Crowns, also called caps which is a lay term, is defined as an indirect (made outside the mouth) restoration that replaces the major part of the tooth. What that means is that when a tooth has suffered damage either through decay, breakage chipping or root canal therapy that involves more than one third of the tooth, a filling is no longer suitable.
There is a huge difference between fillings and crowns in terms of strength. What most people don't realize is that fillings actually weaken teeth, not strengthen them. The purpose of a filling is simply to fill a hole in a tooth much like spackle fills a hole in drywall with no strength. Could you imagine hanging a painting on a screw that was placed in spackle? Well, when you place in a filling that extends into a compressed functional part of the tooth, that is essentially what is happening. The filling actually draws strength from the remaining surrounding tooth structure which is why twice as much tooth as filling is required and when fillings violate this ratio, you see cracking and breaking of the surrounding tooth structure resulting in a more aggressive crown than the one that would have been done in the first place.
Understanding Dental Crowns
When a tooth suffers this level of damage, the tooth is numbed and prepared. Preparation involves reshaping the tooth to the proper height and shape so as to receive and support the crown that slips over and fits onto the tooth like two jigsaw puzzle pieces fitting together or a hand sliding into a custom made glove. Traditionally and unfortunately in 95% of offices, the next step is take a mold/impression of the prepped tooth to send off to the lab and then make a temporary crown that the patient wears for 2-4 weeks until the permanent crown comes back from the lab.
Crowns can be made of several different materials. There is a wide range of monolithic (one layer) materials and layered materials that the dentist can choose from depending on the situation. Unfortunately, most dentists do not have a full understanding of the various materials' properties and therefore, they are "one trick ponies" that use the same material all the time in every situation no matter what and the results show. They cannot create exact esthetic matches and/or they experience functional failures from the wrong material being chosen for a complex bite situation. Also, the fact that the prepped tooth has been sitting for 2-4 weeks has allowed the precious collagen fibers of the tooth to dry out and they are now less receptive to the bonding agent that is used to bond the crown to the tooth.
A Customized Approach Sets Dr. Stanton Apart
Once the tooth is prepped, our Stanton Method takes over and we digitally scan the tooth, design the new crown using 3D software and mill the new crown in our CNC milling unit out of the strongest ceramic available in under ten minutes. Once it is milled, it may or may not go into a furnace depending on if additional coloring is required. The final step in bonding it to the prepped tooth 10-30 minutes after the tooth is prepped resulting in the highest possible bond strength to the tooth and the lowest possibility of contamination.
The crown is done in one visit, with one dose of anesthesia and at the highest possible bond strength because the prepped tooth is addressed so quickly at the correct color because it is matched directly to the adjacent teeth, not in some lab off a prescription or photos. By doing the crown this way, the dentist is able to create a crown that 1. fits better 2. is stronger 3. matches perfectly 4. bonded to the tooth with highest possible strength 5. inconvenience of wearing a temporary and waiting two weeks eliminated 6. entire process is controlled by one person eliminating errors.
Why don't all dentists do crowns this way? The answer is that the process is very expensive and very hard to learn and master. So how much extra do we charge for this superior service and product? The answer is ZERO. All crowns are definitely not created equal.