[Effects of rewash on the accuracy of stone dies produced by putty-wash technique]

An accurate impression of teeth and supporting structure is necessary to restore a lost tooth structure or to replace a tooth with crown and bridge. Although there are various methods for making impression, putty-wash technique is currently preferred since it is simple and does not require a special tray. Silicone elastomeric impression materials have suitable consistency for putty-wash technique and are thus widely used. Considering the existing controversies over the effects of impression technique on the accuracy of restoration, we evaluated the effects of rewash on the accuracy of stone dies produced by a putty-wash technique. In this laboratory study, a model with two metallic dies was used. One die had a horizontal notch as an undercut. Ten impressions were made with spacer and ten impressions with rewash technique. A profile meter with accuracy of one micron was used to measure the dimensions of the produced stone models. The original and produced models were compared by t-test. The mean height of dies without undercut decreased significantly in both groups [11.69 with spacer, P < 0.001 and 11.44 with rewash P < 0.001]. The mean diameter of dies without undercut decreased in both groups [10.39 with spacer and 10.27 with rewash] but the difference was only significant using rewash technique [P = 0.018]. The mean distance between two dies increased in both techniques [30.25 with spacer and 30.43 with rewash]. Again, the difference was only significant using rewash technique [P < 0.001]. The mean diameter of dies below the undercut increased with spacer technique [10.33; P > 0.05] and decreased with rewash technique [10.21; P < 0.001]. The mean height of dies above the undercut decreased significantly in both groups [9.99 with spacer P < 0.001 and 10.21 with rewash P < 0.001]. The impression technique with spacer was more accurate in all dimensions as compared to rewash technique

[Barriers to blood glucose level management in the health care system: view points of patients, families and medical personnel]

Health care system barriers are major barriers to management and control of blood glucose level control. Documenting the viewpoints of patients, their families and the medical team, on these barriers is an important step towards correct planning and effective control of blood glucose. This study aimed to document and compare viewpoints of patients, their families and medical team about health care system barriers to control of glucose levels in diabetes centers of Isfahan city. This was a descriptive- comparative, cross-sectional, one stage, study of three groups, in which a total of 938 subjects, including 420 type2 diabetic patients, 420 members of their families and 98 medical staff participated. Data were collected using a researcher-designed questionnaire that was completed by subjects. Data were analyzed using descriptive and inferential statistical methods and SPSS software. Results showed significant differences between viewpoints of the 3 groups, i.e. patients, their families and the medical team regarding barriers of the health care system to blood glucose control [Pvalue< 0.001]. The medical team gave the highest importance to these barriers, while patients gave the lowest. Regarding the significant differences between the viewpoints of these three groups, it can be concluded these differences account for lack of success in controlling patient glucose levels, because medical teams focus on barriers that are not so important to patients and their families, while barriers which are important to patients and their families are less considered by members of the medical team

[Accuracy and dimensional stability of two polysiloxane putty- wash impression techniques]

The accuracy and dimensional stability of dental impression materials and technique is an important factor in the accuracy and fitness of the final restoration. Condensation- reaction polysilicone impression material has adequate accuracy and is the most commonly used material in fixed prosthodontic restorations with putty- wash technique. There are different considerations and controversies in the literature about the effect of impression technique on the accuracy of restoration. The aim of this study was to compare the accuracy and dimensional stability of two polysiloxane putty- wash impression techniques with and without spacer. A laboratory model with two metallic dies was used. In one of the dies a horizontal notch was applied as an undercut. Ten impressions were made without spacer and another ten with spacer. Twenty stone models were made from both techniques. Dimensions of the stone models were measured and comparison was made with the laboratory model dimensions. The results were analyzed using T- test. The results showed that the height of the dies without undercut was decreased in both groups, being significant in non- spacer technique [p<0.001]. The distance between the two dies increased in both techniques. The difference was significant in technique without spacer [p<0.002]. The height of the dies above the undercut increased and in both techniques they proved to be statistically significant [without spacer p<0.003 and with spacer p<0.001]. The polysiloxane putty- wash impression technique with spacer is more accurate for fabricating the stone die

[ effect of post material on stress distribution in mandibular second premolar tooth by finite element analysis]

The restoration material commonly used as core material for pulpless posterior teeth is mostly amalgam due to its high strength and low cost and it can be used with or without pin. The aim of this study was to evaluate the influence of post material on stress distribution in mandibular second premolar tooth by finite element analysis. The stress distribution was analyzed in amalgam core supported with and without pin. Three dimensional plane strain models of the human mandibular second premolar were first made with pin amalgam and then with post amalgam. After applying the loading force at 45 degree angel, the stress distribution was analyzed in models. Maximum stress in pin amalgam was more than that in post amalgam. The area of maximum stress in pin amalgam was at pin and core interface but in post amalgam it was at the margin of core in the side of applied force. The least stress was at the margin of core opposite to the side of force in both models and was more in pin amalgam than post amalgam. As the stress was more in pin amalgam than post amalgam so it can be said that the fracture strength of post amalgam is more than pin amalgam. Since crown increases fracture resistance of post and core, further studies for analysing stress distribution of amalgam core with crown is recommended

[Prevalence of hypertension in Iranian urban and rural populations aged over 20 years in 2004]

Several studies have shown differences in HTN prevalence between urban and rural populations. The aim of this study was to compare the prevalence of HTN and the status of HTN awareness, treatment and control between Iranian urban and rural populations aged over 20 years. As a part of a nation-wide survey in 2004 on risk factors of non-communicable diseases, a cross-sectional study was performed on 75.132 adults aged over 20 years. In all participants, blood pressure was measured for twice in a standard method, followed by a collection of data on patients' awareness, treatment and control of HTN. The data were compared between urban and rural populations. The crude prevalences of HTN were 30.5% [CI 95%: 30.496- 30.50], 29.2% [CI 95%: 29.19-29.21], and age-adjusted prevalences were 26.09% [CI 95%: 26.086-26.094] and 26.03% [CI 95%: 26.015-26.025] for urban and rural populations, respectively. Rural residents were significantly less aware of HTN, its treatment and control than urban people. Considering the similarity of age-adjusted HTN prevalence between Iranian rural and urban communities, there is the same burden on our health system. With respect to the lower degree of HTN awareness and control in rural residents, and the integral role of rural health system in diminishing the mentioned difference, further developments are recommended for system

Hypertension and pre-hypertension: prevalence, awareness and management among Iranian adults older than 20 years

Hypertension [HTN] is an important worldwide challenge. The 7th report of the Joint National Committee [JNC7] provided the last classification of blood pressure levels and introduced the new category of prehypertension. The aim of this study was to estimate the national prevalence of HTN and prehypertension according to the JNC7 guideline and to determine the status of HTN awareness, treatment and control in Iranian adults aged older than 20 years. This cross-sectional study was a part of a nationwide survey on the risk factors for non-communicable diseases, which was conducted in 2004. In 75112 over 20 year old adults, two blood pressure measurements were obtained by a standard method and blood pressure levels were classified according to the JNC7 criteria. Data on patients' awareness, management and treatment of HTN were also collected. The age-adjusted prevalence of HTN and prehypertension was 25.3% and 49.7% in men, and 26% and 38% in women, respectively. Only 35% of hypertensive subjects were aware of their disease, and effective control was observed in 21.4% of them. Considering the high prevalence of HTN and prehypertension and the low awareness and effective control of HTN, our country is facing a serious health problem

[Comparative study of microleakage of full crown restorations luted with Ariadent and Harward Zinc Phosphate cements]

Film thickness, strength, solubility and microleakage of dental cements are essential factors in cement selection by dentist. Since failure of metal ceramic restorations is mostly due to their marginal leakage and previous studies have shown that microleakage of Resin, Glassionomer and Zinc Phosphate cements are different, this study was done to compare the rate of microleakage between Ariadent and Harward Zinc Phosphate cements. In the case of observing no difference in microleakage of 2 cements Ariadent Zinc Phosphate cement which is more available than Harward Zinc Phosphate cement can be recommended. 40 sound permanent premolar teeth extracted for orthodontic purposes were used. Standard metal-ceramic preparation had been performed for all the teeth. In each tooth shoulder and chamfer finishing lines had been produced in labial and lingual surfaces respectively. After preparation of metal copings the prepared teeth were randomly divided into 2 experimental groups. In 1 group copings were cemented by Ariadent Zinc Phosphate cement and in the other group Harward Zinc Phosphate cement was used for luting. Both groups were sectioned buccolingually. The amount of dye microleakage was measured by stereomicroscope and non-parametric Willcoxon test was used for data analysis. Results showed that the mean of dye microleakage in Ariadent Zinc Phosphate cement in labial [1.4 +/- 1.17] and lingual surfaces [1.81 +/- 1.4] were less than those in Harward Zinc Phosphate cement [1.71 +/- 0.84 and 1.97 +/- 1.05 respectively]. There was no significant difference in microleakage between the 2 experimental groups

[Comparative study of microleakage of full crown resterations luted with Ariadent and Harward zinc phosphate cements]

Film thickness, strength, solubility and microleakage of dental cements are essential factors in cement selection by dentist. Since failure of metal ceramic restorations is mostly due to their marginal leakage and previous studies have shown that microleakage of Resin, Glassionomer and Zincphosphate cements are different, this study was done to compare the rate of microleakage between Ariadent and Harward zinc phosphate cements. In the case of observing no difference in microleakage of two cements Ariadent zinc phosphate cement which is more available than Harward zinc phosphate cement can be recommended. Forty sound permanent premolar teeth extracted for orthodontic purposes were used. Standard metal-ceramic preparation had been performed for all the teeth. In each tooth shoulder and chamfer finishing lines had been produced in labial and lingual surfaces respectively. After preparation of metal copings the prepared teeth were randomly divided into two experimental groups. In one group copings were cemented by Ariadent zinc phosphate cement and in the other group Harward zinc phosphate cement was used for luting. Both groups were sectioned buccolingually. The amount of dye microleakage was measured by stereomicroscope and non parametric willcoxon test was used for data analysis. Results showed that the mean of dye microleakage in Ariadent zinc phosphate cement in labial [1.4 +/- 1.17] and lingual surfaces [1.81 +/- 1.4] were less than those in Harward zinc phosphate cement [1.71 +/- 0.84 and 1.97 +/- 1.05 respectively]. There was no significant difference in microleakage between the two experimental groups