فهرست مطالب

Journal of Dental Materials and Techniques
Volume:3 Issue: 2, Spring 2014

  • تاریخ انتشار: 1393/01/22
  • تعداد عناوین: 8
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  • Massoumeh Zargaran* Pages 47-54
    Biopsy is a useful technique for definitive diagnosis of abnormal oral conditions and it must be performed carefully since any error may result in histopathologic misidentification of the lesion. Present study evaluated the most relevant literatures published between 1982 and 2012 in order to review existed guidelines of correct biopsy performance using scientific database sources such as PubMed, MEDLINE, IMEMR, and Chemical Abstract. The aim of this study was to increase knowledge of dental practitioners especially general dentists about factors which may influence optimization of oral biopsy.
    Keywords: Biopsy, dentistry, histopathology, oral lesion, specimen
  • Iman Parisay, Zahra Bahrololomi, Maryam Ghafournia, Ali, Asghar Solaimani, Alireza Boruziniat* Pages 55-60
    Introduction
    The aim of this study was to evaluate the influence of different light curing systems and curing times on the micro-hardness of a resin modified glass ionomer.
    Methods
    Forty two samples of Resin Modified Glass Ionomer (RMGI) were prepared using stainless steel cylindrical mold (8 × 2 mm) and randomly divided into six groups of seven. Three groups were cured with a Quartz Tungsten Halogen (QTH) light cure unit and the other three groups were polymerized with LED unit for 20, 30 and 40 seconds. All samples were stored in distilled water for 24 hours. The micro-hardness was measured on the top and bottom surfaces of the samples by Vickers hardness tester. Data were analyzed by two–way ANOVA and Tukey’s post-hoc tests.
    Results
    Two-way ANOVA showed that QTH light-cure unit had higher percentage in depth of cure than LED light-curing unit in both surfaces; whereas, the application time has no significant effect on it. There was no interaction between two variables. In both light-curing groups, the values of top and bottom surfaces micro-hardness were increased as the application time increased, but there was not any statistically significant difference among these groups except for 40-second group of LED light-curing unit which was significantly higher than 20-second and 30-second groups (P<0.05). The micro-hardness value of QTH light-curing unit was higher than LED light-curing unit.
    Conclusion
    The application of QTH light-curing unit for at least 20 seconds produces sufficient micro-hardness and depth of cure of RMGI
    Keywords: Glass ionomer, light curing unit, micro, hardness
  • Fahimeh Farzanegan, Behrad Tanbakuchi* Pages 61-65
    Introduction
    One of the clinical problems in orthodontics is the bonding of brackets to composite restorations. The aim of this study was to evaluate the shear bond strength of brackets bonded to composite restorations using Excite.
    Methods
    Forty brackets were bonded to composite surfaces, which were embedded in acrylic resin. One of the following four protocols was employed for surface preparation of the composite: group 1) 37% phosphoric acid for 60 seconds, group 2) roughening with a diamond bur plus 37% phosphoric acid for 60 seconds, group 3) 37% phosphoric acid for 60 seconds and the applying Excite®, group 4) roughening with diamond bur plus 37% phosphoric acid for 60 seconds and applying Excite®. Maxillary central brackets were bonded onto the composite prepared samples with Transbond XT. Shear Bond Strength (SBS) was measured by a universal testing machine. The ANOVA and Tukey test was utilized for data analysis.
    Results
    There was a significant difference between the four groups (P<.000). The lowest and highest SBS were attributed to the Group 1 and Group 4 respectively. There was no significant difference between Groups 1 & 3, 2 & 3 and 2 & 4. However, differences between Group 1 in comparison with Groups 2 and 4 and Group 3 with Group 4 were statistically significant.
    Conclusion
    According to the results of this study, the usage of Excite® alone beforebonding brackets to composite restorations does not cause an increase in bond strength. However, roughening the composite surface before applying Excite is very effective for improving the bond strength of orthodontic brackets to composite restorations
    Keywords: Bond strength, composite restorations, orthodontic brackets
  • Maryam Ehsani, Farida Abesi*, Tania Ghasemi Pages 66-70
    Introduction
    There is substantial evidence that the technical quality of rootcanalfilling has a significant effect on the outcome of root canal treatment. Theaim of this study was to evaluate the technical quality of root canal fillingsperformed by dental students.
    Methods
    The records of 325 teeth radiographs, treated by dental students in 2008-2009 in Babol Dental School, were selected and evaluated. For each tooth, three periapical radiographs (before treatment, during operation and at the end of treatment) were examined. Filling length, density and taper, and presence or absence of void was evaluated. Obturations that have proper length, density and taper, without any void are classified as acceptable root canal fillings. The SPSS statistical software and Chi-Square test were used for analysis.
    Results
    Of the 325 radiographs, 72% had good length and 75% had acceptable taper. There were 14.2% low densities, whereas, only 3.32% of teeth have no void. At least 17.8% of teeth had underfilling and 10.2% overfilling. Finally, only 17.5% of teeth showed acceptable filling length, taper and density without any void. There was no significant difference between the 4th and 5th year students and oral hygienist (who studied oral hygiene and now continuing it to dentistry) in root canal filling quality (P> 0.05).
    Conclusion
    Technical quality of root fillings performed by dental students was found to be less than 20%.. It should be revised in the endodontic curriculum requirement to improve their performance
    Keywords: Dental students, periapical radiographs, quality, root canal treatment
  • Davoud Ghasemi, Sara Rajaei, Ershad Aghasizadeh Pages 71-76
    Introduction
    The purpose of the present study was to record their pain sensation and to assess children`s reaction objectively and subjectively while receiving dental local anesthesia with 27- and 30-gauge needles.
    Methods
    Forty children (24 boys and 16 girls) participated in this study. A random double-blinded crossover design was used so that each child served as his or her own control, receiving each treatment on the same sides of the same arch at different sessions. Each patient received an injection either with a 27- or 30-gauge needle during the second visit and during the third visit with the other needle. Objective and subjective evaluations were performed.
    Results
    Children`s reactions to mandibular nerve block with 27- or 30-gauge needle regarding SEM scale and Face scale demonstrated significant difference, whereas children receiving the injection with a 27-gauge needle presented more sensation of pain objectively and subjectively.
    Conclusion
    Significant difference was demonstrated concerning pain when 27-gauge or 30-gauge needle was used, and no difference was found in success of local anesthesia. As to these two variables, measured and reported in this study, it can be concluded that 30-gauge needle exhibit clinical advantage in inferior dental injection in children.
    Keywords: Face scale, inferior dental nerve block, 30, gauge needle, 27, guage needle, SEM scale
  • Neda Naghavi, Armita Rouhani, Sahar Irani, Nadia Naghavi, Elham Banihashemi* Pages 77-81
    Introduction
    The ultimate goal of endodontic treatment is to eliminate the bacterial infection in the root canal system. While mechanical debridement combined with chemical irrigation removes the bulk of microorganisms, residual bacteria are readily detectable in approximately one-half of teeth just prior to obturation. Laser light can be used to destroy bacteria. This in vitro study was performed to evaluate the effect of diode laser and calcium hydroxide on mono-infected dental canals.
    Methods
    Fifty five single-rooted human premolars were prepared and contaminated with Enterococcus faecalis. After three weeks of incubation, the samples were divided into three experimental groups (n = 15) and two control groups (n = 5). In the first and second groups, the teeth were rinsed for 5 min with either sterile saline or 5.25% NaOCl and irradiated with a 810-nm diode laser at 1.5 W output for 5 × 4s. In the third group, the teeth were rinsed with 5.25% NaOCl and then Ca(OH)2 paste was inserted in the canals for 1 week. Intracanal bacterial sampling was done and the samples were plated to determine the CFU count.
    Results
    5.25% NaOCl plus laser was as effective as calcium hydroxide and significantly more effective than sterile saline (P>0.05) in elimination of E. faecalis. Complete elimination of E. faecalis was seen only for the one week calcium hydroxide treatment.
    Conclusion
    Combination therapy with NaOCl irrigation and diode laser irradiation can be recommended as an effective treatment option for elimination of E. faecalis from the root canal system.
    Keywords: Antibacterial properties, Calcium hydroxide, Diode laser, Enterococcus faecalis
  • Arezoo Jahanbin, Behrad Tanbakuchi* Pages 82-86
    The aim of this case report was to introduce an appliance for correcting severe rotation of anterior teeth in the mixed dentition period. A 9-year-old Iranian boy with a mixed dentition Class I malocclusion complained of a severely rotated of upper right central incisor. There was a mesiodens between the central incisors. The supernumerary tooth was first extracted and then a Whip appliance which is composed of a removable plate, a cantilever spring and a central bracket on the rotated tooth was utilized. After 8 months, the upper right central incisor was orthodontically brought into proper alignment. Circumferential supracrestal fibrotomy was performed on the overcorrected tooth. One week after surgery, the device was removed and the retention was started. The whip appliance is a removable appliance that can effectively correct severe rotation of anterior teeth especially during the mixed dentition period.
    Keywords: Orthodontics, rotation, whip appliance
  • Siavash Moushekhian, Masoud Shiehzadeh, Amir Shammas Pages 87-90
    The anatomic anomalies detection is important for an attentive clinician. A successful treatment of an endodontically involved tooth should make it functional and aesthetically acceptable for the patient. The following article presented a case of gemination and the endodontic, prosthetic and periodontal treatments which were done to keep a complicated tooth in aesthetic zone
    Keywords: Clinical management, germination, maxillary lateral incisor