Background and Objective: T3 resin uptake test indicates the availability of thyroxin binding globulin (TBG), which is the carrier of a large amount of T3 and T4 in blood. We aimed to study the relationship between serum T3 Resin Uptake and serum lipids profile.Material and Methods: The participants aged 14.80±38.29 were both males (59; 29.5%) and females (141; 70.5 %). T3 Resin Uptake was measured by Immunoassay method and serum lipid profile components (cholesterol, triglycerides, HDL-C, LDL-C, and VLDL) were measured by the kit. Results: Significant negative correlation was observed between serum T3 Resin Uptake and cholesterol, triglycerides and LDL-C (P£0.05), but that was not the case for HDL-C and VLDL.Conclusion: Serum T3 Resin Uptake can be evaluated to assess the risk factors related to cardiovascular disorders.

Changes of up to 80°C has been reported for oral cavity temperature. This could well effecti on the nature of restorations for example failure of bonding of adhesive restorations. It is advocated that using opaque layer in porcelane to restorations could reduce this problem. This experimental study was designed to evaluate the effect mentioned using finitelement analysis method.Results showed that cooling has a more destructive effect than warming process restorations with the presence of opaque having a finitelement analysis effect on restorations.

Introduction: According to appropriate characteristics of glass ionomer cementum and constant increase of its usage in restorative field, so comparison of conventional and resin- modified glass ionomers seems to be useful. This study was designed to determine the shear bond strength of conventional and resin- modified glass Ionomers on enamel, dentin and cementum.Methods: This was an experimental study. Totally 60 molar intact teeth were divided into six groups. In groups A and D the surface of enamel was prepared 1mm, in groups B and E, the preparation was continued until the surface of dentin was exposed and in groups F and C the surface of cementum was only refreshed.In groups A, B, and C conventional glass ionomer and in groups F, E, and D resin-modified glass ionomer was used. For each specimen a plastic cylinder with 2mm diameter and 3mm height was bonded on treated surface and the teeth were filled by the relevant glass ionomer. In groups F, E, and D glass ionomer was light cured for 40 seconds. specimens were loaded to failure in a universal testing machine Then statistical analysis was performed using one- way ANOVA and LSD test (P=0.05).Results: The mean shear bond strength of groups A, B, C, D, E and F were 17.25, 14.77, 15.37, 27.30, 57.80, 23.50 Mpa, respectively. The difference between shear bond strength of groups F, E, and D with groups A, B, and C was statistically significant (P=0.001).Conclusion: The shear bond strength of the resin-modified glass Ionomers was significantly higher than that of conventional glass ionomer in all three surfaces.

Objective: Fabrication of indirect onlays and inlays and their cementation with resin cements have become increasingly popular. Resin cements used in indirect restoration cementations provide weaker bonds when compared with the bond strength supplied ژin a dentin bonding used for direct composites. This results in debonding of indirect restorations and consequent problems. Resin coat technique has been advocated as a solution. It is claim to increase the bond strength of resin cements to dentin using this technique. The purpose of this study was to evaluate the effects of storage time and resin coat technique on the panavia F cement tensile bond strength to dentin. Methods and Materials: Sixty extracted human third molars were divided into six groups of ten. The occlusal surfaces were trimmed to the exposure of the very first dentin layer. The specimens were placed under the following experimental conditions: Group 1: control group 1, no surface treatment on dentin with storage under distilled water for 24 hours. Group 2: control group 2, no surface treatment on dentin with storage under distilled water for 7 days Group 3: Resin coated dentin with clearfil liner bond 2V and storage under distilled water for 24 hours. Group 4: Resin coate dentin with clearfil bond 2V and storage under distilled water for 7 days. Group 5: Resin coated dentin with clearfil bond 2V and flowable composite and storage under distilled water for 24 hours Group 6: Resin coated dentin with clearfil bond 2V and flowoble composite and storage under distilled water for 7 days . Nickel chrome rod was bonded to the above surfaces using panavia F. Tensile bond strengths were evaluated with instron machine Paired t-test was used to detect differences among experimental groups and ANOVA test for comparison between the 6 groups.Results: The mean tensile bond strengths ± standard deviations were as following: Group1: 15.94±5.27, Group 2: 12.43±4.75, Group 3: 15.36±5.41, Group 4: 10.61±3.53, Group 5: 18.45±6.18 and Group 6: 13.34±4.4 PMa. Statistical analysis showed no significant differences between groups 1 and 2. However, there was a significant difference between the highest strength was found in group 5, and the lowest one in group 4. (P<0.05). a7- day storage, to 1 day storage reduced paravia F bond strength to resin coated dentin ( P< 0.05). In all groups, inter facial failure was an adhesive failure between cement and dentin or resin coated dentin.Conclusion: Bonding strength was not improved by using resin coat technique. Usage of flow able composite in combination with clearfil liner bond 2V had not effect on bonding strength. Decrease in bonding strength after 7 days storage of resin-coated dentin was seen.

Statement of Problem: The use of dentine bondings on enamel and dentin in total etch protocols has recently become popular. Unfilled resin is hydrophobic and dentin bonding is hydrophilic in nature. This chemical difference could be effective in enamel bonding process.Purpose: The aim of this study was to compare the shear bond strength of unfilled resin to dry enamel and dentin bonding to dry and moist enamel.Materials and Methods: In this experimental study, a total of 30 incisor teeth were used. The specimens were randomly assigned to three groups of 10. 37% phosphoric acid etchant was applied to the enamel surfaces in each group for 15 seconds, rinsed with water for 20 seconds and dried for 20 seconds with compressed air in groups one and two. After conditioning, group 1 received unfilled resin (Margin Bond, Colten) and group 2 received dentin bonding (Single Bond, 3M) and in group 3 after conditioning and rinsing with water, a layer of dentin bonding (Single Bond) was applied on wet enamel. The enamel and dentin bonding were light cured for 20 seconds. A ring mold 3.5 mm in diameter and 2 mm height was placed over the specimens to receive the composite filling material (Z100, 3M). The composite was cured for 40 seconds. The specimens were thermocycled and shear bond strengths were determined using an Instron Universal Testing Machine. The findings were analyzed by ANOVA One-Way and Tukey HSD tests.Results: Shear bond strength of dentin bonding to dry enamel was significantly less than unfilled resin to dry enamel (P<0.05). There was no significant difference between the bond strength of dentin bonding to moist and dry enamel. In addition bond strength of dentin bonding to wet enamel was not significantly different from unfilled resin to dry enamel.Conclusion: Based on the findings of this study, it is suggested that enamel surface should remain slightly moist after etching before bonding with single bond but when using unfilled resin, the enamel surface should be kept dry.

Statement of Problem: There are controversial reports regarding physical and mechanical properties of resin composites and glass ionomer cements. Some revealed higher strength and hardness for resin composites while others showed a comparable value for glass ionomer cements. Evaluation of mechanical properties of different types of resin composites in comparison with resin modified glass ionomers is not widely studied.Objectives: To measure and compare the flexural strength and Vickers hardness of three resin composites and two resins modified glass ionomer cements before and after ageing.Materials and Methods: Three resin composites, i.e. Filtek Supreme XTE (3M ESPE), Ice (SDI), Gradia (GC), and two resins modified glass ionomers, i.e. Fuji II LC (GC) and Riva Light Cure (SDI), were selected. Ten barshaped specimens were prepared for each material and cured using LED curing light. After 24 hours storage in distilled water at 37oC, the specimens were randomly divided into two equal groups (n=5). The first group was tested as a baseline and the second group was restored at 37oC for another 29 days. Flexural strength was performed by four-point bending test using universal testing machine at crosshead speed of 0.5mm/min, and the maximum load at failure was recorded. The specimen’s halves were used for evaluating Vickers hardness, using a Digital Hardness Tester (300 g/15 sec) and the Vickers hardness number (VHN) was recorded. Data were analyzed using one-way analysis of variance (ANOVA), Tukey’s and student’s t-test.Results: After 24 hours of immersion, the highest hardness number was found for Filtek Supreme and Ice and the highest flexural strength was obtained for Gradia. After 30 days of storage, hardness of Fuji II LC and Gradia showed a significant decrease; flexural strength of Ice and Fuji II LC revealed a significant increase while Gradia and Filtek Supreme showed a significant decrease.Conclusions: Resin modified glass ionomers showed a comparable result for hardness and flexural strength with some of the tested resin composites and lower values than some others.

Background and purpose: Deep fissures of occlusal surface in recently erupted first permanent molars are prone to accumulation of bacterial plaque. Sealing these fissures by appropriate flowing materials, as pit and fissure sealants, is a conservative way to prevent caries. The purpose of this study was to compare retention of flowable composite resin by resin modified glass ionomer sealant in six months period.Materials and methods: The occlusal surfaces of the first permanent mandibular molars of 50 children aged 6 to 12 attending pediatric department in dental school affiliated with Qazvin University of Medical Sciences were assessed via Williams probe, intra-oral mirror, and diagnodent. After confirming absence of caries, flowable composite resin were placed on the left first permanent mandibular molars, and resin modified glass ionomer (RMGI) were placed on the opposite side. After 6 months, 46 patients referred for follow up, in whom the retention of sealants was assessed using sharp explorer and intra-oral mirror, and caries were assessed via diagnodent. Data was analyzed in SPSS20 applying Chi- square test.Results: The retention of flowable composite (91.3%) was significantly more than that of the resin modified glass ionomer (56.5%) (P<0.05). There were no cases with total loss of material in flowable composite. No caries were observed using the diagnodent.Conclusion: The flowable composite resin could be used as a fissure sealant agent, due to its greater retention compared to resin modified glass ionomer.