What is a significant disadvantage of PFM crowns compared to resin-bonded crowns?

The significant disadvantage of porcelain-fused-to-metal (PFM) crowns compared to resin-bonded crowns is the greater amount of tooth structure that must be removed to accommodate the crown. PFM crowns require a specific amount of reduction to ensure that both the metal and porcelain components can fit adequately onto the tooth. This procedure can lead to extensive preparation, potentially compromising the tooth's structural integrity and increasing the risk of future complications like sensitivity or fractures.

In contrast, resin-bonded crowns, also known as "Maryland bridges," are designed to be less invasive. They generally require minimal preparation, allowing them to be bonded directly to the underlying tooth structure with less removal of tooth tissue. This preservation of natural tooth structure is advantageous, especially for patients seeking conservative treatment options.

While factors like cost, construction time, and aesthetic failure risk are valid considerations when comparing dental restorative options, the significant impact on tooth structure removal makes it a pivotal concern when choosing between PFM crowns and resin-bonded crowns.