Journal of Isfahan Dental School
Year:2010 | Volume:6 | Issue:3|Papers Count:12

Introduction: A large number of materials have so far been applied to restore tooth perforations.Gray MTA is now the material of choice for such purpose. However Portland cement with a lower price and high structural similarity to MTA can be a suitable substituent. The aim of this study was to compare the success of mechanical perforation restorations with Portland cement and MTA.Materials and Methods: in this comparative clinical trial, 30 perforations in the teeth of 30 patients were treated at Mashhad Dental School Clinic using either MTA or Portland cement type IV which was opaqued using 20% Bismuth Oxide. The patients were invited for clinical and radiological follow-up 3 and 6 months later. Two endodontists separately evaluated the success of restorations on the basis of X-ray and clinical examination. Chi square test was used for statistical analysis of the collected data.Results: In 3 and 6 month interval follow up just one case of failure was recorded in both MTA and Portland cement groups. No significant difference was found between the two study groups (p value=1).Conclusion: Portland cement type IV can replace gray MTA in restoration of dental perforations where aesthetic aspects are not of much concern.

Introduction: Successful radiography requires a true imagination of central ray. Some technical errors however happen as a result of maladjustment of central ray. Many dental students who begin to learn radiography do not have a comprehensive imagination of the central ray. Using a laser guided indicator for central ray in such cases may serve as a useful training means for better adjustment of central ray.Materials and Methods: This in vitro study was carried out at the Department of Radiology, Dental School of Isfahan University of Medical Sciences. A total of eighteen students were divided into two groups of nine. In the first group the periapical technique was taught without laser guided indicator while in the second group laser guided indicator was applied in training the students. All students took X-rays from the phantom. Laser guided indicator is made of two low power red laser diodes and is capable of making two perpendicular rays forming a cross (+) in the center of tube which indicates central ray. Totally 216 X-rays were taken and technical errors and the quality of X-rays were evaluated. The results were analyzed statistically via Mann-Whitney and chi Square tests (a=0.05).Results: The X-rays taken by students showed significant differences in Cone Cutting (p value=0.014), Overlapping (p value=0.018) and Elongation (p value<0.001) between the two study groups. In the subjective review of X-ray quality, the difference was also significant (p value<0.001).Conclusion: The use of laser guided indicator as a training aid seems to be practical for easier learning of central ray adjustment and reduction of technical errors in taking X-rays by dental students.

Introduction: Oral Lichen Palnus (OLP) is a well clinically and histologically described chronic mucocutaneous disease with unknown etiology. A large number of both systemic and local predisposing factors have been implicated in the pathogenesis of OLP. Saliva and its constituents are considered to play an important role in the homeostasis of the oral cavity and therefore any alterations in their quantity or quality may give rise to various oral diseases. The aim of this study was to evaluate the salivary peroxidase levels in patients with oral ulcerative lichen planus.Materials and Methods: in this case-control study, a total of twenty patients with OLP (mean age 35.4 years) were included in the case group. The same number of normal healthy individuals (mean age 39.3 years) were put into the control group. Subjects collected their saliva between 8-10 am using the simple method of unstimulated spitting. Saliva samples were collected into calibrated tubes (0.1 ml) during a five minute period. Salivary peroxidase level was checked based on Putter and Becker method. The data were analyzed in SPSS using t-student test (a=0.05).Results: The mean±SD salivary peroxidase levels were 3.59±0.71 and 3.69±0.74 in the case and control groups, respectively. The difference between the two groups was not statistically significant (p value=0.669).Conclusion: Within limitation of the present study, salivary peroxidase level does not seem to have a role in the pathogenesis of OLP.

Introduction: It is not only hormonal changes but also natural phenomena such as puberty, pregnancy and menopause that predispose women to many disease conditions. The aim of this study was to compare the prevalence of oral symptoms between premenopausal and post menopausal females.Materials and Methods: This was a cross sectional, descriptive-analytic study. A total of 205 women aging from 44 to 55 years who referred to the School of Dentistry Clinic at Kerman University of Medical Sciences for oral examination in the year 2007 were included.The case group consisted of 72 (35.1%) postmenopausal women. The control group included 133 (64.9%) premenopausal women. The oral manifestations considered in this study were xerostomia, taste distribution, gingival bleeding and burning mouth. The collected data were finally analyzed with t-test and chi-square using SPSS 15.Results: According to the results of this study, the most prevalent symptom in postmenopausal subjects was xerostomia (40.5%). Other oral manifestations were taste distribution (14.6%), gingival bleeding (14.6%) and burning mouth (6.3%). It was shown that taste distribution, xerostomia, and burning mouth in postmenopausal women were 3.5, 1.8, and 4.1 times more common than in premenopausal women, respectively. Moreover, it was found that premenopausal women complained of gingival bleeding more than postmenopausal women. Also the prevalence of xerostomia regardless of age was found to be significantly greater in postmenopausal women than in premenopausal women.Conclusion: It seems that oral symptoms are common problems in postmenopausal women.Therefore, dentists need to refer postmenopausal women with oral symptoms to a gynecologist for more careful examinations and medical interventions if necessary.

Introduction: Bond Strengths among denture base resins and various types of reline materials are not always satisfactorily high. Therefore efforts have been made to use materials similar to resin base dentures and bonding agents to increase infirmity. This study compares bond strength and deflection of a hard chair side reline material with two denture base resins.Materials and Methods: In this experimental study, 54 resin specimens with the size of 65×10×2.5 mm were prepared. These specimens included intact heat cure (M), cold cure (F), acrylic resin specimens bonded with the same resins (M-M, F-F) and specimens bonded to a hard chair side reline material (M-G, F-G). All specimens were stored in sodium hypochlorite 8 hours a day for 3 months and were then thermocycled (2000 cycles, 5 to 55oC). The transverse bond strengths (FMax) and deflections (DFMax) were evaluated with three point loading test. The results were analyzed with twoway ANOVA followed by Games Howell & Gabriel’s and Kolmogrov-smirnor test (a=0.05).Results: F Max for different types of resins and reline materials showed significant differences (p value<0.05). Although DFMax differences between reline materials and their interactions with different types of resins were significantly different (p value<0.05), no significant difference among the types of resins could be found (p value=0.263). Comparing the reline materials with denture base resins, cold cure resin was shown to have statistically different FMax and DFMax (p value<0.05).Heat cure resins showed statistical differences on FMax between intact resins when relined with the same resins and relined with hard reline (p value<0.05).Conclusion: Bond strength of the cold cure denture base resin group (F) to the same resin was higher than hard reline, but bond strength of hard reline material with heat cure denture base was similar to the bond strength of the same reline, and in this group, maximum deflection in bonded resin with the same resins were showed.

Introduction: Bacterial plaque is the most common etiology of oral conditions such as dental caries, gingivitis and periodontal disease. One of the most common periodontal diseases is gingivitis. Elimination of bacterial plaque is the main goal in treatment of this destructive inflammatory disease. The purpose of this study was to investigate the prevalence of Streptococcus mitis in bacterial plaque and its sensitivity to b-lactam antibiotics.Materials and Methods: In this cross sectional study, we evaluated the effectiveness of 10 b-lactam antibiotics for the treatment of gingivitis via determining the antimicrobial susceptibility of the major pathogens. This study included 100 patients referring to Oral Disease Department at the School of Densitry, Isfahan University of Medical Sciences, from 2003 to 2004. Sampling of plaques on the cervical region of anterior teeth was performed with periodontal probes. Samples were then cultured into chocolate and blood agar media. In this study a total of 361 types of bacteria were isolated. Isolated strains were identified through biochemical tests. The antimicrobial susceptibility of Streptococcus mitis to 10 b-lactam antibiotics was assessed by Disk plate and Kerby-Bauer. The collected data were analyzed via t-test on a computer using SPSS (a=0.05).Results: The results showed that there were 204 Streptococcus strains (55.9%). Streptococcus mitis formed 12.93%. The sensitivity of Streptococcus mitis to b-lactam antibiotics was more than 80% except for penicillin and ampicillin. As much as 2% of strains were sensitive to clindamycin.Conclusion: Streptococcus mitis in the dental plaques seem to be sensitive to b-lactam antibiotics.Therefore such antibiotics might be considered for the treatment of gingivitis.

Introduction: There are different ways such as anthropometric measurement to estimate the size of complete denture teeth. The purpose of this study was to evaluate the relationship between interalar width, intercanine tip distance and anterior maxillary teeth width in a group of Iranian adults.Materials and Methods: This was an observational cross sectional study. The study included 120 dental students (60 males and 60 females) at School of Dentistry of Isfahan University of Medical Sciences. First, interalar width was measured with a caliper on every subject. Then the length of the imaginary line connecting the 2 canine cusp tips (intercanine tip distance) was registered on a wax index.The collective width of the six anterior teeth was recorded using a brass wire on the prepared casts.Descriptive statistical, independent t-test, Pearson correlation coefficient and linear regression were applied for statistical analysis (a=0.05).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: The dimensions seem to be greater in males. It seems use of interalar width can provide a more reliable predictive equation for teeth size.

Introduction: Dental erosion is chemical loss of tooth structure without the involvement of bacteria that is steadily spreading. At an advanced stage, the teeth become hypersensitive or the esthetics is affected. The aim of this review article is to introduce dental erosion, and giving information about its diagnosis, prevention and therapy.Review report: This review carried out by use of searching in various databases including Pubmed and ISI Web of Science from 1980 to 2010 on combination of the terms ‘dental erosion, treatment and prevention.Results: The interplay of chemical, biological and behavior factors is crucial and helps to explain why some individuals exhibit more erosion than others. The erosive potential of erosive agents, including acidic drink or foodstuffs, depends on chemical factors. Instructions related to prevention involve use of chewing gum or rinsing with sodium bicarbonate, dental adhesive or fluoride containing materials.Discussion: As a result of the improvements in composite restorative materials and in adhesive techniques, it has become possible to rehabilitate eroded dentitions in a less invasive manner.Taking into account several investigations ceramic and composite materials show good durability under acidic conditions.

Introduction: Primary extracranial and extraspinal meningioma is a rare tumor which is usually limited to head, neck or paravertebral soft tissues.Case report: This is the report of a 47-year-old man with a swelling on the right side of his face over the mandibular area. On examination a mass with firm consistency and an approximate diameter of 4 cm was found. Panoramic X-ray showed a unilacular well-defined radiolucency with a cortical border at mandibular ramus area. The lesion was then surgically excised Conclusion: Histologically, proliferation of uniform spindle cells in the whorled and fascicular pattern was seen. Immunohistochemicall study revealed tumor cells positive for Epithelial Membrane Antigen and Vimentin, but showing no reaction for cytokeratin, S-100 and ki-67. A diagnosis of ectopic meningioma with transitional pattern predominance was established according to histopathological and immnuohistochemical features of the mass.