What condition increases the heat generated during preparation?

The condition that significantly increases the heat generated during dental preparation is excessive pressure. When excessive pressure is applied during the preparation of a tooth, it leads to increased friction between the bur and the tooth structure. This friction generates heat, which can potentially lead to thermal damage to the dental pulp and surrounding tissues.

Applying too much pressure doesn't allow for adequate cutting efficiency, causing the bur to work harder and generate more heat. Therefore, it is crucial to maintain proper pressure to minimize the risk of overheating during dental procedures.

Other factors, such as water irrigation, typically serve to cool the bur and tooth structure, reducing heat generation. Slow rotational speeds can also contribute to less heat generation compared to higher speeds, as more efficient bur designs can cut through enamel and dentin with reduced friction. Chemical irritation pertains to reactions from materials or agents and does not directly affect heat generation during tooth preparation.