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Dental Materials and Techniques - Volume:6 Issue: 1, Winter 2017

Journal of Dental Materials and Techniques
Volume:6 Issue: 1, Winter 2017

  • تاریخ انتشار: 1395/10/18
  • تعداد عناوین: 8
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  • Amini Parviz, Amin Rahpeyma, Maryam Hejazi * Pages 1-6
    Statement of the Problem: Understanding about impression materials, their properties, uses and manipulation can guide operators towards having more successful restorations.
    Purpose
    The aim of this in vitro study was to compare the accuracy of a condensation silicone impression material, Optosil, and an addition poly siloxane impression material, Elite-HD.
    Materials And Method
    A laboratory model with two metallic dies was used to make impression. A horizontal notch on one of the two dies simulated an undercut. Ten impressions were made by each impression material by the putty-wash technique. After pouring impressions with velmix die stone, a total of 20 stone casts were made from both materials. Measurements of casts were compared with the master model. Statistical analyses were performed using t-test.
    Result
    This results of this study showed that the height of die without undercut decreased in both groups. Also the height above the undercut decreased in both groups, which was more obvious in Elite-HD group than Optosil group. The distance between dies increased in both groups, with higher figures for Elite-HD. So, Optosil is a more accurate material for registering inter-abutment distance than Elite-HD. The diameter of die under the undercut decreased in Optosil group and was similar to the master model in Elite-HD. Statistical analysis showed significant differences between these two groups in the distance between abutments (p=0.001), the diameter of die under the undercut (p=0.014) and the height of die above undercut(p=0.057).
    Conclusion
    Optosil is more accurate in registering inter-abutment distance than Elite-HD, so Optosil is preferred for fixed partial denture impressions. Since Elite-HD showed more accuracy in C measurements than Optosil, it is preferred for single crown impressions.
    Keywords: Dimensional Measurement Accuracy, Elastomeric Impression Materials, Polyvinyl Siloxane, Dimensional changes
  • Majid Naser Khaki, Maryam Mohajerfar, Masood Ejlalai, Sara Tvakolizadeh* Pages 7-10
    Background
    The ideal teeth arrangement is an important step for success in complete denture fabrication. There are different methods for determining the posterior denture teeth location. The purpose of this study was the comparison of posterior mandibular teeth location in the study group with Pound or Misch theory.
    Material and
    Methods
    An alginate mandibular impression of 80 dentate patients was taken and poured with dental stone. Retromolar pad area, mesial of canine and the lingual cusps of each posterior tooth marked on the cast and then transferred to the graded paper. Distance of each lingual cusp from the internal line of Pound triangle was measured. Data were analyzed with SPSS version 16.0.
    Result
    In the study group, the average distance of lingual mandibular cusp from the internal line of Pound triangle was 1.69 mm in first premolars, 0.94 mm in second premolars, 0.7 mm in first molars and 0.75 mm in second molars.
    Conclusion
    In most cases, distance of lingual mandibular cusps was within 1 mm of Pound triangle. Results were more similar to the Pound rather than the Misch theory.
    Keywords: Pound triangle, Misch triangle, posterior teeth
  • Shirin Saravani, Tahereh Nosratzehi *, Sarvar Mir Pages 11-18
    Introduction
    Oral manifestations can be the first signs of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) and a useful marker for the progression of this disease. The present study aimed to determine the prevalence of oral manifestations and examine their relationship with socio-demographic factors in HIV-positive patients in the health centers affiliated to Zahedan University of Medical Sciences (Southeast Iran).
    Methods
    In this cross-sectional study in addition to determining oral manifestations based on the classification of EC-clearing house (European Commission clearing house), information such as age, gender, marital status, residence, education, occupation, habits, oral hygiene, loss of weight in the last six months. Body Mass Index (BMI), mode of HIV transmission, stage of disease, anti-retroviral therapy (ART), and duration of HIV were gathered through direct question from the patients or the information contained in their records. Then the relationship between various factors and oral manifestations was analyzed using Chi-square, Fisher’s Exact Test, Student T Test, Mann- Whitney tests and logistic regression.
    Results
    Oral examination was performed on 119 HIV-positive patients who were 69.7% male and 30.3% female and had a mean age of 35.4±12.7 years. Oral manifestations were found in 57.1% of the patients. Pseudomembranous candidiasis (34.1%) and linear gingival erythema (33%) were the most common lesions in these patients. The probability of oral manifestations occurrence increased with age and duration of smoking in smokers with HIV (P=0.036 and P=0.012, respectively).
    Conclusion
    Most oral manifestations were those strongly associated with HIV infection (91%). Timely diagnosis and treatment of oral manifestations in HIV patients should be considered in conjunction with other treatments.
    Keywords: Human immunodeficiency virus, Acquired immunodeficiency syndrome, Oral manifestation, Oral lesions, Risk Factor
  • Maryam Omidkhoda, Maryam Poosti, Zoha Sahebnasagh*, Seyed Mojtaba Zebarjad, Zahra Sahebnasagh Pages 19-26
    Introduction
    Patients are recommended regular using of mouthwashes to control dental caries or periodontal diseases since orthodontic treatment may have detrimental effects on the tooth structures. However, chemical agents may potentially damage metal components of orthodontic appliances. The aim of this study was to evaluate the influence of three mouthwashes on the surface characteristics of nickel–titanium (NiTi) and Stainless steel (SS) arch wires.
    Methods and Materials: 15 pieces of 0.016 inch NiTi and 15 pieces of 0.016-inch SS wires were randomly assigned into 5 groups including 2 controls (as- received and artificial saliva) and 3 experimental groups. The samples in all groups were stored in artificial saliva in an incubator at 37˚C for one month, after that, the test groups were immersed in Chlorhexidine 0.12%, Hydrogen peroxide 0.12% and Persica mouth washes for 30 min, 1.5 h and 1.5 h, respectively. Then, the samples were washed by distilled water and returned to artificial saliva for more than two months. Surface topography changes and the number of corrosion holes were characterized via a scanning electron microscope (SEM).Two way ANOVA and Tukey tests were used to compare groups.
    Results
    SEM photographs of the present study showed significant corrosion rate among "as- received" group and Persica (p=0.04), Chlorhexidine (p=0.02), and artificial saliva group (p=0.008) in NiTi wires, but there was no significant difference in the surface topography between any of the groups in SS wires.
    Conclusion
    Alterations in surface of NiTi wires were significantly more than SS wires. Although not significant, 0.12% Chlorhexidine and Peroxide showed higher pitting view on SS and NiTi wires, respectively compared to other mouthwashes
    Keywords: Mouthwashes, Nickel, titanium, Orthodontics, Stainless steel
  • Pramita Suwal *, Raj Kumar Singh, Ashok Ayer, Deepak Kumar Roy, Roshan Kumar Roy Pages 27-34
    Aim: To compare the effects of cast partial denture with conventional all acrylic denture in respect to retention, stability, masticatory efficiency, comfort and periodontal health of abutments.
    Methods
    50 adult partially edentulous patient seeking for replacement of missing teeth having Kennedy class I and II arches with or without modification areas were selected for the study. Group-A was treated with cast partial denture and Group-B with acrylic partial denture. Data collected during follow-up visit of 3 months, 6 months, and 1 year by evaluating retention, stability, masticatory efficiency, comfort, periodontal health of abutment.
    Results
    Chi-square test was applied to find out differences between the groups at 95% confidence interval where p = 0.05. One year comparison shows that cast partial denture maintained retention and stability better than acrylic partial denture (p
    Conclusions
    With adequate maintenance of oral and denture hygiene at a regular interval, cast partial denture compared with acrylic partial denture provides better results in terms of retention, stability, comfort and periodontal health of abutment.
    Keywords: Dental prosthesis retention, Denture base, Masticatory efficiency, periodontal health of abutment, Removable partial denture
  • Saede Atarbashi Moghadam, Maedeh Ghorbanpour * Pages 35-39
    Introduction
    Giant cell lesions of the bone comprise a group of jaw bone pathologies. Different pathogeneses such as reactive, vascular or neoplastic have been proposed for these lesions. In addition, differentiating between aggressive and nonaggressive central giant cell granuloma (CGCG) of the jaws based on histopathologic features is still impossible and due to different treatment protocols for the two groups, correct diagnosis is necessary. The purpose of this study was to compare the expression of CD34 between aggressive and nonaggressive CGCGs of the jaws.
    Methods & Materials: This retrospective study was carried out on 16 paraffin blocks in each aggressive and nonaggressive CGCGs group. The expression of CD34 was evaluated with immunohistochemical technique. Afterwards, t-test was used for quantitative evaluation and comparison of CD34 expression among the two groups. Eventually, statistical analysis was performed using Spss20 software. Significance was assigned at p
    Results
    In the present study, the average age of patients in aggressive and nonaggressive groups was 20.93±8.08 and 26.18±16.97, respectively. In both groups, female predilection was observed. Mandible was the most common site of involvement in the aggressive group and the distribution of nonaggressive lesions was equal between both jaws. Although the expression of CD34 in the aggressive group was higher than the nonaggressive group, no statistically significant difference was seen (p=0.15).
    Conclusion
    According to the results of the current study, it appears that CD34 protein cannot be used for identifying the clinical behavior of CGCGs.
    Keywords: Central Giant Cell Granuloma, CD34, Immunohistochemistry, Vascularity, Aggressive, Nonaggressive
  • Reza Imani, Naghmeh Jamaatloo, Maryam Seyedmajidi *, Oveis Khakbaz Baboli Pages 40-43
    Hybrid tumors are very rare tumors composed of two different tumor entities, each of which conforms to an exactly defined tumor category. A 14-year-old boy was referred for an intraosseous painless lesion with a histopathological feature of multiple odontogenic lesions including calcifying odontogenic cyst, complex odontoma and ameloblastic fibro-odontoma. The final diagnosis considered to be a hybrid odontogenic lesion.
    Keywords: calcifying odontogenic tumor, odontoma, hybrid lesion
  • Elaheh Moghim Farooji, Zeinab Kazemi *, Saeed Moradi Pages 44-47
    Tricho-Dento-Osseous syndrome is a rare autosomal dominant disorder. Immunosuppressive drugs, though critical to the treatment, have undesirable effects on patient's healing process. This is a case report of a 10-year-old female, suffering from Tricho-Dento-Osseous syndrome who was under treatment with penicillamine. As the dental treatment was sought too late, both central and lateral incisors on the right side of mandible had severe enamel hypoplasia and tooth necrosis was evident. A large lesion was found in anterior mandible. After proper treatment of the teeth with appropritately considering the systemic condition of the patient, the favorable result was achieved.
    Keywords: Endodontic therapy, Tricho, Dento, Osseous syndrome, Immunosuppressive drug, D, penicillamine