Biomedical Engineering Reference
In-Depth Information
one part of a complex problem [ 130 ]. The success of clinical restorations depends
on a variety of factors, including proper technique, appropriate materials, and
proper patient selection [ 130 ].
In vitro and in vivo studies have suggested that several factors inhibit the
formation of a durable d/a bond. These factors include: (1) water sorption and
hydrolysis of the adhesive resin; (2) inadequate monomer/polymer conversion of
the infiltrating adhesive; (3) incomplete resin infiltration; and (4) incomplete
solvent evaporation [ 79 , 82 , 86 , 93 ]. One strategy for reducing hydrolytic degrada-
tion involves selectively modifying methacrylate side chains so that they are both
water-compatible and esterase-resistant [ 115 - 117 , 122 , 131 , 132 ].
Inadequate monomer/polymer conversion may be addressed by including
photoinitiators that are compatible with the hydrophilic components [ 81 ]. It is
clear that full realization of our efforts to develop durable dentin adhesives
demands quantitative information about solubility, water miscibility, distribution
ratio, and phase partitioning behavior [ 85 , 133 ].
The failure of the d/a bond, in concert with reports of increased levels of
cariogenic bacteria at the perimeter of composite materials, points to an interesting
interplay between microbiology and adhesive degradation as key elements in
the premature failure of moderate-to-large composite restorations. Adhesion of
S. mutans to surfaces in the mouth creates an environment that supports the
subsequent attachment and growth of other bacterial species, ultimately forming a
micro-ecosystem known as a biofilm. Dental plaque biofilm cannot be eliminated
[ 134 ]. It may, however, be possible to reduce the pathogenic impact of the biofilm
at the margin of the composite restoration by engineering novel, durable dentin
adhesives [ 135 ].
Acknowledgements The authors gratefully acknowledge research support from NIH/NIDCR
grants DE014392 (PS), DE022054 (PS, JSL), and K23DE/HD00468 (BSB). The authors gratefully
acknowledge the numerous oral surgeons and their staff who assisted us with these projects.
1. Beazoglou T, Eklund S, Heffley D, Meiers J, Brown LJ, Bailit H (2007) Economic impact of
regulating the use of amalgam restorations. Public Health Rep 122(5):657-663
2. Murray PE, Windsor LJ, Smyth TW, Hafez AA, Cox CF (2002) Analysis of pulpal reactions
to restorative procedures, materials, pulp capping, and future therapies. Crit Rev Oral Biol
Med 13(6):509-520
3. Simecek JW, Diefenderfer KE, Cohen ME (2009) An evaluation of replacement rates for
posterior resin-based composite and amalgam restorations in US Navy and Marine Corps
recruits. J Am Dent Assoc 140(2):200-209
4. Bernardo M, Luis H, Martin MD, Leroux BG, Rue T, Leitao J, DeRouen TA (2007) Survival
and reasons for failure of amalgam versus composite posterior restorations placed in a
randomized clinical trial. J Am Dent Assoc 138(6):775-783
5. DeRouen TA, Martin MD, Leroux BG, Townes BD, Woods JS, Leitao J, Castro-Caldas A,
Luis H, Bernardo M, Rosenbaum G, Martins IP (2006) Neurobehavioral effects of dental
amalgam in children: a randomized clinical trial. JAMA 295(15):1784-1792
Search WWH ::

Custom Search