مجله تحقیق در علوم دندانپزشکی
سال دهم شماره 4 (پیاپی 38، زمستان 1392)

Chlorhexidine (CHX) is recognized as the most effective agent in plaque control. Some of these mouth rinses contain alcohol، making them impractical for many patients due to oral mucosal hypersensitivity. Although fewer side effects may be seen in alcohol free mouth rinses، they may turn out to be less efficient in terms of anti-plaque activity. The aim of this study was to evaluate the efficacy of a 0. 12% chlorhexidine mouthrinse with and without alcohol compared to 0. 2% alcohol containing CHX. Sixteen volunteers participated in this randomized clinical، single blind، cross over study to assess the anti-plaque efficacy of 0-2%CHX mouth rinse containing alcohol compared to two 0. 12% CHX mouth rinses with and without alcohol and normal saline (negative control). After oral prophylaxis، subjects were asked to abstain from all forms of oral hygiene measures and wash their mouth only with allocated mouthrinses twice a day for four days. Between each period of mouthrinsing a 10-day washout period was scheduled.. Data was collected and analyzed using Kruskall-Wallis and Fischer exact tests. All three mouthrinses demonstrated statistically significant reduction in plaque score compared to normal saline (P<0. 001). However، no significant difference was found in efficacy of alcohol-free and alcohol containing mouth rinses (P< 0. 02) It seems using 0. 12% CHX without alcohol has similar anti-plaque effects compared to alcohol containing CHX and may be prescribed in hypersensitive patients.

The aim of the present study was to assess the effect of mandibular inclination on accuracy of linear measurements performed on CBCT scans. In this descriptive analytical study، 12 linear dimensions between anatomical landmarks were measured on a dried human mandible. The measurements were obtained with a digital caliper three times by two observers. The mandible was scanned using a cone-beam CT (scanora 3D) with the base of mandible positioned in 5 different inclinations: horizontal، tilted downwards، tilted upwards، laterally tilted and rotated. Computer measurements of the dimensions were obtained twice by two observers، three times at each session. Then، the inclinations were corrected by the software and all the measurements were repeated. Paired T-test and Pearson correlation test were used to analyze the data. In 88. 4% of the samples، the mean computer measurements were smaller than the mean manual caliper measurements. The mean difference was 0. 01-2. 65 mm for different inclinations. The percentage error was below 10% (except for 6 cases) which is considered to be the safe margin in studies. Following correction of the inclinations، the mean absolute error exceeding 1 mm was observed in only one case and the percentage error was less than 8%. Regarding the reproducibility high inter and intra examiner correlation was observed (r>0. 9). High inter and intra examiner correlation was observed with respect to the reproducibility of the results (r>0. 9). Head orientation during CBCT scanning is not as crucial as in CT scan especially when the inclinations are corrected via software before the measurements.

Reports are indicative of effective treatment of oral diseases by traditional medicine including SUAB2 solution. The purpose of this study was to assess the effect of SUAB2 impregnated dental floss on periodontal indices in patients with gingivitis. This randomized، split mouth، double blind clinical trial was performed on 10 patients with gingivitis. All patients underwent scaling and Oral Hygiene Instructions. Baseline Plaque Index (PI)، Bleeding on Probing (BOP)، Gingival Index (GI) and Pocket Dept (PD) were assessed and recorded. Regular dental floss (placebo) and dental floss impregnated with SUAB2 were submitted blindly to the examiner. The upper right and lower left quadrants were selected for assessment in group A and the lower right and upper right quadrants were selected for assessment in group B. The patients were also blindly trained to use dental floss A and B in the selected quadrants after brushing. The patients were recalled after 1. 5 and 3 months and all indices were re-assessed. Statistical analysis was done by Mann-U- Whitney، McNemar’s، and paired t-tests. The study was conducted on 10 patients (20 samples). The reduction in PI، BOP and PD was statistically significant in the SUAB2 floss group after 1. 5 month (p<0. 05). However، there was no significant difference between the two groups in 3-month follow up (p<0/4). The GI differences between two groups were not statistically significant in 1. 5 and 3-month follow up (p<0. 2). SUAB2 impregnated dental floss has a significant role in reduction of PI، BOP and PD

Enterococcus faecails has been realized to have a key role in post endodontic infections. Treatment strategies designed to eliminate this microflora should include agents that can effectively disinfect the root canal. The purpose of this study was to evaluate the anti-microbial effect of different concentrations of Ledermix and a new medicament on Enterococcus faecails. In this experimental in vitro study، E. faecails was inoculated to BHI (Brain Heart Infusion) broth and incubated at 37º C for 24 hours. The cell suspension of E. faecalis was then spread on to a blood agar plate and was incubated overnight at 37ºC for 24 hours. One colony of microorganism was inoculated to TSB media and incubated overnight at 37º. One hundred microliters of the suspension was spread thoroughly onto a Moller Hinton Agar. Thirty Prepared disks with in different concentrations were fixed on to plates and incubated overnight at 37º C. The latest loop culture that did not show any growth was considered as MIC. and any concentrations of MIC that didn''t show growth on agar plates was considered as MBC. The results were analyzed using one way analysis of variance (ANOVA). The average inhibition zone for bacterial growth was measured to be 2. 56±0/20cm for ledermix in concentration of 1gr/lit، and 2±0/30cm in concentration of 0. 5g/lit. The inhibition zone measurement was 1/53±0/40cm for new formulation medicament in concentration of 1 gr/lit. The difference was statistically significant (p<0. 05). MIC effect of ledermix revealed in in concentration of 0. 5 gr/lit and for new formulation medicament was in concentration of 1gr/lit. Both compounds display similar anti-microbial effects. However، Ledermix prepared at higher concentrations appears to have a greater inhibitory effect on growth of E. Faecalis.

Postoperative swelling and edema can cause distress to the patient due to considerable pain and، delayed healing. The purpose of this study was to evaluate the effect of sub mucosal injection of Dexamethasone on postoperative edema after BSSRO. The study design was double blind clinical trial in which 19 patients requiring BSSRO were informed and randomly placed into two groups، 11 patients in the case group received 8mg Dexamethasone as a submucosal injection and 9 patients in the control group received 8mg of intravenous injections. Standardized surgical protocols were performed by the same surgeon. Maximum distances from the tragus to the corner of the mouth and from the tragus to the pogonion were measured at baseline and 48 hours post-surgery. Statistical analysis was done using Mann-U-Whitney Test. The study was done on 19 patients in two groups that were matched based on age، sex، weight، period of surgery، type and level of malocclusion and socio-economical state. The average distance from the tragus to the corner of the mouth was 12. 8±3 in control group and 14. 6±14. 9 in case group (p<0. 8). The average distance from the tragus to the pogonion was 10. 5±3. 2 in control group and 14. 2±4. 3 in case group (p<0. 2). Submucosal injection of Dexamethasone is as effective as intravenous injection in reduction of post-operative edema after BSSRO.

The purpose of this study was to analyze the components of waste products generated at dental centers. In this study، 37 dental centers were studied in 9 regions which were selected using regional sampling pattern. Each of the three waste samples at the end of three consecutive working days (Monday، Tuesday and Wednesday each week) were analyzed. Samples were separated manually and weighed and divided into 64 different components. Measured components were categorized based on the characteristics and potential hazards. The Excel software was used for data and statistical analysis. The total amount of waste generated per year in dental offices was 62661. 60 kg. The volumes of generated infectious، domestic، pharmaceutical، and poisonous chemical waste products were 50. 50%، 39. 04%، 9. 55%، and 0. 91% respectively. These findings were similar to the results of other researches conducted prior to this study. Understanding the components of dental waste materials is essential for proper waste management including collection، processing، transport، and disposal of hazardous products.

Lichen Planus is a relatively common mucocutaneous disease which usually affects the oral mucosa. Patients with Oral Lichen Planus (OLP) suffer from symptoms that affect different aspects of their daily life. Although the exact etiology of OLP is unclear، the role of psychological disorders especially stress، anxiety and depression is debated. The aim of this study was to analyze mental health and oral health related quality of life in patients with OLP. In this case-control study، 35 patients with OLP along with 50 healthy people matched by age، sex and oral health level were involved. Both groups completed the GHQ-28 and OHIP-14 questionnaires. Oral examination was also performed. At the end، data were analyzed by SPSS v. 18 software and Descriptive statistics، Chi Square Test، T-test and Mann-U- Whitney Test. There were statistically significant differences in the functional limitation and physical disability aspects of OHIP-14 in patients with OLP in comparison with the normal group (P =0/02(P= 0/03) respectively. Besides، there were no significant differences between the groups with respect to psychological disorders. (P = 0/41) The quality of life in patients with OLP is reduced in some aspects. Moreover، our findings do not support a relation between OLP and psychological disorders.

Artifacts refer to the artificial structures on microscopic slides which may lead to an incorrect tissue diagnosis.، The present study was conducted with the aim to investigate the frequency and type of artifacts found in histopathology slides. In this descriptive study، 154 slides were randomly selected from the archives (2008 to 2012) and their clinical data were extracted from the records. Slides were evaluated by an oral pathologist in terms of the presence or absence of artifacts. Using the reference book، artifacts were categorized into three groups which included those caused by surgeon’s performance، technician’s performance and method of transport to the laboratory. The frequency and type of artifacts were presented as the percent. Out of 154 slides examined، only one case (0. 06%) was free of artifact; 91. 6%، 99. 4% and 0. 06% of slides were respectively found with artifacts caused by the surgeon’s and the technician′s performance and mode of transport to the laboratory. The highest and lowest numbers of artifacts relating to the technician′s performance were due to formalin sedimentation and contamination factors respectively. The highest and lowest numbers of artifacts caused by the surgeon’s performance were associated with crack and heat factors respectively. The high frequency of artifacts in microscopic slides indicates an absolute need for competent performance and efficient cooperation of surgeons، pathologists and laboratory technicians in order to achieve better diagnostic results and diminish the rate of artifacts in histopathology slides.

Human dental pulp stem cells have substantial proliferative and differentiation potential. The isolated stem cells or progenitor cells of the pulp can differentiate into odontoblasts or /and osteoblast-like cells and aid in repair as well as reconstruction of tooth structure. Several ways have been introduced for isolation and tracing of these cells. The aim of this study was to isolate mesenchymal stem cells from deciduous dental pulps as well as labeling them with Technetium (Tc99m) to investigate the effect of Tc labeling on the survival rate of stem cells. In this experimental study، exfoliated deciduous teeth of 6-11 year old children without any history of systemic disease were collected. Enzymatic and non-enzymatic methods were used to expedite cell isolation and isolated cells (10000) from dental pulp were mixed with 25 millicurie of Tc for tracing purposes. Individual cell activity as well as culture medium activation was evaluated separately afterwards. Data was analyzed using ANOVA statistical test. Isolated dental pulp cells formed single cell derived colonies which showed fibroblast-like growth with solo cloning morphology. Specific staining of the cells indicated them to be stem cells and confirmed their differentiation into bone and fat. Moreover، Technetium significantly decreased the activity of cells. The survival rates of the cells in the period of 1،3،6،24،48 hours were reported to be 95. 5%، 85. 5%، 77. 4%، 68. 4%، and 57. 3% respectively. The dental pulp stem cells have a significant capacity to differentiate into bone and fat. Tracing the cells with Tc M99 will reduce their survival rate over time.

Clear cell odontogenic carcinoma (CCOC) is a rare aggressive odontogenic tumor occurring mostly in the mandible in 5th–7th decades. It shows a female preponderance، capable of frequent recurrences and loco-regional and distant metastases. A 40 -year-old man with swelling in the area of left mandibular body and ascending ramus visited a dentist، and the patient''s third molar was extracted with initial diagnosis of infection and abscess. Following extraction of the third Molar، the patient was referred to the oral and maxillofacial surgeon for continuous swelling and pain. In the panoramic view a multilocular radiolucent panoramic view a a multilocular radiolucent lesion with well-defined and partially corticated borders was evident. The lesion was removed partially and CCOC histopathologic features were observed in the microscopic view. Immunohistochemically، the tumor cells were positive for Pancytokeratin and Epithelial Membrane Antigen and negative for Vimentin، Smooth Musle Actin، HMB-45 and Desmin. S-100 staining was weakly positive. The patient did not return for further treatment and one year later there was no recurrence of swelling in the region. Due to histological similarities of this lesion with other clear cell lesions، differentiation From odontogenic tumors، salivary gland tumors and metastatic tumors، containing clear cells must be considered.