فهرست مطالب
Journal of Dentistry, Shiraz University of Medical Sciences
Volume:18 Issue: 1, Mar 2017
- تاریخ انتشار: 1395/12/25
- تعداد عناوین: 12
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Pages 1-6Statement of the Problem: T cells have been shown to play a role in the etiopatho-genesis of periodontal disease. B7-H3, a costimulatory molecule, is found to be as-sociated with regulation of T cell function in some tumoral tissues, as well as auto-immune and inflammatory diseases.PurposeThe aim of this study was to investigate the expression of B7-H3 molecule in healthy and diseased gingival tissue samples.Materials And MethodGingival samples were taken from 2 groups (A and B) rep-resenting periodontal health and periodontal disease, respectively. These were paraf-finized and processed to carry out immunostaining to identify B7-H3 expression. The slides were then examined under light microscope to assess the positive staining in epithelium and connective tissue. The intensity of positive staining in epithelium and the number of positive cells in the connective tissue were evaluated. Statistical analysis was done using kappa analysis and independent t-test.ResultsKappa analysis revealed good inter-examiner agreement for both the groups (group A: 0.718; group B: 0.797). Intensity of staining in the epithelium ranged from intense to moderate for both the groups. In the connective tissue, there was a statistically insignificant decrease (p value= 0.415) in the number of positive cells from group A (mean labeling index: 50.28±26.09) to group B (mean labeling index= 41.37±25.29).ConclusionB7-H3 molecule has been found to be expressed in gingival tissue samples; however, it showed a statistically insignificant decrease in periodontal dis-ease group compared to healthy group.Keywords: B7, H3, Periodontitis, Immunohistochemistry
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Pages 7-16Statement of the Problem: Achieving a normal soft tissue facial profile is consid-ered to be the main concern of class III patients and the goal of most class III treat-ments.PurposeThe purpose of this study was to investigate the effects of facemask treat-ment on profile with photogrammetric method.Materials And MethodBefore (T0) and after (T1) treatment photograms of 40 class III patients profiles (20 male and 20 female individuals) treated with protraction face mask that met the inclusion criteria were digitized and analyzed using Aesthetic Analyzer software. Selected linear and angular measurements were performed for each patient and the changes were noted.ResultsAn increase in inferior facial height (pConclusionRemarkable advancement in the middle face and consequent fullness in the soft-tissue profile can be achieved by using protraction face mask. The response to treatment is not different between males and females.Keywords: Class III malocclusion, Dental photographs, Removable orthodontic Appliance
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Pages 17-23Statement of the Problem: Recurrent aphthous stomatitis (RAS) is one of the most common lesions in the oral cavity. Due to its multifactorial nature, there is no defini-tive treatment for RAS. Laser therapy is one of the suggested treatments to reduce patients discomfort.PurposeThe purpose of the present clinical trial is to assess the effect of low and high level laser therapy on pain control and wound healing of RAS.Materials And MethodThirty six patients with minor RAS were divided into three groups. Group 1 (n=14) received CO2 laser, group 2 (n=12) were treated with In-GaAlP Diode laser and group 3 (n=10) received sham laser as placebo. All patients were evaluated daily up to 15 days after receiving one session of laser therapy. Pain severity before and after treatment, wound healing, patients satisfaction, and func-tional disturbance before and after treatment were recorded for each patient.ResultsAccording to statistical analysis, pain reduction after treatment in group 1 was 7.00±2.41, in group 2 was 2.08±2.31, and in group 3 was 1.40±1.77. In addition, a significant difference was observed in the reduction of functional complications in CO2 laser treated patients compared to the other two groups.ConclusionHigh-level laser treatment showed analgesic effects on RAS, but no healing was observed. Low-level laser therapy demonstrated no positive effect on recurrent aphthous ulcers.Keywords: Aphthous, Stomatitis, Laser therapy, Wound healing
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Pages 24-29Statement of the Problem: The maintenance of viable periodontal ligament cells is the most important issue in the long-term preservation of avulsed teeth.PurposeThe aim of this study was to assess aloe vera as a new storage media in maintaining the cell viability of dry-stored teeth in comparison with soy milk, Hank`s balanced salt solution (HBSS), and milk.Materials And MethodTwenty one extracted dog premolar teeth were dried for 30 minutes and stored in soy milk, HBSS, milk, and aloe vera extract (50%) for 45 minutes (n=6 for each). Furthermore, positive and two negative control groups (n=6), corresponding to 0 min, 30 min, and 2-hour drying times were also prepared respectively. The number of viable cells was counted following storage using Trypan blue exclusion. Data were statistically analyzed using the one-way ANOVA and post hoc Tukey-HSD test.ResultsStatistical analysis showed no significant differences in cell viability among aloe vera, soymilk, and HBSS- stored teeth; however, they were all superior to milk.ConclusionAloe vera extract can be recommended as a suitable storage media for avulsed teeth.Keywords: Aloe vera, Cell viability, Periodontal ligament, Soy milk, Tooth avulsion
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Pages 30-36Statement of the Problem: Increasing the thickness of the veneering porcelain may affect the polymerization of resin cements. Incomplete polymerization of resin cements can lead to compromised quality of restoration and decrease the longevity of indirect restorations.PurposeThis study sought to assess the effect of IPS Empress porcelain thickness on the degree of conversion of light-cure and dual-cure resin cements using Fourier transform infrared spectroscopy.Materials And MethodIn this experimental study, IPS Empress porcelain discs (A2 shade) with 10mm diameter and 0.5, 1 and 1.5 mm thicknesses were fabricated. Choice2 (Bisco, USA) and Nexus3 (Kerr, USA) resin cements were light cured through the three porcelain thicknesses in two groups of 3 samples using a LED light-curing unit (LEDemetron II; Kerr, USA). The control group samples were cured individually with no porcelain disc. The degree of conversion of resin cements was determined using FTIR (Bruker; Equinox55, Germany). The data were analyzed using Dunns test.ResultsThe degree of conversion (in percent) beneath the 0.5, 1.5 and 2 mm thicknesses of IPS Empress was 68.67±0.88, 71.06±0.94 and 72.51±0.41 for Choice2 resin cement and 69.60±2.12, 69.64±1.63 and 69.24±2.12 for Nexus3, respectively. Porcelain thickness and type of resin cement had no significant effect on degree of conversion (p≥ 0.05).ConclusionIt seems that increasing the porcelain thickness by up to 1.5 mm has no adverse effect on degree of conversion of both dual cure and light cure resin cements evaluated in this study.Keywords: Resin Cements, Polymerization, Spectroscopy, Fourier Transform Infrared, Ceramics
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Pages 37-42Statement of the Problem: Various researchers have suggested the use of β2-adrenergic receptor antagonists in prevention or treatment of bone resorption.PurposeThis study aimed to evaluate the effect of β2-adrenergic receptor antagonists on number of osteoclasts and osteoblasts involved in the healing of extraction socket of maxillary first molar in rats.Materials And MethodMaxillary first molars of 40 rats were extracted and divided into two groups. The test group received 0.1 mg/kg propranolol intraperitoneally daily. The controls received normal saline. At days 7, 14, 21 and 28 post-extraction, 5 rats were euthanized from each group. Maxillary bone was resected and the mean number of osteoblasts and osteoclasts in tooth socket was measured.ResultsAfter 1 week, the number of osteoclasts in the controls was significantly higher than the test group. A significant increase in the number of osteoclasts in both groups at week 1 was observed compared to the following weeks (pConclusionβ2 adrenergic receptor antagonists decrease the number of osteoclasts and increase the number of osteoblasts during extraction socket healing.Keywords: Osteoclast, Osteoblast, Propranolol, Alveolar bone, Rat
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Pages 43-49Statement of the Problem: Odontogenic keratocyst (OKC) is a developmental odontogenic cyst with specific histopathological features, high recurrence rate, and aggressive clinical behavior. Angiogenesis might be considered as an important factor for the growth, expansion, and distribution of this lesion.PurposeThe aim of the present study was to determine the mean vascular densities (MVD) of OKCs and dentigerous cysts to evaluate their relationship with the biologic behavior of these lesions.Materials And MethodIn this cross-sectional analytical study, angiogenesis was assessed in OKC and dentigerous cyst by measuring the MVD. Immunohistochemistry was carried out using CD34 and CD105. The results were analyzed with independent samples t-test. The data were analyzed, setting p value at 0.05.ResultsThe MVDs with the use of CD34 and CD105 markers were significantly higher in OKC compared to dentigerous cyst (pConclusionBased on the results of the present study, it can be suggested that angiogenesis might be one of the possible mechanisms involved in higher aggressive biologic behavior and greater recurrence rate of OKC compared to dentigerous cysts.Keywords: CD105, CD34, Dentigerous cyst, Immunohistochemistry, Odontogenic keratocyst
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Pages 50-55Statement of the Problem: Porcelain laminate veneer is an esthetic restoration used as an alternative to full veneer crowns and requires minimal tooth preparation. In restoration with porcelain laminate veneers, both the longevity of the laminate and conservation of the sound tooth structure are imperative.PurposeThe present study aimed to investigate the shear bond strength of porcelain laminates to prepared- and unprepared- anterior teeth in order to compare their longevity and success rate.Materials And MethodThirty extracted maxillary central incisors were randomly divided into 3 groups regarding their preparation methods. The preparation methods were full-preparation in group A, full-preparation and finishing with fine diamond bur in group B, and no-preparation, only grinding with diamond bur in group C. After conditioning the teeth, ceramic veneers (IP S e.max) were silanated and then cemented with DuoLink luting cement. The shear bond strength was measured for each group and failure mode was determined by stereomicroscopic examination.ResultsGroup C exhibited the highest shear bond strength. The shear bond strength was significantly different between groups C and B (p 0.05). Adhesion failure mode was found to be more common than the cohesive mode.ConclusionRegarding the shear bond strength of unprepared anterior teeth to porcelain laminate veneers yielded by this study, no-preparation veneers might be used when the enamel is affected by wearing, trauma, or abrasion. It can also be used in patients who refuse the treatments which involve tooth reduction and preparation.Keywords: Dental veneer, Dental porcelain, Dental laminate, Dental bonding, Shear strength, Tooth preparation
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Pages 56-60Statement of the Problem: Endodontic irrigants and medicaments may affect the bond strength of intracanal posts to root dentin.PurposeThe aim of this study was to compare the effect of calcium hydroxide (Ca(OH)2) and 2% chlorhexidine gel (CHX) on bond strength of fiber post cemented with resin cement to root dentin.Materials And MethodThis in vitro experimental study was conducted on 36 mandibular premolars. Canals were prepared using the step back technique. After root canal irrigation, the teeth were divided into three groups of 12. Ca(OH)2 paste and CHX gel were used as intracanal medicaments in the first and second groups respectively. No intracanal medicament was used in the third group (control group). Access cavities were then sealed and the teeth were incubated for one week. The root canals were then filled using gutta percha and AH26 sealer and the teeth were incubated for 72 hours. Tooth crowns were then cut at the level of the cementoenamel junction and intracanal posts were placed. The teeth were mounted in auto-polymerizing acrylic resin, and incubated for one week .They were then sectioned into 1.5mm thick slices from their coronal surface using a fully automated cutting machine, and subjected to push-out test until failure. The load at debonding was recorded and data were analyzed using one-way ANOVA, post-hoc test and t-test. The coronal margin of the root was at the level of the surface of acrylic resin in the mold.ResultsThe mean bond strength was 4.45 MPa in the Ca(OH)2, 2.45 MPa in the CHX and 2.48 MPa in the control group. The difference in this regard was statistically significant among groups (p= 0.04). The Ca(OH)2 group had significant differences with the CHX and control groups (p= 0.03 and p= 0.02, respectively). The difference between the CHX and control groups was not significant (p= 0.974).ConclusionBased on the results, Ca(OH)2 increased the bond strength of fiber post to root dentin but 2% CHX had no effect on bond strength.Keywords: Chlorhexidine, Calcium Hydroxide, Fiber Post, Resin Cement
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Pages 61-64Statement of the Problem: Candida species are believed to play an important role in initiation and progression of denture stomatitis. The type of the denture material also influences the adhesion of candida and development of stomatitis.PurposeThe aim of this study was comparing the adherence of candida albicans to the conventional and injection molding acrylic denture base materials.Materials And MethodTwenty injection molding and 20 conventional pressure pack acrylic discs (10×10×2 mm) were prepared according to their manufacturers instructions. Immediately before the study, samples were placed in sterile water for 3 days to remove residual monomers. The samples were then sterilized using an ultraviolet light unit for 10 minutes. 1×108 Cfu/ml suspension of candida albicans ATCC-10231 was prepared from 48 h cultured organism on sabouraud dextrose agar plates incubated at 37oC. 100 μL of this suspension was placed on the surface of each disk. After being incubated at 37oC for 1 hour, the samples were washed with normal saline to remove non-adherent cells. Attached cells were counted using the colony count method after shaking at 3000 rmp for 20 seconds. Finally, each group was tested for 108 times and the data were statistically analyzed by t-test.ResultsQuantitative analysis revealed that differences in colony count average of candida albicans adherence to conventional acrylic materials (8.3×103) comparing to injection molding acrylic resins (6×103) were statistically significant (pConclusionSignificant reduction of candida albicans adherence to the injection acrylic resin materials makes them valuable for patients with high risk of denture stomatitis.Keywords: Candida albicans, Acrylic Resins, Denture
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Pages 65-69The main objective of this case report is to present a rare root canal configuration of maxillary molar with seven root canals; three mesiobuccal, two palatal and two distobuccal canals diagnosed during treatment procedure confirmed by spiral computed tomography. A thorough knowledge of root canal morphology, proper clinical and radiographic examination, and use of dental operating microscopes are necessary for successful clinical outcomes. This article highlights the variations in the morphology of maxillary first molar and use of the latest techniques in successful diagnosis and negotiation of the additional canals.Keywords: Maxillary First molar, Root Canal Morphology, Spiral Computed, Tomography
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Pages 70-70The congenital gingival granular cell tumor (CGCT), also as known as congenital epulis, is an unusual benign oral mucosal lesion in newborns. A two-day-old female patient was admitted to the Department of Pediatric Dentistry at Gulhane Medical Academy, Ankara, Turkey with her family, and an intraoral examination showed a CGCT located in the buccal region of the maxillary right first primary molar. In this report, we present a case of CGCT in a newborn.Keywords: Congenital epulis, Newman tumor, Oral mucosa