Application of Optical Coherence Tomography (OCT) for Diagnosis of Caries, Cracks, and Defects of Restorations

Abstract

Optical coherence tomography (OCT) is a noninvasive technique providing cross-sectional images of a tooth structure. This review describes the use of OCT for detecting dental caries, tooth fractures, and interfacial gaps in intraoral restorations. OCT can be a reliable and an accurate method and a safer alternative to X-ray radiography.

Keywords: Caries; Diagnosis; Interfacial gap; Optical coherence tomography (OCT); Tooth fracture.

Fig. 1

Dental caries in first and second premolars. a Occlusal view before the surgical treatment. Underlying dark shadows were visually observed at the first and second premolars (arrow). SS-OCT observation was performed along red line. b Occlusal view during the cavity preparation. Presence of deep lesions with softened dentin was obvious (white arrow). c SS-OCT image at red line in (a) before cavity preparation. Bright zone indicates the increased light scattering in porous demineralized tissue (blue arrow). A strong reflection penetrating along the DEJ indicates the lesion is “cavitated” (red arrow)

Fig. 2

Mandibular first molar with occlusal pain. a Buccal view. Full coverage metal crown complicated the visual inspection and clinical diagnosis. SS-OCT observation was performed along the red line in order to image the cross-sectional view of cervical zone horizontally. b SS-OCT image at red line in (a). A strong reflection penetrating into dentin indicates presence of vertical crack in root dentin (red arrow)

Fig. 3

Clinical assessment of resin composite restoration. a Buccal view. Class V composite restoration was present with slight marginal discoloration but without any clinical symptoms. SS-OCT observation was performed along the red line. b SS-OCT image at red line in (a). Distinct white border between resin and enamel/dentin indicates “gap” (red arrow)