubes and spaces were then contaminated with Polio and Herpes Simplex virus type I. Antiviral agents and devices were used according to the manufacturers’ instructions. Two cell culture samples were obtained from each handpiece, after washing them with sterile distilled water and MEM (Minimum Essential Medium). In each group one handpiece was designated as control. The culture results were recorded after one week. Results: Autoclaving was perfectly effective on both Polio and Herpes Simplex virus type I in all groups (vacuumed, non-vacuumed, with or without lubricant). Formalin tablets were 100% effective only on polio virus, and in the 20 tablet group turbines without lubricant. These tablets killed the Herpes Simplex virus in all groups. Conclusion: According to the results of this study, autoclaving is the best method of virus elimination in dental handpiece.

Background & Aim: Odontogenic keratocyst is a developmental odontogenic cyst. However, inflammation has been reported in the connective tissue layer of this cyst. On the other hand, Ki67 is a proliferation marker while, BCL-2 protein is an anti-apoptotic marker. The aim of this study was to evaluate the effect of inflammation on expression of ki67 and BCL-2 in odontogenic keratocyst. Materials & Methods: This retrospective descriptive analytic study was conducted with 20 cases of OKC. Specimens were divided into two groups of inflamed (n=10) and none-inflamed OKC. Two sections of 3µm, and 5µm were dissected from each specimen. This step was followed by Hematoxylin and Eosin staining first and then immunohistochemistry staining was performed using monoclonal antibody for Ki67 and BCL-2. Number of nucleus and cytoplasm of immunostained epithelial cells with Ki67 and BCL-2 in 1000 serial epithelial cells were considered as the labeling index (LI). Inflammatory infiltration density was recorded for each HPF by looking at the depth of adjacent basement membrane. The average inflammatory score and average labeling index were calculated for further comparison. Data was evaluated using Roc curve and student T-test analysis. Results: The mean Ki67 labeling index in all linings of inflamed and non-inflamed OKC was (19.8±0.88%), (17.9±1.03%) respectively. The mean BCL-2 labeling index in all linings of inflamed and non-inflamed OKC was (36.06±1.09%), (37.2±0.75%) respectively. The Ki67 and BCL-2 labeling index demonstrated significant differences between inflamed and non-inflamed OKC (P<0.05). The HPF in inflamed cyst, showed an increase in Ki67 expression and decrease in BCL-2 expression when compared with non-inflamed HPF (P<0.001). Conclusion: Moderate and severe inflammation can affect the overall proliferation activity of OKC epithelium. An increase in Ki67 expression and decrease in BCL-2 expression can be observed in inflamed OKC especially adjacent to basement membrane.

Background & Aim: The abrasive quality of children’s toothpaste has long been the concern of dental professionals. On the other hand, manufacturers have tried to improve the quality and establish ingredient standards. This study was designed to compare the abrasiveness of three locally produced toothpastes, namely Darugar, Pooneh and Kam with Oral-B standard. Materials and Methods: This experimental study was conducted using 24 samples of composite blocks imbedded in acrylic material. The weight of each specimen was measured by a digital scale at 0.0001gr accuracy. Each specimen was brushed with 200gr force along with the selected tooth paste solutions using V8 cross brushing machine. The weight of each specimen was measured after 5000, 10000, 15000 and 20000 strokes. The mean weight-loss as well as their standard deviations were calculated for each group. The collected data was then analyzed using ANOVA and Tukey statistical tests. Results: No significant difference was detected between four types of toothpastes after 5000 and 10000 strokes. However, significant differences were observed between Darugar toothpaste and the rest (Kam, Pooneh and Oral-B) after 15000 and 20000 strokes. Conclusion: Darugar pediatric toothpaste showed higher abrasive rate when compared with other toothpastes. The amount of wear was shown to be similar in Kam, Pooneh and Oral-B.

Background & Aim: Bone defect is one of the major problems facing dentists and maxillofacial surgeons. Several approaches, such as incorporating autografts, xenografts, as well as using polymers have been suggested. The calcified skeleton of corals has been proposed for bone grafting over the past few years. Toxicity is the most important concern of grafting foreign material. The purpose of this study was to investigate the toxicity of coral (madrepora) skeleton in fibroblast culture. Materials & Methods: Powdered corals with particle sizes of less than 100 micron were autoclaved. Coral powder was added to culture medium consisting of 90% RPMI, 10% FBS and different concentrations of 0.5, 1, 2, 5, 10, 20 and 50 milligrams per 100 milliliters of media were prepared. Fibroblast cells were obtained from Pasteur institute for inserting into culture mediums. Three samples were prepared from each concentration. Complete medium culture was the control. Ninety six well plate containing culture medium, fibroblasts and coral powder were prepared. They were placed into a programmed incubator containing 5% CO2 for 24, 48 and 72 hours at 370C. The (MTT) was then added to plate culture mediums. Since light absorption has close relationship with cells viability, ELISA reader apparatus was used to measure light absorption (optic dosimeter). The collected data was statistically analyzed using ANOVA test. Results: Light absorption in control group was similar to light absorption in the various concentrations of coral medium culture along with incorporated fibroblasts. Conclusion: Based on the findings of this study, it can be concluded that coral (madrepora) has potentially no cytotoxic effect on fibroblast cells.

Background & Aim: The baby bottle tooth decay is a prevalent type of caries, affecting most of the teeth in deciduous dentition, and it is mostly caused by overnight bottle feeding. Given the importance of implementing preventive procedures, the aim of this study was to determine the effect of varnish fluoride on prevention of baby bottle tooth decay in deciduous dentition. Materials & Methods: This experimental study was carried out on 52 kindergarten children aged one to three years-old in Tehran. The right maxillary centrals and laterals were considered as cases and the left counterparts as control group. Bifluoride-12 varnish (Voco, Germany) was applied twice over a 6 months period on the buccal and palatal surfaces of 104 case teeth. The results were compared with equal number of control teeth. Cochran–Q, Chi–square and Fisher's exact tests were used for data analysis. Results: After fluoride therapy, 3 (5.77%), 11 (21.16%), and 8 (15.38%) teeth developed new caries in laterals of case groups, centrals and laterals of control groups respectively. None of the centrals in the case group developed new caries. The observed group differences were statistically significant (P<0.001). According to Chi–square and Fisher’s exact tests, factors such as patients’ age, gender, geographic region, nutrition habits, oral hygiene and antibiotic consumption had no effect on caries prevalence (P>0.05). Conclusion: According to the findings of this study, it can be concluded that, fluoride varnish may be considered as effective preventive procedure in nursing bottle caries reduction in children with primary dentition.

Background & Aim: Halitosis is usually the result of vaporizing Sulfur Compounds (VSC) such as hydrogen sulfide and methyl mercaptan. The common solution to oral malodor problem is frequent rinsing with mouthwashes. The aim of this study was to compare the efficacy of three locally produced and commonly used mouthwashes with a zinc chloride 0.1% solution on in-vivo production of VSC. Materials & Methods: The selected mouthwashes under investigation were: (1) IR: an anti-plaque and tartar control mouthwash containing sodium benzoate and benzoic acid as the active ingredients; (2) NS: this mouthwash containing H2O2 stabilized with Ag+ions; and (3) CI: a herbal mouthwash. The positive and negative controls were zinc chloride (Zn) solution and distilled water (DW) respectively. The seven participants in the study were instructed to first rinse their mouth with 5 ml of 6 mM cysteine solution. They kept their mouth closed for 90 seconds, followed by taking baseline mouth air samples in order to be measured by a sulphide monitoring (VSC) device (Halimeter). Immediately after taking baseline measurements, subjects rinsed 10 ml of each test mouthwashes and solutions for 1 min on different days in a random crossover design. VSC measurements were repeated every 20 minutes up to three hours. Statistical data analysis was conducted using SPSS software, One-way ANOVA and Post-hoc LSD tests. Results: Data revealed that, there were significant differences between the tested agents only at 20, 40, 60, and 80 minutes after rinsing. The order of VSC inhibitory effect in the first hour was according to the following order: ZN>NS>DW>IR>CI while in the next two hours the order changed to: NS>DW>IR> ZN>CI. Conclusion: The results of this study showed that hydrogen peroxide mouthwash has the best anti-halitosis effect compared to others over the three hours of testing period, although the highest clinical effect was observed over the first 80 minutes of mouthwash administration.

Background & Aim: Different adjunctive treatment options have been proposed for treating periodontal diseases other than standard scaling and root planning due to higher incidence of periodontal conditions. Phenytoin is a drug primarily used for the treatment of epilepsy. However, its positive effect on wound healing process has encouraged researchers to recommend it for patients with periodontitis. The aim of this study was to assess the effect of Phenytoin 1% gel in the improvement of periodontal parameters in chronic periodontitis. Materials & Methods: In an experimental split–mouth study, 18 patients with moderate periodontitis having at least 2 contra lateral teeth, pocket depth of 4-5 mm and no history of systemic disease were selected. After standard scaling and root planning treatment, both right or left side of the oral cavity was randomly assigned for local delivery of phenytoin 1% gel and, the other side was selected as control. Pocket depth (PD) and connective tissue adhesion (CTA) indices were assessed at the baseline and also two, four and eight weeks after the first injection. The data were analyzed using Repeated Measures ANOVA and Paired T-tests, considering the baseline measures as covariates. Results: Using baseline PD and CTA values as covariates, significant reduction was observed in mean PD (P<0.05) and significant increase in mean CTA (P<0.001) during the study period. Also there were significant difference between the control experimental sites in terms of mean PD index and CTA (P< 0.001 for both). Conclusion: Using Phenytoin after standard scaling and root planning can relatively improve the status of Pocket depth and connective tissue adhesion.

Background & Aim: Facial vertical variables are important components of soft tissue analysis which are used in clinical esthetic evaluation. The purpose of this study was to evaluate the correlation between vertical skeletal and dental variables of hard and soft tissues of human face. Materials & Methods: A total of 46 patients (23 boys and girls) were included in this cross-sectional study. Selected angles and facial dimensions were measured during the clinical appointments. For facial proportions, from frontal view, selected reference points were marked on the face. The accuracy of this work was validated by an orthodontist. Hard tissue variables were also measured using patients’ lateral cephalograms. Finally, the correlations between soft and hard tissue variables were evaluated using correlation and regression analysis. Results: The statistical analysis showed correlations between number of vertical soft and hard tissue variables, with linear relationship among some of them. Significant correlation was detected between nasolabial angle of soft tissue and hard tissue N-Pog, N-B, N-A, N-Me and Lower incisor to Mandibular plane (P=0.014, P=0.013, P=0.046, P=0.015, P=0.037 respectively). Also, significant correlation was detected between soft tissue N-Me and hard tissue N-Me, and N-Pog; between soft tissue supraorbital ridge to subnasal and hard tissue N-A, and between soft tissue subnasal to menton and hard tissue A-Me and A-B (P=0.000 in all cases). The highest correlation was observed between soft tissue subnasal to menton and hard tissue A-Me (R=0.738). Conclusion: Given the results of this study, it can be concluded that some clinical parameters in vertical dimension, of facial hard tissue variables can be replaced by soft tissue counterparts in order to design the diagnosis and treatment plan according to soft tissue variable measurements.