Journal of Mashhad Dental School
Year:2006 | Volume:30 | Issue:1-2|Papers Count:25

Introduction: The purpose of this study was evaluation of the prevalence of dental abscesses, treatment and healing rate in the patients who referred to the pediatric department of dental school. Materials & Methods: This descriptive cross-sectional study is based on the question answer and clinical evaluation of children with dental infections. During this study, 93 children (50 girls, 43 boys) with dental abscesses coming to the pediatric department for treatment, were evaluated. Chi-square test was used for statistical analysis. Results: In this evaluation, 93 children (50 girls and 43 boys) were studied and evaluated. The most abscess prevalence was in 6 year old children (20.4%), among which 68.4% were acute abscess. The most teeth involved were the primary molars of mandible. The major treatments were combination of antibiotic therapy, drainage and pulpectomy. Conclusion: According to high prevalence of dental abscesses in primary molars at the age of six in our society and importance of maintaining them until 10-12 year old, early diagnosis and treatment of dental caries and abscesses is necessary.

Introduction: Radiolucent lesions are common bony lesions and can be seen in the forms of periapical, pericoronal, interradicular and lesions not necessarily related to teeth. The purpose of this study was to determine the epidemiology of radiolucent lesions in patients who were referred to radiology department of Mashhad Dental School. Materials & Methods: In this prevalence descriptive study, panoramic radiographs of 256 patients referred to the radiology department were evaluated for one year and the frequency of their lesions were determined according to age, sex, number of lesions, site of occurrence, shape, border and effects on surrounding structures. The data were statistically analyzed using chi-square test. Results: From 51 radiolucent lesions, the periapical granuloma was the most common lesion (45.1%) followed by periodontal disease (19.6%), radicular cyst (13.7%) dentigerous cyst (3.9%), cherubism, traumatic bone cyst, squamous cell carcinoma and central giant cell granuloma (2%). These lesions occurred predominantly at the second decade of life and most frequently in men. Conclusion: Three common radiolucent lesions were periapical granuloma, periodontal disease and radicular cyst. Periapical granuloma occurs predominantly in mandible while periodontal disease and radicular cyst occur in maxilla more frequently.

Introduction: Different behavior of stainless-steel wires manufactured by different companies is observed in clinical situations. The purpose of this study was to compare the load-deflection rate of a specific size of stainless-steel wire from different companies which are available in Iran's commercial market. This comparison allows classification of these wires and also the wire with best characteristics will be clarified. Materials & Methods: This experimental study was carried on cross-sectional base. Round 0.016 inch stainless-steel wires from 9 different companies were used in this investigation. 14 wires from each company were chosen on random base. 14 Wires from each company were divided in two groups of 7, group A and B with 3 and 1.5mm deflection respectively. The tests were done using Zwick testing machine model Z250. Loading and Unloading forces of wires in predetermined distances were measured. The total of 126 tests was measured. Upon these measurements, the load-deflection curve was drowning. Using SPSS software the one-way analysis of variance (ANOVA) was done and each wire from a company was compared to other companies using Tukey analysis. Results: The load deflection curves obtained were similar to typical curve of stainless-steel wires. The one-way analysis of variance (ANOVA) showed that there was no significant difference between the wires belonged to group A in three different deflection, i.e. 2.5, 2, and 1.5mm at a level of 5%, but he difference between the wires belonged to group B in 1.5 mm deflection was significant (P<0.001). Conclusion: In this study it was found out that among the 9 different wires, tested, the RMO wits produced the minimum force levels and Dentaurum wires produced the maximum force levels in both groups. This means that RMO wires had better tissue compatibility. Moreover, it was found out that even the wires made by the same factory did not have a similar behavior. Among the tested wires, the ortho technology wires had minimum and the GAC ones had maximum similarity to each other.

Introduction: Osteoblast and periodontal ligament cells are major cells for wound healing after root end resection. The interaction of osteoblast with directly contact filling materials could play a critical role in healing of surgical lesion. Adhesion and spreading of cells on material surface are the initial phase for cellular function. The purpose of the present study was the evaluation of morphology and attachment of human osteoblasts in presence of Gray MTA, white MTA and IRM as root end filling material. Materials & Methods: This study was a descriptive study the human osteoblasts (MG-63 cell line) were prepared from Iranian Pasteur Institute; Cellular Bank, were grown in PRMI 1640 medium. The testing materials were mixed according to the manufacture's instruction, inserted into the wells of 24-well flat-bottomed plate, and condensed to disk of 1mm thickness and 1×1mm diameter. Cells were added to the materials after two weeks. During 1,3,7 days intervals, the disk of materials along with cells were grown on their surface, examined by a scanning electron microscopy. Results: First day: After first day cells in presence of white and gray MTA showed adhesion and normal morphology, in presence of IRM were totally round. Third day: After third day osteoblasts adjacent to white and gray MTA were flat with adhesion to both materials. In presence of IRM they were round and with no attachment. Seventh day: In seventh day cells appeared with adhesion and normal morphology. Adjacent to IRM cells were round with no attachment. Conclusion: The results indicate that human osteoblasts have a favorable response to gray and white MTA compared with IRM.

Introduction: The importance of determining working length in root canal therapy is clear for each clinician, and conventional radiography has been the technique of choice so far. But developing computerized technology in radiology and it's show up devices in the market, having several advantages, makes the tendency to use such technology more and more. Despite the many studies in this field, the accuracy of these devices is still unclear. The purpose of this study was to compare the accuracy of conventional radiography and digital radiography in order to estimate the working length of root canal. Materials & Methods: For this in experimental vitro study 17 root canals of maxillary and mandibular molar teeth on human skulls were selected. Size #15 files were placed in canals in order to assess working length. Then two radiography were taken from each canal: one using conventional and the other one using digital technique, through parallel method of radiation accomplished by special positioning devices. Next the teeth were extracted and real working length was determined. After that two independent observers estimated working length in both conventional and digital radiographs. Finally the mean working lengths of each group were compared with the real amounts using paired t-test analysis. In all tests a significance level of 0.05 was determined. Results: Statistical analysis revealed that digital radiography was more accurate than conventional radiography in determining the working length (P=0.019). Conclusion: Due to the greater accuracy and other advantages of digital radiography, this method is strongly recommended, regarding the similarities between the study and clinical situation for working length determination.

Introduction: Today many patients with some reasons need the use of anticoagulant drugs, that interruption of these drugs may be dangerous. The purpose of this study was to evaluate the use of tranexamic acid 5% mouthwash to control hemostasis in patients therapeutically anticoagulant medication undergo dental extraction without interruption of medication. Materials & Methods: This study was a descriptive study and the data collection method was direct observation. A total of 55 patients undergone 167 dental extraction without interruption of oral anticoagulant medication, were required to rinse with 10 ml of a tranexamic acid 5% mouthwash 4 times a day for 7 days postoperatively. Dental extraction was carried out by two surgeons. Data were analyzed using SPSS statistical software and descriptive analyzed done. Results: Of 55 patients treated, 1 presented with postoperative bleeding on the third day after operation (1/8%). In these patient international normalized ratios was grossly elevated on the day of the bleeding (6.1). Conclusion: This study supports the consensus that simple dental extraction in patients maintained on oral anticoagulant therapy with use tranexamic acid 5% mouthwash, can be performed without reduction or intruption dose of anticoagulant medication, and hemostas occurred well.

Introduction: The purpose of this study was to evaluate the concordance between clinical diagnosis and pathology report of patients referring to department of oral medicine of Mashhad dental school. Materials & Methods: In this descriptive retrospective study, personal information and disease (or lesion) characteristics of 170 patients who had been referred to the department of oral medicine for biopsy during the past 2 years, were collected through questionnaires and were analyzed Chi-square and Fisher exact statistical tests. The diagrams were drawn with use of Microsoft office SPSS software. Results: 81.2% of the clinical diagnosis was consistent with pathology reports. In 18.8%, the clinical diagnosis was not confirmed histopathologically. The greatest concordance was observed for lichen planus, inflammatory hyperplasia and leukoplakia whereas pemphigus, SCC and systemic lupus erythematosus revealed the lowest concordance. Conclusion: Although a great concordance was observed between clinical diagnosis and pathology report, the inconcordance was significant and establishing strategies for minimizing it, is necessitated.

Introduction: In our country were the youth form a high percentage of the population and we can observe their growing presence in athletic fields, the study of prevalence of traumatic dental injuries and the ways of preventing them seems necessary. The purpose of this study is to specify the rate of prevalence of traumatic dental injuries caused by non- martial sports in the city of Mashhad. Materials & Methods: In this cross-sectional study, 409 male athletes from 12 gyms (both professional & non- professional) in Mashhad were examined for traumatic dental injuries in 3 kinds of non-martial sports (wrestling, football and basketball) through a questionnaire containing data about their athletic backgrounds. Statistical analysis was made by Epl6 software and was analysed using X2 statistical test. Results: 1. Out of the total number of those examined 33% had traumatic dental injuries. 2. The highest rate of injuries was related to the upper jaw dental injuries (75.2%) central incisors (60.5%) and the incisal third (26.1%). 3. Out of all those having traumatic dental injuries 24.7% had referred for comprehensive treatment. Conclusion: Considering high rate of prevalence of dental injuries among athletes (33%) and with regarded to the outcomes caused by not having proper and timely treatment, it seems necessary to instruct sports coach's sanitary instructurors of schools, and the athletes about the importance of using mouthguards and the early treatmet of dental injuries.

Introduction: The final objective of root canal therapy is to create a complete seal along the length of the root canal system from the coronal opening to the apical termination and to accomplish the best adaptation from obturation material with canal walls. The tug-back of the master cone is recommended to provide apical seal. The purpose of this study was to determine the influence of tug-back on the quality of the apical seal. Materials & Methods: In this experimental in vitro study, seventy single canal teeth were selected. The crowns were removed; the canals were prepared using a step-back instrumentation technique. Patency of the apical foramen was maintained and the teeth were divided into 2 experimental groups of 32. In the first group obtruration was achieved by tug-back in master cone and in the second group without tug-back using lateral condensation technique. Six teeth were used as control group, out of which three served as negative and three as positive controls. The teeth were placed in 100% humidity and 37°c for three days. The roots of the teeth were coated with two layers of nail varnish and one layer of stick wax except for the 2mm of apical end. Teeth were immersed in methylenblue 2% solution for one week and finally the teeth were sectioned vertically. The depth of maximum dye penetration for each tooth was recorded by two evaluators with stereomicroscope. All results were submitted for statistical analysis using Student’s t-test. Results: The mean linear dye penetration for experimental group with tug-back in master cone was 6.918±2.140 mm while this was 8.110±1.929mm in the group without tug-back. This difference was statistically significant (P=0.02).  Conclusion: The results of this study showed that the tug-back in master cone provided a significantly better apical seal.

Introduction: Following increasing people’s demand for having aesthetic, functional and simultaneous benefits of composite and amalgam restorations, combined restoration of composite-amalgam has been introduced. The aim of this study was to evaluate the effect of there methods of surface treatment on composite-amalgam fracture strength. Materials & Methods:  In this experimental invitro study, on thirty uniform and sound human maxillary premolar teeth mesiobuccal class II cavities were prepared so that in all specimens the thickness of buccal reminder enamel was one millimeter. They were divided randomly into three groups of ten and filled with amalgam. After 24h in each tooth, thin mesiobuccal enamel was removed and amalgam surface were veneered with Tetric Ceram composite by one of the three following methods. In A and B groups after etching with phosphoric acid, Scotchbond Multi-purpose and One Coat Bond were applied respectively. In group C after sandblasting and acid etching, margin bond unfilled resin was applied for adhesion of composite to amalgam. Finally for fracture strength measurement, the specimens were loaded under Instron testing machine at a crosshead speed of 1mm/min with 45° angles. Fracture areas were also considered from stand point of CEJ location and type of debonding (adhesive – cohesive – mixed). Data were analyzed with One Way ANOVA and Duncan tests. Results: Mean fracture strengths in three methods were significantly different (P=0.02). Group C had the highest and group B had the lowest fracture strength. In all three groups, the most common type of debonding was adhesive and above to the CEJ. Conclusion: The highest mean value of fracture strength was obtained in group with amalgam sandblasting followed by application of unfilled resin which did not differ significantly with Scotchbond Multi-purpose group. However it differed significantly with One Coat Bond group.

Introduction: One of the important stages in fixed partial dentures is the preparation of stone die which is in fact the replica of the prepared tooth and should have the maximum adaptation in replicating it. Plaster die may be scratched by the instruments during the wax up and this leads to loss of precision. Microfilm is used as a lubricant to prevent wax from adhering to the stone and is applied to die. The objective of this study was to evaluate the effect of die separator (microfilm) in different situations on the hardness of stone die. Materials & Methods: In this experimental study forty dies were made after taking PVC impressions with the diameter of 2 and height of 1 centimeter with gypsum type 4 (extra hard stackable type IV dental stone), according to the manufacture  instructions. Dies were divided into four groups of ten and after 24 hours of keeping in the room temperature for reaching the maximum tensile strength (final dry tensile strength) they were used as follow: 1- Control group on which, microfilm was not applied 2- Group A was immersed in microfilm for ten minutes and was immediately examined for hardness. 3- Group B was immersed in microfilm for 10 minutes and was stored in room temperature for 12 hours and then microfilm was applied again by a brush. 4- Group C was immersed in microfilm and was stored in room temperature for 24 hours and microfilm was applied again using a brush. All of the groups were examined for hardness under 25 gram forces for 5 seconds and the data was processed for statistical analysis. The one way variant analysis and multiple Dunnet, Tukey test and kruscal vallis test were used and the results were examined with 95% confidence interval. Results: The maximum surface hardness was found in the control group equal to 77.8±12.5 and decreased in groups A, B and C to 41.1±7.4, 30.7±5.9 and 22±2.5 respectively. ANOVA statistical analysis showed a significant difference between the four groups (P=0.001). Dunnet analysis showed a significant difference between all the groups and the control group (P= 0.001). Groups were compared in pairs using the Tukey test and only groups B and C didn’t show a significant difference. Conclusion: According to this study the following results were acquired: 1. Applying microfilm to the stone dies resulted in significant decrease in surface hardness. 2. Applying microfilm resulted in a significant decrease in surface hardness after 12 hours. 3. There was no significant difference in surface hardness between 12 and 24 hours after microfilm application.

Introduction: It is necessary to mention that 4% of malignancies include pharyngeal and oral cancers. One of the treatments is radiotherapy in addition with chemotherapy and surgery. Radiotherapy of head and neck can cause some complications with impression on mucos. Regarding this point, we decided to study different effects of radiotherapy on gingival and oral mucosa. Materials & Methods: This descriptive analytical study was performed on 30 patients with head and neck cancers referred to radiotherapy department of Ghaem Hospital. Data collection method included interview, clinical examination and patient’s medical file investigation. The data was collected through relevant forms. The relationship between deferent dosages of radiation on gingival health and oral mucosa was investigated. Data analysis was done with use of GLM, Cochran, MANOVA tests Via SPSS V. 11.5 software. Results: A significant relationship between irritation of oral mucosa ulcer development, mucositis and increase in radiation dosage was observed. But there wasn’s any significant relationship between candidosis, ANUG, perleche and radiation dosage. Periodontal Index (PI), Gingival Index (GI) and Papilla Bleeding Index (PBI) showed on increase, but due to limited time of study, no changes on gingival recession was observed. Plaque Index (PlI) decreased during treatment process due to increase in oral hygiene. Conclusion: There was a direct relationship between oral radiotherapy complications and increase in radiation dosage. With attention to this point that some complications such as ANUG and perleche were not observed, doing a study with longer duration is recommended.

Introduction: The thalassaemias, a heterojenous group of inherited disorders, are caused by deficient synthesis of one or more of the chains of human haemoglobin. Oral–facial manifestations such as maxillary protrusion, severe malocclusion, marked open bite, saddle nose, protrusion of upper lip and glossitis are seen in thalassemia. Materials & Methods: In this cross-sectional descriptive study, 165 patients, consisting of 97 boys and 68 girls who supported by thalassemic society were examined. Study variables were age, sex, dental caries and gingival status. Data were analyzed by Chi-square, T test and variance analysis. Results: Mean DMFT index was 3.6±0.2, and the maximum belonged to more than 18 year old children (6.31±3.28). DMFT=0 and dmft=0 was found in 28.2% and 34.4% respectively. In relation to gingival status 33% had gingivitis, 1.8% had periodontitis and 64.8% normal gingival. Conclusion: According to the high incidence of caries and gingivitis in thalassemic patients need to be encouraged for effective preventive measures, education and dental treatment for this high risk group.

Introduction: Dental caries had been known historically as the most common infectious disease. Miniflap is one of the techniques used for better access to class V caries. The aim of this study was making a comparison between periodontal index after class V restorations of composite resin and glassionomer by miniflap. Materials & Methods: This clinical trial study was carried out on 30 premolar teeth in patients who referred to Babol dentistry faculty with class V caries, which their gingival margin was 1mm apical to the free gingiva, in maximum. Two incisions in mesial and distal of the tooth at the level of attached gingiva and thereafter conventional class V cavity preparation were performed. Then teeth were divided in to two groups. The first group was restored by glassionomer (Fuji II Lc) and second group by heliomolar resin composite. Patients were followed up in, 1, 3 and 6 month after restoration concerning gingival index, Bleeding index, plaque index, probing pocket depth index and clinical attachment level and the findings were analyzed by Student’s t-test. Results: Comparing the mean of periodontal indexes before and after restoration by glass ionomer showed that only bleeding index was changed significantly 6 months after restoration. The mean of periodontal indexes including CAL and PPD changed significantly before and after restoration by composite in 1 , 3 and 6 months follow up. For a better comparison of indexes between two groups ∆ (the change rate of different indexes) in 1, 3 and 6 monthes after restoration was assesed and showed that this difference was significant in CAL and PPD index between intervals, except for the restoration time after six monthes. Conclusion: Periodontal indexes in gingiva adjacent to cavity restored by glass ionomer indicated better gingival adaptation for this material compared to composite.

Introduction: Various factors affect the distribution of stress and fracture resistance of restored teeth by post and core. One of the major causes is the remaining body of the teeth, (ferrule) which was embraced by crown. The purpose of this study was to asses the effect of developing the ferrule via a crown lengthening procedure, on the fracture strength of endodontically treated teeth. Materials & Methods: 24 recently extracted second premolar of mandible was selected in this descriptive study and their crowns were cut so far that no more than 15 mm of the root remained. Then they were divided randomly into two groups of 12 and their canals were undergone rootcanal therapy. In the first group, a post–core and full metal crowns were made without ferrule, while in the second group with changing in the optimum ratio of the crown/root height, 2mm ferrule was designed and then the cast post- core and full-metal crowns were made. Finally, in both groups, a compressive load with 1 mm per minute speed and an angle to 150 on the long axis of the tooth was applied. The force was exerted in mesial marginal ridge, in 7 teeth and on the buccal cusp edge in the other 5 teeth to induce fracture. Statistical analysis of the data was performed with student t-test, chi-square and two-way ANOVA analyses. Results: 1. There was a significant difference between the mean of fracture load in the ferrule and non-ferrule groups (P<0.001). 2. No significant difference in the mean fracture load was observed when the load was applied in the buccal-cusp edge instead of mesial marginal ridge. Conclusion: By adding a 2 mm cervical ferrule on top of the finishing line of mandibular premolars restored by cast post-core and crown, we can increase the fracture resistance of these teeth.

Introduction: One of the important points in dentistry is retentive strength of crown on teeth or bridge on abutments. One the effective factors in retention is cement type and its relation to core buildup materials. One of the core buildup materials which have a wide usage in Iran is the commercial Core Max II composite. The aim of this study is to compare the retention of cemented crowns by zinc phosphate, glassionomer and resin cements of panavia F on Core Max II dies. Materials & Methods: In this research silver cast alloy crowns were made on 90 similar dies of core max II, these dies were divided to 3 groups of 30: In each group the crowns were cemented on Core Max II dies with one of three cements. Then the crowns were pulled tensively in Instron machine, and the results were analyzed with SPSS V.11.5 software. In this study the analytic tests of ANOVA and Tuky test were used ( a= 0.05). Results: According to quantitative analysis between 3 cements glassionomer, zinc phosphate and panavia F had significant difference (P=0.001). The evaluation of mode of failure revealed that the most common failure pattern in panavia F was cohesive in core (80%), which reveals more retention between core, panavia (as cement) and crown, however in glassionomer this was (26/7%), and there was no cohesive failure in zinc phosphate. Conclusion: Considering retentive characteristics when the Core Max II composite cores are made the best cements are panavia F and glassionomer respectively.

Introduction: Having an appropriate diet in toothless patients with complete dentures should be considered to provide their required nutritions. In this research, our purpose is to assess serum levels of iron and folic acid in some of the patient referred to the prosthetic department of Mashhad Dental School, both before and after the replacing of prostheses and also to study the serum level changes in them. Materials & Methods: This interventional study was done on 30 cases. A standard questionnaire including two parts, has been used the first contains personal information and the second part contains a chart for information on the primary and secondary serum levels of iron and folic acid. The primary level of iron and folic acid indicates the level of them after three months period, of being toothless. And the secondary level indicates the level of them three months after applying the prostheses (Artificial teeth). For statistical analyses, t student test and t test pair were used. Results: Evaluation of the gathered data in the population of this study in which the mean age was 52.6 years old, demonstrated low iron and folic serum levels, comparing to normal range, both in the first and second sampling. Also, the assessment of the secondary iron level changes compared to its primary level didn't show any significant decrease, while the folic acid decrease was quite significant (P=0.003). The study of these changes based on different sexes, only demonstrated a significant difference in iron serum level (P=0.012); while in the case of folic acid there was no difference in the secondary decrease between men and women. Conclusion: According to findings of this research, the role of healthy teeth in having an appropriate diet and providing calorie and required nutritions, due to effective chewing power, was emphasized, applying substitute prostheses could not have an correcting the nutritional diet of these subjects. Therefore, it is suggested these patients should get education on correcting their diet with supplements and other nutritions, or having control periods for checking their nutritional health.

Introduction: One of the precise methods for evaluating periodontal responses to orthodontic forces is finite element method (FEM). In the following study PDL of anterior maxillary teeth (central, lateral, canine) has been analyzed by FEM after applying intrusive forces. The Aim of this study was to evaluate induced stresses in PDL of anterior teeth by application of intrusive forces between lateral incisor and canine. Materials & Methods: Solid works software was used to translate bidimentional images of the maxillary anterior teeth (central, lateral, canine) into three dimentional images. PDL and alveolar bone around these teeth were simulated and anterior teeth were positioned in an ideal arch with appropriate tip and torque, and rectangular wire was stabilished rigidly on labial surfaces of the teeth. Models were modified to “Finite element model” by means of MSC-NASTRAN software. Intrusive forces (35 gr) were applied on the wire between lateral and canine and induced stresses were analyzed by means of MSC-PATRAN. Results: By delivery of intrusive forces between lateral and canine, maximum stresses were found in PDL of lateral incisor (4.23×10-3 N/mm2) and minimum stresses were observed in PDL of central incisor (2.02×10-6 N/mm2). Conclusion: By application of intrusive forces between latral incisor and canine, maximum stresses were focused at the apex of lateral incisor and minimum stresses were in apical third of Central's root.

Introduction: The replacement of missing teeth with late dental implants has become an acceptable and standard treatment modality. However, there have been only a few studies evaluating the immediate dental implants. The aims of this study were: 1) To evaluate the possibility of inserting dental implants into extraction sockets immediately after extraction. 2) To assess osseointegration after immediate implant insertion clinically. 3) To evaluate the changes in depth and width of defects surrounding implants as well as change in distance from cover screw to alveolar crest after insertion of fixtures following immediate implantation and assess the efficacy of this method in preserving height and width of the alveolar ridge. Materials & Methods: In this clinical trial which had a before-after design, five implants were inserted in 3 patients immediately following extraction of the teeth number 44, 47, 11, 14 and 23. HA coated Dyna implant systems were used in this study. At the initial stage as well as the second stage of surgery the following parameters were measured at 6 sites around each implant: width and depth of remaining defect around the neck of fixtures and the distance from the covers crew to crest. The role of baseline defect parameters on the final configuration of defects was analyzed statistically, by paired t-test and multiple regressions. Results: Defect depth and defect width showed improvements of 3.4mm (90%) and 1.8mm (94.5%) respectively which were statistically significant. Improvement in the width and depth of defects had negative correlation with baseline defect width and depth. Furthermore, the distance from alveolar crest to the cover screw at baseline had a significant influence on the reduction of the defect width at the re-entry visit. Primary stability at the insertion visit had a significant and positive effect on the remaining defect depth at the re-entry, although its effect on the defect width was positive but insignificant. Sites with primary stability showed a 10 times smaller distance from cover screw to the crest, which was statistically significant. Conclusion: Insertion of immediate implants into extraction sockets using Dyna HA coated implants are clinically possible, with a predictable and successful outcome. In addition, primary stability of implants in such sites, although is not essential for clinical osseointegration, it may facilitate the bone fill in the defects around immediately inserted implants.

Introduction: Severe rotation of individual tooth is a kind of malposition that interferes with esthetics and may cause occlusal interferences. Case report: A ten – year – old boy with severely rotated (90 degree) maxillary right central incisor and lack of space was referred to mashhad dental school. At the first stage a removable appliance was used to make enough space and then a whip spring was used for derotation of rotated tooth. After correction of rotation a retentive removable appliance was used for a long period of time to decrease the chance of relapse. Conclusion: Combination of removable appliance with whip spring can be used successfully in the treatment of rotated teeth. Early treatment of these severely rotated teeth improves esthetics and may lead to decreasing the chance of trauma to the teeth and periodontium.