Vol 6, No 1 (2009)
Proceeding Abstracts
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Objective: The aim of the present study was to investigate the demographic and pathological aspects of adenoid cystic carcinomas (ACC) in an Iranian sample based on a 20-year archive review.
Materials and Methods: In this descriptive study, tumors of the head and neck registered between 1980 and 2000 were evaluated and cases of ACC were selected. Patients' medical records and pathology reports were reviewed. Variables such as age, sex, duration of disease, symptoms, site of tumor involvement and tumor diameter as well as pathologic features were recorded. Analysis was performed using chi-square and t-tests; P<0.05 was considered as the level of significance.
Results: ACC was the most common malignant tumor followed by mucoepidermoid carcinoma and adenocarcinoma NOS. A total of 120 ACCs were found, of which 50.8% occurred in females and 49.2% in males. Patients' ages ranged from 5 to 90 with a mean of 49.2 (SD=15.9) years. In 60.9% of cases, minor salivary glands were involved and the
palate was the most common site. The greatest tumor diameter was between 2-15cm with a mean of 4.6 cm (SD=2.9). The most prevalent histologic appearance was cribriform, followed by tubular pattern. No significant relation was observed between lymph node metastasis and patients' age, sex, disease duration, greatest tumor diameter and site of involvement.Conclusion: Our findings were relatively similar to other reports from different parts of the world. Further analytic and case-control studies are recommended to gain a better understanding of different aspects of ACC.
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Objective:
The use of sugar-free chewing gums has been reported to be highly effective in the prevention of dental caries. This study carried out to compare the effect of mastic gum and a xylitol chewing gum on remineralization of caries-like lesions.
Materials and Methods:
In this cross-over, single blinded, in situ study, first, artificial caries-like lesions were created in six extracted human premolars. Then axial sections were cut from each tooth to the thickness of approximately 100 microns. Fifteen adult subjects participated in the study. Lower removable appliances with rectangular boxes in the lingual surfaces were fabricated for them. One tooth section was placed in each of these boxes. The appliances were worn for two separate periods of three weeks each. The subjects chewed five sticks of gum (mastic gum and or xylitol chewing gum) per day, each for 20 minutes. In the second period, the sections were replaced with new ones and the participants were instructed to change their gums. The sections were examined by polarized light microscope and the difference between the size of demineralized areas before and after intervention were recorded. Paired t-test and LSD test served for statistical analyses.Results:
The decrease in demineralized surfaces in both groups was statistically significant (mastic gum: P=0.018, xylitol gum: P<0.001). The difference of average decrease between the two groups, however, was not statistically significant (P>0.05).Conclusion:
Chewing both mastic gum and xylitol chewing gum improved the remineralization of caries-like lesions but their effects were similar. -
Objective:
In this study, the usefulness of Panoramic Mandibular Index (PMI) on panoramic radiographs in diagnosis of osteoporosis was evaluated and its correlation with bone mineral density (BMD) of the neck of femur and spine was determined.
Materials and Methods:
In this cross-sectional study, 140 patients (all females) were categorized as either normal, osteopenic or osteoporotic according to the WHO classification in relation to their spinal and femoral BMD determined by dual energy X-ray absorptiometry. Regarding menstruation, they were also divided into menopausal, nonmenopausal, or oophorectomized groups. Panoramic radiographs were taken from all the women in the study. PMI was calculated. The data were analyzed using Kruskal-Wallis, Mann-Whitney, and Pearson tests.Results:
Specificity and sensitivity of PMI in differentiating normal and osteopenic/ osteoporotic cases were 88% and 44%, respectively. The mean PMI of nonmenopausal women was significantly different from those of menopausal and oophorectomized ones. There was a weak correlation between PMI and spinal BMD (r=0.23, P<0.05) and a moderate negative one between age and mean PMI (r=-0.45, P<0.0001).Conclusion:
Dental panoramic radiographs can be used in clinical practice to assist identifying individuals with low bone mass. -
Objective:
The aim of this study was to evaluate the effect of concepsis (a chlorhexidine gluconate based cavity disinfectant) application on composite restorations micro leakage, using two adhesive systems: Excite and Adhese.
Materials and Methods:
In this interventional experimental study, class V cavities were prepared on buccal surfaces of seventy-two extracted bovine incisors. The specimens were randomly divided into 6 groups (n=12): A1: Acid Eching (AE), Excite; A2: AE, Concepsis, blot drying, Excite; A3: AE, Concepsis, water rinsing, Excite; B1: AE (only enamel margin), Adhese; B2: AE (only enamel margin), Concepsis, blot drying, Adhese; B3: AE (only enamel margin), Concepsis, water ringsing, Adhese. Afterwards, the cavities were restored with tetric Ceram composite, thermo-cycled (5 to 50°C, dwell time: 30s, 1000 cycles,), immersed in 0.5% methylen blue for 24 hours and the dye penetration was evaluated and scored on a scale on 0 to 4 under stereomicroscope (×30). The data were analyzed using Kruskal-Wallis and Multiple Comparison tests.Results:
The only statistically significant difference was found between groups B1 and B2 at both occlusal and gingival margins. (P<0.05)Conclusion:
Rinsing off the cavity disinfectant (Concepsis) before the bonding procedure does not affect the seal at the resin-tooth interface when using either of the adhesive systems; however, the sealing ability of Adhese seems to be inhibited by the remnants of the disinfecting agent. -
Objective:
The aim of the present study was to compare microtensile bond strengths (μTBS) of glass fiber posts to different parts of intra-radicular dentin using conventional method and one-shot technique under different light intensities.
Materials and Methods:
Twenty-eight single-rooted teeth were prepared to receive fiber posts: Group 1: Conventional method at light intensity of 600 mW/cm2; Groups 2, 3 and 4: One-shot technique at light intensities of 600, 800 and 1000 mW/cm2 respectively. Dumbbell- shaped slices were obtained from the samples and submitted to micro-tensile testing. The data were analyzed using two-way ANOVA and paired-samples t-test.Results:
There were no significant differences in μTBS values of the cervical and middle thirds between the groups (P>0.05). μTBS values in the cervical thirds in groups 2 and 3 were significantly higher than those in the middle thirds (P>0.05). However, there were no such differences in groups 1 and 4 (P>0.05).
Conclusion:
It is proper to simultaneously cure the resin cement and the adhesive agent (one-shot technique); however, in that case, high light intensities (1000 mW/cm2) are recommended to achieve identical bond strength values in the cervical and middle thirds. -
Objective:
Several studies have compared ferric sulfate and formocresol pulpotomy in primary molars. The results of these studies, however, could not be compared due to differences in evaluated outcomes (clinical, radiographic, or histologic) and follow up duration. The aim of the present study was a systematic review of similar studies and a metaanalysis of their results to provide the latest evidence on the issue.
Materials and Methods:
Web-based search was done in EMBASE, Cochrane, Pubmed, Google Scholar, IranMedex, Scientific Citation Index (SCI), and Scopus index databases. A hand search also was conducted in scientific and research dental journals approved by the Ministry of Health and Medical Education of Iran. Eight randomized clinical trial articles were selected. Clinical success, clinical and radiographic success (total success) rate were assessed as outcome variables. Peto test served for data analysis.Results:
The clinical success of formocresol pulpotomy was comparable to that of ferric sulfate (P=0.574). In addition, the difference between total success rate of the two methods in different studies was insignificant (P=0.42).Conclusion:
No significant difference existed between the total success rate of formocresol and ferric sulfate pulpotomy, and ferric sulfate can be an appropriate alternative for formocresol. -
The aim of this study is to review the existing literature about temporomandibular disorders (TMD) and parafunctional habits (bruxism) and their relationship in children and adolescents, which is still controversial. TMD is a collective term used to identify a group of musculoskeletal conditions of the temporomandibular region. Bruxism defined as the habitual nonfunctional forceful contact between occlusal tooth surfaces. Some studies have linked oral parafunctional habits to TMD, whereas others did not observe this relationship. The role of bruxism -as is currently described- can be considered a controversial and unresolved issue. Taking all evidence together,the authors suggest that there is not any clear relationship between bruxism and TMD.
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A 7.5 year-old girl was seeking orthodontic treatment because of severe ectopic eruption of maxillary first permanent molars. It was a rare case that represented approximately horizontal view in panoramic radiograph. The severity of problem was high, but since the patient had maxillary deficiency, it was important to perform the treatment without extraction. Treatment began with extraction of upper deciduous second molars and continued with a modified Nance appliance. The period of treatment was 16 months and the result was excellent. This satisfactory outcome of treatment justifies clinicians to evaluate and diagnose this group
