Criteria of Success of Implants and Maintenance of Implants

After going through the previous units, you would have gained insight into the treatment planning; surgical procedures followed by the prosthetic restoration of implant supported prostheses. However, following the treatment it is vital to judge whether the whole process has been a success or a failure and if any further management is warranted. Also you would have realized that implant supported prostheses have to be maintained very well by the patient to ensure their lasting success, as the oral cavity is teeming with microorganisms and dental implants (by virtue of having an intra oral communication along with the complex biomechanics involved) are not bereft of danger of failure if neglected.

Dental implants are becoming more predictable. Success rates have been reported to be 85 to 90 per cent over 5-10 years as maxilla and 90-95 percent for mandible.Advances in surgical procedures, such as maxillary sinus lifts, lateral inferior alveolar  nerve placement, and guided bone regeneration (GBR) allow the practitioner to place implants in patients who would not have received this treatment option a few years ago.When these figures for the success rates are mentioned, it is imperative for us to understand what defines success in implantology.One aspect that we should always remember and the importance of which can never be over-emphasized, is that there are inherent differences in the nature of implants and natural teeth. The absence of the periodontal ligament and the presence of osseointegration instead of the gomphosis joint leads to the difference in movementunder axial and lateral loads, reduced proprioception in implants and difference in response to overload. The transmucosal area or the soft tissue around the implant is also very different from the gingiva and connective tissue around the teeth. The absence of cementum in implants leads to the presence of parallel collagen bundles which are not inserted into the implants surface and therefore a susceptible soft tissue barrier between the periimplant bone and the oral environment.

The ideal clinical conditions of teeth which we know already include:

• the absence of pain.
• less than 0.1 mm initial horizontal mobility under lateral forces of less than 100 g.
• less than 0.15 secondary mobility with lateral forces of 500 g.
• absence of observed vertical mobility.
• periodontal probing depths of less than 2.5 mm.
• radiographic crestal bone height 1.5 to 2 mm below the cemento-enamel junction.
• intact lamina dura.
• no bleeding on probing.
• no exudates.
• absence of recession and furcation involvement in multirooted teeth.
• The success criteria for implants will be discussed next.