Journal of Dental Medicine

Background and Aims: High level of caries was reported in pre-school children at the national level. Due to importance of focusing on high-risk children, this study was carried out to evaluate an oral health promotion program designed for Ameneh orphan center.

Materials and Methods: Two centers were chosen and assigned to intervention (Ameneh orphan center) and comparison (Shobeir orphan center). Dental examination has been carried out using dental mirror and blunt probe under artificial light and dmfs index was recorded. Health promotion program including topical fluoride application after dental treatment as well as power point education session for caregivers was delivered in intervention group. Children in the other center were only received routine dental treatment. Data were analyzed using Mann-Whitney and regression tests.

Results: 79 children in the intervention group and 51 children in comparison group were evaluated in the study. The mean age of children in the intervention group was 4.7 (SD=1.6) and in the comparison group was 4.6 (SD=1.2). The dmfs index in the intervention and comparison groups was 6.86±10.23 and 8.75±12.42 (NS), respectively. The mean dmfs after intervention in the intervention group was 7.93±11.21 and in the control group was 9.88±12.51, which showed no significant difference (P>0.05). Comparison in subgroups showed that the mean dmfs in the group received fluoride varnish in addition to complete dental treatment was significantly less than the comparison group (P<0.05). Controlling the effect of baseline caries and age on the outcome variable with regression analysis showed that the effect of baseline caries should be considered when comparing two groups.

Conclusion: Oral health promotion programs including topical fluoride application can be used in high-risk groups of children.

Background and Aims: The present study aimed to evaluate the barriers to the production of scientific dental articles in dental schools in Iran based on the opinions of dental postgraduate students.

Materials and Methods: A self-administered questionnaire was distributed among postgraduate students of all Iranian dental schools in June 2010. The respondents rated their agreement with eight sentences about what hinder them from producing scientific dental articles based on a 5-grade Likert scale. The data were analyzed using Chi-square test.

Results: Totally, 270 filled questionnaires from 14 dental schools were received. Of all respondents, 53% were male, the mean age were 29.6 ± 3.8. About half of the respondents reported at least one published article. Less than half of the respondents reported producing an article from undergraduate thesis more women than men and more younger than older students (P<0.03). About two-third of the respondents rated absence of an English editing center, no financial incentives, no appropriate environment, and no competency for scientific writing as most prevalent barriers to the production of scientific dental articles.

Conclusion: To expand the share of Iran in the production of scientific dental documents, the potential of postgraduate dental students must be regarded and suitable condition for scientific writing must be provided. Specifically, based on the findings of the present study, provision of an English editing facility, establishing financial incentives, and providing the students with appropriate environment and efficient scientific writing education are of utmost importance.

Background and Aims: The aim of the present study was to investigate self-perceived need to learn practice management and self reported knowledge in this regard among dentists.

Materials and Methods: A group of five academic staff members of Community Oral Health Department (Tehran Dental School) and four dentists formed an expert panel to develop the content of the course. This group developed a list of topics related to principles of successful dental practice. To investigate the necessity of educating the topics and self-assessed knowledge of the topics, a questionnaire was designed and administered to 55 volunteer dentists. Forty six dentists completed the questionnaire. T-test and Chi-square test were used for statistical analyses.

Results: Totally more than two-third of the dentists believed that a huge need exists for education of all the topics. The corresponded figure for such topics as ergonomics and medical emergencies was about 90%. About 80% of the dentists felt that they had a vast knowledge of safety and infection control. On the other hand, 54.3% of them reported weak knowledge regarding professional rules and regulations. Self-reported educational need and knowledge of the dentists did not show significant association with their age, gender, and work experience
(P>0.05).

Conclusion: The dentists believed in the necessity of educating such topics and evaluated their knowledge as deficient in these areas. This shows the necessity of developing courses on these topics.

Background and Aims: When composite resin polymerizes, shrinkage stresses tend to produce gaps at the tooth/ restoration interfaces. Surface sealants may reduce or avoid problems related to the marginal interface. The aim of this study was to evaluate the effect of two different surface sealants (Fortify and Optiguard) on the microleakage of class V resin composite restorations.

Materials and Methods: Twenty three sound noncarious molars were collected. Totally, 45 Class V cavities with the occlusal margins in enamel and cervical margins in cementum were prepared in both buccal and lingual surfaces. The specimens were randomly assigned in three groups (15 cavities in each group) and then restored with a resin composite. After the finishing and polishing procedures, the restorations in each group were covered with a specific surface sealant, except for the control samples, which were not sealed. After placing restorations, the specimens were thermocycled and then immersed in a 50% silver nitrate solution (tracer agent) for four hours, sectioned longitudinally and analyzed for leakage using a stereomicroscope in a blind manner. The marginal microleakage was evaluated at the occlusal and cervical interfaces and compared among the three groups using the Kruskall-Wallis and the Mann-Whitney U tests.

Results: Microleakage was found in all groups at both occlusal and cervical margins. Significantly greater leakage was observed at the cervical margins compared to the enamel margins of the material groups (P=0.005). There was no statistically significant difference among the groups at occlusal margins (P=0.66). In the cervical region, Fortify showed improved results and statistically presented the lowest degree of microleakage (P=0.003).

Conclusion: The used sealant materials presented different rates of effectiveness and Fortify decreased marginal microleakage significantly.

Background and Aims: Radiographic examination is a necessary step in diagnosis of horizontal root fracture. The purpose of this study was to determine the sensitivity and specificity of single radiograph for detection of horizontal root fracture.

Materials and Methods: In this analytical-descriptive study, 30 human freshly extracted teeth were used. Using a hammer and clamp, the teeth were divided into two sections accidentally and then sections were attached together by cyanoacrylate glue. Two radiographs were taken with and without a piece of human mandibular bone. Afterward, radiographs were analyzed by three expert dentists using a slide show device.

Results: The diagnostic sensitivity and specificity of single radiograph for detection of horizontal root fracture without bone was 100%, but in radiographs of teeth with bone was 82.7% and 100%, respectively.

Conclusion: Based on the results of this study, in most cases, the horizontal root fractures can be detected by a single periapical radiograph.

Background and Aims: Working length determination and remaining this length is of great importance in root canal therapy. Recently, electronic apex locators are being used to determine working length and decrease the number of radiographs. The purpose of this study was to compare the sensitivity of Root ZX and Novapex electronic apex locators with radiography in a clinical study.

Materials and Methods: In this study, 73 single-canalled teeth of the patients referred to the endodontic department of the Yazd Dental School were evaluated. The access cavity was prepared and working length of the root canals were measured by using the apex locators: Root ZX and Novapex. The file was placed in the root canal and a periapical radiograph was taken using parallel technique. The working lengths obtained by apex locators were recorded and compared with those of radiographs. The data were analyzed by Pearson's correlation coefficient, Wilcoxon test and paired t-test.

Results: The exact measurement without any fault was 46.6% for Root ZX and 20.5% for Novapex compared to radiography. In the range of 0.5 mm fault, the results were 91.8% for Root ZX and 64.4% for Novapex compared to radiographic measurements. The difference between the average of the measured lengths by Root ZX and radiography was not significant (P=0.17). On the other hand, the results showed significant difference between the average of the measured lengths by Novapex and radiography (P=0.017). The difference between two apex locators was not significant (P=0.061).

Conclusion: Root ZX and Novapex with high accuracy are useful for determining working length of the root canals in pregnant patients with special anatomic conditions and patients with muscle disharmony. Therefore, the use of these apex locators combined with radiography is recommended in root canal treatment.

Background and Aims: Recurrent aphthous stomatitis (RAS) is the most common oral mucosal inflammatory disease. The frequency of RAS is as much as 20% in the general population. The cause of RAS is not yet fully understood. Antioxidant is a material which has ability to preserve molecules from damage and also can delay the start of it. The aim of this study was to compare saliva level of total antioxidant status (TAS) in RAS patients with that of normal subjects.

Materials and Methods: In this case-control study, 25 patients with aphthous stomatitis were considered as the case group and 25 healthy subjects as control group. The case and control groups were matched by sex and age. Total antioxidant status (TAS) saliva levels were measured in two groups by spectrophotometer. The data were analyzed with independent sample t-test.

Results: The mean and standard deviation of TAS in case group was 1.64±0.64 µmol/L and in control group was 1.49±0.3 µmol/L. There was not significant difference between case and control groups (P=0.464).

Conclusion: Results of this study showed that there was no statistically significant difference between RAS patients and healthy subjects in saliva antioxidant status levels.

Background and Aims: Improper feeding is one of the most important etiologic factors in early childhood caries (ECC). In some clinical trials, breast feeding (BF) is mentioned as a causing factor in ECC. Results in this topic are different or even controversial. It is vital that all general advices given out are consistent with general health education messages. The aim of this study was to conduct a systematic review on the relationship between breast feeding and early childhood caries. 

Materials and Methods: Articles, guidelines, related books, and specific databases such as SID, PubMed, Scirus, Elsevier, American Association of Pediatric Dentistry (AAPD), American Association of Pediatrics (AAP) and American Dental Association (ADA) were searched for related topics cited since 1990. Early childhood caries definition, breast feeding and other variables such as sample size, study location and study design were analyzed.

Results: According to data analysis, there was a lack of methodological consistency and inconsistent definitions of ECC and BF in the literature making it difficult to draw conclusions. Results about relationship between prolonged BF and ECC were inconclusive. There was a positive relationship between nocturnal BF and ECC. A history of BF did not have any effect on the caries incidence.

Conclusion: Because of the role of breast feeding in children^'s health, it is important to inform the parents about the possibility of dental caries due to nocturnal breast feeding.

Background and Aims: The oral impact on daily performance (OIDP) is one of the oral health-related quality of life indices to measure physical, social and mental consequences of the oral health status. This study aimed to evaluate the OIDP index in patients referring to Tehran dental school.

Materials and Methods: Four hundred and ninety nine patients referring to patients' clinic in Dental School of Tehran University of Medical Sciences in spring 2011 participated in this study. They were interviewed for demographic factors including age, gender and level of education, and OIDP index questionnaire before receiving any treatment. Statistical analysis was carried out by means of linear regression modeling.

Results: 85.6% of patients confirmed that they had at least one oral impact on daily performance during the last 6 months. The most prevalent performances affected were eating (50.1%) and smiling and showing teeth without shame (12.8%). The mean OIDP score for the population was 5.6 ranging from 0 to 36. Linear regression modeling controlling for age, gender and years of education revealed that older patients and those with lower education had significantly higher OIDP scores.

Conclusion: The effect of oral health on daily performance was clear. The association among age, education and oral impact on daily performance indicates the need for more comprehensive preventive oral health care for adults with lower educational level.

Background and Aims: Normative need assessments should be substituted or integrated by patient-based outcome measures regarding their shortages in health-oriented approach . This study aimed to assess and compare the ability of  an index of oral health-related quality of life measured by Child Oral Health Impact Profile (COHIP) questionnaire and the Aesthetic Component of Index of Orthodontic Treatment Need (AC-IOTN) to identify the normative need to orthodontic treatment using Dental Health Component-IOTN in a sample of the Iranian adolescents.

Materials and Methods: Target population of this cross-sectional analytic study was 597 of the 13 to 18 year-old schoolchildren enrolled in middle and high schools of the city of Isfahan, Iran. They completed the COHIP questionnaire and then were examined by two calibrated trained dentists (agreement coefficient:0.9) to record the DHC grading. The students scored their AC in according to the images of the scale. The association between subjective indicators and clinically defined need were evaluated by the correlation analysis and the statistics for the diagnostic validity of tests.

Results: Of 568 examined students, 16.7% and 2.1% had definite need according to DHC and AC criteria, respectively. 10% of orthodontic patients had perceived distinct impact on their quality of life. The significant association (P=0.001) between the severity of malocclusion and quality of life was at moderate level by AC (R=0.37), but it was not convincing enough by DHC (R=0.16). The specificity of AC to detect the healthy ones showed to be excellent but its low sensitivity disabled the recognition of patients, precisely.

Conclusion: The considered patient-based indices did not meet the competencies to define the orthodontic need in the adolescents, but it could be employed to identify the persons with impaired quality of life and it would probably benefit  the process of prioritization.

Background and Aims: Various methods are used for treatment of open bite. The objective of this study was to investigate the effects of Lower Anterior High Pull Headgear (LAHPH) appliance in Class I subjects with moderate open bite and high lower lip line.

Materials and Methods: The study group was composed of 10 subjects with a mean age of 15.8±2.5 years and 3.05 ± 0.07 mm moderate open bite. All the patients rejected orthognathic surgery. The treatment included extraction of upper and lower second premolars followed by leveling, banding, bonding, posterior space closure, and anterior retraction. After these procedures, the open bite was reduced to 2.04±1.17 mm. Afterwards, LAHPH was applied for 18 hours per day for 8±2 months. LAHPH appliance was composed of High Pull Headgear and two hooks mounted on its inner bow. Two elastics (1.8, light, Dentaurum) connected the upper hooks on the inner bow to the lower hooks on the mandibular canines vertically. The forces produced by the prescribed elastics were 10 and 60 g during mouth closing and opening, respectively. Paired T-test was used to evaluate pre-and post-treatment outcomes.

Results: The pre-and post-treatment cephalometric evaluations showed that the LAHPH reduced effectively the open bite of the patients to 0.15±1.7 mm (P<0.001).

Conclusion: This appliance can be used as an acceptable method for closing the open bite in Class I subjects.

Background and Aims: The purpose of this study was to design a new device assisting dental students to measure the tapering of the prepared teeth for fixed crown prosthesis in which the desired tapering for better clinical prognosis could be obtained.

Materials and Methods: The designed device in this study had two arms that were placed on two opposite walls of the prepared teeth. To evaluate the validity and reliability of this device, 3 dies with different degrees (13, 29 and 45°) were used and 20 teeth were prepared by dental students with undefined tapering degrees. The measurements of tapering were performed by six last year-dental students in two different time periods. Comparison of errors in measurements on standard dies between observers and between time intervals were analyzed by (Wilcoxon) Paired t-test with a significance level of α=0.05.

Results: For the three dies used in this study, we compared the differences for each measurement taken by observers with the standard taper of the dies. Maximum difference of measurements with true standard die tapering was 1 degree. A number of 6 measurements were under the true standard tapers and 2 measurements were above it. Interclass Correlation Coefficients (ICC) of the first and second measurements on prepared teeth were 97.4 and 97.5, respectively.  There were no significant differences between different observers or two measurements of the same observer in different time intervals (P>0.05).

Conclusion: The results indicated that this device can be valid and reliable for measuring the angle of convergence of the prepared teeth and can be used as an educational device in dental schools as a replacement for previous tapering measurement methods.

Background and Aims: Apical root resorption is an adverse side effect of fixed orthodontic treatment which cannot be repaired. The aim of this study was to use panoramic radiographs to compare the root resorption before and after the orthodontic treatment with standard edgewise .018 appliance.

Materials and Methods: The before and after treatment panoramic views of sixty-three patients needed fixed orthodontic treatment included 1520 teeth were categorized into 3 Grades (G0: without resorption, G1: mild resorption with blunt roots or ≤ 1/4 of root length, G2: moderate to severe resorption or > 1/4 to 1/2 of root length. Relationship between root resorption and sex and treatment duration was analyzed with Mann-whitney and  Spearman's correlation coefficient, respectively.

Results: The findings showed that 345 teeth were categorized as Grade 1.  Grade 2 of root resorption was not found in this study. The highest amount of root resorption was recorded for the mandibular lateral incisor. In both gender, the root resorption of the mandible was more than that of the maxilla. The males showed significantly higher rate of resorption than the females (P<0.05). Root resorption was not significantly related to the treatment duration and the side of the jaws (P>0.05).

Conclusion: The mandible and male patients showed higher amount of root resorption. In addition, root resorption was not related to the treatment duration and the side of the jaws.

Background and Aims: Using the conservative adhesive resin restoration (CAR) in uncooperative children lead to numerous problems because of being time consuming. The purpose of this study was to compare the microleakage of conservative adhesive resin restoration under separate curing and co-curing.

Materials and Methods: In this experimental study, 120 intact premolar teeth were collected and 120 vertical grooves were prepared on them. Then the teeth were divided into four groups: group 1, separated curing of bonding agent, flowable composite and sealant group 2, co-curing of all materials for 60 seconds group 3,
co-curing of all materials for 40 seconds and group 4, co-curing of all materials for 20 seconds. Then the specimens were thermocycled and immersed in basic fuchsin solution. The teeth were sectioned horizontally and dye penetration was evaluated with stereomicroscope. Date were analyzed using one-way ANOVA and Scheffe test.

Results: Mean value of dye penetration in groups 1, 2, 3, and 4 was 1.53±0.6, 2.06±0.6, 2.5±0.7 and 3.53±0.6, respectively. There was a statistically significant difference between group 1 and the other groups (P=0.0001).

Conclusion: Considering the problems caused by microleakage in conservative resin adhesive restorations, co-curing method should not be used. In the case of using co-curing method, 60 second curing time is suggested for sufficient polymerization.

Background and Aims: Adequate retention of the post is a prerequisite for the clinical success which might be affected by the type of root canal filling material. The aim of this in vitro study was to compare the effects of gutta-percha and Resilon on retention of quartz fiber posts.

Materials and Methods: In this experimental study, 44 maxillary central incisors were sectioned at the CEJ level and prepared endodontically using ProTaper rotary files. The specimens were then randomly assigned into two experimental groups (n=22): group R, the root canals obturated with Resilon and group G, the root canals obturated with gutta-percha. After preparing the post space and insertion of quartz fiber posts, the coronal 10 mm of the root was sectioned perpendicular to the long axis to produce disks of 2.3 mm thickness.Then the specimens were submitted to the push-out test (1mm/min) using a universal testing machine. The data were analyzed using Mann-Whitney U test.

Results: There was a significant difference between the retention of posts in groups R (7.08±5.1) and G (4.8±3.3) (P=0.04).

Conclusion: Quartz fiber posts showed significantly higher retention in teeth obturated with Resilon compared to those obturated with gutta-percha.

Background and Aims: The aim of this study was to measure the degree of conversion (DC) of three types of composite resins (micro-hybrid, nano-hybrid and Ormocer) with different light curing units (LED LCU and QTH LCU) in two depths.

Materials and Methods: Three commercially available dental resin composites were used in this study: (Tetric Ceram, Ivoclar Vivadent, Liechtenstein-A2 shade), (Tetric Evoceram, Ivoclar Vivadent, Liechtenstein-A2 shade), (Ceram X, Dentsply, Germany-M₂ shade). Specimens were divided into two groups, 5 specimens were photo-activated by QTH unit (Coltolux 75-Colten) and the other five specimens were cured by LED (Demi-Kerr). Then each specimen was sectioned at the top surface and at 2-mm depth. The DC was measured by FT-IR
(Bruker-tensor 27). The data were analyzed by 3-way ANOVA test.

Results: There was significant difference between tested composite resins (P<0.001). The results of top surfaces were significantly different from those observed at 2-mm depth (P<0.001). The type of curing unit affected the polymerization of Ceram X resin composite.

Conclusion: This study showed a significant difference in the degree of conversion in different thicknesses within three groups of resin composites.

Background and Aims: Accurate recording of implant location is required to achieve passive fit and have the implants without stress concentration. The aim of this in-vitro study was to evaluate the dimensional and angular accuracy of open-tray and closed-tray impression techniques using polyether impression material and also to assess the surface detail reproduction of the tooth while impression making.

Materials and Methods: One reference metal model with 2 implants (Implantium) on the position of the maxillary second premolar and first molar and one molar tooth for evaluation of surface details was prepared. 27 polyether impressions of these models were made (9 using open-tray, 9 using closed-tray techniques and 9 were made just of the surface of the teeth without any implants). Impressions were poured with ADA type IV stone. Coordinate Measuring Machine was used for measuring the dimensional accuracy and video measuring machine for surface detail reproduction. All of these measurements were compared with the measurements on the reference model. Data were analyzed by and compared by T-test and One-way ANOVA.

Results: There was a significant statistical difference between open-tray and closed-tray techniques (P<0.001). There was no significant difference in the surface detail reproduction of open-tray and Closed-tray techniques and impression making with or without the implants (P>0.05).

Conclusion: The accuracy of open-tray impression technique was more than closed-tray technique. The surface detail reproduction of the tooth was not affected by impression technique.

Background and Aims: Increasing demands for health care's services on one hand and limited resources on the other hand brings about pressure over governments to find out a mechanism for fair and appropriate distribution of resources. Economic analysis is one of the appropriate tools for policy making on this priority. The aim of this study was to assess capital and consumption of oral health units of health care centers in Yazd city and comparing it with revenue of these centers and determining of cost effectiveness.
Materials and Methods: In this descriptive cross sectional study, all health care centers of Yazd city with active dentistry department were evaluated.  The data has been extracted from current documents in health care center of county based issued receipts and daily information registers.
Results: Expended cost for providing of oral hygiene services in second half of 2008 in 13 medical health centers of Yazd included active dentistry section was 557.887.500 Rials and revenue to cost ratio was about 34%. The most provided service was related to tooth extraction and the average of tooth restoration in each working day was 0.48.
Conclusion: With attention to low tariffs of dentistry services in medical health centers and paying subsidy to target groups, expenses of oral hygiene are always more than its revenue.

Background and Aims: The aim of this in vitro study was to assess the shear bond strength of amalgam to dentin using four dentin adhesive systems.
Materials and Methods: One hundred human molars were selected. After enamel removal, a dentin cylinder with 3 mm thickness was prepared. Eighty specimens were resorted with amalgam and four dentin adhesive systems as follows (n=20): group 1, Scotch Bond Multi-Purpose group 2, One Coat Bond group 3, PQ1 and group 4, Panavia-F. In group 5, 20 specimens were resorted with amalgam and varnish as control group. The specimens were incubated at 37°C for 24 h. The shear bond strengths were then measured by using push out method. The data were analyzed by one-way ANOVA and post hoc Duncan's tests.
Results: Mean values for bond strengths of test groups were as follows: group 1=21.03±8.9, group 2=23.47±9, group 3=13.16±8.8, group 4=20.07±8.9 and group 5=14.15±8.7 MPa±SD. One-way ANOVA showed the statistically significant difference between the bond strengths of five groups (P=0.001). Post hoc Duncan's test showed significant difference between groups 1and 3 (P=0.008), groups 1 and 5 (P=0.019), groups 2 and 5 (P=0.0008), groups 4 and 5 (P=0.042), and groups 3 and 4 (P=0.018).
Conclusion: Results of this study showed that the bond strength of amalgam to dentin using One Coat Bond as dentin adhesive system was higher than that observed in other dentin adhesive systems.

Background and Aims: The purpose of this experimental study was to investigate the shear bond strength of three new adhesive systems to enamel and dentin of permanent human teeth using three new etch and rinse and self-etch adhesive systems.
Materials and Methods: Sixty intact caries-free third molars were selected and randomly divided into 6 groups. Flat buccal and lingual enamel and dentin surfaces were prepared and mounted in the acrylic resin perpendicular to the plan of the horizon. Adhesives used in this study were Tetric N-Bond, AdheSE and AdheSE-One F (Ivoclar/Vivadent, Schaan, Liechtenstein). The adhesives were applied on the surfaces and cured with quartz tungsten halogen curing unit (600 mW/cm² intensity) for 20 s. After attaching composite to the surfaces and thermocycling (500 cycles, 5-55ºC), shear bond strength was measured using a universal testing machine at a crosshead speed of 0.5 mm/min. The failure modes were examined under a stereomicroscope. The data were statistically analyzed using T-test, one-way ANOVA, Tukey and Fisher's exact tests.
Results: In enamel, Tetric N-Bond (28.57±4.58 MPa) and AdheSE (21.97±7.6 MPa) had significantly higher bond strength than AdheSE-One F (7.16±2.09 MPa) (P<0.0001). Tetric N-Bond had higher bond strength than AdheSE but there was not any significant difference between them (P=0.093). In dentin, there were significantly differences among all adhesives (P<0.001). Tetric N-Bond (20.62±3.03 MPa) showed the highest and AdheSE-One F (6.54±1.13 MPa) had the lowest value. The bond strength in enamel was higher than that observed in dentin and the difference was significant in Tetric N-Bond (P=0.044) and AdheSE (P=0.000) groups. There were no significant differences in the mode of failures among groups (P>0.05).
Conclusion: Shear bond strength to dentin in Tetric N-Bond (etch and rinse system( was higher than self-etch adhesives (AdheSE and AdheSE-One F). The bond strength to enamel and dentin in two-step self-etch (AdheSE) was higher than one-step self-etch (AdheSE-One F).