Showing 21 results for Abadi
M. Saheb Jami , M. Eslami Amirabadi ,
Volume 5, Issue 1 (9 1992)
Abstract
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AR-SA The following reports are introducing 3
patients with progressive systemic sclerosis who had oral manifestations such
as limited mouth opening, PDL thickening,... as well as uncommon internal
resorption in many of their teeth with any etiologic factor. According to oral
manifestations of systemic sclerosis, It seems that internal resorption can be
associated to their systemic disease.
F. Haghighati , Sh. Nezam Abadi ,
Volume 12, Issue 3 (10 1999)
Abstract
Bacteria! plaque is an essential factor of gingival and periodontal disease.The ability of chemical piaque control agent to prevent plaque formation is well documented compare with other mechanical plaque removal methods. The purpose of this study was to compare clinical effects of Shore choice mouth rinse (H2 O2, 0.1%) with a placebo.Following a period of 4 weeks, 20 subjects were allocated to two treatment groups.During this period of time, they rinsed twice a day with either a placebo mouth rinse or the Shor choice.Plaque Index (PI) and bleeding on probing index (BOP) were recorded three days after scaling and root planning. These indecies were rechecked 2 and 4 weeks after rinsing the subject's mouth by mouth rinse and placebo. Results indicated that although there were no significant differences between test and control groups, a reduction of PI and BOP were found in different stages of this study.The clinical data obtained in this study are thus consistent with the previous data, however, care should be taken to extrapolate these results.
Mh. Samandari Najafabadi , Sh Shahrabi Farahani , H. Kheirollahi ,
Volume 20, Issue 2 (9 2007)
Abstract
Background and Aim: One of the complications following major oral surgeries is mucosal defects and delayed healing process. Up to now, various mucocutaneous grafts have been used in this field and recently, amniotic membrane has been proposed as a biological dressing in dermatologic, ophthalmologic and otolaryngologic practices. The purpose of this pilot study was to evaluate the healing process following human amniotic membrane graft on oral keratinized mucosa of rabbit.
Materials and Methods: In this experimental animal study, two surgical mucosal defects with the same size were made in palatal mucosa of 10 rabbits with the same weight, gender and race and a graft of human amniotic membrane was used on one of the defects. On the 7th, 14th and 28th postoperative days, surgical biopsies were randomly obtained from grafted and ungrafted regions of 3, 4 and 3 rabbits, respectively and submitted for microscopic study.
Results: According to the results, grafted regions showed more surface epithelialization and thicker newly formed epithelium. Also inflammatory cells infiltration was less in these areas. In all cases, there was a remarkable cartilage formation in the connective tissue of the recipient sites.
Conclusion: The results of this study suggest that the use of amniotic membrane graft in oral surgery could be effective in healing process. Additional studies should be done using animal and human models with more samples. Furthermore, the formation of cartilage in the grafted sites and its possible potential in reconstruction of bone defects, needs to be studied.
Gh. Eslami Amirabadi, S. Mahvidizadeh, M. Nasiri,
Volume 24, Issue 1 (23 2011)
Abstract
Background and Aims: The aim of this in vitro study was to compare shear bond strength of metal brackets bonded to dental porcelain on the basis of presence or absence of silane, type of acid [hydrofluoric acid (HF) or phosphoric acid (H3PO4)] and roughness of porcelain surface (glazed or deglazed) within mouth-like environment.
Materials and Methods: Eighty glazed ceramic disks were randomly divided into 8 groups of 10 disks: group 1 [HF+silane], group 2 [deglazed+HF+silane], group 3 [HF], group 4 [deglazed+HF], group 5 [H3PO4+silane], group 6 [deglazed+H3PO4+silane], group 7 [H3PO4], group 8 [deglazed+H3PO4]. Then the brackets were bonded and thermocycled. After that, shear bond strength test was done using the Zwick device and the type of bond failure was determined under stereomicroscope at 4X magnification. 3-way ANOVA and Kruskal-Wallis were used for statistical analyses.
Results: The shear bond strength for the test groups were as follows: group (1):13.05±7.7 MPa , group (2):25.16±10.66 MPa, group (3):6.7±5.86 MPa, group (4):15.39±8.97 MPa, group (5):12.76±7.91 MPa, group (6):13.57±7.85 MPa, group (7):0.54±0.67 MPa, group (8): 9.34±6.52 MPa. The type of bond failure in all groups was adhesive failure except for group 2. No significant difference in the interaction between (glazed or deglazed), (presence or absence of silane), and type of acid was found (P>0.05).
Conclusion: Under the conditions of this study, the best clinical method was the use of 37% phosphoric acid and silane that resulted in the optimal clinical strength and adhesive bond failure.
Jalil Modaresi, Mahdi Dastorani, Fazlolah Soleymani Najafabadi, Fatemeh Ezodini,
Volume 25, Issue 1 (7 2012)
Abstract
Background and Aims: Radiographic examination is a necessary step in diagnosis of horizontal root fracture. The purpose of this study was to determine the sensitivity and specificity of single radiograph for detection of horizontal root fracture.
Materials and Methods: In this analytical-descriptive study, 30 human freshly extracted teeth were used. Using a hammer and clamp, the teeth were divided into two sections accidentally and then sections were attached together by cyanoacrylate glue. Two radiographs were taken with and without a piece of human mandibular bone. Afterward, radiographs were analyzed by three expert dentists using a slide show device.
Results: The diagnostic sensitivity and specificity of single radiograph for detection of horizontal root fracture without bone was 100%, but in radiographs of teeth with bone was 82.7% and 100%, respectively.
Conclusion: Based on the results of this study, in most cases, the horizontal root fractures can be detected by a single periapical radiograph.
Fahimeh Mokhtari, Amir Mohamad Mahabadi, Naieeme Ghafarian, Alireza Ghate, Alireza Razavi,
Volume 25, Issue 1 (7 2012)
Abstract
Background and Aims: Working length determination and remaining this length is of great importance in root canal therapy. Recently, electronic apex locators are being used to determine working length and decrease the number of radiographs. The purpose of this study was to compare the sensitivity of Root ZX and Novapex electronic apex locators with radiography in a clinical study.
Materials and Methods: In this study, 73 single-canalled teeth of the patients referred to the endodontic department of the Yazd Dental School were evaluated. The access cavity was prepared and working length of the root canals were measured by using the apex locators: Root ZX and Novapex. The file was placed in the root canal and a periapical radiograph was taken using parallel technique. The working lengths obtained by apex locators were recorded and compared with those of radiographs. The data were analyzed by Pearson's correlation coefficient, Wilcoxon test and paired t-test.
Results: The exact measurement without any fault was 46.6% for Root ZX and 20.5% for Novapex compared to radiography. In the range of 0.5 mm fault, the results were 91.8% for Root ZX and 64.4% for Novapex compared to radiographic measurements. The difference between the average of the measured lengths by Root ZX and radiography was not significant (P=0.17). On the other hand, the results showed significant difference between the average of the measured lengths by Novapex and radiography (P=0.017). The difference between two apex locators was not significant (P=0.061).
Conclusion: Root ZX and Novapex with high accuracy are useful for determining working length of the root canals in pregnant patients with special anatomic conditions and patients with muscle disharmony. Therefore, the use of these apex locators combined with radiography is recommended in root canal treatment.
Tahereh Sadat Jafarzadeh Kashi, Mohammad Erfan, Akbar Fazel Najafabadi, Seied Mostafa Fatemi, Marjan Behroozibakhsh, Haleh Hali, Hosein Bagheri Gorgani,
Volume 25, Issue 2 (9 2012)
Abstract
Background and Aims: The aim of this study was to measure the degree of conversion (DC) of three types of composite resins (micro-hybrid, nano-hybrid and Ormocer) with different light curing units (LED LCU and QTH LCU) in two depths.
Materials and Methods: Three commercially available dental resin composites were used in this study: (Tetric Ceram, Ivoclar Vivadent, Liechtenstein-A2 shade), (Tetric Evoceram, Ivoclar Vivadent, Liechtenstein-A2 shade), (Ceram X, Dentsply, Germany-M2 shade). Specimens were divided into two groups, 5 specimens were photo-activated by QTH unit (Coltolux 75-Colten) and the other five specimens were cured by LED (Demi-Kerr). Then each specimen was sectioned at the top surface and at 2-mm depth. The DC was measured by FT-IR
(Bruker-tensor 27). The data were analyzed by 3-way ANOVA test.
Results: There was significant difference between tested composite resins (P<0.001). The results of top surfaces were significantly different from those observed at 2-mm depth (P<0.001). The type of curing unit affected the polymerization of Ceram X resin composite.
Conclusion: This study showed a significant difference in the degree of conversion in different thicknesses within three groups of resin composites.
Jalil Modaresi, Amir Reza Heshmat Mohajer, Hossein Aghili, Morteza Khorshidi, Faramarz Rostami Chavoshlo, Amirmohamad Mahabadi,
Volume 25, Issue 3 (1 2012)
Abstract
Background and Aims: Electric pulp testing is used for diagnosis of the pulp status. This test is technique sensitive and hence may elicit positive or negative false response in case of inaccurate use. The optimal site for placement of the probe tip has not been determined. The aim of this study was to evaluate the effect of pulp tester probe placement site on the response of maxillary teeth.
Materials and Methods: A total of 378 teeth (126 central incisors, 126 lateral incisors and 126 canines) in 67 voluntary 20-35 year-old patients were selected. Three sites on each tooth (incisal edge, labial and lingual surfaces) were tested with an electrical pulp tester and responses were recorded. Data were analyzed by Repeated Measure ANOVA test.
Results: The central teeth showed significantly lower sensation threshold than lateral and canine teeth (P<0.001). The incisal edge of tooth were significantly more sensitive compared to labial and lingual surfaces (P=0.008).
Conclusion: This study showed that the optimum site for placement of pulp tester probe was incisal edge.
Hossein Afshar, Ahmadreza Shamshiri, Vahid Pourtalebi Firozabadi, Zahra Bani Ameri,
Volume 25, Issue 4 (9 2013)
Abstract
Background and Aims: Nursing Caries (NC) is a destructive form of caries because of incorrect nutritional habits in infants that affects deciduous teeth after eruption. Familiarity with the pattern of this type of caries and evaluation of its symmetrical or asymmetrical pattern is necessary for effective and scientific diagnosis and treatment. The aim was to assess the symmetrical or asymmetrical aspects of Nursing Caries in children between 3-5 years old.
Materials and Methods: In this cross-sectional study, 10 kindergartens were randomly selected by the Tehran Welfare Organization. 115 children with NC caries entered to study after examination. Written consents were obtained from the parents. The dmfs in upper primary incisors and upper and lower primary canines, as well as the first primary molars were assessed and the caries pattern in terms of symmetrical or asymmetrical aspects was evaluated. The data were analyzed by ANOVA, LSD, Chi-square and Fisher tests.
Results: In 53.9% of the children with NC, the anterior teeth were affected symmetrically, while 46.1% indicated an asymmetrical pattern. In general, 32.2% of the teeth were affected in a symmetrical pattern and 67.8% of them in an asymmetrical pattern. About the relationship between the breastfeeding from the right or left breast and the symmetrical pattern of the NC, 51% of the children were equally breastfed from both breasts. However, in the asymmetrical NC pattern with more impact in the right side of dentition, 50% of the children had been breastfed from the left side and in children with more caries in the left side of dentition, 50% of them had been breastfed from the right side (P=0.01).
Conclusion: NC has symmetrical and asymmetrical patterns. Direction of mother for breastfeeding affects the symmetrical and asymmetrical pattern of NC.
Haghgoo Roza , Rezvani Mohammad Bagher , Haghgoo Hamid Reaza , Ameli Nazila , Zeinabadi Mehdi Salehi ,
Volume 27, Issue 4 (1-2015)
Abstract
Background and Aims: Dental caries is one of the most common infectious diseases which could be prevented in various ways. The aim of the present study was to evaluate the effect of a toothpaste containing different concentrations of nano-hydroxyapatite on the remineralization of incipient caries.
Materials and Methods: 9 sound first premolar teeth of maxilla and mandible were sectioned to four pieces. 6 specimens were stored in distilled water as control group. The remaining 30 specimens were demineralized for 72 hours and then their microhardness was measured. 0, 0.5, 1, 2 and 5% wt nano-hydroxyapatite were added to the solution of distilled water and toothpaste. Specimens were divided into 5 groups (N=6) and after demineralization, each group were randomly immersed in the above-mentioned solutions for 15 minutes. Next, specimens were kept in artificial saliva for 1 hour followed by immersion in the related remineralizing solution for another 15 minutes. This procedure was repeated for 5 days. Finally, the microhardness of the teeth was measured. Data were analyzed using repeated measures analysis of variance (ANOVA).
Results: The microhardness of demineralized teeth was increased following exposure to different concentrations of nano-hydroxyapatite, but this increase was not statistically significant (P=0.62).
Conclusion: Nano-hydroxy apatite can enhance remineralization and increase the tooth microhardness although this increase was not significant.
Fatemeh Mokhtari, Amir Hossein Mansor Abadi, Ali Gharaati Jahromi, Ehsan Anvar, Zandi Hengame, Tabrizi Zade Mehdi, Taghavi Mayam,
Volume 28, Issue 3 (10-2015)
Abstract
Background and Aims: Bacteria and their products have a major role in pulp and periapical diseases. The purpose of this study was to compare the antimicrobial activity of sodium hypochlorite, iodide potassium iodide and chlorhexidine on the enterococcus faecalis after root canal filling.
Materials and Methods: In this experimental study, 95 single canal human teeth were collected. Then after washing and cleaning and filing, the sterilization done using an autoclave. The teeth were smeared with enterococcus faecalis except five which selected as controls and then divided them into 3 groups which A randomly represented the irrigation by sodium hypochlorite, iodide potassium iodide (IKI) and chlorhexidine solution were done. The teeth were filled with gutta-percha and then incubated in a incubator for 90 days at a temperature of 37° C. The specimens were analyzed for Colony Count. Data were analyzed using Kruskal-Wallis test and Chi-Square.
Results: According to the results of this study, the correlation between the 3 groups of cultured teeth were not significant (P=0.812).The specimens which were washed by IKI had the most positive amount of cultures (23.3%) and the specimens which washed by chlorhexidine had the lowest (16.7%).
Conclusion: The results of this study showed that after the use of different wash solutions, no statistically significant difference exist in their antimicrobial activity after root canal therapy.
Saeed Nemati Anaraki, Hamed Karkehabadi, Nazanin Zeinab Garshasb Zadeh,
Volume 29, Issue 1 (7-2016)
Abstract
Background and Aims: Microleakage is one of the most common problems in bonding systems, which cause different clinical shortcomings such as post operative sensitivity, marginal discoloration and pulp necrosis that can decrease those using bonding systems. The aim of this study was to compare the microleakage of three self etch bonding agents (generation 6 and 7) in class 5 composite cavities.
Materials and Methods: In this experimental study, 30 facial class 5 cavities were prepared in 30 human premolar teeth which were freshly extracted for orthodontic purposes. Cl V cavities were prepared in 2*3*2 mm dimensions. Occlusal margins were in enamel and gingival ones in cementum and randomly divided into 3 groups of 10 each. Then the cavities were treated by clearhil SE Bond (Kuraray, Japan), G Bond (GC, Japan), and Opti Bond Solo Plus (Kerr, USA), according to the manufacturers’ insductions. Then the cavities were filled using Z100 resin composite. The specimens were then immersed in a 50% AgNo solution for 24 hrs. Then, the teeth were cut buccolingually to be evaluated for dye penetration with stereomicroscope. Data were analyzed using Kruskal-Wallis test.
Results: This study revealed that Opti bond solo plus had type1 microleakage (dye penetration up to 1/3 of cavity) in 80% of specimen, and type 4 microleakage (along axial wall) in 10%. Clearfil SE bond had no leakage in 50%, type1 in 40% and type 2 (up to 2/3 of cavity) in 10%. But there was no significant difference in the microleakage at the gingival margins between 3 groups (P>0.05).
Conclusion: Clearfil SE Bond and G bond could prevent microleakage more effectively than that of Opti Bond Solo Plus on the occlusal margins. However, no difference in the microleakage on the gingival surfaces was found.
Abbas Majdabadi, Mona Ahadi, Reza Fekrazad,
Volume 29, Issue 1 (7-2016)
Abstract
Background and Aims: Nowadays lasers are used as alternatives to the tooth preparation because of reducing pain and bloodshed. The aim of this study was to observe the effect of ArF laser on the dental hard tissues.
Materials and Methods: For this research human molar teeth with no caries or dental restoration and enamel cracks were used. Irradiation laser energies were taken 95, 70 and 50 mJ for enamel and 80, 70 and 50 mJ for dentine. Then, for each of energy values pulse numbers (repetition rate) were adjusted at 200, 400, 600, 800, 1000 and 1500. Ablation was carried out without water spray on both enamel and dentine. Finally, the dimensions of ablated areas were measured by using a camera connected to the computer and results were applied in graphs.
Results: For each energy value, the ablation dimension increased by increasing pulse numbers. Ablation depth in dentine was more than that of for enamel. Trends of graphs for dentine and enamel were the same. SEM images of ablations by 95 mJ energy on enamel and 80 mJ energy on dentine showed sharp edges.
Conclusion: Ablation depths increased by increasing pulse numbers, for each energy level. However, this increase was not that as expected, because the lack of water spray while irradiating.
Abbas Majdabadi, Mona Ahadi, Reza Fekr Azad,
Volume 29, Issue 2 (11-2016)
Abstract
Background and Aims: Nowadays lasers are used as alternatives to the tooth preparation because of reducing pain, bloodshed and stress. The aim of this study was to observe the effect of Er,Cr:YSGG laser on the dental hard tissues.
Materials and Methods: For this studty, molar teeth with no caries or dental restoration and enamel cracks were used. The laser power were taken from 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 up to 6 Watts for enamel and 0.5, 1, 1.5, 2, 2.5, 3, 3.5 and 4 Watts for dentine simultaneously with water spray. The ablation effect was observed on both enamel and dentine. Finally, by use of a CCD camera connected to the computer, the dimensions of ablated areas were measured and results were applied in graphs.
Results: Volume of ablation was increased by increasing laser power. Also, by increasing energy value in each stage, the depth of ablation was increased for enamel and dentine. SEM images of ablations by 3.5 and 4 Watts on enamel and 1 and 1.5 Watts on dentine did not show any sharp edges.
Conclusion: The ablation volumes and depth increased by increasing the energy of laser pulses power. The reason for this trend was due to the water spray while irradiating and good absorption of water by laser beam.
Roghieh Aliakbari, Mohammad Vahedian-Shahroodi, Hadi Tehrani, Habibollah Esmaeili, Rajabali Hokmabadi,
Volume 31, Issue 1 (6-2018)
Abstract
Background and Aims: The dentistry profession is one of the most injuring professions that causes most pains and hurts for dentists because of their lack of knowledge about the ergonomic position through the work. The purpose of this study was to assess the ergonomic position of dentists with RULA method in dentists of Bojnord.
Materials and Methods: In this cross-sectional study, all of the Bojnord’s county dentists were selected. RULA method and Nowerdik questionnaire were used for investigating the agronomical position, and muscular-skeleton position, respectively. The analysis was done by SPSS22 using regression and chi-square test. A P-value of less than 0.005 was assumed as significant.
Results: The most muscle-skeleton reports were 55.6% (35 persons) related to back, 54% (34 persons) related to shoulders, 50.8% (32 persons) related to waist, and 47.6% (30 persons) related to neck aches. In the last 12 months, 90.5% of dentists reported pains from at least one of organs of their bodies and 27% were supposed to leave their works which the sex (P=0.84), length (P=0.75), and weight (P=0.38) were not significantly related to this case.
Conclusion: According to the results of this study educational interventions is essential to prevent the musculoskeletal disorders in dentistry.
Bahram Kouhnavard, Hosseinali Mahgoli, Somayeh Bolghanabadi, Mohsen Yazdan Aval, Maryam Rostami Aghdam Shendi, Malihe Kolahdouzi,
Volume 31, Issue 2 (9-2018)
Abstract
Background and Aims: Making dental prostheses is sensitive and accurate work and requires powerful and skilled hands. Because of this, the dental prosthesis technicians may suffer harmful effects such as stress and fatigue during the course. The aim of this study was to investigate fatigue, stress and job performance and their relationship with some demographic variables in this community.
Materials and Methods: The present study was cross-sectional and done in 2016. The study population was a group of dental prosthesis technicians that had participated in a national congress in Tehran. Sampling was done by census Two standardized questionnaires on the subjects of fatigue and stress which were distributed among 100 female and male participants and sampling was done by census. Then, the obtained data was analyzed using SPSS16 software and applying descriptive statistics, Pearson correlation test, and ANOVA, T-test.
Results: From the 100 samples, there were 16 females and 84 males with mean age 34.71±7.90 and average work experience of 10.82± 9.01 years. 82 percent of the subjects were married and 42 percent of them were smokers. The results showed that 100 percent of dental prostheses technicians were facing with moderate to severe stresses. The stress and fatigue scores in married ones were higher than the single ones. The results showed a significant relationship between smoking, stress, and fatigue scores (P<0.05).
Conclusion: According to the high level of job stress in the dental prostheses technicians, this problem must be considered, minimized, and more attention should be paid to their psychological and emotional problems.
Md Mahdi Kashani Aragh Bidi, Dr Mahdi Jabari Jahromi, Dr Sepide Bagheri Hosein Abadi, Dr Mohammadreza Shokuhifar,
Volume 33, Issue 1 (7-2020)
Abstract
Background and Aims: The vertical growth pattern of the face depends on several factors. One of these factors can be the muscle strength of the jaw. Maximum occlusal force (MOF) can be considered as an index to measure the function of the muscles of the masticatory system. Despite the various studies, the relationship between the facial pattern and muscle function is still controversial. According to soft tissue paradigm theory, muscle can affect the shape and form of bones of the jaw, face and head. The aim of this study was to determine the relationship between the maximum occlusal force and head and face growth pattern in dental students of Shahed University in Tehran.
Materials and Methods81 dental students (40 males and 41 females) were participated. MOF was measured with a loadcell designed for this purpose, and the anthropometric points of the face and head were measured with digital caliper. Two-way ANOVA and Tukey HSD tests were used to determine the effect of facial and head patterns on the maximum occlusal force. Statistical analysis was performed by SPSS23.
Results: The mean MOF in males was 480 N and in females 320 N. Head forms in our sample research were 54.32% Brachycephale, 32.09% Mesocephale, and 13.58% Dolicocephale. The form of the face was 23.45% euprosopic, 39.5% mesoprosopic, and 37.03% leptoprosopic. According to the statistical analysis, the relationship between the maximum occlusal force and leptoprosopic form of face was statistically significant (P=0.02). However, there was not significant relationship between the maximal occlusal force and none of the three type of head forms (P=0.813).
Conclusion: MOF was related to the leptoprosopic pattern of face, and these individuals had less bite power. No relationship between the maximum occlusal force and head forms and neither between the head pattern and facial pattern was found in this study. The maximum occlusal force in men was higher in all three facial patterns than that of women, although this relationship was not significant.
Ehsan Aliabadi, Esfandiar Keshavarz,
Volume 33, Issue 1 (7-2020)
Abstract
Background and Aims: The inferior alveolar nerve block (IANB) is the most frequently used technique for mandibular anesthesia. Due to the many factors which can cause its failure, the aim of this study was to evaluate the efficacy of experience and knowledge in the success rate of IANB technique.
Materials and Methods: : In this study, 115 students of Shiraz Dental school were participated in two groups. One group contained 53 novice students and another group 62 students with one year experience in IANB injection. Each student accomplished injection once and then success or failure of the injection was examined. In order to evaluate the students’ knowledge, each student was asked to fill out a questioner including 6 questions related to the instruction of the injection. Data were then collected, coded, and analyzed by SPSS18 using Chi square with a significant level of 0.05.
Results: The rates of knowledge in novice and experienced group were 71.6% and 86.3%, respectively. The success rates of IANB were 47.1% in novice group and 64.3% in experienced group. The success rates of IANB and knowledge were significantly higher in the experienced group compared with the novice group. (P=0.02 and P=0.01, respectively) There was no significant difference between male and female (P=0.06).
Conclusion: The results showed that knowledge and experience could play an important role in the success rate of IANB technique.
Ali Mohammad-Hoseini, Maryam Pirmoradian Najafabadi, Gholamreza Eslami Amirabadi, Mehdi Aragh Bidi Kashani,
Volume 33, Issue 1 (7-2020)
Abstract
Background and Aims: Elastomeric chains are known as a current device with the purpose of dental movement in orthodontic treatments. The aim of this study was to compare the elastomeric behavior and force degradation rate between different elastomeric chains existing in Iran in different time durations.
Materials and Methods: 11 different elastomeric chains used in this study were: Class One, ASTAR, G&H, TSNPT, MIB (French and Chinese type), Ultra Chain and both American, Ortho Technology (simple and memory type). All chains were stretched upon to exert 150 g force and then force degradation rate in 6 time duration
(1, 3, 24 hours and 3, 7, 21 days) and modulus of elasticity (MOE) in 2 time duration (start and 21 days) were investigated. All Data were analyzed statistically by ANOVA, Tukey, Games-Howel tests.
Results: All chains up to the 21th day showed a significant decrease in MOE except for the G&H, ClassOne, simple orthotechnology and a significant force degradation except for the American (memory type). The most significant force degradation rate was in ASTAR gray (P<0.05) and the least in MIB (French), Ultra Chain, and American (P<0.05).
Conclusion: All chains showed significant time-dependent force degradation (mostly in the first day). Only, this rate was not significant in any time duration for the American (memory). In all groups, the most force degradation rate belonged to ASTAR gray and the least to Ultra Chain, MIB (French) and American after 21th day.
Elya Ranayi, Fatemeh Rahmatzadeh Yousefabadi, Saber Babazadeh, Ali Kazemian,
Volume 35, Issue 0 (5-2022)
Abstract
Background and Aims: The aim of this study was development and validation of a questionnaire measuring the pseudo-scientific unsupported of Iranians’ belief regarding oral health.
Materials and Methods: A list of 169 pseudo-scientific and invalid Iranian beliefs about oral health that was collected in the previous phase of the study were sent to a purposive sample of 13 professors at Mashhad dental school which resulted in extracting 34 beliefs being considered more common among Iranians. A list of 21 pseudo-scientific beliefs was obtained for preparing the questionnaire after receiving the sample opinions of 21 professors of Mashhad dental school about the invalidity and pseudoscientific propositions and their written revision. Finally, the questionnaire was completed by 44 participants to analyze the ease and clarity and to calculate Cronbach's alpha and Kuder Richardson measure as a homogeneity reliability index. It was completed in a group of 15 participants with a time interval of one month for test-retest analysis and consistency reliability evaluation.
Results: A questionnaire consisting of 21 beliefs was developed using four-point, three-point, or two-point Likert scales. The standardized Cronbach's alpha score and Kuder Richardson's measure score were 0.641 and 0.514, respectively, which indicated the moderate to good reliability of the homogeneity. The Interclass Correlation Coefficient (ICC) was calculated as 0.863, representing very good reliability of consistency of the questionnaire. Furthermore, the kappa coefficient of each of the 21 statements had a significant difference with zero (P<0.05) ranging between 0.605 and 1.
Conclusion: The result of the present study is a questionnaire measuring the level of Iranians’ belief in unsupported and invalid statements about oral health. Using this questionnaire would be helpful for dentists and oral health professionals to promote knowledge of Iranians about oral health.
