Nail Polish Research Articles

Bacterial sealing ability of calcium silicate-based sealer for endodontic surgery: an in-vitro study

BackgroundApical surgery with standard retrograde maneuvers may be challenging in certain cases. Simplifying apical surgery to reduce operating time and streamline retrograde manipulation is an emerging need in clinical endodontics.Aim of the studyThe aim of the study was to compare the bacterial sealing ability of a calcium silicate-based sealer with the single cone technique combined with root end resection only, and calcium silicate-based sealer as a retrograde filling versus MTA retrofilling, and to analyze bacterial viability using confocal laser scanning microscope (CLSM).Materials and methodsIn this in vitro experimental study, 50 extracted human maxillary incisor teeth were instrumented and randomly divided into five groups: three experimental groups, a positive control group, and a negative control group (n = 10/group). In the experimental groups, the roots were obturated using the single cone technique (SCT) and a calcium silicate-based sealer. In group 1, the roots were resected 3 mm from the apex with no further retrograde preparation or filling. In groups 2 and 3, the roots were resected, retroprepared, and retrofilled with either a calcium silicate-based sealer or MTA, respectively. Group 4 (positive control) was filled with a single gutta-percha cone without any sealer. In group 5 (negative control), the canals were left empty, and the roots were sealed with wax and nail varnish. A bacterial leakage model using Enterococcus faecalis was employed to assess the sealing ability over a 30-day period, checking for turbidity and analyzing colony forming units (CFUs) per milliliter. Five specimens from each group were examined using CLSM for bacterial viability. Data for the bacterial sealing ability were statistically analyzed using chi-squared and Kruskal-Wallis tests.ResultsThe three experimental groups did not show significant differences in terms of bacterial leakage, or bacterial counts (CFUs) (P > 0.05). However, significant differences were observed when comparing the experimental groups to the positive control group. Notably, the calcium silicate-based sealer, when used as a retrofilling, yielded the best sealing ability. CLSM imaging revealed viable bacterial penetration in all the positive control group specimens while for the experimental groups, dead bacteria was the prominent feature seen.ConclusionWithin the limitations of this study, it could be concluded that the bacterial sealing ability of calcium silicate-based sealer with the single cone technique combined with root end resection only and calcium silicate-based sealer as a retrograde filling were comparable with MTA retrofilling during endodontic surgical procedures.

Depth-resolved elemental and molecular analysis of polymeric multilayers with EI-MS and ICP-OES using chemometric evaluation

Polymeric composite materials with layered structures have increasingly gained importance as, for specific applications, the required properties cannot be achieved with one single material; thus, for example, multi-layer polymers or special surface coatings are employed.None of the conventionally available techniques enables a comprehensive characterization of composite materials, including depth-resolved information about their organic and elemental constituents.In this work, a previously introduced approach enabling the direct characterization of the organic and inorganic constituents of solid polymer samples was further developed and optimized for depth profiling analysis of stacked layer polymers. For this purpose, the ablation chamber’s washout behavior and transfer line’s transport efficiency were improved. Chemometric methods were applied for the data analysis to gain greater insight and enable more precise differentiation, comparison and classification.The work investigates the feasibility of the developed approach by analyzing a multi-layer stacked polymer sample created from nail polishes and using cluster analysis on the data collected with the bimodal detection. The layers of the sample could be differentiated by their organic and elemental constituents’ fingerprints, achieving a depth resolution of 7 µm.

Letter in reply to: Nail polish used by healthcare personnel does not increase the rate of healthcare-associated infections.

Letter in reply to: Nail polish used by healthcare personnel does not increase the rate of healthcare-associated infections.

Assessing the Risk of Organophosphate Esters from Nail Polish: Indoor Emissions, Fate Modeling, and Health Risk Assessment

Assessing the Risk of Organophosphate Esters from Nail Polish: Indoor Emissions, Fate Modeling, and Health Risk Assessment

Assessment of Nanosilver Fluoride Application on the Microtensile Bond Strength of Glass Ionomer Cement and Resin-modified Glass Ionomer Cement on Primary Carious Dentin: An In Vitro Study.

Nanosilver sodium fluoride (NSF) has recently gained popularity in dentistry as an alternative to silver diamine fluoride (SDF) due to its drawbacks of staining the tooth black and possibly causing soft tissue injury, which has been eliminated in NSF due to the nanoparticle size of silver. This study aims to assess the microtensile bond strength of glass ionomer cement (GIC) and resin-modified glass ionomer cement (RMGIC) with pretreatment of NSF on extracted primary carious teeth. Teeth were stored in 10% formalin. The roots were severed, and the pulp chambers were cleaned. The occlusal enamel was ground, reducing the dentin thickness by 1 mm. The specimens were covered with nail varnish, leaving only the area of flat dentin exposed. Caries were induced microbiologically by inoculating Streptococcus mutans. Group I-NSF with GIC restoration, group II-NSF with RMGIC restoration, group III-restoration with GIC, and group IV-restoration with RMGIC. After different surface treatments of the carious dentin were performed, each specimen was placed in the testing jig of a universal testing machine and stressed in tension at a crosshead speed of 1 mm/minute until bond failure was observed. They were air-dried and placed under a scanning electron microscope. The failure modes-adhesive, cohesive, and mixed failure were recorded for statistical evaluation. Maximum results of microtensile bond strength were seen in the pretreatment group with NSF sealant, followed by RMGIC restoration, and the least results were observed in the conventional GIC restoration group. Of all the types of failures in our study, adhesive was the maximum type. The microtensile bond strength of pretreatment with NSF showed higher values when compared to conventional restorations of GIC and RMGIC. The failure modes in each group were not significantly varied. Pretreatment with NSF will prevent secondary caries formation, and the restorations will also be stronger. Das A, Ramamurthy N, Srinivasan I, et al. Assessment of Nanosilver Fluoride Application on the Microtensile Bond Strength of Glass Ionomer Cement and Resin-modified Glass Ionomer Cement on Primary Carious Dentin: An In Vitro Study. Int J Clin Pediatr Dent 2024;17(5):565-569.

LEAF ANATOMICAL ADAPTATIONS OF FOURTEEN TREE SPECIES GROWING IN LAGOS STATE UNIVERSITY, OJO CAMPUS. LAGOS, NIGERIA

Plants growing in different locations exhibit various anatomical adaptations which make them survive in their various habitats. Therefore, this study examined the leaf anatomical adaptations of fourteen tree species namely Acacia auriculiformis, Albizia lebbeck, Anacardium occidentale, Azadirachta indica, Carica papaya, Delonix regia, Gmelina arborea, Lagestroemia speciosa, Mangifera indica, Polyalthia longifolia, Tectona grandis, Terminalia catappa, Terminalia ivoriensis and Yucca gigantea growing in Lagos State University, Ojo Campus.. The leaf epidermal layers were isolated using nail polish; and were observed under the light microscope to determine the stomata features, epidermal cell and trichome types. The results showed that all the species were hypostomatic, with the exception of Acacia auriculiformis and Terminalia ivorensis that were amphistomatic. Eight stomatal complex types such as anomotetracytic, staurocytic, anisosytic, brachyparacytic, paracytic, pericytic, brachyparatetracytic and anomocytic were observed among the species. The stomatal density ranged from 46.05 mm-2 342.11 mm-2 on both leaf surfaces. The stomatal index ranged from 16.17% - 91.23% on both leaf surfaces. Trichomes were found in Albizia lebbeck, Delonix regia, Gmelina arborea, Polyalthia longifolia, Tectona grandis and Terminali aivorensis. The anticlinal cell wall patterns observed were round, curved, wavy and straight; while the epidermal cell shapes were irregular, isodiametric and polygonal. This study revealed that leaf anatomical adaptations such as amphistomatic leaf type, presence of stomatal complex types (anomocytic, anomotetracytic, brachyparatetracytic, staurocytic and anisocytic) with many subsidiary cells; high stomatal density and index; absence of trichomes; and wavy anticlinal cell wall pattern might be responsible for survival of the species in their locations.

Discussion Abounds on the Potential Carcinogenic Risks Associated With the Use of UV Curing Lamps for Permanent Nail Polish

BackgroundControversy has recently broken out over the potential carcinogenic risk associated with exposure to UV lamps for permanent nail polish. The new LED-based polymerization devices, and their potential biological effect has not been analyzed to this date. ObjectiveTo evaluate the emission power and its potential biological effects on the skin of 2 types of UV LED and fluorescent curing lamps under normal use conditions compared to doses of sunlight exposure. Material and methodsThe emission spectrum (290nm to 450nm) of curing lamps and the Sun at noon on an average summer day in mid-latitude Spain was analyzed. The effective biological irradiance potential for erythema, non-melanoma skin cancer, DNA damage, photoimmunosuppression and permanent pigmentation was also characterized. ResultsThe high-energy UVA-visible irradiance emitted by these devices was similar to the one coming from the Sun in that spectral range while the effective biological doses were lower or similar to those also coming from the Sun. The total UV and high-energy visible dose per manicure session corresponded to that obtained from 3.5min to 6min exposures to the Sun at noon in the summer days at our latitudes. ConclusionsThe exposure times and doses received with the common use of artificial lamp nail drying correspond to sunlight exposures of 3min to 5min in the central hours of the day. This represents a very low carcinogenic potential compared to sunlight exposure, although similar regarding immunosuppressive potential. Photoprotective measures would further minimize the risks.

Artificial nail modelling systems in healthcare workers: An emerging risk of contact sensitization to a well-known occupational allergen in an alternative way.

Artificial nail modelling systems (ANMS) pose a significant risk for nail stylists and their clients regarding acrylate sensitization, which might jeopardize the use of acrylate-containing medical devices. To evaluate the frequency of artificial nail practices among female healthcare workers (HCWs) compared with controls and assess ANMS-related side effects. In this comparative, cross-sectional, single-centre study, a face-to-face interview with 200 female HCWs and 200 age-matched female dermatology patients (controls) was conducted regarding the use of ANMS between March and November 2023. Among 400 participants (median age: 25), 85 (21.3%) have applied ANMS at least once. The prevalence of ANMS application was significantly higher in HCWs (n = 54/200, 27%) compared with controls (n = 31/200, 15.5%) (p < 0.05). Long-lasting nail polish was the most commonly preferred technique (n = 82/85, 96.5%). ANMS were mainly performed in nail studios by nail stylists (n = 79/85, 92.9%), while three participants were using home kits. Nail brittleness was the most frequently reported side effect (n = 19/85, 22.4%). No case of allergic contact dermatitis (ACD) was detected. The popularity of ANMS among young female HCWs is growing. This striking trend might further put these individuals not only at risk of medical device-related adverse events but also occupational ACD.

Assessment of Remineralization Ability of Different Fluoride Varnishes on Artificial Enamel Lesion of Primary Teeth - A Comparative Study.

The current study's aim was to evaluate the potential of various fluoride varnishes to remineralize artificial enamel lesions on primary teeth. For the study, 90 deciduous molar teeth that were implicated for extraction were taken. A window region with a size of 3 × 3 mm was located in the middle of the tooth's coronal surface. The remaining portion was given a coat of nail polish and given time to dry. A demineralizing solution was used to create the artificial enamel lesion. The samples were randomized into three experimental groups at random, with 30 samples in each group. Group 1: Application of Clinpro White Varnish, Group 2: Application of Duraphat Varnish, and Group 3: Application of MI Varnish. After 14 days, samples from each group were examined under scanning electron microscopy at a magnification of 1000× to determine whether remineralization had occurred. Microhardness was also determined using a microhardness tester. Before the intervention, the mean demineralized enamel lesion in the Clinpro White Varnish group was 134.44 ± 0.04, in the Duraphat Varnish group was 133.76 ± 0.12, and in the MI Varnish group was 133.89 ± 0.08. After intervention, the maximum remineralized area was found in the MI Varnish group (82.74 ± 0.18) followed by the Clinpro White Varnish group (101.43 ± 0.16) and the Duraphat Varnish group (104.11 ± 0.10). After the intervention, there was a statistically significant difference found between the groups. After the intervention, the maximum microhardness mean value improved in the MI Varnish group (257.03 ± 1.09 to 261.18 ± 1.20) followed by Clinpro White Varnish (258.78 ± 1.64 to 260.10 ± 1.22) and Duraphat Varnish group (255.24 ± 1.51 to 258.02 ± 0.89). According to the findings of the current investigation, all of the varnishes utilized in this in vitro experiment are capable of correcting early enamel defects on primary teeth. However, MI Varnish group was very effective compared to the Clinpro White Varnish group and the Duraphat Varnish group.

Concealing Meets Healing in the Treatment of Toenail Onychomycosis: A Review of Concurrent Nail Polish Use With Topical Efinaconazole 10% Solution

Introduction: Females are more likely than males to seek help or treatment for onychomycosis and are more likely to camouflage affected nails with nail polish. Between 2016 and 2022, over half of prescriptions for topical efinaconazole 10% solution were written for females, suggesting that there may be particular interest in the interaction between nail polish use concurrent with efinaconazole treatment for onychomycosis.&#x0D; Methods: Review in vitro data on effects of nail polish on nail penetration of efinaconazole 10% solution and clinical studies on the impact of nail polish use on efficacy of topical efinaconazole in the treatment of toenail onychomycosis.&#x0D; Results: Only 4 small studies have assessed interactions between efinaconazole 10% solution and concurrent nail polish use. In vitro, penetration of efinaconazole 10% solution through cadaverous human nails coated with traditional nail polish was similar to penetration through uncoated nails. In a 1-year clinical study, once-daily efinaconazole treatment for 48 weeks was associated with improvements in onychomycosis severity and clear toenail growth that were similar for participants who used traditional nail polish and those who did not use nail polish. In a second, 6-month clinical study, participants received once-daily efinaconazole treatment concurrent with monthly gel nail polish pedicures. After 6 months, 100% of participants tested negative for fungal infection (mycological cure) and all participants experienced visible improvements in their treated toenails. In clinical and in vitro studies, efinaconazole application was associated with degradation of traditional nail polish texture and appearance as well as color transfer to the applicator and unused medication. In contrast, efinaconazole did not affect the duration, quality, or texture of gel nail polish.&#x0D; Conclusions: Application of nail polish did not prevent penetration of efinaconazole 10% solution through human nails or its successful use in the treatment of toenail onychomycosis. Further, efinaconazole did not impact the texture or appearance of gel-polished nails. To our knowledge, these findings represent the only available data on topical treatment of toenail onychomycosis with concurrent nail polish use, and may be of particular importance when selecting treatment options for female patients with onychomycosis.&#x0D; Funding: Ortho Dermatologics

Nail polish used by healthcare personnel does not increase the rate of healthcare-associated infections.

Nail polish used by healthcare personnel does not increase the rate of healthcare-associated infections.

Reusable graphite-based electrochemical sensors for L-dopa and dopamine detection.

Afully reusable electrochemical device is proposed for the first timemade from laser cutting and a homemade conductive ink composed of carbon and nail polish. As a sensor substrate, we applied polymethyl methacrylate, which allows the surface to be renewed by simply removing and reapplying a new layer of ink. In addition to the ease of renewing the sensor's conductive surface, the design of the device has allowed for the integration of different forms of analysis. The determination of L-Dopa was performed using DPV, which presented a linear response range between 5.0 and 1000.0μmol L-1, and a LOD of 0.11μmol L-1. For dopamine, a flow injection analysis system was employed, and using the amperometric technique measurements were performed with a linear ranging from 2.0 to 100.0μmol L-1anda LOD of 0.26μmol L-1. To demonstrate its applicability, the device was used in the quantification of analytes in pharmaceutical drug and synthetic urine samples.

Comparative Evaluation of Longevity of Fluoride Release from Three Different Fluoride Varnishes: An Observational Study.

The cycles of demineralization and remineralization result in a dynamic process of caries development. Caries are prevented by the shift in the balance from demineralization to remineralization at the tooth-oral fluid interface with the help of salivary fluoride levels (in parts per million). The advantages of fluoride varnish application over other substitutes like dentifrices, mouthrinses, gels, or foams are that varnishes are well tolerated by infants, young children, or children with special healthcare needs and have prolonged therapeutic effects. This study was formulated to evaluate and compare the longevity of fluoride release from different fluoride varnishes, namely Fluor Protector, Enamelast, and Enamel Pro varnish. To evaluate and compare the longevity of fluoride release from three different fluoride varnishes. The study samples comprised 72 healthy permanent maxillary anterior teeth. The teeth were divided into four groups, with eighteen teeth in each group. The surfaces of all teeth were then covered by different colored nail varnish according to the respective group, except for a 3 × 3 mm window on the facial (labial) surface of the crown, where the test materials were applied according to their respective group. In group I, Fluor Protector varnish; in group II, Enamelast varnish; and in group III, Enamel Pro varnish was applied. Group IV was the control group; hence, no test material was applied. All specimens were then stored in plastic containers with a pH of 7.2 in artificial saliva at room temperature. The specimens were transferred into new plastic containers after 1 day, containing fresh artificial saliva, and solutions from previous plastic containers were taken for fluoride analysis. This process was repeated sequentially to analyze the amount of fluoride released in ppm from the specimens at the end of 1, 3, and 6 months. Analysis was performed on Statistical Package for the Social Sciences (SPSS) software (Windows version 22.0). Conventionally used 1.5% ammonium fluoride varnish, that is, Fluor Protector varnish, showed the least release of fluoride (0.03 ± 0.0 ppm), while resin carrier-based 5% sodium fluoride varnish, that is, Enamelast varnish showed a good amount of fluoride release for 6 months continuously, that is, (0.16 ± 0.06 ppm) at last follow-up. Enamel Pro varnish, which has 5% sodium fluoride with amorphous calcium phosphate (ACP) formula, was found to be the best varnish as it released the maximum amount of fluoride in ppm in artificial saliva for up to 3 months (0.32 ± 0.08) but less than Enamelast varnish only at 6 months follow-up that is 0.09 ± 0.03 ppm. The present study concludes that based on the amount of fluoride released for 6 months duration, Enamel Pro varnish, followed by Enamelast varnish and Fluor Protector varnish, are advisable to apply for caries prevention. Singh V, Naik S, Vashisth P, et al. Comparative Evaluation of Longevity of Fluoride Release from Three Different Fluoride Varnishes: An Observational Study. Int J Clin Pediatr Dent 2024;17(3):341-345.

In Vitro Analysis of Outcome Differences Between Repairing and Replacing Broken Dental Restorations.

Objective In light of several advancements and considerations in endodontic dentistry, there still remains a need to comprehensively evaluate the outcome disparities between repairing and replacing broken dental restorations. This study aims to compare the effectiveness of repairing dental restorations versus replacing them, focusing on how each method affects the structural strength and longevity of the restorations. Methods The study included 60 freshly removed human maxillary premolars. Initial processing involved rigorous washing, descaling, and polishing of the teeth. To ensure preservation, the specimens were stored in sterile, distilled water. To occlude the root canals, a self-hardening composite resin was used, and the roots were coated with two coats of clear nail polish to prevent moisture penetration. A 245 carbide bur attached to a high-speed dental handpiece with air and water spray cooling produced standardized Class II cavities on the occluso-proximal surfaces. Each cavity had a buccolingual breadth of 2 mm, an occluso-cervical length of 4 mm, and a gingival boundary that was 1 mm coronal to the cement-enamel junction. Following this preparation, the teeth were randomly separated into three groups (Group A, Group B, and Group C), each containing 20 teeth. Results Our analysis showed that teeth with entirely replaced restorations had a higher average fracture resistance than those with repaired restorations. However, the difference in fracture resistance between the repair and replacement groups for each type of material was not statistically significant. Conclusion Based on the findings, repairing a dental restoration can be a conservative and less invasive alternative to a full replacement without a significant compromise in the restoration's ability to withstand fracture. Therefore, dental professionals might consider full restoration as a viable option, taking into account the need to preserve dental tissue as well as the restoration's durability and structural integrity.

In Vitro Evaluation of Remineralization Potential: Whey Extract, Fluoride Varnish, and Fluoride Mouthwash on Bleached Enamel

Background: Extrinsic discoloration is treated with bleaching which increases enamel porosity and roughness. Remineralizing materials is applied to avoid the bleaching side effects. The current study aimed to evaluate time dependent safety of bleaching materials on enamel surfaces roughness, and to assess the remineralizing potential of whey extract as a natural product and to compare it with the commercially available fluoride varnish and fluoride mouthwash after maximum bleaching time (30 min.). Methods: Extracted human incisor teeth without cracks or any enamel defects were used in this study. Teeth were cleaned and decoronated at the level of the cementoenamel junction. A nail varnish was used to cover the entire surface of the crowns of each tooth, leaving a window measuring 4 mm × 4mm. Bleaching material was applied to the enamel of all teeth specimens. The Application of bleaching material was repeated 2 more times, each time for 10 minutes, which amounted in total to 30 min. The specimens in group 1 were soaked in artificial saliva, the specimens in group 2 were soaked in whey extract, the specimens in group 3 were treated with fluoride varnish and group 4 specimens were soaked in fluoride mouthwash. Results: The mean value of the surface roughness of all the teeth specimens was increased significantly after bleaching for 10 minutes, 20 minutes and 30 minutes (p=0.000) when compared with baseline mean value. As well, there was significant direct correlation between application time of bleaching material and mean value of surface roughness (r= 0.94). There were no significant differences (p&gt;0.05) between the specimens of the 4 groups when the mean value of surface roughness compared at baseline and after bleaching. But, after treatment, there was significant difference (p≤0.05) between the 4 groups, with the best result obtained from whey extract and fluoride varnish. Conclusions: The enamel surface roughness is significantly and directly correlated with prolonged application time of bleaching material. Remineralizing materials; whey extract, fluoride varnish and fluoride mouth wash had significantly decreased enamel surface roughness caused by bleaching. Whey extract has statistically the same effect as fluoride varnish on decreasing the surface roughness of bleached enamel surface.

Semi-quantitative health risk assessment of heavy metal dust exposure among nail technicians using the SQRA technique and Monte Carlo simulation.

Nail technology, including the application of artificial nails and nail care, is a developing sector of the global beauty industry. Nail technicians are exposed to a variety of chemical substances through inhalation, as they spend extended periods of time in close proximity to these materials. This study aimed to evaluate the semi-quantitative health risk of dust-containing heavy metals among nail technicians. This analytical descriptive study employed the risk assessment method provided by the Singapore Occupational Health Department to evaluate the health hazards of lead, cadmium, nickel, chromium, and manganese. Dust samples from nail filing were collected from the respiratory zone of 20 nail technicians following the NIOSH 7300 method. The samples were analyzed using ICP-OES instrumentation. Monte Carlo simulation was utilized to characterize the risk and its uncertainties. Manganese and cadmium had the highest and lowest mean concentrations, respectively. The risk scores of the metals ranked from highest to lowest were as follows: . All five metals had risk rankings below 2.8, signifying a minimal risk level. Sensitivity analysis using Spearman's correlation coefficient demonstrated a positive relationship between concentration, daily hours of exposure, and the number of workdays per week with the risk score (RR) and exposure level (ER). Conversely, the variable of weekly working hours (W) showed a negative correlation with these parameters. Despite the low-risk level of the examined metals, continuous exposure and potential long-term effects on nail technicians warrant preventive measures. Recommendations include implementing local exhaust ventilation systems, using table fans, establishing work-rest cycles, wearing N95 dust masks, and using reputable and high-quality nail polishes.

Bond strength comparison of a fiber-reinforced composite resin: Different dentin conditions and preparation techniques.

This study aimed to compare the bond strength of a fiber-reinforced composite resin with traditional and bulk-fill composite resins under different dentin conditions and preparation techniques. Eighty molar teeth, excluding the mesio-distal half of the occlusal dentin surfaces of each teeth, were isolated with acid-resistant nail varnish and stored in a demineralisation solution (pH 4.5). After mechanical removal of the varnish, the teeth were buried in acrylic resin blocks. In every composite resin group, one-half of the specimens were prepared with a diamond bur and another half with Er: YAG laser. Then, the specimens were divided into four groups of composite resins (Filtek Z250, G-aenial Posterior, SonicFill 2, Ever X Posterior) (n = 10). Shear bond strengths were measured using a universal testing device, and failure types were determined with stereomicroscope images. SEM images were obtained at 1000× magnification. Data were analyzed using a three-way analysis of variance (ANOVA), and Bonferroni correction was used for multiple comparisons (p = .05). Differences in the dentin surface affected the bond strength results (p < .05), whereas there was no significant difference between cavity preparation methods (p > .05). EverX Posterior showed the highest bond strength results. Within the limitations of this study, fiber-reinforced composite resin exhibited successful bond strength results in addition to improved mechanical properties. RESEARCH HIGHLIGHTS: Fiber-reinforced composite had successful bond strength values. Bond strength values of sound dentin groups were higher than those of caries-affected dentin groups. The use of an Er: YAG laser for preparation did not lead to insufficient bond strength results.

Inhalation exposure to toxic heavy metals in nail salon technicians and health risk assessment using Monte Carlo simulation

Objective Nail salons offer a developing and diverse occupation for many women, especially the new generation. Due to the increasing apprehension surrounding heavy metals in dust caused by filing nails containing dried nail polish, the present study was designed aimed to health risk assessment of heavy metals in breathing zone of nail salon technicians (NSTs). Methods This is a cross-sectional study that was conducted in NSTs. The concentration of Cadmium (Cd), Lead (Pb), Nickel (Ni), Chromium (Cr) and Manganese (Mn)in breathing zone of 20 NSTs was determined using ICP-OES. Results The metal concentrations were in the following order: Mn > Pb > Ni > Cr > Cd with corresponding arithmetic mean values of0.008, 0.0023, 0.0021, 0.001 and 0.0006 mg m−3, respectively, which are exceeded the recommended levels stated in the indoor air guidelines. The average lifetime carcinogenic risk (LCR) for Cr, Cd, Ni and Pb was calculated 0.0084, 0.00054, 0.00026 and 1.44 E − 05, respectively. The LCR values of all metals (except Pb) exceeded the acceptable level set by the USEPA. The mean of Hazard quotients (HQ) for Mn, Cd, Cr, Ni and Pb were calculated to be23.7, 4.74, 2.19, 0.51 and 0.0.24, respectively. The sensitivity analysis showed that, the exposure frequency (EF) for Cr and Ni had the strong effects on generation of both LCR and HQ. Furthermore, the concentrations of Mn, Cd and Pb had strong impacts on the HQ generation and the concentration of Cd and Pb had main effects on LCR generation. Conclusion To effectively reduce pollutant concentration, it is recommended to install a ventilation system near nail salon work tables and conduct continuous monitoring and quality control of nail products.

Controversias sobre los riesgos procarcinogénicos asociados al uso de lámparas ultravioleta polimerizadoras para el esmaltado permanente de uñas

BackgroundControversy has recently broken out over the potential carcinogenic risk associated with exposure to UV lamps for permanent nail polish. The new LED-based polymerization devices, and their potential biological effect has not been analyzed to this date. ObjectiveTo evaluate the emission power and its potential biological effects on the skin of 2 types of UV LED and fluorescent curing lamps under normal use conditions compared to doses of sunlight exposure. Material and methodsThe emission spectrum (290nm to 450nm) of curing lamps and the Sun at noon on an average summer day in mid-latitude Spain was analyzed. The effective biological irradiance potential for erythema, non-melanoma skin cancer, DNA damage, photoimmunosuppression and permanent pigmentation was also characterized. ResultsThe high-energy UVA-visible irradiance emitted by these devices was similar to the one coming from the Sun in that spectral range while the effective biological doses were lower or similar to those also coming from the Sun. The total UV and high-energy visible dose per manicure session corresponded to that obtained from 3.5min to 6min exposures to the Sun at noon in the summer days at our latitudes. ConclusionsThe exposure times and doses received with the common use of artificial lamp nail drying correspond to sunlight exposures of 3min to 5min in the central hours of the day. This represents a very low carcinogenic potential compared to sunlight exposure, although similar regarding immunosuppressive potential. Photoprotective measures would further minimize the risks.

Evaluating the Sealing Ability of MTA as a Root Canal Sealing Material

This study was to evaluate the potential of using mineral trioxide aggregate (MTA) as a root canal sealing material via comparing its apical sealing ability with that of the most commonly used root canal sealer (Dorifill) zinc oxide based sealer , twenty-eight extracted human single rooted teeth were selected for use in this study . All teeth were prepared in standard manner using hand instruments, randomly divided into two groups of twelve teeth each and a control group of four teeth. Root canals in the two experimental groups were filled laterally condensed gutta percha and either MTA or zinc oxide based (Dorifill) sealer. After sealers had set, the root surfaces were coated with nail varnish except 1 mm at the apex of the root . Positive controls had no root filling and were coated with nail varnish in the same manner, while the negative controls were sealed only entirely with nail varnish. The teeth were immersed into 1% methylene blue dye for 72 hours. The teeth were cleared and the linear extent of dye penetration was measured with a stereomicroscope. Group (MTA) showed significantly less apical dye penetration than group 2 . Positive controls had total leak age and negative controls had no leakage. The study demonstrate that MTA provide an apical seal that is superior to that of zinc o xide based root canal sealer (Dorifill).