Monomer and Bonding Resin Permeation Times Through Stretched Nitrile Gloves

Objectives: To measure permeability of uncured monomers present in a dentin bonding adhesive component through nitrile gloves.
Methods: Four methacrylate monomers identified as present in a commercial dentin bonding adhesive component (Optibond FL, Kerr) (HEMA, TEGDMA, Bis-GMA, GDMA), were tested. Square sections of nitrile gloves (Micro-Touch®, Ansell Healthcare) were cut, and taped to a computer-heated stage (30°C) of a diamond, horizontal attenuated total reflectance unit in an infrared spectrometer, such that the glove was stretched 10%. Small portions of each monomer or adhesive were placed in the center of the square, a sheet of Mylar placed over top, followed by a thin glass plate and a small plastic wafer. Vertical pressure was applied to the layers using 40N-cm torque from a tightening screw. (n=5) Infrared spectra were collected for various time intervals at 2 cm^-1 resolution to obtain a time-based record of the infrared spectrum of the nitrile glove side opposite to which the resins were placed (from 1 to 3 hours). A custom program was written to plot time-based changes in the nitrile glove spectrum where the C=O group (1710-1714 cm^-1), present in all tested materials, indicated permeation of the methacrylate monomer through the glove. The time at which C=O absorption was first detected was recorded. Mean detection times were compared using a 1-way ANOVA and Tukey’s post-hoc test at a pre-set alpha of 0.05.
Results: Table presents results. During 3-hours of scanning, Bis-GMA never permeated the glove. GDMA took the longest time to permeate, and HEMA the least. There was no significant difference in permeation times between TEGDMA and the adhesive component of the commercial dentin bonding agent.
Conclusions: HEMA and TEGDMA were among the fastest methacrylate monomers to permeate the nitrile glove, while the filled, commercial, co-monomer mixture of all tested resins presented longer times.