title: Biological bases of dentin hybridization.
abstract: The aims of this study were threefold: (1) to characterize and quantify the number, diameter and surface area of exposed dentinal tubules on the cross section of the human coronal dentin; (2) to determine if any such differences in these properties arise in relation to the distance from the dentinoenamel junction; and (3) to evaluate whether such differences can influence dentin hybridization. To accomplish these aims, scanning electron microscopy comparative observation was carried out on 60 prepared human premolars, which were divided into three groups of 20 samples each. The three sample groups were cut as follows: (1) in the central fissure region, one millimeter from the enamel-dentine junction; (2) halfway between the enamel-dentine junction and the pulp; and (3) one millimeter from the roof of the pulp chamber. Using one-way analysis of variance (one-way ANOVA) and a regression linear model, the data enumerated below were obtained. First, the mean number of the tubule openings was 19600/mm2 on the first level, 32400/mm2 on the second and 42300/mm2 on the third. The mean tubule diameter on the first level was 0.67 microm, 1.52 microm on the second and 2.58 microm on the third. Finally, exposed tubules on the first level occupied 2.79% of of total dentinal surface area, 23.90% on the second, and 87.78% on the third level. Therefore, significant statistical differences (p < 0.01) between all three groups of the specimens for all three properties were observed, as well as positive correlation between the dentin depth and each of these properties. This indicates that the dentin structural variety, which ultimately determines adhesion to dentine, involves a complex interaction between biological material (dentin) and the particular adhesion system applied.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Hospital "Dubrava", School of Dental Medicine, University of Zagreb, Zagreb, Croatia. dabrajdic@net.hr
authors.forename: Davor
authors.initials: D
authors.lastname: Brajdić
authors.forename: Ozren Mika
authors.initials: OM
authors.lastname: Krznarić
authors.forename: Zoran
authors.initials: Z
authors.lastname: Azinović
authors.forename: Darko
authors.initials: D
authors.lastname: Macan
authors.forename: Marijan
authors.initials: M
authors.lastname: Baranović
mesh_terms: D000293:Adolescent; D001840:Dental Bonding; D003738:Dental Cements; D003743:Dental Enamel / Q000648:ultrastructure; D003782:Dental Pulp / Q000648:ultrastructure; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents; D006801:Humans; D008855:Microscopy, Electron, Scanning; D055815:Young Adult
chemical_list: D003738:Dental Cements; D017220:Dentin-Bonding Agents