فهرست مطالب

Journal of Islamic Dental Association of IRAN
Volume:28 Issue: 3, Summer 2016

  • تاریخ انتشار: 1395/06/19
  • تعداد عناوین: 5
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  • Mohammad Amin Mackie, Shahla Momeni Danaei, Salma Habibagahi, Nader Tanide, Ali Dehghani Najvani, Mostafa Montazeri Pages 86-91
    Background And Aim
    Estrogen affects the metabolism in females. This study aimed to assess the effect of absence of estrogen on orthodontic tooth movement in rats.
    Materials And Methods
    In this animal study, 55 rats were randomly divided into four groups. Group 1 (n=10) had intact ovaries. In group 2 (n=15), ovaries were intact but the rats were subjected to stress due to tooth preparation. In group 3 (n=15), the ovaries were intact but the rats were subjected to stress due to tooth preparation and surgical manipulation. In group 4 (n=15), ovaries were removed and the rats were subjected to stress due to tooth preparation and surgical manipulation. Orthodontic appliances were placed after 14 days in groups 2 to 4. All groups except for group 1 were subjected to mesial movement of maxillary right first molar using NiTi closed coil spring applying 60g load for 21 days. The rats were sacrificed at 21 days and the amount of orthodontic tooth movement was measured using a feeler gauge. Data were analyzed using ANOVA.
    Results
    The mean orthodontic tooth movement was 1.18±0.2 mm in group 4, which was significantly greater than that in group 3 (0.47±0.18 mm) and group 2 (0.22±0.07 mm) (P
    Conclusion
    Absence of estrogen can significantly accelerate orthodontic tooth movement in rats.
    Keywords: Tooth Movement Techniques, Gonadal Steroid Hormones, Rats
  • Maryam Zare Jahromi, Elmira Ahmadpour Pages 92-97
    Background And Aim
    Researchers have been in search of medications with less side effects to relieve pain after root canal therapy. This study aimed to assess the efficacy of premedication with oral dextromethorphan and Ibuprofen to decrease pain after endodontic treatment.
    Materials And Methods
    This double blind clinical trial was conducted on 45 patients. The selected teeth had irreversible pulpitis and spontaneous pain with no periapical lesion. The patients were randomly divided into three groups of 15. One-session treatment was scheduled for them and after signing informed consent forms, the patients received a single dose of dextromethorphan, ibuprofen or placebo one hour preoperatively. The severity of pain was measured before and two, four, eight and 12 hours after endodontic treatment using a visual analog scale (VAS). Two endodontists performed the treatments. The data were analyzed using the Mann Whitney, Kruskal Wallis and Friedman test.
    Results
    The mean severity of pain in the dextromethorphan and ibuprofen groups was significantly different from that in the placebo group at the five assessment time points (P0.05).
    Conclusion
    The results showed that the analgesic efficacy of dextromethorphan and ibuprofen was equally greater than that of placebo.
    Keywords: Premedication, Analgesics, Root Canal Therapy, Pain
  • Soodeh Tahmasbi, Mahya Adhami, Azam Valian, Roya Hamedi Pages 98-103
    Background And Aim
    White spot lesions (WSLs) are common occurrence following orthodontic treatment, this study sought to compare the remineralizing potential of fluoride, MI Paste Plus (CPP-ACP-F) and Remin Pro for treatment of WSLs.
    Materials And Methods
    This in vitro study was conducted on 56 sound human premolars that extracted for orthodontic purposes. Teeth were cleaned and their roots were cut, then the crowns were mounted in acrylic resin. Teeth surfaces were coated with nail varnish except for a 3×4mm window on the buccal surface. In order to create WSLs, all samples were immersed in demineralizing solution for 10 days. After surface hardness was measured using a Vickers microhardness tester, teeth were randomly divided into four groups. In control group (group 1) no remineralizing agent was used while, groups 2 to 4, were treated with0.05% sodium fluoride (NaF), MI Paste Plus, and Remin Pro paste respectively, for five minutes every 12hours. After each treatment, specimens were immersed in freshly prepared artificial saliva. At the end of 28 days, surface microhardness was measured again and changes were statistically analyzed using analysis of covariance (ANCOVA).
    Results
    The mean changes in surface microhardness of MI Paste Plus, NaF and Remin Pro groups was significantly higher than control group (P˂0.001, P˂0.001 and P0.046 respectively).
    Conclusion
    MI Paste Plus, 0.05% NaF mouthwash, and to a lesser extent Remin Pro were efficient for treatment of WSLs comparing to the artificial saliva.
    Keywords: Dental Caries, Sodium fluoride, Mouthwashes, Therapeutics
  • Mohammad Sadegh Ahmad Akhoundi, Amirhossein Mirhashemi, Sedigheh Sheikhzadeh, Elahe Ansari, Yasaman Kheirandish, Nafiseh Momeni, Mohmmad Javad Khaarazifard Pages 104-109
    Background And Aim
    Considering the effect of alcohol on bones, consuming alcohol may have some consequences on orthodontic tooth movement. The present study was aimed to evaluate the effect of alcohol consumption on bone density and orthodontic tooth movement in rats.
    Materials And Methods
    In this experimental study, thirty rats were divided into three groups and underwent 3 weeks of different injection regimen. Group A received no injection while rats in group B and C were infused with saline and a mixture of alcohol and saline respectively. Tooth movement at day 21 was measured by leaf gauge. Optical density was measured using a digital densitometer at the beginning and the end of the experiment around four lateral cephalometric landmarks. One-way analysis of variance (ANOVA) was used to determine the differences in tooth movement. Changes in bone density were analyzed using paired T-test after evaluation of interactions.
    Results
    Mean tooth movement in group C was (0.4± 0.06 mm) was significantly higher than no injection (0.26 ± 0.04 mm) and saline infusion (0.29 ± 0.04 mm) groups (P=0.001). Significant decrease in bone density were observed in alcohol injected group in skull (P=0.005) and mandible(P=0.004) after three weeks of experiment.
    Conclusion
    Alcohol infusion could induce decreased bone density which might be a reason for faster tooth movement in alcohol-treated rats.
    Keywords: Ethanol, Bone density, Tooth, Rats
  • Mohammad Hashem Hosseini, Fatemeh Gorjizadeh, Ardavan Etemadi, Pedram Baghaeian Pages 110-117
    Background And Aim
    Application of zirconia ceramics has increased. Since the commonly used surface treatment for porcelain, i.e. acid etching is not efficient for zirconia surfaces, evaluation of other surface treatment methods for zirconia is important. The aim of this study was to compare the shear bond strength (SBS) of metal brackets to zirconia treated with different powers of Er:YAG laser, sandblasting and silane.
    Materials And Methods
    In this experimental study, five blocks of 3 mol% yttria stabilized tetragonal zirconia ceramics (3Y-TZP-A) were cut into small cubes. After the sintering process, 72 samples were assigned to six groups (n=12). The first group did not receive any surface treatment. The second, third and fourth groups were irradiated with Er:YAG laser with 1.5 W (150 mJ), 2.5 W (250 mJ) and 3 W (300 mJ) powers, respectively in a long pulse mode for 20 seconds. The samples in the fifth group were sandblasted. The sixth group samples were silanized. After bonding of brackets to the samples, they were stored in distilled water, thermocycled and their SBS was measured by a universal testing machine. Mode of failure was assessed by a stereomicroscope.
    Results
    The SBS of brackets to zirconia in groups one to six was 0.31±0.23, 0.51±0.14, 1.11 ±0.40, 3.32±1.52, 9.5±2.99 and 3.88±2.20 MPa, respectively. ANOVA revealed a significant difference among the six groups. Tamhane’s test showed that the SBS in group five was significantly higher than that in the other groups. Bond failure occurred at the adhesive/zirconia interface in all groups.
    Conclusion
    Surface treatment of zirconia with sandblasting provided appropriate bond strength of brackets for clinical applications. But, Er:YAG laser and silane did not create sufficient SBS to zirconia surfaces.
    Keywords: Lasers, Shear Strength, Orthodontic Brackets, Zirconium