Journal of Dentistry
Year:2012 | Volume:- | Issue:SUPPLEMENT|Papers Count:16

Changed from previous version of American Heart Association guidelines for Infectious Endocarditis prevention, modified indications for antibacterial chemotherapy are highlighted. Such modifications are mainly derived by evidence-based medicine. A proper evaluation, consultation and antibiotic prescription may prevent unnecessary antibiotic administration and its consequences in terms of antibiotic resistance and economic burden.

Statement of Problem: Nowadays, fissure sealants are commonly used for sealing the occlusal pit and fissures. However, flowable composites which are more resistance to wear and have a lower amount of shrinkage might be a good substitute for sealants.Purpose: The aim of this study was to compare the amount of micro-leakage between two types of fissure sealants, clinpro and embrace, and two kinds offlowable composites, Filtek flow and Flows-Rite.Materials and Method: 60 intact extracted maxillary permolars were selected and divided into 4 groups. In each group, occlusal fissures of the samples were sealed with fissures sealants (clinpro or Embrace) or flowable composites (Filtek flow or Flows-Rite). The apex and furcation of all the teeth were sealed by sealing wax and then the root and crown of the samples were covered by two layers of nail varnish to I mm next to the sealant margin. The teeth were immersed in 0.5% fuchsine for 24 hours; then, the teeth were washed and. cut off parallel to the linear axis. The micro leakage of the samples was studied under the stereomicroscope with a magnification of l6x. Finally, data were analyzed using the Kruskal- Wallis test.Results: There was no significant difference between the amount of micro leakage of fissure sealants (clinpro and embrace) and flowable composites (filtek flow and Flows-Rite).Conclusion: Under the circumstances of this study and with respect to the clinical situation, it seems that both flowable composite and fissure sealants are suitable materials for pit and fissure sealing.

Statement of Problem: Several lines of evidence have indicated that IL- 17 might be important in the pathogenesis of RA and chronic periodontitis. IL-17 could be secreted primarily by T-helper cells.Purpose: The purpose of this study was to evaluate periodontal status of rheumatoid arthritis patients and its correlation with serum level of IL-17 in comparison to chronic periodontitis patients.Materials and Method: In the present case-control study, serum level of 11-17 was determined by Eliza technique using PCR-RFLP method in 142 RA patients and 106 control subjects. Specific measures for periodontitis included probing pocket depth (PDD), clinical attachment level (CAL). Bleeding score (81) and plaque score (PI) were also assessed and compared in the two groups.Results: No significant association was found between different paraclinical findings (including CRP, RF, ESR) and age of the onset of RA. The highest level of IL-17 was found in RA patients with moderate to severe periodontitis (p =0.013). The prevalence and severity of periodontitis were higher in the test group. In the present study, Kruskal- Wallis test was used for evaluation of serum level of IL-17.Conclusion: The findings of the present study suggest that rheumatoid arthritis patients are prone to severe periodontitis and the level of IL-17 in the serum is positively associated with severity of periodontitis.

Statement of Problem: Absence of marginal integrity is one of the most important problems in the fixed restoration treatments.Purpose: The aim of this study is to compare the effect of conventional and electroforming methods on the marginal integrity at PFM restorations.Materials and Method: In this experimental study, after preparing the metal standard die and molding, 20 plaster dyes were prepared and then randomly divided into two groups of ten each. PFM crowns were prepared using the conventional method in the first group and electroforming method in the second group. After cementing the samples on the die and mounting in transparent resin and grating, all the samples were observed in the electron microscope. Then, the data were analyzed using t-test.Result: The mean marginal discrepancy and SD was 11.16 ± 1.28 micron in the first group and 3.13 ± 0.79 micron in the second group. T -test results showed that the differences between the two groups were significant (p<0.05).Conclusion: According to the result of this study, marginal adaptation in electroforming crowns is better than casting crowns.

Statement of Problems: Herpes Simplex type 1 (HSV -1) is associated with different human infections including oral infection. Acyclovir is used for the treatment of such herpetic infections. However, acyclovir resistant HSVs are increasing nowadays due to the lack of thymidine kinase activity in HSV mutants. So, research on alternative treatment is urgently required.Purpose: The aim of this study was to examine the effect of essential oil of Zataria multiflora Boiss on herpes simplex type 1 in Vero cell culture.Materials and Method: The essence of Zataria multiflora was prepared by the clevenger apparatus and used for the experiments in Vero cell culture. Cytotoxic effect of increasing concentrations of the essence from 0.001-0.02% was assessed on Vero cell line and antiviral effect of the essence was studied in Vero cells, using plaque reduction method. The data were analyzed by one way ANOV A using SPSS, version 17.Results: The 50% cytotoxic concentration (CC50) of Zataria multiflora essential oil for Vero cells and 50% inhibitory concentration (IC50) were 0.067% and 0.0059%, respectively. Compared to the controls, all the above used concentrations had the inhibitory effect on HSV -1 (p <0.05). Concentrations of 0.1- 0.2% showed a complete anti-HSV -1 inhibitory effect.Conclusion: The results of this study showed that essential oil of Zataria multiflora Boiss has a significant inhibitory effect on HSV -1, so it may be used as an anti-herpetic mouthwash candidate for the control of oral HSV infections. However, in vivo studies might be necessary for determining its exact toxic effects on human cells.

Statment of Problems: Although the primary use of tissue conditioners is for healing the damaged mucosa but they can also be used as functional impression; it seems that its effeicasy depends on its viscoelastic features such as compatibility with gypsum and surface roughness.Purpose: The aim of this study is to compare the surface roughness of gypsum with several tissue conditioner impression materials avaliable in the market.Materials and Method: In this experimental study, three tissue conditioners (Acrosoft, viscogel & GC) were used. Pars dental gypsum moldano Type III and a polyvinyl siloxane impression were used for the controls. The tissue conditioners powder liquid ratio was mixed according to the manufacturer's recommendation and immediately poured in a mold with an internal diameter of 18 mm and depth of 2mm. The mold was completely filled. Then, a glass block with the mean roughness of 0.8 mm was placed on its surface for two hours. Then, the 5 samples were immediately placed in 37oC water for 0-24 hrs, 3, 7, and 14 days. After that, the specimens were beaded, boxed and poured with pars dental gypsum type III. The gypsum sample's surface roughness was measured with profilometer with the length of 2.5 mm and cut-off of 0.8 mm. The results were analyzed using ANOV A and Tukey tests.Results: The results showed that surface roughness of Acrosoft in different storage times did not change.significantly and there was no significant difference between Acrosoft and the control group. Viscogels surface roughness was significantly different with all other groups at zero time; with the increase of storage time the surface roughness decreases. The control group showed a significant difference with viscogel at zero time and with GC at 24 hrs and 3 days but it revealed no difference with the other groups. The least surface roughness belonged to GC at zero and 14 days and the highests surface roughness belonged to viscogel at zero time.Conclusion: Surface roughness depends on the chemical structure of the material. The best time for pouring with tissue conditioners for functional impression is 24 hrs to 3 days after making impression. Acrosoft had no significant difference with the control groups at any time.

Statement of Problem: Everyday, many people lose their teeth because of various reasons. Knowing the reasons of tooth extraction would help officials to make decisions for helping patients saving their teeth.Purpose: The aim of this study was to investigate the reasons of teeth extraction in dental clinics and some private offices in the city of Kerman in November 2009- February 2010.Materials and Method: in this cross-sectional study, the reasons of teeth extraction III 2076 teeth from 1500 patients selected by simple sampling from Kerman dental clinics were evaluated. Personal data such as gender, age, educational level, occupation, and family size as well as the main reason of tooth extraction (decay, periodontal diseases, prosthesis, tooth impaction, orthodontic reasons, and patient's request) and the type of tooth were collected by a checklist. Data were analyzed in SPSS, version 11.5 using t test.Results: The two main reasons of tooth extraction were dental caries (43.6%) and patient request (30.6%), respectively. Overall, the first and third molars of the lower jaw were the most commonly extracted teeth. There was a significant relationship between gender and tooth extraction because of caries and orthodontic reasons (p<0.0001). Meanwhile, the patients' age had a significant relationship with most teeth extraction reasons (p<0.0001). Except for patient's request, educational level had a significant impact on other teeth extraction reasons (p<0.0001).Conclusion: According to the results of this study, the most common reasons of tooth extraction were dental caries and patient request despite their restqrability. Preventive programs and routine dental examination are recommended.

Statement of Problem: Periodontitis is a chronic multi-factorial infectious disease, characterized by irreversible destruction of collagen fibers and other matrix constituents of the gingival tissues, periodontal ligament and resorption of the alveolar bone around the teeth with formation of periodontal pocket. Cytokines such as IL-I p are one of the components of host's immune system and seem to play an important role in periodontitis.Purpose: The aim of this study was to determine the concentration of IL-1b as a per-inflammatory cytokine in the saliva of periodontally involved patients (generalized aggressive periodontitis and mild to moderate periodontitis) and subjects with normal periodontium.Materials and Method: In this experimental study, unstimulated saliva of 24 patients with mild to moderate chronic periodontitis, 15 patients with aggressive periodontitis, and 23 subjects with healthy periodontium was collected. The concentration of IL-1b was measured in the saliva samples by ELISA. Mann-Whitney test was used for analysis of data.Results: The results of this study showed that there was a significant difference between mean level of IL-1b in generalized aggressive periodontitis vs. control groups and chronic mild to moderate periodontitis vs. control groups (p<0.05).Conclusion: The findings of the present study showed that the mean concentration of IL-1b in the saliva of periodontally involved patients was greater than that of healthy subjects and this cytokine can be agood marker for determining the status of periodontal tissues.

Statement of problem: Sella turcica is an important anatomical structure in radiographic analysis of neurocranial and craniofacial complex and also it is important in orthodontics, because sella is a usefual landmark in lateral cephalometric analysis. Alteration in the size and shape of sella turcica can be considered as a pathologic procedure. These alterations can also occur in some syndromes and craniofacial abnormalities.Purpose: The aim of this study was to evaluate and determine the size and. shape of sella turcica in patients with normal, low and high facial height.Material & Methods: In this retrospective study, 300 files of patients who reffered to orthodontics clinic of Shiraz dental school were evaluated. The patients' mean age was 17.33±lAO years. At first, lateral cephalograms were scanned and then analyzed with lighting ceph software. Then, the size of sella was evaluated using autocad software and finally the shape of sella was determined according to standard references. Data were analyzed using Chi-square and ANOV A tests in SPSS, version 16.Results: This study showed that shape and size of sella turcica change in patients with normal, low and high facial height but these changes are not significantly different (p>0.05).Conclusion: According to the results of this study, it seems that alteration in the size and shape of sella turcica can be affected radiographicaly by malocclusions of different facial dimensions and dental and craniofacial abnormalities.

Statement of Problem: Reducing oral microorganisms before the oral and maxillofacial surgery, which are accomplished through the mouth, can play an important role in reducing the occurrence of infections after surgery. One effective method in reducing the number of microorganisms is the use of antiseptic mouthwash.Aim: This study was conducted to compare the antimicrobial and cytotoxicity activity of Chlorhexidne, Irsha, oral B, Biothene, Povidone iodine, Benzidamine and Camomile mouthwashes.Methods and Materials: This is an experimental study in which lactobacillus casei, Candida albicans, Streptococcus mutans, Streptococcus viridance and Streptococcus sunguis were cultured. For each bacterium, the concentration of 0.5 MC farland was prepared. Four concentrations (5%, 1%, 0.5%, 0.1 %) of mouthwashes were also prepared. Distilled water was used as negative control. Tukey, and One Way ANOVA, in SPSS, version 17, were used to analyze the data. Also, to evaluate the cell cytotoxicity of the Mouthwash, colorimetric MTT- Colorimetric assay ([3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide]) was used.Results: The results showed that nystatin was the most effective mouthwash on Candida albicans. Irsha, povidone iodine and benzidamin had no antifungal effect. Only at concentrations of 0.1 %, the mouthwash had no antifungal effect but in other concentrations it had. Chlorhexidine had the most antimicrobial effects. The oncentration of 5% Benzidamine and Irsha had a significant effect on HEPG2, MRF, Saos-2 and KB. The concentration of 5% Povidone iodine mouthwash had a cytotoxicity effect on HEPG2, MRF and 1774.A 1 and I % concentration had an impact on Saos-2 cells. Camomile mouthwash was effective on the cell MRF in concentration of 5% and oral B mouthwash was effective: on HEPG2 in the same concentration. Chlorhexidine mouthwash had lower cytotoxic effects on all cell lines.Conclusion: The results of this study showed that chlorhexidine mouthwash had better antimicrobial properties and cytotoxicity as compared to others and is recommended as a good mouthwash to be used by patients.

Statement of Problem: In most cases of periodontal therapy, antibiotics are suggested as an adjuvant. It is necessary to evaluate the effect of systemic administration of antibiotics in treatment of periodontal diseases and introduce a cost-effective method for management of periodontal infections in individuals who have no access to periodontal therapy.Purpose: This study aimed to compare the effect of antibiotics alone, scaling and root planing (SRP) alone or SRP combined with antibiotics as gold standard approach in improvement of PPD of patients with chronic periodontitis.Materials and Method: This was an experimental study conducted on 44 patients with chronic peridontitis. They were randomly assigned to three groups as follows: 1- SRP Group receiving scaling and root planing alone. 2- AB Group that received antibiotic. 3- Combination Group that received SRP and antibiotic. Clinical measurements including probing depth (PPD), gingival bleeding index (GBI) and plaque index (PI) were performed at base line and 3 months after the treatment. Statistical analyses were performed using covariance analysis kolmogrove- smimov test and ANOYA test.Results: All 3 groups showed a significant reduction in PPD, GBI and PI 3 months after treatment (p <0.05 in all 3 groups) Improvement in PPD measures in the combination group was statistically significant (p =0.0001). The difference between the groups was not significant with respect to GBI reduction (p >0.05).Conclusion: In chronic periodontitis, systemic antibiotic therapy alone was as effective as mechanical therapy alone in reduction of PPD, but systemic administration of antibiotic in combination with scaling and root planning showed the most improvement in PPD measures.

Statement of Problem: E-cadherin is an inetrcellular adhesion molecule playing the important role in cell to cell adhesion in the epithelium. b-catenin is a cytoplasmic protein that directly binds to E-cadherin to connect it to the cytoskeleton. The first step in invasion of cancerous cells to adjacent tissues or metastasis is reduction of adhesion between tumoral cells.Purpose: The purpose of this study was to determine therelationship between different grades of see with expression rate of E-cadherin and b -catenin and also to identify the correlation of expression of these markers with each other.Materials and Method: The sections of 60 formalin-fixed, paraffin-embedded biopsy specimens including 20 well differentiated, 20 moderately differentiated and 20 poorly differentiated squamous cell carcinoma were immunostained to determine the expressions of E-cadherin and p-catenin. Mann-whitney, Kruskal- Wallis and Wilcoxon tests were used to analyze the data.Result: The difference of the expression of E-cadherin and p-catenin was statistically significant in different grades of see (p<0.001). But comparison of the expression of these markers in any histological grade separately did not show a significant difference (p>0.05). Although regardless of differential grade of the tumor, expression of p- catenin was significantly entirely different from E-cadherin overally (p =0.015).Conclusion: These findings suggested that expression of E-cadherin and p-catenin reduced in proportion to reduction of differential grade of see and also reduction of the expression of E-cadherin and p-catenin was proportional to each other, although regardless of the degree of differentiation, expression of p-catenin was totally less than that of E-cadherin.

Statement of Problem: Labial access cavity preparation is a conventional method in endodontic treatment of the anterior teeth, but in some conditions labial cavity preparation is recommended.Purpose: The aim of this study was to compare labial and lingual access cavity preparation III the permanent anterior teeth with labial caries in terms of the remaining tooth structure and fracture resistance.Materials and Method: In this experimental study, 150 intact permanent human anterior teeth were selected in 5 groups each with 30 teeth including the maxillary central, maxillary lateral, maxillary canine, mandibular incisors and mandibular canine. A class V cavity with similar ratios to dimensions of each tooth was prepared on the labial surface of all specimens. The volumes of each of these teeth were measured by Penta Pycnometer before and after class V cavity preparation (VI, V2). Each group was randomly divided into 2 equal subgroups (n=15). Access cavities were prepared labially in subgroup A and lingually in subgroup B; then, the remained volume of each tooth was measured again (V3). The mean proportional volume loss of each tooth was calculated through access preparation (V2-V3Nl). Then, the specimens were embedded in acrylic resin blocks and subjected to load with a universal testing machine.Results: The differences of mean of theremained volume and fracture resistance of the two subgroups were statistically significant in all groups (p <0.05) and those teeth with labial access showed more remained volume and fracture resistance than lingual access.Conclusion: Labial access cavity preparation can enhance the remained volume and fracture resistance as compared to lingual access in endodontic treatment of the anterior teeth with labial caries especially in mandibular incisors.