Which of the following methods is NOT used for retention in dental fillings?

In dental practice, methods used for retention in dental fillings are aimed at ensuring that the filling material adheres securely to the tooth structure. Dentine pins, acid etching, and chemical bonding are all techniques utilized to enhance the retention of restorative materials.

Dentine pins are small metal pins inserted into the dentine to provide additional support and retention for fillings, particularly in large cavities. Acid etching involves applying an acid solution to the tooth surface to create a rough texture, which increases the mechanical retention between the tooth and the filling material. Chemical bonding refers to the use of bonding agents that create a strong adhesive interface between the tooth structure and the restorative material.

On the other hand, radiography is a diagnostic tool used to visualize the structures within the mouth, such as teeth and bone, using X-rays. It does not serve to retain filling materials but rather aids in assessing the condition of teeth, facilitating treatment planning and monitoring the results of dental work. Therefore, it is correctly identified as the method that is not used for retention in dental fillings.