Replacing Lost Teeth with Dental Implants

Essentially 100% of all humans will lose a permanent tooth during their lifetime. 

In early life, decay and growth problems are the cause for the loss. In mid life, gum disease takes its toll. In later life, abrasion and cracking occur because the enamel of the tooth becomes brittle. All of us will need some sort of replacement for a lost tooth. 

Having a missing tooth in the back part of our mouth can be troublesome from loss of chewing capacity. Losing an upper, front tooth not only takes away our ability to bite, but the cosmetic consequences can be devastating.  

The profession of Dentistry devotes its industry to the restoration of these lost teeth. Many years ago, dentists carved teeth from wood and ivory. Then, as materials became available, plastic, ceramic and metal were used to fabricate caps, bridges, and removable dentures. In today’s world, most any lost tooth can be replaced with an artificial tooth supported by a dental implant.

Dental Implant Technology 

A Dental Implant is an artificial tooth ROOT. It is the portion of an artificial tooth that fits into the gum and bone of the jaw, and it is made of the metal titanium. This same metal is used throughout the body with other implantable devices such as artificial joints. Titanium metal is strong, lightweight, corrosion resistant, and modifiable into various shapes. 

A dental implant looks curiously like a simple metal wood screw. It has threads on the outside so that it attaches quickly to the bone of the jaw to provide initial stability when placed by the surgeon. The interior of the dental implant is tapped with machine threads to allow various devices to screw into the top part of the implant. These devices on top of the implant can then be used to retain individual caps, bridgework, or removable dentures. 

The final stability of any dental implant comes through a microscopic growth of bone into the surface coating of the implant. The surface preparation has microscopic tunnels, nooks, crannies, and undercuts. Once placed in the jaw, and over a period of several months, the patient’s bone actually grows into the surface of the implant and mechanically locks the device into the jaw. 

The dental implant tooth is actually 3 pieces precisely fitted and stacked one upon the other. The bottom is the titanium metal implant proper, the middle that is screwed into the implant is the Prosthetic Abutment, and the top portion that everyone sees is the white Porcelain Dental Crown. 

A dental implant can be used in various configurations depending upon the patient’s needs. It can be support an individual crown or cap, a bridge of multiple caps, or it can be used to supply retention to a removable denture. 

Once teeth are lost from the jaw, the bone resorbs or melts away with time. The presence of a tooth root or dental implant will stop this melting process.

The Restorative Process 

The dental implant supported restorative process is a team effort. The team is composed of: 

• The Patient
• The Family Dentist
• The Implant Surgeon
• The Dental Laboratory Technician 

The process starts with a consultation between the patient and the family dentist. The patient expresses their desires, wants, and needs while the doctor presents treatment options and discusses the associated ramifications.  

The intended final restorative result is chosen, and the remainder of the process works backwards from that planned result.

Once the desired prosthetic result is identified, the implant surgeon is brought in to confirm the requirements needed for the supporting implant attached to the bone. The family dentist designs the above-the-gums result, and the implant surgeon builds the below-the-bone base. 

The surgeon’s role is one of a foundation sub-contractor. His job is to build the sturdiest system he can while identifying the strengths and weaknesses of the patient’s bone and gum tissue. The surgeon is tasked with placing the longest implant that the bone can accommodate while maintaining a diameter that is appropriate to the case. Much like a fencepost, a deeper and longer implant within the bone will withstand much greater lateral forces. The surgeon must also take into account the soft tissue gum and lip overlay so the prosthetic result looks and functions normally and readily allows good cleaning by the patient. 

Once the dental implants are in place and stable, the patient returns to the family dentist. Impressions or casts of the teeth and mouth are taken to register the location, size, architecture, and color of the intended prosthetic result as it functions against the teeth of the opposite dental arch. These registrations include the top portion of the dental implant that pokes through the gum tissue. Then, the Laboratory Technician is consulted to fabricate the appropriate dental prosthesis so that it looks and functions like the teeth that were lost. 

The Laboratory Technician delivers the prosthesis to the Family Dentist who fits, adjusts, and maintains the device.

The Surgical Planning 

The implant surgeon, in conjunction with the family dentist, uses 3 dimensional Computed Tomography (CT) X-ray Scanning and related software to precisely position the implants in a virtual manner. Oftentimes, the family dentist will make a mock-up of the prosthetic result that the patient will wear in the mouth while the CT scan is taken. This mock up is called a Scanning Prosthesis, and it makes placement of the implant much more precise. 

The Scanning Prosthesis may act as a surgical guide for the placement of the implants, but the greatest precision comes from a robotically milled guide fabricated on the software work-up. The software work-up is actually emailed to a facility that then uses it to direct the movements of a robotic machine. This precision surgical guide is then placed in the patient’s mouth during the surgical procedure and controls left-right, front-back, long axis, and vertical alignment of the individual implants

Bone and Gum Tissue Grafting 

The implant team may decide that implants simply must be placed in a position where there is an inadequate amount of bone or soft tissue (gum). In this instance, grafting is undertaken either as an individual first surgery before the implant is placed, or the grafting may be done concomitantly with the placement of the implants.  

Bone grafts are commonly employed when a multi-rooted tooth is removed and the area is to be restored with a single, wide-body implant. Taking out the multi-rooted tooth results in a larger defect in the bone, and inadequate bone coverage of the implant results. Another common area of grafting is the underside of the sinus cavity in the upper jaw. Lifting the sinus membrane and inserting a layer of bone graft allows much longer implants to be placed here. 

Traumatic loss of teeth or teeth that have been removed many years ago frequently results in an inadequate layer of gum tissue at the implant site. In this instance, soft tissue grafting is employed before, during, or after the placement of the implant.

The Implant Surgery 

Most patients elect to undergo surgery with a light general anesthetic given in the surgeon’s private office. Local anesthesia with numbing medicine is also given to supplement the general anesthetic. 

The gum tissue is opened to reveal the underlying bone. The surgical guide is inserted, and the location is prepared with precision tools and instruments to receive the planned implant of specific diameter and length. 

The outside threads on the implant give the implant an initial stability referred to as “seating torque.” The gum tissue is then sutured over the top of the implant so that it rests back into its original position. The implant is buried completely under the gum tissue and left for about 4 months. 

During the ensuing waiting period, the bone grows microscopically into the surface coating of the titanium metal implant. The implant must be kept very still during this process, and it is kept from chewing or “loading.” It is quite similar to cement setting, but it is a biologic process.

Second Stage 

After a sufficient waiting period (between 4 and 6 months), the gum tissue is re-entered using local anesthesia, but occasionally with general. The Healing Screw that is a small, flat screw in the top of the implant is removed. A Healing Abutment is placed in the machine-tapped inner channel of the implant. The Healing Abutment is a metal dome that pokes through the gums. Its purpose is to shape the gum tissue to form a dish shaped “nest” that will reside against the underside of the planned dental crown. This nest is necessary to make the dental cap look natural and to cover the junction of the implant and cap.

The Dental Restoration 

The round Healing Abutment is left in place for about two weeks and can be removed and replaced by the family dentist without any numbing medicine. There is no sensation when it is unscrewed and replaced with a Prosthetic Abutment that is cone shaped. 

The family dentist will take an impression of the abutment and consult with the Laboratory Technician in regard to shape, size, and color of the desired crown or cap. This is the final metal piece to which the white dental crown or cap is cemented.

Reliability and Maintenance 

There are many scientific studies that show that dental implants have greater than a 95% success rate over a 5 year period. However, dental implants can fail just like natural teeth fail. If a person loses natural teeth because of a specific process, then it follows that implant supported teeth can be lost from the same process. And by the same token, if dental implants are cared for with the same devoted attention as natural teeth, then they should last a lifetime. 

Natural teeth and implant-supported teeth are generally lost from a few common causes:

• Poor Oral Hygiene
• Destructive Grinding of the Teeth
• Tobacco Use. 

Dental implants must be kept clean the same way that natural teeth are cleaned, and oral hygiene should be periodically evaluated by dental professionals. Gum disease from poor oral hygiene causes the melting away of supportive bone to the teeth and implants. They will become loose and literally fall out if not kept clean. 

One unique circumstance of the titanium metal implants is that they do not decay the way that dental enamel does. Certain medications prescribed for medical diseases can cause the salivary glands to quit producing fluid and this results in dry mouth (Xerostomia). This dry mouth can be terribly destructive to natural teeth. Decay can develop between the teeth, around fillings, and under caps even though the patient works diligently to keep the teeth clean. Metal implants are not subject to this decay and find frequent use in patients suffering from dry mouth. 

Unconscious clenching and grinding of the teeth (Bruxism) can cause natural teeth to wear excessively, fracture, and literally split between the roots. Even in milder cases of Bruxism, the accumulation of destruction over a long period time can take its toll. Consequently, fractured teeth are frequently seen in the maturing population. If the Bruxism is especially strong, the same deleterious action can take place on the dental implant, and it can be lost. 

Tobacco causes so many harmful effects on the body, and the teeth suffer also. Bone loss (Periodontitis) even in clean teeth can occur, and the same process affects implants. In fact, it is generally understood that a 10% increase in the failure rate of implants occurs with tobacco use. 

When a dental implant does fail, it usually can be replaced. Some implants fail for no apparent reason in the early months after initial placement. In these situations, the implant can be removed, a two-month waiting period is allowed for healing, and a new, same-sized implant placed in the same location.