مجله دندانپزشکی دانشگاه علوم پزشکی تهران
سال بیست و سوم شماره 4 (پیاپی 65، زمستان 1389)

It is important to use intracanal medicaments in teeth with necrotic pulp. Calcium hydroxide is the intracanal medicament of choice in such cases. Also, Mineral Trioxide Aggregate (MTA) is a suitable root canal filling material because of its favorable characteristics. MTA can be used in some cases where calcium hydroxide is used. The purpose of this study was to evaluate the Ca++ and OH ˉ diffusion through root dentin using calcium hydroxide paste and two different brands of MTA as root canal filling materials. In this in vitro study, the root canals of 52 single-rooted teeth were instrumented and shaped. External defects were created on the middle one-third of the root surface. 17% EDTA and 5% NaOCl were used to remove the smear layer. All surfaces except the external defects were sealed and the teeth were placed in normal saline. Ten teeth were selected as the control group. Forty-two remaining teeth were divided into three groups of 14 teeth each (A,B, and C groups). ProRoot MTA was placed in group A. Angelus MTA was placed in group B and Calcium hydroxide paste was placed in group C. After sealing the coronal access, all specimens were placed in normal saline solution. Ca++ concentration and pH were determined after 24 hours, 48 hours and one week in all groups. The data were analyzed with Repeated Measure ANOVA and Pair T- tests. Ca++ release and pH in group C was significantly higher than those in groups A and B in all time periods (P<0.001). The difference between groups A and B was not significant (P>0.05). The results of this study indicate that in necrotic cases with lesion which MTA is indicated (open apex and perforation), calcium hydroxide might be better used as an intracanal dressing before using MTA as a permanent filling material.

Failure of bonding between artificial teeth and denture base material is a considerable problem for patients who wear dentures. Because of the cost of denture repair and the expensive price of foreign artificial teeth, this study was designed to compare the bond strength of composite and acrylic artificial teeth with heat-cured and auto-polymerized denture base resins. In this experimental and in vitro study, two type of acrylic resin (heat-cured: Selectaplus H/ Trevalon, Dentsply and auto-polymerized: Rapid Repair, Dentsply) and four artificial teeth (acrylic Marjan New, composite Glamour teeth which both of them are Iranian) and Ivoclar acrylic and composite teeth were used. Therefore, 8 groups of 14 specimens each were evaluated. A shear bond strenghth test in a Universal Testing Machine was used. Data were analyzed using the 2-way ANOVA test. The bond strengths of acrylic teeth (Marjan New and Ivoclar) to heat-cured resin were similar (P=0.632) and statistically higher than those of composite teeth (Glamour and Ivoclar). Acrylic teeth (Marjan New and Ivoclar) and Glamour teeth had similar bond strength to auto-polymerized resin, which showed the highest bond strength values. Ivoclar composite teeth showed significantly the lowest bond strength (P<0.05). All acrylic teeth had the highest mean bond strengths to heat-cured resin which were significantly different from that of auto-polymerized resin (P<0.05). However, the bond strengths of all composite teeth to both denture base resins were not significantly different (P>0.05). Based on the results of this study, the type of denture base material and artificial tooth may influence the failure load.

This ex vivo study was done to evaluate the effect of different adhesive systems on microleakage of class V composite restorations. Thirty extracted human third molar teeth were selected and class V cavities were prepared (3×3×1.5 mm) on buccal and lingual surfaces. Then, teeth were divided into 3 groups. Adhesives used in this study were Excite (Ivoclar/Vivadent), AdheSE(Ivoclar/Vivadent) and AdheSE-one Ivoclar (Vivadent/Vivadent). After application of adhesives, cavities were restored with a resine composite (InTen-S A1/ Ivoclar), in 3 increments and cured with QTH light curing unit (700 mW/cm). After 24 hours storage of teeth in 370C water, teeth were thermocycled (500 cycles in 5-550C) and stored in 1% basic fushin for 24 hours. After that, the specimens were rinsed with running water and mounted in a self-cured acryl. Finally, the specimens were sectioned and maximum depth of dye penetration for each restoration was measured using stereomicroscopy. The results were statistically analyzed with Mann-Whitney U test. In comparison between enamel and dentin margins in each group, microleakage in enamel margins were less than that of dentin margins. This difference was statistically significant in Excite and AdheSE-one groups (P=0.001, P=0.043). AdheSE showed the least microleakage in dentin margins however, there was no significant difference between 3 bonding agents (P=0.14). In enamel margins, there were significant differences between 3 bonding agents (P=0.001). Excite showed the lowest microleakage and AdheSE-one had the highest microleakage. The least enamel microleakage was associated with the total-etch and least dentin microleakage was observed in the two-step self-etch adhesive system.

Caries and bone loss are the most common diseases in oral cavity. The prevalence of these diseases will be reduced by controlling their risk factors. In this study, bitewing radiographs of patients were examined to illustrate the relationship between caries and bone loss. One-hundred and fifty bitewing radiographs of 86 patients were evaluated. In these radiographs, caries and distance between alveolar crest and CEJ were measured. In addition, confounding variables (contact type, tooth type, tooth surface) were assessed. Furthermore, patients were asked about the use of other possible risk factors of bone loss like smoking, brushing, and flossing. The data were analyzed using Regression analysis. Findings of this study showed that the relationship between caries and bone loss was significant (P=0.02). Also, there were significant relationships between flossing (P=0.03), tooth type (P=0.0001) tooth surface (P=0.02) and bone loss. Finally the multivariate analyses considering confounding variables illustrate significant relationship between caries and bone loss (P=0.0001). Caries and bone loss have important roles as the risk factors for each other. Thus, it is necessary to prevent these risk factors and treat them as soon as possible to reduce these diseases.

Fissure sealant therapy is a national program in elementary schools in Iran. Therefore, evaluation of the parent's knowledge and attitude is necessary to improve the program. In this cross-sectional and descriptive-analytic study, Iranian students were chosen in a randomized cluster manner. The questionnaires were filled-out by student's parents to evaluate their general information, knowledge, and attitude. Moreover, students were examined for having any fissure-sealed teeth. Data were collected and analyzed by multiple logistic regression tests. 414 boy students and their parents were participated in this study. 57.6% of parents knew that fissure sealant prevents the caries and 44.5% believed that fissure sealant is important to prevent caries. However, only 8.9% of children had fissure sealant. Parent's knowledge was significantly related to the source of oral health information and oral health education. Regular dental visits and high level education was effective in increasing the knowledge about sealant therapy. There was a significant relation between parent's attitude toward fissure sealant and level of education, oral health education and numbers and times of dental visit (P<0.001). There were a significant relation between tooth sealing and parent's oral health information. Regular dental visits and oral health education have positive role in parent's knowledge and attitude and practice. So parents must be encouraged to have regular dental visit and dentists must be emphasized to give them necessary education. School is the best place for giving proper information to parents.

Association between patient satisfaction and success of the treatment determines the quality of health care. Measuring the level of satisfaction is an important factor for improving the quality of services provided by a system, so it is necessary to determine the expectations of patients. The aim of this study was to evaluate the patient satisfaction from services provided by the dental faculty of Tehran University of Medical Sciences. In this descriptive and cross-sectional study, 385 patients were randomly selected from different departments of dental faculty including prosthodontics, endodontics, periodontics, operative dentistry, radiology and oral medicine. A two-part questionnaire including demographic characteristics of patients and satisfaction from reception process, infection control, student and personnel behavior, and the outcome of treatment was filled out by patients. Data were analyzed using SPSS software. The most dissatisfying factor was the time wasted in paying the cost and the most satisfying factor was student behavior. General satisfaction form the process was evaluated (complete satisfaction 51.9%, partial satisfaction 38.4% and dissatisfaction 9.6%), and 62.9% of patients were completely agree with introducing dental faculty to others. The most satisfying item was student behavior which indicates that this factor is of great importance in increasing the quality of treatment. The deficiencies determined by patient can provide reliable data for determination and regulation of health care policies.

The precision of periodontal pocket measurements with periodontal probe is related to different factors. Some of these are related to examiner. The purpose of this study was to compare the right-handed and left-handed dental students in the measurement of periodontal pocket depth (PPD). Eight systemically healthy adult patients (mean age of 35 years) with 0.5-6 mm periodontal pocket depth and a minimum of 20 teeth were examined by 4 right-handed and 4 left-handed students of dentistry (mean age of 25 years). These students were trained for periodontal examination probe depth measurements with Williams probe. Measurements were inserted in SPSS software and analyzed with Iintraclass correlation coefficient (ICCS) and T-test. There was statistically significant difference in the measurement of PPD between right-handed and left-handed examiners in the whole mouth (P<0.05), but this difference (0.08 mm) was not clinically significant. The most difference was found in the posterior teeth of mandible at right quadrant (mean=0.2 mm). Analyses of each pair of same handed and different handed examiners with T-test and ICCS showed that these measurements were nearly similar and reproducible. There was no clinically significant difference in measurement of PPD between right-handed and left-handed examiners.

Multiple supernumerary teeth are rare and often found in association with syndromes such as Gardner, Cleidocranial dysplasia and cleft lip and palate, with a much less chance for isolated non-syndromic cases. The aim of this study was to report a case with 6 supernumerary teeth without syndromic association.Case Report: The patient was a 33 year-old female, referred to oral diseases and diagnosis department with chief complaint of sensitivity to cold and hot food in right upper premolar region. Oral examination revealed 5 erupted lingually supernumerary teeth (four in mandibular and one in maxillary premolar region, respectively). Further panoramic radiography clarified an extra impacted tooth in the palatal region of left premolar maxillary area. All extra teeth had been appeared since the age of 17 during one year, as the patient claimed. Medical history and thorough clinical and paraclinical examinations were not significant except for the hypothyroidism, since 5 years ago. No other family member noticed to be the case. Based on our findings, a diagnosis of non-syndromic multiple supernumerary teeth was established. A thorough examination of each patient presented with supernumerary teeth, including panoramic and intraoral radiographic images may provide valuable information regarding accompanying syndromes and unerupted teeth. Early diagnosis is an essential step for orthodontic or surgical decisions making, preventing or avoiding worsening complications such as malocclusion, adjacent normal teeth delayed eruption or rotation, diasthema, cystic lesions and resorption of contiguous teeth.