A qualitative assessment of non-carious cervial lesions in human teeth

Opinions vary about the causes of non-carious cervical lesions (NCCLs). They have been attributed to excessive tooth brushing (abrasion), effects of exogenous or endogenous acids (corrosion), and flexion of teeth from occlusal loads (abfraction). Objective: Our aims were to examine the micro-wear detail of NCCLs in a collection of extracted teeth under scanning election microscopy (SEM) and to look for evidence of abrasion and corrosion in these lesions. Methods: Twenty-four extracted teeth with NCCLs were selected from a collection in the Adelaide Dental School. Negative replicas of NCCLs were obtained in polyvinyl impression material (Light Body Imprint ™II Garant™, 3M ESPE) and viewed under SEM. Results: All NCCLs were located below the cemento-enamel junction (CEJ) and they displayed a variety of wedge-shaped appearances. Abrasion was characterized by the presence of horizontal scratch marks, presumably caused by toothbrush and/or dentrifice, while corrosion was characterized by a smooth amorphous surface which at times displayed open dentinal tubules. There was evidence of abrasion in 19 (79.2%) teeth and corrosion in 23 (95.8%) teeth. Eighteen (75.0%) of the 24 teeth displayed evidence of both abrasion and corrosion, whereas 6 (25%) teeth displayed evidence of either abrasion or corrosion. Horizontal furrows were noted in 13 (54.2%) teeth. These furrows had smooth edges, with a corrosive appearance, but no evidence of abrasive scratches. They ranged in width from 5-250 µm. All NCCLs with furrowing displayed evidence of corrosion. Conclusion: Based on microscopic assessment of a sample of extracted teeth, it appears that abrasion and corrosion are common associated aetiological factors in the formation of wedge-shaped NCCLs. This project was supported by the Dental Board of South Australia.