SUMMARY The theory of abfraction suggests that tooth flexure arising from occlusal loads causes the formation and progression of abfraction lesions. The current study investigated whether reducing occlusal loading by adjusting the occlusion on a tooth during lateral excursive movements had any effect on the rate of progression of existing abfraction lesions. Recruited were 39 subjects who had two non-carious cervical lesions in the maxillary arch that did not need restoration and were in group function during lateral excursive movements of the mandible. One of the teeth was randomly selected to have the excursive occlusal contacts reduced by using a fine grain diamond bur. Centric occlusal contacts were not reduced. Impressions of the lesion were taken over a 30-month period to enable monitoring of the wear rate, and duplicate dies were poured into epoxy resin to allow for sectioning. The size of the lesions was measured using stereomicroscopic analysis of the sectioned epoxy resin dies, and the results were analyzed using an Independent t-test. No statistically significant difference in wear rates between the adjusted and non-adjusted teeth was found (p>0.05). Within the limitations of the current study, it was concluded that occlusal adjustment does not appear to halt the progression of non-carious cervical lesions; consequently, this procedure cannot be recommended.