As Dr. McCubbin’s letter demonstrates, the subjects of occlusion and abfraction seem more attended by religion than science. Clinical observation may be colored by preconceptions, often leading multiple clinicians to reach different conclusions from the same clinical situations.
Our study, designed by clinicians and researchers, used a scientific approach in an effort to establish and maintain objectivity. Dr. McCubbin correctly notes that the etiology of some cervical lesions may be both erosion and abrasion. However, this is generally obvious since the evidence of erosion usually extends coronal to the typical margins of toothbrush abrasion, presenting as an atypical abrasion lesion.
The existence of abfraction remains controversial. As our article observes, the findings do not prove its existence. However, of the 99 cervical lesions identified, 15 did not exhibit the clinical characteristics of either toothbrush abrasion or erosion. These lesions presumably represent other pathology. Since an abnormally high percentage of these lesions occurred on teeth that demonstrated premature occlusal contacts, these 15 unknown lesions may represent abfraction.
Clinical judgment is needed in determining the need for occlusal adjustment prior to restoring cervical lesions. If the lesions were abfraction, removal of premature contacts would be wise to prevent further tooth flexure followed by restoration failure.
