Journal of Isfahan Dental School
Year:2011 | Volume:6 | Issue:4|Papers Count:33

Introduction: Pain control is of utmost importance in all dentistry fields. Anesthetic injection is perhaps the most difficult part of treatment in children. The most common anesthesia technique in the mandible is the inferior alveolar nerve block. As the block injection has a lasting anesthetic effect in children and also might cause traumatic injuries to soft tissues a different injection technique is needed. This study compared infiltration and block techniques for pain control during pulpotomy in the primary first mandibular molars.Materials and Methods: In this clinical study forty 5-8 year-old children were chosen. The subjects needed bilateral pulpotomy of primary mandibular first molars. This study was conducted based on a cross-over design. The patients were randomly divided into two groups. The patients in group A received an infiltration injection on the right side and a block injection on the left during the first and second sessions, respectively. The patients in group B received a block injection on the right side and an infiltration injection on the left during the first and second sessions, respectively. The patient pain was recorded at the moment of injection and on pulp exposure based on SEM (Sound Eye Molar) scale. Data was analyzed by Mann-Whitney U and Wilcoxon signed-rank tests. Statistical significance was defined at a=0.05.Results: The results showed that at the moment of injection the SEM in the infiltration technique was significantly lower than that in the block technique, which demonstrates that the child can better tolerate the pain in the infiltration injection (p value<0.001). However, the two techniques did not show significant differences in pulpal anesthesia based on the SEM scale.Conclusion: It seems the infiltration technique is superior to the block technique in controlling pain during pulpotomy in the mandibular primary first molars in 5-8 year-old children.

Introduction: There is a high demand for tooth-colored restorations in pediatric dentistry. Since etch-and-rinse adhesive systems are time-consuming, there is a tendency to replace them with simplified adhesive systems. This study compared microleakage of class V composite resin restorations in primary teeth restored using simplified adhesive systems.Materials and Methods: In this in vitro study standard class V cavities were prepared in 60 primary canines with incisal margins in enamel and gingival margins in dentin. The samples were randomly divided into 4 groups and restored as follows: Group 1: Opti Bond Solo Plus (OBP); Group 2: Clearfil SE Bond (SEB); Group 3: Clearfil S3 Bond (S3B); Group 4: Xeno IV (XeIV). The cavities were filled with Filtek Z250 composite resin and observed under a stereomicroscope at × 32 for microleakage scoring. The results were analyzed with Kruskal-Wallis test followed by Mann-Whitney and Wilcoxon Signed Rank tests using SPSS software.Results: The results showed significant differences between groups 1 and 4 and group 3 in enamel leakage (p value=0.005). There was also a significant difference between group 1 and groups 2 and 4 in dentinal leakage (p value=0.001). The test showed that enamel leakage in groups 1 and 4 was significantly lower than dentinal leakage in these groups.Conclusion: The strong acidic adhesives in groups 1 and 4 were more effective in enamel leakage prevention. The mild self-etching adhesive in group 3 was effective in enamel and was the best in dentin leakage prevention.

Introduction: Various root canal filling materials have been introduced in endodontic therapy, of which gutta-percha is the most common. Sealer is an essential component for obturation with guttapercha.The aim of this study was to assess sealing ability of three sealers (pure ZOE, Roth 801, and AH26) using bacterial penetration method in an innovative system of flowing saliva in the presence or absence of the smear layer.Materials and Methods: The canals were prepared in 188 extracted human teeth. In half of the samples the smear layer was removed using 17% EDTA (ethylenediaminetetraacetic acid) and 5.25% sodium hypochlorite. The specimens were randomly divided into three subgroups. The experimental groups were obturated with a single-cone of gutta-percha and one of the abovementioned sealers (half without and half with the smear layer). Then the teeth were placed in vials containing sterile TSB (Tripticase Soy Broth) culture media. All the samples were exposed to artificial flowing saliva with bacterial suspensions for 90 days. The turbidity of the culture media was checked and recorded daily. Data were analyzed using Factorial Analysis Variance and ANOVA.Results: The longest and shortest mean periods of culture media turbidity were seen in the AH26 group without the smear layer (67.85 days) and in the pure ZOE sealer group with the smear layer (31.3 days), respectively.Conclusion: The results showed that removal of the smear layer enhances the sealing ability of sealers, especially in resin sealers such as AH26.

Introduction: As dentin bond strength of the materials containing resin is reduced after bleaching, a delay in bonding for at least one week after bleaching is recommended. The aim of this study was to investigate the neutralizing effect of an antioxidizing agent on the shear bond strength (sbs) of bleached dentin and compare it with a delay of one week before bonding of composite resin (CR) and resin-modified glass-ionomer (RMGI).Materials and Methods: Exposed dentin surfaces of 96 sound human molars were divided into eight groups. Buccal dentin surfaces of the specimens in group 1 and 5 were consecutively bonded with CR and RMGI cylinders. The specimens in other groups were bleached for six hours a day for five consecutive days. For the specimens in groups 2 and 6, bonding of CR and RMGI was performed immediately after bleaching, respectively.The specimens in groups 3 and 7 were immersed in distilled water for one week and then CR and RMGI were bonded. For the specimens in groups 4 and 8, 10% sodium ascorbate gel was applied and then CR and RMGI were bonded, respectively. Shear bond strengths of the specimens were measured. Data was analyzed by ANOVA and Tukey test (a=0.05).Results: The mean sbs values for groups 1 to 5, 7, and 8 in MPa were 17.055±2.954, 8.19±0.941, 16.406±1.508, 15.640±3.073, 8.893±0.620, 8.162±0.975, 7.584±0.939, respectively. There were significant differences between the study groups. The specimens of group 6 had pretest failure.Conclusion: Bleaching led to a significant decrease in sbs of CR to dentin immediately after bleaching, and RMGI did not bond in this situation. A delay of one week before bonding and application of sodium ascorbate gel significantly increased the sbs of the evaluated materials to bleached dentin. In the composite groups the delayed subgroup had significantly higher sbs than the sodium ascorbate subgroup. In glass-ionomer groups there were no significant differences in sbs values.

Introduction: Lichen planus is a relatively common, chronic mucocutaneous disease with the risk of malignancy. In recent years, there have been increases in the prevalence of oral lichen planus (OLP) and it looks there are some changes in the epidemiologic pattern of this lesion. Despite the existence of different studies about the changes in OLP lesion epidemiology, this study aimed to investigate epidemiologic changes of oral lichen planus in patients referred to the Oral Pathology Department of Isfahan Dental School (1988-2008).Materials and Methods: In this descriptive study, archives of the Oral Pathology Department from 1988-2008 was reviewed. Sex, age, location and type of lesion and the referral year were recorded.Data were analyzed by one-way ANOVA with SPSS11.5 statistical software.Results: A total of 6509 patients had been referred to the Oral Pathology Department, with 238 (3.65%) of cases diagnosed with OLP, 154 (64.7%) of the cases were females. The mean age of OLP patient was 44.8±12.7 years. Buccal mucosa was most frequently involved (68.1%).Conclusion: An increase in the number of patients and decrease in mean age of the patients with OLP was noted, which might be attributed to population growth and an increase in the number of cases referring to dental practitioners, or more accurate diagnosis in recent years. Therefore, regular follow-up programs are recommended for the diagnosis and treatment of high risk groups.

Introduction: Shear bond strength is one of the most important mechanical characteristics involved in clinical durability of tooth-colored restorations, which is directly related to polymerization shrinkage. This study evaluated the efficacy of two light-curing units (LED2 & QTH) and two types of dentin bonding agents (Excite & Clearfil SE bond) on composite resin shear bond strength to dentin.Materials and Methods: Forty caries-free sound human premolars were randomly divided into 4 groups of 10 after being disinfected with sodium hypochlorite. The occlusal surface of dentin in each specimen was exposed and flattened by a fissure bur, composite resin was bonded with Excite or Clearfil SE bonding agents and polymerized with QTH or LED2. Shear bond strength values of the specimens were tested in a Dartec universal testing machine. Data were analyzed by one-way ANOVA, two-way ANOVA and Dunkan test (a=0.05).Results: Maximum shear bond strength values were recorded in composite restorations bonded with Clearfil SE bonding agent and polymerized by LED2, minimum values were recorded in composites restorations bonded with Excite and polymerized by QTH. Statistical analysis showed statistically significant differences between the experimental groups (p value=0.03).Conclusion: Under the limitations of this study, it can be concluded that two curing systems of LED2 & QTH are equally effective on shear bond strength of different bonding agents, whereas Clearfil SE bonding agent produces higher shear bond strength than Excite total-etch regardless of the type of light-curing unit.

Introduction: Osteoporosis is an asymptomatic disease until it causes fracture. One of the most effective methods for its diagnosis is DEXA test. This test shows BMD and T-Score for selective parts. Osteoporosis also causes some alterations in jaws that are observed by dental practitioners. The aim of this study was to determine the relationship of MCW (Mandibular Cortical Width) with BMD and T-Score.Materials and Methods: In this analytic cross-sectional study 51 post-menopausal women who had undergone DEXA test from lumbar spine (L2-L4) and panoramic radiography were selected.The subjects were divided into 3 groups according to T-Score and WHO criteria: 1) Normal, 2) Osteopenic, 3) Osteoporotic. MCW was measured at mental foramen area on the panoramic radiographs and analyzed in relation to BMD and T-Score using ANOVA, Scheffe, Pearson’s correlation and regression tests.Results: The mean mandibular cortical widths in the normal, osteopenic and osteoporotic groups were 4.8 mm, 3.8 mm and 2.7 mm, respectively. Pearson's correlation coefficients between BMD and MCW, and T-Score and MCW were 0.896 and 0.903, respectively. Regression between BMD, T-Score and MCW was significant (p value<0.001).Conclusion: MCW mean differences between normal, osteopenic and osteoporotic women were significant (p value<0.001). MCW had a high correlation with BMD and T-Score (about 0.9).Based on the results of this study, dental practitioners might be the first person to suspect osteoporosis in post-menopausal women from panoramic radiographs and refer them to specialists.

Introduction: Cleft lip and palate are the most common congenital anomalies in the head and neck region, which are affected by environmental and genetic factors. The prevalence of these anomalies varies in different countries. There is no scientific report from the west of Iran. The aim of the present study was to determine its prevalence and related risk factors in infants born in Kermanshah hospitals during 2001-2008.Materials and Methods: In this descriptive study, 62823 infants born during 2001-2008 in Motazedi and Imam Reza hospitals in Kermanshah (a city in the west of Iran) were reviewed. A total of 98 cases with oral clefts were recorded. Data were analyzed by ANOVA and Chi-square test using SPSS12 statistical software.Results: Out of 62823 infants 98 cases had oral clefts (1.5 for 1000 birth), 59.1% of which were males, 38.8% had cleft lip and palate, 31.6% had cleft lip and 29.6% had cleft palate. A total of 51.4% of parents had familial marriage, 14.7% of mothers reported use of medications, 41% of mothers had A+ blood group, 37.2% of the newborns were the first baby of the family and 93.8% of mothers had not taken vitamin supplements. The mean age of mothers were 27 years and the highest number of clefts belonged to 21-30 year-old mothers.Conclusion: The prevalence of oral clefts and their types in Kermanshah are consistent with world reports but lower than the calculated average for Iran.

Introduction: Bonding orthodontic attachments to large amalgam restorations of posterior teeth is a challenge. The aim of this study was to evaluate and compare the shear bond strength (SBS) of orthodontic attachments bonded to amalgam with different chemical surface preparations.Materials and Methods: In this in vitro study 105 convex amalgam surface samples were subjected to aluminium oxide sandblasting. The amalgam sampless were randomly divided into three equal groups. In each group buccal tubes were bonded with Transbond Plus using Reliance Metal Primer (RMP), All Bond II (AB2), and Alloy Primer (AP). Thirty-five human teeth served as the controls to test buccal tube bonding to acid-etched enamel with Transbond Plus and Transbond XT. All the samples were stored in artificial saliva, after thermocycling for 1000 times, all the sampels were tested for SBS. Data were analysed with Kruskal-Wallis and Mann-Whitney tests.Results: There were statistically significant differences in SBS values between all the groups (p value<0.001). AB2 created the strongest bond to amalgam (6.75 MPa). However, there were no significant differences between SBS values achieved with AB2 and those in the control group (p value=0.455). No Significant differences were observed between AP and RMP (p value=0.051) but both had significant differences with the control group (p value<0.001).Conclusion: The results of the present study revealed that AB2 intermediate resin is useful for strong bonding of metal orthodontic attachments to dental amalgam.

Introduction: Wear resistance of artificial teeth has an important role in denture longevity. The purpose of this in vitro study was to evaluate wear resistance of four brands of artificial teeth.Materials and Methods: In this in vitro study four brands of artificial teeth, including Apple, Yaghoot, Glamour and Ivoclar were used. Ten maxillary first premolars were selected from each set and were fixed in autopolymerizing acrylic resin. Wear test was performed for 1000 and 2000 cycles. Heights of the teeth were measured under a light microscope before and after wear cycles.Data were analyzed by ANOVA and Duncan tests (a=0.05).Results: ANOVA showed that mean wear rate of the teeth in both 1000 and 2000 cycles had significant differences (p value<0.001). According to Duncan test, except for Apple and Yaghoot, other groups had significant differences with each other (p value2=0.314), (p value1=0.289).Conclusion: It was concluded from the results of the present study that wear rate of Ivoclar teeth was significantly lower than that in other groups. Glamour, Yaghoot and Apple teeth showed the highest rate of wear, respectively.

Introduction: Irsha is an Iranian sample of Listerine mouthwash. To date biologic effects of Irsha and Listerine have not been compared. This study compared the antimicrobial and cytotoxic effects of Listerine and Irsha mouthwashes.Materials and Methods: In this in vitro study, antimicrobial effects of 5 dilutions of Irsha and Listerine, on the 0.5 MacFarlnd concentrations of five bacterial strains (Streptococcus mutans, Streptococcus Sangius, Enterococcus Fecalis, Candida albicans and Escherichia coli) were assessed at different times. Each test was repeated three times, with distilled water as control. For cytotoxic effect, more than 100000 cells of KB (epithelial cell), J774.A1 (macrophage), Saos-2 (osteoblast) and MRF (fibroblast) were cultured and incubated for 72 hours in different dilutions of the two mouthwashes (0.5, 1, 5, 10%). After incubation, the cells were washed and stained with MTT for 45 minutes. The results were recorded with ELISA READER and analyzed with SPSS 18 software, using ANOVA, Tukey test and one-way ANOVA. Statistical significance was defined at p value<0.05.Results: The cytotoxic effects of various dilutions of Listerine and Irsha mouthwashes were not significantly different (p value>0.05). In terms of antimicrobial activity, in dilutions of 100% and 50% of Listerine none of the five bacterial strains grew. However, at the same dilutions (100% and 50%) of Irsha, only three strains did not grow.Conclusion: According to the results, antimicrobial activity of Listerine is probably better than Irsha, but cytotoxic effects of Listerine and Irsha mouthwashes were not different.

Introduction: Mean bar failure in overdenture-supported implant has been reported to be 3.97 percent, even this low failure rate is unacceptable for patients because of its cost compared with complete denture. The aim of this study was to assess stress distribution in different points of the bar of overdenture-supported implants by finite elements analysis.Materials and Methods: In this descriptive study, stress distribution on the bar of mandibular overdenture was evaluated by the finite elements analysis (FEA). Implants in two canine areas were connected to each other by one bar at the distance of 2 mm from the lining tissue of the edentulous ridge. Then the vertical force applied to the left first molar increased gradually from 0.5 to 50 N and stress distributions were recorded at different points of the bar.Results: By increasing the force up to 6.06 N, stress was uniformly distributed over the bar, but with greater force stress was focused on the border of the middle third and the force application third. This pattern of stress distribution continued parallel with an increase in the force.Conclusion: Failure is higher at the border area between the middle third of the bar and the third near the applied force due to maximum stress, therefore, reinforcement of the bar at this area is suggested.

Introduction: Complete root canal seal is one of the most important aims of root canal treatment.The aim of this study was to compare the sealing ability of three resin-based sealers (AH26, AH Plus Jet and TG Adseal) against microbial microleakage.Materials and Methods: In this in vitro study, 87 single-rooted extracted human teeth were decoronated maintaining a root length of 15 mm. Apical preparation and coronal flaring of the root canals were carried out up to #40 and #80 K-files, respectively, using the step-back technique. After cleaning and shaping, the teeth were randomly divided to 5 groups: Three experimental groups of 25 teeth, a positive control group of 3 teeth and a negative control group of 9 teeth. The experimental groups were obturated with gutta-percha and AH26 sealer, gutta-percha and AH Plus Jet sealer, and gutta-percha and TG Adseal sealer. The samples were evaluated daily for 90 days and the time of culture contamination with Enterococcus faecalis was registered in each case. The results were statistically analyzed by Kaplan-Meier, Chi-square and Mann-Whitney tests.Results: All the samples in the positive control group were infected after 24 hours. None of the negative control samples were infected after 90 days. Time of contamination between experimental groups showed no significant differences (p value=0.611).Conclusion: TG Adseal can be recommended for root canal therapy due to its sealability which is comparable to AH26 and AH Plus Jet root canal sealers and its appropriate cost.

Introduction: Garlic (Allium sativum) extract has an inhibitory effect on various pathogenic bacteria, viruses and fungi. The aim of the present study was to evaluate in vitro inhibitory effect of garlic extract on multi-drug-resistant (MDR) strains of Streptococcus mutans isolated from human carious teeth. Filtered sterilized aqueous extract of garlic was used in the present study.Materials and Methods: In this in vitro case-control study data was analyzed with Student’s t-test (a=0.05). From 105 extracted human carious teeth 92 strains of S mutans were isolated. Disk sensitivity tests and broth dilution methods were used to determine antibiotic sensitivity profile and inhibitory activity of garlic extract on S mutans.Results: Among 92 isolates of S mutans, 28 (30.4%) were MDR since they were resistant to four or more antibiotics. The highest and least resistance rates were observed for tetracycline (30.4%) and teichoplanin and vancomycin (0%), respectively, on the other hand, 22.8% and 23.9% of the isolates were resistant to penicillin and amoxicillin, respectively. Chlorhexidine minimum inhibitory concentration (MIC) for MDR and non-MDR S mutans varied from 2 to 16 mg/mL and from 0.25 to 1 mg/mL, respectively (p value<0.05). All the isolates, MDR and non-MDR, were sensitive to garlic extract with the MIC ranging from 4 to 32 mg/mL.Conclusion: Considering the data obtained from the present study, mouthwashes or toothpastes containing optimum concentrations of garlic extract can be used for the prevention of dental caries.

Introduction: It has been demonstrated that use of plasma rich in growth factors produces a dynamic surface on the implants, which accelerates the healing process. This study undertook a histologic and histomorphometric evaluation of the effect of platelet-rich growth factors (PRGF) on the amount of bone regeneration around dental implants.Materials and Methods: In this animal-intervention study, two systemically healthy Persian mixbreed dogs were selected. Three months after extraction of the dogs’ mandibular premolars on both sides, 12 implants were selected from the OIC system with a length of 10 mm and a diameter of 5 mm.Six implants were placed in the osteotomy cavities using growth factors and 6 others were placed in the osteotomy cavities without PRGF. After 12 weeks, all the implants were removed along with the surrounding bone using Trephine bur. The samples were evaluated under a light microscope subsequent to sectioning. Data were analyzed with t-test and Mann-Whitney test (a=0.05).Results: The results of the present study indicated that histologically, there was a significant increase in the amount of regenerated bone around the implants, moreover, thickness and maturity of bony trabeculae were not different in the samples containing PRGF in comparison with the control samples.Conclusion: According to the results, implant-bone interface integration rate around dental implants coated with PRGF was higher compared to the control group.

Introduction: Lichen planus is a chronic mucocutaneous disease with unknown etiology and pathogenesis. It is thought that immunological (humoral and cellular) disorders and genetic factors, such as HLA, are involved in its pathogenesis. This study evaluated and compared frequency distribution of HLA-DR1-7 antigens in various forms of oral lichen planus.Materials and methods: This retrospective case-control study was carried out on 66 lichen planus patients from May 2009 to August 2010. The subjects were evaluated in 6 groups of 11. After clinical and pathological confirmation of oral lichen planus, whole blood samples were obtained for evaluation of HLA-DR1-7 presence with PCR. Data was analyzed by chi-square, t-test, and Cochran and McNemar tests (a=0.05).Results: There was a significant difference in HLA-DR2 antigen frequency, with the highest and lowest frequencies in the bullous and plaque-like forms, respectively. HLA-DR3 antigen frequency was the highest in the papular and the lowest in the reticular and bullous forms and it appeared to have a significantly higher frequency in the plaque-like form compared to the reticular and bullous forms. HLA-DR4 antigen had the highest and lowest frequencies in the erosive and papular forms, with significantly higher frequencies in the reticular and erythematous forms compared to the papular form. HLA-DR7 antigen had the highest and lowest frequencies in the plaque and bullous forms, with significantly lower frequencies in the reticular, erythematous, and popular forms compared to the plaque-like form.Conclusion: Under the limitations of the present study it was concluded that the frequency of some HLA-DR antigens were significantly different in various OLP forms. The possible effect of these antigens on the incidence of some forms of OLP necessitates further studies on the subject.

Introduction: This study compared bone produced by tissue engineering from the adipose tissue stem cells with autogenous bone graft (ABG) in the repair of alveolar cleft model in the maxilla of dogs.Materials and Methods: In this experimental-interventional study, mesenchymal stem cells were isolated from four dog's subcutaneous fat tissue after detecting the markers by flow cytometry, then the cells were proliferated after cultivation. These cells were cultured in hydroxyapatite tricalcium phosphate scaffolds and placed in a special osteogenic environment. Accuracy of mesenchymal stem cell osteogenic induction was confirmed by RT-PCR. At first in 4 dogs, two teeth of the three incisors were removed on each side and a 15-mm-wide defect was produced on both sides from the alveolar crest to the nasal cavity floor. Nasal mucosa was sutured to the oral mucosa. To preserve the space, a stent was placed on each side. After 60 days, on one side the cleft was regenerated with osteogenic cells produced from osteogenic differentiation and with the autogenous bone obtained from dog's tibia on the other. Bone regeneration was assessed at 15- and 60-day intervals postoperatively with biopsy by histomorphometry. Data was analyzed with descriptive statistical tests and t-test (a=0.05).Results: Mean bone regeneration at 15- and 60-day intervals on the autograft and the stem cell sides were 45%, 95%, 5%, and 70%, respectively. Statistical analysis revealed significant differences in bone formation between the two autograft and stem cell groups at both intervals (p values of 0.004 and 0.001, respectively).Conclusion: Tissue engineering can be used as an alternative technique with clinical success and optimal bone formation in cases with limited access to autogenous bone or with possibility of significant morbidity at the site.

Introduction: Oral lichenoid reactions (OLR) are disorders which cannot be distinguished from oral lichen planus (OLP) by their clinical or histopathological features. In recent years both disorders have been considered T-cell mediated inflammatory diseases. The aim of this study was to gather more information to help better distinguish these two lesions.Method and Materials: In this descriptive-analytical study, blood samples were taken from 80 patients (59 females and 29 males) and sent to the laboratory for histopathological diagnosis based on WHO criteria. After separating the blood sera of the samples, the sera were evaluated by ELISA for the presence of ANA, anti-DNA, RF, and SMA auto-antibodies. Data was analyzed with SPSS using the chi-squared test and t-test (a=0.05).Results: The mean ages were 48.62 and 49.38 for OLP and OLR patients, respectively. There were no significant differences in ANA and RF blood levels (p value>0.05). Anti-DNA and SMA antibodies were not detected in the blood samples. No significant differences were noted in the blood levels of these antibodies (p value>0.05).Conclusion: According to the results of the present study, no significant differences were observed between the OLP and OLR patients in relation to the presence or absence of ANA, anti-DNA, RF, and SMA auto-antibodies in the blood samples.

Introduction: Dental caries is the most prevalent chronic disease all over the world and imposes heavy costs on people and health services each year. The present study was designed to evaluate the effect of DMFT, its related factors and dental education on the orodental health of dental students in Isfahan Faculty of Dentistry.Materials and methods: In this descriptive cross-sectional study all the dental students (n=202) in Isfahan Faculty of Dentistry were evaluated regarding DMFT and oral hygiene procedures they were engaged in. For DMFT index the subjects were clinically examined, to evaluate oral hygiene procedures which the students used questionnaires were used. Data was analyzed by Spearman correlation coefficient, t-test, and Kruskal-Wallis and Mann-Whitney tests using SPSS 11 software (a=0.05).Results: Mean DMFT index was 5.043, it was 5.54 and 5.33 in males and females, respectively, demonstrating no significant differences (p value<0.05). Mean DMFT index demonstrated no significant differences between students of different educational years (p value>0.05). Statistically significant differences were noted with the use of dental floss in students of different educational years, however, the results of the study showed that brushing frequency was not significantly different among the students (p value>0.05).Conclusion: Our results showed that it is necessary to raise awareness in oral hygiene and an emphasis on oral hygiene instructions is necessary.

Introduction: Discolored teeth can be treated by various techniques, including direct composite resin veneers, indirect porcelain veneers, ceramic crowns, and bleaching agents. The aim of this study was to evaluate the effect of at-home and in-office bleaching agents on the surface microhardness of one microhybrid (Point 4) and two nanofilled (Filtek Supreme and Premise) composite resins.Materials and methods: Opalescence PF with 20% carbamide peroxide and Opalescence Quick with 35% carbamide peroxide were used as at-home and in-office bleaching agents, respectively.Fifty samples from each composite resin, including Point 4 microhybrid, Premise and Filtek Supreme nanofilled composites resins were prepared and exposed to bleaching agents. For each composite resin the samples were randomly divided into five groups of 10 and designated as: control, two-week at-home, four-week at-home, one-time in-office and two-times in-office bleaching groups with two-week intervals. After the appropriate bleaching procedures on samples of each group, microhardness measurements were carried out on each sample. Data was analyzed using ANOVA and post hoc Tukey HSD test (p value<0.05).Results: There were significant differences in mean surface microhardness values of each composite resin type. No significant differences were observed in mean microhardness values of Point 4 between four-week at-home and one-time office, Filtek Supreme between two-week at-home and four-week at-home, and Premise between one-time in-office and two-time in-office bleaching groups.Conclusion: Under the limitations of the present study, it was concluded that the microhardness of three composite resins tested in the present study were affected by bleaching agents.

Introduction: Heart disease is a great health problem. The most important symptom of heart disease and atherosclerosis is chest pain. Pain might extend to the arms, neck and lower jaw. Patients with central atherosclerotic heart disease, who suffer from angina, may in rare occasions have recurrent pain in the lower jaw or a tooth. The aim of this study was to determine the correlation between mandibulofacial pain and ischemic heart disease.Materials and Methods: In this descriptive, cross-sectional study 210 subjects with ischemic heart disease (angina pectoris and myocardial infarction), whose disease had been confirmed by a cardiologist and had had the problem at most one month before the study (2009-2010) were evaluated. Clinical and radiographic evaluations were carried out to establish the synchronicity of myofacial pain with cardiac pain. Data was analyzed with chi-square test (a=0.05).Results: None of the subjects reported mandibulofacial pain as the only manifestation of ischemic heart attack, however, 24 subjects had mandibulofacial pain with symptoms and pain in other parts. Almost 58.6% of subjects were males and 41.1% were females, with a mean age of 56.74.Twenty-four subjects reported mandibulofacial pain during MI or angina attack, evaluation of the oral cavity and mandibulofacial region with radiographic and clinical examinations did not reveal any problems. Of 24 patients with mandibulofacial pain 17 were males and 7 were females.Conclusion: It is concluded that in case of mandibulofacial pain in the absence of dental problems the dental practitioner should suspect ischemic heart disease.

Introduction: Different techniques are used to treat open apices, including MTA plugs. Regarding MTA’s long setting time, which results in greater microleakage during the first hours after its placement and its difficult handling properties, the aim of this study was to evaluate microleakage of MTA plugs mixed with normal saline and egg white.Materials and Methods: Seventy extracted human single-rooted teeth were randomly divided into two groups of 30 and two positive and negative control groups of 5. In group 1, an MTA plug mixed with normal saline was placed in each canal. In group 2, albumin was mixed with MTA. In the positive control group, a #80 gutta-percha was placed inversely in each canal. In the negative control group, the canal was obturated with MTA and the access cavity was filled with sticky wax.Root surfaces, except for the apical 2 mm, were covered with 2 layers of nail varnish. All the teeth were placed in the bacterial leakage evaluation system and were sterilized with ethylene oxide gas.Then they were transferred to anti-serum vials containing BHI solution. A fresh solution of Enterococcus faecails was injected into the system every 3 days. The samples were evaluated daily for 90 days for turbidity was. Data was analyzed using Kaplan-Meier survival analysis (a=0.05).Results: Turbidity rates in groups 1 and 2 were 76.7% and 60%, respectively, with average turbidity times of 27.06 and 42.13 days. No significant differences were noted between the two groups (p value=0.151).Conclusion: There were no significant differences in microleakage between MTA plugs mixed with albumin and normal saline. The first combination can be used to improve the setting time and handling properties of MTA.

Introduction: Despite developments in implant-supported prosthetic procedures, there are still cases treated with tooth-supported cantilevered FPDs. The aim of this study was to review the indications of these restorations and various factors which affect their success and longevity.Materials and Methods: Pubmed search was carried out in Medline from 1950 to 2010 using the following key words for the purpose of the present review: fixed partial denture, denture design, biomechanics and cantilever. Electronic search was supplemented with manual search. Subsequent to the review of titles and abstracts, 57 relevant articles was selected.Results: The mean and standard deviation values for interalar width, intercanine tip distance, and the width of anterior maxillary teeth were 36.38±3.81, 34.15±2.05, and 48.23±2.068 mm, respectively. There were significant relations between interalar width, intercanine tip distance and widths of the six anterior teeth.Conclusion: Tooth-supported cantilevered FPDs can be used as an alternative for distal extension RPDs, saving intact anterior abutment teeth (such as upper central incisors) and replacing multiple missing teeth with pier abutment. Three primary factors which should be considered carefully to optimize the prognosis of cantilevered FPDs are: abutment selection, control of occlusal forces and provision of connector rigidity.

Introduction: One of the main problems in esthetic dentistry is closing diastema between teeth with a direct technique without creating the black triangle (gingival embrasure lacking papilla). Black triangle will ruin the patients' smile and is not desirable. Composite resin used to close diastema should have adequate convexity from gingivo-incisal direction to avoid this problem. Various techniques have been introduced to close diastema, some of which are time-consuming or cannot provide proper contour.Case report: This article describes a case in which diastema between two teeth was closed with direct composite resin with minimum amount of time. Although closing diastema with direct composite depends on operator skill in most part, this technique is probably less dependent on operator skill compared to other techniques.Conclusion: Closing diastema between anterior teeth with composite resin with direct technique is conservative and timesaving, and the presented technique which provides adequate contour can be carried out very easily by many dental practitioners.

Introduction: Central Odontogenic Fibroma is an uncommon benign ectomesenchymal and somewhat controversial tumor of the jaw. This lesion is seen in all age groups and in both the mandible and maxilla.Case Report: In this report, a rare case of Central Odontogenic Fibroma with the simple type predominance is presented in a 57-year-old man in the right maxillary canine edentulous region.The lesion was surgically removed. After enuleation and curettage, no recurrence was recorded during the next six months.Conclusion: Microscopically, because of histopathologic variability, two common variants have been described for COdF: Simple and WHO type. However, this microscopic differentiation may be academic because it appears to have no correlation with clinical behavior of the two variants.