Evaluation of Monomer Leaching from Resin Cement Through Dentin

European Journal of Prosthodontics and Restorative Dentistry (2019) 27, 10–17

The aim of the study was to evaluate the elution of Triethylene glycol dimethacrylate (TEGDMA), Urethane dimethacrylate (UDMA), Bisphenol A glycerolate dimethacrylate (BisGMA), and Bisphenol A (BPA), from a dual -cured resin cement through human dentin, under constant positive pulpal pressure. Ten human dentin disks were adjusted into a custom made testing device and transparent glass slabs were luted with Variolink II cement, under a steady pressure. The device was filled with Ringer’s solution and a pressure of 14.1 cm H2O was applied. Eluates were retrieved from each one of the ten specimens at 9 time intervals. All the samples were analyzed by High Performance Liquid Chromatography (HPLC). TEGDMA was detected from the second and UDMA was detected from the fourth time interval. The highest average concentration of TEGDMA and UDMA was detected in the 3 day time interval. Time had a significant effect on their elution. BPA and BisGMA were not detected in any sample at any time interval. The clinical relevance of the present study is that the concentration of the eluted monomers, under the conditions that were chosen, did not reach toxic levels for the pulp.

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Bisphenol A (BPA) Bisphenol A Glycerolate Dimethacrylate (BisGMA) Dentin Permeability Triethylene Glycol Dimethacrylate (TEGDMA) Urethane Dimethacrylate (UDMA)

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Dr. Christina Kerezoudi *
(Dentist, PhD, Msc)

Dr. Victoria F. Samanidou *

(Professor of Analytical Chemistry)

Dr. Christos Gogos *

(Assistant Professor of Endodontics)

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(Professor of Endodontics) (Professor of Basic Dental Sciences)

Address for Correspondence

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Dr. Christina Kerezoudi

In vivo radioactive tracer experiments have demonstrated that radioactive compounds can move either direction across dentin: from the systemic circulation to dentin and vice versa,1,2 so dentin is considered as “a permeable barrier”.3 The thousands of dentinal tubules that transverse the dentin allow ions, fluids, minute particles and bacteria to penetrate through dentin.3,4 Dentin’s permeability varies, even in different areas of the same tooth section and this phenomenon has been attributed to distinct differences in the structure of dentin, from area to area.5 So, factors like the age of the tooth, the presence or the absence of the smear layer, the proximity of the dental material to the pulp, and also the diameter, the density and the length of the dentinal tubules have an effect on dentin’s permeability. The area of dentin in close contact with a dental material is a significant factor that it should be considered in permeability studies and in reality, the area of dentin which is available for diffusion is defined by the diameter, the density and the length of the dentinal tubules.3,4 On the other hand, some compounds penetrate through dentin more easily than others. The easiness of a compound to travel across dentin depends upon several factors like the molecular size, the charge, the hydrophobic or hydrophilic nature, the chemical affinity of the compound with the dentin, the diffusion coefficient and the applied concentration of the compound.3,6 Over more, the outward movement of the dentinal tubule fluid has a competitive action against the passage of the compounds.7,8 Reduced percentages of several compounds were detected when a positive pulpal pressure was applied.9,10 Thus, the positive pulpal pressure is a factor that should be considered in in vitro permeability studies. In human teeth, the positive pulpal pressure has been estimated at about 14.1 cm H2O.11

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Dr. Dimitrios Tziafas *

Dr. Georgios Palaghias *

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Evaluation of Monomer Leaching from a Resin Cement Through Dentin

Email: kerezoudi@yahoo.com

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* Aristotle University of Thessaloniki

Received: 23.08.18 Accepted: 21.01.19

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