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Dentistry, Shiraz University of Medical Sciences - Volume:18 Issue: 4, Dec 2017

Journal of Dentistry, Shiraz University of Medical Sciences
Volume:18 Issue: 4, Dec 2017

  • تاریخ انتشار: 1396/09/11
  • تعداد عناوین: 12
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  • Tahereh Nosratzehi * Pages 237-243
    Squamous cell carcinoma of oral cavity is of malignant tumors, which causes cancerous complications. DNA damage, mainly because of products of oxidative stress like reactive oxygen species, is a frequent mutagenic that triggers carcinoma. Smoking increases the probability of cancer incidence. Saliva is the first biological medium to interact with external compounds, especially smoking substances. The present study overviews the salivary level of some remarkable compounds in relation with smoking and squamous cell carcinoma.
    To collect data, English literature was searched in databases including PubMed, ScienceDirect and Google Scholar. The keywords used for search were as follows: ‘Carcinoma, Squamous Cell’, ‘Smoking’, ‘Saliva’, and ‘Biomarkers‘. The inclusion criteria were the presence of salivary chemical factors in relation with oral cancer and influence by smoking. Out of 239 found articles, only 56 were selected.
    Our results demonstrated the potential role of salivary biochemistry to predict and/or treat complications with cancer in both smoker and non-smoker individuals.
    Changes in concentrations of salivary chemicals including antioxidants, total antioxidant, glutathione and uric acid, epithelial growth factor, cytokine biomarkers, superoxide dismutase activity, and transcriptome were related to squamous cell carcinoma and could be used as potential biomarkers for cancer prognosis; moreover, enhancement of antioxidant level might be a potential treatment.
    Keywords: Carcinoma, Squamous Cell, Smoking, Saliva, Biomarkers
  • Leila Khojastepour, Abdolaziz Haghnegahdar, Marzieh Keshtkar * Pages 244-250
    Statement of the Problem: The surgical procedure of dental implantation in anterior maxillary area may be limited by the shape and size of nasopalatine canal (NPC). CBCT imaging provides three–dimensional information for surgical planning.
    Purpose
    This study is designed to evaluate the anatomy of NPC in a selected Iranian population.
    Materials And Method
    In this cross sectional study, CBCT images of 301 patients were evaluated for NPC characteristics. Five linear measurements including width and length of NPC were performed on reformatted sagittal cross sections. The shapes of NPC were also classified in three groups according to Bronstein et al. classification in CBCT coronal cross sections. The effects of age and gender on measured dimension were assessed. Student’s t-test, one-way ANOVA/Tukey HSD tests, chi-square and Pearson’s correlation coefficient were used for statistical analysis.
    Results
    The study comprised 140 males (48.5%) and 161 females (53.5%) with mean age of 34.56±11.87. The mean length of NPC for men and women were 11.46 and 9.37 mm respectively, showing a significant statistical difference. Other dimensions of NPC and alveolar bone thickness were also greater in men with exception of buccal bone plate width in front of Stensen foramen (8.45±2.24 vs. 8.52±2.03 mm).Most of the cases showed Y-shape configuration. The diameter of oral opening of NPC (3.17±1.01 mm) was positively correlated with the patients age (r= 0.138, p= 0.01), while buccal bone over the oral opening of NPC (7.05±1.38) mm showed negative correlation with age (r= -0.199, p= 0.001).
    Conclusion
    All NPC dimensions are meaningfully greater in men except for buccal bone plate thickness in front of Stensen foramen. The type of canal has no effect on dimensions of the canal.
    Keywords: Nasopalatine Canal, Cone Beam Computed Tomography (CBCT), Anatomic Variation
  • Abdolhamid Zafarmand *, Maryam Asvar Pages 251-258
    Statement of the Problem: Lifestyle has a key role in having a life with quality. This is much more critical in academic community. Elite students are the scientific capital of each community; therefore, improvement of their life-style is a very crucial issue and is a way of esteeming them.
    Purpose
    This study was aimed to scrutinize the life-style of elite dental students to provide a guideline for healthy life-style for their own and for other students, as well.
    Materials And Method
    This descriptive and cross-sectional study was carried out on 115 Elite dental students, from a list 175 students, based upon their interest. The HPLP-II questionnaire was used which focuses on 6 behavioral fields: Spiritual Growth, Interpersonal Relations, Nutrition, Physical Activity, Health Responsibility, and Stress Management. The results also compared genders and marital status within the study group. The elite dental students were categorized in 3 age groups as 19≥ yrs (Group I), 20-22 yrs (Group II), and 23≤ yrs. (Group III) for comparison. Data were analyzed using SPSS version 19, independent t-test, one-way ANOVA, and Tukey’s test.
    Results
    The mean score of the HPLP-II questionnaire was 2.51±0.27 (out of score 4). Spiritual growth (2.85±0.42) and physical activity (2.16±0.58) were the highest and the lowest scores, respectively. Physical activity was the only subscale different between genders (p= 0.000). Marital status had not effect on life-style of students. Between the age groups, the physical activity was significantly different between group I and II (0.002).
    Conclusion
    Elite dental students’ life-style is most prominent in spiritual growth and interpersonal relationships dimensions, but is the weakest in physical activity and health responsibility behavioral attitudes. To improve the talent of all students, interventional workshops/courses aiming at modification and promotion of student's lifestyle is recommendable in the curriculum.
    Keywords: Life Style, Dental Student, Spirituality, Oral Health, Interpersonal Relations, Nutrition, Physical Activity, Health, Stress, Health Promotions
  • Zohre Jaafari-Ashkavandi *, Behrooz Akbari Pages 259-264
    Statement of the Problem: It is necessary for surgeons and practitioners to know about relative incidence and clinicopathologic features of lesions for accurate diagnosis and approach of pathologic lesions. Data are limited about overall incidence of intra-osseous lesions of the jaws in Iranian patients.
    Purpose
    This study evaluated the clinicopathologic features of intra- osseous lesions of the jaws in an Iranian population, in a 22-year period.
    Materials And Method
    In this cross- sectional retrospective analytical study, 4500 specimens in a 22- year period were reviewed. Baseline data of all patients with intra- osseous lesions including type and location of lesions as well as patients’ age and gender, were collected and analyzed by SPSS software using descriptive analysis and Chi-square test.
    Results
    There were 1121 (25%) intra-osseous lesion. Odontogenic cysts and benign non- odontogenic bone lesions were the most common categories, respectively. The mean age of the patients was 30.1±16, the total male to female ratio was 1.1:1, and the most prevalent location of lesions was posterior of mandible.
    Conclusion
    The results showed baseline information of intra-osseous lesions that were essentially similar to other populations; however, there were a few geographical differences. Further comprehensive studies in other parts of country are required to make a more reliable source of reference for clinicians and surgeons for evaluating and managing their patients more properly.
    Keywords: Bone lesions, Prevalence, Jaws, Odontogenic cysts, Odontogenic tumors
  • Yasmin Sheikh Hasani, Mehrsa Paryab*, Aida Saffarpour, Mohammad Javad Kharazifard, Mehdi Shahrabi Pages 265-271
    Statement of the Problem: There are some concerns regarding the effect of chlorhexidine (CHX) applied for cavity disinfection on the bond strength of adhesive restorations to dentin.
    Purpose
    This study sought to assess the effect of CHX on the shear bond strength (SBS) of Equia resin-modified glass ionomer cement (RMGIC) to dentin in permanent teeth.
    Materials And Method
    In this experimental study, the buccal surface of 84 freshly extracted human premolars was ground to expose the flat dentin. The samples were randomly assigned to four groups (n=21). The steps were as following in the group Ia: conditioning, Equia RMGIC, 500 thermal cycles; group Ib: conditioning, Equia RMGIC, 6000 thermal cycles; group IIa: conditioning, CHX, Equia RMGIC, 500 thermal cycles, and group IIb: conditioning, CHX, Equia RMGIC, and 6000 thermal cycles. Twenty samples from each group were subjected to SBS test and one sample was inspected under a scanning electron microscope. Data were analyzed using two-way ANOVA and t-test.
    Results
    The SBS was significantly different among the groups (p= 0.007). The groups subjected to 500 thermal cycles showed significantly higher SBS to dentin when they were treated with CHX (p= 0.000). There was no significant difference between samples thermocycled for 6000 cycles with and without application of CHX (p= 0.269). The SBS in the groups that were thermocycled for 6000 cycles (Ib and IIb) was lower than those thermocycled for 500 cycles (Ia and IIa). This difference between IIa and IIb was statistically significant (p= 0.007).
    Conclusion
    Chlorhexidine can positively affect the short term SBS of Equia RMGIC to dentin.
    Keywords: Chlorhexidine, Dental Cavity Preparation, Disinfection, Dentition, Permanent, Glass Ionomer Cement, Shear Strength
  • Rasoul Gheisari *, Hesamuddin Eatemadi, Akram Alavian Pages 272-276
    Statement of the Problem: Dental implant is one of the best choices for reconstruction of aesthetic and function. High success rate of these treatments are related to some considerations such as case selection, implant system selection and surgical methods. One-stage or two-stage surgical approaches are routine surgical methods in dental implant treatments. The minimum rate of bone loss around fixtures is the most important criteria for evaluation of implant treatment success that can be affected by different methods of surgery.
    Purpose
    This experimental study has been done to compare the crestal bone loss at mesial and distal surface of implants installed through either one-stage or two-stage surgical approach.
    Materials And Method
    In the present randomized clinical trial, 310 Astra Tech implant system were divided into two unequal groups to be used for 140 patients. One hundred and seventy implants were inserted through one-stage and 140 through two-stage surgical approach. The baseline parallel periapical radiography was provided immediately after the surgery. Six months after the functional loading, another radiographic image was provided by using the same technique and machine. Marginal bone loss was calculated by using Adobe Photoshop CS5 software. Data were statistically analyzed with SPSS software. P values less than 0.05 were considered as significant.
    Results
    The mean Bone loss on the mesial and distal surfaces of implants inserted through one-stage surgery and two-stage surgery was 0.76±0.04 and 0.842±0.04 mm respectively. No notable marginal bone change was observed between the maxilla (0.860mm) and mandible (0.729mm). Moreover, p Value was>0.05 in all samples, indicating no significant difference in the crestal bone loss.
    Conclusion
    Accordingly, one-stage surgical technique may provide better esthetic and function for dental implants. There is no significant difference between the two approaches concerning the marginal bone loss.
    Keywords: Dental Implant, Marginal Bone Loss, Periapical Radiography
  • Masoud Khabiri, Maziar Ebrahimi *, Mohammad Reza Saei Pages 277-281
    Statement of the Problem: File fracture can interfere with cleaning and shaping of the canal and compromise periradicular healing. Autoclave sterilization may prone the files to fracture.
    Purpose
    The purpose of the present study was to determine the effect of autoclave sterilization on the cyclic fatigue resistance of Hero642 rotary instrument in two curvatures of 45 and 60 degrees.
    Materials And Method
    For this experimental in-vitro study, 90 Nickel-Titanium HERO 642 rotary files #30 with 0.06 taper were selected. They were divided into two groups (curvature of 45 and 60 degree) of 45 files. Each group was then subdivided into 3 subgroups; group I: no sterilization, group II: 5 cycles of sterilization and group III: 10 cycles of sterilization. Files were used in artificial canals until fracture. The cyclic fatigue was measured as the number of cycles before fracture. The data was statically analyzed by Student’s t-test and two-way analysis of variance.
    Results
    There was a significant difference in cyclic fatigue of two curvature of 45 and 60 degrees (p= 0.001). However, sterilization process has no significant effect on cyclic fatigue of HERO files (p= 0.557).
    Conclusion
    Sterilization had no effect on the cyclic fatigue of HERO 642 files when used in curvature of 45 or 60 degrees.
    Keywords: Cyclic Fatigue, Hero Rotary Instrument, Sterilization
  • Fatemeh Jahanimoghadam, Mahsa Kalantari, Azadeh Horri *, Habibeh Ahmadipour, Ehsan Pourmorteza Pages 282-288
    Statement of the Problem: Since almost half of the child abuse cases affect the head and neck region, dentists have an important role in the diagnosis and report of oral and dental aspects of child abuse cases.
    Purpose
    The objective of the current study was to evaluate the knowledge, attitude and practice of the general dentists and pedodontists regarding child abuse and child neglect.
    Materials And Method
    This cross-sectional study was carried out on the participants of the 12th congress of pedodontists of Iran. A self-administered questionnaire was used for evaluating their knowledge, attitude and practice toward child abuse. T-test and ANOVA were applied to analyze the data by SPSS software. p
    Results
    The mean score of knowledge, attitude and practice of the participants regarding child abuse was 10.24±2.68, 41.54±11.24 and 2.78±1.05, respectively. The knowledge of pedodontists was significantly higher than knowledge of general dentists. No statistically significant difference was observed in attitude and practice (p> 0.05).
    Conclusion
    Dentists had a moderate knowledge, poor attitude and moderate practice regarding child abuse. Considering this fact, improvements in child abuse education for undergraduate students and continuing post-graduate training in this field are recommended.
    Keywords: Attitude, Child Abuse, Dentists, Knowledge, Practice, Iran
  • Abolfazl Saboury, Hamid Neshandar Asli *, Zahra Dalili Kajan Pages 289-297
    Statement of the Problem: Precision of the impression taken from implant positions significantly determines accurate fit of implant-supported prostheses. An imprecise impression may produce prosthesis misfit.
    Purpose
    This study aimed to evaluate the accuracy of four impression-making techniques for angulated implants by stereomicroscope through measuring the vertical marginal gaps between the cemented metal framework and the implant analog.
    Materials And Method
    A definitive cast with two 15° mesially angulated implants served as the standard reference for making all the impressions and later for accuracy evaluation. Four groups of five samples were evaluated: (1) closed-tray snap-fit transfer, (2) open-tray nonsplinted impression coping, (3) metal splinted impression coping, and (4) fabricated acrylic resin transfer cap. A gold-palladium framework was fabricated over the angulated implant abutments, the fit of which was used as reference. The gaps between the metal framework and the implant analogs were measured in sample groups. Corresponding means for each technique and the definitive cast were compared by using ANOVA and post hoc tests.
    Results
    The mean marginal gap was 38.16±0µm in definitive cast, 89±19.74µm in group 1, 78.66±20.63µm in group 2, 54.16±24.29µm in group 3, and 55.83± 18.30µm in group 4. ANOVA revealed significant differences between the definitive cast and groups 1 and 2, but not with groups 3 and 4 (p
    Conclusion
    Vertical gap measurements showed that metal splinted impression coping and fabricated acrylic resin transfer cap techniques produced quite more accurate impressions than closed-tray snap-fit transfer and open-tray nonsplinted impression coping techniques do. The fabricated acrylic resin transfer cap technique seems to be a reliable impression-making method.
    Keywords: Dental Implants, Impression techniques, Dental, Dental Implants, Dental Abutments, Dental Prosthesis
  • Hassan Mohajerani, Roozbeh Roozbayani, Shahram Taherian, Reza Tabrizi Pages 298-303
    Statement of the Problem: Despite the low failure rate of dental implants, recognition of the risk factors can enhance the predictability of failure.
    Purpose
    The aim of this study was to evaluate the risk factors for early implant failure.
    Materials And Method
    This retrospective cohort study was conducted on two groups of patients, the patients with a failed implant before loading and those without a failed implant. Age, gender, implant type, implant surface, implant length, bone type, type of surgery (one- or two-stage) and immediate (fresh socket) or delayed placement of implant were the variables to be assessed in this study.
    Results
    Out of the 1,093 evaluated implants, 73 cases (6.68%) failed in early stages. The two groups were significantly different in terms of implant surface, fresh socket placement, prophylactic use of antibiotics, and bone density (p 0.05).
    Conclusion
    It seems that prophylactic antibiotic therapy, implant surface, bone density and placement in fresh extraction socket may contribute to dental implant failure.
    Keywords: Dental Implants, Risk Factor, Osseointegration, Dental Implantation
  • Nicholas Egbert, Swati Ahuja*, Audrey Selecman, Russell Wicks Pages 304-313
    Until recently, angled abutments have been the only solution to correcting the trajectory of the emergence profile of labially inclined implants in the maxilla. However, the clinical implications of angled abutments reveal several shortcomings. Newly designed angulated implants with a 12-degree restorative platform angulation are an alternative to angled abutments. The purpose of this article was to report a case utilizing new angulated implants (Co-axis, Keystone dental, Burlington, MA, USA) in the premaxilla thereby facilitating fabrication of a multi-unit implant retained fixed dental prosthesis.
    Keywords: Angulated Abutments, Angulated Implants, Co-axis, Labially Inclined
  • Saede Atarbashi-Mohgadam, Ali Lotfi, Saman Salehi Zalani, Sepideh Mokhtari * Pages 314-317
    The rarity of oral soft tissue spindle cell tumors combined with overlapping microscopic patterns can make challenges in their diagnosis and treatment. Oral cavity palisaded encapsulated neuroma is an uncommon lesion which occurs often on the hard palate. It is essential for oral pathologists to be familiar with its histopathology of this lesion is essential since many lesions are probably diagnosed microscopically as neurofibroma or schwannoma. Here, we report a case of oral palisaded encapsulated (solitary circumscribed) neuroma in an unusual site.
    Keywords: Neuroma, Soft Tissue Neoplasms Mouth, Mucosa