A bonding system is considered _______ in relation to mechanical retention.

A bonding system is considered supplemental in relation to mechanical retention because it enhances the adhesive properties between dental materials and the tooth structure. Mechanical retention relies on the physical interlocking of materials, which provides stability and resistance to dislodgement. However, bonding systems contribute an additional layer of adherence that works alongside mechanical retention.

This supplemental effect is particularly important in situations where mechanical retention alone may not be sufficient, such as with specific restorative materials or in challenging anatomical situations. By providing a strong bond to the tooth, the bonding system increases the overall retention and longevity of the restoration. Therefore, the terminology of "supplemental" accurately describes the role of bonding systems in enhancing the effectiveness of mechanical retention in dental procedures.