Surface Ultrastructure of Unerupted Mature Human Enamel

Abstract

The surface structure of mature enamel in unerupted human molars was examined in the scanning electron microscope after exposure to a variety of preparational techniques. Final enamel formation was associated with more extensive developmental disturbances in the supracervical and central parts of the surfaces as compared to the cervical surface enamel. These disturbances included micropores, thin irregular fissures with rounded borders, highly irregular and porous Tomes’ processes pits, and enamel caps and protrusions and made the tooth surface very susceptible to preparational damage. Thus, dehydration with severe shrinkage, critical point drying or freeze drying techniques eventually preceded by sodium hypochlorite and ultrasonic treatment induced a variety of focal holes including intermediate forms between enamel caps and true holes. The study further demonstrated that human enamel at the time of eruption is highly porous with a variety of established diffusion pathways into the subsurface enamel. These findings should be taken into account when surface features, observed in erupted teeth of unknown origin and age are to be interpreted.

Replica of human dentin treated with different desensitizing agents: a methodological SEM study in vitro

“…Fragments or dentin discs have been frequently used for this purpose, especially when associated with SEM (2). Nevertheless, tooth specimen preparation techniques for SEM may introduce artifacts that make the correct interpretation of the results difficult or even unviable (8,15). In dentinal reactivity tests with desensitizing agents, the laboratory sequences for specimen fixation and dehydration for Figure 8.…”

Understanding Nano-Anatomy of Healthy and Carious Human Teeth: a Prerequisite for Nanodentistry

“…The hydroxyapatite in enamel is arranged in crystallites bundled in rods, which run from the DEJ to the tooth surface. The space between rods, termed inter-rod enamel, contains more organic material than the rods themselves [26]. White et al [27] showed the importance of biological organization, stating that fracture toughness of enamel is three times larger than that of pure apatite crystallites.…”

Clinical Evaluation of DIAGNOdent in Detection of Occlusal Caries in Newly Erupted Noncavitated First Permanent Molars in Caries-Active Children

“…[1][2][3] Early diagnosis of caries, especially among caries-active children, is therefore critical for protecting newly erupted first molar teeth from being lost to caries. 2 However, the diagnosis of noncavitated occlusal caries is generally considered problematic because the appearance of early caries in the occlusal surface-as a white-spot lesion, with brown discoloration around the fissure-may not be noticed by the naked eye, despite the high possibility of the presence of dentinal caries beneath discolored fissures; in fact, 60% to 71% of seemingly intact teeth have been found to have dentinal caries.…”

“…[1][2][3] In addition, permanent first molars erupt at a time when oral hygiene is not fully maintained, and they continue to generate retention regions for food remnants until they grow to full, functional occlusion. 4,5 Because of their recent eruption, as well as the anatomic configuration of their occlusal surfaces, these teeth are at risk of developing caries.…”