Journal of Dental Medicine

Polymerization contraction may produce defects in the composite - tooth bond. This may lead to bond failure and microleakage. The aim of this study was to reduce microleakage of posterior composites using different methods. 45 molar and premolars extracted teeth were choosen. The cavities were randomly assigned into 5 groups of 9. Box-shaped cavities were prepared on each side of proximal surfaces and restored by five different methods. Group 1 was filled by a light-cured composite and dentin bonding agents (DBAs) with light curing from the occlusal area. Group 2 was filled by a light-cured {LC} composite and DBA, in addition the angle between the light source and occlusal area was 45 degree. After conditioning of teeth in-group 3, LC glass ionomer was placed on the gingival floor and then filled by a light-cured composite and DBA. In group 4, after conditioning, the teeth were lined by a LC glass ionomer and then self-cured composite was placed on gingival floor. This group was filled with LC composite. In Group 5 DBA was used followed by placing a self-curing composite on gingival floor and filled by LC composite. The teeth were subjected to 500 thermocycling (5°C and 55°C with dowel time 30 s) and stored in 0.5% basic fushin for 24 hours. Dye penetration was evaluated by light microscope. The results were tested by Kruskat-Wallis one-way analysis of variance by rank. The comparison between treatment groups showed highly significant difference {P<0.0001). No significant difference was found between groups 3 versus 4 and groups 1,2,5 versus 3,4. Group 3 showed the least microleakage score. Therefore least microleakage was obtained by the group which used L C glass ionomer and DBA followed by filling a composite.

Discoloration of composite resins is considered to be a major factor in esthetic restoration failures. The aim of this study was to evaluate color stability of IDM composite (both light and self cure samples namely IL and IS), and to compare it with a self-cure composite (Degufill named DS) and a light cure ormocer composite (Definite, called DL in the Report). 60 disk shaped samples of each composite were prepared, according to ISO-7491. The samples were divided into 3 groups and aged as follows: A- (Control) 7 days in dark 37°c chamber B- Foil covered and kept in 100% humidity, and 37°c in xenotest chamber for 24 hours, then transferred to a dark 37°c chamber for 6 more days.C- Kept in 37°c, 100% humidity under the emission of xiiion lamp of xenotest chamber for 24 hours,and then transferred to 37°c dark chamber for 6 more days The lightness and chromaticity values of samples were measured both before and after aging using a spectrophotometer (Data Flash). The total color changes as well as changes in lightness and chromaticity values were measured in the CIE L * a * b * scale, and analyzed. Color change was recorded to be significant in all samples after aging. The maximum change belonged to IL, which was significantly
different from DL and DS. It seems, in order to have a durable esthetic restoration using IDM, more scientific and professional consideration is needed in the production process.

IgA selective deficiency is the most common immunodeficiency. The prevalence of it in different races varies from  to . Since secretary IgA has has a defensive role in the mucosal surfaces, supposing is thought that IgA deficiency will be accompanied by oral manifestations. The previous studies showed controversial results about that. The aim of this cohort study was to finding out oral manifestations in IgA- deficient individuals. As s result oral specialists can find the patients in early stages. 11 IgA- deficient patients (with IgA level < 10 mg/dl in serum) and 11 normal volunteers with the same age and sex were compared. The ages of the people were between 3 and 18 years old and 5 girls and 6 boys were in each group. Their oral examination included DMFT (Decayed, Missed and Filled Teeth), periodontal condition, Plaque accumulation and oral mucosal lesions. Saliva immunoglobulin and secretary component levels were detected by enzyme- linked immunosorbent assay (ELISA) and serum immunoglobulin levels were detected by single radial immunodiffusion (SRID) methods. All of the IgA- deficient patients had the serum IgA level < 10 mg/dl and their immunoglobulin levels were normal.  of these patients didn't have SIgA and the rest of them had a little SIgA in their saliva(<  SIgA levels in sex and age matched normal group). IgA deficient patients showed no statistical significant difference about oral manifestations in comparison with normal group. It may be related to the increase of compensatory SIgM or assistance of other non- immunological defense factors in saliva, phagocytosis and cellular immunity. Thus IgA- deficiency cannot produce any oral manifestations as a criteria to diagnose it.

Background and Aim: Compared to the information about educational responsibilities, there is not much information about the research skills and activities of the academics in dental schools. The aim of this study was to evaluate the research performance of the academic staff of the dental schools and their educational needs to promote their research skills.

Materials and Methods: This cross-sectional study was done by mailing a questionnaire to all of the members of Iran dental faculties. The questionnaires contained personal information like age, sex, place of employment, educational records, and additional questions like the workshops previously attended, and interests to attend certain workshops. To evaluate the research performance of the academic staff, the number of accomplished researches, the articles published in known national and international journals, their skills in using internet, and the number of attended workshops about research methodology were included in the questionnaire. The completed questionnaires were gathered and evaluated by descriptive statistics.

Results: From the questionnaires gathered, 436 were eligible to be included in the study, which formed 58% of the academic staff of dental schools. The results showed that 7.4% of the staff had more than 10 researches conducted, 15% had 5-10, 49.9% had less than 5, and 27.7 had no researches done. Considering the articles published in known national journals, 28.2% had no papers, 51.8% had 1-5 papers, and 20% had more than 5 papers. Regarding the number of articles published in known international journals, 77.5% had no papers, and 20.2% had 1-3, and 2.3% and more than 3 papers. The "preliminary research methods" workshop had the highest percent of participation (71.6%), and "Stata acquaintance" workshop had the least (0.7%). The participants were mainly interested to participate in three workshops, "English scientific writing" (26.3%), "principles of scientific writing" (17.5%), and preparing research proposals" (16.2%), respectively.

Conclusion: We concluded that the research skills and performance of the academic staff, though improved in the recent years, is still unsatisfying. In order to promote it, it is recommended to organize workshops about "research methodology", "scientific writing" and "preparing of proposals"

Background and Aim: Qigong is a type of Chinese psychosomatic exercise that integrates meditation, slow physical movements, and breathing. Numerous physical and mental benefits have been classically ascribed to qigong. On the other hand, unstimulated saliva is thought to play an important role in oral immunity, enamel stability and moisturizing the oral mucous membrane. Impaired salivary secretion leads to dental caries, mucosal deterioration and mouth dryness. The aim of the present study was to analyze the effect of a qigong program on various parameters of saliva such as quantity of unstimulated saliva, pH and SIgA.

Materials and Methods: Twenty three subjects participated in this clinical trial study. The experimental subjects underwent a qigong training program, conducted by a qualified instructor. The program consisted of half an hour daily practice for 6 months (spring and winter). Saliva was collected in two periods: once during the spring before the experiment commencement and the second, in the following spring. During each period saliva collection was done on tuesday of each week. pH and quantity of salvia measurements were taken simultaneously. SIgA measurements were also taken based on the values obtained in the last phase of the experiment at the end of each spring. The results were analyzed using paired sample T test, one way repeated measure and Bon Ferroni multiple comparison. P<0.05 was the level of significance. Results: Based on our findings, the change in the amount of unstimulated salvia as well as SIgA was statistically significant (P<0.001) however, there was no significant difference in pH values before and after experiment.

Conclusion: These findings demonstrate that after 6 months of practicing qigong, significant changes in amount of unstimulated saliva and SIgA occurred in participants. The authors suggest that qigong may be a beneficial adjunctive treatment that enhances amount of unstimulated saliva and SIgA.

Background and Aim: Low birth weight is a significant public health issue. Recent studies have suggested periodontal diseases as risk factor for preterm labor. The aim of this study was to assess the relation between gingival health and preterm labor in a sample of Iranian female population.
Materials and Methods: In this cross sectional study, 201 pregnant women without any systemic diseases or other risk factors like psychotic conditions were selected. Ninety-nine of them had term labor (infant≥37 weeks) and 102 had preterm labor (infant<37 weeks). Bleeding index, pocket depth and debris index were measured. Data were analyzed by Chi-square and Mann-Whitney tests with p<0.05 as the level of significance.
Results: Bleeding index, probing depth and debris index showed statistically significant differences between preterm and term labor mothers (P<0.001).
Conclusion: According to the findings of this study, there is a significant relationship between gingival health and duration of pregnancy. Consequently, periodontal diseases could be risk factor for preterm labor. Oral hygiene is strongly recommended to be included in pregnancy health programs.

Background and Aim: Incomplete root development caused by trauma ,caries, or pulpal pathosis requires special attention and treatment . Although calcium hydroxide apexification has been used successfully for years but it requires patient cooperation and multiple appointments . Single visit apexification with MTA has been used in recent years. The purpose of this study was to compare bacterial microleakage of two types of MTA (Made in Iran and Brazil) applied as apical barrier in open apex teeth.

Materials and Methods: 48 single root teeth were used in this experimental in vitro study. Teeth apices were prepared as open apex teeth. For canal obturation the 4mm of root end was filled with 2 types of MTA (white Iranian MTA salami co. Iran and Angelus MTA Angelus Brazil) from coronal access. Teeth were mounted in self-cured acryl and put in BHI microbial culture. A suspension of Staphylococcus epidermidis was injected from coronal area into the root canals.The teeth were incubated and examined every 24 hours for microbial microleakage, indicated as turbidity in culture. Data were analyzed using Fisher exact test with p<0.05 as the level of significance.

Results: Microleakage appeared after 15 days in all Iranian and after 17 days in Angelus MTA samples.There was no significant difference between microleakage of two types of MTA (P = 0.48).

Conclusion: Based on the results of this study, there was no significant difference between microleakage of Iranian and Angelus MTA. If further studies confirm other physical, chemical, biological and sealing properties of Iranian MTA, it could be recommended for clinical application

Background and Aim: Sealing the root canal system is of great importance in endodontic treatment especially in infected teeth. Several materials have been introduced for this purpose. The aim of the present study was to evaluate the sealing ability of MTA as an orthograde root filling material and compare it with laterally condensed gutta-percha with sealer.

Materials and Methods: Thirty-six extracted human maxillary central and canine teeth were used in this experimental study. After preparation and surface disinfection with 1% NaOCl solution, the crowns of the teeth were cut at cemento-enamel junction.Roots were randomly divided into four groups: two experimental groups  of 15 roots each (gutta-percha with AH26 sealer and MTA) and two control groups of 3 roots each (positive and negative). After root canal preparation and filling, the sealing ability of each technique was assessed by immersion in 1% methylene blue dye for 72 hours. Then the teeth were cleared and the extent of dye penetration was measured with a stereomicroscope. Data were analyzed by T-test with P<0.05 as the level of significance.

Results: The results showed that the mean microleakage was 1.1mm (SD=2.1) in the gutta percha group and 3.4mm (SD= 2.1) in the MTA group.This difference was statistically significant (P=0.013).

Conclusion: Based on the results of this study, canal obturation with gutta-percha and AH26 sealer may provide a better apical seal compared with MTA. However, further studies on microbial leakage are needed for more precise evaluation of the sealing ability of MTA.

Background and Aim: Black staining after taking iron drops on the primary teeth is always concern of parents. There is not an exact explanation for the mechanism of iron black staining. The purpose of this study was to compare tooth discolorations, atomic absorption and structural changes of primary teeth enamel caused by two kinds of iron drops[ Kharazmi(Iran) and Fer-in-sol(USA)].

Materials and Methods: In this ex-vivo study, 93 sound primary teeth in normal color range were divided into five groups. Two groups of samples were immersed into the Artificial Caries Challenge(ACC) for two weeks before getting exposured to iron drops: Group 1 Control(NS): sound enamel teeth which were kept in Normal Saline environment(NS)(13teeth). Group 2 (NS-KH): NS, kharazmi iron drop (20 teeth). Group 3 (ACC-KH): ACC, Kharazmi iron drop (20teeth). Group 4 (NS-F-in-S): NS, Fer-in-Sol iron drop (20teeth). Group 5 (ACC-F-in-S): ACC, Fer-in-Sol iron drop. Visual tooth discolorations were determined by a specialist in operative dentistry who was not aware of experimental groups. The iron concentration was measured by ICP system (Vista-pro, Australia) and the structural changes were studied by SEM (Philips, Netherland). The data of discoloration were studied with Kruskal-Wallis test and multiple comparison using Bonferroni type test, and with the data of atomic absorption were studied with oneway ANOVA test and Tukey HSD test.

Results: The discoloration in the teeth immersed into the ACC (ACC-KH, ACC-F-in-S) was more severe than the sound enamel surface (NS-KH, NS-F-IN-S) (p<0.001) and Kharazmi iron drop caused more discoloration in the teeth immersed into the ACC (p=0.018). The teeth immersed into the ACC, absorbed more iron than the sound enamel surface (p<0.001) and also the teeth immersed into the ACC absorbed more Kharazmi iron drop (p<0.001). In the Scanning Electron Microscopy study, at low magnification in the sound teeth the perikymata was arranged regular. At low magnification in the teeth immersed into the ACC, many fractures were observed. The fractures in group 3(ACC-KH) were more and deeper.

Conclusion: Being immersed into the ACC, caused more iron absorption, severe discoloration and structural changes in the enamel of primary teeth. Such changes were more distinct in the teeth exposed to Kharazmi iron drop than the teeth exposed to Fer-in-Sol iron drop.

Background and Aim: Dental pulp calcification may have the same pathogenesis as vascular calcifications. Pulp stones are calcified mass, which are commonly observed in usual dental radiographs. The purpose of this study was to evaluate the relationship between pulp stones and ischemic CVD.

Materials and Methods: This was a cross-sectional descriptive-analytic study on 20-25-year-old patients who had at least 8 intact teeth and were referred to Afshar hospital for cardiovascular examinations. Relationship between vascular stenosis and dental pulp stone was explored.

Results: Sixty one patients who had undergone angiography were studied. They included 32 male (52.5%) and 29 female (47.5%). 38 patients had at least one stenotic vessel (from one to three vessels) and the others (37.7%) showed normal angiographic findings. 73.8% (31 cases) of the patients with dental pulp stones suffered from coronary narrowing where as only 36.8% (7 cases) of the patients without dental pulp stones showed coronary vessels narrowing. Pulp stones were mostly seen in first and second Molar teeth.

Conclusion: According to the results, we can state that oral and maxillofacial radiology is helpful in screening of cardiovascular diseases.

Background and Aims: The objective of the present study was to investigate knowledge and attitude of senior dental students towards HIV/AIDS. Its result could help in promotion of education.

Materials and Methods: This educational research was carried out in two state dental schools in Tehran. The senior dental students in Tehran and Shaheed Beheshti dental schools were asked to fill in a self-administered questionnaire regarding their age, gender, parents' job, knowledge and attitudes towards treatment of patients with HIV/AIDS in Autumn semester 2007. Fifty five dental students (83%) including 27% male and 73% female in Shaheed Beheshti and fifty five dental students (85%) including 34% male and 66% female in Tehran dental schools were participated. The score for knowledge and attitude of the students were calculated separately. The data were analyzed using Independent sample t-test.

Results: The mean percentage of knowledge and attitude scores were 76.5% (at rang 1-3) and 50% (at range 1-5), respectively. Nearly all of the students believed that all patients should be considered as HIV positive in dental practice, while 49% preferred to refer HIV positive patients. Knowledge and attitude of students were not significantly associated with the gender and knowing HIV positive person (P>0.05).

Conclusion: There is a need to improve knowledge and attitudes of dental students towards HIV/AIDS. It is suggested to emphasize on this subject in dental schools curriculum in Iran.

  Background and Aims: Along with the advances in dental materials and invention of new techniques for ceramic producion, the demand for the beauty and matching restoration’s color with patient’s natural teeth is growing. Nowadays, zirconia systems are the focus of attention. Despite their strength, one of the problems with such systems is the high opacity and failing to provide the favored color. Considering few studies about the influence of shading on Zirconia, the purpose of this in vitro study was to evaluate the effect of different shading of zirconia-based ceramics on the biaxial flexural strength .

  Materials and Methods: In this in vitro experimental study, Rainbow (Dentium, Korea) zirconia-based ceramics (the diameter of 15mm and 1mm in thick) were divided into four groups of 10 specimens. According to Vita shade guide system and manufacturer’s time recommendations (3 seconds), three groups of disc specimens were shaded to A3, B3 and D3 colors and other ten specimens remained uncolored as control group. The biaxial flexural strength test of discs was evaluated and the elements’ composition of colors was detected by Energy Dispersiue X-ray Microanalysisd (EDX). Finally, data were analyzed using one-way ANOVA and Post-hoc tests.

  Results: The biaxial flexural strength in non colored specimens, A3 shaded discs, B3 shaded, and D3 shaded specimens were determined 1061.93, 819.16, 1100.10, and 825.48 MPa respectively which was statistically significant among groups (P<0.001). The statistical analysis revealed that the highest strength in B3 and non colored groups which were significantly higher than A3 and D3. EDX analysis showed significant differences among different colored compositions.

  Conclusion: The biaxial flexural strength of zirconia cores are affected by shading and the specific selected color.

  Background and Aims: Different adhesives with different solvents may have different solvent evaporation rates. The purpose of this study was to evaluate the solvent evaporation in the self etch and total etch adhesive in different air drying times.

  Materials and Methods: Five adhesives were used in this study: Excite, Prime & Bond NT, UNO, Single Bond, SE Bond Primer. Twelve drops of each adhesive were used for each period of air drying (5, 15, 30 sec). The percentage of mass loss was measured during each test. Data were analized using two-way ANOVA and Tukey.

  Results: Acetone base adhesives showed more loss of mass than other adhesives (P<0.01). P&B NT showed more loss of mass than other adhesives in all air drying times (P<0.01). Adhesives showed different evaporation rates in different air times (P<0.01).

  Conclusion: Adhesives with acetone/water or alcohol/water solvent shows more stable behavior in comparison with adhesives containing pure aqueous solvents.