Dental crowns in an hour? –
The crown-in-1-hour procedure.
If you’ve read our page that outlines the crowning process The steps., you know that it typically takes two appointments, usually spaced about two weeks apart, for a dentist to make and place a dental crown for their patient.
As an alternative to this ordeal, some dentists offer crown-in-an-hour service where in just a single appointment, with the patient sitting in the dental chair for as little as an hour, the placement of a tooth’s crown is fully completed (start to finish).
How are single-visit crowns possible?
In-one-hour placement is made possible via the application of CAD/CAM technology.
- CAD stands for “computer-aided design.” – When making a crown with this technology, the tooth’s impression is taken (the copy of it in its trimmed-down form) and fed into a computer.
Software is then used to meld the tooth’s prepared shape with preprogrammed stock tooth forms, the result of which is the design of a customized crown for the patient.
- CAM stands for “computer-aided manufacturing.” – In-an-hour restorations are fabricated via a milling machine that grinds them out of a single block of dental ceramic.
What are some of the brand names associated with this technology?
The first brand to offer chairside (in-office) CAD/CAM dental units was Cerec®. Other brand names associated with chairside equipment include: Procera®, E4D®, Planmeca®, Galaxy Biomill®, Glidewell®, Carestream® and Roland DGA®.
What are the steps of the crown-in-one-hour procedure?
Many of the steps performed when having a one-visit crown placed are exactly the same as when conventional crowning technique The steps. is performed. We explain in our outline below.
The steps needed for in-an-hour (single-appointment) crown placement.
- Your tooth and its surrounding gum tissue are anesthetized (numbed up). – This step is no different than with other dental procedures. (This page explains more about getting dental injections. And why some hurt.)
- Your dentist then “prepares” (shapes) your tooth using their dental drill. – Once again, this is no different than with conventional crown placement.
We outline the requirements for tooth reduction here Amounts.. Since 1-hour crowns are all-ceramics What’s this?, the amount of tooth trimming needed (on all surfaces of the tooth) typically lies on the order of 2mm (a little more than 1/16th of an inch).
- An optical impression What’s this? of your prepared tooth is then taken and uploaded into the CAD software.
The type of unit used is typically a hand-held, wand-like intraoral scanner (camera). It records both the shape of your prepared tooth and its neighbors. A second scan is taken of the teeth on the opposing dental arch (the teeth your crown will bite against).
- The software proposes a design for your crown. – Your dentist always has override control over your restoration’s final design. With modern systems however, the software’s proposed form typically needs only minimal modification.
- A block of dental ceramic that matches the shade of your teeth is placed in the CAM unit. – Two frequently used ceramics are lithium disilicate and zirconia Why they’re good choices..
- The CAD software then directs the CAM milling machine in how to grind the block down to create the crown it’s designed for your tooth. – The milling process may take as little as 10 to 15 minutes, depending on the capabilities of the CAD/CAM unit used and ceramic selected.
- The finish of the restoration is refined and its fit evaluated. – The dentist will have to trim off the completed crown’s sprue (the handle by which the milling machine manipulated the ceramic block while doing its work).
They’ll also need to check the fit of the crown on its tooth, and its contact with neighboring teeth. Additionally, they’ll need to check its “bite.” (This process is referred to as “trying in” the crown. The steps.)
- Once satisfied, the dentist can make plans to go ahead and permanently cement the crown The steps. onto your tooth.
Some ceramics are milled in their softer precrystallized (“blue block,” “green state”) form (which allows for easier, more rapid milling). If so, the crown is processed in a high-heat oven before cementation (this step increases the ceramic’s strength and hardness).
Heat treatment can also be used to glaze the crown’s surface. During this process, ceramic stains can also be fused to the crown so to selectively tint its shade.
Procedure differences: In-an-hour vs. conventional technique.
While similar, there are some very distinct differences between the steps of single-visit and conventional crown placement.
- Optical impression taking. – With conventional technique, your dentist takes your tooth’s impression by way of squishing impression putty over it and letting it set.
With one-hour technique, the tooth’s impression is acquired optically by taking a picture of it using a camera attached to the design (CAD) computer.
- There’s no need for a temporary crown. – Since your permanent crown is made and placed during the same appointment, there’s no need for your dentist to place a temporary.
- The way your tooth is prepared may be different. – By definition, a crown milled out of a single block of ceramic is an all-ceramic crown. And as such, the shape of the tooth it rests on, especially where its edges seat, must have a specific design for the best crowning outcome.
To your dentist, this shape vs. what’s needed for conventional (porcelain-metal or all-metal) crowns is quite significant. But to you, this difference will be so minute that it’s unnoticeable.
How long does placing a single-appointment crown really take?
Despite what’s advertised, the phrase “crown in an hour” is a bit of a misnomer.
- You can expect your one-visit crown placement to take around 1.5 to 2.5 hours to actually complete.
- The good news is that for some of the time (about 30 to 45 minutes or so during the middle of your appointment) you can be up and relaxing. This is the time period during which your crown is being designed, fabricated and refined.
Possibly the most truthful way to state the in-one-hour claim is that it refers to about how much time you’ll actually spend in your dentist’s chair.
How good are single-visit, one-hour dental crowns?
Are they better than conventional ones?
No, not at all. What you’re buying is the convenience of a relatively quick, one-appointment solution for your tooth’s dental needs. There’s nothing superior about the type of restoration placed. An equivalent crown could be made conventionally.
Are they worse?
No, probably not. Like we just stated, your new one-hour crown might be essentially identical to one your dentist would otherwise have placed using a conventional technique.
Instead of the above questions, the right one to ask is really:
Does the type of 1-hour all-ceramic crown that will be placed make an acceptable choice for your tooth?
As mentioned above, single-visit, 1-hour crowns are a type of all-ceramic restoration. Additionally, they have a monolithic construction, referring to the fact that they are milled out of a single block of ceramic. And while this type of construction does have some substantial advantages, it also has some distinct trade-offs.
They can include factors such as crown strength, durability and esthetics, each of which can be significantly influenced by the specific type of ceramic that the crown is milled from. Discussed more fully here.
Use the link above and educate yourself about this type of crown while keeping your own situation in mind. Then quiz your dentist as to if or why not your concerns can be expected to be an issue.
Having an all-ceramic crown placed can make a great choice in many situations. But only having to sit for one appointment may not be much of an advantage if your new restoration can’t provide predictable, lasting service or only has a mediocre appearance.
What are the advantages of in-an-hour dental crowns?
One big advantage of single-visit crowns is that of convenience. Having one placed is one-stop shopping. In just a single appointment, all of your tooth’s dental needs are taken care of.
b) Your dentist’s office performs all of the steps.
In most cases, the actual work of making a patient’s crown is performed by a dental laboratory. The impression of your trimmed tooth is sent to them. Then, following the several days required to fabricate your restoration, it is delivered to your dentist’s office.
In times of uncertainty, like the 2020 Coronavirus (COVID-19) pandemic, the availability of 1-hour crowning service can offer a significant advantage. As an example, a scenario may evolve where your tooth has broken. Your dentist deems the event an emergency and offers to evaluate it.
If they offer 1-hour service (the situation where the crown is made right in their own office by machine), it would be possible for them to fully complete your treatment (a convenient and mind-easing outcome).
Dentists who instead must coordinate with a dental laboratory, could instead only temporize your tooth and plan to have you return for your definitive treatment at a later date, whenever that might ultimately be. In the meantime, you and they will need to monitor the status of your temporary restoration.
b) Advantages of in-1-hour vs. conventional crown placement procedure.
Additional advantages have to do with how the procedure is performed. Some steps are different (and easier), others are omitted entirely.
- Fewer dental shots. – Since you just have to sit through a single appointment to get your new crown, you won’t have to have your tooth numbed up additional times during following appointments.
(Having said that, during the crown placement appointment associated with conventional crowning procedure, anesthetic isn’t always required.)
- Taking your tooth’s impression is easier. – Because the information about your tooth’s shape needs to be converted into digital form for the CAD software, impressions for one-visit restorations are taken optically via a hand-held camera (intraoral scanner) attached to the CAD/CAM unit.
That means if you’re prone to gagging when conventional impressions are taken (which involves trays filled with putty), you’ll have one less hurdle to endure.
- There’s no need for a temporary crown. – Temporaries take at least a few minutes of time to make. And wearing one involves their set of potential problems and needed precautions View the list..
Because when single-visit technique is used a temporary isn’t needed (because your crown will be made during your appointment), you reap the benefits of not having to have one.
Does getting a one-hour crown cost more?
Maybe, but not necessarily.
- A dentist’s fees for different types of crowns usually do vary Examples.. But typically just by the restoration’s type and not the fabrication method used.
Having said that, due to the expense of the equipment needed to make in-office restorations, a dentist might find that they must charge more for placing in-one-hour crowns than they would for equivalent restorations crafted by a dental laboratory. (And therefore have a higher fee than surrounding dentists for all-ceramic crowns in general).
However, this will most likely be determined by how much of this kind of work the dentist performs. High-volume practices will be in a better position to reap the rewards of efficiency and productivity that this technology can offer.
- As a second scenario, due to a demand for one-hour service, a dentist may find that they can charge more for single-visit crowns and therefore do.
Page references sources:
Anusavice KJ, et al. Phillip’s Science of Dental Materials. Chapter: CAD-CAM Processing of Ceramics.
Griffin JD. CAD/CAM Restorations: Achieving Excellence and Simplicity.
Miyazaki T, et al. A review of dental CAD/CAM: current status and future perspectives from 20 years of experience.
Rosenstiel SF, et al. Contemporary Fix Prosthodontics. Chapter: All-Ceramic Restorations.
All reference sources for topic Dental Crowns.