adam, Author at IAOMT Library

Modulators of mercury risk to wildlife and humans in the context of rapid global change.

Environmental mercury (Hg) contamination is an urgent global health threat. The complexity of Hg in the environment can hinder accurate determination of ecological and human health risks, particularly within the context of the rapid global changes that are altering many ecological processes, socioeconomic patterns, and other factors like infectious disease incidence, which can affect Hg exposures and health outcomes. However, the success of global Hg-reduction efforts depends on accurate assessments of their effectiveness in reducing health risks. In this paper, we examine the role that key extrinsic and intrinsic drivers play on several aspects of Hg risk to humans and organisms in the environment. We do so within three key domains of ecological and human health risk. First, we examine how extrinsic global change drivers influence pathways of Hg bioaccumulation and biomagnification through food webs. Next, we describe how extrinsic socioeconomic drivers at a global scale, and intrinsic individual-level drivers, influence human Hg exposure. Finally, we address how the adverse health effects of Hg in humans and wildlife are modulated by a range of extrinsic and intrinsic drivers within the context of rapid global change. Incorporating components of these three domains into research and monitoring will facilitate a more holistic understanding of how ecological and societal drivers interact to influence Hg health risks.

By Eagles-Smith CA, Silbergeld EK, Basu N, Bustamante P, Diaz-Barriga F, Hopkins WA, Kidd KA, Nyland JF.|2018-08-06T22:18:04+00:00January 1st, 2018|Mercury|

Ex vivo mercury release from dental amalgam after 7.0-T and 1.5-T MRI.

Purpose:

To evaluate ex vivo mercury release from dental amalgam after 7.0-T and 1.5-T MRI.

Materials and Methods:

The authors evaluated 60 caries-free molar or premolar teeth that had been extracted for clinical indications. Two-sided cavities were opened in each tooth and amalgam fillings applied. After 9 days, two groups of 20 randomly selected teeth were placed in 20 mL of artificial saliva immediately followed by 20 minutes of MRI exposure at 1.5 or 7.0 T. A control group of teeth was placed in artificial saliva without undergoing MRI exposure. The teeth were removed from the artificial saliva 24 hours later, and the saliva was analyzed for mercury content by using inductively coupled plasma mass spectrometry. One-way analysis of variance was used to compare the mean mercury values among the three independent groups, and the Tukey test was used for multiple comparisons of the mean values.

Results:

The mean mercury content of the artificial saliva was 673 μg/L ± 179 in the 7.0-T MRI group, 172 μg/L ± 60 in the 1.5-T MRI group, and 141 μg/L ± 152 in the control group. The mercury content in the 7.0-T group was greater than that in both the 1.5-T group (P < .001; 95% confidence interval: 368 μg/L, 633 μg/L) and the control group (P < .001; 95% confidence interval: 416 μg/L, 648 μg/L). There was no statistically significant difference in mercury content between the 1.5-T and control groups (P = .84; 95% confidence interval: -164 μg/L, 110 μg/L).

Conclusion:

In an ex vivo setting, mercury was released from amalgam fillings after exposure to 7.0-T MRI but not 1.5-T MRI.

By Yilmaz S, Adisen MZ.|2018-08-13T21:37:47+00:00January 1st, 2018|Mercury|

What factors affect the severity of permanent tooth impaction?

BACKGROUND:
The aim of this study was to investigate the association between the severity of permanent tooth impaction and a number of predefined factors, including tooth type, age, gender, tooth agenesis, microdontia of maxillary lateral incisor, and retained deciduous predecessors.

METHODS:
A sample of 2979 dental patients, aged 15 to 40 years, was surveyed by two calibrated examiners for permanent tooth impaction (excluding third molars). On panoramic radiographs, the impacted teeth were initially ranked based on their vertical, horizontal, and angular positions, and the ranking was then analysed for distribution by the predefined factors. To test the age factor, patients were divided into younger (15 to 25 yr) and older (between 25 and 40 yr) age groups. The statistical significance of the ranked vertical, horizontal, and angular positions of impacted teeth by the investigated factors was determined using the Wilcoxon-Mann-Whitney U test.

RESULTS:
The angular position of the impacted teeth was more severe in the older age group (P = 0.012) and in females (P = 0.018). The maxillary canine had more severe horizontal (P = 0.001) and angular (P = 0.003) impactions in females. Tooth agenesis was associated with less severe horizontal impaction (P = 0.041) in the mandibular second premolar. In addition, microdontia of the maxillary lateral incisor was associated with more severe horizontal impaction in general, and more severe horizontal (P = 0.024) and angular (P = 0.010) impaction of the mandibular second premolar in particular. Finally, our results showed that a retained deciduous predecessor was linked to a less severe vertical impaction of the mandibular second premolar (P = 0.030) and horizontal impaction of the maxillary second premolar (P = 0.037) but more severe angular impaction of the mandibular canine.

CONCLUSIONS:
This study suggests that the more delayed the treatment, being a female, the presence of maxillary lateral incisor with microdontia, and retained lower deciduous canines might be associated with more severe position of the impacted teeth. Because the severity of tooth impaction would follow different patterns when considering the investigated factors, it is mandatory to include such factors during dental diagnoses and the planning of preventive or interceptive interventions for young patients.

By Al-Abdallah M, AlHadidi A, Hammad M, Dar-Odeh N.|2019-02-18T21:27:36+00:00January 1st, 2018|Other|

Association of methylmercury intake from seafood consumption and blood mercury level among the Asian and Non-Asian populations in the United States.

METHODS:
We estimated ADMI from seafood using the 30-day fish consumption data from the NHANES 2011-2014 datasets. Using multivariable linear regression, we estimated the proportional change in mean BMeHg associated with a doubling of the ADMI. Further, correlations between ADMI and BMeHg were compared between Asians and other racial/ethnic groups.

RESULTS:
Our analysis found both Asian WORA and Asian adults age ≥ 50 years old had significantly higher BMeHg levels and ADMI than their Non-Asian counterparts. Correlations between ADMI from seafood and blood Hg levels were stronger among Asian WORA than among Non-Asian WORA. Key fish species that influenced the dietary MeHg intake for Asians were mackerel, tuna, and “other known/unknown fish species”.

CONCLUSION:
We confirmed that Asian populations have higher MeHg intake than the Non-Asian population in the U.S. and seafood intake is a key predictor of blood Hg concentration, especially among Asian women of reproductive age. Future studies should incorporate information on other known and unknown fish species that are frequently consumed by Asian populations and different parts and fish organs eaten to better understand determinants of MeHg exposure.

By Liu Y, Buchanan S, Anderson HA, Xiao Z, Persky V, Turyk ME.|2018-08-09T21:25:31+00:00January 1st, 2018|Mercury|

Debris Removal from the Mesial Root Canal System of Mandibular Molars with Laser-activated Irrigation.

INTRODUCTION:

The purpose of this study was to compare in vitro the canal and isthmus debridement of manual-dynamic, passive ultrasonic, and laser-activated irrigation with an Er:YAG laser in mesial roots of human mandibular molars.

METHODS:

Fifty extracted mandibular molars with an isthmus were embedded in resin and sectioned axially 4 mm from the apex. The teeth were reassembled with guide pins and bolts, and the mesial canals were instrumented up to a ProTaper F2 rotary file (Dentsply Maillefer, Ballaigues, Switzerland). Teeth were randomly assigned to the following irrigant activation groups (n = 10): conventional needle irrigation (NI), manual-dynamic irrigation with a ProTaper F2 gutta-percha cone, ultrasonically activated irrigation using a size 20 Irrisafe (Satelec Acteon, Mérignac, France), and laser-activated irrigation (LAI) with an Er:YAG laser and a conical 400-μm fiber tip in the canal entrance or a 600-μm tip over the canal entrance. Root cross-sectional images were taken before and after final irrigation, and the area occupied by debris in the main canal and the isthmus was determined using image analysis software. Differences in debris before and after activation were statistically compared within and across groups.

RESULTS:

Significant reductions in debris levels were observed in all groups, except for NI and manual-dynamic irrigation (canal only). None of the methods rendered the canal systems debris free. In the canal, LAI with an Er:YAG laser and a 600-μm tip over the canal entrance removed significantly more debris than NI. In the isthmus, LAI with an Er:YAG laser and a conical 400-μm fiber tip in the canal entrance removed significantly more debris than NI.

CONCLUSIONS:

Within the limitations of this in vitro study, canal and isthmus cleanliness significantly improved after irrigant activation.

By Passalidou S, Calberson F, De Bruyne M, De Moor R, Meire MA.|2019-05-24T21:15:35+00:00January 1st, 2018|Other|

Cutaneous abscess as a complication of bisphosphonate-related osteonecrosis of the jaw.

Dear Editor:

In clinical dermatology, abscesses are generally caused by secondary impetiginization of a previous furuncle or a ruptured epidermal cyst. We encountered a rare case of cutaneous abscess in the maxillo-mandibular region, complicated by bisphosphonate-related osteonecrosis of the jaw.

By Yang MY, Jin H, You HS, Shim WH, Kim JM, Kim GW, Kim HS, Ko HC, Kim MB, Kim BS.|2018-08-13T21:13:07+00:00January 1st, 2018|Other|

Healing of Oral Lichenoid Lesions following Replacement of Dental Amalgam Restorations with Feldspathic Ceramic Inlay-Onlay Restorations: Clinical Results of a Follow-Up Period Varied from Three Months up to Five Years.

Objective:
Previous studies have shown the effect of amalgam removal on the healing of oral lichenoid lesions (OLLs); however, no specific replacement materials have been suggested. The present series evaluated long-term results following the complete replacement of amalgam restorations with feldspathic ceramic inlay-onlay restorations for a group of patients with OLLs whose lesions were suspected to be related to amalgam restorations.

Materials and Methods:
Twenty-four patients who had OLLs suspected to be related to their amalgam restorations were initially recruited. The patients underwent patch tests for a series of dental materials, in addition to clinical and histopathological examination. Sixteen (67%) of the 24 patients had their amalgam replaced with feldspathic ceramic inlay-onlay restorations and were examined within a follow-up period of 3 months to 5 years.

Results:
After 3 months of clinical follow-up, complete healing (63%) was noted in all patients with OLLs whose lesions were in only close contact with their amalgam restorations. Healing was significantly related to the combination of lesions with close contact with the amalgam restoration and a diagnosis of OLL (x2 test, P=0.02).

Conclusion:
Feldspathic ceramic can be safely used as a replacement material for patients with OLLs to diminish adverse reactions to amalgam restorations.

By Karatasli B, Karatasli G, Mete O, Erdem MA, Cankaya AB.|2019-02-18T21:06:38+00:00January 1st, 2018|Mercury|

Qualitative analysis of dental material ingredients, composite resins and sealants using liquid chromatography coupled to quadrupole time of flight mass spectrometry.

Since 2011, the World Health Organization has encouraged a global phase-down of the use of dental amalgam and actively supported the use of alternative, resin-based dental materials. The resins consist of (meth)acrylate monomers derived from Bisphenol A (BPA), such as Bisphenol A glycidyl methacrylate (BisGMA) and Bisphenol A ethoxylate methacrylate (BisEMA) or triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA) which lack the BPA backbone. Besides monomers, other compounds such as photoinitiators and stabilizing agents can be present in the dental resin matrices. The current study consists in the development of an analytical method for the separation and identification of dental material components using LC-QTOF-MS. The developed method was applied on several dental material ingredients, unpolymerized composite resins, and a common dental sealant. The acquired high resolution accurate-mass data was analyzed using suspect screening with an in-house developed library. Next to the main components, various isomers and impurities related to the production of the main component have been detected and identified in the dental material ingredients. In total, 39 chemicals have been identified in the analyzed dental materials. On average 15 chemicals have been identified. Major components, such as BisEMA, BisGMA and TEGDMA were identified although they were not always stated in the material safety data sheets. Minor components included photoinitiators, such as ethyl 4-dimethyl aminobenzoate (EDMAB) and (meth)acrylates impurities originating from production of main ingredients.

By Vervliet P, de Nys S, Boonen I, Duca RC, Elskens M, van Landuyt KL, Covaci A.|2019-01-06T20:59:43+00:00January 1st, 2018|Other|

Use of the flu vaccine opens the door to studying associations between inflammation, depression, and cognitive impairments.

The current paper published in Brain, Behavior, and Immunity by Kuhlman and colleagues demonstrate that even mild inflammatory responses following vaccination with the influenza vaccine are sufficient to induce depressed mood and cognitive impairments in healthy young adults (Kuhlman et al., 2018). The authors found that following vaccination participants demonstrated changes of varying magnitude in serum IL-6 levels measured pre- and 1 day post-vaccination, and that larger increases in circulating IL-6 were associated with greater mood disturbances and cognitive symptoms. Changes in mood and cognitive function were measured the week prior to and the week after vaccination by the analysis of daily diaries that consisted of the 15-item Profile of Mood States (POMS-15) and 3-item POMS-Confusion subscale (inability to concentrate, forgetfulness, and confusion).

By Johnson JD.|2018-08-08T20:50:34+00:00January 1st, 2018|Other|

Five hundred patients reporting on adverse effects from dental materials: Frequencies, complaints, symptoms, allergies.

OBJECTIVE:
Information on patients with real or claimed adverse reactions towards dental materials in large patient cohorts is rare. Therefore, the aim of the present study was to investigate patients reporting on complaints and symptoms to dental materials over a 16-year period.

METHODS:
Five hundred patients were characterized by one single dental team regarding age and sex distribution, subjective complaints and objective intraoral symptoms, and allergy status relevant to dental materials.

RESULTS:
Elder patients and females predominated. Subjective complaints were reported by 490 patients, ranging from 1 to 12 complaints per patient. Most often, burning mouth (44%), tooth-/jawache (22%) and dry mouth (20%) were reported. In 54% no objective intraoral symptom was diagnosed. The main objective intraoral symptoms were tongue anomalies (lingua plicata or geographica; 14%), gingivitis adjacent to restorations (12%), redness of the palate or the edentulous ridge (7%), oral lichen planus (6%), grayish discolorations, lichenoid contact lesions, and leukoplakia (<5%). Patch testing of 416 (83%) patients revealed that allergy was diagnosed as contributing to the complaints or symptoms in 70 (14%) patients with metals being the most frequent allergens. Gingivitis adjacent to restorations (3.2%), redness of the palate or edentulous ridge (1.4%) and whitish lichen-like lesions (1.8%) were associated to allergy from dental materials.

SIGNIFICANCE:
The high number of subjective complaints per patient and their wide variety suggests that most patients seriously suffered. Furthermore, the fact that only 46% of the patients had objective intraoral symptoms demands for an interdisciplinary collaboration to elucidate other than dental causes.

By Mittermüller P, Hiller KA, Schmalz G, Buchalla W|2019-01-06T20:50:49+00:00January 1st, 2018|Periodontal Disease|

adam

About Eagles-Smith CA, Silbergeld EK, Basu N, Bustamante P, Diaz-Barriga F, Hopkins WA, Kidd KA, Nyland JF.