Wedge-shaped defect is a common disease and a chronic decay of tooth hard tissue. It mainly involve in the elderly population. Although in-depth studies have been carried out, due to the complicated etiology, its pathogenesis has not yet been fully understood. Over the past decade, with the expansion of research directions, the roles of saliva and pH value in wedge-shaped defect formation have been gradually cleared. This article reviewed the influence of saliva and pH value to the wedge-shaped defec
