Dental OSCE (Objective Structured Clinical Examination) Practice Exam

Which of the following is NOT a function of acid etch in dentistry?

1. Increase surface area

2. Make surface for bonding agent

3. Create chemical bond

4. Increase retention tags

The correct answer is: Create chemical bond

Acid etching is a crucial procedure in dentistry, primarily used to prepare tooth surfaces for the application of bonding agents. The process involves applying a phosphoric acid solution to the enamel or dentin, leading to several important outcomes. One major function of acid etching is to increase the surface area by creating a rough texture on the tooth surface. This roughening enhances the mechanical retention of bonding materials, leading to a stronger bond when restorative materials are applied. Additionally, acid etching creates a suitable surface for the bonding agent to adhere to, providing an optimal environment for the application of restorative materials. The increased surface area and micro-roughness created by the etching process help in forming 'retention tags' – microscopic projections that increase the mechanical interlock between the substrate and the bonding agent. While some properties of the bonding agent may lead to a certain degree of chemical bonding, the primary action of acid etching is not to create a chemical bond. The bonding that occurs after etching is mainly mechanical in nature, resulting from the interlocking of the resin material with the irregularities in the surface created by the etching process, rather than a true chemical bond. Thus, stating that acid etch creates a chemical bond does not accurately reflect