Avicenna Journal of Dental Research
Volume:2 Issue: 2, Jan 2010

The first reaction between food components and biological tissues occurs in the oral cavity. Saliva modulates the ecosystem in the oral cavity and plays a critical role in oral homeostasis. In addition, saliva is a first line of defense against free radical-mediated stress. Salivary antioxidant defense mechanisms seem to be very important. In this study we discuss in detail free radicals (FR) and reactive oxygen species, oxidative stress, oxidative stress and disease, antioxidants, factors influencing antioxidant efficacy and level, antioxidants and disease prevention, antioxidants and disease treatment, classification system and finally salivary antioxidants.

Statement of the problem: Melatonin has powerful antioxidant effects, has an immunomodulatory role, stimulates the synthesis of type I collagen fibers, and promotes bone formation. Melatonin is also secreted in the saliva, although its role in the mouth is not known well. The aim of this study was to examine the correlation between salivary melatonin level and periodontal diseases. Fifty subjects with a mean age of 40.44±6.38 years were equally divided into 5 groups: 10 healthy subjects, 10 subjects with gingivitis, 10 subjects with localized moderate chronic periodontitis, 10 subjects with generalized moderate chronic periodontitis and 10 subjects with generalized severe chronic periodontitis. Saliva samples were collected from all the subjects and melatonin levels were determined using an enzyme-linked immunosorbent assay. Two-way and one-way ANOVA and Tukey test were used to analyze relationships between the variables. Healthy subjects had significantly higher salivary melatonin level (5.29±0.50 pg/mL) compared to patients with gingivitis (4.35±0.30 pg/mL) (P<0.001). The difference between salivary melatonin level in patients with gingivitis and periodontitis was significant (P<0.001). Level of melatonin in patients with generalized severe chronic periodontitis (3.39±0.10 pg/mL) was significantly lower than that in other groups (P<0.01). This study showed that salivary melatonin level in patients with periodontal diseases is lower than that in healthy subjects, and it has a negative correlation with the severity of disease, suggesting that melatonin might have a protective role against periodontal diseases, although further research is required to validate this hypothesis.

Statement of the problem: Removal of impacted third molars is the most common oral surgical procedure. Many investigators have questioned the necessity of removal in patients who are free of symptoms or associated pathologies. There are currently no data on the prevalence of impacted teeth and associated pathologies in the Hamadani population. The aim of this study was to assess the status of impacted teeth and to determine the frequency and type of pathological conditions associated with these impacted teeth. This study included 900 patients who were referred to Department of Oral and Maxillofacial Radiology, Hamadan Dental School for panoramic radiography. The age range of the patients was 14?70 years. Clinical and radiographic examinations were carried out. The angulations of impaction, caries and root resorption of the adjacent teeth and increase in the pericoronal space were determined. A total of 162 patients presented with at least one impacted tooth and 72 patients presented with at least one semi-impacted tooth. Male to female ratio was 3.9 to 3.3. Among the impacted teeth, mandibular and maxillary third molars were the most common (80%), followed by maxillary canines (18%). Approximately 4% of teeth adjacent to impacted and semi-impacted teeth had root resorption. Carious lesions were also found on the distal surface in approximately 3% of second molars. Pathological lesions were found in approximately 4% of impacted and semi-impacted teeth. The prevalence of impacted teeth was high, and there was a predilection for impacted third molars in the mandible. Caries, root resorption and pathological lesions were seen in relation to the impacted teeth

Statement of the problem: In recent years, amalgam has been considered a danger for dentistry personnel due to toxicity of mercury (Hg). This study aimed at investigating the relationship between scientific indices and dentists’ urine Hg level through measuring its concentration rate among dentists with over four years of experience. Thirty dentists with over four years of experience in clinic completed a questionnaire related to practical indices such as working time in clinic, the number of amalgam restorations, waste disposal methods, the number of amalgam repair finishes per day, and the number of amalgam-repaired teeth in dentists’ oral cavity. Thirty urine samples were collected from the participants and the urine specific weight was measured on the same day with a refractometer. After completion of preparation stages, Hg was extracted from the upper organic layers of the solution by potassium bromide and measured by a spectrophotometer at a wavelength of 48 nanometer in µgHg/L. Urine creatinine of each sample was measured and the Hg concentration obtained was divided by creatinine concentration. The urine Hg values were reported in terms of µg Hg/gr.cr. Data were analyzed by t-test, Pearson’s correlation coefficient and linear multi-variate regression test. The urine Hg level rate was 31.62–in average lower than admissible threshold level. Totally, 11 samples were greater than threshold level. Among the practical indices in the study, the method of cleaning amalgam-contamionated instruments, the method of amalgam waste disposal and the number of restorations carried out showed a significant relationship with urine Hg level (P< 0.05). The number of restorations carried out plays an important role in determining urine Hg levels.

Statement of the problem: Dental gloves are worn to protect dental care providers from contamination during contact with mucus membranes, blood and saliva. The prevalence of latex allergy has progressively increased due to the widespread use of protective disposable wears, especially latex gloves, among health care workers (HCW) in the past decade. The prevalence of latex allergy among HCW of Iran is not clear. On the other hand, the rate of sensitivity of sensitive dentists to other allergens is unknown. The aim of this study was to evaluate prevalence of latex allergy among a selected population of Iranian dentists and its association with allergy to other dental materials. A total of 140 dentists who worked in the clinics and offices were evaluated in this cross-sectional/descriptive study. The dentists were asked to fill out a questionnaire concerning the allergy history. Fisher’s exact test was used for testing the relation of variables. The Microsoft Excel and SPSS for Windows 16.0 were used for data analysis. Based on questionnaires, 45 dentists (33.8%) had hypersensitivity to latex gloves. Hypersensitive dentists to latex gloves were also hypersensitive to non-powdered gloves, temporary crowns and impression materials. Regarding other materials, there was no significant difference between the two groups. It is recommended that the subjects who are susceptible to latex allergy based on the questionnaire be referred for skin tests.

Statement of the Problem: The incidence of infectious diseases is considerably high among dentists and the team of dental care providers because of frequent exposure to blood and saliva. Therefore, infection control regulations must be taken seriously in order to prevent cross-contamination. The aim of the present study was to investigate infection control measures in dental offices in Hamadan, Iran in 2010. In this descriptive cross-sectional study, 77 general and 54 specialized dental offices provided information in terms of the level of infection control measures. The information was obtained via observation and questionnaire. The questionnaire was compiled in eight sections, including the environmental safety and building characteristics, the dental unit, the accessories, instruments, materials, environmental protection, personal protection and infection control behaviors and disposing the wastes. Data were analyzed using chi-squared, Mann-Whitney U and Kolmogorov-Smirnov tests and comparisons were made between the general and specialized dental offices. Infection control statuses in the general and specialized dental offices in relation to the dental unit were 23.09% and 76.22%; in relation to instruments they were 67.34% and 95.57%; and in relation to personal protection they were 58.50% and 64.42%, respectively. Infection control measures revealed significant differences between the general and specialized offices in relation to all the aspects except the personal protection measures (P<0.05). This study demonstrated that specialized offices were more successful in implementing infection control measures; however, there is room for improvement and further education and supervision is required to reach the optimum level of standards.

Statement of the problem: Subgingival irrigation with an antimicrobial agent after scaling and root planing (SRP) is assumed to be able to kill the bacteria left behind after mechanical debridement. 3% H2O2 is used in the treatment of periodontal disease and it has been shown effective in killing anaerobic pathogens. The aim of this study was to evaluate the clinical effects of subgingival irrigation of periodontal pockets with 3% H2O2. Thirty-five patients with probing depths of 3?5 mm were selected for the study. All the oral cavity sites were scored at baseline and on days 21 and 35 for these periodontal indices: gingival bleeding on probing, probing depth, and attachment level. The pockets in various quadrants were randomly assigned to professionally performed subgingival irrigation with 3% H2O2 or saline or to non-irrigation groups on baseline and days 7 and 14 after the first step of therapy with SRP and oral hygiene instruction. The results showed that subgingival irrigation with 3% H2O2 produced a significant reduction in gingival bleeding index compared to the control while there were no significant differences between the 3 groups in probing depth reduction. Irrigation with H2O2 also resulted in a significant reduction of attachment levels between the 3 groups on day 21. The results of the present study indicate that subgingival irrigation with 3% H2O2 plays a potential role in inflammation control and reduction of gingival bleeding

Cemento-ossifying fibroma is a fibro-osseous lesion that has benign neoplastic behavior. We report two cases of cemento-ossifying fibroma (COF) and review the literature in order to study the imaging findings of COF. It is almost unavoidable that diagnosis of fibrous dysplasia from COF will be complicated by the fact that some pathologic features are shared by both lesions. So the final definitive diagnosis requires evaluation of the radiographic features.