Mark T. Litterer, D.M.D
Aubrey H. Scher, D.M.D.

Implants

Dental Implants

Dental implants are an exciting new advance in dental care for our patients. Success rates exceed 95% in most situations. There are, however, factors that reduce the long-term success of this procedure.Dental Implants have been used to replace missing teeth for almost 25 years. This is a wonderful option for patients to replace missing teeth. A dental implant is the best way a dentist can replace an individual tooth. Implants are titanium posts that are placed in the bone to serve as the replacement for the root portion of a missing natural tooth. The implant is biocompatible with your jawbone. The final restoration is similar to a crown on a natural tooth, and is not removable. It feels and functions as a normal tooth. This ability to add a tooth where it is needed has changed the way dentistry is practiced.

Missing tooth to be replaced with implant Implant inserted and covered with crown

Implants can be used to hold single crowns, or multiple crowns and bridges. However, connecting natural teeth and implants with bridges is generally not advised.

Multiple implants placed in upper jaw with no natural teeth, and restored with non-removable, complete crown and bridge dentistry

In addition to holding crowns, implants can be used to support partial dentures and "overlay" dentures, where the appliance is supported by implants but can be removed.

Edentulous lower jaw

Two implants placed,which will secure a denture with O-rings

Two implants will support this denture with o-ring counter parts . This is a secure denture when seated.

BenefitsThere are many benefits to using dental implants.· When teeth are lost, ongoing shrinkage of the jawbone occurs, which can cause the face to look older. · This shrinkage can also make adequate fit of a partial or full denture difficult. Placing implants can slow or stop this process.· Dental implants look, feel, and function like natural teeth, and offer a tremendous improvement in comfort, speech, eating, and convenience over conventional partial and full dentures.

The advantages of an implant supported removable appliance include:

More secure retention and fit of appliance, improving function and comfort
Less stress on any remaining natural teeth holding the appliance
Reduction or elimination of bone shrinkage where implants placed

Implant Placement
Implant placement is surprisingly easy, and generally there is little more than "aspirin pain" post-operatively. This is because the bone that receives the implant has no nerve endings, and the only minor discomfort is the small incision in the gum. The implants are checked regularly after placement to follow healing. It takes 2-4 months for the implants to integrate (bond) with the jawbone, at which time the post is placed. The last phase is placement of the final crown or appliance.

Patient Selection
The ideal candidate for dental implants is in good general and oral health. For successful implant placement, there must be sufficient bone height and width to hold the implant.· The amount of bone available is determined by clinical exam, and by x-rays. If insufficient bone exists, we now have the ability to increase the amount of bone with ridge augmentation proceduresSmoking, while not a contraindication, is a risk factor. In the lower jaw there must also be sufficient bone available above the mandibular nerve, which runs within the jawbone.

In the upper arch, the proximity of the sinus may reduce the amount of bone available. Sinus lift procedures can add bone to the floor of the sinus, allowing for implant placement. In cases where there are questions about bone anatomy, a CAT scan may be utilized to provide needed details.

Risks of Implant Placement
As with any surgical procedure, there are risks involved with implants. The greatest single concern with implant placement is impingement on the mandibular nerve, which is found in the lower back jaw. Damaging this nerve can cause a permanent numbness of that side of the lower lip. By carefully evaluating the position of the nerve with x-rays or Simplant, the risk of injury is very small and seldom occurs.

Another complication of implant placement is infection. This is an unusual occurrence. We usually do not know why the implant fails, but it is thought it may be due to bacteria that were already present in the bone before the implant was placed. Fortunately most failed implants can be replaced with another implant, once the site has healed. The success rate of implants reported in the dental literature ranges from 92%-98%, depending on the study. Implants can successfully be placed in adults of any age, although certain health problems may contraindicate their use. Your dentist will determine if you are a candidate for dental implants after a careful review of your dental and medical history.

Implant Treatment Outline
There are several approaches that may be used in implant placement, depending on the patient's particular needs. Generally, an implant restoration consists of three phases: (1) placement of the implant itself, (2) following implant healing, insertion of a post or other fixture that emerges through the gum, and (3) seating the final crown or prosthesis. Below is an example of a typical treatment sequence for a common restoration, the single tooth replacement.Phase One (Diagnosis and Treatment Planning)

Study model
X-rays and CAT Scan
Careful planning and coordination with the restorative dentist
Presurgical consultatoin

Phase Two (Surgeon)


	Appointment 1

Examination and treatment planning

Appointment 2

-Placement of implant
-hole is prepared to recieve implant

-implant is seated and gum tissue is closed

Appointment 3 (10 - 14 days)

Sutures removed


	Appointment 4 (4 weeks)

Site examined to assure proper healing


	Appointment 5 (2 - 4 months)

Implant exposed, if submerged at the insertion appointment

Appointment 6 (1 - 3 weeks after exposure)

Study models taken that record exact location of implant

When the study models are poured they produce an exact replica of the patient's jaws, with the implant simulation in place. Using the models, the dentist orders the exact size of post or fixture that will be attached to the implant and used to hold the restoration (such as a crown). The surgeon or the restorative dentist may perform this step.

Phase Three (Restorative Dentist)
The restorative dentist can use the study models, with the post attached to the simulated implant, to analyze the case before the patient is seen. The post may be contoured to the desired shape on the models, so only minimal refinements are needed when seated in the mouth.


	Appointment 7

Post seated permanently in the implant, and shape refined
Temporary crown placed on post
(Final impressions for the crown may be taken at this appointment)

Appointment 8 (if needed)

Final impression for crown taken and sent to lab

Phase Four (Restorative Dentist)

Appointment 9

Final crown seated and occlusion (bite) refined

There can be a number of variations in treatment. Under ideal circumstances it may be possible to place the implant without requiring a second surgical procedure. In these cases a healing cap may be placed at the surgical appointment, negating the need for the secondary implant exposure surgery (Appointment 5). Conversely, surgery may reveal less bone than expected, and implant placement may be delayed while more bone is generated.

Single Tooth Implant - Clinical Case
Below is an example of a single tooth replacement, using an implant. The bone support was adequate for implant installation. The strategy for this patient was to replace the failing natural tooth with a dental implant. At the time of surgery, an index was obtained. This index accurately identifies the location of the implant relative to adjacent teeth. While the patient is healing, the restorative dentist makes a provisonal tooth to be inserted at the time of the second stage. Because the precise location of the implant is known, minimally invasive surgery can be performed. Access to the implant is achieved and the provisional restoration is placed. This enables the dentist to modify the shape and form consistent with patient satisfaction. When this is completed the dentist inserts the final restoration.Pre Operative view of upper right central incisor. Darkness along gumline indicates root resorption.X-ray view of upper right central incisor. Note how the tooth has dissolved away (resorption).Removal of upper right central incisor (post-extraction). Implant positioning guide inserted after bone preparation to receive implant.Implant installed in the position of upper right central incisor.Patient extracted tooth bonded to adjacent teeth for interim replacement.Implant has now been exposed after a defined healing period and a post has been inserted for the retention of a temporary crown.After a period of time of cosmetic refinement, the restorative dentist inserts the final crown.

Simplant (CAT Scan)

Traditional dental x-rays most often do not provide sufficient information on the shape and amount of bone to predict the prosthetic outcome of implant treatment. By using a barium-coated template, which depicts final prosthetic outcome, a precise determination of the final restoration can be determined. (published references) This allows the restorative dentist to have meaningful prosthetic input during all phases of treatment. In preparation for the CAT Scan x-ray, a plastic appliance is fabricated. The patient wears this appliance during the CAT Scan. This allows prosthetic information to be incorporated on the CAT Scan. Once the medical radiologist processes the scan, it is sent to the requesting doctor for interpretation and planning. The study can be analyzed on a computer using software program called Simplant. Many restorative doctors have incorporated this technology in their office. The jawbone can be viewed three dimensionally. It becomes easy to determine the height, width and density of the bone, and the location of the mandibular nerve and maxillary sinus. Surgical simulations can be done on the computer, so the exact size and ideal location for the implant is known. In essence, your treatment is completed on simulator pre-surgically. Recent computer technology breakthroughs enable a surgical guide to be electronically constructed to guide implant placement during surgery.