JOURNAL OF ISLAMIC DENTAL ASSOCIATION OF IRAN (MAJALLAH-I-DANDANPIZISHKI)
Year:2005 | Volume:17 | Issue:3 (56)|Papers Count:19

Background and Aim: Dental anxiety is a major problem among patients and dentists leading to treatment disruption. The aim of this study was to determine dental fear and anxiety level among dental and medical students of Babol University of Medical Sciences.Materials and Methods: This cross-sectional descriptive-analytical study was carried out on 412 medical and dental students, Babol University of Medical Sciences using standardized questionnaires of DAS (Dental Anxiety Scale) and DFS (Dental Fear Scale).DAS and DFS scores along with information about age, sex, course of study, year of university entrance and history of dental office admission were analyzed by SPSS software, ANOVA and t tests.Results: Out of 296 (71.8%) medical students and 116 (28.2%) dental, 261 (63.3%) were males and 151 (36.7%) were females. The means of DAS and DFS scores were 8.03±3.73 and 34.13±16.75, respectively. Dental anxiety was reported among 54 (13.3%) students. The mean of dental anxiety score (DAS) in females and males were 8.59±3.99 and 7.03±2.95, respectively (P=0.000) and 8.2±3.82 and 7.61±3.46 (P=0.135) in medical and dental students, respectively. The mean of dental fear score in females and males were 35±17.94 and 31.99±15.29 (P=0.112), respectively. Injection and needle were reported as the most prevalent fear reasons.Conclusion: Dental fear and anxiety are not prevalent among students and not influenced by course of study and history of dental office admission, however; they are affected by sex and university grade.

Background and Aim: The effects of low level lasers on bone cellular activity, bone structure, bone healing, fibroblasts activity and inflammation process have been already investigated. Considering that orthodontic tooth movement is a complicated inflammatory process involving simultaneous bone apposition and resorption; the aim of this controlled study was to investigate the quantitative effects of a pulsed laser (Optodan) and a continuous laser (KLO3) on the orthodontic tooth movement in rabbits.Materials and Methods: This experimental study was conducted on 18 male albino rabbits divided into three equal groups of control, Optodan and KLO3. The first mandibular molars, in all groups, were under a four-ounce tension using NiTi-Closed coil springs. The control group was not irradiated but the laser groups were irradiated for nine days according to the periodontal therapeutic protocols. After sixteen days, following the termination of therapeutic regime; samples were sacrificed. The distance between distal surface of the first molar and the mesial surface of the second molar was measured with 0.05 mm accuracy.Data were subjected to the statistical tests of Kolmogrov Smimov and Variance analysis.Results: The mean orthodontic tooth movements of the first mandibular molars were 1.7±0.16mm in control group, 0.69±0.16mm in Optodan group and 0.86±0.13mm in KLO3 group. There were statistically significant difference, in orthodontic tooth movements, between the control and two other laser-irradiated groups (P<0.001).Conclusion: The findings of the present study imply that the amount of orthodontic tooth movement, following low level laser therapy, diminishes. Theoretically, the inhibitory effects of lasers on prostaglandins as a mediator in cellular response for tooth movement can be a justification for the mentioned biologic behavior.

Background and Aim: Peripheral Giant Cell Granuloma (PGCG) and peripheral ossifying fibroma (POF) are reactive gingival lesions producing bony tissue. This bony tissue can be woven or lamellar. The aim of this study was to compare the percent of bone and lamellar bone formation in PGCG and POF.Materials and Methods: Twenty- five cases of PGCG and twenty- five cases of POG were selected from the files of Oral pathology department of Tehran Faculty of Dentistry and Razi Pathobiology laboratory of Rasht. Clinical data including age, gender and location of lesion were recorder. The percent of bone and lamellar bone formation were determined using light microscope and polarized light. In order to compare the percentage of bone formation in lesions t - test was used and Pearson correlation coefficient was used to investigate the relationship between the mentioned variables and age.Results: The percent of bone and lamellar bone formation in PGCG were 9.06% and 45.05%, respectively and in POF were 8.72% and 35.18%, respectively showing no statistically significant difference in these two lesions. There was no relationship between the percent of bone formation and age, gender and also location of lesion in each of them. Mean volume of PGCG and POF lesions were 3.18cm3 and 1.34cm3, respectively.Conclusion: There was no statistically significant difference in the percent of bone formation between PGCG and POF. However, considering the difference between volumes it appears that bone formation may be greater in POF.

Background and Aim: There is a need for a material with high sealing ability to prevent bacterial and tissue secretions penetration in endodontic surgery. The aim of this study was to compare the microleakage of amalgam and MTA filling materials.Materials and Methods: Thirty-two single-rooted extracted human teeth were collected.Each tooth was apically resected and retroprepared to 3mm depth. Teeth were divided randomly into two groups of 13 teeth each. First group was retrofilled with amalgam and second group with MTA. All root surfaces, except the ending part, were covered with layers of nail polish. Following immersion in 2% methylene blue for 48 hours, the roots were sectioned and the depth of dye penetration was evaluated by computerized scanning and photoshop software. Results were evaluated by t-test.Results: It was shown that MTA microleakge was significantly less than that of amalgam.The mean dye penetrations of MTA and amalgam were 1.75mm and 3mm, respectively (pv=0.0001).Conclusion: The findings of the present study confirm the proper sealing ability of MTA.

Background and Aim: Impacted third molars, due to their extreme importance, have been paid attention by nearly most of dentistry disciplines. The causes of the removal of impacted third molars would be severe caries, TMJ pain, orthodontic treatments, crowding, pericoronitis, prosthetic treatments etc. The aim of the present study was to investigate the mentioned causes and to find out their relationship with different types of impaction.Materials and Methods: The causes of the removal of impacted third molars among 80 patients with the mean age of 25 years, 42 females and 38 males, referred the department of surgery, Dental Faculty, Tehran University of Medical Sciences were investigated.Panaorarnic and periapical radiographs were studied and all selected subjects were finally confirmed by the professors of surgery department for the removal of mandibular impacted third molars.Results: The causes of the removal of mandibular impacted third molars were ranked as follows: prophylactic procedures (26.25%), pericoronitis (23.75%), severe pain (22.5%), pathologic condition (11.25%), orthodontic and crowding reasons (10%), TMJ pain (5%) and prosthetic treatments (1.25%). Types of impaction were observed sequentially as: mesioangular (43.75%), vertical (32.5%) and horizontal (18.75%). No inverted and unusuall type were observerd.Conclusion: Pain, pericoronitis, prophylactic reasons and pathologic conditions were the most causes for the removal of mesioangular third molars. Pericoronitis and prophylactic reasons for the vertical type and pain along with prophylactic reasons for the horizontal type were mentioned as the most common causes.

Background and Aim: Pulpitis is the most important clinical problem in anesthesia for root canal treatment procedures. The application of cold is a traditional method for localized anesthesia in soft-tissue surgery. The aim of this study was to investigate the effects of cold (cryosurgery) and the combination of it with lidocaine-epinephrine for localized anesthesia in root canal treatment of inflamed pulps.Materials and Methods: In this experimental study, electrophysiological method was used to record the nerve response with nerogram waves in 16 pulps of cat which were stimulated with cold. For pulp inflammation, right and left canine teeth of mandible were exposed to oral cavity for 3 days then using surgical flap method, bone was excised and inferior alveolar nerve made available. Recording electrodes were places on inferior alveolar nerve and stimulator electrodes were put on canine teeth. Electrical stimulation was done basically without any intervention, after cryosurgery for cold effects and after lidocaine-epinephrine injection in mental foramen of mandible. All response waves were recorded. Waves were analyzed concerning latency and duration using ANOVA test.Results: Differences in latency and duration, without intervention and after cold between two groups were not statistically significant (P=0.97). The difference between basic response and after lidocaine-epinephrine injection response was significant (P<0.05) meaning that lidocaine-epinephrine reduced nerve response significantly.Conclusion: In pulp-inflamed teeth, cold decreased nerve response which was not statistically significant. Post cryosurgery lidocaine-epinephrine injection made irresponsible nerve in 81.3% of cases showing the ability of cold in local anesthesia of pulp inflamed teeth.

Background and Aim: Core preparation following cast post cementation is necessary. It seems that bur vibration may result in cracks and interfere with cement setting procedure. The aim of this study was to investigate the effects of different core preparation times on the retention of cemented cast post.Materials and Methods: Forty-eight intact canines were selected. After root canal theory posts and cores were fabricated for all samples. The specimens were randomly divided into four groups of twelve teeth. All posts and cores were cemented with zinc phosphate cement according to the manufacturer's instructions. In the first group (control) no preparation was made after cementation but cores of three other groups were prepared at different intervals (15 minutes, 30 minutes and 24 hours) after cementation. The preparations were made for 30 seconds incisally, 60 seconds palatally and 120 seconds axially. Then all specimens were stored in an incubatore for one week. An instron machine was used to determine the tensile force required for each post dislodgement. Data were subjected to one-way ANOVA at 0.05 level of significance.Results: The mean tensile forces for groups 1 to 4 were 650.58, 641.58, 616.45 and 549.87 Newton, respectively. The differences were not statistically significant.Conclusion: Considering the limitations of the present study, it can be concluded that with respect to the applied cement, different intervals of high-speed preparation have no significant negative effects on cast posts retention.

Background and Aim: One of the mostly used materials in removable prostheses are acrylic resins with various physical and mechanical properties. The impact strength of acrylic resins plays an important role in treatment success. The aim of this study was to compare the impact strength of Iranian made Acropars acrylic resin with British Standard as well as with Meliodent acrylic resin confirmed by American Dental Association (ADA).Materials and Methods: In this experimental study, 15 cubic rectangular shape samples of each acryles were prepared. The dimensions of these samples were 50x6x4mm. All measurements were performed using plastic impact tester. Data were analyzed by t-test.Results: The means of impact strengths were 1.21kj/m2 and 1-39kj/m2 for Acropars and Meliodent acrylic resins, respectively showing statistically significant difference between these two materials (P=0.26). Both of them were in the limitation of British Standard (at least 0.8kj/m2).Conclusion: There is no significant difference in impact strength between Acropars and Meliodent acryles and both of these materials comply with the requirements of British Standard (No:2487).

Background and Aim: Wetness of etched dentin surface is an important factor in the accomplishment of an effective bonding system, however; the required wetness has not been recognized yet. Different dentin bonding systems need various degrees of wetness to create a hybrid layer with the ideal quality. The aim of this study was to evaluate the effects of the wetness of etched dentin surface on nanoleakage and hybrid layer thickness.Materials and Methods: In this experimental parallel study, three kinds of dentin adhesives were used: One-coat Bond, Single Bond and Prime & Bond 2.1 and also three methods of drying the dentin surface after acid etching were used: Wet (blot dried), Semidry (3-second blast) and Dry (15-second drying). Class V cavities were prepared on 54 sound extracted premolars. After filling with a flowable composite and using silver nitrate, the rate of nonoleakage and the hybrid layer thickness were measured by SEM. Data were analyzed using ANOVA, DUNCAN test and correlation coefficient test at 95% level of confidence.Results: Nanoleakage was observed in all samples as the more dryness of etched dentin surface, the more significant nanoleakage was occurred. Moreover, in the most dried samples, the hybrid layer thickness was decreased significantly. The least rate of nanoleakage was observed in One-Coat Bond system along with wet condition and the highest rate was in Prime & Bond 2.1 in dry condition. In all studied systems the least nanoleakage and the highest hybrid layer thickness was related to wet highest hybrid layer thickness was related to wet condition meaning that the more hybrid layer thickness, the better seal of dentin.Conclusion: 1- Among the three tested dentin bonding systems, One-Coat Bond revealed the least rate of nanoleakage in wet condition.2- The highest rate of nanoleakage was observed in Prime & Bond 2.1 system in dry condition.3- There was statistically significant differences in nanoleakage rate of three different drying methods in each bonding system.4- There was a significant correlation, in nanoleakage increase and hybrid layer decrease,between all three bonding systems and three dentin drying methods.

Background and Aim: Cold-cure acrylic resins are commonly used for making interim prostheses, orthodontic appliances, denture repairs and special trays. Acrylic resins exhibit certain unavoidable changes that may affect on appliances accuracy. The aim of this study was to compare the linear dimensional changes of two cold - cure acrylic resins: Acropars and Meliodent.Materials and Methods: In this experimental laboratory study, twenty specimens in two groups of ten were made by Acropars OP and Meliodent acrylic resins according to the manufacturer's instructions. Dimensional changes were measured at 24, 48 and 72 hours after setting by a digital collis. The results were analyzed using t-test, t-paired test and repeated measure ANOVA.Results: In Acropars OP specimens, the difference between 48 hours and 72 hours (96.20±0.20 vs. 96.33±0.17) was significant (P3=0.006) but the differences between 24 (96.20±0.25) and 48 hours (P1 =0.958) and between 24 and 72 hours (P2=0.123) were not significant. In Melidoent specimens, the differences between all 3 days (0.37±0.47, 0.15±0.28 and 0.18±0.24) were significant (Pl=0.005, P=0.001 and P3=0.005). Moreover, the differences between Acropars and Meliodent acrylic resins on all three days (first: 95.82±0.25, second: 96.05±0.11 and third 96.15±0.10) were significant (P=0.003). The differences between mean groups and metallic dye, after three days, were significant in Meliodent group (P=0.000), but in significant in Acropars group (P=0.774).Conclusion: Meliodent self-cure resin had considerable dimensional changes when compared to Acropars resin. Maximum differences between these two types of acrylic resins were in the first 24 hours and the minimum difference was at 48 hours after polymerization.

Background and Aim: Toothache similar to other deep pains such as muscle pain is not only perceived at the painful tooth but is usually referred to other head and neck areas. In other words, localization of the pain source is difficult. The aim of this study was to determine the distribution pattern of the referred odontogenic pain from posterior teeth in different head and neck areas.Materials and Methods: In this cross-sectional study, 410 subjects with posterior toothache were recruited randomly from patients referred to the faculty of dentistry, department of diagnosis, surgery and endodontics. After clinical and radiographic examination, painful tooth and reported reference areas were determined. Data were subjected to SPSS software and the results were analyzed.Results: The most reported sites of pain referral were adjacent teeth and ear and the least sites were neck and posterior of head. Referral tooth pain distributed vertically with horizontal overlap.Conclusion: The results of this study indicate that referred odontogenic pain generally follows a vertical distribution with an union skin or lamination pattern in different head and neck tissues.

Introduction: For the first time, Abrikossof described granular cell tumor in 1926. It was firstly believed that this tumor originated from skeletal muscle but using electron microscope and immunohistochemistry technique (IHC). It has been generally accepted that this tumor has neural origin. Immunohistochemical markers such as S100, NSE and MBP are expressed by its tumoral cell.Synchronous lingual granular cell tumor and squamous cell carcinoma (SCC) is rare and only one case was reported in 1997 at Mountsinal faculty of medicine.Case Presentation: The present report is the second case in a 46-year-old man with persistent swelling and ulcer on dorsal tongue. Microscopic evaluation by H & E and IHC technique for S100 protein and cytokeratin marker continued this diagnosis.

Background and Aim: Canal preparation, as a basis for a successful endodontic treatment, is a big challenge in curved canals. The aim of this study was to evaluate canal transplantation and time of its preparation with stainless steel hand instrument (k-Type) and Ni-Ti rotary systems: Profile and Hero 642.Materials and Methods: In this interventional study, forty-two extracted curved (20°-50°) human mandibular molars were divided into three groups. Canal preparations were performed with stainless steel hand instruments and Ni-Ti rotary systems: profile and Bero 642. Pre and post instrumentation radiographic images were superimposed. Mercury was injected pre and post instrumentation for canal shape recognition. A computer-based software (Corel Draw 7) was used for the analysis of canal transportation. Time of canal preparation was also recorded. Data was subjected to ANOVA statistical test.Results: Stainless steel hand instrument (k-Type) shaped significantly greater canal transportation both mesiodistally and buccolingually than profile and Her0642 (P<0.05).Conclusion: Canal transportation and time of canal preparation in Ni-Ti rotary systems, were significantly less than stainless steel hand file Time of canal preparation with Ni-Ti rotary systems was significantly less than that of hand file (P<0.05).

Background and Aim: Frequency of pigmentation is different among various ethnic groups. The aim of this study was to determine the frequency of oral mucosal pigmentation and to find out the probable relationship between smoking and oral melanin pigmentation in patients referred to the facility of dentistry, Guilan University of Medical Sciences.Materials and Methods: This descriptive cross - sectional study was performed on 230 patients referred to the department of oral disease, Guilan Dental Facility, based on simple random sampling in 2003. Demographic data along with information about patients' smoking habits were recorded. All patients were examined clinically by an oral diseases specialist. Lesions were classified in three grades of mild, moderate and severe. data were subjected to SPSS 10 software and Chi-Square test.Results: In the studied population, 100 subjects (43.47%) had oral pigmentation, 26 of them had smoking habits. The common pigmentation sites were anterior maxillary and mandibualr attached gingival. Severe form of pigmentation was significantly higher in patients with smoking habits (P<0.05). Significant relationship was found between skin color and oral mucosal pigmentation (P<0.05).Conclusion: The present study showed that comparing to other parts of the world, the degree of pigmentation was moderate; this value was higher than European but lower than East Asian populations. In this study, smoking coilid only changes Faculty of Dentistry the severity of pigmentation.

Background and Aim: Lichen Planus is a chronic mucocutanouse disease. In its erosive type, due to accompanying ulcerative lesions, pain and soreness, treatment is necessary. The most common drug used for Oral Lichen Planus (OLP) are corticosteroids which lead to a lot of side effects in long term use. Therefore, the aim of the present study was to investigate cryotherapy, as an effective non-drug treatment for OLP.Materials and Methods: In this primary clinical study, 11 patients, 7 females and 4 males age ranging from 27 to 67 years old with the mean age of 47, affected with erosive oral Lichen Planus were selected. After filling a questionnaire by each patient, the size of the lesion was measured and the lesion was freezed through cyotherapy.Patients were followed in the first and second weeks after treatment and information on remedy, erithem, inflammation, pain and soreness were recorded and subjected to rank Wilcoxon test.Results: Statistically significant decrease, in the size of lesions was observed in the second ,week as compared with the first week using "signed-rank Wilcoxon" test (P=0.03). The comparison of erithem and inflammation between the second and the first weeks also showed a statistically significant decrease (P=0.007). Pain and soreness also showed a meaningful decrease in the first week comparing to pre-treatment as well as in the second week comparing to pre-treatment as well as in the second week comparing to the first week (P=0.007).Conclusion: According to the findings of the present study, cryotherapy can be suggested as an effective method for oral erosive Lichen Planus.