JOURNAL OF RESEARCH IN DENTAL SCIENCES
Year:2018 | Volume:15 | Issue:3 (57) |Papers Count:11

Background & Aim: Wear of acrylic teeth after passing years is still one of the main problems in dentistry that may lead to loss of chewing function, decrease of facial vertical height and unpleasant smile.This study aimed to evaluate the comparison of wear resistance of President & Ivoclar teeth against natural teeth.Materials & Methods: In this Experimental Study, 64 samples of second premolar teeth that included 24 upper & lower second premolar of President teeth and 24 upper & lower second premolar of Ivoclar teeth and 16 upper & lower natural teeth, were included. The samples divided into 6 groups (5 case and 1 control), Each of 5 case groups included 12 samples, and the control group included 4 samples. After that, 3D images of each samples were provided by lab 3D scanner and then all of the samples (case and control) were put in the incubator (37°c) for 24h.After that, they were put in thermo cycler After these processes, samples were scanned for the second time. Finally, 3D scans were superimposed. In the comparison of difference between samples volume, Repeated Measure ANOVA Test, was used.Results: after wear procedure with chewing stimulator, control group (natural teeth) had less wear vs president and ivoclar teeth, significantly CP<0.05). But President& Ivoclar teeth had not significant difference when they against each other (p>0.05). President & Ivoclar teeth when against to the natural teeth had more wear vs when they put against each other (p<0.05).Conclusions: It seems, wear of artificial teeth was more when they put against natural teeth. But there was not different between president and Ivoclar teeth.

Background and Aim: This study was conducted to determine the effects of the injection rate in infiltration technique on pain, anxiety and vital signs of the patients using ICT injection device amongst the patients referring to the periodontics and oral and maxillofacial department of Azad University of Tehran in 2016.Materials and Methods: The method of the current study was randomized single blind-split mouth clinical trial.30 patients need to be injected bilaterally on maxilla in two treatment sessions. Next, each sample was selected randomly to be injected at two paces (25 seconds or 120 seconds) Then the pain measurements were performed in Visual analogue scale (VAS), and vital signs (breathing patterns and heart rate) before, right after and 5 minutes after the injection with anxiety measurements (FAS) and digital sets of Buerer BM60 by a person unaware of the groupings. After data collection, Kolmogorov-Smirnov and t-squared tests were used to analyze the data.Results: The pain levels were significantly different between the pace of 120 s and 25 s (p=0.0006) as the lower pace resulted in less pain comparing to faster injections.The hypotension was significantly different as well in 120 s and 25 s (p=0.029) Injection with slow velocity resulted in a change in the lower systolic pressure immediately after injection (128.87±14.36) compared with the time before injection for the patient (130.53±13.38), compared to rapid injection immediately after injection (124.97±14.09) compared to the time before injection for the patient (128.00±10.92).There were no significant differences in other variables (p=0.1) Conclusion: In slower injection rate the pain is less than faster injection. Also slow-injection, as compared to rapid-injection, cause to less changes in systolic blood pressure immediately after injection. The injection rate did not affect the patient's heart rate, diastolic pressure, and anxiety.

Background & Aim: Removal of salivary gland after surgical intervention can affect oral health by affecting saliva. This prospective study evaluates the effect of one-side parotid removal on salivary flow and oral health indexes, including CPITN and DMFT.Material & Methods: 15 of the patients referred to Omid and Imam Reza Hospital in Mashhad were selected by indicating one of the parotid salivary glands resection that did not require post-operative radiotherapy. These patients were evaluated for CPITN and DMFT in both half of the mouth and the amount of unstimulated saliva.Then these patients were underwent surgery and one year after surgery, these indices were measured again in patients. The results were analyzed by Wilcoxon test.Results: Seven patients were excluded from the study due to non-attendance in follow-up period. This study showed that the overall CPITN of patients before surgery was 4.28±2.75 and after surgery 5.50±4.75, (P=0.19) the mean DMFT of patients before surgery was 14.28±3.86 and the mean after surgery was 15.42±3.59. (P=0.02) The results of this study showed that resection of parotid gland had significant effect on dental caries (p=0.034) and salivary volume (p=0.037), but this did not have a significant effect on periodontal parameters.Conclusion: This study showed that the unilateral removal of parotid gland significantly increased the patient's DMFT level and reduced the salivary release.

Background & Aim: Evidence-based dentistry (EBD) is a new approach to maintain the healthcare and oral hygiene, which requires proper integration of evidence, diagnosis and clinical skills of a dentist, as well as patient's medical needs and priorities. The aim of this research was to evaluate the outcomes of education on knowledge, attitude, access and confidence of dental students in field of EBD and its continuity.Materials & Methods: Sampling was based on census method and conducted on 250 students In this cross-sectional study, a questionnaire with 4 different sections including knowledge, attitude, access and confidence was surveyed 310 dental students educating in the 5th, 7th, 9th and 11th semesters. After collecting data, statistical analyses were performed using Kruskal-Wallis test. Related factors including age, gender and grade were also analyzed.Results: The score of knowledge was 2.17±1.7 out of the maximum score of 10, (poor knowledge) the attitude score was 32±4.3 out of the maximum score of 50, (moderate attitude) the access score was 24.9±5 out of the maximum score of 45 and the confidence score was 15.3±4.2 out of the maximum score of 30. (moderate access and confidence) The Knowledge of students increased significantly (P<0.005); however, it had no influence on attitude, access and confidence (P<0.2). The mean score of access and confidence among male students was significantly higher than female students. (p=0.003) Conclusion: The evaluated students had poor knowledge on EBD but their access confidence were moderate. Education of course had no remarkable impression on these factors. And it is better to schedule change in presentation, content, more fallow up and its practical management in clinical curses. So, this issue represented the necessity of more attention to study of EBD and their performance, in dental faculty, Islamic Azad University.

Background & Aim: Mechanical, intermittent and precise microbial plaque is one of the main stages of chronic periodontal disease treatment. Due to the increasing use of herbal toothpaste, this study was conducted to compare the effects of Crest 7 Complete with Silca herbal toothpaste.Material & Method: In this cross-over clinical trial study, 60 dental students (14 males and 46 females) with a mean age of 25.38.8±1.588 were selected. The plaque index was recorded, scaling and prophylaxis was done. The toothpastes (Silca and Colgate) were randomly assigned to individuals. After 14 days, the plaque index was registered. Scaling and prophylaxis were performed again and the second toothpaste was given. Changes in plaque index were analyzed by Mann-U-Whitney and Wilcoxon tests.Results: Plaque index for the Crest was 0.91±0.23 and for the Silca was 0.85±0.20 and the difference was not statistically significant (p<0.4).The changes in dental plaque for the Crest toothpaste was 0.81 and for the Silca toothpaste was 0.76, the changes were not statistically significant (p<0.4). Within each group, Crest and Silca toothpaste reduced dental plaque respectively from 1.67 to 0.91 (48.5 percent) and from 1.65 to 0.85 (51.5%) that the changes were statistically significant ( p<0.02).Conclusion: Silca herbal toothpaste similar to the Complete crest 7 is effective in controlling dental plaque.

Background & Aim: Pain control in mandible surgery has become a challenge for physicians; the effects of using modern methods, such as pre-drugs with oral medicines before surgery, are still in contraversy. Therefore, the aim of this study was to investigate the effects of preglaboline on management of postoperative pain of fracture of the mandible.Material & Method: In this clinical trial study, after ethical agreement pain management between groups who recived drug (30 patients) and did not receive drug (30 patients) was compared. After random sampling, the intervention group consumed one preglabolin capsule 300 milligrams with 50 ml of water half an hour before surgery. The severity of pain was measured and recorded in both groups during the first eight hours after surgery. Mann-U-Whitney was used to statistical analyzing.Results: Pain severity decreased in both groups over time, but pain was significantly different between two groups (P=0.001), & hours after surgery, pain severity was 1.76±0.93 and 2.96±1.21 in sample and control groups (P=0.01).Conclusion: Positive effects of pregabalin premedication on better management of pain after Mandibule surgery were observed in this study.

Background & Aim: One of the induced major problem after bleaching treatments is enamel surface roughness increase, which can lead to increased risk of dental caries, plaque accumulation and later enamel discoloration. In this study the effect of adding CPP-ACP to home bleaching gel on enamel roughness was evaluated.Methods & Materials: in this experimental study, premolar teeth have been used. The samples divided in three groups (n=13) randomly. The roughness of each group was evaluated before the bleaching process with Atomic Force Microscopy. Samples was kept in Carbamide peroxide 20%, CP 20% and CPP-ACP (with 1: 1 ratio), CP 20% and CPP-ACP (with 1: 2 ratio) for 14 days, each day 4 hours. The roughness was evaluated two times after bleaching and the results were evaluated statistically. The gained data in each group were evaluated by PAIRED T-Test, and for intra-group analysis ANOVA and POST HOC test was used.Results: Surface enamel roughness before bleaching was same in all three groups. (p<0.4) The surface roughness after bleaching was increased in Carbamide peroxide 20% and decreased in group 1, significantly The increase was significant in first group (p=0.01), the decrease was not significant in second group, but significant in third group. (p=0.01) Conclusion: The 20% CP and CPP-ACP with 1: 2 ratio can significantly decrease the surface roughness in comparison to the primary roughness.

Background & aim: There is evidence that thyroid disease, especially hypothyroidism, is associated with oral lichen planus based on immunologic pathogenesis. The aim of this study was to evaluate the prevalence of oral lichen planus and related factors in thyroid patients referred to Endocrinology and Metabolism Research Institute of Iran University.Material & Methods: In this cross-sectional study, 1200 individuals with a definitive diagnosis of thyroid disease were surveyed. In case of observation, oral licorice was recorded in the form of information. The data were analyzed by chi-square test.Results: Of these, (5.3%) of patients had oral lichen planus, with a frequency of reticular type of 47.6%, a type of papule 22.2%, a type of plaque type 17.5% and an atrophic, erosive and atrophic type % They were. Levothyroxine consumption had significant correlation with occurrence of lichen planus. (p<0.005). Females with hypothyroidism with age average of 57 years old and history of smoking more had lichen planus significantly (p<0.05) Conclusion: The incidence of lichen planus in patients with thyroid disease in this study was slightly higher than normal population.

Background & aim: Angiogenesis has a significant role in growth and development, progression and behavior of malignant tumors. Since SCC is the most common carcinoma of oral cavity, determination of angiogenesis role in behavior of this malignancy is of great importance. The purpose of this study was to evaluate the relationship between MVD and demographic factors such as age, gender and location and histopathologic grade of the tumor.Material & Methods: In this descriptive-analytic study, 22 paraffin embedded blocks of SCC of head and neck region. From oral & Maxillofacial pathology dept., Dental faculty, Qazvin University. H & E stained slides of related patients were selected and the specimens were graded by pathologist according to Broder’s classification. The blocks were then stained with anti CD34 monoclonal antibody by means of immunohistochemistry method. In each specimen, three highly stained fields were selected and then MVD average of those fields were counted and analyzed. Analysis of variance (ANOVA) and T-Student analysis were then used to measure the variables with p<0.05 as level of significance.Results: MVD was 32.66±7.4 and 43.2±7.1 in well and moderate-poor diff SCC samples (p=0.003) These was no significant correlation between demographic factors and MVD (P>0.05).Conclusion: According to this study, there was a reverse relation between degree of differentiation of SCC and angiogenesis. Hence it seems in low grade tumors-in addition to better cell differentiation-less angiogenesis similarly plays role in prognosis of these lesions.

Background & aim: Tooth decay is one of the most common problems in dentistry in this period. Therefore, considering the importance of this issue on public health, this study aims to provide a systematic review and meta-analytic study of the importance of dental caries in deciduous and permanent teeth in children, during 1 to 15 year age range.Material & Methods: A meta-analysis was performed for relevant articles in scientific databases including, Medline (PubMed) و Science Direct و Google scholar and SID (March 1997 to February 2016). Heterogeneity of study was checked usingI^2 index. Data were analyzed using the Comprehensive Meta-analysis (CMA) software.Results: In the 22 papers submitted to the meta-analysis process, which included 13 articles of dental caries in deciduous teeth's and 9 articles of permanent teeth decay, 29225 individuals aged 1 to 15 years included group of deciduous teeth's 6118 individuals In the age range of 1 to 7 years, and the group of permanent teeth, 23107 individuals aged 8 to 15 years, the overall prevalence of dental caries in deciduous teeth (dmf) was 62.8% (Cl 95%: 52.2-72.4%) and the overall prevalence of caries in permanent teeth (DMF) of Iranian children was 78.6% (Cl 95%: 73-83.2%).Conclusion: According to the results of this study, the prevalence of dental caries in deciduous and permanent teeth was high in Iranian children and therefore provision of training to increase parental awareness and affordable and available dentistry services is essential for growth.