Water distribution in dentin matrices: Bound vs. unbound water. Issue 3 (March 2015)

• Record Type: Journal Article
• Authors: Agee, Kelli A.; Prakki, Anuradha; Abu-Haimed, Tariq; Naguib, Ghada H.; Nawareg, Manar Abu; Tezvergil-Mutluay, Arzu; Scheffel, Debora L.S.; Chen, Chen; Jang, Seung Soon; Hwang, Hyea; Brackett, Martha; Grégoire, Geneviéve; Tay, Franklin R.; Breschi, Lorenzo; Pashley, David H.
• Is Part Of: Dental materials. Volume 31:Issue 3(2015)
• Page Start: 205
• Page End: 216
• Publication Date: 2015-03
• Subjects: Dentistry -- Periodicals; Dental materials -- Periodicals; 617.695
• DOI: 10.1016/j.dental.2014.12.007
• Languages: English
• ISSNs: 0109-5641

Abstract

<abstract abstract-type="author" id="abs0005"> <title id="sect0005">Abstract</title> <sec> <title id="sect0010">Objective</title> <p id="spar0005">This work measured the amount of bound versus unbound water in completely-demineralized dentin.</p> </sec> <sec> <title id="sect0015">Methods</title> <p id="spar0010">Dentin beams prepared from extracted human teeth were completely demineralized, rinsed and dried to constant mass. They were rehydrated in 41% relative humidity (RH), while gravimetrically measuring their mass increase until the first plateau was reached at 0.064 (vacuum) or 0.116 g H<sub>2</sub>O/g dry mass (Drierite). The specimens were then exposed to 60% RH until attaining the second plateau at 0.220 (vacuum) or 0.191 g H<sub>2</sub>O/g dry mass (Drierite), and subsequently exposed to 99% RH until attaining the third plateau at 0.493 (vacuum) or 0.401 g H<sub>2</sub>O/g dry mass (Drierite).</p> </sec> <sec> <title id="sect0020">Results</title> <p id="spar0015">Exposure of the first layer of bound water to 0% RH for 5 min produced a −0.3% loss of bound water; in the second layer of bound water it caused a −3.3% loss of bound water; in the third layer it caused a −6% loss of bound water. Immersion in 100% ethanol or acetone for 5 min produced a 2.8 and 1.9% loss of bound water from the first layer, respectively; it caused a −4 and −7% loss of bound water in the second layer, respectively; and a −17 and −23% loss of bound water in the third layer. Bound water represented 21–25% of total dentin water. Chemical dehydration of water-saturated dentin with ethanol/acetone for 1 min only removed between 25 and 35% of unbound water, respectively.</p> </sec> <sec> <title id="sect0025">Significance</title> <p id="spar0020">Attempts to remove bound water by evaporation were not very successful. Chemical dehydration with 100% acetone was more successful than 100% ethanol especially the third layer of bound water. Since unbound water represents between 75 and 79% of total matrix water, the more such water can be removed, the more resin can be infiltrated.</p> </sec> </abstract>