CHAPTER 6 Evaluating the implant candidate

Because the ultimate outcome of an implant intervention depends upon all the factors contributing to the site's general health, the patient must be carefully evaluated both clinically and subclinically. It is not adequate to examine the proposed site or sites solely by eye or even by x-ray. Although local conditions are usually easily observable and many systemic conditions are reflected by the condition of any remaining teeth, the supporting bone, and the soft tissues, the implant procedure calls upon metabolic processes affected by subtle conditions in the body. To be secure, the implant must be surrounded by healthy new bone and soft tissues. Any condition, either local or systemic, that might detract from normal healing may be a contraindication. Of course, some of these conditions may be temporary, and the operator can merely postpone the implant intervention until a more opportune time. Other long-ranging, recurrent, or permanent conditions require that the operator carefully balance the pros and cons of the individual situation and base his decision on what would be most beneficial to the patient.

Information for evaluating the candidate should be gathered by eye, x-ray, tissue biopsy, and chemical analysis, if necessary. A history of the patient's health and oral habits will prove particularly valuable in relation to recurrent or permanent conditions that might contraindicate an implant intervention. The following conditions and characteristics should be considered basic to a preoperative investigation and evaluation of a presenting candidate.

INITIAL INVESTIGATION

Before dentistry of any sort is started, an all-inclusive dental examination must always be made by the dentist to form the foundation for all subsequent therapy. The evaluation of the data helps the dentist arrive at a diagnosis. Naturally, the more thorough the examination, the more benefit derived by the patient. The degree of thoroughness of the

examination is directly proportional to the dentist's powers of observation.

The examination should proceed in an organized and systematic manner. Part of the examination—including a questionnaire regarding the patient's name, address, age, occupation, and his physician's name and address—may be filled out by a dental assistant. That part of the questionnaire concerning the patient's medical history should be reviewed by the dentist himself; he alone has had the training to spot possible toublesome conditions.

Many questionnaires have been devised by various clinicians for diagnostic purposes, and several of them are excellent. However, a questionnaire de-signed for possible implant recipients should be unusually inclusive. Pertinent questions that could re-veal hormonal imbalances, nutritional deficiencies, a history of heart disease, diabetes, tuberculosis, blood or bone dyscrasias, swollen glands, allergies, and habits such as grinding or clenching the teeth and biting the lips, tongue, or cheeks should be included.

The questions can be arranged in a number of ways. Linkow's questionnaire has proved most useful (Fig. 6-1), but another format might be just as successful. No matter what its style, the questionnaire should be easy to file as part of the patient's continuing record.

After taking the patient's medical history, it is a good idea to photograph the patient's facial pro-file and teeth in occlusion. These photographs will provide a visual history of the patient's progress from his first visit to the completed prosthesis.

EVALUATING LOCAL CONDITIONS

The structure and condition of the teeth, alveolar bone, periodontium, oral mucosa, tongue, muscles, and bones of the skull all affect the possibility of an implant intervention and its fate. These organs and tissues will be discussed here in terms of

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