Implant Dentistry: Replacing Tooth Roots

Since the beginning of dentistry, practitioners have made attempts to develop replacement teeth to be placed into the jawbones. In the 1960s, Swedish researchers initiated the concept of modern implant dentistry, where small titanium cylinders are placed into the jawbone as a strong, sturdy foundation for artificial teeth. This experimental technique was highly criticized to begin with, but has developed to the point where it is now used commonly by dentists.

Before titanium screws became the most commonly used type of implant in modern dentistry, there were many variations of implant used, such as:

Blades

Rather than individual screws to replace each tooth root, metal blades with heads that protruded above the gums were implanted into the jawbone. While this technique is still used today, titanium cylinders or screws are much more commonly used.

Subperiosteal Implants

Unlike modern screw-like implants and implanted blades, subperiosteal implants are attached onto the jawbone, between the gums and the bone. Similarly to blade implants, this type of implant is still used, although screw or cylinder implants that are placed inside the jawbone are considerably more popular.

How well do implants work as a substitute for teeth?

When performed on mouths of healthy patients who do not neglect their oral health or smoke excessively, dental implants work exceptionally well as a substitute for natural teeth. In fact, implant-placed teeth work so well that their function rivals natural teeth, and in many cases, implants have allowed patients who were unable to wear traditional dentures to chew normally and appear normal.

The 2-Stage Implant Process

In most cases, implants only require one or two clinical sessions to complete:

1. The gum tissue of the area to be treated is opened up, and then the titanium screw or cylinder is implanted into the jawbone. As the treated area heals, a process called osseointegration takes place. This is where the bone cells regrow around the implant, ensuring that it stays firmly in place, and can take several months to fully heal.
2. During the second session, the dentist makes a small hole in the gum tissue to expose the implant. After a healing cap has been placed onto the implant for a short time, a head is placed on to the body of the implant. Once the gums have healed for a short time, the artificial tooth or teeth – which function just as well, or sometimes better than natural teeth – are placed onto the implant.

There are some occasions where only one session is needed to successfully place an implant. In such occasions, the placed dental implant is allowed to protrude through the gums into the mouth. It can then be restored during the same appointment or at a later time.

Not all dentists place implants

Implants are placed in two distinct stages – first, the surgical placement of the implant into the jawbone, and then second, the placement of the crown onto the implant. Because of this, only certain types of dentist with specific training can perform the surgical aspect of placing an implant. The first stage is usually performed by oral and maxillofacial surgeons, prosthodontists, periodontists, and highly skilled general dentists. If your general dentist does not perform the surgical aspect of this procedure, they will refer you to a specialist. If they are unable to place the implant itself, your general dentist will most likely be able to place the crown. However, if your general dentist has the training and skills, they will often be able to complete the entire procedure.

If implants are so good, why doesn’t everybody have them?

First of all, and most importantly, it is always better to keep your natural teeth wherever possible. Another point to consider is that implants are expensive, and purposely replacing your perfectly functioning natural teeth with implants would be an unnecessary expense. Also, due to the complex nature of implantology, the results of each procedure are often less predictable than would be desired. The required maintenance is also equal to that of natural teeth, so implants are not simply a ‘set-and-forget’ solution to avoiding oral hygiene as many people might hope.

However, in situations where implants are needed, there is no other tooth-replacement option that possesses the same amount of durability, practicality, cost-effectiveness as with dental implants.

What You Feel or See

Conditions, Signs and Symptoms Related to Dental Implants

1. None of Your Natural Teeth are Present

The condition of being without any of your natural teeth is called edentulous, and thanks to the use of fluoride, better nutritional intake, and improved oral care, the number of people suffering from this condition is decreasing. However, there are still millions of people the world over who are missing all of their teeth, and it is unfortunate that many of those are the least able to afford dental implants.

Some of the classic symptoms and signs associated with the loss of all teeth include:

Collapse of facial structure

When all teeth are missing, the facial muscles below the nose lose much of their support. Without this support, these muscles collapse into the resulting space which can lead to an aged appearance. As no teeth are present, the lower jaw can move much further towards the upper jaw before stopping and hitting any facial structures, and many edentulous people are unable to fully close their jaw.

Jawbone shrinkage

When there are no teeth in the jawbones, the bone quickly begins to shrink. Over time, the bone structure can shrink down to one third or less of the original size. In situations such as this, the jawbones become weak and much less able to support artificial dentures.

Reduced ability to eat

The majority of removable artificial dentures are able to perform well several years after teeth have been removed before bone shrinkage affects their efficiency. However, in most cases, it reaches a point where the lower jaw, and sometimes the upper jaw dentures cannot chew food as effectively as natural teeth. Without suitable dentures, edentulous persons are usually only able to consume liquids and very soft foods.

Inability to accommodate traditional dentures

The more the bones of the jaw deteriorate, the less able they are to hold removable dentures in place in the mouth. This often leads to lowered self esteem and reduced satisfaction with the mouth.

If all of your teeth are missing, the following options are usually available to you:

 

• Rebase or reline your existing dentures – this may be accomplished if your dentures are working well, but no longer fit as well as they once did.
• Place conventional complete dentures – you can obtain complete dentures without any surgical intervention.
• Surgically alter soft tissues in the mouth – this option can be used to provide increased bone support, allowing the addition of new conventional dentures.
• Have implants placed, then create a removable denture – after implants are placed, you can obtain a complete denture that can be removed each day for cleaning.
• Have implants placed, then create a fixed denture – once implants have been placed, you can have fixed dentures places that you cannot removed.
• Do nothing – if you choose to do nothing, all edentulous symptoms will remain and worsen until you are forced to seek professional assistance.

 

2. Some of your natural teeth are missing

People lose their teeth for many reasons – accidental trauma, tooth decay, diseases of the gums and bones, and many others. Of the several tooth-replacement options currently available, dental implants are one of the best for many reasons.

Some of the classic symptoms and signs associated with the loss of some of your natural teeth include:

Collapse of facial structure

Although less severe than with the loss of all teeth, losing several teeth contributes to a sunken facial appearance. Teeth next to the missing tooth or teeth can become misaligned and move into some unusual positions. Additionally, a smile with missing teeth is considered unacceptable in most societies.

Jawbone shrinkage

When one or more teeth are missing, the supporting bone begins to shrink and leaves a contour defect in that area.

Reduced ability to eat

A reduction in the ability to eat is directly relatable to the number of teeth that are missing. While chewing efficiency decreases significantly after several teeth are removed, the removal of small number of teeth does not result in a drastic loss of chewing ability. The most obvious impact of the loss of a few teeth is the appearance of the smile.

If you have numerous teeth missing, the following options are usually available to you:

 

• Conventional fixed partial denture (bridge) – a partial, non-removable denture can be fixed onto your existing teeth.
• Conventional removable partial denture – this type of denture rests on your existing teeth, and can be removed for cleaning.
• Place implants and create a removable partial denture – have implants placed into your jawbone, and then place a removable partial denture that rests on the implants and existing teeth.
• Place implants and create a fixed partial denture – place implants into your jawbone, and have fixed, non-removable partial dentures placed onto the implants, or attached to both the implants and existing teeth.
• Do nothing – by doing nothing, your existing teeth will continue to move. Your bite will usually collapse and worsen. This option is certainly not recommended for more than a very short period of time.

 

3. One of your natural teeth is missing

There are usually two possible outcomes after one tooth has been removed:

 

• The removed tooth creates an unsightly appearance – a smile with a missing tooth is generally considered as unacceptable in almost every society. This alone usually influences people to seek professional treatment. When a less visible back tooth is removed, patients are usually less inclined to seek treatment until the following changes have taken effect:
• Surrounding teeth begin to move and the bite begins to collapse rapidly – it can take only a matter of weeks for the bite to collapse and surrounding teeth to move towards the space once a tooth has been removed. The contacting areas around the existing teeth begin to open, which can cause food to get stuck, usually resulting in dental caries (decay).

 

The following options are available if you have one tooth missing:

 

• Conventional fixed bridge – a non-removable bridge is fixed to the teeth either side of the space.
• Removable partial denture – a partial denture that can be removed for cleaning fills the space of the missing tooth, allowing improved esthetics and nearly normal function.
• Placement of an implant and artificial crown – place an implant into the jawbone, and then fix a non-removable crown to the implant. This option provides the looks, strength, and functionality of natural teeth.

 

What Your Dentist Can Do to Replace Missing Teeth

Thankfully, there are many options available for replacing any teeth you may have missing or had removed. Implants with overlying artificial teeth can be broadly classified into these major categories:

1. Replacing all natural teeth when a patient has no remaining teeth
2. Partial replacement of a number of missing teeth using the remaining teeth to complete the normal number of teeth in the mouth
3. Replacing a single tooth

Artificial prosthesis (replacement tooth or teeth) can be created to be removed by the patient, or permanently fixed inside the mouth. There are certain conditions that allow all three of the above options to be attached to implants.

The types of treatments currently available for placing over implants include:

Implant-supported Complete Dentures (Removable)

The placement of removable complete dentures on to implants is one of the most acceptable and popular replacements for traditional complete dentures currently available. This treatment consists of prosthesis similar to standard dentures that are fixed with small spheres, bars with clips that fit over the implant, or other suitable attachments such as strong magnets. These removable dentures must be taken out for frequent cleaning of the dentures, implants, and the oral soft tissues.

Advantages of implant-supported removable complete dentures

Placement of implants and removable complete dentures provides good-to-excellent denture stability while chewing, and high retention of the dentures in the mouth. This option is one of the easiest to perform and cheapest alternatives for significantly improving the effectiveness of complete dentures. Removable complete dentures are one of the least-expensive implant-supported tooth replacement treatments, and are relatively simple to repair. As the tooth and gums are replaced, this option also offers fantastic esthetics.

Disadvantages of implant-supported removable complete dentures

As they are not permanently fixed into place like natural teeth, removable complete dentures must be taken out of the mouth several times per day for cleaning of the dentures, implants, and inside the mouth.  Because they need to be removed regularly for cleaning, there is an increased risk of damaging them though dropping or over-aggressive cleaning.

Risks of implant-supported removable complete dentures

The placement of implants is a surgical procedure, which in itself carries its own risks. However, once the implants have successfully integrated with the bone and the dentures made, the risks are low. While implants can very occasionally fail in service, they can usually be replaced if this occurs. It is uncommon for prosthesis to fail before they have been in service for many years, but if this does occur they can be easily replaced. An implant can be replaced if it fails, and removable complete dentures can be repaired or replaced.

Alternatives to implant-supported removable complete dentures

The following alternatives are currently available:

1. Construct new conventional dentures without the use of implants
2. Rebase or reline your current dentures without using implants
3. Surgically modify your mouth and construct conventional dentures without placing implants
4. Place implants and a fixed denture onto the implants. The denture can be removed by your dentist, but not by you.
5. Do nothing

Costs of implant-supported removable complete dentures

The cost of implant-free dentures is moderate. Adapting removable dentures to attach to implants using heads such as small spheres is relatively inexpensive, although modification to attach using a bar-and-clip or other attachment method is more complex and expensive. Compared to other alternatives, these options are the least expensive options for implant supported and retained prosthesis.

Result of Nontreatment

Choosing to do nothing will result in your condition remaining, and continued loss of bone and oral soft tissues until you’re forced to seek assistance.

Implant-supported Complete Dentures (Fixed)

For those without any remaining teeth, implant-supported fixed complete dentures are one of the best tooth-replacement options available. However, implants are not suitable or cannot be used in people who lack the necessary bone support, and this option if the most expensive of the available alternatives for patients with no remaining natural teeth.

Advantages of implant-supported fixed complete dentures

This tooth-replacement therapy looks, feels, and functions almost exactly like natural teeth. The prosthesis remains permanently in the mouth, and can only be removed by a dentist. Almost every single patient has been completely satisfied with this treatment when it is accomplished properly.

Disadvantages of implant-supported fixed complete dentures

When compared with other available tooth-replacement options, there are very few disadvantages of this type of treatment. However, the procedure is very complex, time consuming, and comes with a high price tag. The patient must also have regular follow-up appointments to ensure it is still functioning they way it should.

Risks of implant-supported fixed complete dentures

Other than the risks associated with many surgical procedures, there are very few risks to this type of treatment. The denture can break, requiring it to be repaired or replaced. Occasionally, one or more implants can become infected, requiring the affected implant to be removed and replaced, and the prosthesis remade. However, these risks are incredibly minimal.

Alternatives to implant-supported fixed complete dentures

Patients will all teeth missing have the following alternative options:

1. Construct new conventional dentures without placing implants
2. Rebase or reline your current dentures without placing implants
3. Surgically modify your mouth and construct conventional dentures without placing implants
4. Place implants and a self-removable implant-supported denture
5. Do nothing

Cost of implant-supported fixed complete dentures

Although this option is typically several times more expensive than the other alternatives, almost every patient that receives implant-supported fixed complete dentures feels the cost is more than justified by the result.

Result of Nontreatment

Doing nothing will result in continuing with the same condition, and you will begin or continue to lose bone and oral soft tissue structure until you are forced to seek treatment.

Implant-supported Partial Dentures (Removable)

When there are still some natural teeth present, implants can be placed in the spaces where the teeth are missing. Partial dentures can be attached to the implants alone, or to the implants and existing teeth.

Advantages of implant-supported removable partial dentures

This type of treatment costs less than attaching a fixed denture to implants, and usually provides improved appearance for the gum and tooth replacements than a fixed denture. Repairs are also more straightforward than with fixed prosthesis. If a fixed denture is prefered in the future, the same implants can be used.

Disadvantages of implant-supported removable partial dentures

The only disadvantage of this option is that because the denture can be removed by the patient, the chance of accidental damage or loss increases.

Risks of implant-supported removable partial dentures

Normal surgical risks aside, this option is relatively risk-free. However, the denture can wear out or beak. Very occasionally, an implant may fail resulting in the need for removal and replacement of the implant, or reconstruction of the denture.

Alternatives to implant-supported removable partial dentures

The following alternative options are currently available:

1. Have a new conventional removable partial denture made
2. If enough natural teeth are present, have a conventional fixed prosthesis made without placing implants
3. Rebase or reline your current removable partial denture without placing implants
4. Place implants and attach a fixed denture that can only be removed by your dentist
5. Do nothing

Cost of implant-supported removable partial dentures

This type of treatment costs less than implants with a fixed denture, but considerably more expensive than conventional non-implant-supported removable partial dentures.

Result of Nontreatment

Any existing natural teeth will begin or continue to move, the bite will continue collapsing, and ability to chew efficiently will remain reduced.

Implant-supported Partial Dentures (Fixed)

There are many variations of implant supported fixed partial dentures, and almost all of them are the most acceptable and successful in dentistry. These artificial replacement teeth are usually screwed or cemented onto the underlying implants, and their appearance and function is almost identical to that of natural teeth.

Advantages of implant-supported fixed partial dentures

These replacement teeth look, feel, and function just like natural teeth. They stay in place permanently (unless required to be removed by a dentist), and are cared for just like natural teeth.

Disadvantages of implant-supported fixed partial dentures

Implant-supported fixed partial dentures are much more expensive and difficult to fix than removable ones.

Risks of implant-supported fixed partial dentures

Implant placement is a surgical procedure, and carries its own risks. However, the tooth-replacement portion of this procedure is very low-risk. Repairs may be required if small pieces of material fractures from the prosthesis, and a fixed prosthesis usually needs to be replaced if an implant fails.

Alternatives to implant-supported fixed partial dentures

If enough natural teeth are present, the following alternatives are available:

1. Have a new partial removable denture made, without placing implants
2. Have a conventional fixed bridge made, without placing implants
3. Have implants placed and attach a removable partial denture supported by the implants, and existing teeth if necessary
4. Rebase or reline your current removable partial dentures
5. Do nothing

Cost of implant-supported fixed partial dentures

This type fixed implant-supported denture is more expensive than removable partial dentures placed on implants.

Result of Nontreatment

Any existing natural teeth will begin or continue to move, the bite will continue collapsing, and ability to chew efficiently will remain reduced.

Single Implant With Fixed Crown

This type of tooth replacement very closely matches all the characteristics of a natural tooth.

Advantages of a single implant with fixed crown

Remaining teeth either side of the missing tooth are not involved at all, and the replacement tooth looks, feels, and functions identically to a natural tooth.

Disadvantages of a single implant with fixed crown

A single implant-supported artificial crown is expensive, and the cost is usually equal to that of a fixed bridge attached to the two adjacent teeth. Other than the high cost, there are no other disadvantages.

Risks of a single implant with fixed crown

Other than the normal risks associated with surgical procedures, the risks of single implants with fixed crowns are relatively low. In the same way as natural teeth, an artificial crown can still be damaged accidentally. In very rare cases, the implant may fail resulting in the need to remove and replace the implant and crown.

Alternatives to a single implant with fixed crown

Patients with one missing tooth currently have the following available alternatives:

1. Conservative or conventional fixed bridge involving the adjacent teeth
2. Conventional metal or plastic removable partial denture to replace the missing tooth
3. Rebase, reline, or repair an existing removable partial denture
4. Do nothing

 

Cost of a single implant with fixed crown

The cost of placing an implant and crown to replace a single missing tooth can be up to three times that of placing a single crown on an existing tooth.

Result of Nontreatment

Remaining natural teeth will begin or continue to move, the bite will begin or continue to collapse, bone and oral soft tissue will deteriorate, and ability to chew efficiently will reduce.

While at the higher end of the scale of tooth replacement treatments, implant-supported prosthesis remain the best available option for replacing anywhere between a single tooth and all natural teeth. In many cases, implants are the only option that allow patient with all teeth missing to chew food efficiently, while providing an excellent alternative to patients with several teeth missing. As they have had many years of observation and clinical research, implants have become the go-to treatment for replacing missing teeth of any number. When implants and their attached prosthesis are properly placed and maintained, they are the most natural looking, feeling, and functioning alternative to natural teeth.