Inhibition of endogenous human dentin MMPs by Gluma.
OBJECTIVE
The objective of this study was to determine if Gluma dentin desensitizer (5.0% glutaraldehyde and 35% HEMA in water) can inhibit the endogenous MMPs of dentin matrices in 60 s and to evaluate its effect on dentin matrix stiffness and dry mass weight.


METHODS
Dentin beams of 2 mm×1 mm×6 mm were obtained from extracted human third molars coronal dentin. To measure the influence of Gluma treatment time on total MMP activity of dentin, beams were dipped in 37% phosphoric acid (PA) for 15 s and rinsed in water. The acid-etched beams were then dipped in Gluma for 5, 15, 30 or 60 s, rinsed in water and incubated into SensoLyte generic MMP substrate (AnaSpec, Inc.) for 60 min. Controls were dipped in water for 60 s. Additional beams of 1 mm×1 mm×6 mm were completely demineralized in 37% PA for 18 h, rinsed and used to evaluate changes on the dry weight and modulus of elasticity (E) after 60 s of Gluma treatment followed by incubation in simulated body fluid buffer for 0, 1 or 4 weeks. E was measured by 3-pt flexure.


RESULTS
Gluma treatment inhibited total MMP activity of acid-etched dentin by 44, 50, 84, 86% after 5, 15, 30 or 60 s of exposure, respectively. All completely demineralized dentin beams lost stiffness after 1 and 4 weeks, with no significant differences between the control and Gluma-treated dentin. Gluma treatment for 60 s yielded significantly less dry mass loss than the control after 4 weeks.


CONCLUSIONS
The use of Gluma may contribute to the preservation of adhesive interfaces by its cross-linking and inhibitory properties of endogenous dentin MMPs.
Department of Restorative Dentistry, School of Dental Medicine, University at Buffalo, Buffalo, NY, USA. Electronic address: cs252@buffalo.edu.
Camila
C
Sabatini
Department of Orthodontics and Pediatric Dentistry, Universidade Estadual Paulista - UNESP, Araraquara Dental School, Araraquara, São Paulo, Brazil.
Débora L S
DL
Scheffel
Department of Orthodontics and Pediatric Dentistry, Universidade Estadual Paulista - UNESP, Araraquara Dental School, Araraquara, São Paulo, Brazil.
Régis H
RH
Scheffel
Department of Oral Biology, College of Dental Medicine, Georgia Regents University, Augusta, GA, USA.
Kelli A
KA
Agee
Department of Oral Biology, College of Dental Medicine, Georgia Regents University, Augusta, GA, USA.
Katelyn
K
Rouch
Department of Cariology and Operative Dentistry, Tokyo Medical and Dental University, Tokyo, Japan.
Masahiro
M
Takahashi
Department of Biomedicine, University of Trieste, Trieste, Italy; IGM-CNR, Unit of Bologna c/o IOR, Bologna, Italy.
Lorenzo
L
Breschi
Department of SAU&FAL, University of Bologna, Bologna, Italy.
Annalisa
A
Mazzoni
Institute of Dentistry, University of Oulu and Oulu University Hospital, Oulu, Finland.
Leo
L
Tjäderhane
Department of Endodontics, College of Dental Medicine, Georgia Regents University, Augusta, GA, USA.
Franklin R
FR
Tay
Department of Oral Biology, College of Dental Medicine, Georgia Regents University, Augusta, GA, USA; Highly Cited Investigator of King Abdulazis University School of Dentistry, Jeddah, Saudi Arabia.
David H
DH
Pashley
D003804:Dentin / Q000201:enzymology*; D005976:Glutaral; D006801:Humans; D066298:In Vitro Techniques; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D011109:Polymethacrylic Acids; D011480:Protease Inhibitors / Q000494:pharmacology*
D011109:Polymethacrylic Acids; D011480:Protease Inhibitors; C044372:Gluma; D020782:Matrix Metalloproteinases; D005976:Glutaral
Degradation; Dentin collagen; Glutaraldehyde; Matrix metalloproteinase; Mechanical properties; Proteolytic activity