In the early decades of the twentieth century, it was commonplace for people to have all their teeth extracted and replaced by dentures on the principle that “If you have all your teeth extracted, you will no longer have any problems with them.” Whereas the extracted teeth are now surgical scrap and can no longer present problems for the patient, the dental profession is aware that edentulism presents a host of oral and systemic problems and does not cure or prevent oral disease. In fact, the opposite is usually the case.

Unfortunately, whereas replacing missing or failing dentition with implants may provide an immediate solution to complete or partial edentulism, many patients do not appreciate that continuing care is mandatory for the health and longevity of implants. In fact, it is a reasonable assertion that if the implant patient had paid as much attention to oral hygiene, they might still be dentate.

There is no question that oral hygiene procedures with dental implants can be tedious, but it is critical to long‐term oral health and survival of the implant, and both the patient and the dental professional must exercise considerable effort to ensure the success and longevity of the implant.

Preventing Implant Failures

Implant dentistry has possibly become the most important treatment regimen in restorative dentistry because of the extremely high success rates of long‐term dental implant survival and their restorations. Consequently, increasing numbers of patients select dental implants as a treatment option.

However, the dental team can be presented with challenges in situations when patients are reluctant to undertake even basic oral hygiene procedures. Part of the challenge is that the focus of implant dentistry has changed from simply achieving osseointegration, which is now highly predictable, to the long‐term maintenance of the health of the peri‐implant hard and soft tissues. This requires appropriate professional care, patient cooperation, and effective home care. Thus, in order to ensure a successful outcome for an implant and its restoration, patients must accept the responsibility of being co‐therapists in maintenance therapy and, consequently, the dental team must screen potential implant patients to ensure that these are achievable goals. Typically, diagnosis and treatment planning based on a risk–benefit analysis should be performed after a thorough medical, dental, head‐and‐neck, psychological and radiographic examination as well as a temporomandibular joint health evaluation.

Failure of implants was discussed in Chapter 15 and it was indicated that the predominant causes of failures are infection, peri‐implantitis, inadequate or failure of initial osseointegration and, ultimately, loss of osseointegration, see Table 17.1. Two of these causes are related to oral hygiene while the last is predominantly caused by masticatory stresses and bruxism. The effect of unbalanced malocclusion on implants is discussed later in this chapter.

Many of the factors possibly contributing to implant failure have been discussed in previous chapters.

Indicators of Implant Problems

There is a steadily growing literature on the monitoring of the stability and osseointegration of dental implants and, increasingly, electronic and other non‐invasive technologies are being recommended for this important task [1–6]. However, possibly the best indicator for the diagnosis and/or prediction of implant failure is the presence of mobility. In contrast to a natural tooth with a periodontal ligament, osseointegrated implants should exhibit no clinically detectable movement and, therefore, healthy implants should appear to be nonmobile. There should be no mobility even in the presence of peri‐implant bone loss provided there is still an adequate amount of supporting integrated alveolar bone.

When monitoring the health of the peri‐implant soft tissues, the practitioner and hygienist should be cognizant of changes in soft tissue such as those to color, contour and consistency. The presence of a fistulous tract, for example, could indicate the presence of a pathologic process or impending implant fracture.

The significance of bleeding upon probing around dental implants is still being debated in the literature although it is generally accepted that bleeding upon probing or palpation may be an indication of peri‐implant disease [7–9]. This is because bleeding can occur before there are any histological signs of inflammation or it may occur concurrently with other signs of implant failure such as bone loss. However, as discussed below, routine (and, especially, aggressive) probing is not recommended for implant sites.

Radiographic interpretation is probably the most useful clinical parameter for evaluating the status of an endosseous dental implant. Invasion of the biological width and predictable remodeling, e.g., “saucerization,” leads to an average marginal bone loss of about 1.5 mm during the first year following prosthetic rehabilitation. This is potentially followed by an average vertical bone loss of 0.2 mm every subsequent year. Thus, if the progressive bone loss around a dental implant exceeds these averages, then this may be taken to be an indicator of an ailing or failing implant. Lastly, during radiographic evaluation, there should be no evidence of peri‐implant radiolucency because such a rarefaction usually indicates an active (or past) infection and/or failure of osseointegration or a recurrent cyst.

Natural Teeth vs Implants

Problems can arise with implants because of differences in the periodontal relationship between the gingiva and the structure it attaches to regardless of whether it is a natural tooth or an implant. The most crestal connection of the gingival cuff around both natural teeth and dental implants is the junctional epithelium which functions as a physical barrier to ingress of bacteria (and food debris), thereby limiting or preventing inflammation. However, the junctional epithelium differs between natural teeth and implants with respect to both the orientation of the fibers and the strength of the attachment.