Scanning Electron Microscopic Characterization of Sensitive vs. Insensitive Human Radicular Dentin

Abstract

Our aim was to investigate the structural changes of dentinal tubules in specimens obtained from both hypersensitive and naturally desensitized areas in wedge-shaped defects on the same exposed cervical dentin surface of a hypersensitive tooth. A new biopsy technique that makes use of a hollow, cylindrical diamond bur was designed so that specimens from exposed root dentin of vital teeth could be obtained. Twenty-two dentin biopsy pairs were divided into two groups; one was prepared for scanning electron microscopy (SEM) and the other for microradiography (MR). Small hypersensitive areas were identified by a scratch test on exposed human dentin in vivo. SEM observation of the dentin biopsies showed that the orifices of many dentinal tubules in hypersensitive areas were open and that membranous structures appeared on the walls of dentinal tubules. In naturally desensitized areas on the same dentin surface, most of the dentinal tubules were obturated with rhombohedral crystals of all sizes; membranous structures were not observed in these tubules. These results showed that hypersensitivity occurred on the exposed dentin when most of the tubular orifices were open.

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

“…The present work demonstrated that important details of dentin surfaces treated with desensitizing agents may be identified in SEM micrographs at the relatively low magnification of 1000x. This non-invasive procedure may be useful in clinical trials in substitution for dentin biopsy (20) or extraction of teeth for direct observation (9).…”

Dentin permeability: the basis for understanding pulp reactions and adhesive technology

“…Fig.11b is a 'dentin biopsy' of the surface layer with higher mineral content examined in a scanning electron microscope showing that mineral salts have precipitated in the tubules. Source: Yoshiyama et al (10). Fig.…”

Effect of a calcium-phosphate based desensitizer on dentin surface characteristics

“…Although the mechanisms of pain transmission across dentin are not fully understood, dentin sensitivity is reduced by reduction of permeability and occlusion of dentinal tubules 4,5) . The exposed patent dentinal tubule is considered the morphological etiology of dentin hypersensitivity; in vivo studies revealed that the orifices of many dentinal tubules in hypersensitive areas were open 6,7) . However, different types of hypersensitive dentin express different surface characteristics.…”