Journal of Dental School
Year:2006 | Volume:24 | Issue:2 (69)|Papers Count:18

Background & Aim: Dental implants should be surrounded with at least 1 mm bone. Assessing ridge width is an important part to achieve this goal. The use of ridge mapping to assess bone levels available avoids some of the problems associated with CT-Scanning. The aim of this study was to assess the accuracy of ridge-mapping compared to CT-Scan in determination of bony ridge widths.Methods & Materials: A modified surgical stent was designed to locate the beaks of ridge-mapping calipers at the same points on the jaw during the two measurements. 52 implant sites in 11 cases were studied. Measurements were made at 3mm and 6mm distances from the crest of the ridge in each implant sites. Two measurements, one on CTScan and the other one by caliper was done. Mean, Standard deviation, paired sample test (t-value, p-value), a within subject correlation coefficient, coefficient of reliability and 95% CI for coefficient of reliability was calculated.Results: A total of 104 measurements were made at 52 implant placement sites. According to the paired sample test there were not significantly different between CT-Scan and ridge-mapping measurements (P>0.05).Conclusion: The present results suggest that it is possible to use ridge-mapping to determine the ridge-width instead of CT-Scan. Ridge-mapping can provide reliable information about bone levels, which result in avoiding exposure to radiation and reducing the cost for the patients. However it is suggested to use other methods for complicated patients.

Background & Aim: Oral surgical procedures are usually accompanied with pain, swelling and other discomforts, which cause patients to fear. Several types of drugs have been used for reduction of postoperative swelling and trismus. This study was carried out to evaluate the effect of preoperatively administered LV Dexamethazon in reduction of swelling and trismus caused by surgical removal of lower third molar.Method & Subjects: This double blind clinical trial was performed on 30 patients (17 female, 13 males) with age range of 18-31 years. All patients had bilateral impacted lower third molar. Equal amounts of distilled water versus dexamethazon were injected intravenusly for each side randomly. The distance between two mandibular gonial angles and mouth opening inter incising was recorded preoperatively and 2 day's & one week postoperatively. T test analysis was used as statistical procedure.Results: The study showed that there is significant difference between placebo and dexamethazon groups considering the variables studied.Conclusion: The study confirmed the positive effect of preoperatively administered LV Dexamethazon in reduction of swelling and trismus caused by surgical removal of lower impacted third molar.

Background & Aim: Injection is one of the dental procedures which has the most negative reflection in dentistry and reducing its pain is one of the most serious problems in pediatric dentistry. Since the application of topical anesthetics is in contrast and doubts and there was no study done in Iran for it, this research was done to determine the effect of Benzocaine 18%on reducing pain during injection in children referred to dental faculty of Azad University, 2004.Methods & Materials: In this sequential randomized double blind clinical trial, the kids were in need of bilateral posterior infiltration of Maxilla for Cl I restoration .Child cooperation was classified within level 3 or 4 and they could not have any systemic disease or abcess& fistula in that area. The gels used were Benzocaine 18% and Fluoride (with the same color and flavor). Randomly one of the gels was applied for 2 minutes and after 10 minutes rest, the procedure was repeated contralaterally with the other gel. For measuring the pain CPS & VAS were used and the child was asked about the preference gel Data of CPS & VAS were statistically analyzed by Mann Whitney and Chi Square, of preference by sign test. The relation between VAS & CPS was measured by Spearman.Results: The study was performed on 6-12 year old kids (50 samples). Two of them were ignored due to instability in responses .In VAS, score of placebo gel was 551 and Benzocaine was 530.In CPS score of placebo gel was 519 and Benzocaine was 562 which were not significant by Mann Whitney. Amount of pain of "not & low" in 2 groups were similar and depending of "not & low" and "medium & severe" was insignificant by Chi square. As the preference, results show 3 cases (13%) preferred placebo and 9 cases (40%) Benzocaine which was insignificant by Sign test.Relation between VAS & CPS in control group was 0.21(21%) and in case group was 0.17(17%) which was poor depending on Speannan test.Conclusion: Benzocaine 18% did not reduce children's pain during injection so it can be eliminated. Other investigations are necessary to specify replacement of other methods so that the best way to reduce the pain of injection will be known.

Background &Aim: Erosion has been defined as the irreversible loss of dental hard tissue by a chemical process not involving bacteria. Dental erosion is an important cause of tooth tissue loss in both children and adults. Acids of intrinsic and extrinsic origin (gastric juice and acidic food staffs, beverages) are thought to be the main etiologic factors for dental erosion. The reported incidence of tooth erosion caused by soft drinks has been increasingly documented because soft drinks consumption has increased dramatically over two decades. The aim of this study was to evaluate the PH and TA of some of the Iranian carbonated soft drinks.Methods and Materials: An experimental Lab study was designed in Kerman for controlling PH and Titratable Acidity (TA) of Iranian carbonated drinks cola, orange and Lemon lime. Twenty - three kinds of drink were collected from three different groups (cola, orange, lemon lime) and their PH and TA were assessed 10 days, 2 months and 4 months after their production. Data were analyzed with SPSS, paired T test and ANOVA.Results: Analysis of data showed PH of soft drinks was 2.5-3. PH of cola drinks was less than other drinks (P<0.05). TA of orange drinks was more than other drinks but there wasn't any significant different between groups of drinks. TA of soft drinks was 0.11-0.14.Conclusion: Chemical tests indicate that all soft drinks in this study have approximately suitable PH & TA.

Background & Aim: One of the important aspects of diagnosis and treatment planning in the mixed dentition is estimation of the size of unerupted permanent teeth (canines and premolars). One of the most commonly used prediction methods is Tanaka and Johnston. It is based on data from a sample of children of Northern European descent. The accuracy of this method when applied to a different ethnic population is questionable. The aim of this study was to determine new regression equations for predicting the size of unerupted canines and premolars in Ahwaz.Methods & Materials: This study was a analytic and cross - sectional investigation with randomized cluster sampling in Ahwaz. Forty five students 14 to 18 years old (32 girls, 22 boys) were selected between 320 students and their plaster models was prepared. All students had all relevant teeth fully erupted, class I canine and molar relationship and presented no proximal caries or fillings, morphological anomalies, missing teeth or occlusal abrasion and bruxism. The mesiodistal crown diameters of the permanent teeth was measured with using sharpend boley gage (accuracy 0.01 mm). By using of regression, correlation analyses and T- Test, the data from this study was analyzed. Results: In this study the following results were found. The correlation coefficient between the independent variable, lower incisor's width (LI1I2), canines and premolars. The following regression equations were found in Ahwaz for predicting mesiodistal width of the canines and premolars on based the mesiodistal width of the four mandibular incisors in simple form with 0.5 millimeters overestimation.TUCPM1PM2= 10.5+ The mesiodistal crown diameters of lower incisors/2TUCPM1PM2= 10 + The mesiodistal crown diameters of lower incisors/2The results indicated that new regression equations more closely with the 50% level Moyers probability tables for the maxilla and mandible.Conclusion: Because the effect of race and ethnic on teeth size we must be find relationship between different teeth group for different race and ethnic group. In this investigation there are following relationship between maxillary and mandibular canines and premolars with mandibular incisors:TUCPM1PM2= 10.5+ The mesiodistal crown diameters of lower incisors/2TUCPM1PM2= 10+ The mesiodistal crown diameters of lower incisors/2New regression equations more closely with the 50% level Moyers probability tables for the maxilla and mandible.

Background & Aim: According to presence of immune system factors in chronic periapical lesions, hypersensitivity reactions may have some role in pathogenesis of these lesions. Up to now, among the factors participating in type I hypersensitivity reaction, only one of them has been studied. So the aim of this study was to evaluate the relationship between the presence of IgE & number of mast cell and the presence of IgE and histamin in human dental chronic periapical lesions.Methods & Subjects: In this analytical study, 40 specimens were collected from 39 patients. After extraction of the lesions, they were divided into two sections. Half of the sections were used for explant culture and were maintained for 3 days. Then sandwich enzyme linked immunosorbent assay (ELISA) was used to determine the presence and concentration of IgE and histamine. Based on the presence of IgE, the samples were divided into case (with IgE) and control (without IgE) groups. The other sections were used for estimating the number of mast cells by histopathological technique. Mann - whitney U test and Spearman correlation coefficient were used to analyze the data.Results: The average percent of mast cells in case and control groups was respectively, 10.25±7.02 and 6.9±4.09. There was no difference between the case and control groups regarding the number of mast cells and histamine concentration. Also there was not any correlation between IgE and mast cells or IgE and histamin.Conclusion: It is concluded that hypersensitivity reaction type I possibly does not have any role in pathogenesis of chronic periapical lesions.

Background &Aim: Improvement of mechanical properties by increasing the degree of polymerization of composite resin is very important. As light intensity is a major factor in adequate polymerization, high intensity light units with decreased exposure time have been used. The aim of this study was to compare the effect of different light intensities on the flexural strength of composite resin.Methods & Materials: In this experimental study, 70 specimens of composite resin (Z100) were prepared by using stainless steel mold (25x2.5x 2mm).The composites were condensed into the mold, Mylar strip was put on them and they were irradiated with halogen light units under different exposure conditions. 1- 400mw/cm2 for 40S (control group). 2- 700mw/cm2 for 23S, 3- 1120 mw/cm2 for 14.3S, 4- 700 mw/cm2 for 40S, 5- 1120mw/cm2 for 10S, 6- 1120mw/cm2 for 23S, 7- 1120mw/cm2 in soft start method. Ten minutes after exposure, the specimens were taken out of the mold and after 24 hours storage in 37°C, they were inserted in Instron machine for three point bending test. ANOVA and Kruskal - wallis tests were used to determine the significant differences among the flexural strength means of all groups.Results: The means of flexural strength of the seven groups were 122.52, 126.48, 133.71, 135.75, 123.21, 131.55 and 121.11 MPa. There was no significant difference among the means of flexural strength of the seven groups. Conclusion: Flexural strength of resin composite was insensitive to the rate of polymerization. Rapid polymerization with high light intensity during short exposure time had no adverse effect on flexural strength of resin composite.

Background & Aim: Diabetes Mellitus is the most common metabolic condition. This disease is not diagnosed in approximately 1/2 of the patients actually suffering from the disease. In addition, the prevalence of diabetes mellitus is more than in patients with periodontitis when compared to periodontally healthy subjects. Thus, a high number of patients with periodontitis may have undiagnosed Diabetes Mellitus. The aim of this study was to evaluate the correlation between capillary blood glucose level and sulcular blood glucose level and blood from gingival tissues during routine periodontal examination used form gingival tissues during routine periodontal examination used for determining glucose level.Methods & Subjects: Thirty non-diabetic and 30 diabetic patients with moderate or severe periodontitis were included and subjected to routine clinical periodontal examination. Blood oozing from gingival tissues of anterior teeth following periodontal pocket probing was collected with the stick of glucose self monitoring devices. As control, finger stick capillary blood was taken. Statistical analysis was performed by Pearson's correlation coefficient and t tests.Results: The patient blood glucose levels ranged from 58 mg/dl to 477 mg/dl and the value of blood samples taken from gingival or finger tip showed a very high intra patient correlation (r = 0.99, P< 0.0001). The results suggested that blood oozig during routine periodontal examination may be used for Diabetes Mellitus screening in a dental office setting.Conclusion: Since there is correlation between sulcular glucose blood level and capillary glucose blood level, we can use this method for screening diabetic patient in dental clinic.

Background & Aim: Considering the pathogenesis of nursing caries, the emphasis has more been focused on microorganisms, especially streptocucus mutans, There are also multiple factors interfering the onset of this disease, the immunological responses of the host are one of the them. Among different immune factors, there has been little attention to the role of neutrophils, though they act as the frontiers in defense mechanism. So this study was done with the aim of evaluating the relation of salivary neutrophil percent in children with baby bottle tooth decay and caries free children in 3-5 years old kids in Tehran kindergartens.Methods & Subjects: Thirty - six children with nursing caries and 36 caries free kids were selected for this analytical cross sectional study. All the basic variables which might had affected on neutrophil rate were omitted. One ml of saliva was obtained from all children and a fruity was prepared for each case to compare the results. To prevent the bias all the samples were coded. The analysis was performed by SPSS ver10.0 software and chi - square analysis. Results: The neutrophils count in samples with early childhood caries was 23.6±11.4 and 17.6±11.2 in caries free kids. Saliva neutrophil count in kids with nursing caries was significantly higher than caries free children (P<0.02). Conclusion: In nursing caries the polymorphonuclears (Neutrophils) migrate into the oral cavity and a significant increase in their rate is observed in saliva, indicating their effort for defence.

Background & Aim: Lichen planus is a common inflammatory disease of skin and mucosa. The erosive and bollouse types are so painful which inhibit oral hygiene care, therefore increase of the caries and periodontal diseases are risk factors for malignant transformation or malignant development. Intra lesional injection of Triamcinolone Acetonide has shown a better result with no side effects in comparison with the systemic treatments. The aim of this study was to evaluate the effect of 30mg Triamcinolone Acetonide intra lesional injection every week for four weeks on treatment and prevention of recurrence of the lesions.Methods & Subjects: Twenty patients with erosive oral Lichen planus and without any systemic diseases were chosen for this case control study. After the biopsy and histopathologic documentation, 30 mg Triamcinolone Acetonide with 3ml normal salin (1/4) were injected intra lesional every week for four weeks.Results: There was a significant increase in mean size of the lesions in control group (1.1342 cm2), whear as there was a significant decrease in mean size of the lesions in case group (8.096 cm2).Conclusion: It seems that intra lesional injection of 30mg Triamcinolone Acetonide every week for four weeks in erosive oral Lichen planus has a good effect on healing of the lesions in comparison with local and systemic treatments that have less effect in association with many side effects.

Background &Aim: This double - blind clinical study compared the pain reducing effect of Celecoxib and Ibuprofen in patients with severe endodontically originated pain.Methods &Materials: A total of 30 patients presenting with severe pulpally originated pain consented to a single - dose oral administration of 100 mg of Celecoxib or 400 mg of Ibuprofen.Patients - reported Visual Analog Scale (VAS) ratings of pain intensity were recorded at every 15 min for 90 min after drug administration. Data were analyzed using student's t test.Results: Results indicated that at the 15, 30, 45, 60 and 75 min periods, both Celecoxib and Ibuprofen provided pain relief, but there was no significant difference between them. At 90 min period, Celecoxib showed significantly better pain relief than Ibuprofen (P<0.01).Conclusion: Based on the results of this study, it seems that Celecoxib has better pain reducing effect than Ibuprofen.

Background & Aim: Endodontically treated molars have the risk of fracture. The purpose of this study was to determine the fracture strength of endodontically treated molars after treatment with various types of cavity preparations and time of load cycling intervals.Methods & Materials: In this conventional and parallel study, one hundred and seventeen extracted human molars were selected and randomly divided into 3 groups (n=39) based on cavity preparations of MOD, MOD accompanying with lingual cusp reduction (CCL) and MOD with lingual and buccal cusp reduction (CCLB). The control group consisted of thirteen intact molars. All of the teeth were filled with a packable composite (Tetric Ceram HB). Each group was divided into three subgroups (n=13) based on the load cycling: 1) without any load cycles, 2) 1000,000 and 3) 2000000 load cycles .Then the specimens were fractured in Instron testing machine by a crosshead speed of 5 mm/min. The statistical analysis (ANOVA and Duncan's test) was performed for analysis of data (a =0.05).Results: 1) There was statistically interaction between two variables of cavity preparation and time interval (P<0.05). 2) In MOD group the most fracture strength was observed at the base line (P<0.05) and there was no significant difference between four and eight year groups. 3) The least fracture strength was related to CCBL group at the base line (P<0.05). 4) The most fracture strength was related to CCL group in four and eight year groups (P<0.05). The most fracture strength was observed in control group (intact teeth).Conclusion: The adhesive packable composite restorations in molars after lingual cusp capping could create a fracture strength similar to intact teeth until four years.

Background &Aim: Optimum utilization of human and financial resources is one of the most important concerns of management of any institutions and educational institutions are no exception to this rule. The aim of this study was two fold. Firstly, to obtain an estimate of the average annual cost for training general practitioner's dentistry students for the year 1382-1383. Secondly, to investigate the main contributing factors to this overall cost and subsequently to suggest guidelines for reduction of this overall cost without affecting the quality and standard of the course.Methods & Materials: In this descriptive and applied study a population consisting of all the general practitioner dental students in the year 1382-1383has been considered. A check list of items for expenses resulting indirectly from the activities of students and the equipments used for this purpose was prepared. Similarly a check list of items was prepared for equipments used by students and also expenses arising directly as a result of student activities. To calculate the overall cost the costs due to maintenance, depreciation and administration was added to the direct and indirect expenses. To calculate the direct and indirect expenses arising from the activities of the students the sessions and also cost of materials used were estimated.The administration cost was calculated as the sum of contributions from educational planning, research plarming, library, sport centers, students welfare, internet facilities, EDC, cultural and political promotion fairs and development of university's communal area.The cost of depreciation was estimated per student as the sum of contributions due to the depreciation of dental school buildings, administration buildings, dentistry equipments and goods transportation vehicles.Results: According to the data gathered in this study the overall armual cost for the general practitioner doctorate degree in dentistry are as follows:23/647/917 for the first year, 23/829/083 for the second year, 35/267/276 for the third year, 53/126/533 for the fourth year, 48/409/587 for the fifth year and 36/762/048 for the sixth year.Conclusion: Overal cost of general practitioner's doctorate degree course in dentistry at Shaheed Beheshti University Dental School is 2211050/474Rials.

Background and Aim: Periodontal disease is a common reason for oral diseases and tooth loss after ages of 35. According to lack of new information in Iran, our purpose was to determine periodontal condition using CPI at Tehran province in 15-19 and 35-44 individuals. (2001-2002)Methods &Materials: The study had a descriptive cross-sectional design and consisted of 1200 sample in two groups of age. Sampling method was randomized cluster with linear systematic classification. Variables considered were age, gender, residence, educational level, CPI, plaque index, (PI), and tobacco use (for samples 35-44 years of age). After data entry in EPI ver. 6 software periodontal condition was assessed by means of CPI and relation of CPI and PI with age, residence, educational level and tobacco use were evaluated by using chi-square test.Results: CPI in group (15-19) was:Code 0: 10.5%,Code 1: 30.4%, Code 2: 33.8%, Code 3: 24.1%, Code 4: 1.2%,Code X: 0%. And median of plaque index (PI) was Code 3 with prevalence of 82.5%.CPI in 35-44 years was:Code 0: 1%, Code 1: 8.3%, Code 2: 31.9%, Code 3: 38.6%, Code 4: 16.4%, Code X: 3.8% Conclusion: In first In first group, most of the problems can be solved only by hygiene instructions, but, in second group according to increasing pocket depth, we need care by specialists.

Background & Aim: Patients referred for dental treatment may have some systemic diseases. The aim of this study was to assess the history of using medicine in the patients referred to dental school.Methods & Materials: In this descriptive epidemiologic investigation performed with cross sectional method and simple randomized sampling, data forms were completed with only one questionnaire. Age, gender and the history of medication were evaluated in 600 patients refer to Oral Medicine department.Results: From the 600 referred patients, 56% were female and 44% were male. The range of age was from 15 to 75 years, most of the patients had 25-35 years of age. 34% of them had systemic disease. The most common disease in all of them were allergy (6.83%), gaster intestinal disease (6.33%), cardiac disease (5.5%) hypertension (4.16%), tyroid disease (3.63%) and renal disease, anemia-diabetes and arthroskeletal disease. 30.83% of the all were using drugs, The prevalence of using drug was different in the males and females. The most common drugs used by all of them was NSAID and analgesics - Antyhistamins, antibiotics. GI drugs, cardiac drugs, antihypertension and tyroid drugs had the next prevalence. Conclusion: In the present study, we found that there is high usage of drugs in patients who need dental treatments; regarding to the probability of drugs interactions it's necessary for dental students to become well educated in this aspect.

Background & Aim: Evidence-based medicine (EBM) has been defined as the process of 'systematically finding, appraising and using contemporary research as the basis for clinical practice. This definition can equally be applied to dentistry. The practice of EBM has evolved to mean the integration of individual clinical experience with the best available evidence from systematic research. In this article, the places to find evidences are discussed.Discussion: There are several defined stages involved in applying the evidence-based approach to clinical practice. The first is to identify the need for evidence about an individual patient's problem and convert these needs to a clear clinical question. We then need to search the literature for relevant clinical papers which will provide the evidence to answer our question. These papers then need to be evaluated to assess their quality, validity, and clinical usefulness. If the evidence is not valid it must be ignored. Alternatively, if the evidence is valid and clinically useful it will either support or contradict our current clinical practice. If it supports us, then we continue as before, being confident that our patients are receiving the most appropriate care. However, if it contradicts our current practice we can still choose to ignore it, but preferably, we will look at changing our practice to adapt to the new findings subject of course, to acceptability, availability, and affordability. This process is not static and we must be aware that new evidence is always becoming available so we need to evaluate our performance and update our practices to ensure that we continue to provide the most appropriate care for our patients. The role and importance of Text Books and Literature Reviews, Systematic Reviews, Electronic Databases, the Internet, Hand searching and the Cochrane Collaboration are discussed.