Vol 14, No 4 (2017)

Original Article

  • XML | PDF | downloads: 244 | views: 522 | pages: 173-179

    Objectives: Pulpal inflammation is often associated with odontogenic pain. Dental pulp is abundantly innervated with sensory fibers encompassing neuropeptides. Neurokinin A (NKA) and substance P (SP) are important neuropeptides in the dental pulp that can cause neurogenic inflammation. Since no previous study has assessed dental pulp neuropeptides in children, this study aimed to compare the level of NKA and SP in gingival crevicular fluid (GCF) of sound and symptomatic carious primary teeth.
    Materials and Methods: Samples of GCF were obtained of 20 sound and 20 painful carious primary teeth. Enzyme-linked immunosorbent assay (ELISA) was used to quantify neuropeptides in GCF. Data were analyzed using paired t-test, ANOVA, Kolmogorov-Smirnov test and correlation coefficient test.
    Results: A significant difference was noted in the level of NKA in GCF of painful and sound teeth (2.23 pg/ml in painful, and 1.84 pg/ml in sound teeth, P<0.05). The difference between the two groups regarding SP was not significant (2.23 pg/ml in painful, and 2.02 pg/ml in sound teeth, P>0.05).
    Conclusions: The results showed that the level of NKA and SP was higher in GCF of painful teeth compared to that of sound teeth. This difference was statistically significant with regard to NKA. Thus, these neuropeptides can serve as indicators for pathological activities in teeth with symptomatic irreversible pulpitis.

  • XML | PDF | downloads: 233 | views: 389 | pages: 180-190

    Objectives: Oral health is an important aspect of general health and well-being for children. Understanding the viewpoint of mothers about children's oral health provides a basis for the development of interventions to improve oral care and disease prevention. The purpose of this study was to explore the perception of Iranian mothers regarding the oral health of their children.
    Materials and Methods: This descriptive qualitative study was the first phase of an exploratory mixed method design and collected data from April to May 2015 in Tehran, Iran. The qualitative data were collected through seven focus group discussions and three semi-structured interviews. The participants were 58 Iranian women who had a first grader. Data were analyzed using conventional content analysis.
    Results: The main themes identified from the data were: (I) the definition of oral health, (II) the importance of maintaining oral health and dental treatment, (III) the effect of nutrition on children’s oral health, (IV) the role of oral health behaviors, (V) the causes of dental caries and malocclusion/crowding, (VI) the symptoms and causes of gum disease, (VII) the causes of halitosis.
    Conclusions: According to the mothers' perception, the main factors influencing children's oral health were: nutrition and oral health behaviors such as daily tooth brushing and flossing. The results of this study can be used to develop a model of oral health education and a prevention program for improving oral health among Iranian school-children.

  • XML | PDF | downloads: 222 | views: 590 | pages: 191-202

    Objectives: Oral Squamous Cell Carcinoma (OSCC) is the most frequent oral cancer worldwide. It is known as the eighth most common cancer in men and as the fifth most common cancer in women. Cytogenetic and biochemical studies in recent decades have emphasized the necessity of providing an appropriate tool for such researches. Cancer cell culture is a useful tool for investigations on biochemical, genetic, molecular and immunological characteristics of different cancers, including oral cancer. Here, we explain the establishment process of five primary oral cancer cells derived from an Iranian population.
    Materials and Methods: The specimens were obtained from five oral cancer patients. Enzymatic, explant culture and magnetic-activated cell sorting (MACS) methods were used for cell isolation. After quality control tests, characterization and authentication of primary oral cancer cells were performed by short tandem repeats (STR) profiling, chromosome analysis, species identification, and monitoring the growth, morphology and the expression of CD326 and CD133 markers.
    Results: Five primary oral cancer cells were established from an Iranian population. The flow cytometry results showed that the isolated cells were positive for CD326 and CD133 markers. Furthermore, the cells were free from mycoplasma, bacterial and fungal contamination. No misidentified or cross-contaminated cells were detected by STR analysis.
    Conclusions: Human primary oral cancer cells provide an extremely useful platform for studying carcinogenesis pathways of oral cancer in Iranian population. They may be helpful in explaining the ethnic differences in cancer biology and the individuality in anticancer drug response in future studies.


  • XML | PDF | downloads: 191 | views: 507 | pages: 203-211

    Objectives: It has been demonstrated that polyphenol components such as silymarin and resveratrol have anti-inflammatory properties. Periodontitis is a chronic inflammatory disease that leads to the breakdown of dental supporting tissues and tooth loss. The purpose of this study was to investigate the anti-inflammatory effects of silymarin and resveratrol on lipopolysaccharide (LPS)-induced inflammatory response in human gingival fibroblasts (HGFs).
    Materials and Methods: HGFs were treated with different concentrations of silymarin and/or resveratrol (25, 50, 100 and 200μg/ml). The effects of silymarin and resveratrol on cell viability and proliferation were assessed by MTT assay and cell cycle analysis, respectively. Also, HGFs were treated with silymarin and/or resveratrol and were stimulated with LPS. The levels of Interleukin-6 (IL-6) and IL-8 were assessed by enzyme-linked immunosorbent assay (ELISA). 
    Results: After treatment with silymarin, the viability of fibroblasts significantly increased, whereas treatment with resveratrol did not have any significant effect on cell viability. However, the combination of these flavonoids (50µg/ml silymarin and 100µg/ml resveratrol) significantly increased the viability of fibroblasts. Resveratrol significantly inhibited LPS-induced IL-6 and IL-8 secretion by HGFs, but silymarin did not show such a significant effect.   
    Conclusions: The findings of the present study demonstrated the anti-inflammatory effects of resveratrol and its combination with silymarin. Therefore, the combination of silymarin and resveratrol may be useful as a therapeutic agent for treatment of periodontal diseases.

  • XML | PDF | downloads: 235 | views: 395 | pages: 212-223

    Objectives: This study assessed the efficacy of modified bioactive glass (MBG) for dentin remineralization and obstruction of dentinal tubules.

    Materials and Methods: Thirty-six dentin discs were made from 20 third molars and were stored in 12% lactic acid solution for two weeks to induce demineralization. The samples were divided into three groups (n=12): 1- BG, 2- BG modified with 5% strontium (Sr) and 3- BG modified with 10% Sr. After applying the BG, the samples were stored in artificial saliva for 7, 14 and 21 days. Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR), X-ray Diffraction (XRD) analysis, Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray (EDX) analysis were used to assess remineralization. Also, 6 dentin discs were divided into three groups of BG, BG modified with 5% Sr and BG modified with 10% Sr, to examine tubular occlusion. The discs were etched using 0.5M of EDTA for two minutes and were stored in artificial saliva for 7 days. Changes in dentin surface morphology were evaluated under SEM.

    Results: Group 3 showed high rates of remineralization at days 7 and 14, although the rate decreased at day 21. Group 2 exhibited high rates of remineralization at days 7, 14 and 21. Dentinal tubules were partially occluded by BG and BG modified with 5% Sr, while they were almost completely obstructed after the use of BG modified with 10% Sr.

    Conclusions: Strontium increases remineralization. Addition of 10% Sr to BG enhances apatite formation; however, the apatite dissolves over time. Addition of 5% Sr to BG stabilizes the apatite lattice and increases the remineralization.

  • XML | PDF | downloads: 173 | views: 318 | pages: 224-230

    Objectives: When a patient has cone beam computed tomography (CBCT) images based on the treatment plan, it is possible to use these images for evaluation of caries, and there is no need for new radiographs, according to the "as low as reasonably achievable" (ALARA) principle. The aim of this study was to determine the effect of filtration and thickness of CBCT cross-sections on detection of proximal caries.
    Materials and Methods: In this in-vitro study, 100 teeth were placed in the dental sockets of a dry skull, and were fixed in normal proximal contacts. CBCT images were taken and were evaluated by two observers on the panoramic view at 1-, 3- and 5-mm-thick cross-sections, with the use of filtrations 0, 1 and 2. Afterwards, the samples were sectioned and underwent a histological evaluation. McNemar’s test was used to compare the findings on CBCT images and histological evaluation. Receiver operating characteristic (ROC) curves and logistic regression were used to evaluate the diagnostic accuracy of different cross-sections.
    Results: The maximum AZ-value was achieved at 3-mm thickness/filtration 2. However, the differences between 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1 were not significant (P=0.728 and 0.868, respectively). The minimum AZ-value was achieved at 5-mm thickness/filtration 0.
    Conclusions: Although CBCT is not sufficiently effective in detecting caries, the best cross-sections for detection of proximal caries were achieved at 3-mm thickness/filtration 2, 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1.

  • XML | PDF | downloads: 226 | views: 318 | pages: 231-236

    Objectives: The purpose of this experimental study was to discover a method to increase the strength of repaired polymethyl methacrylate (PMMA) samples.
    Materials and Methods: In this experimental study, 40 specimens with the dimensions of 65×10×2.5mm3 were fabricated using heat-curing acrylic resin. Sixteen specimens were repaired with fiberglass and self-curing PMMA, while 16 samples were repaired with self-curing PMMA. Eight specimens were left intact as the control group. Afterwards, the flexural strengths of the repaired and intact specimens were measured by three-point bending test in a universal testing machine. Data were analyzed with one-way analysis of variance (ANOVA) and Tukey's HSD and LSD tests. The level of significance was set at P<0.05.
    Results: The mean flexural strength of the samples repaired with fiberglass was higher than that of the other repaired samples. However, the difference was statistically significant only with respect to the Meliodent group (P=0.008).
    Conclusions: Impregnated fiberglass could be used in the repair of denture bases to improve the flexural strength. In terms of the fracture site, it can be concluded that the lower flexural strength of the auto-polymerizing acryl compared to that of the heat-curing type was the main reason for the occurrence of fractures, rather than the weak bond between heat-curing and auto-polymerizing acrylic resins.

  • XML | PDF | downloads: 165 | views: 341 | pages: 237-245

    Objectives: Fluoride varnish application is an effective way to prevent caries in children. We aimed to educate preschool children’s mothers on how to apply fluoride varnish and compare their performance with dental students and to assess their self-reported competency six months later.
    Materials and Methods: Eighty-eight 4-6-year-old children presenting to toy houses of six randomly selected health centers in a non-affluent district of Tehran in 2014 were divided into two groups to receive fluoride varnish by their mothers and students. Mothers and senior dental students participated in a session consisting of lecture, discussion, and demonstration of fluoride varnish application for a child. Then, in three centers, mothers and in others, students applied fluoride varnish for preschoolers and their performance was evaluated. Six months later, mothers were asked to apply fluoride varnish again. Mann-Whitney U test, t-test, one-way ANOVA and logistic regression model were used for statistical analyses.
    Results: The mean performance score was 9.74±0.22 (out of 10) for mothers and 9.71±0.15 for students (P=0.89). After six months, the mean performance score was 9.58 for mothers, which was not significantly different from that in the first session. The age and educational level of mothers were conversely correlated to their performance (P<0.05). Of mothers, 96% believed that they were competent to repeat fluoride varnish application for their children.
    Conclusions: Mothers’ high performance score and the point that the majority of them felt competent to apply varnish for their children casts light on their potential key role in oral health promotion.