Читать книгу Caries Excavation: Evolution of Treating Cavitated Carious Lesions - Группа авторов - Страница 42

Especially for anterior teeth, fibre optic transillumination (FOTI) is an easy, inexpensive, and fast method to improve the visualisation of the depth of approximal decay. A bright light source is necessary to transilluminate the teeth. Light is applied to the side of the tooth and its transmission observed from either the opposing side or occlusally in the case of molars and premolars. Because light is scattered more in carious dental tissue than in sound dental tissue, caries appears darker against the healthy surrounding tissues. Thus, FOTI can assist the judgement as to whether the lesion is confined to enamel or if it has already extended to dentine because it enhances the contrast between sound and carious tissue. However, it is not possible to see cavitation or lesion activity with transillumination. Temporary tooth separation with a spatula or gentle flossing can add valuable information on surface continuity [25]. For premolars and molars, the digitised FOTI (DIFOTI), where a charge-coupled device sensor replaces the human eye, has produced heterogenous results with limited evidence [52]. Compared to radiographs, for detecting enamel carious lesions, a better agreement with the reference standard was reported for DIFOTI, while the detection of dentinal carious lesions was similar [65]. However, differences between reported studies might be attributable to inadequate light source or insufficient calibration [66].

Recently, a device with advanced near-infrared light transillumination (NILT) technology has been marketed and validated in clinical studies (DIAGNOcam, KaVo). This device consists of an intraoral camera with a wide-angle objective. The light source operates on a near-infrared wavelength of about 760 nm. Two branches illuminate the apical region from the oral and buccal aspect; the light enters the tooth via the roots, and the illuminated tooth is viewed from the occlusal aspect. This method is primarily suitable for approximal caries detection. Sound enamel looks shiny and transparent because light is transmitted in an unhampered way, while approximal enamel lesions are depicted as grey shadows. Because lesion depth in dentine is visible only in very deep dentine lesions for diagnostic purposes, the geometry of the approximal enamel lesion as viewed from the occlusal aspect is linked to lesion depth [67]. It has been found that an enamel shadow in broader contact with the enamel-dentine junction is indicative of a dentinal carious lesion, and in a clinical trial with 127 lesions in 85 patients the agreement between NILT and bitewing radiography for dentine carious lesion detection was reported to be almost 100% [68]. However, approximal lesions restricted to enamel were less likely to be reliably detected with interexaminer reliability of 0.51 (weighted kappa) [69].

Unfortunately, with NILT it is neither possible to detect surface cavitation nor to visualise approximal cervical secondary lesions, because the restauration hampers light transmission. For occlusal surfaces, no validated lesion detection criteria have been described so far.