Natural teeth are incredibly strong, built to resist wear and tear from millions of chewing cycles. The hard outer enamel layer of teeth gives wear resistance while the dense inner core provides toughness and flexibility. Together they create a strong and elastic structure that stretches and bends under load to dissipate heavy forces.
Teeth lose much of this strength and durability once they have been filled with traditional non-adhesive methods. Stress cracks around old fillings are common and deepen with time, putting the tooth at increased risk of splintering. The longer a filling has been in place and the more stress it is under, the higher the risk of tooth fracture.
Amalgam metal fillings often perform well over several years in terms of surface wear, but cause significant weakening of the surrounding tooth structure and often allow decay-causing bacteria deep within the tooth as they age and corrode.