Journal of Dentistry
Year:2011 | Volume:11 | Issue:SUPPLEMENT|Papers Count:9

Statement of Problem: Traumatic occlusion can have an adverse effect on the temporomandibular joint tissue.Purpose: This study aims to determine the histological alteration in dogs’ temporomandibular joints due to production of artificial traumatic occlusion.Materials and Methods: Twenty dogs were divided into a control group of four and two equal experimental groups. Unilateral occlusal interferences were created on the mandibular right first molars in the experimental groups.We established two experimental periods: one week and 45 days.After vital perfusion, the TMJs were separated for preparation, pigmentation, and examination by a pathologist. Descriptive statistics, Chisquare and Fisher's exact test were used to analyze the data. P.value less than 0.05 was considered as significant.Results: The findings showed no inflammatory changes in the TMJ.Increased fibrosis was found in 56.30% and vascularization in 28.12% of the disks. Fibrotic changes were detected in 46.87% and vascularization in 28.12% of the condyles. The glenoid fossas suffered from fibrosis in 15.62% of the cases.Conclusion: Traumatic occlusion leads to histopathological alterations including an increase in the fibrosis tissue and vascularization in the condyle and disk.

Statement of Problem: Bruxism is an oral habit consisting of involuntary rhythmic or spasmodic nonfunctional gnashing, grinding, or clenching of teeth, in other than chewing movements of the mandible, which may lead to occlusal trauma, tooth wear and fracture of the teeth. It would be useful to determine the relationship between occlusal interferences and bruxism in order to prevent its development by occlusal interference adjustment.Purpose: This study evaluates the relationship between occlusal interferences and bruxism.Materials and Methods: For this study, 59 subjects (22 males and 37 females) including 28 bruxers and 31 nonbruxers were selected after filling a questionnaire based on the exclusion criteria. Occlusal interferences in the centric relation and eccentric movements in the two groups were evaluated and recorded. Data were analyzed by SPSS software (Version 16) using Chi-square test.Results: The results showed that there was a statistically significant relationship between bruxism and protrusive interferences (p<0.05) while there was no statistically significant relationship in the centric relation and other eccentric movements (p>0.05).Conclusion: According to the results of this study, due to the relationship between some types of occlusal interferences (protrusive interferences) and bruxism, it would be useful to examine occlusal contacts in bruxing patients to eliminate probable causative or contributing occlusal factors.

Statement of Problem: The Strep. mutans, Staph. aureus, Cand.albicans, and Cand. Glabrata are the most common cuases of oral infections and the use of chemical drugs usually leads to drug resistant microorganisms.Purpose: The aim of this study was to investigate the antimicrobial activity of Cinnamon and Eucalyptus oils against this oral microorganism.Materials and Methods: The oils were prepared by steam distillation and their inhibitory activity at different concentrations and the minimum inhibit-ory concentrations (MIC) were determined. Strep. mutans, multi drug resistant (MDR) Strep. mutans, Staph. aureus, methicilin resistant staph. areus, Candida. albicans, C.glabrata were used in this study. The data were analyzed using Chi square and Fisher statistical test.Results: All of the bacterial and fungal isolates were sensitive to Cinnamon and Eucalyptus. Cinnamon oil showed strong promising inhibitory activity on all the S.mutans isolates at a concentration as low as 3.12%. Eucalyptus oil showed less inhibitory activity, as the least effective concentration of this oil was 25%. The MIC of Cinnamon and Eucalyptus oil ranged 12.8-51.2 and 64-256mg/ml, respectively.Conclusion: Both Cinnamon and Eucalyptus oils exhibited antimicrobial activity but their effectiveness varied. Cinnamon oil showed stronger inhibitory activity as measured by MIC determination. S.mutans, the etiological agents of dental caries, were highly sensitive to Cinnamon oil and hence it may be used as an antiseptic in toothpaste, mouthwash or chewing gum for prevention of dental caries and other oral infections.

Statement of Problem: About one out of every four individuals under the age of 18 will sustain a traumatic dental injury in the form of anterior incisal fracture. Development of fiber reinforced composite has provided new perspectives in the treatment of anterior fractured teeth.Purpose: The aim of this in vitro study was to investigate the effect and position of the fiber on the load bearing capacity of composite restorations on fragmented incisal edge of the upper central incisors.Materials and Methods: Eleven extracted maxillary incisors per group were prepared by cutting 3mm of the incisal edges horizontally. Group 1 was restored with particulate filler composite (PFC), group 2 with PFC and fiber in the mid-palatal surface, and group 3 was restored with PFC and fibers in the two sides of the palatal surface with the distance of 0.5-1mm. All the restored teeth were stored in distilled water for 7 days before they were statically loaded until they fractured in a universal testing machine. The data were analyzed using one way ANOVA and Tukey statistics.p£0.05 was considered as significant. Failure mode was visually examined.Results: The statistical analysis showed a significant decrease of fracture load from group 2 to the other two groups (p=0.05). There was statistically significant differences between groups 1 and 2 (p=0.019) and 2 and 3 (p=0.036). No significant differences were founded between groups 1 and 3.The failure mode in group 1 was debonding of the restoration from the adhesive interface, while in group 2, more than 75% of the teeth fractured below the cementoenamel junction (CEJ) or other parts of teeth. In group 3, the fractures occurred in restoration.Conclusion: These results suggest that the incisally fractured tooth restored with fiber in the mid-palatal surface provide the highest load bearing capacity.

Statement of Problem: Oral lichen planus (OLP) is a cell-mediated immune condition for which several topical and systemic treatments are available.Purpose: The purpose of this study was to evaluate the efficacy of G2 vaccine on treatment of OLP.Materials and Methods: Ten OLP patients (7 females, 3 males) were enrolled in this study. Diagnosis of OLP was based on the clinical criteria and histological study. The patients received subcutaneous injection of 0.4 cc of G2 vaccine, once a week for twelve weeks. Oral symptoms before and after treatment were assessed by visual analogue scale. The data were analyzed, using student's t-test.Results: In this study, improvement in the lesion size was observed in the majority of the patients (good for 3 and poor for 5) while two patients showed no changes and no complete response was observed. The patients' symptoms (pain/burning) decreased significantly (p=0.01). The CD4+count and CD4+/CD8+ratio was increased after therapy.Conclusion: The present study indicated that the patients’ symptoms were decreased simultaneously with the increase in CD4+counts and rise in CD4+/CD8+ratio after inoculation of G2 vaccine. The findings suggest further studies with more sample size and also assessment of more types of cytokines for evaluation of the efficacy of G2 vaccine.

Statement of Problem: The most common oral fungal infection, denture induced stomatitis (DIS), is caused by the yeast candida, which is a normal flora of the digestive and vaginal tracts. Various predisposing factors have been associated with denture related stomatitis caused by candida albicans.Purpose: This study aimed to determine the prevalence of DIS and its predisposing factors in a sample of Iranian population admitted to Dental School of Tehran University.Materials and Methods: In this descriptive, analytical, and cross-sectional case series study 141 clinically healthy complete denture wearer patients attending dental school were enrolled through history taking and examination.Data about age, sex, denture age, dental hygiene habits, smoking habits and wearing at night were collected. Data analysis was undertaken on a computer, using SPSS 11.5; Phi test and crammers V test statistical methods were used.Results: In a total number of 141 patients, 38.3% showed DIS. There were 40.8% male and 35.7% female. There was no statistical relationship between age (p=0.117), sex (p=0.531), denture age (p=0.166), denture hygiene habits (p=0.144), and smoking habits (p=0.126) and the presence of DIS, but an association between wearing at night and presence of DIS was demonstrated (p=0.006).Conclusion: It is believed that wearing complete denture at night can increase the prevalence of DIS. Therefore, it is recommend that denture wearers be informed about the effect of dentures on the occurrence of denture induced stomatitis.

Statement of Problem: The origin of Dental Unit Water Lines (DUWL) contamination is specially related to the formation of biofilm which is composed of microorganisms within water and is located on the tubing lines.Purpose: In this descriptive study, we evaluated the degree of contamination with Gram positive and Gram negative bacteria in DUWLs of the dental school and also determined the efficacy of flushing on reducing its microbial count.Materials and Methods: Thirty dental units from all the departments of dental school in Tehran University of Medical Sciences were selected for this study. Sampling consisted of a two step procedure before and after one minute of flushing. The samples were taken from air/water line of each selected dental unit separately. Air/water syringe of each unit was completely disinfected with Deconex before sampling.Results: The range of the contamination varied from190 to 23×105 CFU/ml.The bacterial contamination included anaerobic Gram negativebacilli, nonfermenting Gram negative bacteria, Gram positivecocci and Gram positive bacilli. In all the samples taken from water taps, contamination was noted, varying from 25 to 1700 CFU/ml. This was significantly lower than the contamination of air/water syringe of the dental units.Conclusion: Applying the right principles for infection control such as using disinfectants or sterile water in dental settings and daily flushing before visiting patients can be of great significance.

The calcifying epithelial odontogenic tumor (CEOT), also known as the Pindborg tumor, is a benign and rare odontogenic tumor accounting for 0.4-3 percent of all odontogenic tumors. Few reports of the incidence of this tumor exist in Iran. The most frequent location is the mandibular premolar and molar area; less frequently the lesion is found in the maxilla.In clinical features, a painless slow-growing swelling will be seen. Microscopically large sheets of epithelial cells in few fibrous stroma, large areas of amorphous, eosinophilic hyalinized (amyloid-like) material and calcification in concentric rings formation within the amyloid-like material will be detected. The authors report a peculiar case of Pindborg tumor characterized by a rare localization of the lesion extending from anterior to the posterior of the upper jaw and by the young age of the patient.

A case of oral submucous fibrosis (OSF) occurring in a 15-year-old Iranian boy is reported. This case is associated with chewing of Supari for a long time.The close association between areca nut chewing and development of OSF with a risk of oral cancer has been demonstrated in many studies. There is no cure for OSF. Education and prevention seem to be the only way to reduce the risk of OSF. This article reviews the etiology, clinical presentation and treatment plan of OSF. This case reveals a correlation between the regular use of Supari (which contains areca nut) and OSF. This association has already been reported among Indian children but in Iran it has not still been reported.