فهرست مطالب

Journal of Dental Research, Dental Clinics, Dental Prospects
Volume:6 Issue: 3, Summer 2012

  • تاریخ انتشار: 1391/07/18
  • تعداد عناوین: 8
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  • Mehrdad Lotfi, Negar Moghaddam, Sepideh Vosoughhosseini, Vahid Zand, Mohammad Ali Saghiri Page 79
    Background And Aims
    The aim of the present study was to compare 1.3% sodium hypochlorite (NaOCl) in MTAD (mixture of tetracycline isomer, acid, and detergent) for the removal of the smear layer and induction of canal erosion.
    Materials And Methods
    38 maxillary incisors were divided in three experimental groups of 10 and two positive and negative control groups of each 4 teeth, and prepared using rotary files. In test groups, 1.3% NaOCl was used for 5, 10 and 20 minutes during preparation followed by MTAD as the final rinse. In negative control group, 5.25% NaOCl was used for 10 minutes followed by 17% Ethylenediamine Tetra-Acetic Acid (EDTA) as the final rinse. In positive control group, dis-tilled water was used for 10 minutes during preparation and then as the final rinse. The samples were examined under scan-ning electron microscope, and the smear layer and dentinal erosion scores were recorded.
    Results
    Five and 10 min groups had significant differences with 20 min group (p < 0.05). In apical third, 5 and 10 min groups had also significant differences with 20 min (p < 0.05). In the coronal thirds, when the time of irrigation with 1.3% NaOCl increased from 5 min to 20 min, erosion also increased significantly. However, 5 and 10 min groups had no signifi-cant differences with negative control group.
    Conclusion
    The use of 1.3% sodium hypochlorite for 5 and 10 minutes in the MTAD protocol removes the smear layer in the coronal and middle thirds but does not induce erosion.
  • Maryam Kuzekanani, Jahangir Haghani, Hossein Nosrati Page 85
    Background And Aims
    A through knowledge of the root canal morphology is required for successful endodontic therapy. The aim of this study was to investigate the root and canal morphology of mandibular third molars in Kerman, a province in southeast of Iran.
    Materials And Methods
    One-hundred-fifty extracted mandibular third molars were collected randomly from different dental clinics in Kerman. The root canal anatomy and morphology of each tooth was carefully studied using a clearing technique. Root number and morphology, number of canals per root, root canal configuration according to Vertucci classification, and incidence of dilacerated roots and C-shaped canals in mandibular third molars were evaluated under stereomicroscope with ×2 to ×3 magnifications.
    Results
    From the total of 150 mandibular third molars studied, 21% had one root. The majority of teeth (73%) had two roots. 5.5% of the teeth had three roots. The incidence of C-shaped canal was 3.5% in this study and 8% of the teeth had at least one dilacerated root.
    Conclusion
    Although root canal anatomy and morphology of mandibular third molars is very variable having two roots seems to be the normal anatomy for these teeth.
  • Mehdi Kashani, Sareh Farhadi, Neda Rastegarfard Page 89
    Background And Aims
    This in vitro study was designed to compare enamel demineralization depths adjacent to bands cemented with zinc polycarboxylate, glass ionomer (GI) and resin-modified glass ionomer (RMGI), in order to achieve minimal enamel demineralization during orthodontic treatment.
    Materials And Methods
    Sixty fully developed extracted third molars were randomly divided into three test groups each containing 20 samples, used to cement orthodontic bands with zinc polycarboxylate, GI and RMGI. All samples were demineralized using White method using hydroxyapatite, latic acid and Carbapol for in vitro caries simulation, and then, immersed in 10% solution of methylene blue. The mean depth of dye penetration was assessed up to 0.1 millimeter, reflecting the depth of enamel demineralization. One way ANOVA and LSD statistical tests were employed to evaluate significant differences among groups.
    Results
    The highest dye penetration depth was seen in zinc polycarboxylate group, followed by GI, and RMGI groups, respectively, with significant differences among each two groups (P < 0.05).
    Conclusion
    The use of RMGI cement seems to present significantly better prevention of enamel demineralization adjacent to orthodontics bands.
  • Hamid Reza Poureslami, Fatemeh Sajadi, Maryam Sharifi, Shahram Farzin Ebrahimi Page 94
    Background And Aims
    Despite the increasing demand for adhesive restorations in pediatric dentistry, polymerization shrinkage and subsequent marginal microleakage remains a problem. The aim of this study was to evaluate of the sealing ability of novel low-shrinkage composite silorane in class V cavity of primary canines in comparison with three types of composite resin.
    Materials And Methods
    Ninety-one non-carious extracted primary canines were randomly divided in six groups (n=15). Standard class V cavities were prepared on the buccal surface of each tooth that the occlusal margin was in the enamel and the cervical margin extending 1 mm below the cemento-enamel junction. The preparations were restored with the different composite materials in normal consistency with application the bonding in six groups (Filtek silorane; etch + Filtek Silorane; Z250; Filtek supreme; els saremco; Aelite LS). Teeth were then exposed to thermal cycles (1000 cycles, 5°C and 55°C), sealed and immersed in a 0.5% basic fuchsine for 24 hours, and finally sectioned. Buccolingual and marginal leakage was assessed with dye penetration.
    Results
    The best seal were obtained with etch + Filtek Silorane (P < 0.05) and the weakest seal with Z250 composite restorations (P > 0.05). Except for etch + silorane, there was no significant differences in sealing ability (P > 0.05), and in the microleakage degree at the cementum and enamel margins (P > 0.05) between the groups.
    Conclusion
    According to the results, low-shrinkage silorane composite restorations with etching the cavity provide the highest seal in primary teeth.
  • Fariba Saleh Saber, Nader Abolfazli, Sara Nuroloyuni, Sohleh Khodabakhsh, Mehran Bahrami, Reza Nahidi, Somaieh Zeighami Page 98
    Background And Aims
    In contrast to prepared natural dentin abutments, little is known concerning factors influencing the retention of fixed prostheses cemented to implant abutments. The aim of this study was to investigate the effect of implant abutment height on the retention of single castings cemented to wide and narrow platform implant abutments.
    Materials And Methods
    Thirty-six parallel-sided abutments (Biohorizon Straight Abutment) of narrow platform (NP) and wide platform (WP) sizes with their analogs were used. In each group of platform size, abutments were prepared with axial wall heights of 5, 4, 3, 2 mm (n=9). On the whole 72 castings were constructed, which incorporated an attachment to allow removal. Castings were cemented to abutments with TempBond®. A uniaxial tensile force was applied to the crown using an Instron machine until cement failure occurred. Analysis of variance of the models were fit to determine the effect of height of abutment of the restorations on the mean tensile strength (α=0.05).
    Results
    The mean peak removal force for corresponding abutments was significantly different (P < 0.05): (1) with platform sizes: WP > NP; (2) with alteration of axial wall height for NP: 5 mm > 4 mm > 3 mm = 2 mm and for WP: 5 mm > 4 mm = 3 mm = 2 mm.
    Conclusion
    The retention of NP cement-retained restorations is influenced by the wall height but not in same manner as WP. Restorations of narrow-platform size with longer abutment exhibited higher tensile resistance to dislodgement.
  • Noushin Jalayer Naderi, Farrokh Tirgari, Farzin Esmaili, Faranak Paktinat, Zahra Keshavarz Page 103
    Background And Aims
    Vascular endothelial growth factor (VEGF) and Ki-67 antigen are contributing factors in this process cell proliferation and new blood vessels formation in tumor progression. This study was conducted to examine the relationship between the expression of VEGF and Ki-67 and gender and age of patients with oral squamous cell carcinoma (OSCC).
    Materials And Methods
    Twenty-three archival samples of well-differentiated OSCC were examined immunohistochemically and assessed by obtaining Total Score (TS = proportion score × staining index). For statistical analysis, t-test and Pearson’s correlation were employed. P≤0.05 was considered statistically significant.
    Results
    The differences in VEGF expression between males and females (P = 0.43) and different ages (P = 0.88) were not significant. The differences in Ki-67 expression was between males and females (P = 0.67) and different ages (P = 0.88) were also not significant. A positive correlation of VEGF and Ki-67 expression was observed in males and females in addition to ≤ 60 years age group (r = 0.22, r = 0.008, and r = 0.58, respectively; P < 0.05). The expression of VEGF had a negative relation to Ki-67 in > 60 years group (r = −0.48, P < 0.05).
    Conclusion
    The expression of VEGF and Ki-67 between males and females and different ages were not significant among oral squamous cell carcinoma cases evaluated.
  • Somayeh Hekmatfar, Karim Jafari, Raziyeh Meshki, Samaneh Badakhsh Page 108
    Ectodermal dysplasia is a hereditary disorder associated with abnormal development of embryonic ectodermally-derived organs including teeth, nails, hair and sweat glands. Hypodontia of the primary and permanent dentition is the most common oral finding. Therefore, affected patients need dental prosthetic treatments during their developmental years. This report presents two cases of children affected by ectodermal dysplasia with anodontia. Oral rehabilitation was accomplished with removable acrylic prostheses. Treatment had major impacts on self-esteem, masticatory function, speech and facial esthetic.
  • Ali Hossein Mesgarzadeh, Mohammad Ali Ghavimi, GulŞ, En Gok, Afsaneh Zarghami Page 113
    Infratemporal space infection is a rare but serious sequel of odontogenic infection. The diagnosis is difficult due to non specific signs and symptoms. Diabetes mellitus as a definitive risk factor for odontogenic infections needs more consideration during clinical procedures. We report a case of an undiagnosed diabetic patient with isolated infratemporal space infection after tooth extraction with presentation of similar signs and symptoms of temporomandibular joint and muscle problem.