ABSTRACT
Luting cements are necessarily used to increase retention and enhance the marginal seal of fixed partial dentures [FPDs]. In this study, the finite element method [FEM] was used to investigate the effect of different types of luting agents on stress distribution in the luting cement layer in a three-unit implant-supported FPD. A three-dimensional [3D] FE model of a FPD was designed from the maxillary second premolar to the second molar teeth using CATIA V5R18 software, and analyzed by ABAQUS/CAE version 6.6 software. Three load conditions were statically applied to eight points in each functional cusp in horizontal [57.0 N], vertical [200.0 N] and oblique [400.0 N, =120°] directions. Five luting agents including glass ionomer, zinc polycarboxylate, polymer-modified zinc oxide eugenol [ZOE], composite resin and zinc phosphate were evaluated. The stress distribution pattern in the luting cement layer was almost uniform in all luting cements. In addition, the maximum von Mises stress in the luting cement layer [39.96 MPa] was at the cervical one-third of the palatal side of the second premolar when oblique force was exerted on zinc phosphate cement. Moreover, the minimum von Mises stress in the luting cement layer [0.41 MPa] was at the lateral side of the coronal one-third when the horizontal force was applied to the Polymer-modified ZOE cement. Likewise, the luting cement layers in the premolar tooth showed greater von Mises stress than that in molar tooth. The type of luting cement has no significant effect on the stress distribution pattern in the luting cement layer; however, von Mises stress values were different in various types of luting agents. USE of zinc phosphate cement is associated with more limitations
ABSTRACT
An increase in the prevalence of metabolic syndrome [MetS] and type 2 diabetes [T2D] among the obese children is associated with such complications as the early cardiovascular diseases. This study was undertaken to evaluate the frequency of MetS and T2D among the obese children and adolescents in Kashan. This cross-sectional study was carried out on 450 obese children aged 4-18 years in Kashan. Demographic data were recorded for each case and the 12-hour fasting blood samples were collected to determine the total cholesterol, HDL, triglyceride, and plasma glucose levels. MetS was defined as the presence of at least three of the following five criteria: [1] BMI?95th percentile for age and gender, [2] triglyceride level>95th percentile for age and gender, [3] HDL level<5th percentile for age and gender, [4] impaired fasting glucose?100 mg/dL, and [5] systolic or diastolic blood pressure?95th percentile for age and height. Among 450 children, 227 [50.4%] cases were male and 223 [49.6%] female. The mean age of children was 10.3 +/- 3.18 years. One hundred fifty-four cases [34.22%] had MetS and 7 cases [1.3%] met 5 criteria for MetS. Moreover, three cases [0.7%] had T2D. Significantly high frequency of the metabolic syndrome in obese children and adolescents in this city can signal a wide range of adverse health effects
ABSTRACT
Diabetes mellitus is accompanied with higher incidence of cardiovascular disorders. There is some evidence on antidiabetic potential of silymarin. In this study the effect of chronic administration of silymarin on contractile-relaxation response of thoracic aorta of diabetic rats was investigated. In this experimental study, male Wistar rats were divided into 5 groups of control, silymarin -treated control [100 mg/kg], diabetic, and silymarin -treated diabetic groups [50 and 100 mg/kg]. Ten days after streptozotocin injection, silymarin was daily administered [i.p.] for 4 weeks. At the end of study, contractile reactivity of thoracic aortic rings to KCl and phenylephrine and relaxation response to acetylcholine were determined using isolated tissue setup. Silymarin-treated diabetic group showed a significantly lower maximum contraction to KCl [at high dose] and phenylephrine at both doses [p<0.05-p<0.01] as compared to the diabetic group. Maximum relaxation response of rings to acetylcholine was significantly higher in silymarin-treated diabetic group [high dose] as compared to diabetics [p<0.05]. Meanwhile, there was also a higher relaxation response in silymarin-treated control group [high dose] in comparison to controls [p<0.05]. Chronic administration of silymarin could decrease contractile response and enhance relaxation response in aortic tissue of diabetic rat and this may be beneficial in prevention of long-term vascular complications of diabetes
ABSTRACT
Statement of Problem: Dentists and dental laboratory technicians' awareness of the dangers of cross-contaminations has made them seek the best ways to control and eradicate the main sources of infections
Purpose: The aim of this study was to evaluate the effects of spraying Deconex on three different impression materials
Materials and Method: In this in vitro experimental study, 30 circular samples of different impression materials, such as alginate, silicone and polyether impression materials were separately contaminated with Staphylococcus aureus [ATCC29213], Pseudomonas aeruginosa [ATCC27853], and Candida albicans fungus [PTCC5027]. Except for the control samples, all the other samples were disinfected with Deconex through spraying. Then, they were kept in plastic bags which were stuffed with humid rolled cotton for 5 and 10 minutes. In order to isolate bacteria, the samples were immersed in 2% trypsin for one hour and then the solution was diluted with normal saline in proportion of 1,1/2 and 1/4. The trypsin suspensions were transferred to culture plates and the number of colonies was counted after 24 and 48 hours for bacteria and after 72 hours for fungus. Data analysis was done through running Mann-Whitney Test [alpha = 0.05]
Results: There was a significant difference between the effect of Deconex on silicone and its effect on polyether for all the mentioned microorganisms after 5 minutes [p <0.05]. The highest percentage of bacterial growth prevention was recorded for silicone impression material. Deconex completely eradicated the three kinds of microorganisms after 5 and 10 minutes in the silicon group. Deconex was not capable to eliminate all three microorganisms in the polyether and the alginate groups; with the exception of Pseudomonas aeruginosa after 10 minutes
Conclusion: The results of the present study indicated that Deconex has the highest capacity when it is used with silicone; it eradicates all microorganisms in both 5 and 10 minutes
ABSTRACT
The wear resistance of composite denture teeth has been well investigated, but there have been few studies about the bonding of these teeth to acrylic denture base resins. The aim of this study was to evaluate the bond strengths of four brands of multilithic denture teeth to acrylic denture base material. In this experimental laboratory study four denture teeth groups [Glamour, Yaghout, Ivoclar and Apple] were used. Of each type of denture teeth 20 specimens were dogged into four wax prisms so that the lingual surface was faced upwards and the long axis of each of them made an angle of 90 degrees with the edge of the prism. After the placement of acryl and their curing stages, each sample was tested under shear-compressive force of 5 mm/min speed until fractured occurred. The data were analyzed by ANOVA and TUKEY test at 0.05 significance level. Apple teeth had the highest mean bond strength [1337 +/- 414/99] followed by Yaghoot [1097/36 +/- 142/86], Ivoclar [945 +/- 366/43] and Glamour [880 +/- 285/80]. Statistical analysis showed significant difference between the mean bond strength in some of denture teeth. Ivoclar specimens had the highest percentage of cohesive fracture followed by Apple, Glamour and Yaghoot. Nevertheless, statistical analysis showed no significant difference between the percentages of cohesive fracture in different groups of denture teeth. The results of this study showed that the bond strength of Apple denture teeth is more than Ivoclar and other denture teeth that were used in this study
Subject(s)
Tooth, Artificial , Acrylic Resins , DenturesABSTRACT
Vertigo is the sign of vestibular system complications that induce sense of rotation in individual toward environment or the patient himself. It also induces imbalance in gait and operational activities of patients that may lead to depression in individuals. In this study Cawthorne-cooksey exercises were used to remove signs of vestibular system complications and consequently improve balance and gait in patients suffer from vestibular complications. This study was a non-randomized prospective quisi-experimental investigation done in physiotherapy clinic of Al-zahra hospital in Isfahan province during the year 2007. As a consultation with expert statisticians, among old patients with vestibular system complications referred Al-zahra hospital, 41 patients were enrolled in to our study non-randomly. The exercises were taught to patients during three steps. Patients were asked to perform each group of exercises 10 minutes three times a day for one week. To assess the balance, gait, quality of life and depression in patients before and after treatment and also after one month follow-up, we used Berg Balance Scale, Dynamic Gait Index, Dizziness Handicap Inventory, and Beck questionnaire respectively. To analyze data paired t-test and Wilcoxon test were used. There was statistical significant difference in balance before and after treatment [P < 0.001], before treatment and after follow-up [P < 0.001], and also after treatment and after follow-up [P < 0.001]. There was statistical significant difference in gait before and after treatment [P < 0.001], before treatment and after follow-up [P < 0.001], and also after treatment and after follow-up [P < 0.001]. There was statistical significant difference in quality of life before and after treatment [P < 0.001], before treatment and after follow-up [P < 0.001], and also after treatment and after follow-up [P < 0.001]. There was statistical significant difference in depression before and after treatment [P < 0.001], before treatment and after follow-up [P < 0.001], and also after treatment and after follow-up [P < 0.001]. We conclude that using Cawthorne-cooksey exercises lead to improve balance, gait, quality of life and depression in adult patients for at least one month. To achieve desired treatment goals, patients should continue their daily activities even after one month for a long period of time
ABSTRACT
When implants are used to support an over denture, the optimal stress distribution is desirable to minimize the forces on the implants. The purpose of this study was to compare stress patterns generated around implant supported over denture with two different bar attachment systems ITI [Dolder] and OT with finite element method. In this descriptive study, the stress distribution around dental implants in an edentulous mandible with two different bar attachment systems [OT without spacer and ITI [Dolder] with spacerl was calculated by means of three-dimensional, finite-element model of an entire lower jaw. This model was provided with two endosseous implants in the canine region. The implants were connected to a 2 mm bar height and a vertical force was applied to the first left molar and gradually increased from 0 to 50N. Then, resultant stress distribution was evaluated. In OT and ITI [Dolder] bar attachments, the maximum von Mises stress values were observed in the cortical bone adjacent to the implant neck and this value was higher for OT bar [6.114Mpa] than ITI [Dolder] bar attachment [3.896 Mpa]. This 3-D FE study suggested that the use of ITI [Dolder] bar attachment with spacer is more advantageous than OT bar attachment for implant-supported overdenture with regard to optimizing stress distribution
Subject(s)
Finite Element Analysis , Dental Stress AnalysisABSTRACT
Multiple sclerosis [MS] is the most common progressive neurological disorder in the young adults. One of the areas that are affected in MS is the cerebellum. Ddisorders in this structure leadss to ataxia, imbalance, and so on, that can decrease patient's quality of life. Exercise therapy is an effective method to decrease functional disorders in MS patients. This study shows the effectiveness of Frenkel's exercises in improvement of conditions in MS patients. This is was a double-blinded, perospective and quinsy-experimental study that was done in Isfahan, during 1385-786. In this experiment, 22 MS patients with cerebellar disorder. [mean age 33.36 years, mean height 64.14 cm, and mean weight 61.95 kg], was learned Frenkel's exercises alternatively in 10 sessions. Evaluation was done before and after the treatment. In order to study ataxia we used ataxia rating scale, Berg balance scale for to assess balance, Barthel index, for to study activity of daily living [ADL], and questionnaire of beck for to judge depression. We used SPSS soft ware. For statistic studying and analyzing of obtained results and for comparing the conditions of patients in different stages, paired-t-test was used. The findings of this current study showed a meaningful difference of ataxia [P<0.05] Balance [p<0.05] and depression [p<0.05] evaluation between before and after the treatment. The obtained result showed that doing Frenkel's exercises, Continuously leads to improve the ataxia, blance, ADL and depression in patients with MS.
ABSTRACT
Parkinson s disease is a progressive and degenerative disease of the basal ganglia of the brain. Four major signs of this disease are: bradykinesia, tremor, rigidity and postural instability. Postural instability is the main cause of falling in these patients. Despite the importance of the role of the exercise therapy in reducing the secondary signs of akinesia in these patients, there is not enough evidence to express the effects of these exercises. The current study carried out to reveal that. In a Single -blinded, prospective and Quasi -experimental study 23 patients with Parkinson were chosen [age=67/43 +/- 7/75, height=169/74 +/- 8/44, weight=65/61 +/- 7/85] and were arranged to do exercise therapy with Swissball with the full supervision of the physical therapist for 12 sessions [one hour in each every session three sessions per week]. An evaluation was done before and after treatment and a follow up month later. To evaluate the balance of these patients Berg Balance Scale was used and beck depression questionnaire to assess the depression of these patients. The results were analysed by Spss software and paired t-test. A meaningful difference in balance evaluation was achieved between before the treatment and after the treatment [P=0.00]. A meaningful difference in balance evaluation was achieved between before the treatment and after one -month follow- up [P=0.00]. There was No meaningful difference between after the treatment and after one-month follow-up [P=0.141]. There was a meaningful difference in depression evaluation between before the treatment and after the treatment [P=0.00]. There was a meaningful difference in depression evaluation between before the treatment and after one -month follow- up [P=0.00]. There was No meaningful difference in depression evaluation between after the treatment and after one-month follow-up. [P=0.56]. With regard to the results of this study it might be concluded that Swissball exercises improve the balance and depression of patients with Parkinson in short term [one month]. It must be notified that of Exercises does not continue depression and balance problems due to progressive nature of the disease
ABSTRACT
Impairment in the function of the brain caused by deficiency in the brain circulation is called stroke. Stroke is the most important factor of disability in adults. One of the most prevalent consequences of stroke is disability of walking or so-called [gait disorder] so that more than 50 percent of the patients who are in the acute phase of the disease are not capable of walking, and need to a rehabilitation period to reach for walking. In order to compare the effect of exercise therapy on the function of walking and balance and Improvement of depression in left and right hemiplegics patients, a Non-randomized clinical study was done. This study consisted of 13 right- hemiplegics patients with an average age of [60.46 +/- 1.47] and 13 left hemiplegics patients with an average age of [61.92 +/- 2.01] who were matched in age, height and weight. To measure the function of walking the Gait Dynamic Index, function of balance the Berg Balance Scale and Depression Beck Depression Questionnaire were used. The data were analyzed by SPSS software. To compare the effect of exercise therapy on the improvement of walking and balance before and after the treatment in each group t-paired -test and for more comparison of the two groups an independent T-test was used. With analyzing the received data the following results were derived: From the viewpoint of walking, a significant difference in the right hemiplegics group [p<0.001] and the left hemiplegics one [P=0.0] before and after the treatment is derived. From the viewpoint of balance, a significant difference in the right hemiplegics group [p<0.001] and the left hemiplegics group [P=0.0] before and after the treatment was noticed. About the improvement of depression, a significant difference in the right hemiplegics group [p<0.001] and the left one [p<0.00l] before and after the treatment was noticed. There was no significant difference between two groups before [p=0.85] and after [0.36] the treatment from the point of view of walking. There was no significant difference between two groups before [p=0.056] and after [p=0.067] the treatment in balance. There was no significant difference between two groups before [p=0.067] and after [p=0.054] treatment from the viewpoint of depression. This study showed that performing the exercise therapy protocol improves the function of walking, balance and depression in herniplegic patients; never the less, no differences were observed between the two right and left hemiplegics groups