Anyone who has spent very much time sitting in a dental chair has probably at some point encountered the following situation. They have a tooth that has a big cavity or has broken. After examining the tooth their dentist tells them that it can be repaired but a decision needs to be made. Should the dentist place a large filling in the tooth or should they make a dental crown for it?

Dental crowns and fillings serve different purposes.

Seemingly your dentist has offered two treatments that can remedy the same situation. The dental crown will cost substantially more than the filling. The filling will just take one visit to complete while the dental crown two. Why not just take the cheaper, quicker route and have a filling placed?

Well, there can be a number of different reasons why a dentist might suggest that a dental crown should be considered for a tooth. These include greater strength, increased longevity, better tooth protection as well as allowing the dentist greater control over the tooth's ultimate cosmetic appearance.

Evaluating each of these considerations is important before a final decision is made. Many of the arguments for both crowns and fillings are discussed and animated on the pages of Animated-Teeth.com (they have allowed me to use some of their still pictures for this hub). In this article, however, we will limit our discussion to factors associated with how a dental crown's superior strength can make it the better, most predictable and possibly even the cheaper procedure, especially when the long-term is considered.

Dentists recommend dental crowns for those teeth that have sustained a significant amount of damage. Some tooth damage, such as that caused by decay or breakage, might be easy for a person to visualize or feel with their tongue. Other damage might not be so obvious, such as that internal weakening that occurs when a tooth is hollowed out during root canal treatment.

Before you can understand why it might be important to place a crown, you must understand how they differ from dental fillings. Yes, both types of dental work can be used to restore a tooth back to its original shape but the relationship that each of these has with the tooth's remaining structure is entirely different.

A) Dental fillings.

Fillings are dental restorations that sit within the walls of a tooth. So, imagine a tooth. Then imagine a tooth that has a part missing. A filling will simply fill in that missing portion so to restore the tooth back to its original shape.

Size (and shape) matters.

The size and shape of the hole that must be filled in will be paramount in determining the success of the filling. For example, in the case where a large amount of tooth damage has occurred it's easy to understand how the walls of the tooth that will hold the filling in place might be thin and weak, possibly significantly so. As another example, if the hole being filled in involves an entire corner of a tooth, it will present more of a challenge for the dentist to firmly anchor the filling in place.

Actually, the size and shape of the hole being filled will not only influence factors related to the filling but also the long-term outlook for the tooth itself. The larger the hole, the less overall inherent strength the tooth will have. Also, a large filling can act as wedge. When pressure is applied to it, the filling in turn can apply pressure to the walls holding it in place, thus causing portions of the tooth to crack or break off.

So, in the case where a large filling is being considered, how likely is it that the tooth to break again? If the tooth does break, what is the likelihood that the tooth will be seriously damaged? These are the kinds of factors that a dentist must evaluate. And all of these considerations are amplified as the size of the needed filling increases.

B) Dental crowns.

Now let's consider dental crowns and how they are different than fillings. For one thing, unlike a filling that sits within the confines of a tooth, a dental crown cups over it. And unlike a filling that can only be made out of materials that have characteristics that allow them to be used within the mouth, a crown is made in a dental laboratory.

Dental crowns offer several advantages.

Just think of all of the considerations that we have discussed that are taken out of the loop when a dental crown is placed instead of a filling. Will a dental crown break? Well sure, anything is possible. No dental restoration can be expected to last forever. But the materials that are used to create crowns are substantially stronger and therefore less likely to break than those used to make dental fillings.

Is a dental crown likely to be dislodged? Sure, crowns can come off. But the way a crown cups over and grasps around a tooth usually makes it much more secure than a large filling. And to this technique's credit, in many cases if a crown has come off it can simply be recemented. A filling does not offer this option.

Is it likely that a crowned tooth will crack or break? Once again, things can happen, but the manner in which a crown cups over a tooth allows that the biting forces that are directed onto it will be transferred to the underlying tooth in a very controlled manner. This is different from a filling where the remaining tooth and filling must both share the load, often unevenly or from a direction that overwhelms the strength of the filling or tooth, therefore resulting in fracture. Additionally, unlike with fillings, there is no wedging effect created by dental crowns. And, in fact, crowns do just the opposite, they have an effect of holding a tooth together.

So now you know some of the factors that a dentist must weigh in their mind as they evaluate a tooth and determine if they should suggest that a crown or a filling should be placed. You may, however, be wondering why a dentist would offer both solutions as a remedy, when clearly the dental crown has some significant advantages.

To close this hub up we'll just leave you with this (admittedly exaggerated) comparison. You might be able to cross the Atlantic in a dingy but you'll do so more comfortably on an ocean liner because that's the liner's intended purpose. Choosing between dental filling and a crown can be a similar comparison. A filling may be able to replace large portions of a tooth that are missing but a dental crown can do so more predictably. That's why dental crowns exist.

I would like to thank WMDS,Inc./ Animated-Teeth.com for giving me their permission to use their images for this hub.