فهرست مطالب

Journal of Dental Research, Dental Clinics, Dental Prospects
Volume:5 Issue: 2, Spring 2011

  • تاریخ انتشار: 1390/08/17
  • تعداد عناوین: 8
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  • Ezatollah Jalalian, Roghayeh Rostami, Berivan Atashkar Page 41
    Background and aims. One of the major problems of all-ceramic restorations is their probable fracture under occlusal force. The aim of the present in vitro study was to compare the effect of two marginal designs (chamfer and deep chamfer) on the fracture resistance of all-ceramic restorations, CERCON.Materials and methods. This in vitro study was carried out with single-blind experimental technique. One stainless steel die with 50’ chamfer finish line design (0.8 mm deep) was prepared using a milling machine. Ten epoxy resin dies were prepared. The same die was retrieved and 50' chamfer was converted into a deep chamfer design (1 mm). Again ten epoxy resin dies were prepared from the deep chamfer die. Zirconia cores with 0.4 mm thickness and 35 µm cement space were fabricated on the epoxy resin dies (10 chamfer and 10 deep chamfer samples). The zirconia cores were cemented on the epoxy resin dies and underwent a fracture test with a universal testing machine and the samples were investigated from the point of view of the origin of the failure.Results. The mean values of fracture resistance for deep chamfer and chamfer samples were 1426.10±182.60 and 991.75±112.00 N, respectively. Student’s t-test revealed statistically significant differences between the groups. Conclusion. The results indicated a relationship between the marginal design of zirconia cores and their fracture resistance. A deep chamfer margin improved the biomechanical performance of posterior single zirconia crown restorations, which might be attributed to greater thickness and rounded internal angles in deep chamfer margins.
  • Katayoun Sadr, Farhang Mahboub, Elaheh Rikhtegar Page 46
    Background and aims. The first few days following the insertion of complete dentures are critical for the patients since they are struggling to adapt to their new dentures. This study aimed to evaluate the most common locations of traumatic ulcerations, their frequency and also the duration and number of adjustment visits required to achieve patient comfort following placement of complete dentures.Materials and methods. Sixty patients were selected from edentulous patients referring to a removable prosthodontics department. Complete dentures were fabricated for the patients. After placement of dentures, all the patients were evaluated from the day after placement until patient comfort was achieved. Descriptive analysis was performed and chi-squared test was used to evaluate the associations between lesions, post-insertion visits and gender.Results. A total of 85.8% of patients required denture adjustment because of mucosal injuries during their first visit following denture placement. Maxillary and mandibular dentures did not require further adjustments after fourth and sixth visits, respectively. No significant differences were detected between males and females in the number of mucosal injuries in the anatomical areas evaluated in the maxilla and mandible using Fisher's exact test (P > 0.05). Furthermore, the number of mandibular dentures requiring adjustments was significantly higher than maxillary dentures in all the post-insertion appointments (P < 0.001). Conclusion. Since most mucosal injuries are located in the vestibule, adequate extension of denture flanges, especially during border molding, and use of pressure indicators that reveal over-extended borders, play an important role in decreasing mucosal injuries and improving patient comfort following complete denture placement.
  • Rishabh Kapila, K.S. Nagesh, Asha R. Iyengar, Sushma Mehkri Page 51
    Background and aims. The aim of this study was to determine whether variations in the mesiodistal dimensions of mandibular canines had any role in sex determination.Materials and methods. The study comprised of patients in the 19‒24-year age group (20 males and 20 females). Mesiodistal dimensions of mandibular canines was measured at the maximum mesiodistal width, first intraorally, then on plaster models of the same patient, followed by intraoral periapical radiograph of the same patient. The values were subjected to statistical analysis using t-test.Results. It might be concluded from the results that there exists a definite statistically significant difference in the mesiodistal width of mandibular canines when measured for males and females. Moreover, the left mandibular canine showed a greater sexual dimorphism (9.7%) when compared to the right mandibular canine (7.4%). Conclusion. The present study establishes a statistically significant sexual dimorphism in mandibular canines. It can be concluded that the standard mandibular canine index is a quick and easy method for determining sex and in identification of an unknown individual.
  • Nikolaos Chrysanthakopoulos Page 55
    Background and aims. The aim of this study was to investigate the prevalence of permanent teeth extracted due to periodontal disease and its relation to age, military rank, and type of extracted teeth due to periodontal and non-periodontal reasons among a group of Greek Army personnel attending a military dental practice.Materials and methods. Study population consisted of 509 officers, non-commissioned officers and soldiers, aged 18 to 44 years from a military dental hospital in Greece. The reasons for extractions of teeth for a period of two years were obtained, including aspects such as age, military rank and the type of teeth extracted due to periodontal and non-periodontal reasons. Data were analyzed using chi-squared test.Results. The total number of extracted teeth was 1,231, of which 34.4% were extracted because of periodontal reasons, 32.2% for dental caries and 33.4% for other reasons. The average number of extracted teeth due to periodontal disease showed an increase with age. Maxillary and mandibular first and second molars were the most frequently extracted teeth due to periodontal reasons; however, the anterior teeth of both jaws with mobility (grade III), the same teeth with attachment loss (≥5.0 mm) and the posterior teeth of both jaws with furcation involvement (grade IV) were the most frequently extracted teeth due to periodontal reasons.Conclusion. Although the goal of the WHO regarding the reduction of dental caries was accomplished, periodontal disease was still the main cause of tooth extraction and showed an increase with age.
  • Adriane Kamulegeya, William Buwenbo, Charles Mugisha Rwenyonyi Page 61
    Background and aims. Irrational prescription of antibiotics by clinicians might lead to drug resistance. Clinicians do prescribe antibiotics for either prophylactic or therapeutic reasons. The decision of when and what to prescribe leaves room for misuse and therefore it is imperative to continuously monitor knowledge and pattern of prescription. The aim of the present study was to determine the knowledge of antibiotic use and the prescription pattern among dental health care practitioners in Uganda. Materials and methods. A structured and pretested questionnaire was sent to 350 dental health care practitioners by post or physical delivery. All the questionnaires were sent with self-addressed and prepaid postage envelopes to enable respondents to mail back the filled questionnaires. Chi-squared test was used to test for any significant differences between groups of respondents based on qualitative variables.Results. The response rate was 40.3% (n=140). Of these 52.9 % were public health dental officers (PHDOs) and 47.1% were dental surgeons. The males constituted 74.3% of the respondents. There were statistically significant differences between dental surgeons and (PHDOs) in knowledge on prophylactic antibiotic use (P = 0.001) and patient influence on prescription (P = 0.001). Amoxicillin, in combination with metronidazole, was the most common combination of antibiotics used followed by co-trimoxazole with metronidazole. Conclusion. The knowledge of dental health care practitioners in antibiotic use in this study was generally low. A combination of amoxicillin with metronidazole was the most commonly prescribed antibiotics subsequent to different dental procedures.
  • Tahmineh Razi, Seyyed Hossein Moslemzadeh, Morteza Ghojazadeh, Leila Bazvand Page 67
    Background and aims. Pregnant women often do not receive proper dental care in emergency visits due to a lack of awareness of the effect of radiation doses and the involved risks for the fetus. The aim of the present study was to assess the awareness of general dentists practicing in Tabriz, Iran, of the risks involved during exposure to diagnostic dental radiation in pregnant women.Materials and methods. In this descriptive/cross-sectional study, 250 general dentists, who had attended continuing education courses under the supervision of the Faculty of Dentistry, filled out questionnaires on their awareness of radiation risks. Data was analyzed by Spearman's correlation coefficient test.Results. The mean of correct answers was 6.47±1.66, with the least and highest correct answers of 2 and 10, respectively. The highest and the lowest levels of awareness were related to the use of a lead apron (92%) and a long rectangular collimator (3.2%), respectively. There was a statistically significant correlation between the age of practitioners and awareness of radiation risks (P=0.02). However, no statistically significant correlation was observed between job experience (P=0.25) and the number of continuing education courses attended (P=0.16) and awareness of radiation risks. Conclusion. The studied population of dentists does not seem to have the sufficient knowledge regarding the diagnostic dental radiation risk during pregnancy. Further educational courses and pamphlets are recommended for increasing their awareness of this subject.
  • Farhang Mahboub, Katayoun Sadr, Fateme Heidary, Elham Hosseini Page 71
    An abnormally small oral orifice is defined as microstomia. Microstomia may result from epidermolysis bullosa (EB), which consists of a group of disorders characterized by the presence of mechanical fragility of the skin with recurrent development of blisters and vesicles, resulting from minor mechanical friction or trauma. Since such patients have a small oral aperture, it may be impossible to take impression and fabricate dentures using conventional methods. In this article, a simple method for taking preliminary impressions from upper and lower edentulous ridges in one patient with limited mouth opening and then preparing the complete denture with custom denture teeth in a single unit was described.
  • Sepideh Vosough Hosseini, Monir Moradzadeh, Mehrdad Lotfi, Amir Ala Aghbali, Shirin Fattahi Page 76
    Dentigerous cysts are the second most common odontogenic cysts after radicular cysts and are most commonly seen in association with third molars and maxillary canines. Only 5% of dentigerous cysts involve supernumerary teeth, of which mesiodens is the most frequent type. This paper presents a case of dentigerous cyst associated with a mesiodens that caused a painless swelling in the upper lip of an 18-year-old female. The patient was treated surgically by enucleation of total cyst and surgical extraction of mesiodens under local anesthesia