فهرست مطالب

Dental Research Journal
Volume:17 Issue: 3, May-June 2020

  • تاریخ انتشار: 1399/04/23
  • تعداد عناوین: 11
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  • Vishwendra Singh*, Gurvanit Lehl Pages 167-173

    Child abuse, a reprehensible act, pervades all strata of society. Dentists are more likely to encounter such cases in their daily practice. However, such cases usually go unreported due to lack of adequate knowledge. Practitioners flinch from reporting these due to various reasons, and this sets up a vicious cycle which traps the victim leading to grave long‑term consequences. This review aims to collect all literature available on PubMed, PubMed Central, MEDLINE, Google Scholar, and Google search engines on the role of dentists in child abuse identification and information and summarize these details. The review will shed light on the identification of abuse in dental settings, the various legal recourses and organizations related to it, and how dentists can better equip themselves to tackle such cases if they come across one. The review also makes certain recommendations by which dentists and healthcare providers in general can better prepare themselves for such contingencies.

    Keywords: Child abuse, dental, India, laws
  • Atefeh Akhani, Arash Motaghi, Maryam Ostad Sharif, Simin Hemati Pages 174-178
    Background

    Oral squamous cell carcinoma (SCC) is the most common oral malignancy. Some evidence indicated that there is a correlation between microRNA single nucleotide polymorphisms and the risk of oral cancer. The aim of the current study was to investigate the association between mir‑499 polymorphism with the risk of oral cavity and oropharyngeal SCC in a subset of Iranian Population.

    Materials and Methods

    In this case–control pilot study total of 112 participants including 56 histopathlogically confirmed oral and oropharyngeal SCC patients and 56 age‑ and sex‑matched controls were included The mir‑499 rs3746444 T/C polymorphism was detected using polymerase chain reaction‑restriction fragment length polymorphism method. The comparisons of the distribution of the allele and genotype frequencies were performed using Chi‑square test, and P < 0.05 was considered as statistically significant.

    Results

    The result of the present study indicated that the frequency distribution of mir‑499 was not significantly different between cases and controls (P > 0.05). We also did not find any significant association between the risk of the cancer and mir‑499 polymorphisms in the recessive (Odds ratio [OR]: 6.60; 95% confidence interval [CI]: 0.77–56.74; P = 0.11) and dominant (OR: 1; 95% CI: 0.37–2.74; P = 1) inheritance models even after adjustment for smoking.

    Conclusion

    The results of the present study indicated that the polymorphisms of mir‑499 are not associated with the risk of oral and oropharyngeal SCC in Iranian population. However, further large scale studies are needed to validate our findings.

    Keywords: Head, neck squamous cell carcinoma, microRNA, polymorphism
  • Zahra Golestannejad, Faezeh Khozeimeh*, Reihaneh Abtahi, Zahra Zarei, Leila Sadeghalbanaei, Rastin Sadeghian Pages 179-185
    Background

    Usage of chemical mouthwashes for controlling dental caries can end to some side effects such as oral biological imbalance. Recently, using natural derivatives such as herbs, presented to overcome such adverse effects. Due to antibacterial property of olive leaf extracts (Olea europaea), this study conducted in order to evaluate bacteriocidal, anti‑acid production, and anti‑adhesion effects of olive leaf ethanolic, methanolic, and hydroalcoholic extracts on Streptococcus mutans.

    Materials and Methods

    In this in vitro study, nine strains of S. mutans (PTCC1683) were used. Maceration methods were done in order to provide the olive leaf ethanolic, methanolic, and hydroalcoholic extracts. The antibacterial activities evaluated by macrodilution and disc diffusion method in different concentrations (3.25%–100%). Acid production and adhesion of bacterial strains also were evaluated. The obtained data were analyzed by analysis of variance method using SPSS software. P < 0.05 was considered as statistically significant.

    Results

    The minimum inhibitory concentration and minimum bactericidal concentration for ethanolic, methanolic, and hydroalcoholic olive leaf extracts on S. mutans are 12%–25%, 50%–75%, and 12%–25%, respectively. In addition, inhibition zone of S. mutans significantly increased in higher concentration (ethanolic and methanolic extracts: P = 0.004; hydroalcoholic extract: P = 0.003). The acid production and adhesion significantly decreased by increase in the concentration (P < 0.001).

    Conclusion

    In general, olive leaf ethanolic, methanolic, and hydroalcoholic extracts induce growth inhibition, acid production, and adhesion of S. mutans. Consequently, it can be used as a natural preservative in the food industry, as well as in the production of commercial products such as chewing gum, chocolate, and toothpaste to prevent dental caries.

    Keywords: Bacterial adhesion, microbial sensitivity tests, Olea, Streptococcus mutans
  • Behnaz Ebadian, Mahsa Abbasi, Arezoo Mazaheri Nazarifar Pages 186-192
    Background

    Temporomandibular disorder (TMD) is a common condition affecting the temporomandibular joint and causes pain and discomfort. However, the role of factors contributing to this problem is still controversial. The purpose of this cross‑sectional study was to determine the correlation of occlusal factors and parafunctional habits with TMD and The determination of TMD prevalence among patients referring to Isfahan Dental School in 2017.

    Materials and Methods

    In this cross‑sectional study, A total of 200 patients between 20 and 50 years were examined and questioned based on the Research Diagnostic Criteria for Temporomandibular Disorders assessment instrument. The association of occlusal factors (dental relationship, lateral occlusal scheme, horizontal differences between centric occlusion and Maximum intercuspation (MI), difference between MI and mandibular resting position) and parafunctional habits (bruxism/ clenching and habits) with TMD was analyzed using Chi‑square tests and independent sample t‑test (α = 0.05). Binomial logistic regression analysis was performed with respect to confounding variables.

    Results

    The prevalence of TMD in the studied sample was 58.9%. Only bruxism showed a significant difference between TMD and non‑TMD groups (P < 0.05). Other parafunctional and occlusal factors did not act as influential factors for TMD.

    Conclusion

    Parafunction may play an important role in the initiation of TMD, although other habits and occlusal factors are considered as noninfluential factors. However, larger sample size and multicenter sampling are recommended for the future studies.

    Keywords: Occlusion, prevalence, temporomandibular joint disorders
  • Ashwini Dessai, Neeta Shetty*, N. Srikant Pages 193-199
    Background

    Dentin hypersensitivity is primarily caused due to patent or exposed dentinal tubules. Nonfluoridated‑desensitizing agents deposit hydroxycarbonate apatite (HCA), within the dentinal tubules, thereby relieving hypersensitivity. Fluoride‑containing bioactive glass‑based agents form fluorapatite which is less soluble when compared to hydroxyapatite and HCA.

    Materials and Methods

    In this in vitro study forty dentin specimens obtained from extracted human premolars were divided randomly into four groups (n = 10): Group 1 – fluoridated bioactive glass (FBaG); Group 2 – bioactive glass (BaG); Group 3 – arginine calcium carbonate; Group 4 – saline. 37.5% phosphoric acid was used to ensure patent dentinal tubules. Test agents from each group were applied using a rubber cup. Half the treated samples were then subjected to 6% citric acid treatment. The degree of occlusion was evaluated using the scanning electron microscope, and the microscopic images were scored before and after the citric acid challenge by two blinded endodontists. Statistical analysis was performed using SPSS, one‑way ANOVA, and post hoc Tukey test (P = 0.05).

    Results

    Group 1 demonstrated better tubule occlusion in comparison with Group 2 and a statistically significant difference when compared to Group 3 (P = 0.001). Following acid challenge, Group 2 showed significantly more occluded tubules when compared with Group 3 (P = 0.001) and comparable difference with Group 1.

    Conclusion

    All desensitizing agents showed satisfactory dentinal tubule occlusion. While fluoridated bioactive glass demonstrated better occlusion immediately after application, Bioactive glass showed better resistance to acid treatment.

    Keywords: Bioactive glass, dentin hypersensitivity, scanning electron microscopy
  • Koosha Gholamrezaei, Fariborz Vafaee, Behzad Fathi Afkari, Farnaz Firouz*, Mozhgan Seif Pages 200-207
    Background

    This study aimed to assess the marginal adaptation and internal fit of cobalt‑chromium copings fabricated by the selective laser melting (SLM) and conventional techniques using a profilometer.

    Materials and Methods

    In this in vitro study sample size was calculated to be a total of 10 in two groups (n = 5). A brass model was used that had a circular cross‑section with a round shoulder margin with 0.5 mm thickness and axial walls with 10 mm length and 6° taper. The copings fabricated with both techniques (SLM and casting method) were placed on the model, and vertical marginal gap was measured using a profilometer. The internal fit of copings was assessed by weighing the light‑body addition silicone applied inside them, which simulated the cement. Data were analyzed through parametric (Independent t‑test) and nonparametric (Mann–Whitney U‑test, Bootstrap, Spearman, and Pearson Correlation) analysis. All analyses were performed at a significant level (α = 0.05) using SPSS.

    Results

    The mean marginal gap in the casting group (132.93 ± ) was significantly higher than that in the SLM group (67.14 ± 15.67 µm) (P < 0.05). The mean weight of light‑body silicone was 9.60 ± in the SLM and 8.70 ± 1.21 mg in the casting group. No significant difference was noted between the two groups regarding the internal fit (P > 0.05).

    Conclusion

    The copings fabricated by the SLM technique showed a smaller vertical marginal gap compared to the casting group. However, the two groups were not significantly different in terms of internal fit.

    Keywords: Dental marginal adaptation, dental prostheses, laser, prosthesis fitting
  • Majid Mirhashemi, Narges Ghazi, Nasrollah Saghravanian*, Ali Taghipour, Farnaz Mohajertehran Pages 208-212
    Background

    Squamous cell carcinoma (SCC) is the most common cancer of the oral cavity and may be preceded by dysplastic epithelial lesion. Oral SCC (OSCC) contains a rare subset of cancer cells with self‑renewal ability, termed as cancer stem cells (CSCs). CD24 and CD44 as CSC markers are cell surface glycoproteins. These markers contribute to the onset, maintenance, and extension of tumor growth, as well as angiogenesis. In the present study, these two markers were simultaneously evaluated to provide a specific phenotype for carcinogenesis process in oral cavity.

    Materials and Methods

    In this analytical‑cross‑sectional study, the expression of CD24 and CD44 genes was evaluated in 45 OSCCs (20 low‑grade and 25 high‑grade) and 15 oral epithelial dysplasia specimens by real‑time quantitative reverse transcription polymerase chain reaction. Kruskal–Wallis and Mann–Whitney U‑test, Kendall, and Spearman tests were used for statistical analysis. The significance level was considered <0.05.

    Results

    High expression of both markers genes was reported in two‑thirds of samples. There was no significant difference between studied groups in gene expression of CD24 and CD44 whereas statistically significant association between CD24 and CD44 was observed in all three groups. This correlation was more significant in OSCC groups (P < 0.001).

    Conclusion

    High expression of CSC markers in OSCC and oral epithelial dysplasia revealed the importance of accurate examination of dysplastic lesions with high expression of these markers and the possibility of malignant transformation. Regarding a significant association of two markers, further studies are necessary to provide a specific phenotype (CD44 high CD24 high) for these lesions.

    Keywords: Carcinoma, polymerase chain reaction, squamous cell
  • Alireza Dehdashtizadeh, Nasim Esnaashari, Shirin Zahra Farhad*, Fatemeh Ejeian, Shaharam Amini Pages 213-218
    Background

    Periodontal ligament fibroblasts (PDLF) play a key role in periodontal wound healing and tooth‑supporting structures. Various approaches have been tried to enhance the fibroblastic activity such as laser irradiation or doxycycline application. The current study explored the influence of laser irradiation and doxycycline application on human PDLF. The aim of the study was the effect of low‑level laser treatment and doxycycline application on the expression of collagen I and matrix metalloproteinase‑8 (MMP8) from cultured human periodontal ligament cells.

    Materials and Methods

    In this experimental study After preparation of human PDLF in three replications, they were divided into five treatment groups. The first group was day 0, which was used for standardization. The second group was the control group, which received no treatment within 4 days of the study. The third group was treated with doxycycline 30, µm cc daily for 4 consecutive days. The fourth group was treated with diode laser 2 J cm2 daily for 4 consecutive days. The fifth group was treated with both doxycycline and laser irradiation pertaining to the third and fourth groups. After 4 days of treatment, cells were tested for collagen I and MMP‑8 secretion through real‑time‑polymerase chain reaction and ELISA reader. The data were analyzed using the ANOVA and least significant difference pair tests ( P < 0.05 ).

    Results

    Treatment of human PDLF either with diode laser or doxycycline reduced the secretion of MMP‑8 significantly. The maximum reduction was related to doxycycline application. Regarding collagen, I, only doxycycline application significantly increased collagen I secretion. Other groups showed no significant increase in collagen I secretion.

    Conclusion

    This study showed that treatment of human PDLF either with diode laser or doxycycline significantly reduced MMP‑8. Treatment with doxycycline significantly increased the secretion of collagen I.

    Keywords: Collagen, diode laser, doxycycline, matrix metalloproteinases‑8
  • Shiva Alavi, Farnaz Asadi, Seyed Amir Hossein Raji, Soroor Samie* Pages 219-224
    Background

    Titanium miniscrews are used at an ever‑increasing rate to provide orthodontic anchorage. The aim of this study was to evaluate the mechanical performance of miniscrews after dry and steam sterilization.

    Materials and Methods

    In this experimental study, a total of 72 miniscrews from two different manufacturers with a diameter of 1.6 mm and height of 8 mm were divided into six groups (n = 12). One group of screws from each manufacturer was considered as the control group; the second underwent steam sterilization; and the last group was subjected to dry sterilization. Insertion and fracture torques of each miniscrew were assessed by a torque tester. Data were analyzed using the Kruskal–Wallis and Mann–Whitney tests (P < 0.05).

    Results

    For Jeil miniscrew, no statistically significant differences were detected between the steam‑sterilized and control groups in their insertion torques (P > 0.05). There was a statistically significant difference between the steam sterilized, dry sterilized and control groups with respect to their fracture torque (P < 0.001). For Hubit miniscrew, there were no significant differences between steam sterilized, dry sterilized and control groups in their insertion torque (P > 0.05) and between steam sterilized and control groups with respect to their fracture torque (P > 0.05). There were significant differences in the mean values of insertion and fracture torques between the two different manufacturers (P < 0.001).

    Conclusion

    Steam sterilization had no detrimental effects on torque values of miniscrews, but dry heat sterilization affected their mechanical properties.

    Keywords: Anchorage technique, orthodontic, sterilization, torque
  • Saeed Nezafati, Mohamadali Ghavimi, Reza Javadrashid, Sina Farhadi, Vahid Dehnad* Pages 225-230
    Introduction

    Ultrasonography (USG) allows to the examination of soft tissue and osseous tissues in the head‑and‑neck region. This study compared the accuracy of USG and computed tomography (CT) scan in the diagnosis of mandibular fractures.

    Materials and Methods

    In this prospective observational study, spiral CT scan was prescribed for the lower face and, if necessary, midface and upper face in 42 trauma patients suspected of mandibular fractures, referring to Imam Reza Hospital in Tabriz. Two radiologists evaluated the CT scans. Then, another radiologist examined all the patients with USG with a frequency of 7–12 MHz. Ultrasonographic diagnostic results were recorded and compared with the results of the CT scan examinations. The results were reported using descriptive statistical methods

    Results

    The specificity and sensitivity of USG were 100% and 91.1%, respectively. The USG sensitivities in the angle, condyle, condylar neck, and symphysis fractures were 100%, 91.6%, 85.7%, and 80%, respectively, and the specificity was 100% in all that anatomical regions. Among the confounding factors, the sensitivity of the USG (84.6%) was the lowest in the presence of hematoma; however, its specificity remained 100%. One case of symphysis fracture was not detected in the absence of any confounding factors in USG examination.

    Conclusion

    Although the sensitivity, specificity, and diagnostic accuracy of the USG were at high levels, there were some limitations, making it difficult to definitively replace USG with CT scans, especially in the case of condylar fractures and in the presence of confounding factors such as hematoma and swelling.

    Keywords: Computed tomography scan, mandibular fracture, sensitivity, specificity, ultrasonography
  • Farnoosh Mohammadi, Gholamreza Shirani, Samira Derakhshan, Taraneh Faghihi* Pages 231-234

    Desmoplastic fibroma (DF) is a rare benign but aggressive fibrous lesion with an unknown etiology. It has an affinity for the mandible. DF has a high rate of recurrence after surgical resection. In this study, we report the therapeutic management of a recurrence of DF in the lower jaw in a 2‑year‑old boy. He responded well to second surgical intervention with wide resection and immediate reconstruction with plate. The purpose of this case report is to emphasize the particularity of the case, treatment modalities, and differential diagnosis in DF.

    Keywords: Desmoplastic fibroma, mandibulectomy, pediatric patient