Implant Prosthodontics

These "before" and "after" photographs of our patients illustrate implant- related  procedures performed in our practice.                   

 What is a dental implant?

A dental implant is a screw-shaped cylinder of titanium metal.  A dental implant is placed into the jawbone in order to serve as a substitute for the root of a tooth. Above is an x-ray of three dental implants. The screw-type threads help to anchor the implant in the bone. The body grows new bone next to a newly-placed implant in a process called osseointegration.

Implants do not replace the visible part of a tooth-- only the root. The teeth must be made in a separate procedure. The replacement teeth are either screwed directly onto the implants , or are screwed or cemented onto an intermediate component called an "abutment." 

Benefits of dental implants

One of the major applications of dental implants is for people who are missing all their teeth.  Dental implants prevent the gradual shrinking of the gums and jawbone that occurs following the loss of teeth.  This gradual gum and bone shrinkage makes it increasingly difficult to wear removable dentures.

Fixed Replacements (not removable by the patient)

This lower tooth replacement (below) is entirely supported by dental implants, and does not touch the gums.  It was one of the first designs used for tooth replacement.  Now, the same type of tooth replacement can be designed so that the metal posts are not showing.

This case was completed in 1989.  The important thing to realize is that this patient could not wear a typical denture because his lower gums had resorbed ("melted" away) from many years of denture use.  This approach, developed in Sweden, was considered to be a major advance in addressing this type of handicap.  The patient is using  a conventional denture without implants to replace the upper teeth. 

A similar approach, except that it replaces upper teeth, is pictured below.  You can see the silver-colored ends of the seven implants used to support and retain this type of tooth replacement.

                                             

                                              

Using Ceramic materials

The tooth replacements you have seen so far were constructed with teeth made from high-quality acrylic resin.  However, in some situations, it is better to use ceramic (porcelain) materials.  Porcelain is more wear-resistant than acrylic, and according to some, can produce better cosmetic results.  However, it can be more difficult to repair if fractures occur. 

 Below, five of the six upper front teeth are porcelain crowns supported by dental implants underneath.  Note that the teeth appear to emerge from the gums just as a natural tooth would.  Accurate implant placement is critical to achieve this kind of result.  

  

Removable Replacements (removable by the patient) 

For people missing all of their lower lower teeth, a removable tooth replacement retained by two dental implants in the front of the jaw has been shown to be more comfortable, and to enable better chewing, than a denture without implants. 

                                            

As an alternative to the individual snap-type attachments pictured above, several types of gold bars may be used to join the implants together, providing a place for the denture to clip onto.  However today, the individual types of attachments are more common. 

Current Trends in Dental Implant Therapy

Immediate function

In the past, a patient had to wait from 3 to 6 months after implant surgery before their dentist could start constructing teeth. Now, for many patients, temporary teeth can be placed on the implants the day of implant surgery. Since current advertising practices frequently do not make this clear, it is worth emphasizing that these are temporary tooth replacements.  These temporary tooth replacements are made of a durable plastic material, and may break if they are worn longer than the recommended period of time. 

Number and distribution of implants

In the past, it was felt that five implants were needed to replace all the lower teeth, and that six to eight implants were needed to replace all the upper teeth. While these same guidelines are used for certain patients for specific reasons, fewer implants have become the new standard. 

A number of years ago, we began using four implants to support a lower tooth replacement.  Here is one example of a patient treated in the year 2000. At left, four dental implants are in position.  At right, a temporary bridge is seen, placed in the mouth one day after implant surgery.  At center, below, the final tooth replacement made from ceramic materials.

                                     

 

As this field has developed, it has become commonplace to use only four implants to support a full set of upper or lower teeth, provided that the implants are widely-distributed. Below, left, is pictured a lower tooth replacement supported by only four implants.  Below, right, is an upper replacement using 4 widely-distributed implants. 

                                                     

 

Below, you can more clearly see that the implants are distributed widely, like the legs of a table.