Imaging of human tooth enamel using ultrasound

Abstract

This paper reports the results of a complete circumferential scan of a human tooth and its underlying dentino-enamel junction using ultrasound at frequencies in the 10-MHz range. The imagery shows clearly a two-dimensional contour of the dentinoenamel junction with a depth and lateral resolution of approximately 100 microm and 750 microm, respectively. The resulting sonograph is compared with an optical micrograph of the same tooth to verify the accuracy of the ultrasonic technique. The results are a significant step toward the biolocation of submillimeter size features within the tooth volume.

Tissue mimicking materials for dental ultrasound

“…Ultrasound has previously been investigated as a complement to dental radiography as a tool to detect caries, fractures, and debonded restorations. [1][2][3][4] However, progress in dental ultrasound has been limited by a number of factors. The high acoustic impedances of dental tissues result in surface losses that limit the use of commercially available medical transducers and acoustic scanning gels since these are not acoustically matched to teeth.…”

Ultrasound in maxillofacial imaging: A review

“…[6] Culjat et al (2003) used pulsed US imaging to determine the enamel thickness. [9] Current research endeavors at expanding the usage of US in maxillofacial region, some of them directed in detection of caries, dental cracks and fractures, soft tissue lesions, periapical lesions, maxillofacial fractures, muscle thickness, and implant dentistry. [10] …”

“…[11] The High-frequency US has a long Fresnal zone and a greater depth resolution, although the tissue absorption also increases. [13] US pulse comprises a collection of frequencies called the bandwidth (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). Higher is the fundamental frequency, better is said to be the spatial resolution.…”

Evaluation of gallium-indium alloy as an acoustic couplant for high-impedance, high-frequency applications

“…There have been various attempts to image hard tissue such as bones and teeth, with water a frequently used couplant in such applications. 5,[7][8][9] Other materials have also been explored, such as oil, glycerin, and mercury. 4,10 All of these couplants proved useful, but each have their shortcomings.…”

“…2 A piezoelectric transducer was used, and contained a soda-lime glass delay line that also served as a matching layer. Since the acoustic impedances of soda-lime glass and enamel are 13.4 and 16.5 MRayl, [3][4][5] respectively, the ideal coupling material would have an acoustic impedance that is the square root of the product of the two, or 15 MRayl. 6 Additional requirements are that the coupling material has low attenuation and that it is conformable.…”