After drilling for a few particularly deep fillings, your dentist recommended placing a crown (or cap) over your damaged tooth. When placed correctly, a dental crown looks and acts like your natural teeth, and it protects your remaining tooth against damage.

If you take great care of your dental crowns, you can expect them to last at least 5 to 15 years. For some individuals, dental crowns last even longer, as much as 25 or 30 years.

But although dental crowns present a reliable, durable way to restore your broken or cracked tooth, dental crowns also have their weaknesses. If you have or do any of the following, you can bet that your dental crown won't last nearly as long as expected.

1. You Have a Misaligned Bite

Your crown needs to align perfectly with your other teeth. When your dentist places a crown, he or she will need to carefully shape and adjust the crown to ensure that it doesn't alter your bite in anyway.

However, if your dentist made a mistake or your bite has shifted over time, the nearby teeth may hit your crown at an angle and put extra pressure and stress on the material. The pressure may cause the crown to crack and break prematurely.

2. You Chew on Hard Objects

Your teeth have the ability to cope with a great deal of force. In fact, the human jaw typically uses about 31 kg of force with the back molars while chewing. And some individuals can exert as much as 124 kg of force in their bite.

But even the strongest teeth don't hold up well when you chew on hard objects. If you regularly nibble on pens, crush ice between your teeth, bite your nails or crunch into hard candy, you'll quickly wear down your teeth, as well as your dental crown.

3. You Grind Your Teeth

Teeth grinding, or bruxism, can occur for a variety of reasons. Extreme stress or anxiety, an abnormal bite, sleep apnoea, psychiatric medications and stomach acid reflux can all lead to the condition.

If left unchecked, teeth grinding can result in numerous symptoms, including headaches, facial muscle pain, jaw joint stiffness and sleep disruption. Furthermore, teeth grinding wreaks havoc on your natural teeth and your dental crowns, wearing away the teeth and fracturing the bone or the crown material.

4. You Don't Practice Good Oral Hygiene

Dentists often use porcelain, gold or a mix of the two to create dental crowns. These materials won't decay like your natural teeth, so you can expect them to last a long time.

But just because the crowns themselves shouldn't decay doesn't mean you can neglect your oral health completely. The surrounding teeth can still develop cavities, and in some cases, decay can occur in the tooth underneath the crown.

If you don't brush and floss your teeth properly, bacteria can find their way into the small spaces of your teeth and attack your teeth at the root. Overtime, the decay can weaken the tooth and damage the gums, causing the dental crown to shift out of place.

5. You Participate in Sports Without Protection

Sports are a great way to stay in shape and improve blood flow. When you regularly participate in football, acrobatics, field hockey, martial arts or wrestling, you dramatically reduce your risk for cardiovascular disease and bone degeneration.

However, contact sports also come with a great deal of risks, especially if you forget to wear a mouthguard. Hits, bumps, strikes, falls and blows can result in a variety of dental injuries, including root fractures, tooth displacement and crown fractures. 

Talk to Your Dentist About a Replacement

If you notice that your dental crown has cracked, or if you worry that your crown may not feel as secure as it once did, schedule an appointment with your dentist. They can assess the condition of your crown to determine whether you need a replacement or adjustment.