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Showing 109 results for Mohammad

E. Yasini , N. Mohammadi ,
Volume 12, Issue 3 (10 1999)
Abstract

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.


M. : Pak Nejad , Y. Soleimani-E-Shayesteh , Z. Mohammad Zadeh ,
Volume 13, Issue 3 (9 2000)
Abstract

Guided Tissue Regeneration (GTR) is the most recent and common method for regeneration of class II forcation molars. However, it requires membrane, which seems expensive for most of the patients. In order to overcome this problem, Coronally Position Flap (CPF) procedure may be applied which arresting the epithelial cell down growth, follow the same aim. This study is aimed to compare GTR technique utilizing bioresorable collagen membrane and CPF utilizing citric acid. Nine patients with grade II forcation defects were selected. Defects were bilateral that randomly assigned into two groups: GTR and CPF groups. Measurements recorded at baseline and after surgery (6 months). Paired-T test was performed on these data. The following results were obtained after 6 months: In both groups significant reduction in probing pocket depth were measured in GTR and CPF groups, 1.55 Ind 1.88 mm, respectively. Also, open vertical probing depth: 0.33, 1.11 mm. Reduction in forcation weight in both groups was 0.22 mm. Bone fill was observed in 0.33% and 51% of defects. No recession was observed in GTR group, in CPF was 0.11 mm. Loss of attached gingiva was 0.34 and 0.78 mm, respectively. No significant difference was found between clinical parameters except OHPD. Comparison of means at the day (0 and 180) in each group showed the success for regeneration of forca. Considering the results, it can be concluded that CPF may substitute for GTR technique.


M. Ghavam , M. Poorhaghighi , M. Mohammadi ,
Volume 13, Issue 3 (9 2000)
Abstract

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.


Ar. Talaeipour , Gh. Mohammadian , D.  ghoudarzi ,
Volume 14, Issue 2 (9 2001)
Abstract

Osteodystrophy is one of the most common complications at the last stage of renal disease,which cause low bone mineral density (BMD) and skeletal deformities in patients. In this study evaluation of renal osteodystrophy was evaluated through BMD measurement of 45 under dialysis and 78 healthy persons by intra-oral digital radiography (RVG). Results Showed that:1- The average of BMD in hemodialysis patients was indeed lower than normal population (P^O.OOO).2- The mean of BMD of females was lower than males (P=0.021).3- There was no correlation between and BMD (P=0.560).4- Age and BMD had no significant relationship (P=0.648).5- There was negative correlation between alkaline and BMD therefore ALP is a useful predictive factor forBMD(P=0.002).
Z. Pourpak , M. Shahrabi , J. Nikfarjam , M. Moazeni , L. Nikfarjam , A. Aghamohammadi ,
Volume 14, Issue 3 (9 2001)
Abstract

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.


E. Yasini , N Mohammadi ,
Volume 14, Issue 4 (10 2002)
Abstract

Posterior composite restorations, due to polymerization contraction, result in microleakage. Different methods have presented to reduce this phenomena. The aim of this study is to evaluate the effects of flowable and condensable composites to reduce microleakage. Seventy extracted human teeth were prepared with proximal class II cavities with gingival margin 1 mm below CEJ. The teeth randomly were divided into 7 groups. Groups I & II were restored with a dentin bonding (DB) agent plus a Prodigy condensable (Kerr Co.) composite, placing incremental or bulky, respectively.. In groups IK IV, V a dentin bonding agent was applied and then cavities were restored with Tetric flow composite resin as a base plus either a hybrid composite (Tetric ceram, Vivadent Co.) or a Prodigy condensable composite (Cond), placing bulky or incremental. Groups VI and VII were restored with a resin modified glass ionomer (GI) (Fuji II Lc Co.) as a base plus either Prodigy condensable or Tetric ceram. Restorations were polished, thermocycled, and immersed in 0.3% basic fushin. After that samples were sectioned and studied under a stereomicroscope to evaluate dye penetration. Results showed that all restorations showed some degree of microleakage and according to kruskall- wallis statistical analysis, there were not any significant differences between all groups (P-0.051). Then fore pair comparison, between groups. Mann-Whitney analysis was used and no statistical difference was observed. However. Gh DB- Tetric group showed the least microleakage and DB+ Cond (bulk) the most one. Due to lack of an" statistical difference among different materials methods, it is concluded that no method or restorative material have been able to eliminate microleakage in margins completely yet, and using a flowable composite resin, in place of resin modified glass ionomer or using a condensable composite, instead of conventional In brid composites, do not have any effect
N. Takzaree , K.  yarmohammadi , Ar. Takzaree , H.  semiyari. , M. Akbari ,
Volume 14, Issue 4 (10 2002)
Abstract

Pain reduction and surgical wound healing enhancement have several advantages. Wound healing is a complex and organized phenomenon. During this phenomenon, definite and harmonized processes such as: reconstruction, immigration parenchyma and connective tissue cells proliferation and re-construction of gingival connective tissue take place. Studies show that lower power laser (He-Ne) can induce different biological changes in ceils through biochemical mechanisms. Considering the therapeutic effects of (He-Ne) low power laser radiation on healing processes, cell proliferation, connective tissue fibers and finally the acceleration of gingival wound healing were studied. This study was done on 50 mature and healthy rats with the average weight of 250 to 300 grams, and 3 to 4 months old. After anesthesia, maxillary wounds, with the same size, were made in all samples and they were randomly divided into control and test groups. After surgery, rats of test group received laser radiation with the value of 5 mJ/cm3 every day for a period of 5 days. And on the 5lh day, they were killed. Gingival biopsy was performed and histological study was done. The number of fibroblasts, collagens, endothelial ceils and blood vessels were counted. In test group, the granulation tissue was more active and the edema and inflammation were lesser than those of the control group. Data were analyzed by t-test method and PO.05 was significant. So, it is concluded that periodical radiation of (He-Ne) low power laser has an important role on surgical gingival wounds.
S. Mir Mohammad Rezaee , A. Taghavi Nia ,
Volume 15, Issue 2 (8 2002)
Abstract

Recently. Minalux alloy, a base metal free from Be, has been presented on the market while no special soldering has been recommended for it. On the other hand, based on the manufacturer's claim, this alloy is similar to Verabond2. The aim of this study was to investigate the tensile strength of Minalux and Verabond2, soldered by Verasolder. Twelve standard dambble shape samples, with the length of 18 mm and the diameter of 3mm, were prepared from each alloy. Six samples of each alloy were divided into two pieces with carboradom disk. Soldering gap distance was 0.3mm, measured by a special jig and they were soldered by Verasolder alloy. Six other samples, of both Iranian and foreign unsoldered alloys were considered as control group. Then samples were examined under tensile force and their tensile strength was recorded. Two- way variance analysis showed that the tensile strength of Minalux alloy and Verabond2 were not statistically significant (Verasoler 686, Minalux 723), but after soldering, such difference became significant (Minalux 308, Verabond2 432). Verabond2 showed higher tensile strength after soldering.
A. Monzavi , S. Mir Mohammad Rezaei , H. Bajelan ,
Volume 15, Issue 2 (8 2002)
Abstract

Waxes have a lot of applications in dentistry. Such materials are of thermoplastic type that undergoes deformation in different temperatures. Two important properties of base plate waxes are flow and their coefficient of linear thermal expansion. Recently, different institutions, inside the country, produce dentistry waxes, while they have not been standardized. Consequently, consumers' dissatisfaction are observed. In this research, the two above- mentioned factors were compared between three kinds of Iranian waxes with Cavex that is foreign production, based on test number 24 of ADA. To measure the flow rate in the temperatures of 23, 37 and 45°c, Wilcoxon statistical analysis was used. The results showed that in 23°c, the flow rate of Cavex and Azardent waxes met ADA standards however, it was not true for two others types. In 37°c, the flow of none of the waxes was standardized and in 45°c their flow was acceptable, moreover, thermal expansion coefficient, for Cavex and Azardent types, was based on ADA standard.
S. Nokar , S. Moradian , M. Mohammad Zade ,
Volume 16, Issue 4 (9 2004)
Abstract

Statement of Problem: Color matching and accurate shade selection are the challenging problems common to restorative dentistry. In ceramometal restorations, the type of substructure alloy affects the final color of bonded porcelain. Nickel- chromium alloy is the most commonly used one that its Iranian product, namely Minalux, is similar to Verabond2.
Purpose: The aim of this study was to assess and compare various color dimensions resulting from Minalux and Verabond2 alloys.
Materials and Methods: Nine disks, approximately 16 mm in diameter and 0.5 mm thickness, were cast from each alloy. Then, porcelain Vita VMK68 A2 was baked onto the entire test disks, following the manufacturer's instruction. Color samples, at the same time and under the same conditions, was measured by Data color spectrophotometer in CIE Lab System and Munsel system under four light sources (A, C, D65 and TL81). Then MATLAB TOOL BOX Statistic 5.2 was used to determine mean and bilateral variance analysis.

Results: It was indicated that the F value on hue, value and chroma was less than of the table value stated with 99% coefficient confidence, confirming Ho theory. In other words, there were not any significant differences between ceramometal disks made of Minalux and Verabond2 in the three dimensions of color.
Conclusion: Having desirable physical, mechanical and biological properties, Verabond2 can be replaced by Minalux alloy.


Ma. Behnaz , F.   Behnaz , M. Mohammadzadeh ,
Volume 17, Issue 1 (7 2004)
Abstract

Statement of Problem: Hepatitis C is a relatively common infection which can be transmitted through accidental inoculation consequently dentists are highly at the risk of exposure to this virus.
Purpose: The aim of this study was to determine prevalence of Hepatitis C among the dentists of Yazd and to evaluate their knowledge about the existing ways for the transmission and prevention of this infection.
Materials and Methods: In this descriptive- analytic study which was performed periodically (2002), the sera of all dentists practicing in Yazd were tested (104 samples) in the laboratory of Yazd blood transfusion organization initially by 1st generation of Elisa for Anti HCV followed by Riba on positive samples to confirm the results. Meanwhile a questionnaire assessing their knowledge about hepatitis was completed the by the dentists. Data were analyzed by ANOVA and t test.
Results: None of the one hundred and four samples of sera were positive for Anti HCV. Mean score of their knowledge was 14.80 (of 20). The knowledge of 92.1% of them was at moderate to high level. No significant difference was observed between Yazd's dentists knowledge about hepatitis C in different age, gender and length of professional experience groups.
Conclusion: According to this study, the absence of HCV among the dentists of Yazd is mainly attributed to the low prevalence of HCV infection among general population, though it can also be an indicative of the knowledge and excellent performance of the dentists to prevent the transmission of infection through blood and saliva.
F. Ezoddini Ardakani , D. Goodarzi Pour , M. Soltani Mohammadabady , ,
Volume 18, Issue 3 (11 2005)
Abstract

Background and Aim: Proper shaping and cleaning of the root canal system is one of the most important aspects of endodontic treatment. To estimate the canal length before instrumentation in endodontic treatment, traditionally, conventional radiographic techniques and recently Direct Digital Radiography (DDR) are applied. The application of computer technology to radiography has allowed less exposure time, image acquisition, manipulation, storage, retrieval, and transmission to remote sites in a digital format, elimination of wet processing and considerable reduction in the time lapse between image acquisition and display. The purpose of this study was to compare the accuracy of DDR versus conventional radiography in estimating endodontic file lengths of curved canals in first mandibular molars.

Materials and Methods: In this test evaluation study, fourty extracted human first mandibular molars with root curvature were selected.Samples were divided into two groups: With root curvature less than 25 and more than 25. Samples were mounted in plaster blocks and canal lengths were estimated by using DDR and conventional radiographs. Regression analysis and correlation coefficient were used to calculate statistical differences between the groups with P<0.05 as the limit of significance.

Results: Conventional radiography was more precise in canals with less than 25 degrees curvature (P=0.160). While, DDR was more precise for canals with curvature more than 25 degrees (P=0.605). However, these differences were not statistically significant.

Conclusion: The image quality of DDR system has improved to the point that it can now be used for estimating canal lengths, even for curved canals, with accuracy comparable to that of conventional radiography.


A. Ebadifar , Mr. Mohammadi , N. Valaee ,
Volume 18, Issue 4 (5 2006)
Abstract

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"


S. Bayat Movahed , Y. Soleymani Shayesteh , H. Mehrizi , Sh. Rezayi , M. Mohammadi , K. Bamdad Mehrabani , M. Koohkan , B. Golestan ,
Volume 20, Issue 1 (4 2007)
Abstract

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.


Sh. Zadeh Modarres , B. Amooian , S. Bayat Movahed , M. Mohammadi , L. Sheikholeslam , F. Sheikholeslam ,
Volume 20, Issue 1 (4 2007)
Abstract

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.


M. Tabrizizadeh , H. Zandi , Z. Mohammadi , A. Molana ,
Volume 20, Issue 3 (4 2007)
Abstract

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


H. Siadat, A. Mirfazaelian , M. Alikhasi , M. Mohammad Alizadeh ,
Volume 20, Issue 4 (5 2008)
Abstract

Background and Aim: An important criterion for success assessment of implant-supported prostheses is marginal fit. Vertical and horizontal discrepancy can result in loosening of the prosthetic screw, crestal bone resorption, peri-implantitis and loss of osseointegration. Despite careful attention to waxing, investing, and casting, marginal discrepancies are inevitable. The aim of this study was to evaluate the marginal gap and overhang in three casting methods with two different alloys in ITI implants.

Materials and Methods: In this experimental in vitro study 48 analog abutments were randomly divided into six groups as follows: 1) burn out cap + BegoStar, 2) impression cap + BegoStar, 3) conventional wax up + BegoStar, 4) burn out cap + Verabond2, 5) impression cap + Verabond2, 6) conventional wax up + Verabond2. Waxing was done in 0.7 mm thickness verified by a digital gauge and a putty index was made for all groups. Reamer was used for correction of the finish line after casting in all groups. Castings were seated on analog abutments and embedded in acrylic resin. Specimens were sectioned by isomet instrument and polished and cleaned by ultrasonic cleaner for 10 min. The marginal gap and overextended margins of castings were examined under a  Scanning Electron Microscope (SEM) (X200). The mean gap and margin overextension were calculated for each group. Data were analyzed by multivariate analysis and Bonferroni post-hoc test with p<0.05 as the level of significance.

Results: No significant difference in gap size was observed among the three casting methods with two alloys (P=0.056). The marginal gap was not different in the studied casting methods (P=0.092). Gold alloy crowns showed lower marginal gaps compared to base metal alloy crowns (P<0.001). No significant difference in overhang size was observed among casting methods with two alloys (P=0.093). Base metal alloy crowns showed less overhang compared to gold alloy crowns (P<0.001). There was a significant correlation between overhang and use of impression cap in base metal alloys (P<0.001).

Conclusion: Based on the results of this study, vertical discrepancy of frameworks made with gold alloy were less than those made with base metal alloy. Base metal alloy demonstrated less overhang. Conventional wax up or using burn out caps produced less horizontal discrepancy.


M. Tabrizizadeh , Z. Mohammadi , Mj. Barzegar Bafruyi ,
Volume 20, Issue 4 (5 2008)
Abstract

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.


M. Mehran, M. Mohammadi Bassir, S. Jafari ,
Volume 21, Issue 4 (19 2009)
Abstract

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.


F. Ezoddini Ardekani, Z. Mohammadi, Z. Hashemian, M. Sadrbafghi, A. Hedayati, Mj. Rahmani Baghemalek,
Volume 22, Issue 1 (11 2009)
Abstract

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.



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