Journal of Research in Dental Sciences
Year:2018 | Volume:15 | Issue:2 (56) |Papers Count:10

Background and Aim: Although it is shown that chlorhexidine can have a positive effect on periodontal indices, the resulting stains, prevent it to be prescribed for long term use. Therefore, we studied the effect of low concentration chlorhexidine on the periodontal indices and the level of staining in orthodontic patients.Materials and Methods: This study was conducted in a single blind randomized clinical trial with 20 patients (aged 14-30) undergoing fixed orthodontic treatment. Subjects were divided into two groups of 10, with group 1 on the Orthokin 0.06% chx mouthwash, and group 2 on the Orthokin 0.08% chx mouthwash.This three month study was divided into two phases.In each session, PI, GBI, GI and SI indices were measured. The cross over between the groups took place after 3 weeks wash out. Statistical analysis was then performed on the data collected.Results: A significant decrease in both GI and GBI compared to baseline was observed in both phases. In case of PI, in phase I, a significant decrease compared to baseline was observed in both groups. In case of SI, In phase II, both products showed a significant increase in staining.Conclusion: The results of this study suggest that Orthokin oral health products with low concentration of chlorhexidine play an important role in reducing PI, GI and GBI indicators in patients undergoing fixed orthodontic treatment.However, further studies with larger patient populations are required to understand the effect of such products on teeth staining.

Background & Aim: Injection is common in almost all patients. Considering the limited study in this field, this research was conducted for comparison of articaine and lidocaine on pain during inferior alveolar nerve block on patients referred to the facial and maxillofacial surgery department of Islamic Azad University dentistry in Tehran, 2017.Material & Methods: A randomized, single blind split-blind clinical trial was conducted. All patients requiring double-sided jaw injection were studied. Each side of the jaw was randomly assigned to control (lidocaine 2%) and case (Articaine 4%). An injection was performed for each person and the pain level during injection was measured with a 10-point VAS scale, in which zero means as no pain and ten as most pain, with a patient questionnaire. Then, in the next week, injection was performed on the other side of the jaw and the pain was recorded through the above. The solutions used were lidocaine 2% with epinephrine 1.80000, manufactured by the Pharmaceutical Company and Articaine 4% with epinephrine 1.100000, made of septodent factory in France. The needle used was 27-gauge long-shaft manufactured by the NRK factory in Iran. Each cartridge was injected during 60 seconds and was performed by one person on both sides of the anesthetic. Finally the results were evaluated by MANN_U_WHITNEY test.Results: This study were conducted on 20 subjects (40 specimens) with lidocaine (1.9±0.85) and articaine (1.1±0.71), respectively. The pain was 0.8 scale or 42% lower than that of lidocaine. (p<0.05).Conclusion: Articaine seems to have less pain during inferior alveolar nerve block.

Background & Aim: oral hygiene instruction is usually done by hygienist mentors at schools via artificial models. Today, use of animation films is considered. The goal of this research was to compare new method with the traditional method to assess knowledge among students at the last elementary class in one of the schools in Tehran.Materials & Methods: a multiple choice questionnaire with 6 questions was given to the students and the score was recorded as “pre-test” score. Then the students were randomly divided to the control and test groups (learning by educational film or artificial models). After 3 weeks of teaching, the questionnaire was answered again by the students and the score was recorded as “post-test” score. Mcnemar and Chi-squared statistical analysis were used to interpret the results.Results: Knowledge before learning in the artificial models & animation film was 48.2% and 33.3% respectively and after learning these percentage changed to 64.3% & 59.7%.Both learning methods showed positive result to promote knowledge (P<0.01), although there was no significant difference between these two methods (P<0.6).Conclusion: the two learning methods showed the same improved knowledge among the test groups. It could be suggested the animation film could be assumed as a good method due to its repeatability and cost effective advantage.

Background & Aim:: One of the problems in removable dentures is gradual color changes of the teeth. Which could results in patient dissatisfaction. This study designed to investigate the effect of without alcohol listerin mouth wash (Johnson & Johnson) on two types of composite resin teeth (YAMMAHACHI & APPLE).Material & Method: This experimental in-vitro study has been done on upper central incisor: 15 samples of artificial tooth APPLE (Ideal Makoo -Iran: A1, 17) and 15 samples of artificial tooth (yammahachi: A1, S8).Color measurements of teeth were performed by using spectrophotometer and recorded before immersion. Color change values were determined after 14 and 28 days. Color differences were characterized using the CIE lab color space. Statistical analysis was performed with T-Test for each dental group and eventually the PAIRED T-TEST was used for comparing the results of two groups.Results: This study performed on 30 spicies. color changes for YAMAHACHI and APPLE were equal to 1.60±0.83and 1.65 ±0.96 respectively (p<09) after 14days follow up -, color changes for YAMAHACHI and APPLE were equal to 1.99±0.86 and 2.32±0.94, respectively. (p<0.4) after 28 days follow up -color changes for YAMAHACHI was equal to 0.59±0.38 Between 14-28 follow up days -color changes for APPLE was equal to 1.00±0.47 (p<0.005) Between 14-28 follow up days Conclusion: It seems by time passes, color change of Apple artificial tooth is more than Yamahachi artificial tooth.

Background & Aim: One of the most regular extrinsic factors that decreases microhardness of the enamel is acidic beverages such as energy drinks. These beverages reduce the pH of the oral environment and could solve dental enamel. This in vitro study demonstrates the effect of CPP-ACPF paste on enamel microhardness, demineralized by energy drinks.Materials & Methods: In this experimental study, 30 intact enamel pieces of human premolars were selected and primary microhardness was measured and recorded on all samples by Microhardness Tester (Vickers). Then divided into three groups. Control group was immersed in 30 ml Red Bull drink and artificial saliva. This procedure was for 7 days. Group 2 were immersed in Red Bull drink like group1, but samples were coated with 0.3 gr CPP-ACPF for 3 minutes after immersing in energy drink. Then the paste was mixed with artificial saliva for 2 minutes. In group 3, first, CPP-ACPF was applied similar group 2, then after one hour, the samples were immersed in Red Bull drink as mentioned before. At the end of 7 days, the secondary microhardness was measured. The data were analyzed with repeated-measure ANOVA and Post Hoc analysis.Results: The microhardness was significantly different before and after the interventions in each group (P<0.001). Groups 2 (secondary microhardness: 316) and 3 (secondary microhardness: 318) were significantly different from group 1 (secondary microhardness: 277.2). (P<0.001) But, there was no significant difference between groups 2 and 3 (P=0.326). It shows that application of the CPP-ACPF before or after energy drink can increase microhardness of samples or remineralization of them comparing to group1.Conclusions: According to this study, Red Bull energy drink decreases enamel hardness. Using CPP-ACPF paste before or after drinking energy beverages could increase the hardness and improve remineralization.

Background & Aim: Extrusion of debris from apex is one of the main factors of flare up (inflammation, pain or combination of both). Various studies have been conducted toward the amount of debris extrusion but no one compared this drawback on one – shape and xp-shaper system in curved root canals. So, this study aimed to determine the amount of apical debris extrusion following preparation of canal by one-shape or xp-shaper in curved canals of mesiobuccal root in mandibular first molars.Material & Method: This experimental study was done on 34 mandibular first molars with 30 to 40 degree curved mesiobuccal root canal. The samples were randomly divided in two groups. First group had one –shape for root canal preparation while the other had xp-shaper. Roots of the teeth were fixed in pre weighted fluxes till cervical area so that all apical debris were collected in vials. After desiccation process, the vials were weighted again. The difference between original and secondary weight of vials containing debris is considered as weight of debris extrusion. Data were analyzed using T-test.Results: Amount of debris extrusion in one– shape group was 0.018±0.014 and in xp-shaper group was 0.01±0.007 and the difference was statistically significant (0.01).Conclusion: Considering the situation and limitation of this in vitro study, xp-shaper rotary system was associated with less debris extrusion compared to one – shape systems.

Background & Aim: Several factors are affect retention of post and core. One of the most common problem is time of core preparation after post cementation. The purpose of this in vitro study was evaluate the influence of timing of coronal preparation on the tensile strength of cast post and cores cemented.Methods & Materials: In this in vitro study 30 extracted intact human premolars were selected. Each tooth was sectioned 16 mm from the root apex. After endodontic treatment of teeth the root canals were prepared for post fabrication. post and cores were cast in Ni-Cr alloy and cemented with zinc phosphate cement then divided into 3 groups: 1) core preparation immediately after cementation 2) core preparation 24 hours after cementation 3) control (without preparation).The tensile strength test was performed by a universal testing machine (zwick roell) with speed of 0.5 mm/min .The obtained data statically analyzed using one-way ANOVA test.Results: Significant differences were found in tensile strength between 3 groups. Tensile strength were\, 176.83±43.15 for group1, 120.06±24.27 for group2 and 186.76±44.61 for group3. There is no significant difference between groups 1 and 2. (p=1.000) Conclusion: It concluded that core preparation immediately after setting and cementation with zinc phosphate has significant influence the tensile strength of post and cores but core preparation 24 hours after setting has not significant effect on the tensile strength of post and cores.

Background & aim: Hypomineralization of the molar incisor (MIH) is a malformation with a systemic background whose etiology is not well defined. One of the factors contributing to the development of this lesion is the likelihood of its association with respiratory problems and asthma in the first years of life. The purpose of this study was to investigate the association between MIH and asthma.Material & Methods: 73 six to twelve years old children with asthma and the control group in Rasht. Dental examinations were carried out by a practitioner at the site of asthma clinic and schools, with the use of mirrors and syringes without drying the dental surfaces. Chi-square test, Fisher' s exact test, Independent t-test, Mann-Whitney test and Multivariate Regression Logistic were used to analyze the relationship between different factors.Results: 29.3% of asthmatic children had MIH, while only 17.1% of the control group had it. P<0.001 The Mean DMFS index was 0.87±0.34 and 0.87±0.32 in asthmotics and controls respecting (p<0.9).Conclusion: Based on the results of this study, children who had symptoms of asthma before the age of three have a high risk of having MIH and should be gone under early dental care.

Background & aim: canal and root morphology in an Iranian population using cone beam computed tomography (CBCT) scans since higher knowledge about the root canal system often leads tohighersuccess rate of endodontic treatment.Material & Methods: This descriptive study was performed on 200 CBCT scans of the mandibul of patients with sound bilateral mandibullarycannines. The level of symmetry of the roots and canals was determined.The frequency of anatomical features of the root canals was compared between males and females using the T-test.Results: In both males and females, the level of symmetry was higher in teeth with one root, onecanal, one orifice and one foramina.One root and one –canal teeth bilateraly had a higher frequency in males than in females.Vertucci's canal types I and III showed the highest level of symmetry in both males and females.Conclusion: Considering the symmetry rate over 80% in all anatomical features of the mandibullarycannines (Root=94.8, canal=89.3, type of canal=88, orifice=99.44, toramine=94.8) referral to an endodontist seems necessary when general dentists cannot accomplish the root canal treatment of mandibullary canine at one side.

Background & aim: Electronic Information Resources are very important for medical researchers. Suitable substrates for use in the field of digital libraries to provide electronic information resources. Thus, the objective of this study is to determine awareness, use and Satisfaction of dental assistants of Iranian Medical Digital Library.Material & Methods: This is a descriptive and cross sectional study conducted among 267 dental assistants at Tehran, Shahid Beheshti and Shahed Universities of Medical Sciences used census to recruit participants used a self-designed questionnaire to collect data. Validity of the study instrument was investigated by faculty members in Medical Information Sciences and its reliability was assessed by Cronbach's alpha of.88.Results: 80 percent of dental assistants were aware of Iranian Medical Digital Library. A majority of respondents used its from home and the library of college. Most of them used Iranian Medical Digital Library for their research work. The largest number of them studied 1-2 resources per week. The level of satisfaction was moderate.Conclusion: Iranian Medical Digital Library is as a Known gateway between dental assistants. Thus, planning is necessary for awareness and use of Iranian Medical Digital Library.