scholarly journals Dental Composites – a Low-Dose Source of Bisphenol A?

2020 ◽  
pp. S295-S304 ◽  
Author(s):  
M. ŠIMKOVÁ ◽  
A. TICHÝ ◽  
M. DUŠKOVÁ ◽  
P. BRADNA
Keyword(s):  
Bisphenol A ◽  
Low Dose ◽  
Daily Intake ◽  
Dental Composite ◽  
Dental Composites ◽  
Mass Spectrometry Detection ◽  
Endocrine Disrupting ◽  
Liquid Chromatography Tandem Mass ◽  
Dental Restorative ◽  
Kinetics Of

Dental composite materials often contain monomers with bisphenol A (BPA) structure in their molecules, e.g. bisphenol-A glycidyl dimethacrylate (Bis-GMA). In this study, it was examined whether dental restorative composites could be a low-dose source of BPA or alternative bisphenols, which are known to have endocrine-disrupting effects. Bis-GMA-containing composites Charisma Classic (CC) and Filtek Ultimate Universal Restorative (FU) and “BPA-free” Charisma Diamond (CD) and Admira Fusion (AF) were examined. Specimens (diameter 6 mm, height 2 mm, n=5) were light-cured from one side for 20 s and stored at 37 °C in methanol which was periodically changed over 130 days to determine the kinetics of BPA release. BPA concentrations were measured using a dansyl chloride derivatization method with liquid chromatography – tandem mass spectrometry detection. The amounts of BPA were expressed in nanograms per gram of composite (ng/g). BPA release from Bis-GMA-containing CC and FU was significantly higher compared to “BPA-free” CD and AF. The highest 1-day release was detected with FU (15.4±0.8 ng/g), followed by CC (9.1±1.1 ng/g), AF (2.1±1.3 ng/g), and CD (1.6±0.8 ng/g), and the release gradually decreased over the examined period. Detected values were several orders of magnitude below the tolerable daily intake (4 µg/kg body weight/day). Alternative bisphenols were not detected. BPA was released even from “BPA-free” composites, although in significantly lower amounts than from Bis-GMA-containing composites. Despite incubation in methanol, detected amounts of BPA were substantially lower than current limits suggesting that dental composites should not pose a health risk if adequately polymerized.

scholarly journals Long-term solubility and sorption characteristics of novel dental restoratives

2021 ◽  
Vol 13 (1) ◽  
pp. 17-24
Author(s):  
Sukriti Yadav ◽  
Swati Gangwar
Keyword(s):  
Artificial Saliva ◽  
Dental Composite ◽  
Dental Composites ◽  
Distilled Water ◽  
Structural Deterioration ◽  
Dental Restoratives ◽  
Physical And Chemical ◽  
Dental Restorative ◽  
Sorption Characteristics

Sorption and solubility are the unfavorable conditions for the dental restorative composites (DRCs). It can be precursor of various physical and chemical phenomenon that may lead to structural deterioration and minimizes the endurance of restorations. This study sought to evaluate the sorption and solubility features of MPTS (M)/APTES(A) treated n-HAPs filled dental composite in distilled water and artificial saliva medium. In this experiment, 7 different compositions of disc-shaped specimens of Φ15mm×1mm (n=3) of dental composites were prepared and tested under distilled water and artificial saliva medium for 35 days according to ISO 4049 method. The dental material shows relatively higher sorption and solubility in the artificial saliva medium as compared to distilled water. However, at higher wt.% (DRCs-12M & DRCs-12A), it shows minimum solubility (i.e.) and sorption characteristics. The results indicate that there was significant variation regarding storage medium and time to saturation but still these values are within the limit of the ISO 4049 standards, which is 40 μg/mm3 for sorption and 5μg/mm3 for Solubility.

Synthesis and Characteristics of Dental Composites with Novel Bis-GMA Derivate as a Resin Base

2013 ◽  
Vol 745-746 ◽  
pp. 442-446 ◽  
Author(s):  
Rui Li Wang ◽  
Mo Zhu ◽  
Sheng Liu ◽  
Feng Wei Liu ◽  
Xiao Ze Jiang ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Triethylene Glycol ◽  
High Viscosity ◽  
Dental Composites ◽  
Resin Matrix ◽  
Hydroxyl Groups ◽  
Acetyl Group ◽  
Matrix Differential ◽  
Dental Restorative ◽  
Kinetics Of

2,2-bis [4-(2-hydroxy-3-methacryloyloxypropoxy) pheny propane (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) have been commonly used as a viscous monomer and a reactive diluent in the organic phase of dental restorative composites, respectively. The purpose of addition of TEGDMA is mainly to decrease the high viscosity of Bis-GMA caused by hydrogen bonding between hydroxyl groups. However, some adverse effects will accompany with increased amounts of the TEGDMA, such as higher values of polymerization shrinkage, which is not undesirable for the clinical application. Therefore, substituting hydroxyl groups of Bis-GMA might be an appropriate and effective way to reduce the amount of diluents and weaken the accompanied adverse effects. This work focuses on the synthesis of a novel Bis-GMA derivate, substituting acetyl groups for hydroxyl groups in Bis-GMA. The viscosity of Bis-GMA characterized with rotational rheometer was significantly decreased from 820 Pa.s to 11 Pa.s by substitution of acetyl group, leading to the low amount of TEGDMA in resin matrix. Differential Scanning Calorimeter (DSC) was used for investigating the reaction kinetics of this novel monomer with different mass ratios of TEGDMA. The results suggested that the maximum conversion of the Ac-Bis-GMA can reach 88% while the corresponding value for Bis-GMA is 75%. Dental composites were prepared from 2,2-bis [4-(2-acetyl-3-methacryloyloxypropoxy) pheny propane (Ac-Bis-GMA) or Bis-GMA resin mixtures with TEGDMA filled with 70 wt% silica co-fillers. The results presented that dental composites prepared from new resin matrixes exhibited adequate mechanical properties.

scholarly journals Development of an Innovative Urease-Aided Self-Healing Dental Composite

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 84
Author(s):  
Mostafa Seifan ◽  
Zahra Sarabadani ◽  
Aydin Berenjian
Keyword(s):  
Healing Process ◽  
Optical Microscope ◽  
Dental Restoration ◽  
Dental Composite ◽  
Dental Composites ◽  
Resin Matrix ◽  
Self Healing ◽  
Urease Enzyme ◽  
Near Future ◽  
Dental Restorative

Dental restorative materials suffer from major drawbacks, namely fracture and shrinkage, which result in failure and require restoration and replacement. There are different methods to address these issues, such as increasing the filler load or changing the resin matrix of the composite. In the present work, we introduce a new viable process to heal the generated cracks with the aid of urease enzyme. In this system, urease breaks down the salivary urea which later binds with calcium to form calcium carbonate (CaCO3). The formation of insoluble CaCO3 fills any resultant fracture or shrinkage from the dental composure hardening step. The healing process and the formation of CaCO3 within dental composites were successfully confirmed by optical microscope, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDS) methods. This research demonstrates a new protocol to increase the service life of dental restoration composites in the near future.

scholarly journals Bisphenol A Release from Dental Composites and Resin-Modified Glass Ionomers under Two Polymerization Conditions

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 46
Author(s):  
Antonin Tichy ◽  
Marketa Simkova ◽  
Radka Vrbova ◽  
Adela Roubickova ◽  
Michaela Duskova ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Artificial Saliva ◽  
Daily Intake ◽  
Dental Resin ◽  
Case Scenario ◽  
Worst Case ◽  
Initial Release ◽  
Liquid Chromatography Tandem Mass ◽  
Polymerization Conditions

Bisphenol A (BPA)-based monomers are commonly contained in dental resin-based materials. As BPA is an endocrine disruptor, its long-term release from restorative composites and resin-modified glass ionomers (RM-GICs) under two polymerization conditions was measured in this study. Specimens of two conventional composites containing BPA-based monomers, two “BPA-free” composites, and two RM-GICs were polymerized from one side for 20 s at 1300 mW/cm2 or for 5 s at 3000 mW/cm2. The amounts of BPA released in artificial saliva and methanol after 1, 4, 9, 16, 35, 65, 130, and 260 days were measured using liquid chromatography–tandem mass spectrometry. The highest amounts of BPA were released from conventional composites, followed by RM-GICs, while the least was released from “BPA-free” composites. Amounts of released BPA were significantly higher in methanol and decreased gradually after the first day. Fast polymerization (5 s at 3000 mW/cm2) resulted in a significantly higher release of BPA after 1 day, but the effect of polymerization conditions was not significant overall. In conclusion, fast polymerization increased the initial release of BPA, but the released amounts were significantly lower than the current tolerable daily intake (4 μg/kg body weight/day) even in methanol, representing the worst-case scenario of BPA release.

scholarly journals A Systematic Review of Exposure to Bisphenol A from Dental Treatment

2019 ◽  
Vol 4 (2) ◽  
pp. 106-115 ◽  
Author(s):  
T. Marzouk ◽  
S. Sathyanarayana ◽  
A.S. Kim ◽  
A.L. Seminario ◽  
C.M. McKinney
Keyword(s):  
Systematic Review ◽  
Bisphenol A ◽  
Dental Treatment ◽  
Dental Materials ◽  
Library Science ◽  
Dental Composite ◽  
Endocrine Disrupting Chemical ◽  
Endocrine Disrupting ◽  
Before And After ◽  
Open Question

Introduction: Dental composite restorations and dental sealants containing bisphenol A glycidyl methacrylate (BisGMA) are commonly used materials in dentistry. Bisphenol A (BPA) is used to manufacture BisGMA and can be a by-product in BisGMA-based dental materials. BPA is an endocrine-disrupting chemical that may affect reproductive, psychological, cognitive, and endocrine-related health. We conducted a systematic review of clinical studies that measured urinary BPA (uBPA) concentrations before and after dental treatment to evaluate the extent to which individuals are exposed to BPA from dental treatment. Methods: Eligibility included studies that measured uBPA concentrations before and after dental treatment with any type of resin-based dental material. We searched PubMed, Cochrane, Web of Science, Virtual Health Library, Science Direct, ProQuest, and Clinical Trials with no date or language restrictions to identify published studies. We summarized eligible studies across participant characteristics, amount of treatment, and time of follow-up measures. Because methods of measuring uBPA varied, our primary outcome was the direction and percentage change between baseline and 24 h posttreatment and at later time points as available. Results: We identified 1,190 abstracts and 7 eligible studies: 4 in children and 3 in adults. In all studies, BPA concentrations increased 24 h after treatment. The 2 studies with the largest sample sizes found statistically significant increases >40% in uBPA concentrations at 24 h posttreatment (both P values <0.01). The 1 study to examine uBPA concentrations beyond 1 mo posttreatment found that concentrations returned to baseline by 14 d after treatment and remained at baseline 6 mo after treatment. Conclusions: Our findings suggest that uBPA concentrations increase 24 h after dental treatment. One study showed that uBPA concentrations return to baseline by 14 d. Additional research is needed to determine the magnitude of change from pre– to post–dental treatment and the trajectory of uBPA concentrations posttreatment. Knowledge Transfer Statement: BPA is an endocrine-disrupting chemical that may have negative human health effects. Our findings suggest that urinary BPA concentrations increase in the short term after dental treatment. The extent to which such an increase may affect the health of patients remains an open question, particularly since there are no established thresholds for safety or harm related to BPA exposure.

scholarly journals Bisphenol A and Its Analogues in Chinese Total Diets: Contaminated Levels and Risk Assessment

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Kai Yao ◽  
Jing Zhang ◽  
Jie Yin ◽  
Yunfeng Zhao ◽  
Jianzhong Shen ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Food Packaging ◽  
Endocrine Disrupting Chemicals ◽  
Daily Intake ◽  
Dietary Exposure ◽  
Food Samples ◽  
Dietary Intakes ◽  
Bisphenol S ◽  
Endocrine Disrupting ◽  
Exposure Levels

Bisphenol A (BPA) and its analogues (BPs) are suspected posing potential endocrine disrupting properties. They might migrate into foodstuffs through food packaging materials or contaminated water and soil. Dietary exposure is of paramount importance way for human health. European Food Safety Authority (EFSA) lowered the value of tolerable daily intake (TDI) from 50 μg/kg bw/day (d) to a temporary (t) TDI (t-TDI) of 4 μg/kg bw/d. In this study, the Chinese total dietary samples were analyzed for assessing the exposure risk of BPs by diets. BPA, bisphenol F (BPF), bisphenol S (BPS), and bisphenol AF (BPAF) were found in 12 kinds of food samples except for bisphenol B (BPB). A deterministic approach was used to calculate the dietary intakes of 4 kinds of compounds. For different age and gender groups, the exposure levels of BPA (178.440-403.672 ng/kg bw/d) was the highest, followed by BPS (21.372-52.112 ng/kg bw/d), BPF (20.641-50.507 ng/kg bw/d), and BPAF (0.434-1.210 ng/kg bw/d). Based on the t-TDI set by EFSA (4 μg/kg bw/d for BPA), the BPs through dietary intake pose low risks on the Chinese general population even summarization exposure levels of different BPs. However, human can be exposed to multiple endocrine disrupting chemicals rather than BPs alone; combined exposure risks should be further considered.

scholarly journals Low-dose effects of bisphenol A on early sexual development in male and female rats

Reproduction ◽  
2014 ◽  
Vol 147 (4) ◽  
pp. 477-487 ◽  
Author(s):  
Sofie Christiansen ◽  
Marta Axelstad ◽  
Julie Boberg ◽  
Anne Marie Vinggaard ◽  
Gitte Alsing Pedersen ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Sexual Development ◽  
Low Dose ◽  
Dose Range ◽  
Daily Intake ◽  
Reproductive Organ ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats ◽  
Pregnancy And Lactation

Bisphenol A (BPA) is widely detected in human urine and blood. BPA has been reported to impair many endpoints for reproductive and neurological development; however, it is controversial whether BPA has effects in the microgram per kilogram dose range. The aim of the current study was to examine the influence of BPA on early sexual development in male and female rats at dose levels covering both regulatory no observed adverse effect levels (NOAELs) (5 and 50 mg/kg bw per day) as well as doses in the microgram per kilogram dose range (0.025 and 0.25 mg/kg bw per day). Time-mated Wistar rats (n=22) were gavaged during pregnancy and lactation from gestation day 7 to pup day 22 with 0, 0.025, 0.25, 5 or 50 mg/kg bw per day BPA. From 0.250 mg/kg and above, male anogenital distance (AGD) was significantly decreased, whereas decreased female AGD was seen from 0.025 mg/kg bw per day and above. Moreover, the incidence of nipple retention in males appeared to increase dose relatedly and the increase was statistically significant at 50 mg/kg per day. No significant changes in reproductive organ weights in the 16-day-old males and females and no signs of maternal toxicity were seen. The decreased AGD at birth in both sexes indicates effects on prenatal sexual development and provides new evidence of low-dose adverse effects of BPA in rats in the microgram per kilogram dose range. The NOAEL in this study is clearly below 5 mg/kg for BPA, which is used as the basis for establishment of the current tolerable daily intake (TDI) by EFSA; thus a reconsideration of the current TDI of BPA appears warranted.

scholarly journals Release of Bisphenol A from Milled and 3D-Printed Dental Polycarbonate Materials

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5868
Author(s):  
Antonin Tichy ◽  
Marketa Simkova ◽  
Josef Schweiger ◽  
Pavel Bradna ◽  
Jan-Frederik Güth
Keyword(s):  
Bisphenol A ◽  
Endocrine Disruptor ◽  
Artificial Saliva ◽  
Daily Intake ◽  
Tandem Mass ◽  
Case Scenario ◽  
Worst Case ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
3D Printed

Polycarbonates are polymers of bisphenol A (BPA), a well-known endocrine disruptor. This study evaluated the release of BPA from polycarbonate crowns that were (1) milled from Temp Premium Flexible (ZPF, Zirkonzahn, Italy) or Tizian Blank Polycarbonate (TBP, Schütz Dental, Germany), or (2) 3D-printed (Makrolon 2805, Covestro, Germany). Commercial prefabricated polycarbonate crowns (3M, USA) and milled poly(methyl methacrylate) (PMMA) crowns (Temp Basic, Zirkonzahn, Italy) were included for comparison. The crowns were stored at 37 °C in artificial saliva (AS) or methanol, which represented the worst-case scenario of BPA release. Extracts were collected after 1 day, 1 week, 1 month and 3 months. BPA concentrations were measured using liquid chromatography-tandem mass spectrometry. The amounts of released BPA were expressed in micrograms per gram of material (μg/g). After 1 day, the highest amounts of BPA were measured from milled polycarbonates, TBP (methanol: 32.2 ± 3.8 mg/g, AS: 7.1 ± 0.9 mg/g) and ZPF (methanol 22.8 ± 7.7 mg/g, AS: 0.3 ± 0.03 mg/g), followed by 3D-printed crowns (methanol: 11.1 ± 2.3 mg/g, AS: 0.1 ± 0.1 mg/g) and prefabricated crowns (methanol: 8.0 ± 1.6 mg/g, AS: 0.07 ± 0.02 mg/g). Between 1 week and 3 months, the average daily release of BPA in methanol and AS decreased below 2 mg/g and 0.6 mg/g, respectively. No BPA was released from PMMA in AS, and the cumulative amount released in methanol was 0.2 ± 0.06 mg/g. In conclusion, polycarbonates could be a relevant source of BPA, but the current tolerable daily intake of BPA (4 mg/kg body weight) should not be exceeded.

scholarly journals An investigation into bisphenol-A leaching from orthodontic materials

2013 ◽  
Vol 84 (3) ◽  
pp. 516-520 ◽  
Author(s):  
Matthew W. Kotyk ◽  
William A. Wiltshire
Keyword(s):  
Bisphenol A ◽  
Low Dose ◽  
Artificial Saliva ◽  
Daily Intake ◽  
Temperature Cycling ◽  
Medical Disorders ◽  
Dose Effects ◽  
Orthodontic Materials ◽  
Gas Chromatography Mass Spectroscopy ◽  
Low Dose Effects

ABSTRACT Objective: To quantitatively determine the bisphenol-A (BPA) leached from orthodontic materials during simulated intraoral exposure. Materials and Methods: Samples of orthodontic materials were subjected to simulated abrasion, immersion in artificial saliva, thermal shock via temperature cycling, and simulated intraoral exposure. Sample aliquots were collected for up to 2 weeks after artificial saliva immersion, derivatized, then analyzed for BPA by gas chromatography/mass spectroscopy. Results: Quantifiable amounts of leached BPA were observed from a thermoformed orthodontic retainer material (7.63 µg/g of material) and an orthodontic adhesive (2.75 µg/g of material). BPA leaching was only observed within the first 3 days of artificial saliva immersion. Conclusions: Under the test conditions, BPA was observed to leach from two orthodontic materials. While the quantities of leached BPA were below the reference dose for daily intake, existing data of low-dose effects and medical disorders associated with elevated urinary BPA levels suggest that BPA exposure, and thus the use of the leaching materials identified in this study, should be reduced or eliminated.

Light-cured dental composites characterization by Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 428-429
Author(s):  
B. M. Culbertson ◽  
M. L. Devinev ◽  
E. C. Kao
Keyword(s):  
Electron Microscopy ◽  
Mechanical Analysis ◽  
Service Performance ◽  
Dental Composite ◽  
Dental Composites ◽  
Neat Resin ◽  
Scanning Calorimetry ◽  
Research Meeting ◽  
Formulation Variables

The service performance of current dental composite materials, such as anterior and posterior restoratives and/or veneer cements, needs to be improved. As part of a comprehensive effort to find ways to improve such materials, we have launched a broad spectrum study of the physicochemical and mechanical properties of photopolymerizable or visible light cured (VLC) dental composites. The commercially available VLC materials being studied are shown in Table 1. A generic or neat resin VLC system is also being characterized by SEM and TEM, to more fully understand formulation variables and their effects on properties.At a recent dental research meeting, we reported on the differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) characterization of the materials in Table 1. It was shown by DSC and DMA that the materials are substantially undercured by commonly used VLC techniques. Post curing in an oral cavity or a dry environment at 37 to 50°C for 7 or more hours substantially enhances the cure of the materials.

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