Journal of Mashhad Dental School
Year:2007 | Volume:31 | Issue:1-2|Papers Count:23

Introduction: Dentigerous cyst (DC) is the most common pathologic pericoronal radiolucency and the odontogenic keratocyst (OKC) radiographic features appear as unilocular, multilocular or pericoronal radiolucency. Since OKC is very invasive and has a high recurrence rate and its radiographic features are like dentigerous cyst and bone important lesions such as amelobastoma and mural ameloblastoma, it seems necessary to recognize radiographic features of these two cysts.The aim of this study was to compare panoramic radiographic findings in DC and OKC. Materials & Methods: In this descriptive (case series) study, 41 panoramic radiographs of 26 patients with DC and 15 patients with OKC, were evaluated by one maxillofacial radiologist as an observer.The radiographic information included persent pericoronal radiolucency , unilocular or multilocular radiolucency, smooth or scalloped periphery, impacted tooth, size and area of cyst, age and sex. Finally, the data were analyzed using Chi-square and T tests statistically. Results: one case of DC had multiolocular radiolucency, 4 cases of OKC had unilocular pericoronal, 2 cases had multilocular pericoronal, 2 cases had unilocular non-pericoronal radiolucency and 7 cases had non-pericoronal multilocular radiolucency. A significant relationship was detected among the mean age of patients, and mean area of cysts (P<0.05).Conclusion: Based on the present study, DC was more common in maxillary canine appearing mainly as a pericoronal unilocular pattern, while OKC was more common in mandible appearing mainly as a multilocular pattern.

Introduction: Ostetoblasts and ligament periodontal cells are the essential cells for wound repair after root-end resections and perforation repair. Osteoblast cells reaction in direct contact with filling materials play a critical role in wound repair after surgeries and perforation corrections. Cell attachment on material surfaces and cell secretory function is the primary phase for evaluation of normal cell function. The aim of this study was to morphologically evaluate osteoblast cells (MG-63) function and IL-1β secretory level adjacent to gray MTA, white MTA, Portland cement and IRM, as materials for root-end fillings and repairing perforations. Materials & Methods: Human osteoblast cells (MG-63) obtained from Iran Pasteur Institue. cell bank were grown in RPMI-1640 medium. The under study materials, following the company instructions, were mixed and seeded in 24, 1cmx1cm partition plates with the aproximate thickness of 1mm. The cells were added after the materials primary setting time. The cells were observed by a light microscope an day 1, 3 and 7. In the mentioned intervals, the cells supernants were collected and examined by ELISA and the amount of IL-1β in each specimen was measured in pg/ml. The turkey test was used for comparison of the data among different matreials and the Komogrov-Smirnov test was used for normalizing the resonses. Results: The cells morphological outcomes illustrated that after 7 days, a large amount of osteoblasts adjacent to gray and white MTA had the good attachment and morpholigically expansion and flat. The cells adjacent to Portland cement were found round and mostly seperated from the surface, although some flat cells could be found among them. Adjacent to IRM, all the cells were round and seperated from the plate surface. The level amount of IL-1β secretion adjacent to gray and white MTA was significantly more than to IRM and Portland cement (P=0.00). Adjacent to gray and white MTA, the amount of IL-1β secretion was not significantly different (P=0.77), also the IL-1β secretion level adjacent to Portland cement and IRM was not significantly different (P=0.187).Conclusion: The currrent study result indicates that human osteoblasts adjacent to gray MTA and white MTA, in comparison to Portland cement and IRM, showed a more appropriate response. Therefore we recommed the use of MTA over the other materials. Regarding Portland cement more research needs to be done in order to reach a final conclusion.

Introduction: Successful root canal therapy is related to cleaning, shaping and obturation of the root canal system with a proper limited working length. Therefore, these are achieved by knowledge of root canal anatomy and radiograph images. Current radiographic techniques are elementory methods. With the advancement of computer technology, and due to limitations that exist, in this recent decade significant attention has been given to digital radiography. Software programs for digital radiographic systems, such as magnification of different images is a tool assistant for digital systems in increasing precision. The purpose of this study was to compare different magnifications of digital radiography to determining canal length. Materials & Methods: In this experimental in vitro study, 30 human anterior teeth were selected and cleaned in detergent. The actual working length was measured with a N.15 file. Then the teeth were casted and the files were inserted in canals in 3 different positions, proper, under and over. Ninety images of the teeth in three magnifications were made and working length was evaluated by three endodontists randomly. Then the Friedman test was used for statistical analysis. Results: After statistical analysis, the results showed that there was no significant differences between the groups. But there is significant difference in 2X magnificantion of under working length to real working length.Conclusion: In conclusion, it can be stated that magnification of digital radiography can not be helpful in determination of working length especially in under postion

Introduction: Congenital heart disease (CHD) can have oral manifestations that even the patient may not be aware of. These manifestations could be linked to the disease itself or the treatment associated with it. Also, since a history of CHD may alter the treatment plan of some of the oral diseases or some oral diseases may affect the course of CHD, the current research was designed to better understand such interrelationships. Materials & Methods: In this cross-sectional descriptive study, 42 CHD patients that were admitted to the department of Internal Medicine of Imam Reza Hospital, Mashhad, Iran, were randomly investigated for a period of one year through a questionnaire and routine examinations and the final results are descriptively presented. Results: In 17 cases (40.5%), cyanotic mucosa was reported and in 6 cases (14.4%) pale tissues were noted. In 2 cases cleft palate (4.7%) and cleft lips (4.7%) were recorded. Conclusion: Oral manifestations recorded for patients with CHD were Cyanosis, pale tissues and cleft and palatte and lip. Although clefting and palate lip can not be directly linked to CHD, their presence in conjunction with CHD should be considered.

Introduction: Tooth whitening products may have effects on various properties of restorative materials including hardness. This study investigated the effects of two at-home bleaching agents (Kimia 16%, Opalescence PF 15%) on hardness of a microhybrid composite. Materials & Methods: Thirty cylindrical-shaped specimens of microhybrid composite Z250 (3M, Dental Products, USA) with 5mm diameter and 2mm height  were prepared and divided into three treatment groups comprising a control and two different bleaching groups. Control specimens were stored in distilled water for two weeks. Specimens of bleaching groups were exposed to the bleaching agents (Kimia 16% the first bleaching group and opalescence 15% for the second group) 1 hour daily for 2 weeks. After treatment, the hardness of specimens was tested using Vickers-test Instrument under 300 gr load for 15 seconds. The data were analyzed using One-way ANOVA and Tukey tests (α=0.05). Results: The mean composite microhardness for control, Kimia and Opalescence groups were 97.93±4.59, 95.56±2.75 and 86.57±2.59 respectively. It was observed that the bleaching materials softened the composite Z250. However, ANOVA showed the difference between Kimia group and control group was not significant (P=0.280)). Hardness of Opalescence group was significantly lower than the two other groups (P=0.000).Conclusion: Regarding the decreased microhardness of microhybrid composite, Kimia 16% at-home bleaching agent is more desirable than Opalescence PF 15%.

Introduction: In contemporay orthodontics, the number of people who demand orthodontic treatment for improving their psychosocial problems retated to facial esthetic has been increased. Even in treatment planning more attention has been give to appearance and esthetic. The purpose of this study was to determin relationship between orthodontic treatment required according to the Dental Aesthetic Index (DAI) and student’s perception in 11-14 year- olds in Ahwaz. Materials & Methods: This decriptive cross sectional study was performed on 900 students (450 girls, 450 boys). The students that participated in this study were those who did not received any orthodontic treatment before or at the time of the study. Two questionnaires were used, the first one included different DAI criteria and second one included some questions about the students' perception on the appearance of their teeth. The results were analyzed by Chi-Square test and T-test. Results: In 70.9% students DAI score was 13-25, which indicates no treatment to minimal treatment is necessary. In 19.2% students DAI score was 26-30 which presented definite malocclusion with optional treatment. In 7.8% students DAI score was 31-35 that which showed sever malocclusion with treatment highly desirable. In 2.1% students, the DAI score was greater than 35 which showed very sever malocclusion and treatment is mandatory. The relationship between the DAI Score and sex, chewing and talking were not statistically significant. But the relationship between the DAI score and orthodontic treatment need and satisfaction of dental appearance were significant (P=0.000). Conclusion: In comparison to other studies, the students in Ahwaz had a better dental appearance and minimal need for orthodontic treatment. A significant relationship exists between the need for orthodontic treatment and student’s perception (P=0.000). In comparing the two sexes, boys had a greater need for orthodontic treatment, but is not statistically significant.The relationship of the DAI score and a person's satisfaction of dental appearance, anxiety in laughing, person's appearance in relation to other students and being ridiculed were significant (P=0.000).

Introduction: Developed synthetic resin cement are recommended for cementation of crown and bridges. Bonding of adhensive resins to ceramic, metal, enamel and dentin is an important factor for a successful clinical restoration. The purpose of this study was to determine the shear bond strength of 3 luting cement systems (Dual cure, self Cure and resin modified glass inomer) for bonding the base metal alloy, Ceramco and Inceram porcelain to dentin. Materials & Methods: In this experimental study, 90 extracted human teeth were prepared and buried in self cure acrylic resin while the buccal surface remained out of the acrylic material. The enamel of the buccal surface were removed and a flat surface was obtained on the dentin. Thirty blocks of base metal alloy, Ceramco laminate porcelain and Inceram were prepared with the dimensions of 6x4x2mm, and divided into 3 subgroups. Each subgroup was cemented with C & B Metabond, Panavia F and Rely X to dentin. After that, they were thermocycled between 5oc to 50oc for 500 cycles, the shear bond strengths were measured in an universal testing machine.  Finally, the specimens were inspected under a stereomicroscope with a magnification of 40 to determine the modes of failure. The data were analysed using SPSS software (2-way ANOVA, Duncan's test and Fisher's Exact test). Results: Maximum shear bond strength in bonding of 3 experimental plates to dentin with 3 adhesive resin systems are as follows: Panavia F for base metal plates (15.316±2.925 MPa), C&B Metabond for Ceramco porcelains (11.789±1.730 MPa) and Inceram porcelains (10.512±3.249 MPa).Conclusion: Within the limitation of this study, the best cement for cementation of base metal  plates was Panavia F or C & B Metabond cement. Among these three evaluated cements,C&B Metabond cement proved to be better for cementation of Ceramco porcelains to dentin and C&B Metabond or Panavia F for cementation of Inceram plates to dentin.

Introduction:  Surgery is one treatment modality for periodontal diseases that can stimulates osteoclastic activity and results in resorption of alveolar crestal bone. The aim of this study was to compare the effect of two procedures of periodontol surgery on resorption of alveolar crestal bone. Materials & Methods: Twenty patients were selected from patients referred to our dental school. After initial therapy, the surgical treatments were performed by a surgeon and the study was performed with split mouth design. One side was treated with an apically positioned flap (APF) with bone exposure (20 quadrants) and on the opposite side APF without bone exposure (20 quadrants). At the time of surgery the distance between CEJ to bone crest was recorded. After two months, the patients were examined for the same parameters using the bone sounding technique. Results: According to the results, in sites with apically positioned flap with bone exposure, crestal resorption was 0.77±0.63 and on the opposite side it was 1.05±0.79 mm. The difference between the two sides was not significant. Pocket changes were significant in both techniques but there was not any significant differences between the two procedures.Conclusion: According to the results of this study, similar alveolar crestal bone resorption occurred during the healing process in the two procedures and this resorption may have an important role in reconstruction of biologic width.

Introduction: Color matching, visual combination and accurate shade selection with natural teeth are important issues in restorative dentistry. In ceramometal restorations, the type of substructure alloy affects the final color of bonded porcelain. Minalux alloy, is the most commonly used Iranian product which is a base metal alloy (Ni-Cr). The aim of this study is to compare the effect of three base metal alloys (Wirron 99, Bellabond and Minalux) on their masking of porcelain color and to assess various color dimentions between them. Material & Methods: In this in vitro study, ten disks, approximately 0.3 mm thick and 1 cm diameter, were prepared from each alloy. Then a 1 mm thickness layer of vita VMK68 porcelain shade A2 was baked onto them, following the manufacture's instruction. Ten samples with 5 mm thickness were prepared from the same porcelain and designated the "control group". All samples, with similartining and in similar conditions of environmental light were assessed by a computer colorimetry instrument; and color values such as l*, a* and b* under CLE-LAB system were measured. The data were analyzed by one-way-Anova and Tukey tests. Results: Three alloys in this study as compared with the control group, had significant effect on the three variables l*, a* and b* (respectively P=0.004, P=0.037, P<0.001). In these alloys, Wirron 99 and Bellabond, had significant difference on the two variables l* (P-value=0.025) and a* (P-value=0.037); but Minalux alloy did not have any significant difference with other groups. The comparison between the average of ΔE quantities alloys, indicated that the difference of Vita porcelain shade A2 baked on Wirron 99 and Bellabond was significant.Conclusion: The effect of Iranian minalux alloy on color's parts and it's related ΔE quantity, is in a similar range of two foreign alloy products Wirron 99 and Bellabond.

Introduction: Orofacial clefts are the most common congenital clefts in humans. Etiology of oral clefts is multifactorial (genetic and environmental factors) and prevalence of oral clefts is different among various ethnic groups. The aim of this study was to determine the frequency of oral clefts and risk factors related to it among a group of newborns in Iran. Materials & Methods: This descriptive study was performed on 147500 files of newborns (1994-2002) in Mahdieh and Akbarabady Hospital in Tehran. The files of 193 files of newborns with oral clefts, 240 normal newborns as control group and their mothers were evaluated. Demographic data along with information about (sex, weight, prematurity, type of oral clefts) of newborns and age, drug consumption and familial matrimony of mothers were recorded. Data were analized by SPSS 10 software and the Chi-square test. Results: Out of totally 147500 newborns 193 cases had oral clefts (1.3 for 1000 brirth), 46.11% had cleft lip+cleft palate), 29.01% had (cleft lip) and 24.87% had cleft palate). Male to female ratio was 1.27. Oral clefts were significantly higher in low weight newborns (<2500 gr) (P<0.001, OR= 3.2). A significant relationship was found between familial matrimony of parents (P<0.001, OR=27), age of mother and systemic disease the mother and organic disorders. (P=0.04, OR=2.6, OR=2.3) with oral cleft in new borns. In 50% of newborns with cleft palate had other skeletal.Conclusion: The present study showed that frequency of oral clefts in the studied population was 1.3 for 1000 births, which is similar to other research results in Iran. On the base of this study low birth weight of newborns (<2500 gr), familial matrimony of parents, age of mother and systemic disease of her and large size family are the most predisposing factors associated with oral clefts, respectively A prenatal care program for pregnant women and genetic consultation in high risk groups is recomended.

Introduction: Dentinal hypersensitivity is one of the most common complications which many patients complain in different ways. Dentinal hypersensitivity is caused by the opening of dentinal tubules to an oral cavity due to fractures, attritions, etc. It is a common complications after periodontal surgery. Many treatments have been suggested for this problem, till now. Calcium hydroxide is one of the materials used for treatment of root hypersensitivity after periodontal surgery. The aim of this study was to evaluate the effect of calcium hydroxide combined with periodontal dressing on root hypersensitivity after periodontal surgery. Materials & Methods: This study was done on 30 patients with severe periodontitis who needed periodontal surgery for both quadrants in each jaw. In each patient one quadrant was treated as a test and the other side was used as a control. In the test group 90mg of Calcium Hydrixude powder mixed with 1cm of Co-pack covered the site surgical. Twenty-one patients completed the procedure After surgery, a periodontal dressing combined with calcium hydroxide covered the area  on the test side. The other side was used as a control and covered with a pure dressing. After one week the dressing was removed and the amount of hypersensitivity was measured with air flow and an explorer using the visual analog scale. Data were analyzed using the Wilcoxon sign rank test. Results: The results showed that there were not any significant differences between the two sides in root sensitivity, but Plaque index in the test sides was lower than the control side. Conclusion: The periodontal dressing can not be used as a carrier for calcium hydroxide to reduce root hypersensitivity after periodontal surgery. Decrease in plaque accumulation after using the combination of calcium hydroxide and periodontal dressing may accelerate surgical wound healing but further investigations are necessary.

Introduction: Complete root canal seal is one of the most important aims of root canal treatment. For this purpose, elimination of the smear layer and the kind of sealer used have important roles. The aim of this study was to compare the sealing ability of two sealers (ZOE and resin based) against the microleakage of entrococcus faecalis when used in association with three different root canal irrigants (17% EDTA, 7% citric acid, 20% citric acid). Materials & Methods: In this experimental study, 170 single - rooted extracted human teeth were selected. Step back canal preparation was performed to Iso size No. 40 in the apical portion of the canals with 5.25% Naocl irrigation. The teeth were randomly divided into 8 groups: six experimental groups of 25 teeth and two control groups of 10 teeth. Final irrigation in groups 1 and 2 was preformed with EDTA+NaClO; in groups 3 and 4 with 7% citric acid+NaClO; and in groups 5 and 6 with 20% citric acid+NaClO. Groups 1, 3 & 5 were obturated with guttapercha and AH26 sealer, and groups 2, 4 & 6 with guttapercha and Tubliseal sealer using lateral condensation. The 10 positive control teeth were obturated with a single guttapercha cone and the 10 negative control teeth were thoroughly obturated with gutta-percha and sealer. After 48 hours in 100% humidity and 37ºc temperature, the roots were assembled in the designed system for this experiment. A fresh solution of entrococus faecalis was injected to the system every 3 days. The samples were evaluated daily for 160 days and the time of culture contamination with E. faecalis was registerd in each case. ANOVA and Duncan tests were used to analyze the results. Results: All the samples in positive control group were infected after 24 hours. None of the negative control samples were infected after 160 days. Group 1 (EDTA+AH26) and group 3 (7 %citric acid+AH26) had no significant difference with group 2 (EDTA+Tubliseal) and group 5 (20% citric acid+AH26), but group 2 and 5 were significantly different (P<0.001). Group 4 (7% citric acid+Tubliseal) was not significantly different from group 6 (20% citric acid+Tubliseal) but they both were significantly different from the other four groups (P<0.001).Conclusion: In this study 20% citric acid used in association with AH26 showed the greatest microleakage mean time. The least microleakage mean time occurred in the group for which 20% citric acid was used in association with Tubliseal

Introduction: Candida albicans is colonized on different oral surfaces such as tongue, palate, dental caries and plaques. Different factors like age, sex, diet, dietary habits and oral hygiene play role in amount and severity of colonization of this microorganism. Our goal was to determine the relationship between the existence of Candida albicans in oral cavities and dental caries in students of dentistry. Materials & Methods: This descriptive-analytical study was performed on 121 students of Babol dental school without any history of systemic disease and use of antibiotics or streoidal drugs. After explaining study goals and getting informed consent, the students' demographic information and medical histories were recorded in data sheets. Then clinical examination for determination of DMFT and plaque index was done. Salivary PH was measured. Dental plaque samples were cultured. Data were analysed by SPSS 10.5 using Student t-test, Fisher's Exact test, Mann-Whitney U test and Chi-Square test. Results: 63 (52.1%) students were male and 58 (47.9%) female. The mean age was 24.61±5.2 years. Candida culture was  positive in 53 (43.8%) salivary and 51 (42.1%) plaque samples which in 50(94.3%) of salivary and 45 (88.3%) of plaque cultures was Candida Albicans. 44 students (36.4%) were caries free. The positive Candida cultures were more common in  students with more dental caries, less than 7 restorations, oral PH<7, and moderate dental plaque (P<0.05). It was also more common among smoker students. Presence of Candida Alicans in saliva and plaque samples had no relationship with sugar intake, number of brushing times and sex. Conclusion: Dental caries have significant relationship with existence of Candida Albicans in mouth, low salivary PH and smoking (P<0.05). Candida Albicans is the most common type of Candida in oral cavity.

Introduction: In an ideal situation, the wear resistance of a restorative material should be similar to dental enamel. This study was performed to observe the wear resistance of targis wear compared with porcelain, composite, and natural enamel. Materials & Methods: In this in vitro study, 120 samples (2×8×13mm) were prepared including 60 Targis samples (140 Dentin Targis veneered with S1 Incisal Targis), 20 porcelain samples (VITA VMK95-A2 Incisal), 20 composite samples (Tetric-ceram HB-A2) and 20 natural enamel samples (buccal surface of maxillary central tooth). The samples were mounted in Acrylic block and placed in a wearing machine (periods=30000 times, frequence=198 cycles per second, pressure=300gr invironment=artifitial saliva solution) after finishing by silicone carbide paper (240-1000) for 20 minutes. The samples were studied in three groups: Targis-Porcelain, Targis-Composite and Targis- Enamel. Vertical reduction of each sample was measured by a digital caliper (Mitutoyo, Japan) with a precision of 0.01mm. The results were analyzed by a T-test and SPSS software. Results: Porcelain was 3.5 times more resistant to wear than Targis and the difference was statistically significant (P<0.05). The wear resistance of targis was not significantly different from Tetric ceram HB composite (P>0.05). When compared to enamel, it was observed that Targis was less wear resistant but the difference was not significant (P>0.05). Conclusion: According to the results, targis, having suitable mechanical properties, maybe a good alternative for porcelain composite.

Introduction: Fracture of acrylic resin denture base is a common problem in maxillary dentures. Because the stresses in mouth on the denture base are of flexural type, the aim of this study was to determe the effect of palatal shape combined with acrylic resin thickness on the flexural strength of the denture base. Materials & Methods: In this experimental study, 48 stone casts in 3 groups (shallow, medium and deep palatal vault) were prepared. Eight casts of each palatal form were covered with a single layer of base-plate wax and eight were covered with two layers. Patterns were invested and processed with Acropars acrylic resin in the same manner. Flexural strength, deflection and fracture load were measured with DARTEC testing machine. Statistical analysis was performed using multivariate ANOVA, Kruskal-Wallis and Mann Whitney tests. Results: The results showed that the flexural strength of shallow bases were significantly different from medium and deep palatal shapes at both thicknesses (P<0.001). There were no statistically significant differences in flexural strength between the medium and deep palatal shapes (P=0.583). Increasing the base thickness significantly increases the flexural strength in each palatal shape (P<0.001). Conclusion: This study revealed that palatal shape and base thickness have significant effects on flexural strength of denture bases. In shallow palates, increasing the thickness of denture base can enhance flexural strength of denture.

Introduction: One of the most important disadvantages of using of tooth colored restorations is microleakage. This is more noticeable when there is a cavity with dentinal walls. Despite all improvements in dentin bonding agents, thusfar, no adhesive has been able to overcome microleakage between resin-dentin. The purpose of this survey is investigating the effect of filler on microleakage of self-etch adhesives with dentin and SEM interfacial morphology evaluation. Materials & Methods: Class V cavities were made on extracted human premolars (n=60). Then the teeth were randomly divided into 6 groups based on type of adhesives used. Next teeth were grouped as filled adhesive (Xeno III, Clearfil SE Bond, Excite) and three grouped as unfilled adhesive (iBond, Bistite II, Single Bond). After restoration, specimens were treated by thermocycling and a dye penetration test was done. Then longitudinal sections were made toward the direction of the buccal lingual and were observed carefully under a stereomicroscope for any leakage. From each group, 2 samples were prepared for investigating micromorphology of resin under an SEM electronic mircroscope. Data was analyzed by the Kruskal-Wallis test and Mann-Whitney test with an accuracy level of 0.05%. Results: Using the Mann-Whitney test, it was clear that in the one-step self-etch adhesive, the filled type (Xeno III) had reduction in microleakage compared to the unfilled type (i Bond). On the two-step self-etch and total etch adhesives, there was no significant difference between filled and unfilled adhesive in reduction of microleakage. In SEM investigations self-etch adhesives make thinner hybrid layers, but there are more resin tags with more regularity in this system and resin is well penetrated in the spaces due to demineralization and was polymerized.Conclusion: The filled type of one-step self-etch adhesive (Xeno III) had more reduction in microleakage than other groups. There was no significant difference between the two types (filled and unfilled) two-step self-etch and total etch adhesives in reduction of microleakage. It was clear that if self-etch adhesive is used carefully give better sealing compared to total etch adhesive. Because they can infiltrate the spaces made due to demineralization and get polymerized.

Introduction: Resorptions of permanent incisors are a rare complication of ectopically erupting maxillary canines but when they occur they may lead to extraction, orthodontic treatment or both. The purpose of this study was to assess the incisor root resorption adjacent to impacted maxillary canines using conventional radiographs and CT scan. Materials & Methods: Fourteen patients (13-20 years) with 18 impacted canines were studied. Upper alveolar bone CT scans of the patients and their periapical and panoramic images were analyzed for detecting incisor root resorption caused by impacted canines. Degree of root resorption was assessed on CT scans on the basis of the self-designed classification. Buccolingual, mesiodistal and superioinferior location of resorption of incisors’ roots and their longitudinal extension were assessed using CT scans in regard to the number of CT cuts showing the resorption. Results: All of the teeth adjacent to impacted maxillary canines showed resorption. The most prevalent resorption site (84.6%) was detected in lateral incisors. 61.5% of involved teeth in CT scan did not show any resorption in the conventional radiographs and the others (38.5%) were questionable. In 77% of cases, resorption of palatal and distopalatal surfaces of involved roots were not detectable in conventional radiographs. Assessment of canine eruption angle in panoramic radiography revealed that this angle did not have any significant role in developing root resorption of adjacent teeth.Conclusion: Conventional radiographs are not able to detect root resorption of the incisors adjacent to impacted canines. Therefore, in cases which intensity and extension of root resorption has an effect on treatment plan and prognosis, CT scan is strongly recommended.

Introduction: Severe Early Childhood Caries (SECC) is one of the most common diseases in childhood. Etiology of SECC is multifactorial and both genetic and environmental factors play important roles in the pathogenesis of the disease. Genetic variation of the host may contribute to susceptibility for dental caries. Genetic factors such as Human Leukocyte Antigen (HLA) have been recently introduced as a predisposing factor. The aim of this study was to look for an association between HLA-DRB1*04 and HLADQB1*06 with SECC for early diagnosis as well as prevention of the disease. Materials & Methods: In this cross-sectional study we extracted the genomic DNAS from the whole blood samples of 44 patients with SECC and 35 caries free children (control group) by salting out method. We amplified the genomic DNA by PCR sequence specific primer (PCR-SSP) and then HLA-typing was performed for both alleles. The data were analyzed using Logistic Regression, Fisher's exact, chi-square and Student t test with 95% significance level.  Results: The results revealed a significant increase in the frequency of HLADRB1*04 in the patient group (P-value=0.019). The odds ratio for this allele was detected to be 10. Frequency of HLA-DQB1*06 allele was not significantly different between the two groups (P-value=0.37). Conclusion: The above results suggest that HLA-DRB1*04 maybe related to the susceptibility to SECC. Thus HLA-DRB1*04 detection as a molecular marker for early diagnosis of SECC can be recommended.

Introducion: The Human teeth have many anatomical variations and treatment of each tooth is under the influence of its configuration. Therefore, recognizing canal configuration is necessary for correct endodontic therapy, and lack of information about canal configuration causes failure in therapy. Since one of the most effective factors on canal configuration is race, we planed to have a laboratory (in vitro) research in the city of Isfahan. Materials & Methods: This study was descriptive, and was done on 160 extracted first maxillary premolars and second mandibular premolars, which were collected from a number of university clinics and private offices in Isfahan. Teeth were decalicfied, injectetd with dye, and made transparent to determine the number of root canals and  their type. Finally, the teeth were  additionally cut in cross sections in three points of the root and canal configurations of teeth were evaluated. The specimens were classified according to the Weine configuration by naked eye. Results: 1- In the clearing method: a) First maxillary premolars: 80 total sample size  Type I (6/25%), Type II (22/5%), Type III (67/5%) and Type IV (3/75%). b) Second mandibular premolars: 80 total sample size: Type I (91/25%), Type II (6/25%), Type III (0%) and Type IV (2/5%). 2- In sectional method: a) First maxillary prmolars: 80 total sample size: Type I (2/5%), Type II (23/75%), b Type III (70%) and Type IV (3/75%). b)  Second mandibular premolars: 80 total sample size: Type I (88/75%), Type II (8/75%), Type III (0%) and Type IV (2/5%).Conclusion: In other countries many researches on this subject have been done using different methods on the internal anatomy of teeth and the results are different form this study. It appears that the differences are due to genetic or race factors and methods used. Additionally, results of different studies indicate that more attention should be paid to studies on canal configuration of these teeth.

Introduction: Plasma cell gingivitis is gingivitis  which includes these clinical features: red and loosely gingival enlargement, sometimes is granular that with easy bleeding and usually dose not cause attachment loss. In the histologic feature of this lesion there are closed plasma cells in under connective tissue that have extended to the oral epithelium. Causal factors include: allergic factors such as chewing gums, toothpaste, autoimmune reaction, hormonal imbalance and hematologic infiltration. Howeres sometimes there is no clear cause. The aim of this study was case report of plasma cell gingivitis and the way to treat this lesion. Result: The case was a 14 year-old girl  whose chief complain was gingival bleeding. In an intra oral examination there was diffused  red gingival enlargement in the anterior and right sextants of the jaw. In an extra oral examination there was no significant finding. Hematologic laboratory test was normal. In a radiographic feature, marginal bone loss was not detected and in a histopatologic feature there were acanthotic epithelium with closely infiltration of inflammatory cell with dominant plasma cell in under lamina properia. Surgery was performed by flap method in order to eliminate gingival enlargement and then the patient fallowed during the maintenance phase. Discussion: In this case there was not any recurrence of the disease during the 6 month fallow up and any special allergic cause related to this patient was not detected. However, this patient was in pubertal age, and there may be a corelation to hormonal imbalance and this is one suggested causal factors.