Only by controlling plaque early and consistently, before periodontal and restorative problems require intervention in the form of a full prosthetic and periodontal reconstruction, the continued maintenance of a full dentition is assured. Plaque control is not merely continued prophylaxes, but a striving for a healthy biologic situation with the placement of every restoration. This is attainable only through ensuring a normal attachment apparatus and establishing that all restorative margins be accessible to plaque control measures. Deep, subgingival restorations are not only difficult to place and finish correctly, but, by providing an environment conducive to microbial plaque retention and proliferation, also lead to inflammatory periodontal destruction and recurrent carious lesions. Early detection, although difficult, is essential to avoid excessive destruction of the tooth and its supporting structures. A deterrent to early detection may be the response of the patient's tissue. Paradoxically, if the patient's periodontal tissues respond in a fibrotic manner to early gingival inflammation, rather than in a dramatic, edematous manner, the situation may appear clinically healthy. Waerhaug discussed "submarginal gingivitis," a situation in which the tissue will appear pink and firm, elicit to exudate or bleeding on probing, and mimic healthy to the casual examiner. When this is coupled with the difficulty inherent in detecting early recurrent carious lesions, resulting from the radiographic superimposition of the existing restoration or the deep subgingival extent of the restoration, the situation becomes all the more demanding of the practitioner's efforts.