Why must primer be dispensed immediately during procedures?

Dispensing primer immediately during procedures is crucial to prevent evaporation. Primer is often a solvent-based material, and if it is allowed to sit exposed in the air, the solvent can evaporate quickly, leading to changes in the chemical composition of the primer. This evaporation can alter its effectiveness and reduce its ability to properly bond to the substrate, which is essential for achieving a reliable adhesion in dental applications.

Achieving optimal adhesion is a critical aspect of dental procedures to ensure that materials like restorative agents and bonding agents work effectively. Though enhancing adhesion and proper application are important aspects of using primers, if the primer has evaporated or undergone significant changes before application, even the best adhesive techniques may not be effective. Contamination is also an important concern in dental work, but it is more directly related to the handling of materials and the dental environment rather than the immediate dispensing needs of the primer itself.