Which restoration material's strength is not affected by pins?

Composite resin is uniquely designed to achieve strength and durability independent of the use of pins for retention. This is largely due to the chemical and physical properties that allow composite resins to bond effectively to tooth structure without reliance on mechanical retention methods like pins. The bonding mechanism is facilitated by the adhesive nature of the resin itself, which can form a strong bond with enamel and dentin, maintaining its strength and integrity regardless of whether pins are used.

In contrast, other materials, such as amalgam, glass ionomer, and resin ionomer, can experience changes in strength when pins are incorporated. Amalgam relies on both the shape of the cavity preparation and the retention form, which can be compromised by any additional mechanical interventions like pins. Glass ionomer and resin ionomer also have specific bonding properties that can be impacted by the structural changes introduced by pin placements, altering their mechanical strength or effectiveness.

Thus, the independent strength of composite resin from the use of pins allows it to be a preferred option for various dental restorations where minimal invasive preparations and aesthetic results are desired.