مجله تحقیق در علوم دندانپزشکی
سال هفتم شماره 4 (پیاپی 26، زمستان 1389)

Cell-titanium interactions are crucial to the clinical success of bone and dental implants. Mechanical or chemical surface treatment can help the cell attachment to implant surface. The purpose of this study was to investigate the effect of two distinct surface treatment(sandblasted and acid-etched) on fibroblasts cell attachment and viability. In this experimental study the fibroblasts behavior was analyzed on three different titanium surfaces: sand blasted(SB), Acid-Etched (AE)and pure commercial titanium(PCT), in three groups,(N=10). Scanning electron microscopy (SEM) showed distinct microtopographies. Cell morphology and initial attachment were evaluated by SEM. Cell viability was measured by means of a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The number of viable cell counts were compared using one way ANOVA Test. SEM observation revealed drastic differences in surface microtopography, with a higher cell density on (SB)than (AE)and(PCT). Cell attachment were much better in the sand-blasted group than others. Cell viability recorded by the sand-blasted group(1.28±0.58) was significantly better than acid-ethed (0.95±0.23) and pure commercial titanium(1.67±0.17).(P < 0.05) Implant surface treatments influence the attachment and viability of fibroblasts(L-929), and sand-blasted treatment seems to be the most favorable surface to compare with acid-etched and and pure commercial titanium surface.

Aerosols containing microbes from the oral cavity of the patient are created by using high-speed rotating instruments while practicing dentistry. This study aimed to evaluate the level of microbial aerosol contamination in different dental departments of IslamicAzad university,Dental branch in 2009. A cross sectional study has been carried out on184 samples of 3- 6 location of 11 departments from operatory and non-operatory places.The samples were cultured on blood agar plates that was placed one meter height from the floor. In each section, a control agar plates were placed in non operatory part. Anaerobic microbes was not evaluated, Prevalence of contamination was evaluated and role of related factors: traffic sector, service type, time, or the use of turbines, the volume of space and number of units were analyzed by Fisher's exact test and DOE (Design Of Experiments). Aerosol containg microbes have been observed in% 88 of the samples. The air contamination in the therapeutic section was 47.3% and in non- therapeutic section was 52.7%. Microbes found in the same sectors, including gram-positive cocci %58.5, gram-negative cocci% 25.8, gram-positive bacilli %12, fungi %2.1,gram negative bacilli %6.1. Microbial air pollution levels in non- health sectors in the morning and with fewer patients had increased significantly The results shown high degree of contamination which is striking. According to AMI standard, the results shown high contamination rate, therefore the need for developing new means for preventing microbial aerosols is mandatory.

Discoloration of dental composites is one of the major reasons of their change which can be influenced by internal and external factors. The aim of this study was to evaluate discoloration susceptibility of two Nanofilled and Micro hybrid composites by coffee and tea. This experimental study was carried out on 30 composite specimens of Point 4 and Premise. The specimens were divided in 6 groups (n=5). After primary color measurement by spectrophotometer the specimens were stored in distilled water, coffee and tea for one week and then the color was measured. Color changes (ΔE) were calculated. The data were analyzed by Two –way ANOVA,student T-test and Post Hoc Tukey test. The color change in both medius was significant for both composite groups. The effect of coffee and tea on discoloration of two composites was significant (P<0.05). There was no significant difference between the color change of the two composites. Also there was no significant Color changes of two composites point 4 and Premise by tea and coffee were clinically significant.

Inappropriate antibiotic's prescription by dentists has caused several worldwide problems in recent decades. Antibiotics are the most commonly medicine that prescribed by dentists. Inappropriate antibiotic's prescription causes: Development of simultaneous infections, mutations, genetic transmissions and bacterial resistance to antibiotics. The purpose of this study was to evaluate dental student’s attitude toward antibiotic therapy in endodontic treatments in Tehran's dental universities in 2009. In this descriptive study, 203 dental students selected by random from Tehran's dental schools. All interviewed students passed theoretical endodontic courses. Validity and reliability of the designed questioner assessed by following tests: Lawshe test (CVR=0/4), Cronbach Alpha Coefficient (0/8) and these tests approved by 3 psychiatrists. The results evaluated by Chai X2 test. The attitude of students regarding antibiotic therapy in endodontic treatments was as follow: completely incorrect (0%), completely correct (15.2%), correct (62.2%) and incorrect (22.6%). According to the results of the present study, there was no ideal point in dental student's attitude toward antibiotic therapy in endodontic treatments.

Tooth eruption is complex process that involves different mechanisms. Low birth weight (LBW) infants are prone to many serious medical problems during the neonatal period which may affect the development of oral tissues. The aim of this study was to evaluate the relationship between the birth weight and eruption time of the first primary tooth. We have conducted a cohort study of 70 full term infant (35 low BW, 35 Normal BW). This study was conducted in Al-Zahra hospital of Rasht-Iran in 2007. The infants observed periodically since 3rd month of birth until the first tooth eruption. X2 test has been used for comparison of the two groups and since month 8th the regression logistic test to determine the effect of relative birth weights risks and other variables in tooth eruption. The first erupted tooth was mandibular central incisor with (8.26±2.72) month in case group and (7.76±3.18) month in control group and there was no statistical difference between two groups, The first deciduous tooth had erupted in 51.4% of LBW and 42.9% of NBW infants until 8 months Relative risk of delay eruption after 8 months in LBW infants was 1.2.(RR=1.2). Birth weight in full term infant wasnt influence on the first deciduous tooth eruption time.

Oral health status could be affected the quality of life, hence recognition of related variables, might be a significant aid in recognition of biological, functional and psycho-social aspects of oral diseases. The aim of this study was to evaluate oral health status of 30-45 years old individuals and its affects on their quality of life. In this descriptive study 150 people referring to khorasgan dental branch, Isfahan Islamic Azad University, were selected. Oral health status was measured by DMFT and CPITN indexes according to WHO. Also quality of life in regard to oral health was measured with DIDL index, data was analyzed by Mann- whitney test and Pearson coefficient test. The average score and standard deviation of DMFT, CPITN and DIDL were 12.27 ± 6.79, 0.36 ± 0.5, 0.52 ± 0.6 respectively. Average score of restoration numbers in woman was higher than men.CPITN in men was higher than women. With decreasing socio-economic class, DMFT and CPITN indexes were increased and quality of life was decreased. According to the results of this study, there is a significant relation between DMFT, CPITN, and socio- economic factors and the quality of life.

Dental caries is the most common chronic disease in relation to sugary items. So the purpose of this study was to find the relationship between food intake and dental caries in 6-11-Year-Old children. This study was descriptive with random selection on 203 children. Data collection techniques were interview, clinical examinations and completing the food frequency questionnaire and information form. Consumption of food groups and basis information compared with dental caries prevalence, severity of dental caries in whole teeth and DMFT/dmft index separately. Quantitative and qualitative Data analyzed with appropriate tests and with the use of SPSS software, version 16. The frequency of using dried fruit, salty snack and confectionary group’s with dental caries prevalence and sugar, salty snack and confectionary group’s with severity of whole teeth decay showed a significance relationship(P<0.05). The frequency of using sugar and pastry group’s and snacks during the day had a positive relationship with DMFT/dmft index and dairy group had the negative relationship (p<0.01). Using of afternoon snack, snacks during the day and sugar group had a positive correlation and brushing teeth during past 6 months, and mothers education had a negative correlation with DMFT/dmft index (p<0.01). The main factor in incidence of dental caries were frequency of using sugary, sugary-starch foods, foods that stick to the teeth and irregular brushing (at least once a day).

Recurrent aphthous stomatitis (RAS) is a common oral mucosal disorder characterized by recurrent and painful oral aphtous ulcers. Although the exact cause of RAS is not known, but local trauma, nutritional deficiencies, hormonal changes, genetics, and immunologic factors have been suggested to contribute to its pathogenesis.The aim of this study was to assess the serum level of vitamin E in patients with RAU and normal subjects. This case-control study was conducted on19 patients with RAU and 17 healthy controls with same age and sex. Serum level of vitamin E was measured in both groups by liquid chromatography technique. Data were analyzed by Mann - u-Whitney test. The mean serum level of vitamin E was 14.89 ± 2.3 µg/ml in RAU patients and 22.53 ± 3.7µg/ml in normal group. This level was significantly lower in patients with RAU than in healthy control subjects (p<0.05). The present study demonstrated that serum level of vitamin E significantly decreased in patients with aphtous ulceration.

Benign oral fibrous histiocytoma is a rare lesion in the head and neck region. This tumor usually presents as a single nodular, painless mass which grows slowly and varies in size from 2- 3 cm to over 10 cm. Most patients are under 50 years of age and a history of trauma, chronic infection and sun exposure are reported. Case Report : In this paper a case of benign fibrous histiocytoma in the tongue of a 44 - year-old man is reported. In microscopic view spindle cell Fascicules, along with infiltration of multinucleated giant cells was presented and for definitive diagnosis immunohistochemistry staining for SMA,, Desmin, MSA, CD68 and CD34 was conducted. Microscopic feature of oral fibrous histiocytoma may be similar to some soft tissue tumors. Therefore, IHC is necessary for definite diagnosis.