What causes sensitivity to hot and cold foods after cavity preparation and placement of GIC in an upper incisor tooth?

Sensitivity to hot and cold foods following cavity preparation and the placement of glass ionomer cement (GIC) in an upper incisor tooth is primarily caused by mechanical trauma incurred during the cavity preparation phase. During this process, the dental clinician removes decayed tooth structure, which can lead to the exposure of dentin and potentially nerve endings. This mechanical disruption can create pathways for thermal stimuli to reach the nerves more easily, resulting in heightened sensitivity to temperature changes.

Understanding this mechanism is critical, as it shows that the sensitivity is a direct response to the manipulation of tooth structure rather than due to factors like chemical reactions or heat from the GIC itself. While chemical reactions and the setting of GIC can contribute to post-operative sensitivity, they do not typically account for the immediate sensitivity associated with the exposure of dentinal tubules created during cavity preparation. Likewise, dietary habits may influence overall tooth sensitivity but are not the direct cause linked to the timing of sensitivity after the procedure. Thus, the trauma from the preparation is the primary reason for the heightened sensitivity experienced by patients.