Journal of Dental Medicine
Year:2010 | Volume:23 | Issue:3 (64)|Papers Count:8

Background and Aims: Marginal adaptation is important for the long-term success of full-coverage restorations. Preparation design is one of the important factors influencing the marginal integrity. Therefore, the purpose of this study was to compare the effect of radial shoulder and chamfer finish line designs on the marginal adaptation of all-ceramic Cercon restorations.Materials and Methods: This in vitro study was done using single blind experimental technique. One stainless steel die with 7 mm height and 5 mm diameter was prepared by milling machine. The preparation design consisted of half radial shoulder with 1mm depth and half chamfer with 0.8mm depth. All walls had a convergence angle of 10º. Ten stone dies and ten ZrO2 copings of Cercon (Cercon Smart Ceramics, DeguDent, Hanau, Germany) were made and after cementation were ground at buccolingual direction. Then marginal gap of each sample was measured by scanning electron microscopy. Data were then analyzed using t-test.Results: The mean marginal gap for radial shoulder was 98.4mm and for chamfer was 39.7mm. The difference was statistically significant (P=0.002).Conclusion: From the results, it may be concluded that the marginal gap of chamfer preparation is less than that of radial shoulder.

Background and Aims: Temporomandibular disorder (TMD) is a common problem in maxillofacial area, which is often diagnosed with pain, temporomandibular joint malfunction and masticatory muscles dysfunction. Teenagers and adolescents are susceptible to TMD, but no information is available regarding the prevalence of TMD in this groups. Furthermore, a few investigations have evaluated the prevalence of TMD in mixed dentition. The aim of this study was to evaluate the prevalence of TMD in mixed dentition and its association with malocclusion.Materials and Methods: In this cross-sectional study, 222 patients with the age of 6-12 years referred to Pediatric and Orthodontic departments of Tehran University Dental School were evaluated. Clinical examinations were done and questionnaires were filled out. The data were analyzed using SPSS 11.5 and logistic regression test.Results: The prevalence of TMD in mixed dentition was 14.4%, which was higher in girls compared with the boys. The most TMD prevalence in the mixed dentition was seen in 11-12 year old patients. The prevalence of joint sound, masticatory muscle tenderness, and joint pain was 23.9%, 20.9%, and 5.4%, respectively. CL III malocclusion showed higher TMD prevalence and also TMD was more common in children with 6 mm overjet and more. Unilateral posterior cross bite, deviation of mandible, and TMD were significantly related to each other.Conclusion: In the present study, temporomandibular disorder was related to malocclusion.

Background and Aims: Selecting an appropriate treatment plan is one of the most critical aspects of dental treatments. The purpose of this study was to compare multimedia system and conventional method in patients’ selecting prosthetic treatment and the time consumed.Materials and Methods: Ninety patients were randomly divided into three groups. Patients in group A, once were instructed using the conventional method of dental office and once multimedia system and time was measured in seconds from the beginning of the instruction till the patient had came to decision. The patients were asked about the satisfaction of the method used for them. In group B, patients were only instructed using the conventional method, whereas they were only exposed to soft ware in group C. The data were analyzed using Paired-T-test (in group A) and T-test and Mann-Whitney test (in groups B and C).Results: There was a significant difference between multimedia system and conventional method in group A and also between groups B and C (P<0.001). In group A and between groups B and C, patient's satisfaction about multimedia system was better. However, in comparison between groups B and C, multimedia system did not have a significant effect in treatment selection score (P=0.08).Conclusion: Using multimedia system is recommended due to its high ability in giving reliable answers to a large number of patient’s questions as well as in terms of marketing.

Background and Aims: Nowadays reconstruction of alveolar defects has become one of dentists' problems especially in areas which are going to get dental implants. Inorganic bovine bone mineral (Bio-Oss) is one of the most popular graft materials that acts as a structure for migration of osteoblasts. If migration, proliferation, and differentiation of osteoblasts can be promoted by a material, it would be possible to reconstruct more amount of bone in a shorter period of time. Milk contains vital proteins that regulate bone growth. One of these important proteins is lactoferrin. The aim of this study was to examine the effect of added bovine lactoferrin to Bio-Oss on osteogenesis.Materials and Methods: Two doses of 50 and 500 6g/ml of lactoferrin were prepared. Ten New Zealand white rabbits were selected for this study. Four 6-mm symmetrical detects were created in each rabbit's calvarium. Two of these sites were filled with Bio-Oss that was wetted with two doses of lactoferrin. Third detect was filled with Bio-Oss alone and the forth one was left empty as control group. After 4 weeks histologic and histomorphometric analysis was performed. Data were analyzed by Cochrane Q and Friedman test.Results: There was no sign of obvious inflammation in any of four groups. Also there was no difference among four groups in terms of vitality, type of new bone, and foreign body reaction. However, amount of bone formation in control group was significantly lower compared with the other 3 groups (P<0.05). Although lactoferrin containing groups showed little increase in bone formation especially in higher concentration, there was not statistically significant difference among the three test groups (P=0.1). Amount of remaining biomaterial also was lower in lactoferrin containing groups compared with the Bio-Oss group but the differences were not significant (P=0.392(.Conclusion: Although there was no significant difference among the test groups, it seems that the added lactoferrin increases bone formation. Furthermore, because of possible washout of the lactoferrin from the defects, it would be helpful to find and evaluate a proper carrier agent for lactoferrin to see its real effects.

Background and Aims: Candida species are opportunistic pathogens which live as benign commensal organisms in the oral cavities. The infants are more susceptible to opportunistic microorganism colonization. This study was designed to evaluate the presence and quantity of Candida colonies in infants’ oral cavities and its relation with age, gender, and type of diet and mothers’ education level.Materials and Methods: This historical cohort study was performed on two groups of infants; 1) infants predominantly on breastfeeding (n=45) and 2) infants on bottle feeding (n=45). Oral samples were collected with swab technique and Candida species were identified using germ-tube test. The data were analyzed by using SPSS software, chi-square, logistic regression and Mann-Whitney tests.Results: The Candida colony was seen in 53.3% of infants. The difference in oral Candida carriage and mean numbers of Candida colonies, according to the mothers’ education level, was statistically significant (P=0.0001, P=0.000, P=0.0001); however, the mentioned two groups were not significantly different in terms of the presence of Candida and non Candida species (P=0.45). Candida colonization was not statistically related to the age and sex (P=0.48, P=0.4). By logistic regression test, it was found that type of diet and mother's education level affected oral Candida colonization (P<0.05).Conclusion: The oral Candida colonization in breast-feeding infants is less than the bottle-feeding ones that might be attributed to the antifungal effects of mother's milk and the role of bottles in transferring the Candida species. Also increase in mother's education level leads to reduction in oral Candida colonization, which may be the result of improved hygiene. However, no relation was seen between oral Candida carriage and age or gender of infants.

Background and Aims: Intrabony periodontal defects are one of the important problems in periodontal diseases. Treatment of intrabony periodontal defects with synthetic materials such as Cerasorb has been shown to enhance periodontal regeneration. The aim of this study was to compare the effect of Cerasorb with autogenous bone graft (A.B.G) as a gold standard in treatment of two to three wall periodontal defects.Materials and Methods: In this interventional or randomized clinical trial study, 24 two to three wall intrabony defects were selected in a double blind manner. Defects were randomly (with tossing a coin) divided into two groups (test and control). Defects in test group were treated with flap surgery and Cerasorb. In control group, defects were treated with flap surgery and autogenous bone graft. At baseline and 3-month, 6-month and one-year follow up evaluations; clinical and radiographic assessments were performed. Data were statistically analyzed using the paired t test, Wilcoxon and Mann-whiteny. The level of significance was set at P<0.05.Results: At the 3-month, 6-month and one-year visits, the parameters of probing pocket depth (PPD), probing attachment level (PAL), bone level (distance between CEJ and alveolar crest), and bone density were not significantly different in test and control groups (P>0.05). However, in each group there was significant differences in 4 parameters before and after surgery (P<0.05).Conclusion: Treatment with Cerasorb compared to A.B.G produced the same results of improvement in two to three-wall intrabony defects. Thus, the use of Cerasorb can be suggested in treatment of intrabony periodontal defects.

Background and Aims: There is not sufficient knowledge about the relationship between smoking and vertical bone loss in periodontal diseases. There are also important evidences which propose harmful effects of smoking on periodontal tissues including alveolar bone. The purpose of this study was to assess the relationship between smoking and prevalence and severity of vertical bone defects.Materials and Methods: This case-control study consisted of 71 individuals with angular bone defects (case) and 69 individuals without angular bone defects (control) between 18 to 70 years old. People were selected by radiography, examining and filling up the questionnaire. Vertical bone defect was defined as interproximal bone resorption to the extent of ³2mm with a clear angel towards the mesial or distal of root. Data were analyzed using Chi-square and Logistic Regression test.Results: The mean age of studied individuals was 37.14 years (±12.72). Among people with angular bone defects, 21.1% were light smokers and 25.4% were moderate-heavy smokers. There was a significant difference between smokers and nonsmokers in terms of smoking status and the chance of having angular bone defects (P=0.001). Simultaneous study of the effect of sex, age, brushing and smoking status showed that except sex, other variables had a significant effect on the angular bone defects. The chance of having angular bone defects in light and heavymoderate smokers was higher than that of nonsmokers (adjusted OR=4.17 and adjusted OR=3.87, respectively).Conclusion: These observations propose that smoking is related to increase in prevalence and severity of vertical bone defects. Smoking is considered as a potential risk factor for vertical periodontal bone loss.

The goal of root canal therapy is cleaning and obturation of the entire root canal system. A thorough knowledge of root and root canal morphology and its possible variations are essential and will help to reduce endodontic failure caused by incomplete root canal preparation and obturation. In this study, one case of maxillary molar with two palatal roots in a 40-year-old woman is reported.