JOURNAL OF ISLAMIC DENTAL ASSOCIATION OF IRAN (MAJALLAH-I-DANDANPIZISHKI)
Year:2005 | Volume:17 | Issue:2 (54)|Papers Count:15

Background and Aim: Debonding of bracket is one of the common problem in orthodontics. The goal of this study was to evaluate and compare shear band strength of a new cyanaacrylate, a kind of moisture palymerized adhesive, with a conventional composite resin far orthodontic bandings.Materials and Methods: In this experimental study, based on observational technique, a total number of 74 caries free extracted premalar teeth of (12-16) - year - old patients, were collected, water - rinsed and polished with pumice. Samples were randomly assigned in two groups. In group I, the teeth were etched with 37% phosphoric acid, the primer was applied and the brackets were banded with Unite No - mix campsite. In group 11, the teeth were etched with 35% phaspharic acid and the brackets were banded with Smart band. The specimens were mounted and subjected to a crosshead speed of 0.5 mm/min of Instron machine. Shear band strength (SBS) differences between two groups were evaluated statistically using Kalmagrov - Smirnov test and t - test.Results: The results of this study indicated that no significant difference, in shear band strength, existed between cyanoacrylate and No- mix composite groups (P=0.468). Moreover, a comparative study on shear bond strength of a new cyanoacrylate and a conventional composite resin for orthodontic bandings there was no. statistically significant difference, in debonding area, between two. Groups (P<0.001) so as demanding occurred mostly inside adhesive among cyanoacrylate group indicating a kind of cohesive failure. Conclusion: Cyanoacrylate has the potentiality to be used as a banding agent far orthodontic brackets.

Background and Aim: Proper sealing capability of a restorative material plays an important role in its long - term durability. The goal of this study was to investigate the effects of eugenol containing temporary restorations on the microleakage of composite restorations.Materials and Methods: Class V cavities were prepared on the buccal surface of 60 newly extracted, non - carious human premolars. The teeth were randomly divided into two groups of 20 each. Specimens in group I were covered with coltosol cement (eugenol free) and in group 2 with IRM containing eugenol. The temporary restorations were removed mechanically with an ultrasonic scalar after one week storage in distilled water at 37 degrees. The cavities were thoroughly washed and restored with Z100 composite according to the manufacturers instructions. After thermocycling and dye penetration testing, microleakage of samples were measured and data were analyzed using t - test.Results: The mean rnicroleakage, at occlusal and gingival margins, in coltosol group were 0.025 and 0.28, respectively and in zonalin group were 0.84 and 1.01, respectively. There were statistically significant differences, in the microleakage of both enamel and dentin margins, between two groups (P<0.05). Gingival margins showed significantly greater rnicroleakage than occlusal margins (P<0.05). Conclusions: It seems that eugenol containing temporary filling materials significantly increase microleakage in composite restorations so the clinical application of these materials as temporary filling is not recommended.

Background and Aim: Success of failure with complete dentures can not be exclusively predicted based on residual ridge morphology because psychologic factors play on important role in patient's attitude and satisfaction with the prosthesis as well. The goal of this study was to investigate the effects of patient's attitude and expectation toward the complete denture as well as the clinician on the rate of his satisfaction with treatment.Materials and Methods: This analytic-descriptive study was conducted on 90 patients referred to Prosthodontics departments of Isfahan and Azad Khorasgan dental faculties. Patients were interviewed at two stages using standardized questionnaires. At the fist stage, during the final visit prior to the prosthesis delivery, patients were asked about their attitudes and expectations of the fabricated prosthesis and the clinician. At the second stage, three months following delivery, patient's opinion on the success rate of the treatment was investigated and recorded.Data were subjected to Pearson's correlation coefficient and t - test.Results: The studied patients consisted of 90 patients, 53 females and 37 males with the mean age of 57.2 years. The mean score of positive attitude toward complete denture was 22.67±2.44, out of 30. The mean score of positive expectations toward treatment was 11.63±1.47, out of 15. Patients' attitudes mean score toward the clinician was 14.52±0.34, out of 15. There was no significant relationship between the investigated variables and sex, expect for patient's attitude toward the clinician (P=0.02). In addition, no significant relationship was found between all the investigated psychologic factors and patients' satisfaction. Conclusion: The prediction of patient's satisfaction toward complete denture, based on psychologic factors, is not an easy procedure so more studies are recommended in this field.

Background and Aim: The most desirable characteristic for an ideal elastomeric chain is the possession of a light and permanent force which unfortunately is not observed with commercially available chains. The purpose of this study was to evaluate force decay in 4 commercially available orthodontic elastometic chains (Dentaurum, American memory, G&H and orthotechnology) and the effects of different elongation ranges on force decay pattern, and also force decay difference in pre-elongated and non pre - elongated chains.Materials and Methods: Sixty samples of each product were obtained and divided into three groups. The first groups were extended 3 millimeters, second groups were extended 6 millimeters and third groups were firstly stretched by 100% of their initial length and relaxed and then extended 6 millimeters. The samples were stored in artificial saliva for 3 weeks and thermocyded daily. The force amounts were measured at 7 times (0, 2, 4, 24 hours and 1, 2 and 3 weeks) by DARTEC machine. ANOVA and DUNCAN tests were used to determine statistically significant differences among groups.Result: Force decay patterns in these 12 groups were evaluated and compared. Force decay patterns in 3 groups of each product were significantly different (P.V = 0.000). The differences in force decay between 4 products were statistically significant (P.V = 0.000). G & Hand orthotechnology chains were not significantly different in the third week (P.V = 0.26).Conclusion: The higher initial force cannot increase force decay. Both the force amount and force decay, in the third group, were lower. The highest force decay was observed in orthotechnology chain and the lowest in American memory chain. Pre – elongation and extension by 40% of the initial length would provide the most satisfactory orthodontic force.

Background and Aim: Numerous studies have shown the role played by sugar- free chewing gums in the reduction of dental caries. The goal of this study was to compare the effects of three commercial sugar free chewing gums and one containing sucrose on streptococcus mutans and pH of saliva.Materials and Methods: This randomized clinical trial research was conducted on 120 female students of a day - night high school for seven weeks. The subjects were randomly divided into four groups. One group used a commercial sucrose- containing gum named Aidin (group A) and three groups used sugar - free gums named Relax (group B), Dirol (group C) and Happy dent (group D). The subjects used three gum sticks daily after main meals for about five minutes. Saliva sampling was performed unstimulated at three times: at baseline, at the third and seventh weeks, after sleep and before tooth brushing. Samples were immediately transferred to microbiology department of medicine faculty, Isfahan University. Data were subjected to repeated measure, Hottelling's trace and t – paired tests and compared by Variance (ANOVA) and DUNCAN analyses.Results: During the first three weeks, all groups even the sucrose - containing gum group showed a significant decrease in the salivary streptococcus motans: A (P=0.038), B (P<0.001), C (P=0.035) and D (P=0.033), but between the third and seventh weeks, the decreases were only significant in groups C and D (P=0.024) and (P=0.001). However, intergroups comparison showed that, in spite of the third week, the decrease of salivary streptococcus motans, in the seventh week was statistically significant in groups B, C and D, as compared with group A, (P<0.05). Salivary PH, in group A, despite other groups, showed a significant decrease in the seventh week of sampling (P=0.005) and the observed difference between groups A and D was statistically significant (P<0.05). One of the other interesting findings was the significant increase of the salivary bacterial colonies, other than streptococcus mutans, in group B during the seven weeks of study (P<0.001).Conclusion: Three - week chewing of any type of gum after main meals could decrease the level of salivary streptococcus mutans, however; during a seven - week period, the decreasing effects of sugar - free gums were significantly higher.

Background and Aim: Considering the potential role of dentists as both carriers and hosts of various infections, the goal of this study was to assess infection control compliance and particularly vaccination against hepatitis B among dentists.Materials and Methods: This pilot study was conducted in the annual congress of Iranian dentists in 2004 using an anonymous self - administered questionnaire. Response rate among congress participants was 31.75% (334 dentists). All participants were asked to answer voluntarily. Data were analyzed using SPSS 11.5 software, Fisher exact and Mann – Whitney U tests.Results: Mean age (±SE) and duration of practice in dental profession were 35.9±0.57 years and 106.9±6.4 months, respectively and 54.5% were males. Rate of routine use of gloves, facemasks and protective eye glasses were 93.1%, 87.1% and 63.8%, respectively. Female dentists showed higher protective behaviors as compared with males (P<0.05). Vaccination against HBV was reported in 94.9% of the studied subjects where as 1.5% of them had acquired immunity, however; complete vaccination was done in 74.8% of dentist and only 47.9% of them were reported to be checked for HBs antibody after vaccination. There was a straight relation between vaccination against HBV and using protective methods (P<0.05). The Most common reason for non- vaccination was lack of access to vaccine ( 58.1%). Conclusion: The rate of dentists' vaccination against HBV was at the range of other countries and almost all authors agree to encourage dentists to care more about cross - infection control.

Background and Aim: Geographic tongue appears as an atrophic area with a keratotic border often seen on the dorsal surface and lateral borders of the tongue. The goal of this study was to assess the level of serum zinc in patients with geographic tongue.Materials and Methods: In this analytical cross - sectional study, 80 patients, 29 cases and 51 controls, with the age ranges of 15 - 58 years among test group and 16 - 59 years among control group, were participated.In order to determine the level of serum zinc, 5cc venal blood was taken from each patient.Serum was detected from blood samples using santryfusion. The level of serum zinc was measured by spectrophotometry and Randox kit. The data were analyzed using SPSS software and two Samples t - test.Results: The findings of this study showed that the level of serum zinc was lower in patients with geographic tongue as compared to the controls (P<0.05). Out of 29 patients in test group, 6 patients showed serum zinc level lower than normal where as out of 51 controls, 4 of them had lower than normal serum zinc level.Conclusion: Zinc deficiency can probably be an effective factor in filliform papillae atrophy and zinc is likely related to the development of filliform papillae.

Background and Aim: Squamous cell carcinoma (SCC) is the most prevalent neoplasm in oral cavity and due to the numerous complications arising from lesions or treatment and its high mortality rate has been paid too much attention. The goal of the present study was to evaluate clinical and histological parameters in patients with SCC referred to Pathology department, Dentistry Faculty, Tehran University of Medical Sciences.Materials and Methods: In this case series study, clinical and histological information of 271 patients affected with SCC were collected through the evaluation of all documents in pathology department from 1966 to 2002. All surgical documents and histological slides were studied and analyzed using SPSS version 11.0 X2 test and t test.Results: Malignancy score was higher in males than females. The maximum, minimum and average age of patients was 85, 19 and 56.73 years, respectively. The majority of lesions were observed during the sixth decade of life and the ratio of males to females was 5:4. Malignancy score, in young patients, was higher than old ones. The most common site for lesions was mandibular ridge and the least common was the upper lip. Lesions of maxillary sinus and soft palate had the highest and lesions of the upper lip had the lowest malignancy score. 74% of the patients were smokers. Most of the lesions showed high keratinization, slight inflammation and polymorphism and were of grade I.Conclusion: SCC incidence is more common among males compared to females. Patients older than 50 years are considered as the high risk group for this neoplasm. Mandibular ridge is the most common site. Majority of the lesions are well differentiated in oral cavity.Malignancy score is higher in males and young patients than females and old patients.

Background and Aim: The goal of this study was to evaluate the effects of 37% phosphoric acid and self- etching primer on the bond strength of composite resin to enamel.Materials and Methods: Twenty bovine mandibular incisors were mounted in self – curing acrylic resin, and facial enamel surfaces were ground wet on 600 - grit disc paper. Then specimens were divided into three groups of ten. Different enamel surface treatments were applied as follows: Group A: Etching with 37% phosphoric acid and enamel bonding agent (Colten). Group B: Self-etching bonding agent (Prompt - LP). Group C: Etching with 37% phosphoric acid and self - etching bonding agent (Prompt - LP). After adhesive curing, a column of composite of 2 mm diameter was cured on the surface. After one - week storage and thermocycling, specimens were debonded at a cross – head speed of 1mm/min using an Instron machine. The teeth were examined stereomicroscopically to assess the site of debonding. The data were subjected to one - way ANOVA and LSD test at 0.05 level of significance.Results: The mean shear bond strength values were 15.4±6.5, 24.8±9.7 and 25.4±11 MPa for groups A, Band C, respectively. The enamel- resin interface was the most common site for bond failure in group A. Cohesive failure, in composite or enamel was more common in C d groups Band C, respectively. The differences between groups B and C with A was significant Operative but no statistically significant difference was found between groups Band C. Conclusion: Self - etching agents can be used as alternatives for conventional phosphoric acid enamel treatment.

Background and Aim: Denture adhesives are one of the productions which are used to increase retention and stability in complete dentures and are found in three forms of powders, paste and sheet. These products are used clinically in different stages such as stabilizing temporary bases in jaw relation record stage. In addition, for patients suffering from xrostomia due to medication side effects, history of head and neck radiation, systemic or salivary gland diseases and also for those with major problems in wearing dentures because of insufficient retention, are applicable.The goal of this study was to determine the rate of knowledge and use of Tehran's dentists of these products in order to improve their knowledge in this field, if necessary.Materials and Methods: In this descriptive study, 250 dentists of Tehran were participated.Data were collected through questionnaires. The questions were mostly arranged on the knowledge and use of denture adhesives among dentists. In the evaluation of knowledge, dentists were classified in groups of good, moderate, weak and lack of knowledge. In the evaluation of use, dentists were classified in good, moderate and weak practice groups. Results: Dentists' knowledge toward denture adhesive was good, moderate, weak in 14%, 32% and 37.6% of cases, respectively. 16.4% of dentists had no knowledge. 10.4% of dentists had good practice, 69.2% had moderate and 20.4% had weak practices toward denture adhesives. Additionally, 15.2% of dentists used these products where as 84.8% did not use at all. Conclusion: Dentists' knowledge on denture adhesives was not sufficient and more training seemed necessary.

Background and Aim: Evaluation based on satisfaction is one of the evaluative indices, paid attention recently in hospitals and treatment organizations. The goal of this study was to evaluate the satisfaction rate of patients referred to Dentistry Faculty of Tehran University of Medical Sciences.Materials and Methods: This analytical- descriptive study was conducted cross – sectionaly on 550 patients who referred to different departments of dentistry faculty, Tehran University of Medical Sciences in 2003. Data were collected using a questionnaire consisted of two parts.The first part was related to personal and demographic characteristics of patients and the second part was related to research goals consisted of 18 questions included in 7 sections on subjects such as: satisfaction rate of admission procedure, the type of secretary behavior toward patients, hygiene and infection control. Students' behavior, professors supervision, treatment expenses and general satisfaction of all procedures.Data were subjected to SPSS software and chi2 test for statistical analysis.Results: Totally 57.8% of the patient referred to the Dental Faculty, Tehran University of Medical Sciences was fully satisfied with the delivered services, 25.8% were relatively satisfied, however; 16.4% were dissatisfied. A significant relationship was found between the rate of patients' satisfaction with insurance (P=0.011), admission procedures (P=0.019), student behavior (P=0.0001), professors supervision (P=0.0001), and treatments cost (P=0.0001). Conclusion: According to the findings of this study, it is indicated that the satisfaction rate of patients referred to Tehran Faculty of Dentistry, despite all weaknesses and shortages in the delivery of services, is estimated at an approximately desirable level.

Background and Aim: The patients with cancer are predispose local and general infection including oral infection. The goal of this six-month study was to evaluate the etiology and clinical characteristics of oral lesions in cancerous patients, admitted at the Hematology - Oncology ward of Mashhad Imman Reza Hospital.Materials and Methods: This descriptive cross-sectional study was conducted for six months on 14 cancerous patients who underwent chemotherapy for the first time. In order to diagnose the etiologic factor, in addition to clinical features, cytological examinations and microbial culture were also used. Statistical evaluations were conducted using SPSS software and Chi2 test.Results: Oral lesions were found in a total number of 14 patients, 9 were candidial and 6 were herpetic (one of the patients was affected with both lesions). Bacterial lesions were not observed among all cases. This study showed that candidia was the causative agent of 64.2% of oral infections among patients under chemotherapy and statistically significant relationship was found between bacterial infection with fever, leucopenia and broad spectrum of antibiotic therapy, (P<0.05). Moreover, 42.9% of the lesions were caused by H.S.V with a significant relationship between this infection and fever.Conclusion: According to the results of this study, conidial and herpectic infections are major causative agents of oral lesions among patients under chemotherapy. Clinical views of candidallesions were in the form of a white and diffuse plaque and that of herpetic lesions was as localized and unilateral large ulcer with raised white border. The absence of bacterial infections can be attributed to broad spectrum of antibiotic therapy Faculty of Dentistry or possibly laboratory errors.

Background and Aim: Exact and reliable diagnosis is the result of positive correlation and concordance between clinical and pathological diagnosis. The aim of the present study was to investigate the existing concordance between clinical and pathological diagnosis.Materials and Methods: In this cross- sectional study, oral lesions files, from archive of Razi pathological laboratory in Rasht during 2000 - 2002 were reviewed and necessary information including age, sex, location of lesion, clinical and histopathological diagnosis, and surgeons specialties were recorded. Concordance between clinical and histopathological diagnoses was calculated using kappa test.Results: The total number of 466 oral lesions were recorded out of them 81 cases (17.38%) did not have any clinical diagnosis. Sensitivity range was between 40% to 79%. No concordance was found between lesion location and surgeon specialty. Reactive lesions of soft tissue were the most common ones (22.1%). The most concordance was found in mucocutaneous lesions diagnosis (k=0.77) and then in retentional salivary lesions (k=0.72). However, cystic lesions (k=0.52), reactive lesions of soft tissue (k=0.52) and infectious lesions (k=0.29) showed less agreement.Conclusion: Considering the lack of clinical diagnosis in too many cases and low level of sensitivity in this study, further evaluation for the removal of the mentioned complications is necessary. Moreover, careful review of clinical symptoms in cystic, reactive and infectious lesions is recommended.

Background and Aim: Posterior crossbite is a common phenomenon in primary dentition which is classified in three general types of skeletal, dental and functional which are not mostly self - corrected, however; a suitable and on - time treatment may prevent it to change into a skeletal disorder. The goal of this study was to determine the prevalence of posterior crossbite among 3-5 year-old nursery school's children in Zahedan.Materials and Methods: In this cross - sectional descriptive study, data were gathered through clinical examination and questionnaire in 870 children, 500 boys and 370 girls. The unilateral crossbite was characterized by cusp - to - cusp position of molars in central occlusion and the mandible, to find a stable occlusion, had to slide to one side. If there was no midline deviation it was classified as bilateral cross-bite. The data were analyzed using descriptive statistical methods and X2 test.Results: The prevalence of posterior crossbite in the studied group was 3.2%. The posterior cross-bite was more in girls (4.3%) than boys (2.4%). Unilateral posterior crossbite was observed in 92.8% of cases and bilateral posterior crossbite was seen in 7.2%. Conclusion: The prevalence of posterior crossbite was 3.2% in (3-5) year - old children in Zahedan nursery schools.

Background and Aim: An acceptable readiness to confront dental and medical emergencies requires scientific background and adequate equipment than result in self - confidence in dentist or clinician. The goal of this study was to evaluate emergency equipment and drugs in Karaj urban dentistry clinics as well as the ability of dentists to use them in 2003-2004. Materials and Methods: This cross - sectional descriptive study was conducted using a questionnaire. After reviewing an overall list, the urban dentists of Karaj were identified to complete the questionnaire. The data were collected and analyzed by descriptive statistics and Pearson correlation test.Results: 99% of dentists believed in the occurrence of emergency cases in dental clinic and 61.9% of them faced with such cases. Approximately 40% of the studied dentists had 1- 4 entities of emergency equipment and drugs in their kits. The ability to use emergency kits in males was higher than females. Almost one - fifth of dentists confronted with CPR cases where as 73% of them managed to perform it successfully. University courses were identified as the first training source for medical emergencies. Along with an increase in work period, emergency kit and drugs existing in the clinics became more acceptable showing the significant relationship between these two variables.Conclusion: In our country, the same as other countries, emergency cases are likely to happen in dental clinics whereas emergency facilities are involved with a lot of shortages indicating an urgent need for higher instructions and modem equipment in the clinics.