Characteristics of non-carious cervical lesions - an ex vivo study using micro computed tomography

Abstract

The aetiology of non-carious cervical lesions (NCCLs) is not well understood and still controversial. The aim of this ex-vivo study was to examine the morphological characteristics of NCCLs for clinical evidence of enamel loss above the cemento-enamel junction (CEJ) as suggested by the abfraction theory. Fifty extracted human teeth with various types of NCCLs were collected and scanned by micro computed tomography. The reconstructed three-dimensional models were evaluated from multiple aspects, including longitudinal cross-section series. The location of internal line angle and proximal exits of the lesions were evaluated in relation to the level of CEJ. The coronal margins of the lesions were inspected for evidence of enamel loss above the CEJ using the bucco-lingual longitudinal sectional images. Coronal margins of the lesions were located along and/or under the CEJ for all of the 50 samples. In most of the lesions, regardless of lesion type, the proximal exits and internal line angles were located below the CEJ. This study did not detect clinical evidence of enamel loss above the occlusal margin of NCCLs as would have been expected according to the general abfraction mechanism.

Loading and composite restoration assessment of various non‐carious cervical lesions morphologies – 3D finite element analysis

“…Seven models were generated, simulating a sound tooth model (SM), three NCCL morphologies (wedge shape, saucer shape and mixed shape) 10 and the restored models of all lesions types (RM) (Fig. 1).…”

“…9 The multifactorial aetiology results in various geometric forms and are classified as: wedge-shaped (WS), saucer-shaped (SS) and mixed-shaped (MS). 10 A wedge-shaped lesion is characterized by a sharp internal line angle, while a saucer-shaped lesion has a rounded internal line angle. A mixed-shape lesion has flat gingival and semi-circular occlusal walls with smooth lines and is semi-circular in shape.…”

Morphology of the Cement-Enamel Junction (CEJ), Clinical Correlations

“…With respect to non-carious cervical lesions, the CEJ is the area where a higher percentage of these are initiated (Palamara et al, 2006;Hur et al, 2011) subsequently progressing in size and depth, bringing with injuries which could subsequently affect the vitality of the tooth. For Cuniberti de Rossi & Rossi (2009), the presence of Classes 2 and 4 are certainly, along with other factors such as enamel thickness and orientation of the prisms, the most important predisposing factors for the formation of abfractions; classes that in our study obtained a lower percentage.…”

Finite element Analysis in Dentistry – Improving the quality of oral health care

“…except for fracture of enamel that was undermined by the NCCL (Hur et al, 2011). Since the location of the lesion will affect the stress conditions, combining clinical observations and finite element modeling will be essential to determine the stress factor in the initiation and development of NCCL.…”