Desmopressin/indomethacin combination efficacy and safety in renal colic pain management: A randomized placebo controlled trial.

INTRODUCTION: Renal colic is a prevalent cause of abdominal pain in the emergency department. Although non-steroidal anti-inflammatory drugs and opioids are used for the treatment of renal colic, some adverse effects have been reported. Therefore, desmopressin -a synthetic analogue of vasopressin- has been proposed as another treatment choice. In the present study, indomethacin in combination with nasal desmopressin was compared with indomethacin alone in the management of renal colic. METHODS: Included in the study were 124 patients with initial diagnosis of renal colic and randomized to receive indomethacin suppository (100 mg) with either desmopressin intranasal spray (4 puffs, total dose of 40 micrograms) and or placebo intranasal spray. RESULTS: All the included patients were finally diagnosed with renal colic. There was no difference between the two groups in pain at the baseline (p = 0.4) and both treatments reduced pain successfully (p < 0.001). There was no significant difference between the two groups in pain reduction (p = 0.35). CONCLUSIONS: While there was significant pain reduction in both patients groups, pain reduction of NSAIDs (e.g. indomethacin) in renal colic, does not significantly improve when given in combination with desmopressin.

Head CT scan in Iranian minor head injury patients: evaluating current decision rules.

The objective of this study is to select one of the seven available clinical decision rules for minor head injury, for managing Iranian patients. This was a prospective cohort study evaluating medium- or high-risk minor head injury patients presenting to the Emergency Department. Patients with minor head trauma who were eligible for brain imaging based on seven available clinical decision rules (National Institute for Health and Clinical Excellence (NICE), National Emergency X-Radiography Utilization Study (NEXUS)-II, Neurotraumatology Committee of the World Federation of Neurosurgical Societies (NCWFNS), New Orleans, American College of Emergency Physicians (ACEP) Guideline, Scandinavian, and Canadian computed tomography (CT) head rule) were selected. Subjects were underwent a non-contrast axial spiral head CT scan. The outcome was defined as abnormal and normal head CT scan. Univariate analysis and stepwise linear regression were applied to show the best combination of risk factors for detecting CT scan abnormalities. Five hundred patients with minor head trauma were underwent brain CT scan. The following criteria were derived by stepwise linear regression: Glasgow Coma Scale (GCS) less than 15, confusion, signs of basal skull fracture, drug history of warfarin, vomiting more than once, loss of consciousness, focal neurologic deficit, and age over 65 years. This model has 86.15 % (75.33-93.45 %) sensitivity and 46.44 % (46.67-51.25 %) specificity in detecting minor head injury patients with CT scan abnormalities (95 % confidence interval). Of seven decision rules, only the Canadian CT Head Rule possesses seven of the eight high-risk factors associated with abnormal head CT results which were identified by this study. This study underlines the Canadian CT Head Rule's utility in Iranian minor head injury patients. Our study encourages researchers to evaluate available guidelines in different communities.

Evaluation of the Fracture Resistance of Conservative and Ultraconservative Access Cavity Designs with Different Treatment Modalities: An In Vitro Study.

Introduction: The aim of this study was to evaluate the fracture resistance of endodontically treated mandibular molars using traditional and conservative access cavity preparation. Materials and Methods: In this in vitro study, 100 extracted healthy human mandibular molars were selected and divided into 10 groups (n = 10). Healthy teeth in one group were considered the control group. In three groups, traditional access cavity preparation was done (groups A) without two marginal ridges (A1), with one marginal ridge (A2), and with two marginal ridges (A3). In three groups (group B), two separate access cavities with a dentinoenamel roof without two marginal ridges (B1), with one marginal ridge (B2), and with two marginal ridges (B3) were prepared. In three other groups (groups C), two separate access cavities were prepared only with a dentinal roof without two marginal ridges (C1), with one marginal ridge (C2), and with two marginal ridges (C3), on which root canal treatment was performed afterward. Then, these teeth were subjected to force until fracture. The fracture force and fracture mode of each tooth were recorded and compared between groups by ANOVA, Tukey's post hoc, and chi-square tests using SPSS ver. 23 (IBM, Somers, NJ, USA). Results: The control teeth had the highest mean fracture force (2804.5 ± 338.5 N), followed by a conservative access cavity with a dentinoenamel roof and two marginal ridges (2360.4 ± 181.72 N) and a conservative access cavity with a dentinoenamel roof and one marginal ridge (1812.8 ± 263.9 N), respectively. The lowest mean fracture force was found for the conventional access cavity group without two marginal ridges (399.4 ± 95.2 N). Conclusion: In the condition of this study, with two separate access cavities in mandibular molars and maintenance of the marginal ridges, it is possible to provide teeth with higher fracture resistance against occlusal forces.

The effect of silver diamine fluoride on the bond strength of glass ionomer to the enamel of primary teeth.

Background: Dental caries is a disease which is caused by the acidic by-products of the metabolic processes of dental plaque. Silver components are one of the clinical solutions to prevent caries. This study aimed to investigate the effect of silver diamine fluoride (SDF) application on the shear bond strength of glass ionomer to primary teeth enamel. Materials and Methods: In this in vitro study, a total of 48 anterior sound primary teeth were randomly divided into four groups (n = 12). The control group (G1) consisted of healthy primary teeth, and the three experimental groups (G2-G4) were composed of demineralized primary teeth. The second group did not undergo SDF treatment, the third group underwent SDF treatment, and the fourth group underwent SDF treatment plus polishing. Glass ionomer cylinders were bonded to all specimens and subsequently tested by a universal testing machine to measure the glass ionomer shear bond strength. The type of fracture was examined by a stereomicroscope. Data analysis was carried out using the SPSS 22 statistical software. Data were analyzed by one-way analysis of variance and posthoc Tukey tests (α =0.05). Results: The mean shear bond strength of the glass ionomer was significantly higher in the control group than in the other three groups (P < 0.05). The mean shear bond strength of glass ionomer was significantly higher in the SDF-treated group than in the non-SDF treated and SDF-treated and polished groups (P < 0.05). Conclusion: Although the glass ionomer bond strength to sound enamel was higher than other groups by a significant margin, the application of SDF increases the shear bond strength of the glass ionomer to remineralized white spot enamel in primary teeth.

Attitude toward end-of-life care in emergency medicine residents- can a short workshop make a difference?

BACKGROUND: There is a growing demand for palliative care (PC) in Emergency departments (ED) as the number of patients who need end-of-life (EOL) care is increasing. Despite significant variability amongst residency programs, there is a lack of structured core curriculum for PC/EOL care in most emergency medicine (EM) training programs, which often do not meet the needs of EM physicians. In this study, we evaluate the effect of a short EOL care workshop on changing the attitude of Iranian EM residents towards EOL care in ED. METHOD: In this prospective before/after educational study at Tehran University of medical science, we enrolled 40 EM residents using a random sampling method. We obtained demographic and practice background information, and participants underwent a half-day PC training workshop designed by an expert panel. We administered a translated and validated Standard PEAS (physician End of Life Care Attitude Scale) questionnaire before and four weeks after an educational intervention. Baseline and differences in attitude were reported and compared by paired t-test, repeated measure ANOVA, and ANOVA. RESULTS: None of the participants had prior experience of formal PC training. All of the 40 participants completed the follow-up questionnaire. Baseline attitude was not different among demographic groups. The mean (SD) PEAS score before and four weeks after the workshop was 86.9 (5.8) versus 89(6.9), respectively (P = 0.023). Residents with no previous close exposure to a terminal illness in their family members had significantly more attitude change than those with such an experience (P = 0.045). CONCLUSION: A brief educational intervention improved EM residents' attitudes toward EOL care. The optimal design and characteristics of this educational intervention yet remain to be defined by further studies.

Cinnamic acid derivatives as potential matrix metalloproteinase-9 inhibitors: molecular docking and dynamics simulations.

Matrix metalloproteinase-9 (MMP-9) is a zinc and calcium-dependent proteolytic enzyme involved in extracellular matrix degradation. Overexpression of MMP-9 has been confirmed in several disorders, including cancers, Alzheimer's disease, autoimmune diseases, cardiovascular diseases, and dental caries. Therefore, MMP-9 inhibition is recommended as a therapeutic strategy for combating various diseases. Cinnamic acid derivatives have shown therapeutic effects in different cancers, Alzheimer's disease, cardiovascular diseases, and dental caries. A computational drug discovery approach was performed to evaluate the binding affinity of selected cinnamic acid derivatives to the MMP-9 active site. The stability of docked poses for top-ranked compounds was also examined. Twelve herbal cinnamic acid derivatives were tested for possible MMP-9 inhibition using the AutoDock 4.0 tool. The stability of the docked poses for the most potent MMP-9 inhibitors was assessed by molecular dynamics (MD) in 10 nanosecond simulations. Interactions between the best MMP-9 inhibitors in this study and residues incorporated in the MMP-9 active site were studied before and after MD simulations. Cynarin, chlorogenic acid, and rosmarinic acid revealed a considerable binding affinity to the MMP-9 catalytic domain (ΔGbinding < -10 kcal/ mol). The inhibition constant value for cynarin and chlorogenic acid were calculated at the picomolar scale and assigned as the most potent MMP-9 inhibitor from the cinnamic acid derivatives. The root-mean-square deviations for cynarin and chlorogenic acid were below 2 Å in the 10 ns simulation. Cynarin, chlorogenic acid, and rosmarinic acid might be considered drug candidates for MMP-9 inhibition.

Effects of Rinsing Water Temperature and Preheated Composites on Microleakage of Composite Restorations with Two Bonding Agents.

Objectives: The aim of this study was to evaluate the effects of rinsing water temperature and preheated composites on microleakage of class V restorations with two different bonding agents. Materials and Methods: Eighty class V cavities were prepared in the buccal and lingual surfaces of 40 molars. Single Bond and Prime and Bond NT bonding agents were used. The teeth were divided into four groups of 10. G1: After acid etching, cavities were rinsed with 23˚C water and filled with 23˚C composite resin. G2: Rinsing water and composite resin had 55˚C temperature. G3: Rinsing water had 55˚C and composite resin had 23˚C temperature. G4: Rinsing water had 23˚C and composite resin had 55˚C temperature. The specimens were immersed in 0.5% basic fuchsine dye. Microleakage scores were analysed with the Kruskal-Wallis, Mann-Whitney U, and Wilcoxon tests. Results: There were significant differences in microleakage of specimens prepared with Single Bond and Prime and Bond NT only in group 1 (P<0.05). There were no significant differences between the microleakage of groups rinsed with different water temperatures (P>0.05). There were significant differences between the unheated and preheated composite groups (P<0.05). Conclusion: Preheating of composite is a valuable method to increase its adaptability and decrease microleakage of composite restorations.

Evaluation of the Effect of Anti-COVID-19 Mouthwashes on Shear Bond Strength of Composite Resin Restorations to Dentin and Enamel: An "In Vitro Study".

Objectives: Given the high prevalence of the coronavirus and the high risk of virus transfer to dentists, the use of mouthwashes, which can potentially eliminate this virus, is suggested before dental procedures. Since these mouthwashes may affect the bond strength of composite resin restorations to teeth, this study was conducted to investigate the effect of recommended mouthwashes on the shear bond strength of composite resin restorations to dentin and enamel in selective etch and rinse and two-step self-etch bonding systems. Methods: Five groups of posterior teeth (n = 15) were selected for five groups of cetylpyridinium chloride 0.07%, povidone-iodine 1%, hydrogen peroxide 1%, and chlorhexidine 0.2% as mouthwash and distilled water as the control group. The buccal enamel and lingual dentin of each tooth were rinsed after immersion in a mouthwash. After 20 seconds of enamel acid-etching and 15 seconds of dentin priming, they were impregnated with an adhesive, and composite cylinders were placed on the dentin and enamel surfaces of the tooth. The shear bond strength test was performed after 24 hours, and results were analyzed by ANOVA and paired t-test (α = 0.05). Results: The mean shear bond strength of enamel to composite was significantly (p < 0.05) higher than that of dentin to composite in each study group, but no significant difference was found between the mean shear bond strength of composite to enamel (p = 0.199) and to dentin (p = 0.335) after the use of mouthwashes and that of the control group. Conclusion: The use of mouthwashes used in this study did not have negative effects on the shear bond strength of composite to enamel and dentin.

Effect of different surface treatment with panaviaV5 on shear bond strength of metal brackets to silver amalgam.

BACKGROUND: This study was conducted to compare the shear bond strength (SBS) of orthodontic brackets to amalgam surfaces by two surface treatment methods, two different adhesives, and one intermediate resin and also to evaluate surface roughness after two preparation methods as well as bond failure mode. MATERIALS AND METHODS: In this in-vitro study forty-eight amalgam samples were randomly allocated to four groups. In Groups 1-3, specimens were sandblasted with 50 µm aluminum oxide, followed by application of Alloy primer in Groups 1 and 2. In Group 3 Alloy primer had not used. In Group 4, samples were prepared by silica coating using a silane coupling agent. Surface roughness analysis was performed in 10 additional samples after two surface treatments. The brackets in Group 1 were bonded with Transbond XT and those in other groups were bonded with Panavia V5. All specimens were examined for SBS following 5000 times thermocycling at 5°C-50°C. Modified adhesive remnant index was utilized for the bond failure mode. Data analysis was done by one-way analysis of variance, post hoc Tukey, Kruskal-Walli and Mann-Whitney U tests. Statistical significance was set at P < 0.05. RESULTS: The findings indicated the mean SBS were low (ranged from 0.19 to 4.66 MPa) and significantly lower in Group 3 than in Group 4 (P = 0.009). Bond failure occurred in adhesive/amalgam interface in nearly all samples. Silica coating produced significantly lower roughness than sandblast (P = 0.009). CONCLUSION: Silica coating had a significant higher bond strength than sandblast without application of Alloy primer. However compared to sandblast with Alloy primer, silica coating did not significantly improve the bond strength. Chemical bond between PanaviaV5 and sandblasted amalgam was not considerable.

Evaluation of Microleakage in Resin Composites Bonded to an Er:YAG Laser and Bur-Prepared Root and Coronal Dentin Using Different Bonding Agents.

Introduction: This study was conducted to assess the microleakage in Er:YAG laser-ablated and bur-prepared root and coronal dentin cavities using self-etch and total-etch adhesive systems. Methods: Sixty extracted caries-free human third molars were sectioned for dentin exposure. Then, two standard class V cavities were prepared in the root and coronal dentin of each tooth and allocated to one of the following conditioning groups randomly (n=12/Group): G1: Diamond bur for cavity preparation and single bond (BESB) etch-and-rinse adhesive for bonding, G2: Er:YAG laser (160 mJ, 20 Hz, 29.88 J/cm2) and SB (LESB), G3: Er:YAG laser and SB without acid etching (LSB), G4: Diamond bur and Clearfil SE Bond (BCSE) self-etch system, and G5: Er:YAG laser and Clearfil SE Bond (LCSE). The cavities were filled with Z100 composite resin. Dye penetration was assessed after thermocycling. Data analysis was done by Kruskal-Wallis and Mann-Whitney U tests. Statistical significance was set at P<0.05. Results: The results showed there were no statistically significant differences in microleakage between the two preparation methods (bur and laser) or the bonding agents applied (P>0.05). Regardless of the cavity preparation method, dye penetration was significantly higher in coronal dentin than in root dentin (P<0.05). Conclusion: The Er:YAG laser had the same efficacy as the conventional method for cavity preparation, and microleakage did not depend on the bonding agent. Microleakage was significantly higher in coronal restorations than in root restorations.

The Effect of Mechanical and Chemical Surface Preparation Methods on the Bond Strength in Repairing the Surface of Metal-Ceramic Crowns with Composite Resin: a Systematic Review and Meta-Analysis.

The aim of this study was to find the most effective surface preparation methods to enhance the bond strength between the composite resin and surface remaining from ceramic fracture. In this systematic review and meta-analysis, 39 studies were examined. The information related to the studies was extracted and categorized based on the type of the substrate material and applying or not applying thermal cycles (p<0.05). In the meta-analysis of substrate metal-ceramic samples without aging, application of air abrasion resulted in a significant increase of the bond strength to composite resin when using chemical compounds of the group without the mentioned functional monomers. Application of mechanical and chemical surface preparation methods can result in enhanced bond strength of the composite to the substrate material, which depends on the type of substrate material.

Knowledge of Laboratory Medicine in Medical Students: Is It Sufficient?

BACKGROUND & OBJECTIVE: Appropriate use of laboratory testing is essential for achieving safe and effective care to patient. Insufficient knowledge could lead to poor case management and increase the health care costs. It is believed that education on laboratory testing for undergraduate medical student is inadequate. This study was designed to evaluate the level of knowledge of 5 and 6 year undergraduate medical students in field of laboratory medicine. METHODS: Totally, 59 questions including 8 basic questions concerning individual assessment of their knowledge and 51 objective questions focusing on various stages of test ordering and interpretation were asked. RESULTS: Thirty seven undergraduate medical students at the level of internship participated. On average, 47.9% of students evaluated themselves as "weak" in 8 self-assessment questions. There was no significant difference between responders assessment on their own knowledge in various aspects of laboratory testing (P=0.184). In the objective questions regarding various stages of test ordering including pre-analytic, analytic and post analytic phases,45.6%,51.9% and 50% correct answers were reported ,respectively. Comparison of the level of the knowledge of the students regarding various stages of pathology testing did not show significant difference (P=0.638). CONCLUSION: Prioritizing an effective teaching method of laboratory medicine to medical students on appropriate time should be considered in medical school curriculum for better clinical decision making and optimal modern medical care.

Association of optic nerve sheath diameter in ocular ultrasound with prognosis in patients presenting with acute stroke symptoms.

BACKGROUND: Measurement of optic nerve sheath diameter (ONSD) by means of ocular ultrasound (US), can diagnose elevated intracranial pressure (ICP). Stroke accompanied by elevated ICP might have a worse prognosis. OBJECTIVE: To determine the relationship of ONSD in ocular US with prognosis in acute stroke in the emergency department (ED). METHODS: Patients with acute presentations of stroke, presenting to the ED in 2017 (during six months), were enrolled in our study. US exam was performed on all of them and ONSD was determined in two longitudinal and transverse dimensions. Demographic data, rate of patients' admission in the ward or intensive care unit, one-month patients' outcome and type of stroke were recorded. The relationship of mean ONSD was evaluated with study variables. RESULTS: In this study, 60 patients were enrolled. The mean ±â€¯SD ONSD in the deceased cases was 4.40 ±â€¯0.64 mm and in the survived patients was 3.83 ±â€¯0.56 mm. Youden index calculated ONSD>3.9 mm as the best cut-off point in mortality prognosis. It has a sensitivity of 83.3% and a specificity of 59.2%. CONCLUSIONS: Increased ONSD had a direct relationship with mortality rate in acute stroke.

The effect of washing water temperature on resin-dentin micro-shear bond strength.

BACKGROUND: The purpose of this study was to evaluate the effect of washing water temperature on the micro-shear bond strength (µSBS) of composite resin to dentin using a two-step etch-and-rinse system and a two-step self-etching system. MATERIALS AND METHODS: In this in vitro study, the intact dentins of buccal and lingual surfaces of healthy third molars were exposed. Dentin surfaces were rinsed with different temperatures of distilled water (20 s) before applying Single Bond (SB) or Clearfil SE Bond(SE). After applying the adhesive, composite cylinders (0.8 mm diameter and 1 mm length) were bonded to the teeth surfaces. After storing the specimens in 37°C distilled water for 48 h and thermocycling, µSBS test was done. Data were analyzed using analysis of variance, post hoc Tukey tests, paired samples t-test, and Fisher exact test (α = 0.05). RESULTS: Temperature and interaction of temperature and type of bonding agent affected the bond strength. The bond strength of SB groups was significantly higher at 50°C washing than 5°C (P = 0.003) and 22°C (P = 0.019), but no significant difference was observed between SE groups. The bond strength of SE was significantly higher at 22°C than that of SB (P = 0.031), whereas the bond strength of SB was significantly higher at 50°C than that of SE (P = 0.007). CONCLUSION: The use of high-temperature washing water is an appropriate method to enhance bond strength in etch-and-rinse systems.

Analgesic effect of paracetamol combined with low-dose morphine versus morphine alone on patients with biliary colic: a double blind, randomized controlled trial.

BACKGROUND: Numerous drugs have been proposed to alleviate pain in patients with biliary colic, especially opioids, but still there is a tendency to use less narcotics because of their side effects and the unwillingness of some patients. The present study aimed to compare the analgesic effect of paracetamol combined with low-dose morphine versus morphine alone in patients with biliary colic. METHODS: A randomized double-blind controlled trial was performed in 98 patients with biliary colic, recruited from two emergency departments from August 2012 to August 2013. Eleven patients were excluded and the remaining were randomized into two groups: group A received 0.05 mg/kg morphine+1 000 mg paracetamol in 100 mL normal saline and group B received 0.1 mg/kg morphine+normal saline (100 mL) as placebo. Pain scores were recorded using visual analogue scale (VAS) at baseline and 15 and 30 minutes after drug administration. Adverse effects and the need for rescue medication (0.75 µg/kg intravenous fentanyl) were also reported within 60 minutes of drug administration. RESULTS: Before the infusion, the mean±SD VAS scores were 8.73±1.57 in group A and 8.53±1.99 in group B. At 15 minutes after drug administration, the mean±SD VAS scores were 2.16±1.90 in group A vs. 2.51±1.86 in group B; mean difference was -0.35, and 95%CI -1.15 to 0.45 (P=0.38). At 30 minutes the mean±SD VAS scores were 1.66±1.59 in group A vs. 2.14±1.79 in group B; mean difference was -0.48, and 95%CI -1.20 to 0.24 (P=0.19). The mean pain scores in the two groups at 15 and 30 minutes demonstrated no significant difference. CONCLUSION: Paracetamol combined with low-dose morphine may be effective for pain management in patients with biliary colic.

Shear bond strength of resin composite bonded with two adhesives: Influence of Er: YAG laser irradiation distance.

BACKGROUND: Dental surfaces prepared with different Er:YAG laser distance may have different characteristics compared with those prepared with conventional instruments. The aim of this study was to investigate the effect of Er:YAG laser irradiation distance from enamel and dentin surfaces on the shear bond strength of composite with self-etch and etch and rinse bonding systems compared with conventional preparation method. MATERIALS AND METHODS: Two hundred caries-free human third molars were randomly divided into twenty groups (n = 10). Ten groups were designated for enamel surface (E1-E10) and ten for dentin surface (D1-D10). Er: YAG laser (2940 nm) was used on the E1-E8 (240 mJ, 25 Hz) and D1-D8 (140 mJ, 30 Hz) groups at four different distances of 0.5 (standard), 2, 4 and 11 mm. Control groups (E9, E10, D9 and D10) were ground with medium grit diamond bur. The enamel and dentin specimens were divided into two subgroups that were bonded with either Single Bond or Clearfil SE Bond. Resin composite (Z100) was dispensed on prepared dentin and enamel. The shear bond strengths were tested using a universal testing machine. Data were analyzed by SPSS12 statistical software using three way analysis of variance, Tukey and independent t-test. P < 0.05 was considered as significant. RESULTS: There was a significant difference between enamel and dentin substrates (P < 0.001) and between lased and un-lased groups; the un-lased group had significantly higher bond strength (P < 0.001). Shear bond strength increased significantly with an increase in the laser irradiation distance (P < 0.05) on enamel surfaces (in both bonding agent subgroups) and on dentin surfaces (in the Single Bond subgroup). CONCLUSION: Laser irradiation decreases shear bond strength. Irradiation distance affects shear bond strength and increasing the distance would decrease the negative effects of laser irradiation.

Emergency department nonurgent visits in Iran: prevalence and associated factors.

OBJECTIVES: To estimate the number of emergency department (ED) visits due to nonurgent problems and to describe the characteristics of those patients, as well as their reasons for presenting to the ED. STUDY DESIGN: Descriptive cross-sectional study. METHODS: In this study, all adult (aged >15 years) patients presenting to the ED over a 2-week period were evaluated. Data regarding the age, sex, marital status, educational level, and insurance status of all patients were recorded. The time and date of the presentation were also noted. Those classified by the triage nurse as having nonurgent conditions were surveyed regarding their reasons for presenting to the ED. RESULTS: Out of 1923 visits, 400 (20.8%) were classified as nonurgent. The prevalence of inappropriate ED visits was slightly greater in patients aged 15 to 49 years. Patients whose visits were paid for by health insurance accounted for the majority of inappropriate visits (82.75%). There were higher rates of inappropriate visits in the evening and night shifts compared with morning and afternoon shifts (17.39% vs 25.03%). The most common reason for presenting to the ED was "to obtain rapid treatment" (76.5%); only 10.75% presented because of a perceived urgent problem. CONCLUSIONS: The results of our study corroborate the previous findings that inappropriate use of the ED is common. The prevalence of presentation for nonurgent problems was substantive between 6 PM and 6 AM. Gender, marital status, education, insurance, and day of the week had no association with nonurgent presentation.

Fluoride release and bioactivity evaluation of glass ionomer: Forsterite nanocomposite.

BACKGROUND: The most important limitation of glass ionomer cements (GICs) is the weak mechanical properties. Our previous research showed that higher mechanical properties could be achieved by addition of forsterite (Mg2SiO4) nanoparticles to ceramic part of GIC. The objective of the present study was to fabricate a glass ionomer- Mg2SiO4 nanocomposite and to evaluate the effect of addition of Mg2SiO4 nanoparticles on bioactivity and fluoride release behavior of prepared nanocomposite. MATERIALS AND METHODS: Forsterite nanoparticles were made by sol-gel process. X-ray diffraction (XRD) technique was used in order to phase structure characterization and determination of grain size of Mg2SiO4 nanopowder. Nanocomposite was fabricated via adding 3wt.% of Mg2SiO4 nanoparticles to ceramic part of commercial GIC (Fuji II GC). Fluoride ion release and bioactivity of nanocomposite were measured using the artificial saliva and simulated body fluid (SBF), respectively. Bioactivity of specimens was investigated by Fourier transitioned-infrared spectroscopy (FTIR), scanning electronmicroscopy (SEM), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and registration of the changes in pH of soaking solution at the soaking period. Statistical analysis was carried out by one Way analysis of variance and differences were considered significant if P < 0.05. RESULTS: The results of XRD analysis confirmed that nanocrystalline and pure Mg2SiO4 powder was obtained. Fluoride ion release evaluation showed that the values of released fluoride ions from nanocomposite are somewhat less than Fuji II GC. SEM images, pH changes of the SBF and results of the ICP-OES and FTIR tests confirmed the bioactivity of the nanocomposite. Statistical analysis showed that the differences between the results of all groups were significant (P < 0.05). CONCLUSION: Glass ionomer- Mg2SiO4 nanocomposite could be a good candidate for dentistry and orthopedic applications, through of desirable fluoride ion release and bioactivity.