Showing 88 results for Rat
N. Eshghyar , N. Kafie ,
Volume 11, Issue 3 (6-1998)
Abstract
In this study we try to clear the prevalance of age and sex and clinical and radiographic manifestations of primary hyperparathyroidism. In this duration 47 patients with primary hyperparathyroidism that bed in two important hospitals in Tehran were studied.The ratio between women to men was 7 to 1 and most prevalance of disease were in fouyth decade. The pain boon was the cheif complain of patients and osteopenia was the most radiographic findings.In addition a case of primary hyperparathyroidism with mandibular and other bone involvement was reported.
A A. Khoshkhoonejad , A A. Miremadi , N. abolfazli ,
Volume 11, Issue 3 (6-1998)
Abstract
The present clinical trial was designed to evaluate the regenerative potential of periodontal tissues in degree II furcation defects at mandibular molars of human using a slow-resorbing collagen membrane and a surgical treatment technique based on the principles of guided tissue regeneration.The patient sampleinclude 8 subjects who had periodontal lessions in right and left mandibular molars regions, including moderate to advance periodonal destruction within the radicular area. Following a baseline examination including recording the clinical measurements (PD, Al, HC, F.G.M) , the furcation- involved molars were randomly assigned in each patient to either a test or a control treatment procedure. Included the evevation of mucoperiosteal flaps, recording measurement from the cemento enamel junction (C.E.J) directly coronal to the furcation area to the alveolar crest and to the base of the defect-Horizontal furcation measurements were also made using a William's probe, finally a collagen membrrane placed on the involved area to cover the entrance of the furcation and adjucent root surfaces as well as a portion of the alveolar bone apical to the crest. The flaps were repositioned and secured with interdental sutures. A procedure identical to the one used at the test teeth was Performed at the control teeth region with the exception of the placement of the collagen membrance. Following surgery all patients were placed on a plaque control regimen. All Patients received normal postsurgical care and at 6 month post-surgery were scheduled for re-entry surgery. Before re-entry surgery all clinical parameters recorded again. The re-entry mucoperiosteal flaps were designed to expose the furcation area for measurements, as describedabove. There was clinical improvement in all measurements made in both the test and control patients (especially in test group) over the 6 month period. The horizontal and vertical furcation measurements did yield a statistically significant imporvement when companing the test patients to the control.
M. Paknejad , R. Ranjbar ,
Volume 12, Issue 1 (8-1999)
Abstract
Growth factors are biological mediators that have a key roll in proliferation, chemotaxy and differentiation by acting on specific receptors on the surface of cells and regulating events in wound healing.They can be considered hormones that are not released in to the blood stream but have one a local action. Some of these factors can regulate premature change in GO to Gl phase in cell devesion cycle and even may stimulate synthesis of DNA in suitable cells, Growth substances, primarily secreted by fibroblasts, endothelia! cells, macrophages and platelet, include platelet derived growth factor (PDGF), insulin like growth factor (IGF) transforming growth factor (TGF)a and (3 and bone morphogenetic proteins BMPs that approximately are the most important of them. (BMP)s could be used to control events during periodontal, craniofacial and implant wound healing through favoring bone formation According toLynch, combination of PGDF and IGF1 would be effective in promoting growth of all the components of the periodontium.The aim of this study was to characterize growth factor and review the literature to determine the mechanism of their function, classification and application in implant and periodontal treatment.
A. Azari ,
Volume 12, Issue 2 (9-1999)
Abstract
After approximately 40 years of experience in the field of resin - bonded restorations (R.B.R),these restorations arc one of the most controversial. During these years, many suggestions have been made for better performance and increasing durability of these restorations. The aims of this paper are:1 - Reviewing the literature for the so many factors involving the success or failure of R.B.R.2 - Introducing a new and simplified method for increasing the durability and /or relention of R.B.R.
M. Zarrabian , M. amin Sobhani ,
Volume 12, Issue 2 (9-1999)
Abstract
One of the major goals of periradicular surgery is to create a good apical sea! at the apex. This is done by sectioning of 2 to 3mm from the apex, preparation of a class I cavity and filling with a biocompatible material.The purpose of this in vitro study was to determine whether ultrasonic units used for root end preparations could change the surface & structure of resected root ends, as competed to common methods of retropreparation. Eighty-five extracted single rooted teeth were divided into five similar groups. Then instrumented and filled with lateral condensation method. Then three millimeter of apex was resected, retropreparaiions in two groups were done with low speed handpiece and round V) ^ur and cavities in two other groups prepared with the highest power of dentspiay ultrasonic unit with TFI-10 tip and in one other group prepared with the highest power of neo sonic ultrasonic unit with diamond coated CT-1 retro tip.Following root resection and retropreparation the surface of resected root ends were examined for the presence of any cracks or structural changes on the surface of resected root ends with stereo microscope 50x.The results of this study showed thai high power settings of ultrasonic units can increase the potential of crack formation on resected root surfaces. In conclusion it is better to use low power setting of ultrasonic for retropreparation.
F. Agha Hosseini , M. Bakhsi ,
Volume 12, Issue 3 (10-1999)
Abstract
A case involving the rare occurance of hyperparathyroidism in association with neurofibromatosis is reported.Radiographic findings revealed multiple radiolucency which diagnosed as giant cell lesions. Also, high levels of PTH and alkalan phosphatase were found from repeated measurements of the serum.Neurofibromatosis associated with hyperparathyroidism diagnosed in this case report.
Y. Refoua , O. Mahdavi ,
Volume 13, Issue 1 (4-2000)
Abstract
: 32 patients were entered in randomized double blind clinical research. The patients were divided into two groups. Group A(18 patients) were given a single dose of 20 mg Piroxicam one hour pre-surgery. Group B(14 patients) were received 325 mg Acetaminophen every six hours immediately after surgery. The mouth opening was measured pre-surgical treatment. Pain relief was evaluated in both groups lsl and 8th hour after surgery. The mouth opening was measured lsl and 7,b day after surgery. The results showed that the analgesic effects of Piroxicam were higher than acetaminophen, however, the comparison of trismus means revealed no significant difference.
A. Fazel , F. Gerami Panah , S. Zaratti ,
Volume 13, Issue 1 (4-2000)
Abstract
Preservation of bone-implant interface is vital for maintaining of implant treatment. There are some cases in which crown to fixture ratio is increased due to loss of residual ridge. In this condition knowledge of stresses acting over alveolar bone is important in regard to prognosis of treatment. In this study three different crown to fixture ratios evaluated under lateral forces considering stresses generated in the alveolar bone around the implant.Three different models of crown to implant ratios were designed in a single-tooth implant at anterior maxilla.Model No. 1 with ratio of 1:1, model No. 2 (1.5:1) and model No. 3 (2:1) were designed. Then, the differences between stresses under two horizontal loads (70 and 100 Newton) were analyzed by three-dimensional finite element analysis. Principal normal stresses and Vonmises stress were measured in this study.Results indicated that stress concentration were mainly at the crestal bone.Highest stresses were obtained in third model (2:1 ratio), which was approximately twice as first model (1:1) ratio.
J. Mahmodian , A. Kousari , Sh. Mortazavi ,
Volume 13, Issue 2 (5-2000)
Abstract
Dental enamel is the end product of amelogenesis, which can be considered to take place in three interrelated phases. When this complex sequence of cytological and physicochemica! events disrupted by genetic or environmental factors, the function of the ameloblasts may be disrupted permanently or temporarily. The result shows qualitative and quantitative defects that may range from a complete absence of enamel or a slight discoloration. The aim of this study was to determine the prevalence of enamel defects by DDE index in a randomly selection group of 1637 students age 7-12 years old in Isfahan (0.2-0.3 PPMF"). Enamel defects were present on one or more teeth in 27% of the cases. The most common affected tooth was the central maxillary and then first molar of maxilla. The most common affected surfaces were buccal. Hypoplastic defects were found in first molar however premolar and canine were affected by diffuse white lines opacity.
M. : Pak Nejad , Y. Soleimani-E-Shayesteh , Z. Mohammad Zadeh ,
Volume 13, Issue 3 (10-2000)
Abstract
Guided Tissue Regeneration (GTR) is the most recent and common method for regeneration of class II forcation molars. However, it requires membrane, which seems expensive for most of the patients. In order to overcome this problem, Coronally Position Flap (CPF) procedure may be applied which arresting the epithelial cell down growth, follow the same aim. This study is aimed to compare GTR technique utilizing bioresorable collagen membrane and CPF utilizing citric acid. Nine patients with grade II forcation defects were selected. Defects were bilateral that randomly assigned into two groups: GTR and CPF groups. Measurements recorded at baseline and after surgery (6 months). Paired-T test was performed on these data. The following results were obtained after 6 months: In both groups significant reduction in probing pocket depth were measured in GTR and CPF groups, 1.55 Ind 1.88 mm, respectively. Also, open vertical probing depth: 0.33, 1.11 mm. Reduction in forcation weight in both groups was 0.22 mm. Bone fill was observed in 0.33% and 51% of defects. No recession was observed in GTR group, in CPF was 0.11 mm. Loss of attached gingiva was 0.34 and 0.78 mm, respectively. No significant difference was found between clinical parameters except OHPD. Comparison of means at the day (0 and 180) in each group showed the success for regeneration of forca. Considering the results, it can be concluded that CPF may substitute for GTR technique.
Sb. Moosavi , Mh. fathi , Gh. Feizi , V. Mortazavi ,
Volume 14, Issue 1 (7-2001)
Abstract
Bone osseointegration around dental implant can cause earlier stabilization and fixation of implant and reduce healing time. Hydroxyapatite coating can affect bone osseointegration and enhance its rates. The aim of this study was comparison of osseointegration between plasma sprayed hydroxyapatite coated and uncoated dental implants in cats. Four endodontic implants including, vitallium and two stainless steel with and without hydroxyapatite coating were prepared and placed in mandibular canines of 20 cats after completion of root canal treatment and osseous preparation. After a healing period of 4 months, investigation by scanning electron microscopy showed significant difference in ossointegration between coated and uncoated dental implants and average bone osseointegration of coated implants was more than uncoated implants.
M. Pak Nejad, Am. Rokn , H. Semyari ,
Volume 14, Issue 3 (9-2001)
Abstract
The aim of the present study was the histological evaluation of Enamel Matrix Derivative (EMD) effectiveness for regeneration of periodontal defects. EMD activates cementum synthesis, PDL and bone during the maturation stage of follicole. In this research, EMD was used in surgical defects of premolar teeth in four adult sheep. Muccoperiosteal flap was reflected in buccal site of teeth. The buccal bone plate was removed from mesial to distal in 4 mm depth. After eliminating the cementum by bur and its etching, EMD was applied on exposed dentine and flap was sutured. In opposite sites of those teeth (control sites) the same process was performed without etching. After 100 days, sheep were sacrificed and histological study through light microscopic was performed on black sections of operation sites. The results showed that in test sites, regeneration of cementum and bone was 62/5% and 42/5-50% respectively. But in control sites regeneration of cementum and bone was 37.5% and 32/5-42/5% respectively. Also the migration of junctional epithelium in control sites was 8-10% more than test sites. The important point is that in test sites, cementum was completely attached to undermining dentine. But, in control sites, the gap between cementum and dentine was visible. As a result, this study suggests that EMD promotes periodontal regeneration, and EMD application is a successful achievement in regenerative periodontal therapy.
A. Zarifkar , H. Skandaryan , M. Mokhtary , J. Ay ,
Volume 16, Issue 1 (4-2003)
Abstract
Statement of Problem: Eugenol is the most important chemical compound of the clove tree (Eugenia aryophylata) extract. That is widely used in dentistry as a bactericidal and pain relieving agent.
Aim: The aim of the current study was to evaluate the antinociceptive effect of local and systemic administration of eugenol by formalin test in rats.
Materials and Methods: In this research, 56 male Wistar rats, weighing 230±20 g were divided into seven groups (n=8). Ten minutes before formalin test, different doses of eugenol (12.5,25,50 mg /in groups 2,3,4 respectively) were injected to the right hind paw of the rats subcutaneously. In- group 5 eugnol (50 mg) was. injected to the contralateral hind paw. In group 6 eugenol (100 mg/ kg) and control group (group 7), equal volume of norma! saline was injected intraperitonealy . The minutes 0-5 and 16-60 were considered as acute and chronic phases of pain in the formalin test, respectively. Data were statistically analyzed by ANOVA and Tukey's tests.
Results: The results showed that local injection of eugenol to the same paw receiving formalin caused a decrease of nociception in both acute and chronic phases of formalin test (PO.005). However, in the group that eugenol (50mg/ kg) was injected to the contralateral paw, no significant differences were observed in the pain score in comparison with the control group. Intraperitoneal injection of eugenol (lOOmg/kg) did not reduce the nociception in the acute phase, but it caused a significant decrease of nociception in tonic phase (PO.00I).
Conclusion: It was concluded that eugenol, as a local anesthetic drug not only inhibits nociceptive impulse conduction on the peripheral pain fibers, but also centrally reduce chronic pain.
M. Ghavamnasiri , Saa. Hosseini , H. Farzaneh ,
Volume 16, Issue 1 (4-2003)
Abstract
Statement Problem: A few studies have been conducted about bioglass posts.
Aim: The aim of this study was to compare bioglass posts with prefabricated metallic posts in clinical performance of extensive composite restorations for anterior endodontically treated teeth.
Materials and Methods: Sixty endodontocally maxillary anterior teeth, with horizontally or vertically destruction, were selected. Teeth were divided into two groups based on the kind of post: Metallic prefabricated parapost and bioglass post. Each group was divided into three subgroups based on anterior bite: normal, deep bite and edge to edge. Gutta-percha was removed from 2/3 of canal length for parapost and 1/3 for bioglass post. After etching with phosphoric-acid (37%) and applying dentine bonding syntac, Duo cement was used for the adhesion of bioglass post and a self cured composite (Degufil) for parapost. Restoration was done with a hybrid composite (Heliomolar). Follow up studies, radio-graphically and clinically, were done every three months for a 1.5-year period. Exact Fisher and Pearson tests were used for data analysis.
Results: Apical lesion was not observed in any of the radiographs. Post seal was increased by resin cement and dentin bonding agent. Post type did not significantly affect on the clinical success rate of the restorations. The retention of restoration, for both posts, was the same. Crown destruction had no significant effect on success rate. The type of anterior bite had a significant effect on success rate, as the total 6.6% failure rate was related to the patients with anterior deep bite.
Conclusion: It is suggested to use metallic paraposts and bioglass posts, in extensive composite restorations for patients with deep-bite, more conservatively.
M. Mortazavi , Z. Bahrololoomi ,
Volume 16, Issue 1 (4-2003)
Abstract
Statement of Problem: Microleakage presents the major cause for restorations failure in the oral cavity resulting in postoperative sensitivity, pulp irritation and secondary caries formation.
Aim: The aim of this study was to compare two dentinal adhesive systems of fifth generation and copalite varnish in reducing microleakage of amalgam restorations in primary teeth.
Materials and Methods: In this in-vitro study, 100 class V amalgam restorations were prepared on the buccal or lingual surfaces of primary molar and canine teeth. Samples were randomly divided into four groups (25 samples each). No liner was used for the first group and the second group restorations were lined with copalite varnish. Two dentin adhesives, called Syntac C and Single Bond, were used for the third and fourth groups, respectively. At the next stage, the samples were immersed in 5% fuschin solution for 24 hours, then sectioned buccolingually, and examined under a stereomicroscope for microleakage evaluation.
Results: There was a significant difference between four groups statistically (PO.000I), Comparing four groups, the first and fourth ones, demonstrated the most and the least microleakage, respectively.
Conclusion: The present study showed that new dentinal adhesive systems caused microleakage reduction in amalgam restorations of primary teeth.
A. Khorsand , Y. Soleimani Shayesteh , Ar. Talaci Pour, Ah. Negaresh ,
Volume 17, Issue 1 (4-2004)
Abstract
Statement of Problem: One of the problems associated with the treatment of periodontal diseases is caused through the extension of disease toward furcation area. Several techniques in Conservative, Resective and Regenerative categories have been suggested for the treatment of furcation involvement.
Purpose: The aim of this study was to compare the results of the treatment of grade II furcation involvement in mandibular molars using an allograft material named 'Dynagraft' (a type of demineralized bone matrix) and the coronally positioned flap.
Materials and Methods: In this randomized controlled clinical trial study, twelve patients (9 females and 3 males), aged 25 to 40, suffering from bilaterally grade II furcation involvement of mandibular molars who referred to dental faculty Tehran University of medical Sciences, were investigated. The molars of one side were treated by Dynagraft whereas those of the opposite side underwent the CPF method. Measurements of the probing pocket depth (PPD), clinical attachment level (CAL), keratinized gingiva (KG) and horizontal probing depth (HPD) were recorded at baseline, 3 and 6 months after surgery. In order to investigate the bone radiographic changes, radiovisiography at the mentioned periods in addition to clinical investigation, were performed. For statistical analysis, Paired West was used.
Results: The mean PPD reduction three months and six months after the operation were 1.75 mm and 2.25mm, respectively in the Dynagraft (test) group whereas 1.26mm and 1.27mm in the CPF (control) group (P<0.005). The mean attachment gain three months and six months after the operation were 1.1 mm and 1.5mm respectively in the test group, and 0.2mm and 0.3mm in the control group (P<0.005). The mean KG reduction three months and six months after the operation were 0.5mm and 0.6mm respectively in the test group and those of the control group were 1.1mm and 1.1mm. The mean HPD reduction three months and six months after the operation were 1.55mm and 2mm respectively in the test group (P<0.005) and 0.55mm and 0.55mm in the control group (PO.01). Radiovisiography of the mentioned areas three months and six months after the operation confirmed the changes obtained from clinical measurements, showing appreciable reconstructive results (Bone filling) in the test group as compared with the control group. Moreover, root resorption was not observed.
Conclusion: Based on the results of this study, Dynagraft can be used as an appropriate material in the treatment of grade II furcation involvement in mandibular molars. However, for a through evaluation of such regenerative techniques in furcation involvement, further studies with larger population and long term follow up in addition to histologic studies are suggested.
M. Ghavam Nasiri , R. Goharian , A. Madani , T. Salari,
Volume 17, Issue 2 (6-2004)
Abstract
Statement of Problem: Parafunctional habits are the most important factor in the creation of non-carious cervical lesions and correcting of these habits may affect cervical lesions.
Purpose: The goal of this study was to survey the effects of one-year occlusal adjustment on clinical success of non- carious cervical restorations.
Materials and Methods: In this clinical study, sixty tooth-colored cervical restorations on canines and premolars in patients with parafunctional habits (bruxism and clenching) were studied. The teeth, according to the type of restorative material, were randomly divided into two groups: One group with a composite resin (Tetric Flow Group A: n=30) and the other group with a compomer (Compoglass Flow Group B: n=30). After restoration, each group was divided into two subgroups: (A1, B1) with occlusal adjustment (case group), (A2, B2) without occlusal adjustment (control group). The evaluation was perfumed single blind at 6 and 12 months after restorative operations according to Us Public Health Service (USPHS) classification. Assessment criteria included: marginal integrity, marginal discoloration, recurrent caries, postoperative sensitivity and loss of filling. Statistical analysis was completed using Fisher’s exact test.
Results: In 12 month period between two groups of compoglass Flow restorations, group B1 showed superior results than group B2, however, no significant difference was found between both groups of tetric flow restorations (A1 and A2). There was also no difference in clinical conditions between A2 and B2 groups.
Conclusion: Considering the results of this study, it can be concluded that occlusal adjustment puts a considerable effect on clinical success of compoglass non- carious cervical restorations. However, it should be mentioned that such and effect was not found among Tetric flow restoration.
Mb. tavakoli , R. Tabarak , A. zargar ,
Volume 17, Issue 4 (1-2005)
Abstract
Statement of Problem: Zinc contained cements are so important among dental material as they have many indications and used in different ways therefore evaluation of their physical properties is so important in dentistry.
Purpose: The purpose of this research was to measure some physical properties of zinc-contained cements used in restorative dentistry. These cements included: Zinc oxide-eugenol, Zinc phosphate and Zinc polycarboxylate. Physical properties measured in this research were compressive strength, and setting time also Solubility & Disintegration were evaluated.
Materials and Methods: To perform this research two packs of each cement type were provided from an Iranian company products as prototypes and German HARVARD Dental GmbH company products as proof samples. For compressive strength 11 samples provided from any type of cement. For setting time test, 16 samples provided from Zinc oxide-eugenol and 11 samples from two other types. For solubility &
disintegration beet, 11 samples provided only from Zinc oxide-eugenol cement. The results compared with standard.
Results: The results of Iranian product showed that compressive strength of Zinc oxide-eugenol- is I2.58±3 MPa, of Zinc phosphate cement is 37.2I±5.0 MPa and of Zinc polycarboxylate cement is 35.86±2.1 MPa.Setting time of Zinc oxide-eugenol cement is 2 9.04 ±0.7 1 min, of Zinc phosphate cement is 5.41 ±0.55 min and of Zinc polycarboxylate cement is 2.5±0.6 min. Solubility & disintegration of Zinc oxide-eugenol cement is 8.44±i.l%. None of these findings are in standard limit.
Conclusion: By the use of standard charts it is concluded that: Only compressive strength of Zinc oxide-eugenol cement is between standard limits and compressive strengths of two other types of the cements are less than standard limits. Also only setting time -of Zincoxide eugenol cement is in standard limit and setting times of two other types of the cements aren't in standard limit. The German samples results were in standard limit. Solubility & disintegration-of Zinc-oxide eugenol cement isn't in standard limit. Therefore it is concluded that all types of these cements are not standard for use.
N. Eshghyar , N. Jalayer Naderi , P. Sarraf ,
Volume 18, Issue 1 (3-2005)
Abstract
Statement of Problem: Odontogenic keratocyst is a developmental odontogenic cyst which arises from dental lamina. One of the important features of odontogenic keratocyst is strong tendency to recurrence.
Purpose: The purpose of this study was the statistical evaluation of age and gender of patient as well as area of involvement in odontogenic keratocysts in the oral and maxillofacial pathology department of dental faculty of Tehran University of Medical Sciences from 1971-2002. Materials and Methods: This study was a cross sectional, descriptive one. Medical records were reviewed and variables such as age, gender and site of involvement were recorded. The data were analyzed with SPSS software.
Results: The relative frequency of odontogenic keratocyst was 36%. 66% of cysts were in men and 34% in women. 68% of lesions affected the lower jaw and 32% the upper jaw. Regarding the site of involvement, 48% of lesions involved the molar region of mandible and 42%, the anterior part of maxilla. The occurrence of keratocysts was higher in this sites. Most of the cases were diagnosed in the third decade.
Conclusion: Based on the findings of this study, odontogenic keratocyst was more prevalent in men, mandible and the third decade. The posterior part of mandible and anterior region of maxilla were involved most frequently.
Sh. Shahrabi , S. Moosavi Rad ,
Volume 18, Issue 2 (5-2005)
Abstract
Statement of Problem: Epulides Fissurata (EF) are common proliferative and denture- induced lesions of the oral cavity with a predilection for female. This suggests a possible role for sex steroid hormones in the development and progression of these lesions.
Purpose: The objective of this study was the immunohistochemical evaluation of epulis fissuratum of the oral cavity for estrogen and progesterone receptors expression in epithelial, stromal, inflammatory and endothelial cells populations.
Materials and Methods: In this cross-sectional study, 15 samples of formalin- fixed, paraffin- embedded epulis fissuratums including marginal mucosal tissues in 4 cases as a control group, were immuno-histochemically evaluated for estrogen and progesterone receptors protein expression.
Result: In 10 cases, estrogen receptor positivity was found within the epithelium and progesterone receptor immunoreactivity was present in 7 cases. Stromal cells exhibited estrogen and progesterone receptor immunostaining in many cases but only few cases showed expression of these receptors in the inflammatory and endothelial cells. Estrogen and progesterone receptors were also detected in some cases containing salivary glands tissue.
Conclusion: Although chronic irritation may be the initiating factor for the occurence of epulis fissuratum, some of the cells in the lesion, could be potential targets for estrogen and progestrone hormones.
