In a world filled with whitening toothpastes and drugstore whitening kits, it’s important to know that the most effective teeth whitening treatment still comes from your dentist. Not only do dentists have more powerful tools at our disposal, we are also experts on your smile, and can tell you whether teeth whitening is right for you and what kind of results to expect.
To understand how to whiten teeth as effectively as possible, let’s start with a little science.
If you look at teeth under a microscope, you can see that the hard outer layer, called enamel, is made up of a tightly packed crystal structure called rods. While this layer seems solid and smooth to the naked eye, it’s possible for the molecules that cause stains to get deep into the enamel by seeping between the rods. In order to remove stains, dentists use a chemical that can get down to where the stains are and break up them up using a chemical reaction.
The chemicals used in professional teeth whitening are hydrogen peroxide and carbamide peroxide (which breaks down into hydrogen peroxide in your mouth, so hydrogen peroxide is still the active ingredient). Hydrogen peroxide penetrates the teeth and causes a reaction called oxidation, which breaks down the stain compounds.
By the way, whitening toothpastes work by removing surface stains on teeth, not the ones under the surface. They do this by being more abrasive than other toothpastes, which is why your dentist may discourage you from using whitening toothpastes if you have complained of tooth sensitivity. More than anything, toothpastes are good for preventing stains, not removing them!
At-home teeth whitening products from the drugstore also contain carbamide or hydrogen peroxide, but in much lower concentrations. They also contain other ingredients for flavor and to help reduce the possibility of tooth sensitivity. While drugstore kits are much cheaper, because the bleaching agents in these kits are less potent, you can expect to see results in weeks as opposed to days (with a home kit from your dentist) or minutes (when you get your teeth bleached at the dentist).
Another reason that it’s a good idea to go to you dentist for whitening treatments is they can evaluate whether your teeth should even undergo whitening to begin with. Some people don’t realize that whitening only works on natural teeth. Fillings and crowns are made of artificial materials that look like teeth, and feel like teeth, but chemically speaking, they’re very different. Most restorations are made from ceramic, porcelain, or composite resin. These materials do not react the same way to bleaching chemicals as your natural tooth enamel does. If you have large fillings or crowns, a dentist can recommend alternatives to bleaching for improving the appearance of your smile.
The professional teeth whitening process starts with a consultation with your dentist. Not everyone is a good candidate for teeth whitening, which is why you want to talk to a dentist before you have it done. If you have large fillings or crowns (caps) on your front teeth, teeth bleaching is not a good idea. The chemicals will bleach your natural teeth but not your dental restorations (which are made from ceramic, porcelain or composite material), resulting in your teeth being different colors.
Teeth whitening is most effective on yellow discoloration, and can be less effective on brown or gray discolored teeth, especially when the discoloration is the result of exposure to tetracycline antibiotics while teeth are still developing (before age 8).
Next comes the actual whitening appointment. Once you’re comfortable in the chair, the dentist will insert a lip retractor into your mouth, which is just a plastic guide that moves your lips out of the way so your teeth are easy to access.
The dentist will then cover your gums around your front teeth with a gel and then harden it with a high-powered light. This is called a gingival barrier, and it protects your gums from the teeth bleaching chemicals during the whitening process. The dentist may also apply a compound to your teeth that will help prevent tooth sensitivity.
The actual whitening process involves the dentist applying a gel made of 15% to 35% hydrogen peroxide to your front teeth. Hydrogen peroxide can penetrate the porous outer layer of your teeth and break apart stain compounds using a chemical reaction called oxidation. Depending on the whitening system being used, the application of the whitening gel may be followed by applying a high-powered light that speeds up the whitening process.
Most systems involve multiple applications of the gel throughout the whitening session. The dentist will rinse off the gel and reapply a fresh coat as many times as necessary within the space of about 40 minutes. Once complete, the whitening procedure can achieve four to six shades of whitening after only one session. Some patients experience tooth or gum sensitivity after whitening, but this usually goes away within a day or two.
While the effects of teeth whitening can last quite a while (months to years), depending on diet and other habits (like smoking!), the stains on teeth will eventually return. Some dentists may recommend maintaining a freshly whitened smile with a professional home whitening kit. These kits include custom made trays to fit your teeth and tubes of whitening gel that has a lower concentration of bleaching agents than the in-office variety. The patient lines the trays with the gel and wears them for a few hours at a time each day or while sleeping.
When it comes to teeth whitening, you get what you pay for. While over-the-counter kits from the drugstore are cheap and offer the convenience of at-home bleaching without a visit to the dentist, they are slower and less effective than professional whitenings. And of course, without the supervision of a dentist, you don’t have the guidance you need to get the best results. If you want truly Hollywood-white teeth, invest in a professional teeth whitening administered by your dentist.
Most people get their dental insurance through their employer, who will choose it depending on what they expect the dental needs of their employees are. However, if you are self-employed, not working, or your employer doesn’t offer dental insurance, you can sign up for dental insurance as an individual. Whether you’re buying dental insurance for yourself or you’re the person at a company who’s in charge of this task, it’s important to understand some basics about how dental insurance works so you can choose the best plan.
Some may be surprised to hear this, but dental insurance doesn’t really resemble insurance in the traditional sense (a payment to cover the cost of a loss). Most plans operate more like a cost-savings membership than an insurance plan. While your auto insurance will pay to repair your car if you have an accident, if one of your tooth gets damaged, your dental insurance will not pay for all of it. The cost of repairing the tooth will be split between you and the insurance company, and the portion you pay is determined by the plan you chose.
Many dental insurance plans include coverage for some services but not others. For example one plan may cover tooth sealants but not braces, compared to another that covers braces but not sealants. The fact that a dental plan doesn’t cover a certain service doesn’t mean that this treatment isn’t necessary or that you should hesitate to get a treatment that your dentist has recommended.
Some dental plans will also offer an alternate lower cost version of a treatment for a given dental program. For example, if you need a crown, your dental insurance may suggest a lower cost amalgam (metal) crown instead of a composite (tooth-colored) crown. This doesn’t mean that the composite option is “extra” or less recommended, it simply means that the insurance company is trying to reduce how much they have to pay. You should always select the treatment that is both recommended by your dentist and fits your goals for the outcome of treatment. For example, if you’d rather have a composite crown that looks like a natural tooth than a metal one that stands out, you should get the composite, even though the insurance company will not help you pay for as much of it.
It’s a good idea to try to find a plan that emphasizes preventive care by paying to cover these services at 100%. That means that routine preventive care such as teeth cleanings, exams and x-rays won’t cost you anything out-of-pocket. Preventive care will help save you money in the long run. Problems can be prevented entirely (e.g. removing tartar from teeth to prevent decay) or caught earlier when they’re easier and cheaper to treat (e.g. filling a cavity when it’s still really small).
There are three major types of dental insurance plans, and it can be helpful to know the differences.
With a Preferred Provider Organizations (PPO) plan, patients select a dentist from a list of participating providers. These dentists have contracted with the insurance company to offer a discount on their fees. While most PPO plans allow patients to go to a dentist who is not a preferred provider, these patients will usually pay a slightly higher co-pay at a non-participating dentist (for example: 80% coverage on a crown procedure at a non-provider vs. 90% at a contracted provider).
A DHMO plan (sometimes just called an HMO) contracts with dentists & pays them a fixed amount (usually monthly) per family or individual enrolled in the plan, regardless of whether they go to the dentist or get treatments. In exchange, the dentist doesn’t charge the patients for certain types of treatment. In theory, these plans are designed to reward dentists who keep patients in good dental health, because it reduces costs for everyone. However, the result is often a more limited choice of which dentists you can go to.
Direct Reimbursement plans do exactly what their name implies: the insurance company reimburses patients for the dollars spent on dental care. The biggest benefit of this is that patients get total freedom to choose a dentist, because the dentist is removed from the insurance equation. However, it does mean that the patient will have to pay the whole cost of their payment up front, then wait for a check to be sent after they file a claim. If paying for treatment out-of-pocket immediately is a hardship for a patient, many dentists now offer payment plans or financing to help spread the cost of treatment out over time.
Teeth whitening is one of the quickest & least invasive ways to make a huge difference in the appearance of your smile. Most dentists offer either in-office teeth whitening, take-home teeth whitening kits, or both. The effectiveness of these whitening methods varies slightly, but the way they work is generally the same.
While many people refer to teeth whitening as bleaching, it’s important to know that the dentist doesn’t use the same chemical to whiten your teeth that you use to whiten your laundry! Laundry bleach is a chemical called sodium hypochlorite that smells like chlorine, & it can be poisonous if ingested, so we don’t want it anywhere near your mouth! For teeth bleaching, two chemicals are commonly used: hydrogen peroxide & carbamide peroxide.
Even though the hard outer surface of your teeth, called enamel, seems solid, on a microscopic level, it is actually porous. Stains & discoloration on your teeth appear when compounds from the foods you eat (or from smoking) penetrate this porous enamel layer & accumulate there. Teeth bleaching works when hydrogen peroxide creates a chemical reaction that breaks apart the staining compounds.
During an in-office teeth cleaning, the dentist will first clean your teeth then apply a gel that contains 10 to 35 percent hydrogen peroxide. Sometimes a high powered light is then used to help speed up the chemical reaction. After leaving it on for several minutes, the dentist will remove the bleaching gel, then re-apply it. The entire whitening procedure usually takes about 45 minutes to an hour.
For at-home teeth bleaching, your dentist will take an impression of your teeth & creates soft dental trays. These trays are then filled with a thin layer of gel that contains 10 to 20 percent carbamide peroxide. (Carbamide peroxide breaks down into hydrogen peroxide & urea in the mouth, so the active bleaching agent in at-home kits is still hydrogen peroxide.) At-home bleaching trays are worn for a few hours during the day or while sleeping. Because they are less powerful, at-home systems take longer to achieve the same whitening effects as in-office systems.
Teeth bleaching is not a good solution for everyone. Because teeth bleaching is designed to treat stains on natural tooth enamel, patients who have tooth colored restorations (i.e. fillings or crowns) or veneers should not get their teeth whitened. Whitening compounds do not work on the ceramic or porcelain composites these restorations are made from, so the result is that teeth color may become mismatched. Teeth bleaching will also not work well on tooth discoloration that is the result of changes inside the tooth, below the enamel, such as grayish teeth caused by certain medications. For this reason, we always recommend that teeth whitening, whether at home or in-office, be performed under the supervision of your dentist.
Have you ever looked at a celebrity smile & wished your smile could be equally perfect. Well, it’s no big secret among dentists that most Hollywood stars were not born with perfect teeth. For many celebrities, their Hollywood smiles are achieved with the help of cosmetic dentistry, particularly porcelain veneers.
Porcelain veneers are a great option if you want to improve the appearance of your smile efficiently & affordably. Compared to other cosmetic dentistry procedures, such as dental implants, crowns or even orthodontic braces, veneers are less invasive & often less expensive. Because veneers are less complex than these other options, they are also one of the easiest options for a smile makeover.
Veneers can be used to repair & beautify cracked or stained teeth, lengthen short teeth & fix gaps between teeth. Veneers are shells made of tooth-colored porcelain that fit over the front of your teeth. They are most commonly used on the front teeth of the upper jaw, which tend to show the most when someone smiles, laughs or speaks.
The entire veneers procedure usually involves several visits. The first visit usually involves a discussion with your dentist about the goals for the design of your new smile. At this visit the dentist may also take an impression (i.e. a mold) & x-rays of your teeth.
At the second appointment, the dentist will prepare your teeth for veneers. The dentist will remove a small amount of the enamel on the surface of each tooth that is going to be covered. This helps the veneers fit properly & securely, however it also means that the veneers procedure is irreversible. The resulting transformation of your smile is well worth it! In the meantime before your next appointment, the dentist may attach temporary veneers to protect your teeth & make them look better.
The veneers are then created by a dental lab technician, based on a model of your smile made from the mold. The color of porcelain veneers is carefully selected to look natural with your existing teeth, though of course they may be whiter in order to improve the appearance of your smile. Porcelain is a great material for veneers because it is durable & its texture is very similar to that of teeth, including how it absorbs & reflects light.
At your last appointment, the dentist will ensure your veneers are ready to fit your teeth, trimming them or making color adjustments as necessary. Veneers are affixed to your teeth using a special dental cement, the color of which can be adjusted to help make sure your veneers look natural. Once the veneer is in place over your tooth, the dentist uses a special light to harden the cement, so it bonds your veneer to your tooth very quickly.
You should care for veneers just as you would care for your natural teeth, by brushing, flossing & visiting the dentist regularly for teeth cleanings. Though porcelain is stain resistant, it’s still a good idea to avoid foods that could stain your teeth, such as coffee, tea, or red wine, as this will help make sure your natural teeth continue to match your veneers.
The goal of modern dentistry is for each & every patient to keep all their teeth for their entire lifetime. As dental health awareness & dental technology have advanced over the last half century, we now see fewer older people who are missing all their teeth (a condition dentists call edentulism). Still, we find that people may loose a tooth or a few & not think much of it. The reality is that a missing tooth is far more than just a gap in your smile: it can have serious oral health & psychological effects down the line.
Bones are similar to muscles in that if you don’t stimulate them, they will start to atrophy. The bones in your jaws are stimulated when the force of biting & chewing travels down the root of your teeth into the bone. When you lose even a single tooth, the bone under where the tooth used to be starts to weaken & decrease in density. If you are missing all the teeth on your upper or lower jaw, this effect is even more pronounced, & can lead to the face having a sunken & shortened appearance that makes a person look much older.
Patients who have lost teeth also experience negative effects on their health & quality of life. Missing teeth can make it hard for people to eat healthy foods that might be difficult to chew, such as nuts, vegetables & meats. As a result, many patients with missing teeth also suffer from poor nutrition. Missing teeth can also have social consequences, as patients who are self conscious about their appearance or eating ability may avoid social activities that they once enjoyed.
If you are missing teeth it’s very important that you look into your options for tooth replacement as soon as possible. The longer you wait to replace a tooth, the worse your problems with bone loss & other consequences will be.
Dental implants are by far the best option for replacing teeth. A major reason for this is they replace both the tooth root & the crown. The fact that the replacement tooth is imbedded in the bone helps prevent further bone loss. The implant is an artificial tooth root that is anchored in the bone. The crown is a porcelain or ceramic tooth that is then attached to the metal implant using dental cement. Essentially, the only drawback to dental implants is the healing time, which can be as long as three months. But the result is permanent teeth that will last the rest of your life & be as functional as if you never lost your natural teeth. Plus, unlike other tooth restoration options, implants don’t ever have to be replaced or adjusted, so you only have to pay for them once.
Bridges are replacement teeth that are held in place by attaching to neighboring healthy teeth. While traditionally bridges have been made from gold, ceramic, or alloys, today the preferred kind of bridge is made entirely of ceramic. This provides the most natural-looking result. A ceramic bridge consists of a false tooth with hollow tooth crowns on either side. These hollow crowns are then cemented to nearby healthy teeth that have been reshaped & the false tooth in the middle fills the gap left by your missing tooth.
Bridges can help prevent bone loss in your jaw & also keep your remaining teeth from shifting into the gap, which can misalign your bite, make chewing difficult & even affect your appearance. While bridges are durable & long-lasting, most of the time they do need to be replaced eventually. Bridges are also a less desirable option than implants because they involve taking structure away from healthy teeth in order to attach the bridge, so the loss of one tooth ends up affecting several teeth.
Dentures are dental appliance that replace an entire arch of teeth (i.e. all the teeth on your upper jaw or lower jaw). Dentures consist of a plate that holds false teeth & gums that are held in place by fitting over your gums & the power of suction. Dentures are usually made of a durable resin material that is colored to look like your own natural teeth. Partials are used for patients who are missing a few, but not all, of the teeth in an arch. They consist of a plate that fits against the roof of the mouth, false teeth, & clips that attach to existing teeth to hold the partial in place.
While dentures & partials will restore the appearance of your smile & some of its function, they do not help prevent bone loss due to missing teeth. Even if you wear dentures the bones of your jaw will continue to diminish & change shape. As a result, you may need to have your dentures adjusted or replaced, as the original bone structure they were designed for will have changed. This is why, despite having a lower upfront cost, dentures can end up costing more than dental implants in the long run.
If you are missing teeth or know you are at risk of losing teeth, please don’t hesitate to talk to us about your options.
There is more than one type of dental procedure that may be casually referred to as a cleaning. For example, there is a regular cleaning & then there is what is referred to a deep cleaning. It’s important to understand that there is a big difference between these procedures & implications that each of these procedures have when it comes to your oral health.
A regular teeth cleaning, which is called prophylaxis by dental professionals, is what most people think of when they think of going to the dentist for a checkup. Prophylaxis involves removing plaque, calculus & stains from teeth. (Plaque is a sticky substance that builds up on teeth as a byproduct of bacteria feasting on the food you eat. Calculus, also known as tartar, occurs when plaque & minerals in your mouth harden.) A dental hygienist or a dentist uses a specialized cleaning device, called an ultrasonic scaler, to remove plaque & calculus. This cleaning occurs only on the visible part of the tooth, known as a the crown.
Regular teeth cleaning is only recommended for patients who have generally good oral health & do not suffer from bone loss or gum problems (bleeding, recession, infection, etc.)
Root planing is a procedure that involves removing tartar, bacteria, toxic deposits from the root of a tooth, all the way down to where gum & bone meet. While it is sometimes casually referred to as a “deep cleaning”, you should know that this treatment is quite different from prophylaxis. This procedure is required as a treatment for periodontal disease or periodontitis (commonly called gum disease, though it also affects the bone).
Many people can have periodontal disease & not even know it. Symptoms of the disease include bleeding gums, bad breath, teeth that look longer due to recessed gums, & swollen or red gums. However, many people do not notice any symptoms at all. That’s why it may come as a surprise when your dentist recommends scaling & root planing instead of a regular cleaning. It’s important to understand that this procedure is vital to getting periodontal disease under control & avoid future tooth loss, though other procedures including surgery may be required to treat the disease.
Once you have been diagnosed with periodontal disease & have undergone scaling & root planing, periodontal maintenance is what you can think of as taking the place of prophylaxis in your dental care routine. Rather than just addressing the just crowns of your teeth as in prophylaxis, periodontal maintenance also cares for your tooth roots, gums & bone. In other words, think of it as cleaning & maintenance for the tissues affected by your periodontal disease. The frequency of your periodontal maintenance appointments depends on your individual oral health condition & will be determined by your dentist.
Tooth extraction is when a tooth is removed from it’s place in the gum & bone of your jaw. Compared to many dental procedures, tooth extraction can sound scary, especially when it’s referred to as “oral surgery”. However, we believe that understanding the reasons that an extraction is necessary will ease your mind if you’ve been told you need a tooth removed.
Dentists will alway try a conservative approach first when trying to repair a tooth that is damaged. However, if the damage is too severe for the usual solutions such as a crown or a filling, the dentist may decide to remove the tooth completely. Teeth sometimes shift into the place where the removed tooth used to be, which can cause problems with your bite. For this reason (& your own comfort) we may recommend putting a bridge, partial denture or dental implant in the space where the missing tooth was.
Tooth extraction can also be a part of orthodontic (or braces) treatment. When teeth are too large for the mouth & are causing problems, teeth may need to removed in order for orthodontic treatment to be completed. The most common reason for tooth extraction in braces treatment is the alleviate crowding, though there are other conditions that may warrant the removal of teeth (such as overbite). Usually teeth are removed symmetrically, so the same 2 teeth in each jaw are removed in order to keep the bite balanced, so a total of 4 teeth would be removed. While tooth extraction for the sake of braces may seem like an extreme choice, but in some cases it is an alternative to more serious surgery to re-align the jaw.
Wisdom teeth are an extra set of adult molars that usually come in when patients are in their late teens or early 20s. Not everyone’s wisdom teeth cause problems, but it is common for them to be impacted, meaning they’ve come in at a funny angle or have failed to come in at all, & trapped under the gum pressing against other teeth. In some cases, wisdom teeth can become infected or cause abscesses, pain or swelling. Wisdom teeth removal is usually recommended on wisdom teeth that are impacted or have otherwise started to cause problems.
Sometimes a dentist will recommend tooth extraction of baby teeth (also known as primary teeth or “milk” teeth) that have not been lost in a timely fashion. For example, if your dentist sees that your child still has a baby tooth that most children their age would have lost years ago they may recommend extracting it. The reason for such extractions is usually to ensure that permanent adult teeth come in (or erupt) in the right position.
It’s also important that you understand that dentists never take the extraction of a tooth lightly. Our first choice is always conservative treatment (i.e. “conserving” as many teeth in your mouth as possible), but sometimes health or developmental considerations make keeping a tooth inadvisable. No matter the reason, if we’ve recommended tooth extraction as part of your treatment, we will go over the details of what to expect both during & after the procedure, & what the resulting benefit to your health will be.
You’re used to going to the dentist & just seeing the doctor, the hygienist & maybe a dental assistant. But now you’ve been told you need to see a periodontist too. Now you’re thinking, “Perio-what?”
If you’ve never heard the word periodontist, don’t worry. To put it plainly, a periodontist is a dentist who specializes in caring for your gums & the other supporting tissues of your mouth. “Peri-” means “around” & “odont” means “tooth”. Periodontal means having to do with the tissues around your teeth & periodontitis means infection of the tissues around your teeth.
Dentist usually refer patients to a periodontist because they have periodontal disease, also known as gum disease. While general dentists are also qualified to treat periodontal disease, periodontists can offer more specialized care and attention, just like an orthodontist can offer more specialized braces options that most general dentists.
Dentists may also refer you to a periodontist if you have health factors that put you at higher risk of periodontal disease & it’s complications. Examples of such risk factors are pregnancy, diabetes, heart disease, chronic respiratory disease or having recently undergone cancer treatment or organ replacement surgery.
While a dentist may choose to treat your periodontal disease at their own practice at first, they may choose to refer you to a periodontist if they feel a specialist will be able to offer you a more successful outcome. By the way, when we say a more successful outcome when it comes to periodontal disease, we generally mean you’ll end up keeping most of your teeth.
As you may have realized from the explanation about terminology above, periodontal disease is a disease of the tissues around your mouth. Specifically this means your gums & the bone of your jaws, which are what hold your teeth in your mouth. If these both become diseased & weakened, your teeth can fall out. Having periodontal treatment (often called periodontal maintenance) from either a periodontist or your general dentist reduces the chance you will lose a tooth.
We know that some periodontal patients view going to see a periodontist for their treatment as an inconvenience, so we will do our best to pair you with a specialist who’s hours fit your busy schedule. However, if you find that you just can’t make the time to go to the periodontist, we’d much rather you see us for your periodontal maintenance rather than not doing it at all.
If you have any questions about your referral to a periodontist or your diagnosis of periodontal disease, please contact us!
Dental crowns, or caps, are one of the most common restorative dental procedures that dentists perform. If you’ve been told you need a crown, there’s no reason to worry. Dental crowns allow us to restore your smile both functionally & aesthetically, & modern techniques mean we can complete the procedure faster than in the past.
First, let’s review the anatomy of a tooth. Each tooth comprises two parts: a crown, which is the visible part outside your gums, & a root or roots, which are embedded in your gums & jaw bone. Sometimes when you hear a dentist say the word crown, they’re referring to the visible part of your tooth, & other times they may be talking about an artificial crown that is used to repair a tooth.
Most of the time, when your tooth is damaged by decay or an accident, a filling or bonding is all that you’ll need to restore your tooth. However, sometimes tooth decay or damage is extensive enough that the dentist will recommend replacing the entire outer structure of your tooth. This restoration is what we call a crown (also commonly called a cap).
The dentist will start by removing some of the outer structure of your tooth. Then, they will attach the crown using a permanent adhesive cement. This crown will have been made ahead of time to match the shape, size & even the color of your tooth.
In the past, the only option for dental crowns was a metal restoration, made from precious metal, semi-precious metal, or a metal alloy. These days, however, dental materials technology has advanced to the point that there are several kinds of tooth-colored crown materials available. Most of these crown materials are some kind of porcelain, which can be made to resemble tooth enamel both in color, texture & the way it reflects light.
Commonly, these modern tooth-colored crowns will be manufactured by a dental laboratory that your dentist works closely with. The dentist will match the crown to the color of your tooth using a guide, then pass this information on to a laboratory technician, who handcrafts your custom crown.
Alternatively, modern 3-D scanning & milling technology has allowed dentists to bring this process in-office. Instead of sending information to a lab & having them send back a custom crown, computerized scanner & computer-controlled milling machines located right in the office can carry out this process. The use of this state-of-the-art technology means that dental crowns can be created & placed in your mouth much faster than ever before.
If you’ve been told you need a dental crown, keep in mind that because there are many types of materials available to make crowns, you can have some control over the price of your tooth restoration. However, we must emphasize that your dentist will always encourage an option that returns your tooth to the function & appearance of your original tooth. When cared for using a standard dental hygiene routine of brushing, flossing & 6-month checkups, a crown is expected to last a lifetime.