Journal of Dental Medicine
Year:2017 | Volume:30 | Issue:1|Papers Count:12

Background and Aims: Taking impression from angulated implants has always been a great challenge in clinic. In this regard, studies on sectional trays are very few. The aim of this study was to evaluate and compare the dimensional and angular accuracy of impressions using full arch and sectional trays.Materials and Methods: Four implants (4.3×12 mm) (Implantium, Dentium) were placed in the first premolar and molar regions of a Kennedy class I mandibular acrylic model with 30° lingual angulation. Twenty open special trays (Full arch & Sectional) were made on the primary cast. The impressions were taken using vinyl polysiloxane (VPS) and were poured with type IV dental stone. The coordinate measuring machine (CMM) was used to measure the dimensional (Z, Y, X) and angular (q) coordinates of implants. The data were analyzed using and t-test and SPSS 22. Software.Results: The type of tray had no significant effect on the dimensional accuracy in X, Y and Z axes (P>0.05) and total linear displacement (r); However, it significantly affected the angular accuracy (Dq) (P<0.05).Conclusion: Sectional tray yields less rotational displacement in impressions made of angulated implants.

Background and Aims: Tooth decay has high prevalence in the world. The use of plant material for the prevention and treatment of this disease for various reasons is considered, due to the increasing resistance of bacteria to antibiotics, the high cost and adverse effects of some chemicals used in dentistry. This study was aimed to determine the antimicrobial effect of alcoholic extract of Pepper (Capsicum annuum) and eggplant skin and cap on the cariogenic streptococci.Materials and Methods: In this study, the antimicrobial activity of ethanol extract of Capsicum annuum and eggplant skin and cap on the cariogenic streptococci, including Streptococcus mutans, Streptococcus sobrinus, and Streptococcus sanguis by microtitre plate method for MIC (Minimum Inhibitor Concentration) was performed. Data were analyzed by one-way analysis of variance using Prism 5 Graph Pad software.Results: MIC for the Capsicum annuum and eggplant skin for Streptococcus mutans was 250 mg/ml (SD=0.052), and for the Streptococcus sobrinus and Streptococcus sanguis was 125 mg/ml (SD=0.027). The MIC for the cap eggplant for Streptococcus mutans and Streptococcus sobrinus was 500 mg/ml (SD=0) and for S. sanguis was getting 125 mg/ml (SD=0.159).Conclusion: This study showed that the herbal extracts of Capsicum annuum and eggplant skin and cap had beneficially antimicrobial effects on all three strains of cariogenic streptococci.

Background and Aims: There is an increased risk of periodontal diseases in patients undergoing fixed orthodontic treatment. Chlorhexidine (CHX) is frequently used to promote oral hygiene; however, it is associated with several complications. Herbal mouthwashes can be used as the substitute without having similar complications. The aim the present study was to compare the effects of herbal mouthwashes (Matrica and Persica) with CHX 0.2% on the periodontal parameters of patients under fixed orthodontic treatment.Materials and Methods: In a double-blind randomized clinical trial, 84 patients under fix orthodontic treatment were selected. After receiving oral hygiene instruction, the patients were randomly assigned to four groups (group 1: Matrica, group 2: Persica, group 3: CHX 0.02%, group 4: normal saline). Dental plaque scores (PI), gingival inflammation (GI) and papillary bleeding (PBI) indices were measured at the beginning, 1 week after receiving oral hygiene instructions and 30 days after mouthwash consumption. The scores of the periodontal indices were statistically analyzed by Kruskal Wallis, ANOVA the paired Mann-whitney U test and Tukey test.Results: All of the indices were significantly reduced in study groups (except for the control). Matrica and Persica mouthwashes were similarly effective in improving the periodontal parameters. Their efficacy in decreasing the PBI scores was significantly higher than CHX 0.2% (P<0.01).Conclusion: Application of the two herbal mouthwashes was effective in improving the periodontal parameters in patients undergoing fixed orthodontic treatment.

Background and Aims: The exact placement of impression copings in making accurate prosthesis is very important. In some cases, the implants need to be placed deeply subgingival, which could reduce the direct vision and ultimately reduce the precision of impression copings and subsequently, delivered prosthesis. This would be the cause of multiple complications such as delivery of ill-fitting prosthesis. The aim of this study was to evaluate the effect of the dental implant placement depth on the accuracy of impression coping connection by students.Materials and Methods: This in-vitro and experimental study was conducted by 50 senior dental students. Four implants at different depths (0, 2, 4 and 6 mm) were placed in a model. After learning how to mount impression coping on implants, the students were asked to mount impression copings on all four implants. The samples were examined by an experienced prosthodontist using a magnifier with 4x magnification. Data were analyzed by statistical Cochran test (P<0.05).Results: The proper adapting rate of transfer copings, in subgingival implants with the depth of 0, 2, 4 and 6 mm were 100%, 62%, 58% and 20%, respectively. Statistically significant differences were observed between all groups (P<0.001).Conclusion: The results showed that there was an inverse relationship between the increasing depth of the implants in the gingiva and the dentist’s ability to connect the impression copings properly.

Background and Aims: Cervical tooth hypersensitivity (CTH) is defined as a sharp pain of short term that occurs in dentin exposed to the oral environment. The aim of this study was to evaluate the efficacy of a desensitizing toothpaste containing potassium nitrate (Sensodyne®) for relieving of CTH, when used locally or as tooth paste.Materials and Methods: 36 patients were enrolled in this study. They were randomly divided into three groups I) Tooth brushing without toothpaste, II) Local application of toothpaste containing potassium nitrate 5%, III) Tooth brushing with toothpaste containing potassium nitrate 5%. Assessment of CTH was done by evaporative (using air and water spray) and cold stimuli at baseline, 1, 3, and six weeks after the treatment. To compare pain changes over time, due to the interaction between the variables of the studied groups and time, one-way ANOVA was used at any time. Due to the difference of variance between groups to compare pairs of groups, Dunnett T3 test was used.Results: During the study period, no adverse event observed. In all three groups, pain decreased gradually. Local application of toothpaste had the most favorable effect on CTH. Therefore, when compared with that of the first group, the percentage reduction in pain were statistically significant (P=0.03).Conclusion: Local application of toothpaste containing potassium nitrate as a desensitizing ingredient is a better choice for treatment of CTH than that of application with toothbrush.

Background and Aims: Opinion of students regarding the content, structure and quality of their training is a fundamental part of holistic evaluation of curriculum, and serves as an important information resource in policy making. In the present study, we aimed to contribute to the development, assessment and evaluation of the new national dental curriculum through evaluation of last-year dental students’ opinions regarding undergraduate dental curriculum.Materials and Methods: This cross sectional questionnaire survey was done in 2010-2011 academic year. The target population was last-year dental students in 15 Iranian state dental schools. In these schools, all last-year dental students were invited to participate in the study. The chi-square test served for statistical analyses.Results: In total, 432 students (68.4% female) participated in the study. Of the respondents, 72.4% (60.7% of male and 77.6% of female, P=0.001) believed that their undergraduate dental training had been completely inadequate or inadequate. Only about one third of students believed that educational methods during their undergraduate dental training had been appropriate or completely appropriate.Conclusion: In general, it seems that undergraduate dental training from students’ view point has not been appropriate in terms of both content and method. The results show the necessity of revision of national undergraduate dental curriculum.

Background and Aims: Trauma to the permanent and deciduous incisors is an undesirable common event in childhood. Proper immediate management of injured teeth is depended on the knowledge of unprofessional people, including teachers, who are usually present at the scene prior to dental treatment. The aim of this study was to assess the knowledge and self-reported practice of primary school teachers on the emergency management of traumatic dental injuries (TDIs) in Arak.Materials and Methods: In this cross-sectional study, 624 primary school teachers were enrolled in census in Arak. An anonymous questionnaire containing demographic data, the history of previous exposure to traumatic dental injuries, teachers’ knowledge regarding emergency management of TDIs and their practice towards TDIs was used. Questionnaires were distributed among all participants and then were collected on the same day. Descriptive statistics and linear regression were performed to analyze the data.Results: A total of 292 completed questionnaires (response rate 46.8%) were collected. The mean score of knowledge was 2.65±1.69 out of 10. The mean score of self-reported practice was 3.46±2.04 out of 8. Regarding the demographic variables, knowledge had a significant relationship with the education (P<0.001). No significant relationships were observed between the self-reported practice and demographic variables. The correlation coefficients between the knowledge scores and the practice scores of teachers was 0.2.Conclusion: This study revealed that insufficient knowledge exists among primary school teachers on emergency management of TDIs. Furthermore, a high percentage of respondents enjoy a significant deficiency regarding favorable practice encountering TDIs.

Background and Aims: Dental caries is an infectious disease transmitted by multiple factors in the mouth and one of the most common chronic diseases in the world that requires a lot of treatment expenses. The aim of this study was to evaluate the effect of fluoride 0.2% and Fuchs mouthwash (a combination of xylitol and fluoride 920 ppm) against two bacterial growths (Streptococcus mutans and Lactobacillus acidophilus).Materials and Methods: In this in vitro study, first the well diffusion method and then MIC method (minimum inhibitory concentration) were used. Data were analyzed with Excell (2016).Results: The results of the MIC method showed inhibitory effect of both mouthwashes in pure concentration (128 mg/ml). However, fluoride was effective in concentration higher than 32 mg/ml for Streptococcus mutans and higher than 2 mg/ml for lactobacillus acidophilus. Fuchs was effective for both bacteria at concentration higher than 64 mg/ml and in lower concentration it was ineffective. The results of the well diffusion test showed the inhibition of fluoride mouthwash in pure concentration on the Streptococcus mutans was (17 mm) and on the lactobacillus acidophilus 24 mm was obtained. In Fuchs mouthwash was zero and it represented effectiveness of fluoride on bacteria and ineffectiveness of Fuchs.Conclusion: The fluoride mouthrinse in different concentrations, because of having a good inhibitory effect in both methods on Streptococcus mutans and Lactobacillus acidophilus was more effective compared with that of Fuchs mouthrinse.