HEMA diffusion from dentin bonding agents in young and old primary molars in vitro.
The objective of this study was to evaluate and compare amounts of HEMA diffusion from three dentin bonding systems in young and old primary molars at a remaining dentin thickness (RDT) of 1 mm. Occlusal cavities were prepared with RDT of 1 mm in young and old primary molars. Chambers that contain 1 ml of distilled water were attached to each tooth. The groups were treated with Total Etch+Syntac Single Component, Syntac Single Component and Clearfil SE Bond. Water eluates were analyzed by HPLC at 4 min, 24 h and 72 h. The cumulative HEMA release amounts were significantly different among all groups (p<0.05). Acid-etching significantly increased pulpward diffusion of HEMA and young primary teeth presented higher dentin permeability. Acid-etching significantly increases pulpward release of HEMA from dentin bonding systems in primary molar teeth. Young primary molars have higher dentin permeability; so the pulp should be protected with cavity liners in deep cavities. However, the dentin bonding systems can be considered safe for clinical use in primary teeth, even in deep cavities, since the released HEMA amounts are below the level of cytotoxicity.