Applications of scanning electron microscopy and focused ion beam milling in dental research

Abstract

The abilities of scanning electron microscopy (SEM) and focused ion beam (FIB) milling for obtaining high-resolution images from top surfaces, cross-sectional surfaces, and even in three dimensions, are becoming increasingly important for imaging and analyzing tooth structures such as enamel and dentin. FIB was originally developed for material research in the semiconductor industry. However, use of SEM/FIB has been growing recently in dental research due to the versatility of dual platform instruments that can be used as a milling device to obtain low-artifact cross-sections of samples combined with high-resolution images. The advent of the SEM/FIB system and accessories may offer access to previously inaccessible length scales for characterizing tooth structures for dental research, opening exciting opportunities to address many central questions in dental research. New discoveries and fundamental breakthroughs in understanding are likely to follow. This review covers the applications, key findings, and future direction of SEM/FIB in dental research in morphology imaging, specimen preparation for transmission electron microscopy (TEM) analysis, and three-dimensional volume imaging using SEM/FIB tomography.

The state of the art and future trends of root canal files from the perspective of patent analysis: a study design

“…Considering the limitations Fig. 16 The patents of this paper. a-b Improvement method classification percentage.…”

“…1(b), the factors affecting the performance of root canal files and their current limitations were described. For dental medical devices [15][16][17][18] in dentistry, an extensive review of literature exists but a detailed overview of root canal files is, to the author's best knowledge, missing.…”

Effect of dentine site on resin and cement adaptation tested using X‐ray and electron microscopy to evaluate bond durability and adhesive interfaces

“…The microscopic appearance of the dentine‐adhesive interface can be studied using transmission (TEM) [ 28 ] or scanning electron microscopy (SEM) [ 29 , 30 ]. Yet standard electron microscopy techniques require extensive multi‐stage specimen preparation that increases artefacts or alters investigated surfaces [ 31 , 32 ].…”

“…Multi‐stage specimen preparation of hard tissue such as dentine can involve chemical fixation, solvent dehydration, decalcification, resin‐embedding, and microtome sectioning [ 31 , 32 ]. Alternatively, a focused ion beam (FIB) can mill cross‐sections for electron microscopy observation, following simple specimen preparation such as oven‐drying and surface polishing [ 30 , 33 ]. Previously, gallium FIB, known to cause significant beam damage [ 29 , 30 , 34 ], has been used to prepare cross‐sections or lamellae of the dentine‐adhesive interface to observe with SEM [ 20 , 30 ] or TEM [ 29 ].…”

“…Alternatively, a focused ion beam (FIB) can mill cross‐sections for electron microscopy observation, following simple specimen preparation such as oven‐drying and surface polishing [ 30 , 33 ]. Previously, gallium FIB, known to cause significant beam damage [ 29 , 30 , 34 ], has been used to prepare cross‐sections or lamellae of the dentine‐adhesive interface to observe with SEM [ 20 , 30 ] or TEM [ 29 ]. The TEM lamellae preparation is time‐consuming and yields small (<20 μm) regions of interest [ 30 , 32 , 35 ], and gallium can implant on substrates to introduce artefacts [ 36 ].…”