A dental crown is often described to patients in simple terms as "a cap for your tooth" without much explanation of how it's actually fitted or what determines whether it lasts five years or fifteen. This article focuses specifically on those two questions: the fitting process, and the factors that influence a crown's longevity.
How a Crown Is Generally Fitted
Preparing the tooth — The dentist removes a portion of the tooth's outer structure to create room for the crown to fit naturally alongside surrounding teeth. The amount removed depends on the crown material and the specific tooth's condition.
Taking an impression or digital scan — A precise mould or digital scan of the prepared tooth and surrounding teeth is taken, used to fabricate a crown that fits your bite accurately.
Fitting a temporary crown — While the permanent crown is being made, a temporary crown is generally fitted to protect the prepared tooth and maintain function and appearance in the meantime.
Fabricating the permanent crown — Depending on the practice and material chosen, this may be done by an external dental laboratory, typically taking one to two weeks. In some practices, it is done with in-house milling technology, completed on the same day using digital scanning.
Fitting and cementing the permanent crown — Once ready, the crown is checked for fit, bite, and appearance, adjusted if necessary, and then permanently cemented or bonded into place.
Factors That Influence How Long a Crown Lasts
Material choice — Different crown materials (porcelain, ceramic, zirconia, metal alloys, or combinations) have different durability profiles. Zirconia, for example, is generally known for high strength, while porcelain offers strong aesthetics but may be somewhat more prone to chipping under significant force. The most suitable material depends on the specific tooth and your bite, which your dentist can advise on.
Location in the mouth — Crowns on back teeth (molars) generally experience greater biting force than those on front teeth, which can influence both material choice and expected longevity.
Oral hygiene — The margin where a crown meets the natural tooth remains susceptible to decay if not kept clean. Consistent brushing and flossing around the crown play an important role in its long-term success.
Bite forces and grinding — Patients who grind or clench their teeth place additional stress on crowns, which may affect how long they last. A night guard is sometimes recommended to help manage this.
Quality of the underlying tooth structure — A crown is only as stable as the tooth supporting it. Sufficient remaining healthy tooth structure, or in some cases a supporting post and core, generally improves the crown's stability over time.
Precision of the fit — A well-fitted crown, properly adjusted to your bite, generally distributes forces more evenly, which may support better longevity compared to a poorly fitted restoration.
Regular dental check-ups — Routine monitoring allows your dentist to catch early signs of wear, marginal breakdown, or other issues before they progress into more significant problems.
What Tends to Fail First: The Crown or the Underlying Tooth
It's worth understanding that crown "failure" can mean different things. Sometimes the crown itself chips or wears, while other times the underlying tooth develops new decay at the margin, or the cement bond weakens over time. Regular check-ups help distinguish between these scenarios early, since the appropriate response differs depending on the cause.
Signs Worth Reporting to Your Dentist
Persistent sensitivity around a crowned tooth
Any looseness or movement of the crown
Visible cracks or chips in the crown material
Pain when biting on the crowned tooth
Changes in how your bite feels
These signs don't necessarily indicate a serious problem, but are worth having assessed promptly rather than waiting for your next scheduled check-up.
Getting an Assessment
If your dentist has recommended a crown, or if you have an existing crown that feels like it needs attention, the team at Shire Smiles can assess your specific situation and discuss the most suitable material and approach.
Crown longevity varies between individuals and depends on a range of factors, and an AHPRA-registered dental practitioner is best placed to advise on what's realistic for your specific case.
About the Author This article was prepared in collaboration with the clinical team at Shire Smiles, offering dental crown treatments using a range of materials suited to individual needs. Treatment recommendations and expected longevity vary by individual and should be confirmed by an AHPRA-registered dental practitioner.
