مجله دندانپزشکی دانشگاه علوم پزشکی تهران
سال شانزدهم شماره 3 (پیاپی 36، پاییز 1382)

Statement of Problem: Treatment of gingival recession defect and covering denuded root surfaces is one of the goals in periodontal therapy and several surgical techniques have been suggested in this field. The aim of this study was to perform a comparison on coronaliy repositioned flap procedure with and without the use of ethylenediaminoteraacetic acid (EDTA. 24%, pH=7) in the treatment of recession defects. In this randomized clinical trial study, 16 patients, aged 17-60 years, with a total of 27 miller class 1 isolated buccal gingival recession type defects of at least 2mm depth, and based on special criteria were investigated. After initial therapy, surgical recession coverage was performed as coronaliy advanced flap technique and EDTA gel conditioning (test) or coronaliy advanced flap alone (control). Clinical examination including assessments of oral hygiene, recession depth (RD), recession width (RW), width of keratinized tissue (KT), probing depth (PD) and probing attachment level (PAL)were performed before and 1, 2, 3 months after surgical treatment. The mean of initial RD, RW, KT, PT and PAL in the test group was 2.73, 3.17, 3.13, 1.1 and 3.83mm respectively and in the control group was 2.56, 3.03, 3.67, 1.25, 3.92mm respectively. The mean of these parameters 3 months after treatment in the test group were changed to 0.46, 1.97, 2.65, 0.67, 1.1 mm, corresponding figures for control teeth were 0.85, 2.98, 2.75, 1, 1.94, respectively. At 3 months after treatment the mean root coverage amounted to 83% (test) and 67% (control) which was a statistically significant difference (P=0.0067). Although a significant clinical difference was observed regarinding root coverage level, all other clinical variables were not statistically different, with the exception of probing attachment level (P=0.005). It was suggested that EDTA gel (24%, PLT=7) for 3 minutes as root conditioner and the coronaliy advanced flap procedure can be used as a predictable and successful method in the treatment of miller class I buccal gingiva! recession type defects.

Statement of Problem: Bone material density (BMD) is significantly decreased among postmenopausal women leading to the most common metabolic disease, osteoporosis.Multiple bone fractures are of the most important consequences of this disease, which cost too much for thesociety. One of the cheapest and most available methods for the diagnosis of bone density changes is bone radiomorphometric evaluation by conventional methods. Studies have also revealed that mandibular radiomorphometric indices in panoramic radiographs yield invaluable information, which can be used as a screening method to diagnose patients with decreasing bone density, and to determine normal values ofmandibular radiomorphometric indices among normal subjects in different populations. The aim of the present study was to investigate the mandibular radiomorphometric indices in panoramic radiographs among normal female population referring to maxillofacial radiology centers to determine their relationship with age and the total teeth number of the subjects under study. In this descriptive-analytic study, two mandibular radiomorphometric indices namely the Antegonial quantitative index (AI) and the Cortical qualitative index (MCI) were evaluated on 417 panoramic radiographs of a female normal population, aged more than 20 years which divided into five age group, by one maxillofacial radiologist as an observer. The relationship between these indices, and also with the number of teeth and age were investigated by variance and Pearson's analysis. Mean quantitative index (AI) was 3.54±54%mm. The prevalence of MCI index was C2: 71.5%,CI: 20.9%and C3: 7.7%. There was significant correlation between AI/MCI indices with age, dentition and also with each other.(P<0.0001). Based on the present study, with increasing age the mean AI and the number of teeth decrease significantly. MCI index also shows higher porosity in mandibular cortex (C3 index). Therefore, Mandibular radiomorphometric indices are useful in initial diagnosis and screening of patients with low bone mineral density (osteopenia, osteoporosis).

Statement of Problem: Halitosis refers to the unpleasant mouth odor leading to problems for the patient and his associates. Dentists with enough knowledge about the halitosis incidence with oral causes are able to plan and prevent it effectively. The aim of the present study was to determine the rate of halitosis incidence with oral causes among high school and guidance schoolgirls aged 13-17 years old in Ghazvin. Moreover, the relationship between some etiologic factors such oral hygiene, coated tongue with unpleasant mouth odor was investigated. The number of 700 female students, aged 13-17 years old was studied and 14 factors were recorded on a questionnaire for each subject. The related data were collected through direct clinical examination. The incidence of halitosis in this population was 28.9%. In addition, mouth odor was significantly associated with independent variables such as gingivitis, coated tongue, systemic disease and taking medicine,consumption odor producing materials and the level of oral hygiene. The most important factor causing malodor was poor oral hygiene. Also in other investigations gingivitis, coated tongue, tonsilitis, dental calculus and malocclusion were diagnosed as the most important causes for oral halitosis.

Statement of Problem: Computer Sciences, in radiology, like other fields, is of high importance. It should also be noted that the accuracy of the technique and work conditions affects the radiographs information considerably. There for, in order to get more accurate diagnostic information, it seems necessary to investigate different digitized radiographic techniques and to compare them with the conventional technique. The aim of this study was to compare the accuracy of conventional and digitized radiographic images by three digitization techniques in proximal caries detection. In this research study, sixty extracted human canines, premolars and molars were mounted in blocks and imaged on E-Kodak film, similar to bitewing radiographs. Ten bitewing radiographs were then scanned at 600 d.p.i with flat bed scanner and a digital camera, then digitized at 300 d.p.i with another digital camera. The digitized images were displayed randomly on a high-resolution monitor. Sixobservers assessed the caries status of 120 proximal surfaces by conventional and digitized images. The observer's scores were compared with the results of the macroscopic examination. Reliability of each technique was calculated. Data were analyzed using chi-square and ANOVA tests. No significant differences were detected between different techniques in intact proximal surfaces and enamel caries diagnosis. However, digital techniques were more sensitive in dentin caries detection (P<0.05). When conventional film images are digitized, medium resolution (300 d.p.i) seems to be sufficient. At this resolution the file size is decreased and there is no significant loss of the information necessary for caries diagnosis.

Statement of Problem: The goal of a successful endodontic surgery is to establish an adequate seal in apical region. Therefore during surgery, root-end resection is essential for an appropriate situation and proper access. The aim of this study was to determine the most appropriate root-end resection angle to establish adequate apical seal in periapical surgery Forty-five intact extracted human maxillary central incisors were randomly divided into three 15-tooth groups. The root canals were instrumented and then obturated using lateral condensation technique. AM roots were resected at 3mm from apical portion. Angles of root resection for each group were 0, 30 and 45 degrees. Then all teeth surfaces, except the cut ones, were covered with nail polish and immersed in methylen blue for 7 days. After 7 days, nail polish was removed from the surfaces and samples were split in buccolingual direction. Then, dye penetration (mm) was measured using a stereozoom microscope (Loupe) [X4 magnification] and eye lens. In order to analyze the data, unilateral variance analysis was used. The values of dye penetration were: 7.23±3.34 (0°), 8.46±3.01(30°) and 9.74±4.11 (45°). There was no significant difference between three groups (P>0.05). It is suggested that the angle of root-end resection put a limited effect on apical seal if retrograde cavity depth is increased.

Statement of Problelem: Lichen plannus is a relatively common mucotanous disorder, due to accompanying burning sensation and pain in addition to its malignant transformation, has potential importance. On the other hand, B and C hepatitis are of the five most common death causes, resulting in significant disease spread problems among dentists. As a result, the relationship between these two disorders has been recently investigated. The aim of the present study was to investigate the oral Lichen plannus prevalence among patients with B and C hepatitis. In this case series study, 500 patients with B, C hepatitis, 3 04 female and 369 male with the mean age of 39.09±13.13 (the youngest was 4 and the oldest was 72 years old), who referred to the hepatitis center of Shariati hospital, Transfusion organization and Hemophilia center, from August 2001 to August 2002, were evaluated. The information about all white lesions that couldnt be scraped was recorded on a questionnaire for each patient. To analyze the data, t and Fisher tests were used. Two hundred and eighty nine patients were MBS Ag" 223 were HCVAb", 12 were positive for both types of hepatitis and 23 were cyrotic. From among these patients, 3 subjects were with oral Lichen plannus (0.6%), one belonged to HBS Ag1 group (0.35%), (P=0.38) and two patients belonged to HCV Ab' (0.9%),(P=0.44). These results showed no statistically significant relationship between Lichen plannus and B, C hepatitis. Two cyrotic patients from among 23 were with LP, which statistically was significant (P<0.05). All patients with LP should be tested for B, C hepatitis and liver enzymes.

Statement of Problem: Candidal colonies make up a part of natural oral flora and are considered as predisposing factors for opportunistic infections. Since hemodialysis leads to body Immune suppression and make patients susceptible to opportunistic infections, it is useful to investigate the relationship between hemodialysis and such infections. The aim of the present research was to study the relationship between oral candidal colony count and duration of hemodialysis and also to investigate the probable necessity for prophylaxis against oral candidiasis. Factors such as oral temperature, age, sex, denture, smoking, drugs, candidal microscopic view and clinical signs of oral infections, were also studied in relation to candidal colonies. The smear of posterior part of tongue and oral fluids from 114 hemodialysis patients in Khorshid hospital, Isfahan University of medical Sciences were cultured. The number of oral candidal colonies and their microscopic view were studied in relation to the duration of hemodialysis and other factors. To analyze the data, Pearson and Spearman statistical tests were used. No statistical significant relationship was observed between oral candidal colony count and the duration of hemodialysis. Due to the abundant predisposing factors for oral candidal infection, the probability of oral candidiasis cannot be predicted based on a single factor, namely duration of hemodialysis. As a result,according to this study, the prophylactic prescription of antifungal drugs are not suggested in hemodialysis patients. However, the results of the present study should not be over generalized and more studies are required.

Statement of Problem: The role of the microbial plaque in caries etiology and periodontal diseases has been proved and the mechanical methods for plaque control have special limitations, consequently, chemical methods have been suggested. One of the most effective materials is Chlorhexidine Gluconate that is commonly used as mouth rinses. However, the medicated formulations of chewing gums, due to several properties, have been paid attention. It should be noted that a new formulation to satisfy the consumer's taste seems necessary. The aim of this study was to present a new formulation for chewing gums containing chlorhexidine to achieve a pleasant taste coupled with their effectiveness and anti-plaque properties maintenance. In this double blind, crossover, prospective clinical trial, 18 volunteers were investigated. Chlorhexidine Gluconate was used and added to the gum-base by Manitole. In order to cover the bitter taste of the drug Aspartam, mint essence and Mentole were used. After gums production, the profile of drug dissolution was evaluated by jaw movement simulating system. It took 5 days to study each type of chewing gums without any mechanical plaque control method. Medicated and placebo chewing gums were identical in shape, size, color and formulation. The washout period was 2 days. Chewing gums were used every 12 hours for 20 minutes. To determine plaque score, Turesky- Gilmore- Glickman modification index was used. Other variables including: subjective evaluation of taste, cleansing effect and taste disturbance were assessed through filling a checklist. The data were analyzed by Paired t test and Wilcoxon test. During 20 mins, 80% of the drug was released from the gum-base. The mean difference of plaque score between the initial and final stages at the first trial was -0.1589 and at the second trial was 2.994 which was statistically significant (P<0.001). Subjective evaluation of cleansing effect showed statistically significant differences between the placebo and medicated chewing gum (PO.00I). There was no statistical significant difference between the subjective evaluations of taste (P-0.157). No taste disturbances were reported. In this investigation, the researchers could for the first time introduce new formulation for chlorhexidine medicated chewing gums with efficacy and anti-plaque effects coupled with an acceptable taste for public usage.

Statement of Problem: The goal of bone regenerative therapy is to reconstruct the damaged tissues to initial condition, which seems so important in periodontoiogy and implantology. In such therapies, different biomaterials, with some advantages and disadvantages, may by use. The aim of this research was to evaluate the quality, bone trabecular density and thickness of newly forming bone as well as foreign body reaction against Biostite®, in comparison with the control group. In this experimental study the total number of 5 sheep was operated with general anesthesia. At first 10 standard defects were created in 5x5x5mm on the left and right edentulous mandibular ridge. Five defects were randomly treated by Biostite®, the remaining five were considered as controls. After six months, the sheep were sacrificed and the separated defect areas with intact marginwere placed in 10% formaline and prepared for histologic and histomorphometric study. To analyze the data, Mann-Whitney U test was used. The mean percentage of new bone formation in Biostite® group was statistically more than the control group (PO.05). Newly formed bone was vital in both groups which was a combination of lamellar and woven types, however, the thickness and density of new bone in biostite® group was more than the controls. Foreign body reaction was observed in Biostite® group. It is suggested that Biostite® synthetic material can be useful in bone regenerative therapies.

Statement of Problem: Rotary dental instruments (i-e. iow speed and high speed handpieces), due to infection spread high potentiality, should be sterilized between dental visits for each patient. When a high speed rotary instrument pauses at a high velocity, contaminated fluids like blood and saliva will be sucked into its tubes. The aim of this study was to compare the bactericidal effects ofDeconex 53 plus solution and the solarsept spray on dental high- speed instruments. In this experimental study, one hundred and twenty (120) dental high- speed turbines, sterilized by autoclave, were divided into 6 groups. The turbines were contaminated with bacterial suspension. Streptococcus mutans, Staphilococcus aureus and Neisseria SP were the first microbial groups. Pseudomonas aruginosa was the second microbial group and Bacillus subtilis sporewas the third microbial group. After 5 minutes, three contaminated groups were placed in Deconex53 plus 2% solution for 15 minutes. Three other groups after contamination were sprayed with Deconex soiar sept spray for 2 minutes. Then the samples were placed in TSB culture and after 24 hours incubation at 37°, the samples were transmitted on blood agar solid culture for bacterial viability observation. The results were observed after 24 hours incubation. Proportional test with normal distribution was used for data analysis. The Deconex 53 plus had 85% disinfectant activity on the first microbial group, 10% on the second microbial group and 100% on the third microbial group. Also the solarsept spray had 30% disinfectant activity on the first microbial group and 15% on the third micribial group. The solarsept spray had no bactericidal effect on turbines contaminated by the second microbial group. The results proved that the disinfectant effects of Deconex 53 plus solution for 15 minutes were significantly better than the solarsept spray for 10 minutes. The Deconex solution and the solarsept spray showed 65% and 15% negative growth, respectively. Based on the elimination of all spores, Deconex 53 plus has great sporcidal activity. These disinfectants should not be considered as suitable substitutes for sterilization with autoclave.

Statement of Problem: Changes in protein levels, host calls enzymes and inflammatory mediators in gingival crevicular Fluid (GCF) are considered as diagnostic indicators of Periodontitis. he aim of the present study was to measure the elastase enzyme activity in gingival crevicular Fluid among patients with periodontitis. In this study, 52 periodontitis patients (experimental group) and 51 healthy subjects without any gingival inflammatio (control group) were participated. Subjects of the periodontitis group showed pockets of 4-5 mm depth without gingival enlargement and recession or pockets of 1-2 mm depth with gingival recession. For enzyme activity measurement, lOOu,! of gingival fluid of each sample was mixed with lOOu! of enzyme substrate on the tube. The mixture was incubated at 34°c for lh with a buffer solution of 1ml volume and absorbance was read at 410nm with spectrophotometer. The enzyme activity differences between two groups were analyzed by student t test. The elastase enzyme activity in gingival crevicular fluid in subjects with periodontium destruction and control subjects was 153±11.3 and 52.7±10.4 enzyme unit in ml per minute, respectively. The difference between groups was statistically significant (PO.05). Based on the findings of this study, the measurement of elastae enzyme activity could be a useful indication of tissue changes that may ultimately manifest clinically as periodontitis.

Distraction osteogenesis (DO), firstly introduced to the medical world by Russian scientist Ilizarov for long bone lenghtening in orthopedics can be considered as an appropriate substitute in the treatment of maxillofacial deformities. Natural events occuring during the repair of a fractured bone segment not only lead to the desired bone length but also prevent from the undesired disadvantages of osteotomies and bone grafting. Recently a lot of investigations have been conducted to evaluate the efficacy of DO in the treatment of maxillofacial deformities, which in some cases have lead to successful results. In the present article a lot of issues in maxillofacial surgery and different treatment goals associated with DO are discussed.