JOURNAL OF ISLAMIC DENTAL ASSOCIATION OF IRAN (MAJALLAH-I-DANDANPIZISHKI)
Year:2011 | Volume:22 | Issue:4 (77)|Papers Count:12

Background and Aim: Development of fluorosis is increasing due to the higher consumption of fluoride. Microabrasion is the most conservative technique for the management of this disorder. The present study assessed the esthetic improvement of fluorotic teeth after microabrasion with office bleaching.Materials and Methods: This clinical trial was carried out on 20 fluorotic teeth. Microabrasion was performed for 10 minutes followed by office bleaching. Digital images were obtained of all stages of the treatment. The esthetic improvement was determined by visual analogue scale along with the color parameters of L*a*b* and (DE) after microabrasion (M), microabrasion plus office bleaching (MO) and one week later the data were subjected to One-way analysis of variance (ANOVA) for repeated measures, LSD and Friedman tests.Results: No significant differences were found between fluorotic areas and non-fluorotic areas of the teeth after different stages of (M) regarding L*a*b* and DE parameters. The mean DE was estimated to be 10.05, 14.51 and 20.28 for M, MO and one week later, respectively. Significant differences were observed between these stages (p<0.001). In addition, the mean visual analogue scores for these stages were 4.15, 5.22 and 6.36, respectively, which were significantly different (p<0.0001).Conclusion: This study showed that the microabrasion technique significantly improved the esthetic appearance of fluorotic teeth at all stages of treatment. The most improvement was observed with (MO) after one week and the least was related to (M), while immediate results of (MO) were moderate.

Background and Aim: Streptococcus mutans and sanguinis are etiologic agents of dental caries. The use and search for drugs derived from plants have accelerated in the recent years. The aim of this study was to compare the antibacterial effects of ethanolic walnut leaf extract with chlorhexidine mouth rinse on these bacteria.Materials and Method: In this experimental study, after collection and extraction of the plant, the ethanol extract of walnut leaves together with chlorhexidin was examined for antibacterial activities on Streptococcus mutans and Streptococcus sanguinis using the agar-diffusion and microdilution methods. Amikacin (30µg) was used as an antimicrobial positive control. Assessment of total phenolic components was carried out using Folin-Ciocalteu method. Data were collected as a check list based on observation of laboratory results and analyzed by SPSS 16 software using the Man-Whitney statistical test.Results: The results showed that the Minimum Inhibitory Concentration (MIC) for ethanolic extract of walnut leaf was 125 and 15.6 mg/ml for Streptococcus mutans and Streptococcus sanguinis, respectively. There was significant different between ethanolic extract and chlorhexidine on the inhibition zone for Streptococcus mutans (p=0.000) but no significant difference was observed for Streptococcus sanguinis (p=0.058). Deal of the phenolic component was 410±14.43 mg/g.Conclusions: These findings showed that walnut leaves have antibacterial effects on these two bacteria and may be substitute for protection and treatment against dental plaque due to these microorganisms.

Background and Aim: Rotary files may be cause anatomical changes in apical area. The aim of this study was evaluation of maintenance of the canal’s curve using Flex Master and Protaper rotary instruments.Materials and Methods: In this in vitro study, we used 30 mesiobuccal roots of first permanent maxillary molars with a mean length of 18-23 milimeters and a mean curve of 15-40 degrees. Sampling was simple and the specimens were divided into two groups of fifteen. In each group, the canals were prepared by crown down method after the access step. Then they were prepared using Flex master and Protaper according to their company’s instruction. After finishing the preparation steps, hand instrument number 30 was placed in the canals and under the same primary condition we evaluated the final angle by digital radiographic system. For evaluation of the results, we used variance analysis, t test and covariance analysis.Results: The mean angle of apical transportation after using two Flexmaster and Protaper rotary systems was 6/19±3/07 and 5/52±2/87 degree, respectively. The mean apical transporation using the Flexmaster system was more than Protaper system but the difference between them was insignificant (P>0/ 05).Conclusion: Because of using these two rotary systems, we had apical canal transportation. This transportation by using Flexmaster system was more than the Protaper system, but it was not significant.

Background and Aim: Effectiveness of oral health promotion programs requires presence of knowledgeable and prevention-oriented dental workforce. The aim of the present study was to investigate attitudes of dental students and its determinants in Tehran towards prevention based on Hiroshima University-Dental Behavioral Inventory (HU-DBI) questionnaire.Materials and Methods: A Farsi version of HU-DBI questionnaire was prepared, validated and administered to the pre-clinical and clinical students of three dental schools located in Tehran. Chi-square test and logistic regression model served for statistical analysis.Results: In this cross-sectional study, two-hundred students participated. Women were less likely to agree with the statements "I have noticed some white sticky deposits on my teeth", and "I think I can clean my teeth well without using toothpaste" (P=0.04 and P=0.06, respectively), and more likely to agree with "I think that I cannot help having false teeth when I am old" compared to men (P=0.015). Differences related to the students’ schools also existed in the students’ reactions to the items "I have used a dye to see how clean my teeth are" and "I use a toothbrush which has hard bristles". Differences related to the students’ study year were also found in their attitudes towards prevention.Conclusion: Dental students’ prevention-oriented attitudes seem to be associated with their gender and study year. More emphasis should be placed on prevention in Iranian dental curriculum to overcome those differences in the students' attitudes which are related to background and academic characteristics.

Background and Aim: Prosthesis design has an important effect on its retention, especially in Resin Bonded Restorations (RBRs) in which preparation is conservative since there are different design possibilities to fabricate RBRs. The aim of this study was to compare the retention of RBRs with two different designs.Materials and Methods: In this experimental study, twenty-two RBRs were fabricated from twenty-two premolar and second molar teeth which had the same size and no carries. In the first group, conventional preparation which included lingual preparation, guiding planes, occlusal rests and two grooves in interproximal areas, was perfomed. In the second group, preparation included only class II inlay cavity preparation on the edentulous side. After frame work fabrication, the samples were cemented with resin cement (Panavia F), and subjected to tensile force. The force required to separate each sample was recorded and the results in the two groups were compared by t test.Results: Average retention in the group with conventional design was 39.523±8.62 kgf and 25.715±4.10 kgf in the group with modified design. The difference was shown significant by the statistical t test (P<0.001).Conclusion: Results indicate that the design with conventional preparation had a higher retention than the modified design that has only Class II intercoronal retainers.

Background and Aim: The wear resistance of composite denture teeth has been well investigated, but there have been few studies about the bonding of these teeth to acrylic denture base resins. The aim of this study was to evaluate the bond strengths of four brands of multilithic denture teeth to acrylic denture base material.Materials and Methods: In this experimental laboratory study four denture teeth groups (Glamour, Yaghout, Ivoclar and Apple) were used. Of each type of denture teeth 20 specimens were dogged into four wax prisms so that the lingual surface was faced upwards and the long axis of each of them made an angle of 90 degrees with the edge of the prism. After the placement of acryl and their curing stages, each sample was tested under shear-compressive force of 5 mm/min speed until fractured occurred. The data were analyzed by ANOVA and TUKEY test at 0.05 significance level.Results: Apple teeth had the highest mean bond strength (1337±414/99) followed by Yaghoot (1097/36±142/86), Ivoclar (945±366/43) and Glamour (880±285/80). Statistical analysis showed significant difference between the mean bond strength in some of denture teeth. Ivoclar specimens had the highest percentage of cohesive fracture followed by Apple, Glamour and Yaghoot. Nevertheless, statistical analysis showed no significant difference between the percentages of cohesive fracture in different groups of denture teeth.Conclusion: The results of this study showed that the bond strength of Apple denture teeth is more than Ivoclar and other denture teeth that were used in this stud.

Background and Aim: Fuji IX packable glass ionomer has anti-carious properties by adhesion to tooth structure. It seems to provide adequate seal between tooth structure and restoration due to the development of ionic crosslinks. Furthermore, bleaching may affect the marginal seal of restorations, subsequently increasing the leakage of oral fluids and bacteria into the restored structure. The aim was to evaluate the effect of packable glass ionomer (Fuji IX) on the microleakage of Class V restoration exposed with and without H2O2 35%.Materials and Methods: Forty sound human molars and premolars were selected and class V standard cavities were prepared on each tooth. The specimens were assigned in two case and control groups while cases were exposed to H2O2 35% for the subsequent 5 days (30 minutes each day thrice) and the controls were stored in serum physiology. The specimens were thermocycled, stained with fushin and sectioned longitudinally. The microleakage scores were determined and subjected to Mann-Whitney U and Friedman tests in both groups.Results: The mean and median of leakage scores in four regions of control specimens were 1.588 and 1.625 while the ratios were 1.913 and 2.25 for the teeth exposed to H2O2. The teeth exposed to H2O2 35% leaked higher than control specimens in the mesial region (p<0.04), while no significant differences were observed between two groups in the other areas.Conclusion: The use of Fuji IX glass ionomer cements in the restoration of class V cavities is an acceptable treatment modality for the restoration of bleached teeth.

Background and Aim: One of the most important side effects of frequent hemodialysis is xerostomia. Therefore, this study compared saliva secretion caused by a specific saliva stimulant chewing gum (Bioten) with an ordinary sugar free one (Orbit) on hemodialysis patients.Materials and Methods: This study was a clinical, double-blinded cross-over study. Thirty volunteer hemodialysis patients of two dialysis centers in Isfahan were randomly classified into two groups. In the first period of 14 days, each group was given one brand of chewing gum (Biotene or Orbit) to chew. Three gums a day of each brand were given to each group to chew for at least 10 minutes, while the other group was given the other brand. After a one- week-washout period in between, the second 14 days period was accomplished by changing the brands of chewing gums given to each group. Before the beginning of the study and after each period, the secreted saliva was measured. The findings were statistically analyzed using the t test and Wilcoxon test.Results: Chewing each kind led to a considerable increase in saliva secretion and achieved patient satisfaction (p<0.05) while the efficacy of Bioten was significantly higher (p<0.001). Regarding the patients’ overall satisfaction about the effect of the chewing gums on reducing xerostomia, most patients chose Bioten (p<001).Conclusion: Both kinds of chewing gums were effective in increasing saliva secretion. However, the effect of Bioten was more significant.