Sealing properties of a self-etching primer system to normal caries-affected and caries-infected dentin.
OBJECTIVE
To compare the ability of an experimental antibacterial self-etching primer adhesive system to seal exposure sites in normal, caries-affected and caries-infected human dentin.


METHODS
30 extracted human third molars were used within 1 month of extraction. 10 intact normal teeth comprised the normal group. 20 teeth with occlusal caries that radiographically extended halfway to the pulp were excavated using caries-detector solution (CDS) and a #4 round carbide bur in a slowspeed handpiece. Half of those teeth were fully excavated free of CDS-stained material without exposing the pulp, and were designated as the caries-affected dentin group. The remaining 10 teeth were excavated as close to the pulp as possible without obtaining an exposure, but whose dentin continued to stain red with CDS; this group was designated as the caries-infected dentin group. The remaining dentin thickness in all of the specimens in the other two groups was then reduced to the same extent as the caries-infected group. Direct exposures of the pulp chamber were made with a 1/4 round bur in the normal dentin or a 25 gauge needle in the other two groups. After measuring the fluid flow through the exposure, the sites were then sealed with an experimental antibacterial fluoride-containing self-etching primer adhesive systems (ABF). Fluid conductance was remeasured every week for 16 weeks.


RESULTS
The fluid conductance through the exposure fell 99% in all groups following resin sealing. The seals of normal and caries-affected dentin remained relatively stable over the 16 weeks, while the seals of caries-infected dentin gradually deteriorated, reaching significance at 8 weeks. TEM examination revealed very thin (ca. 0.5 mm) hybrid layers in normal dentin, 3-4 microm thick hybrid layers in caries-affected dentin and 40 microm thick hybrid layers in caries-infected dentin. The tubules of caries-infected dentin were enlarged and filled with bacteria. Resin tags passed around these bacteria in the top 20-40 microm thereby encapsulating them in resin.
Lee
Kwang-Won
KW
Department of Conservative Dentistry, School of Dentistry, Chonbuk National University, Chonju, Korea.
Son
H-H
HH
Yoshiyama
Masatoshi
M
Tay
Franklin R
FR
Carvalho
Ricardo M
RM
Pashley
David H
DH
D000134:Acid Etching, Dental; D002327:Cariostatic Agents / Q000737:chemistry; D001840:Dental Bonding; D003731:Dental Caries / Q000382:microbiology / Q000473:pathology*; D003737:Dental Cavity Preparation; D003785:Dental Pulp Capping; D003789:Dental Pulp Exposure / Q000628:therapy; D003804:Dentin / Q000382:microbiology / Q000648:ultrastructure*; D003809:Dentin, Secondary / Q000382:microbiology / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005122:Exudates and Transudates; D005459:Fluorides / Q000737:chemistry; D006801:Humans; D008689:Methacrylates / Q000737:chemistry; D008854:Microscopy, Electron; D009943:Organophosphorus Compounds / Q000737:chemistry; D011726:Pyridinium Compounds / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013997:Time Factors
D002327:Cariostatic Agents; D017220:Dentin-Bonding Agents; C074230:MDP adhesion promoting monomer; D008689:Methacrylates; D009943:Organophosphorus Compounds; D011726:Pyridinium Compounds; D019279:Resin Cements; C089392:methacryloyloxydodecylpyridinium bromide; C005044:hydroxyethyl methacrylate; D005459:Fluorides