Medical History Competency Practice Test 2026 – Complete Preparation Resource

Nighttime reflux exposes the mouth to gastric acid, and when a person is lying down the acid tends to pool along the palate and the tongue side of the teeth. The lingual surfaces of the maxillary anterior teeth are directly in contact with this refluxed fluid, making them the most susceptible to erosion from intrinsic acid. In contrast, buccal/facial surfaces get less exposure to the refluxate, and occlusal surfaces are more affected by wear and grinding than by chemical erosion. So the surface most characteristically eroded by nocturnal reflux is the lingual surfaces of the anterior teeth.