The Association between Dietary Inflammatory Index and Aging Biomarkers/Conditions: A Systematic Review and Dose-response Meta-analysis.

OBJECTIVES: We performed a current study to examine the association between dietary inflammatory index (DII) score and older age-related muscle conditions, including sarcopenia, low muscle mass, low muscle strength, frailty, and/or disability. DESIGN: Systematic review and dose-response meta-analysis. SETTING: A systematic literature search was performed using Scopus, PubMed/MEDLINE, and ISI Web of Science without limitation until October 04, 2022. Relative risk (RR) and 95% confidence interval (CI) were pooled by applying a random-effects model, while validated methods examined assess quality and publication bias via Newcastle-Ottawa Scale, Egger's regression asymmetry, and Begg's rank correlation tests respectively. A dose-response meta-analysis was conducted to estimate the RRs per 1-unit increment in DII scores. PARTICIPANTS: Adults (≥18 years). MEASURES: The risk of older age-related muscle conditions (sarcopenia, low muscle mass, low muscle strength, frailty, and/or disability). RESULTS: Data were available from 19 studies with 68079 participants. Results revealed that a higher DII score was significantly related to an increased risk of sarcopenia (RR=1.50; 95% CI: 1.26, 1.79; I2=53.3%; p<0.001; n=10; sample size =43097), low muscle strength (RR=1.47; 95% CI: 1.24, 1.74; I2=6.6%; p<0.001; n=4; sample size =9339), frailty (RR=1.61; 95% CI: 1.41, 1.84; I2=0.0%; p<0.001; study=5; participant=3882) and disability (RR=1.41; 95% CI: 1.16, 1.72; I2=58.4%; p=0.001; n=5; sample size =13760), but not low muscle mass (RR=1.24; 95% CI: 0.98, 1.56; I2=49.3%; p=0.069; n=4; sample size =11222). Additionally, results of the linear dose-response indicated that an increase of one point in the DII score was related to a 14% higher risk of sarcopenia, 6% higher risk of low muscle mass, 7% higher risk of low muscle strength, and a 7% higher risk of disability in adults. Non-linear dose-response relationships also revealed a positive linear association between the DII score and the risk of sarcopenia (Pnonlinearity = 0.097, Pdose-response<0.001), frailty (Pnonlinearity = 0.844, Pdose-response=0.010) and disability (Pnonlinearity = 0.596, Pdose-response=0.007). CONCLUSION: Adherence to a pro-inflammatory diet was significantly associated with a higher risk of sarcopenia and other age-associated adverse effects such as low muscle strength, disability, and frailty. These results indicate a necessity to prioritize the reduction of pro-inflammatory diets to help promote overall older age-related muscle conditions.

Controlled temperature-mediated curcumin release from magneto-thermal nanocarriers to kill bone tumors.

Systemic chemotherapy has lost its position to treat cancer over the past years mainly due to drug resistance, side effects, and limited survival ratio. Among a plethora of local drug delivery systems to solve this issue, the combinatorial strategy of chemo-hyperthermia has recently received attention. Herein we developed a magneto-thermal nanocarrier consisted of superparamagnetic iron oxide nanoparticles (SPIONs) coated by a blend formulation of a three-block copolymer Pluronic F127 and F68 on the oleic acid (OA) in which Curcumin as a natural and chemical anti-cancer agent was loaded. The subsequent nanocarrier SPION@OA-F127/F68-Cur was designed with a controlled gelation temperature of the shell, which could consequently control the release of curcumin. The release was systematically studied as a function of temperature and pH, via response surface methodology (RSM). The bone tumor killing efficacy of the released curcumin from the carrier in combination with the hyperthermia was studied on MG-63 osteosarcoma cells through Alamar blue assay, live-dead staining and apoptosis caspase 3/7 activation kit. It was found that the shrinkage of the F127/F68 layer stimulated by elevated temperature in an alternative magnetic field caused the curcumin release. Although the maximum release concentration and cell death took place at 45 °C, treatment at 41 °C was chosen as the optimum condition due to considerable cell apoptosis and lower side effects of mild hyperthermia. The cell metabolic activity results confirmed the synergistic effects of curcumin and hyperthermia in killing MG-63 osteosarcoma cells.

Factors Influencing Malaysian Men's Perceptions of Gender Equity in Family Planning.

INTRODUCTION: Various factors influence men's perceptions regarding gender equity in family planning (FP). Identifying these factors can contribute to a deeper understanding of the roles that men play in family planning and ultimately leads to women's reproductive health outcomes. OBJECTIVES: This paper aims to investigate factors influencing Malaysian men's perceptions of gender equity in family planning. To achieve this, the effects of sociodemographic characteristics (age, education, and marital status), masculine traits, and attitudes towards domestic violence are investigated. METHODOLOGY: This is a cross-sectional study undertaken by administrating questionnaires to a sample of 168 men in Malaysia. The data are analyzed by applying partial least squares-structural equation modeling (PLS-SEM) and by using WarpPLS 6.0. RESULTS: The results confirmed the significant effects of masculine traits and attitudes supporting domestic violence on perceived gender equity in family planning. In other words, the results showed that men's masculine traits and attitudes supporting domestic violence negatively influenced gender equity in family planning. The hypothesized effects of sociodemographic characteristics on perceived gender equity in family planning could not be verified. CONCLUSIONS: This study suggests some practical implications for local authorities to implement interventions that take a gender transformative approach to reduce men's masculine traits and improve their attitudes towards domestic violence to enhance gender equity in family planning.

Internal dosimetry studies of 170Tm-EDTMP complex, as a bone pain palliation agent, in human tissues based on animal data.

Radiopharmaceuticals with therapeutic applications are designed to deliver high doses of radiation to target organs with minimizing unwanted radiation to healthy tissues. Owing to the potential of targeted radiotherapy to treat a wide range of malignancies, 170Tm -EDTMP was developed for possible therapeutic applications. This study describes absorbed dose prediction of 170Tm-EDTMP in human organs after animal injection which is determined via medical internal radiation dose (MIRD) and MCNP-4C code methods. It was estimated that a 1-MBq administration of 170Tm-EDTMP into the human body would result in an absorbed dose of 37.9 mGy (MIRD method) and 38.02 mGy (MCNP-4C code) in the bone surface after 60 days post injection. Highest and lowest difference between MIRD and MCNP results are for lung and bone surface respectively. Finally, the results show that there is a good agreement between MIRD method and MCNP-4C simulation code for absorbed dose estimation.

The Effects of Concurrent Training Order on Satellite Cell-Related Markers, Body Composition, Muscular and Cardiorespiratory Fitness in Older Men with Sarcopenia.

OBJECTIVES: Concurrent Training (CT) is described as a combination of resistance training (RT) and endurance training (ET) in a periodized program to maximize all aspects of physical performance. To date, effects of CT order on muscular and cardiorespiratory fitness adaptations are controversial. Owing to the age-related decrement in satellite cells (SC) which are critical for fiber repair, conservation, muscle hypertrophy as well as cardiorespiratory fitness, the present study examined the response of SC related markers to CT order in older sarcopenic men. PARTICIPANTS: Thirty older men (age= 64.3 ± 3.5 years) were randomly assigned into one of 3 groups, ET followed by RT (E+R; n=10), RT followed by ET (R+E; n= 10) or a control (C; n=10). INTERVENTION: The training protocol consisted of 3 exercise sessions per week for 8 weeks. Blood samples were obtained at baseline and 48 hours after the final training session. RESULTS: Weight, skeletal muscle mass, lower and upper body power, maximal oxygen consumption (VO2max), Paired Box 7 (Pax7), and Myogenic factor 5 (Myf5) significantly increased, while were percent body fat significantly decreased following E+R and R+E compared to C. Importantly, the improvement in skeletal muscle mass, lower and upper body power, Myf5 and Pax7 in the E+R was significantly greater than the R+E group. Myogenin (Myog) and Paired Box 3 (Pax3) significantly increased (P < 0.01) in both training groups compared to no changes in C. CONCLUSION: An 8-week CT intervention improves SC related markers, body composition and enhances power and VO2max in older sarcopenic participants, regardless of the order of RT and ET. However, performing ET before RT may be more effective at enhancing skeletal muscle mass, Myf5 and Pax7, in addition to both lower and upper body power. While both CT programs produced notable physiological and performance benefits, performing ET before RT during CT may provide the greatest therapeutic benefits for aging individuals.

Physical Properties of Nanohybrid and Microhybrid Resin Composites Subjected to an Acidic Environment: A Laboratory Study.

BACKGROUND: This study investigated the hardness and color stability of five resin composites subjected to different polishing methods following immersion in distilled water or lactic acid for up to three months. METHODS AND MATERIALS: Three nanohybrid, Paradigm (3M ESPE), Estelite Sigma Quick (Tokuyama), Ice (SDI), and two microhybrid, Filtek P60 and Filtek Z250, composites were examined. Disc-shaped specimens (10×1.5 mm) were prepared and immersed in distilled water for 24 hours then polished using either silicon carbide paper, the Shofu polishing system or were left unpolished (control). The CIE values and microhardness were determined using a spectrophotometer and digital Vickers hardness tester, respectively (n=10) after one, 45, and 90 days of storage in distilled water or lactic acid. Data were analyzed using analysis of variance, Tukey test, and Pearson correlation coefficient. RESULTS: Ice exhibited the greatest color change, yet Paradigm and Filtek P60 demonstrated the least. Overall, discoloration of tested materials was multifactorial and the effect of storage media depended on the material, polishing method and time interval. The greatest hardness was obtained for Paradigm and the lowest for Estelite. Hardness was found to be significantly higher in lactic acid after 45 days (p=0.014) and even higher after 90 days (p<0.001) compared with distilled water. CONCLUSIONS: An acidic environment did not adversely affect color stability or microhardness of the resin composites. There was a significantly mild reverse correlation between hardness and color change in both storage media.

Overexploitation hazards and salinization risks in crucial declining aquifers, chemo-isotopic approaches.

Bastam region is overusing its groundwater resources stocks. The groundwater levels, and hydrogeochemical data during a 14-year period (2002-2016) and isotopic composition (2016) of the 22 groundwater samples were investigated to determine the hydrogeological regime of Bastam Plain and identify the geochemical processes that control the groundwater quality. This plain is situated in a semi-arid region of northern Iran, mainly recharging from the carbonate Mountains in the north and southwest. In general, overexploitation of the groundwater due to low precipitation and changing precipitation regime has destructive effects on the hydrogeological setting and flow regime of Bastam crucial aquifer, including the decline of the groundwater level with rate of 0.9 m/year, water storage deficit of 17.32 Mm3/year and consequently, the intrusion of saline water towards the aquifer from the western and eastern salty plains. Based on the EC values, the groundwater samples divided into three groups of fresh waters with EC < 1000 µS/cm and Ca-Mg-HCO3 water type which are located in the recharge zones, semi-saline waters (1000 < EC < 2500 µS/cm) with Na-Mg-Cl-SO4 type at the center and saline waters with EC values more than 2500 µS/cm and Na-Cl type in the eastern and western parts of the plain. A few groundwater samples (group 2) fall on the mixing line between fresh and saline water in Piper diagram during the saline water intrusion, but most of the samples depart from this mixing line, indicating water-rock interactions in this area, resulting in deficit of Na+ and surplus of Ca2+ concentration. The fresh water samples cluster along the local meteoric water line in δ18O and δ2H relationships, suggesting an integrative and rapid recharge with meteoric water. Hydrochemical and isotopic characteristics indicate that invasion of the saline water resulted from halite dissolution with minor evaporation in the surrounding salty playas is the main origin for the increasing salinity in the Bastam aquifer. The salinization risks limit the groundwater withdrawals from Bastam aquifer in some areas, threatening the future sustainable development of the region.

Urokinase-plasminogen activator protects periodontal ligament fibroblast from oxidative induced-apoptosis and DNA damage.

BACKGROUND AND OBJECTIVE: Urokinase-plasminogen activator (uPA) is a serine protease expressed at high basal level in normal gingival cervical fluid. Despite its known pathologic role in tissue proteolysis in periodontitis, little is known concerning uPA physiological function in oral tissue. Recent evidence in cancer cells has implicated the uPA system in DNA repair and anti-apoptotic pathways. This study is aimed to evaluate the protective function of urokinase against oxidative DNA damage in periodontal ligament (PDL) fibroblast, and to propose a new biological role for uPA in oral cavity. MATERIAL AND METHODS: PDL cells were isolated from human wisdom teeth obtained from healthy donors. An oxidative stress model was created in which PDL cells were incubated with 20, 30, 40 and 60 µmol/L hydrogen peroxide. Twenty-four hours before and after peroxide treatment, cells were treated with uPA and amiloride. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide assay, apoptosis by DAPI-staining and annexin V/propidium iodide assay, and DNA breaks by alkaline comet assay. For estimating DNA damage level, γ-H2AX expression was studied using flow cytometry and immunostaining. RESULTS: The incubation of the peroxide-treated cells with uPA significantly increased cell viability and decreased apoptosis. A significant decrease in the number of γ-H2AX foci was seen at 30 µmol/L hydrogen peroxide in uPA-treated cells. uPA inhibition as a result of amiloride treatment, in turn, induced a reduction in cell viability. In addition, there was a significant decrease in the levels of DNA damage in uPA-treated groups as measured by the comet assay. CONCLUSION: The present study brings support to the theory that uPA may have a protective role for periodontal tissue and could protect PDL fibroblasts from oxidative DNA damage and apoptosis.

Fracture Toughness of Nanohybrid and Hybrid Composites Stored Wet and Dry up to 60 Days.

STATEMENT OF PROBLEM: Patients' demand for tooth-colored restoratives in the posterior region is increasing. Clinicians use universal nanohybrid resin composites for both anterior and posterior regions. There are few published reports comparing fracture toughness of nonohybrids and that of hybrid composite stored wet and dry. OBJECTIVES: To investigate the fracture toughness of three nanohybrids compared to that of a hybrid resin composite stored dry or wet up to 60 days, using four-point bending test. MATERIALS AND METHODS: Four resin composites were used: three nanohybrids; Filtek Supreme (3M), Ice (SDI), TPH3 (Dentsply) and one hybrid Filtek P60 (3M). For each material, 40 rectangular notched beam specimens were prepared with dimensions of 30 mm × 5mm × 2mm. The specimens were randomly divided into 4 groups (n = 10) and stored at 37ºC either in distilled water or dry for 1 and 60 days. The specimens were placed on the four-point test jig and subjected to force (N) using universal testing machine loaded at a crosshead speed of 0.5mm/min and maximum load at specimen failure was recorded and KIC was calculated. RESULTS: Three-way ANOVA showed a significant interaction between all the factors (all p < .0001). Except for TPH3, all tested materials showed significantly higher KIC when stored dry than stored wet (p < 0.05). After 1 day of dry storage, Ice showed the highest KIC (2.04± 0.32) followed by Filtek P60 and the lowest was for Filtek Supreme (1.39± 0.13) The effect of time on fracture toughness was material dependent. CONCLUSIONS: Wet storage adversely affected the fracture toughness of almost all materials. Keeping the restoration dry in the mouth may increase their fracture toughness. Therefore, using a coating agent on the surface of restoration may protect them from early water uptake and increase their strength during a time period.

Effect of a self-adhesive coating on the load-bearing capacity of tooth-coloured restorative materials.

BACKGROUND: The aim of this study was to compare the flexural strength and Vickers hardness of tooth-coloured restorative materials with and without applying a self-adhesive coating for up to 6 months. METHODS: Specimens were prepared from three resin composites (RC), two resin-modified glass-ionomer cements (RM-GIC) and two conventional glass-ionomer cements (CGIC). All materials were tested both with and without applying G-Coat Plus (GCP). Specimens were conditioned in 37 °C distilled deionized water for 24 h, and 1, 3 and 6 months. The specimens were strength tested using a four-point bend test jig in a universal testing machine. The broken specimen's halves were used for Vickers hardness testing. Representative specimens were examined under an environmental scanning electron microscope. RESULTS: Data analysis showed that regardless of time and materials, generally the surface coating was associated with a significant increase in the flexural strength of the materials. Applying the GCP decreased the hardness of almost all materials significantly (P < 0.05) and effect of time intervals on hardness was material dependent. CONCLUSIONS: The load-bearing capacity of the restorative materials was affected by applying self-adhesive coating and ageing. The CGIC had significantly higher hardness but lower flexural strength than the RM-GIC and RC.

Effect of calcium phosphate addition to fluoride containing dental varnishes on enamel demineralization.

BACKGROUND: The aim of this study was to evaluate the ability of calcium phosphate and fluoride containing varnishes to inhibit enamel demineralization. METHODS: Six varnishes were selected for analysis: (1) Enamel Pro containing amorphous calcium phosphate; (2) Clinpro White containing functionalized tricalcium phosphate (fTCP); (3) MI Varnish containing casein phosphopeptide-stabilized amorphous calcium phosphate (CPP-ACP); (4) Duraphat (first no added calcium control); (5) Profluorid (second no added calcium control); and (6) placebo (no added calcium or fluoride control). Human enamel slabs (36) were each cut into half-slabs and covered with one of the six dental varnishes to create a window. The half-slabs were then individually immersed in a polyacrylate demineralization buffer pH 4.8 for four days at 37 °C with a change of solution each day. Mineral content was determined using transverse microradiography. RESULTS: All fluoride-containing varnishes significantly inhibited enamel demineralization when compared with the placebo varnish. However, out of the calcium phosphate and fluoride containing varnishes only MI Varnish, containing fluoride and CPP-ACP was superior to the fluoride-alone varnishes. MI Varnish also released the highest levels of calcium, phosphate and fluoride ions. CONCLUSIONS: MI Varnish containing fluoride and CPP-ACP was superior to the other varnishes in protecting against enamel demineralization.

Fracture strength of root filled premolar teeth restored with silorane and methacrylate-based resin composite.

OBJECTIVES: To compare fracture characteristics of root-filled teeth with variable cavity design restored with a low shrinkage silorane and methacrylate-based resin composite. METHODS: 77 extracted maxillary premolars were divided randomly into seven groups: (Group 1) intact teeth; (Groups 2-4) MOD plus endodontic access with the buccopalatal width of the occlusal isthmus equals one third of the intercuspal width; (Groups 5-7) MOD plus endodontic access with the buccopalatal width of the occlusal isthmus equals one half of the intercuspal width. Groups 2 and 5 were left unrestored, Groups 3 and 6 were restored with a silorane-based resin composite (Filtek P90) and Groups 4 and 7 with a methacrylate-based resin composite (Z250). Teeth were loaded in a universal testing machine; load and fracture patterns were recorded and compared statistically using 2-way ANOVA and t-test for pairwise comparisons and 1-way ANOVA with Dunnett test for multiple comparisons. RESULTS: Unrestored teeth became progressively weaker with more extensive preparations, Group 5 (unfilled ½) showed the lowest fracture load among the groups (71±22N, P<0.001). Restorations increased the fracture strength of unrestored teeth regardless of cavity size (P<0.001), but was still significantly weaker than sound teeth, with no significant difference between silorane and methacrylate groups. Failure of restored teeth was mostly adhesive at the tooth restoration interface. CONCLUSIONS: Silorane-based resin composite have no superior strengthening effect over the conventional methacrylate-based resin composite in restoration of root filled teeth. Both materials showed similar fracture patterns. CLINICAL SIGNIFICANCE: Root filled teeth are considerably weakened via restorative and endodontic procedures. A direct adhesive restoration will aid in preserving tooth structure as far as it provides enough strength.

Oral health-related quality of life of removable partial denture wearers and related factors.

This study aims to investigate the oral health-related quality of life (OHRQoL) in a group of removable partial denture (RPD) wearers in Shiraz (Iran), using the Persian version of the Oral Health Impact Profile (OHIP-14). Two hundred removable partial denture wearers had completed a questionnaire regarding patients' demographic characteristics and denture-related factors. In addition, the OHIP-14 questionnaire was filled out by interviewing the patients. Two measures of interpreting the OHIP-14 scales were utilised: OHIP-14 sum and OHIP-14 prevalence. The relationship of the patients' demographic characteristics and denture-related factors, with their OHRQoL was investigated. The mean OHIP-14 sum and OHIP-14 prevalence of RPD wearers were 13·80 (±10·08) and 44·5%, respectively. The most problematic aspects of OHIP-14 were physical disability and physical pain. Twenty-seven percentage and 24% of participants had reported meal interruption and eating discomfort, respectively. OHIP-14 prevalence and OHIP-14 sum were found to be significantly associated with factors representing RPD wearer's oral health such as self-reported oral health and frequency of denture cleaning. Furthermore, OHIP-14 prevalence and OHIP-14 sum were significantly associated with factors related to frequency of denture use such as hours of wearing the denture during the day and wearing the denture while eating and sleeping. Therefore, it can be concluded that the OHRQoL of the patients of the study was generally not optimal and found to be strongly associated with oral health.

Effect of a home bleaching agent on the fracture toughness of resin composites, using short rod design.

STATEMENT OF PROBLEM: Resin composites are brittle materials and their major shortcomings are manifested in their sensitivity to flaws and defects. Although various mechanical properties of resin composites have been described, few studies are available on assessing the effect of bleaching agents on resin composites using the short rod design. PURPOSE: To place various resin composites into distilled water at 37°C for 21 days and determine the effect of immersion time in distilled water, with and without exposure to 10% carbamide peroxide by employing short rod design fracture toughness test. MATERIALS AND METHOD: Specimens were prepared from three resin composites; Rok (SDI), Esthet (Dentsply), and Estelite (Tokuyama). For each material, a total of 24 disc-shaped specimens were prepared using a custom-made mould. Specimens were randomly divided into 3 groups of 8 and conditioned in 37°C distilled water for either 24 hours, or 21 days. 21 day specimens were tested both with and without applying bleaching agent; Polanight (SDI). Study group specimens were bleached for 21 days, 2 hours a day. The specimens were loaded using a universal testing machine with a crosshead speed of 0.5 mm per minute. The maximum load at specimen failure was recorded and the KIc (MPa. M (0.5)) was calculated. RESULTS: Statistical analysis using two-way ANOVA showed a significant relationship between material and time (p< 0.05).Tukey's test showed that after 24 h of immersion in distilled water, Rok revealed the highest KIc followed by Esthet and Estelite. The bleaching agent significantly improved the fracture toughness values of Esthet while it decreased that of Estelite. CONCLUSION: The fracture toughness of the resin composites was affected by the bleaching agent and distilled water. In comparison with Rok and Estelite, fracture toughness of Esthet was increased due to aging and application of bleaching agent.

Application of artificial neural networks for optimization of preparation of insulin nanoparticles composed of quaternized aromatic derivatives of chitosan.

The aim of this research was to develop an artificial neural network (ANN) in order to design a nanoparticulate oral drug delivery system for insulin. The pH of polymer solution (X1), concentration ratio of polymer/insulin (X2) and polymer type (X3) in 3 level including methylated N-(4-N,N- dimethyl aminobenzyl) chitosan, methylated N-(4-pyridinyl) chitosan, and methylated N-(benzyl) chitosan are considered as the input values and the particle size, zeta potential, PdI, and entrapment efficiency (EE %) as output data. ANNs are employed to generate the best model to determining the relationships between input and response values. In this research, a multi-layer percepteron with different topologies has been tested in order to define the one with the best accuracy and performance. The optimization was used by minimizing the error between the predicted and observed values. Three training algorithms (Levenberg-Marquardt (LM), Bayesian-Regularization (BR), and Gradient Descent (GD)) were employed to train ANNs with various numbers of nodes, hidden layers and transfer functions by random selection. The accuracy of prediction data were assayed by the mean squared error (MSE).The ability of all algorithms was in the order: BR>LM>GD. Thus, BR was selected as the best algorithm.

Molar-incisor hypomineralisation: a prevalence study amongst primary schoolchildren of Shiraz, Iran.

AIM: To investigate the prevalence of molar-incisor hypomineralisation (MIH) amongst primary schoolchildren of Shiraz, Iran, taking into account the possible influence of biographic and socio-demographic parameters. STUDY DESIGN AND METHODS: A randomised cluster sample of 9- to 11-year-old children (N = 810) had their first permanent molars and incisors (index teeth) evaluated using the European Academy of Paediatric Dentistry criteria for MIH. The examinations were conducted at schools by a calibrated examiner. Prevalence of MIH was assessed based on biographic and socio-demographic parameters including area of residency, school type, father's level of education, weight-for-age and height-for-age. RESULTS AND STATISTICS: Of the children examined, 164/810 (20.2%) had MIH and 53.7% of them presented with MIH lesions in all first molars. Mild defects represented by demarcated yellow brown opacities comprised 35.5% of the total MIH lesions. The prevalence of MIH was significantly greater in girls, children with healthy body weight and height, those whose fathers did not have a tertiary education and from families of low socio-economic status. Regression analyses indicated that none of the biographic and socio-demographic variables represented a significant risk factor in the occurrence of MIH except for body weight. Obesity was negatively correlated to MIH (OR = 0.45; 95% CI 0.25-0.82). CONCLUSIONS: The prevalence of MIH in a group of Iranian children was 20.2%. Biographic and socio-demographic parameters appeared to have no significant correlation with MIH except body weight, which warrants further research.

Size tuning of Ag-decorated TiO2 nanotube arrays for improved bactericidal capacity of orthopedic implants.

Surface modification of orthopedic implants using titanium dioxide nanotubes and silver nanoparticles (SNs) is a promising approach to prevent bacteria adhesion, biofilm formation, and implant infection. Herein, we utilized a straightforward and all-solution process to prepare silver-decorated TiO2 nanotube arrays with surface density of 10(3) to 10(4) per µm(2). With controlling the synthesis conditions, hexagonal closed-packed nanotubes with opening diameter of 30-100 nm that are decorated with SNs with varying sizes (12-40 nm) were prepared. Various analytical techniques were utilized to characterize the size, morphology, distribution, valance state, surface roughness, and composition of the prepared antibacterial films. The bactericidal capacity of the films were studied on Escherichia coli (E. coli) by drop-test method and correlated with the size and percentage of Ag as well as the surface density of TiO2 nanotube arrays. Synergetic effect of TiO2 nanotubes and SNs on the antibacterial activity of the composite films is shown. The bactericidal capacity is found to depend on the size characteristics of the Ag-TiO2 coating. The highest antibacterial activity is obtained for TiO2 nanotubes with opening diameter of about 100 nm and SNs with an average size of 20 nm. MTT assay using osteoblast MG63 cells was performed to examine the cell viability. We suggest that release rate of the silver ions is an important factor controlling the antibacterial activity. Additionally, the size dependency of the bactericidal capacity implies that electrical coupling between silver and TiO2 nanotubes and improved hydrophobicity of the coating might influence the bacterial behavior of the hybrid nanostructures.

Effect of G-Coat Plus on the mechanical properties of glass-ionomer cements.

BACKGROUND: Although various mechanical properties of tooth-coloured materials have been described, little data have been published on the effect of ageing and G-Coat Plus on the hardness and strength of the glass-ionomer cements (GICs). METHODS: Specimens were prepared from one polyacid-modified resin composite (PAMRC; Freedom, SDI), one resin-modified glass-ionomer cement; (RM-GIC; Fuji II LC, GC), and one conventional glass-ionomer cement; (GIC; Fuji IX, GC). GIC and RM-GIC were tested both with and without applying G-Coat Plus (GC). Specimens were conditioned in 37 °C distilled water for either 24 hours, four and eight weeks. Half the specimens were subjected to a shear punch test using a universal testing machine; the remaining half was subjected to Vickers Hardness test. RESULTS: Data analysis showed that the hardness and shear punch values were material dependent. The hardness and shear punch of the PAMRC was the highest and GIC the lowest. Applying the G-Coat Plus was associated with a significant decrease in the hardness of the materials but increase in the shear punch strength after four and eight weeks. CONCLUSIONS: The mechanical properties of the restorative materials were affected by applying G-Coat Plus and distilled water immersion over time. The PAMRC was significantly stronger and harder than the RM-GIC or GIC.

Film thickness and flow properties of resin-based cements at different temperatures.

STATEMENT OF PROBLEM: For a luting agent to allow complete seating of prosthetic restorations, it must obtain an appropriate flow rate maintaining a minimum film thickness. The performance of recently introduced luting agents in this regard has not been evaluated. PURPOSE: To measure and compare the film thickness and flow properties of seven resin-containing luting cements at different temperatures (37°C, 25°C and10°C). MATERIAL AND METHODS: Specimens were prepared from five resin luting cements; seT (SDI), Panavia F (Kuraray), Varioloink II (Ivoclar), Maxcem (Kerr), Nexus2 (Kerr) and two resin-modified glass-ionomer luting cements (RM-GICs); GC Fuji Plus (GC Corporation), and RelyX Luting 2 (3 M/ESPE). The film thickness and flow rate of each cement (n=15) was determined using the test described in ISO at three different temperatures. RESULTS: There was a linear correlation between film thickness and flow rate for most of the materials. Cooling increased fluidity of almost all materials while the effect of temperature on film thickness was material dependent. At 37°C, all products revealed a film thickness of less than 25µm except for GC Fuji Plus. At 25°C, all cements produced a film thickness of less than 27 µm except for seT. At 10°C, apart from seT and Rely X Luting 2, the remaining cements showed a film thickness smaller than 20 µm. CONCLUSION: Cooling increased fluidity of almost all materials, however. the film thickness did not exceed 35 µm in either condition, in spite of the lowest film thickness being demonstrated at the lowest temperature.