Journal of Dental School
Year:2007 | Volume:25 | Issue:2 (72)|Papers Count:15

Background and Aim: The pain after root canal treatment is one of the main problems for patient and dentist. Various drugs were studied for alleviating the pain after treatment. The purpose of this study was evaluation of various medication methods on the incidence of post treatment endodontic pain in necrotic teeth.Methods & Materials: In this controlled double blind clinical trial, 120 patients with single canal teeth and necrotic pulps were selected. The patients were divided into six groups and randomly received drugs in one of the following ways: Group A, 2gr Amoxicillin one hour before treatment. Group B, 2gr Amoxicillin plus 4mg Betamethasone one hour before treatment. In group C, 2gr placebo (control group) one hour before treatment Group D, 500 mg Amoxicillin immediately after treatment and continued every 8 hours for 4 days. Group E, the same treatment as group D was performed expect that, 4mg Betamethasone was added to Amoxicillin. Group F, the same treatment as group D was performed, but placebo was used instead of Amoxicillin.Root canal therapy was accomplished with step back technique and lateral condensation method. Evaluation of incidence of pain was recorded 6, 12,24,48 and 72 hours after treatment. Data were analyzed by Kruskall-wallis and Mann-whitney tests.Result: The results of this study in various intervals showed that there was no significant difference in the incidence of post treatment endodontic pain between those patients who received Amoxicillin or Betamethasone (A,B,D, E,F) and those who used placebo (control group C, F). Most of patients that had severe pain received placebo (C and F groups).Conclusion: Oral administration of corticosteroids plus antibiotic in cases with necrotic pulp did not significantly reduce post treatment endodontic pain.

Background and Aim: Template analysis is a method which consists of mean graphic face profile so that shows the discrepancies sites only by direct observation of superimposed template on the patient's cephalogram tracing. The aim of this study was to prepare a template based on concepts of natural head position for Tabriz's adults.Methods & Materials: Sixty two lateral cephalograms based on natural head position which were obtained from students of Tabriz dentistry faculty with normal occlusion and proportional facial profile were studied. Assuming the N point as a coordinate origin and true horizontal and vertical lines as bases of coordinate axials, length and width of 32 landmarks on hard and soft tissues were determined. Mean and SD of all landmarks were determined using SPSS analysis method.Result: A new template was designed by tracing average profile image for males and females separately in five different sizes.Conclusion: The template analysis based on NHP could have both advantages of using extracranial references and utilizing a quick analyzing method. The natural head position concept and the special design for orthognathic surgery, are two particular features of this template compared with the other templates described before.

Background and Aim: Since tip projection is an important factor for the nose esthetics, one of the results in rhinoplasty is maintenance increase or decrease of nasal tip. The aim of this research was to measure nasal tip dropping in profile after rhinoplasties done on Maxillofacial Department of Taleghani Hospital, Tehran in 2003- 2004.Methods & Materials: In this quasi experimental study, nasal tip dropping 2 months and 6 months after surgery in comparison with 20 days post operation in 28 patients were measured via profile photographs. Various variables such as tip projection, nasal length (NL); nasolabial angle (NLA) and (nose+upper lip length)/projection (N+UL/P) were calculated by computer software; with accuracy of 0.01 mm and 0.1 degree. Paired T and ANOVA tests were used to compare the changes.Result: Tip projection diminished slightly within 20 days to 6 months after rhinoplasty which means the tip had a little posterior movement. Nasolabial, angle showed significant decrease (P<0.001) and increase in nose length was apparent (P<0.001). Changes indicated the inferior dropping of nasal tip. Nose tip change was seen after: 2 months and continued 6 months postoperatively. The postoperative changes between 2D days and 2 months, 2 and 6 months, and 20 days and 6 months for NL, NLA, N+UUP were significant in all cases (P<0.05). Nasal tip changes were greater in male than female but patient's age seemed not important. Septoplasty and tip graft did not have significant effect on nose tip.Conclusion: Nose tip moved inferiorly and posteriorly within 20 days and 6 months after surgery but inferior movement was more than posterior movement.

Background & Aim: Extraction of first premolars and their influence on the third molars' eruption and impaction has been of concern to dental profession. The aim of this study, was to determine the relation between the changes of third molar angulation and the first premolar extraction in orthodontic treatment.Materials and Methods: This analytical study was carried out on total 90 subjects selected from two orthodontic clinics. Forty five subjects (14 males and 31 females) 14.46±1.64 years old treated with extraction of four first premolars (extraction group) and the other 45 subjects (13 males, 32 females) 13.9±1.99 years old treated by nonextraction were studied. Lateral cephalometric and panoramic films were studied before and after treatment. Eight angles in panoramic, four angles and 4 linear variables on the lateral cephalometric films were measured. Age, gender, amount of crowding in both dental arches and treatment duration were matched in the two groups. Student t and chi square tests were used to analyze the data.Results: The upper eruption space and the lower eruption spaces were more in extraction group and the difference was significant (P=0.02, P=0.004, P<0.001). The changes of third molar angulation were not significant between the two groups. Eruption rate of the third molars in both arches were more in extraction group and the difference was significant (P<0.001).Conclusion: Extraction of the first premolars did not influence the changes in the third molar angulation, while it affected the third molar eruption by space creation. It seems that extraction of the first premolars is not a way for secure eruption of the third molar.

Background & Aim: Since making a proper orthodontic treatment plan is highly based on a thorough understanding of growth changes in dent facial complex and due to relatively high prevalence of Class II malocclusion cases, this study was conducted to evaluate dent skeletal growth changes in 7-12 year old class II subjects.Methods & Materials: In this longitudinal study, 8 schools were randomly selected in Tehran. After examination of 1886 students, 73 subjects were selected according to special criteria, all demonstrating a Cl II molar and canine relationship. Lateral cephalogram radiographs were obtained from these individuals under NHP position in dental school of Islamic Azad University. After a period of 2 years 43 of them (23 males&20 females) could be recalled and again lateral cephalograms were taken under the same condition. The two series of cephalograms were traced and 26 angular and linear measurements were evaluated. Data were analyzed using Paired t, Wilcoxon and Mann Whitney U test.Result: All the 43 subjects in this research were categorized into 4 groups according to sex and age (7-9 and 10-12 year old). The 26 evaluated parameters demonstrated different dental and skeletal growth changes. Anterior cranial base in 7-9 years old boys and girls was respectively increased 2.54±0.58 and 2.56±1.52 mm, and increased 2±0.67 and 2.33±1.34 mm in 10-12 year old group (p<0.05).Effective maxillary length increased 4.13±2.01 and 3.06±2.46 mm in 7-9 years old boys and girls and 3.5±1.80 and 2.5±1.95 mm in 10-12 year old group (p<0.05). Efective mandibular length increased 5.67 ±2.65 and 6.19±2.83 mm in 7-9 years old boy and girl and 5.82±2.40 and 5.50±2.49 in 10-12 years old group (p<0.05). Ramal height significantly increased in the four groups (p<0.05).Conclusion: Results of this study can be used as control data for evaluation of orthodontic treatment procedures, especially those involving growth modifications.

Background & Aim: Fluoride released from restorative materials was known as an effective factor to prevent secondary caries. The purpose of this study was to compare the fluoride ion release from two conventional glass-ionomers; Ionocid-F and Fuji II and two Resin- modified glass-ionomers; Iono Gem LC and Fuji II Le. Methods & Materials: In this experimental study, five disc - shaped specimens (7x2mm) from each material were prepared. The specimens were placed in plastic containers with 10cc of de ionized water. The solutions were changed daily up to one week and thereafter every 12 days for three consecutive days. This regimen was repeated four times over a period of 2 months. Solutions were buffered with TISAB n and fluoride measurements were carried out using a fluoride ion-selective electrode connected to a pH ion-selective electrode meter. The results were converted to ppm. Statistical analysis was conducted using ANOVA and Scheffe.Result: All of the materials showed high initial release values which decreased significantly in second day. Ionocid-F (267.643±17.916 ppm) released significantly more fluoride ions during two months which followed by Iono Gem LC (101.284±10.068 ppm), Fuji n LC (23.276±2.609 ppm) and Fuji n (20.027±4.232 ppm). However, there was no significant difference between Fuji n LC and Fuji n.Conclusion: There was a wide variation of fluoride ion release from the materials but patterns of release were similar.

Background & Aim: It is of interest in restorative dentistry to maintain the pulp vitality after pulp exposure in traumatized teeth or during cavity preparation. If the tooth is asymptomatic, the exposure site is taken place in a saliva-free environment, direct pulp capping is recommended. Pulp capping agents must be biocompatible. The aim of this study was to compare the cytotoxic and inflammatory effects of four bonding agents on L929 fibroblast.Methods & Materials: In this experimental study, after culturing and pass aging these cells, samples of i Bond, Excite, One Step Plus and SE Bond, were prepared in capillary tubes and inserted in cultures. Cytotoxic effects were determined after 1, 24 hours and 7 days by MTT assay and for detecting the IL-6, fibroblast culture media were collected after 24 hours and assessed by ELISA. Statistical analyses were made using Kruskal-wallis and Mann - whitney U tests.Result: There was a significant difference of cytotoxicity among the groups after 1 and 24 hours (P=0.001, P=0.029 respectively). However, no significant difference was found. After 7 days, the amount of IL-6 production showed no significant difference among the groups.Conclusion: It was determined that i Bond had the least cytotoxic effects among the other groups. However, all the groups could induce the IL-6 secretion from fibroblasts.

Background and Aim: Reconstruction of craniofacial bone defects remains one of the most challenging problems encountered by maxillofacial surgeons. This study was designed to investigate the process of bone formation caused by implantation of octacalcium phosphate at mandibular alveolar ridge of rat.Methods & Materials: In this experimental animal study, 20 male Sprague Dawley rats were used. Synthetic octacalcium phosphate (OCP) was implanted into the bony defect measuring 3 mm in diameter and 2 mm in depth which was surgically created with a bur in the rat mandible. Bone formation at the alveolar ridge was examined histologically between I and 4 weeks after implantation.Result: Osteogenesis was initiated in the center of the defect between the OCP particles and multinucleated giant cells appeared on the implanted materials in 1 week. More apposition of new bone was observed on the implanted octacalcium phosphate in week 2. In addition to bone formation locally around the OCP particles, more apposition of new bone was observed near the defect margin in week 3. At week 4, the defect was almost completely filled with bone, which was in close contact with host bone and implanted OCP was surrounded by newly formed bone. In the control group, bone formation was observed only along and near the defect margin.Conclusion: Octacalcium phosphate could be used to enhance atrophic alveolar ridge or for filling a tooth socket after extraction.

Background and Aim: Regardless of calcium hydroxide use as a pulp capping material, in many cases the results were questionable and unsuccessful. Recently the Portland cement has been introduced as a pulp capping material.The aim of this study was to compare the histological changes of cat's dental pulp after capping with calcium hydroxide and Portland cement.Methods & Materials: This study was experimentally done with histological observation. Ten healthy adults and coeval cats were selected. After keeping them in standard condition for two weeks, class III cavities on distal of canine teeth were prepared and the pulp was exposed. In each jaw, one pulp was covered with calcium hydroxide A and the other treated with Portland cement B. Two cats were sacrificed after one week and the others were sacrificed after two months. Samples were assessed for severity of inflammation, dentinal bridge formation, necrosis, hyperemia and calcification. The data were analyzed by Mann-Whitney U test.Result: In one week, samples were similar to each other. After two months, dentinal bridge formation was found in 3 samples (20 percent) of group A and in 9 samples (60 percent) of group B. Inflammation was seen in 13 pulps (86.7 percent) of group A and 6 pulps (40 percent) of group B. Necrosis areas in group A were found in 10 pulps (66.7 percent) and in 5 samples (33.3 percent) of group B. Calcification was seen in 4 pulps (26.7 percent) of group A and in 6 samples of group B. Also odontoblastic layer was seen in 3 samples (20 percent) of each group.Conclusion: Portland cement showed more dentinal bridge formation, less inflammation and necrosis in comparison with that of calcium hydroxide when used as a pulp capping material (p< 0.05).

Background & Aim: The purpose of the present study is to evaluate the erosive potential of 4 fizzy drinks in Iran's Market by stereomicroscopy and SEMMaterials and Methods: Two Iranian made drinks (Cola zamzam and orange zamzam) and 2 imported ones (pepsi and Mirinda) were studied in this descriptive study as for their effects on tooth enamel (in vitro). 120 intact premolar teeth, extracted for orthodontic reasons were divided in to 3 groups (A, Band C). Each group exposed to one of the drinks for one out of 3 exposure times as follows: A: 15 minutes, B: 45 minutes and C: 12 hours. Each one of the 3 groups was subsequently divided in to 4 subgroups (each containing 10 teeth), each of which were exposed to 20 ml of one out of the 4 drinks. The surface exposed to drinks was the same in all tooth samples (a 5 mm in diameter semi circular window). Out of each of the 12 groups 2 teeth were selected randomly to be observed by SEM.Results: Morphological changes of enamel exposed to drinks were as follows: enamel discoloration, loss of glossy appearance and etching appearance of enamel in stereomicroscopic views. Variable degrees of loss of enamel prisms were observed in SEM views, affecting prism heads and sheaths primarily and then tails in longer incubation time.Depth and extent of erosion increased parallel with the rise in incubation time.Conclusion: All the drinks demonstrated a relatively high erosive potential on human permanent enamel.

Background & Aim: Dental plaque is the main etiological factor in periodontal diseases and there is no study on using chlorhexidine by fasting people. The purpose of this study was to evaluate the effects of using chlorhexidine mouthwash on dental plaque and gingival bleeding of fasting people.Methods & Materials: This experimental, controlled, cross-matched clinical trial study was implemented on thirty individuals (men and women) with the mean age of 40±1 year who attended Periodontic Department of Shaheed Beheshti University of Medical Sciences, and were divided randomly into two groups. Chlorhexidine mouthwash was used in the test group after dawn meal time (sahar) and breaking fasting time (eftar). The control group did not use any mouthwash. The plaque and gingival indices were measured in three stages; the first on 2-3 days before the beginning of Holy month of Ramadan, the second after the first ten days, and the third following 4 days of washout period. After the second ten days of Ramadan the test and control groups were replaced by each other. The findings were analyzed by T test between the two groups and by paired T test in each group.Result: The amount of dental plaque and gingival bleeding indices decreased significantly in individuals using chlorhexidine mouthwash (P<0.0001). The amount of dental plaque and gingival bleeding showed a statistically significant difference between the two groups with a better result for test group (P<0.001).Conclusion: Chlorhexidine mouthwash demonstrated positive effects on decreasing the amount of dental plaque and gingival bleeding in fasting people.

Background and Aim: Temporomandibular disorders (TMD) are defined as a series of signs and symptoms related to masticatory apparatus disorders. The prevalence of TMD (signs or symptoms) is high. Prevalent diagnostic and simple treatment can prevent the occurrence of sequeles. Due to different statistics on prevalence of TMD in different societies, the aim of the present study was to investigate the prevalence of temporomandibular disorders in dental clinics of Tehran city (2002).Methods & Materials: One thousands and five hundred and three subjects were collected from 20 clusters (clinics in Tehran). The research methods were descriptive and analytical three students with two supervising prosthodontists completed 2 questionnaires for signs & symptoms with ICC =0.819 and kappa =0.772 via observation and interview. For statistical analysis, t and chi - square tests were used.Result: The most frequently reported symptoms were: joint sounds (18.6%), muscle tenderness (9.1 %) and joint pain (7.7%). The most frequently signs were: joint sounds (30.2%), deviation patterns in mouth opening (23.4%), muscle tenderness (17%), joint pain (6%) and limited mouth opening (1.94%). The prevalence of symptoms and signs were 36.5% and 45.7%, with a significant relationship between them (P<0.001).The prevalence of TMD was 58.7%. There were significant relationships between TMD & bruxism and TMD & history of trauma (P<0.001). The prevalence of inflammatory disease of temporomandibular joint demonstrated significant difference between different age groups (P<0.001) and increased with age.Conclusion: The prevalence of TMD in clinical centers of Tehran was more than 50% of population. Due to the significant relationship between bruxism, trauma and prevalence of TMD, awareness of society for prevention and beginning the necessary treatments seems indispensible.

Background & Aim: Immunosuppressive drugs have special effects on bone remodeling during orthodontic tooth movement. This study aimed at investigating the effect of oral Cyclosporine A, an immunosuppressive drug, on the orthodontic tooth movement in rats.Methods & Materials: Eighty male Sprague-Dawley rats, weighting 220-280 gm, were used. The animals were randomly assigned into control and experimental groups, each one containing 40 rats. Each group included four subgroups, each of 10 rats. Four groups of rats were selected for the assessment of the effect of olive oil and stripping stress of the lower incisors for a period of 15 and 30 days. The two experimental sub-groups received 10 mg/kg Cyclosporine A by gastric gavages every 24 hours for 15 and 30 days. The other two experimental sub-groups received 30 mg/kg cyclosporine-A by gastric gavages every 24 hours for 15 and 30 days. A fixed orthodontic appliance consisting of nickel - titanium closed coil spring, was ligated between the maxillary right incisor and the first molar. The initial activating force was 60 gm. One way Analysis of Variance and Tukey were used for comparing tooth movement between the two groups and eight sub-groups.Results: The results showed that oral Cyclosporine A (30 mg/kg/30 day) could accelerate the rate of orthodontic tooth movement in rat (0.635±0.22 mm) (P<0.05). Also, its administration period was more effective than the dose itself. Olive oil and stripping stress could not increase the rate of tooth movement.Conclusion: Due to the findings of this study and predominant effect of cyclosporine A on orthodontic tooth movement in rats, the patients using cyclosporine A may have the chance of more tooth movement. Further studies are requested for evaluating the effect of Cyclosporine A on increasing tooth movement in accordance with its dose and duration.

Background & Aim: Surgical removal of lower third molars is a frequently performed procedure but prescribing antibiotic in third molar surgery remains controversial. This study determined the effects of preoperative and postoperative antibiotic therapy on the prevention of infections in bony impacted mandibular third molars' surgery.Methods & Subjects: In a prospective study of more than 9 months, a total of 100 bony impacted lower third molars were removed. The patient didn't show any sign of inflammation, swelling and systemic disease at the time of removal. Two groups were established. The first group (n=50) received 2 gr Amoxicillin one hour preoperatively. The second group (n=50) received oral Amoxicillin 500 mg for five days post-operatively. Clinical and radiologic features were recorded for each case. All patients were recalled on the seventh day after surgery to assess the pain, swelling, amount of mouth opening, the state of the wounds and the incidence of infection. Descriptive statistics, t and Mann-whitney tests were used to analyze the data.Results: The incidence of infection was 2% in the patients. There was no significant difference regarding the evaluated parameters between the two groups.Conclusion: The study showed that preoperative prophylactic antibiotic therapy in comparison with post operative oral prophylactic antibiotic treatment in the removal of lower third molars doesn't contribute to a better wound state, less pain, decreased swelling, increased mouth opening and prevention of infection after surgery.