Journal of Dental Medicine

Evaluation of the theoretical and clinical methods for reducing marginal leakage in resin-based composite restorative materials: A review

Tabassom Hooshmand

Resin-based composite restorative materials have a substantial share in dental treatments. Their esthetic has made them patients’ first choice as restorative materials. Marginal leakage is one of their problems which leads to recurrent caries and post-operative hypersensitivity. Our aim was to evaluate the theoretical and clinical methods that have been proposed in the dental literature. Around 50 articles from Pubmed, SCOPUS and google scholar were selected and categorized in 4 groups based on the selected keywords. All the studies discussed in this paper have emphasized that there is no way to eliminate the microleakage but it can be reduced by means of some approaches. On the other hand, due to the multifactorial nature and difference of oral environment and laboratory conditions, there isn’t any certain way to define precisely. It seems that there is an absolute need for more research in this field to make the relation of theoretical results and clinical findings possible.

Evaluation of dental complaints in Tehran Medical Council between 2005-2012

Sima Rasouli

Background and Aims: One of the major challenges in dental practice is dental complaints that majority of complaints resulted in criminal prosecution and the legal practitioners. The aim of this study was to investigate the patients’ complaints on the diagnosis and treatment plan, dentist’s behavior, treatment charge, and management unlike the behavior of medical affairs, lack of enforcement in Tehran Medical Council between 2005-2011.

Materials and Methods: We referred to the Medical Council in order to obtain permission for evaluating complaints of dentists in Tehran. All files in units of prosecutors, magistrates and judicial committee were evaluated. Data were analyzed using spss version16 software.

Results: The results showed that the highest percentage of complaints was related to the how treatment was managed (41.7%) and the lowest percentage of complaints were about the dentist's diagnosis and treatment plan (2.9%).

Conclusion: Based on the results of this study, with dentists’ awareness of the existing rules and strict supervision, occurrence of complaints on the dental treatment can be prevented.

Team based learning: An innovative teaching method in preclinic course of restorative dentistry and its impact on the students’ clinical skills, Mashhad dental school

Sanaz Kargozar

Background and Aims: Implementation of innovative methods for promoting learning persistence is of high importance. The aim of this study was to introduce an innovative teaching method in preclinical course of restorative dentistry and to investigate its impact on the students’ clinical skills.

Materials and Methods: In our study, which was done at the dental School of Mashhad University of Medical Sciences, the Team Based Learning (TBL) technique was applied. 48 fourth-year students took part in the course optionally. They were divided into four groups and the stages of TBL were performed. At the end of the course, a questionnaire was administered to the students. After passing the clinical course of restorative dentistry, the mean scores of students who had passed the voluntary preclinical course were compared with those of who did not pass this course. Data was analyzed using T-test.

Results: The results of this study revealed that the mean scores of students who had passed the voluntary preclinical course was higher than that of the students who did not pass the voluntary preclinical course (P=0.02). Moreover, the questionnaire showed that 97% of students were satisfied with this course and believed that it was useful for them.

Conclusion: This study showed that the innovative method of Team Based Learning (TBL) could promoted learning along with students’ satisfaction of dental preclinical courses.

Primary school health teachers’ knowledge regarding the emergency treatment of avulsed permanent teeth in Hamadan

Amene Taghdisi Kashani

Background and Aims: Trauma to the teeth is a common problem that occurs in children. Avulsion is the one of the most complex dental damages that if be untreated can cause multiple problems. Since many of dental traumas happen in school and school health teachers have main role in children treatments, the aim of this study was to evaluate the primary school health teachers’ knowledge regarding the emergency treatment of avulsed permanent teeth.

Materials and Methods: In this cross-sectional study, after consultation training of education, all of the health teachers of elementary schools in Hamadan were selected through census sampling method and were given the regulation questionnaire. After completing the questionnaire, information was collected using software SPSS19. The data was analyzed using Fisher Exact, Kolmogrov Smirnov test, Chi-square, One way, Levenes test and
T-test.

Results: 81 Health teachers were studied and the ratio of knowledge score of all of health teachers to a maximum knowledge score was obtained to be 43/1%. There was no significant relationship between the school health teacher knowledge and their work experiences and age (P=0.23-0.6), respectively. Average of knowledge score of who were educated was more than who were not educated previously (P<0.001).

Conclusion: Primary school health teachers' knowledge of dealing with Avulsion was not at a high level. Therefore, training on the dental trauma cases is quite essential for them.

Investigation of musculoskeletal disorders and its related factors in dentists by REBA method among dental clinics faculties in Tehran in 2014

Sara Koosha

Background and Aims: Constant dynamic and static activities are considered as the main cause of musculoskeletal problems among dentists. The aim of this study was to evaluate the musculoskeletal problems and related factors among dentists in specialized clinics and dental schools in Tehran in 2014 using the REBA method.

Materials and Methods: In this cross-sectional study, the dentists from clinics of dental schools in Tehran were selected as individual targets. Nordic anddemopghrphic questionnaire were completed through interview from dentists. In order to assess the musculoskeletal disorders, REBA method (Rapid Entire Body Assessment) was used. In this method, positions and postures of the dentists during their work was observed and recorded. Data was analyzed using Regression Logestic test.

Results: The obtained results showed that among 100 dentist, 6% were in the very high risk (15-11) for musculoskeletal problems and 17% and 25% were in high-risk (10-8) and average risk (7-4), respectively. Based on the findings from Nordic questionnaire, the most skeletal- muscle travail were related to the neck (60%), lumbar (58%) and rear (46%) consequently. It seemed that factors such as gender, body mass index (BMI), height, specialty, body posture during the work (standing or sitting), smoking and using the direct or indirect vision, had an impact on the musculoskeletal disorders.

Conclusion: Findings from the final scoring of REBA showed that a high percentage of dentists were struggling with skeletal- muscle problems and they were in moderate to high range of risk for these type of disorders.

Oral health status in 5-18 years old children and adolescent with type 1 diabetes compared with healthy group in Hamadan, Iran 2013-2014

Rezvan Rafatjou

Background and Aims: Type 1 diabetes mellitus, is the most common metabolic disorders in children and adolescents. The aim of this study was to assess the state of oral health in children with type 1 diabetes compared with healthy children in 2013-2014 in Hamadan province, Iran.

Materials and Methods: The specimens were selected through convenience sampling in two groups. Group one consisted of 80 individuals (5-18 years old; case group), suffering from type 1 diabetes mellitus referred to the Pediatric endocrine clinic. Control group consisted of 80 non-diabetic healthy children who were out- patients of pediatric and orthodontic department of Hamadan dental school. Two groups were similar in age and sex. The data were collected through a questionnaire, medical records and clinical examination. DMFT, dmft, GI and PI indices were assessed in each patient. Data were analyzed using ANOVA and T-test.

Results: In spite of similarity in oral hygiene habits in both group, there was no significant difference in mean DMFT and permanent decayed teeth in both groups (P>0.05), but the mean dmft (P<0.008) and primary decayed teeth (P<0.011) in the control group was significantly higher than that of the case group. Also, diabetic patients had significantly more gingival inflammation (P<0.05). The mean PI in the two groups did not differ significantly. Oral hygiene habits were similar in both groups but diabetic patients were significantly referred to dentists with lower frequency then that of control group (P=0.00).

Conclusion: The devastating effects of diabetes on the oral health, along with other side effects can be effective in promoting tooth decay and gingivitis in diabetic patients. Unfortunately, oral health care and programmed dental visit were not the priority for the diabetic patient (and parents) involved in our study. Therefore, programs to increase awareness and encourage patients for a better control of their oral health in order to diminish diabetes' devastating effects is recommended.

Effect of soy and bovine milks on the dental plaque pH

Sara Zahedi Rad

Background and Aims: Soy milk in competition with other drinks introduced as healthy and nutrient drink. Nowadays, most important tendency to consume soy milk is new extended developments to produce soy milk with more acceptable taste and is believed that soy milk is a good substitute for bovine milk in lactose-intolerant people. Cariogenic potential of bovine and soy milk is a subject for lots of researches in the last decade. The aim of this study was to evaluate the effect of soy and bovine milks on the pH changes of dental plaque.

Materials and Methods: In this study, 10 healthy dental students in age range of 25-35 were selected after written consent upon study entrance criteria's such as, amount of saliva streptococcus mutans, amount of lactobacillus, salivary secretion rate, buffering capacity of saliva, absence of active dental caries, absence of systemic disease and etc. Dental plaque pH in the interproximal areas of 2nd premolar and 1st molar in all 4 quadrants was taken by Metrohm micro electrode and digital pH meter before (0) and at 2, 5, 7, 10, 15, 20, 30, 40, 50 and 60 min after taking with 3 tested materials (soy milk, plain milk 1.5% and 10% sucrose solution as a positive control). Then pH curves were drawn according to the time of each test product. In this study, using pH=6 was considered as critical pH. Maximum pH drop and ∆pH after taking 3 tested materials were analysed Repeated measure ANOVA (P<0.05).

Results: According to the test materials, the lowest pH was after rinsing with 10% sucrose solution following soy milk and in the last was 1.5% bovine milk. All the test materials showed significant differences among each others
(P<0.05).

Conclusion: Bovine milk in none of frequent timing dropped its pH below basic pH but also significantly increased the plaque pH above the critical pH. The maximum pH drop for soy milk was in 2minutes after consumption but it never reached below the critical pH.

Effect of sodium bicarbonate against Candida albicans in denture stomatitis: An in vitro study

Behzad Salari

Background and Aims: The aim of this study was to investigate the effects of sodium bicarbonate against candida albicans, the main infectious factor of denture stomatitis, and to compare it with other common anti-candida medications.

Materials and Methods: Three concentrations of Candida albicans (105, 106, 107 CFU/mL) were prepared. Experimental substances were 5% sodium bicarbonate, nystatin, chlorhexidine, and sterile saline (as control). Each of them was added separately to the same amounts of Candida albicans of different concentrations, and sampled at the intervals of 1, 2, 3 and 4 min. Then, the samples were cultured and incubated. The number of formed colonies was counted for each plate. The data were analyzed, using ANOVA and Tukey test.

Results: Sodium bicarbonate showed a noticeable anti-candida effect on the concentrations of 105 and 106 CFU/mL, with almost similar anti-candida effect as nystatin and chlorehexidine(P=0.29, P=0.32). Nystatin was the most effective medication on the concentration of 107 CFU/mL of candida (P=0.03, P=0.01). Sodium bicarbonate and chlorhexidine were less effective in this concentration with no statistically significant difference (P=1.00).

Conclusion: Sodium bicarbonate showed a significant anti-candida effect at low and medium concentrations of Candida albicans, but nystatin was more effective in the higher concentrations.

Interaction of Er,Cr:YSGG laser with dental hard tissue

Abbas Majdabadi

Background and Aims: Nowadays lasers are used as alternatives to the tooth preparation because of reducing pain, bloodshed and stress. The aim of this study was to observe the effect of Er,Cr:YSGG laser on the dental hard tissues.

Materials and Methods: For this studty, molar teeth with no caries or dental restoration and enamel cracks were used. The laser power were taken from 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 up to 6 Watts for enamel and 0.5, 1, 1.5, 2, 2.5, 3, 3.5 and 4 Watts for dentine simultaneously with water spray. The ablation effect was observed on both enamel and dentine. Finally, by use of a CCD camera connected to the computer, the dimensions of ablated areas were measured and results were applied in graphs.

Results: Volume of ablation was increased by increasing laser power. Also, by increasing energy value in each stage, the depth of ablation was increased for enamel and dentine. SEM images of ablations by 3.5 and 4 Watts on enamel and 1 and 1.5 Watts on dentine did not show any sharp edges.

Conclusion: The ablation volumes and depth increased by increasing the energy of laser pulses power. The reason for this trend was due to the water spray while irradiating and good absorption of water by laser beam.

A comparative evaluation of implant supported zirconia framework gap of two CAD/CAM systems

Marzieh Alikhasi

Background and Aims: Marginal accuracy is a crucial factor influencing the clinical long-term reliability of implant-supported fixed dental prostheses (FDPs). The aim of this in vitro study was to evaluate the marginal fit of three-unit zirconia bridge frameworks fabricated using two different computer-aided design (CAD)/
computer-aided manufacturing (CAM) systems (AmannGirrbach and Zirkonzahn).

Materials and Methods: The master model of 3-unit FDP was made of two implant abutments (AmannGirrbach and Zirkonzahn) from canine to second premolar. Twelve frameworks were manufactured using each fabricating system from semi-sintered zirconia blanks, which had to be sintered for final density after milling. After manufacturing, the absolute marginal discrepancy in each abutment were determined by means of Video Measurement System (VMS). The data were analyzed, using independent and paired t test (P=0.05).

Results: For the premolar abutment, the absolute marginal discrepancy of frameworks fabricated by AmannGirrbach system was significantly greater than those of the other system (P=0.005). There was no significant difference between the marginal discrepancy of canine and premolar abutments (P>0.05).

Conclusion: Within the limitations of this study, it could be concluded that the marginal fit of zirconia FDPs was significantly dependent on the CAD/CAM system used, but the abutment size was not an effective factor.