rate of success.
The consensus regarding dental implants within the international dental community can be summarized in Table 1.1. Whereas the order of the comments may vary with the individual clinician, most would agree that these comments are valid and pertinent.
Implants and the Edentulous Patient
Over 32 million people in the U.S. wear partial or CDs [11] and approximately 33% of these patients complain that their dentures fit poorly, tend to loosen or dislodge during activities such as chewing and laughing, and/or there is pain on mastication. Flat ridges and/or shallow palatal vaults add to denture retention and instability problems and most dentists are aware that the mandibular CD presents retention issues.
Table 1.1 Advantages of dental implants.
| Implant dentistry is the future of dentistry.There is copious scientific literature on dental implantology.The 95–97% success rate of dental implants makes them an extremely predictable treatment.There is an overwhelming need for tooth replacement and predictable treatment of failing teeth.Implant‐retained prosthetics are a very satisfactory solution to the growing prevalence of edentulism in our aging population. |
Limitations and/or restrictions on diet, especially which foods can or cannot be eaten, also play a major role in the decision to seek dental implants. It is likely that a significant percentage of those patients experiencing pain or discomfort on chewing will not use their dentures during eating. Due to the decreased mastication forces associated with dentures, edentulous patients have been found to consume less food and have lower intakes of protein, intrinsic and milk sugars, non‐starch polysaccharides (fibrous matter), calcium, non‐heme iron, niacin and vitamin C than dentate people [12]. These dietary deficiencies often have significant adverse effects on overall health and wellbeing, as well as their QoL.
Many patients will resort to utilizing denture adhesives to aid in retention. These adhesives may lead to further problems as they are extremely difficult to remove from the tissues. Impaired speech patterns as well as halitosis (oral malodor or “denture breath”) are frequent complaints among denture wearers, even when the fit of the denture is not a significant issue.
It follows from the above, that patients seek dental implant therapy for a number of reasons, including the following:
Function
Esthetics
Comfort
Confidence
Facial appearance
General dental practitioners can address these issues and assist the patient in achieving oral health and functionality lost through missing teeth.
There are two major implant treatment modalities for the edentulous patient:
1 Implant over‐dentures. Implant overdentures are removable appliances which are both implant and tissue‐borne prostheses. They utilize an abutment and a denture attachment for the retention (Fig. 1.3). These appliances solve several major problems with traditional dentures by allowing:Increased masticatory forcesIncreased retention to potentially eliminate the need for denture adhesivesRemoval of palatal coverage for patients who cannot tolerate the denture due to their gag reflexAn implant‐supported denture is a satisfactory and viable economic alternative to the traditional CD.Screw‐retained fixed implant bridges. Fixed implant bridges are implant‐borne prostheses which are not removable by the patient. They are manufactured in zirconia or in acrylic overlaying a chrome‐cobalt or titanium bar. These appliances give patients the greatest masticatory forces and are more appealing to most patients because they are fixed in place.
Implants for Single Crowns and Bridgework
As stated above, 178 million people in the U.S. are missing at least one tooth [11]. Before the use of dental implants, fixed partial dentures (bridges) or RPDs were utilized. One major problem with these treatment modalities is that fewer teeth are taking the load. For example, in the case of a four‐unit fixed bridge, only two teeth are carrying the load of the four teeth it restores because the pontics provide no functional support.
Figure 1.3 Implant‐supported overdenture.
Source: Courtesy of Zest Anchor.
The advantages for placing an implant and restoring it to replace a missing, free‐standing tooth are summarized in Table 1.2.
Table 1.2 Advantages of implants replacing individual teeth.
| No unnecessary preparation of adjacent teeth for a traditional bridge Long‐term prognosis better than for a traditional bridge [13, 14] Long‐term cost is less than for a traditional bridge Significantly better retention of prostheses, including RPD's In the authors' opinion, ease of dental hygiene is improved with implants as opposed to a traditional bridge Greater long‐term patient satisfaction |
Dentists are accustomed to replacing multiple missing teeth with a RPD. In fact, RPDs have been a viable treatment option for decades. While they serve a recognizable and useful purpose, they do require some skill and much experience in regard to their design and fabrication.
Despite their many advantages, which include relatively low cost, RPDs have some major drawbacks. In particular, they can lead to increased ridge resorption, especially with appliances fabricated with non‐metallic bases, i.e., what are commonly known as “flippers.”
Whereas RPDs with polymeric (usually acrylic) clasps are somewhat “kinder” to supporting teeth, metallic clasps and rests will commonly traumatize the clasped teeth over time, notably causing wear and abrasion. This destructive action is due to clasps riding up and down the anchor teeth due to flexure of the RPD during mastication or parafunctional activities. Poor fit and/or repetitive vertical (and lateral) movements due to cyclic loading will not only exacerbate wear and abrasion of the abutment teeth but increase ridge resorption.
Another problem with RPDs, especially those with polymeric bases and poorly‐fitting appliances, is that food particles may often be trapped beneath the denture. This can lead to mucosal irritation, periodontal problems and, possibly, to decay of the supporting teeth. Further, staining of the acrylic “gum work” of the RPD as well as odor necessitates repeated and careful cleaning of the RPD on at least a daily basis to ensure a hygienic appliance and absence of halitosis. Depending upon diet and beverage consumption as well as smoking, there is often the need for more frequent cleaning of the RPD. Failure to remove the RPD and clean teeth and RPD separately compromises effective hygiene of both teeth and RPD.
There are, of course, some disadvantages to the use of implants to replace multiple teeth, Table 1.3.
Table 1.3 Disadvantages of implants vs traditional bridgework and RPDs.
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