KEEPING THEM PEARLY WHITE AND SMOOTH
PERIODONTOLOGY FOR THE DENTAL TECHNICIAN Jan Bellows, DVM, DAVDC, DABVP (Canine and Feline) Periodontal disease is the most common small animal ailment. Eight out of 10 dogs and cats older than five will suffer from periodontal disease. If periodontal problems are left untreated, bacteria and toxins can be absorbed into the blood stream and, in some instances, can cause permanent damage to internal organs, decreasing the pet’s life span. Periodontal disease starts with plaque, which attaches to teeth and gingival surfaces. Plaque is primarily composed of bacteria, white blood cells, and saliva. When removed daily, plaque doesn’t cause problems. If left to accumulate, mineral salts in saliva mix with plaque, forming hard calculus. Without daily plaque removal, more plaque accumulates on top of the calculus, extending under the gingiva. At first, there is little difference between the bacteria above (supragingival) and below (subgingival) the gingival margin in healthy sites. Most supragingival plaque bacteria are gram positive, non-motile, aerobic cocci. As periodontal infection progresses, destructive gram-negative, motile, anaerobic rods predominate.
Disease predisposition
The cause of periodontal disease is multifactorial. Many elements factor into the equation of why some small animals develop disease, while others do not. Some of the most common criteria that predispose some animals to periodontal disease include: • Breed- small breeds are more prone to periodontal disease due to the proximity of the teeth and the relative thinness of the bone around the incisors. • General health- animals that have compromised health or that are immunologically suppressed cannot fight periodontal pathogens effectively. • Dermatological disease- animals with dermatological disease many times chew at their coat, embedding hair under the gum line and, thereby, promoting periodontal disease. • Nutritional health- animals on a poor diet often have less immunity to disease. • Age- older pets are more prone to periodontal disease. Ultimately, the destruction of tooth support (periodontium) is responsible for the loss of teeth. The height of the alveolar bone is normally maintained by an equilibrium between bone formation and bone resorption. When resorption exceeds formation, bone height is reduced. In periodontal disease, the equilibrium is altered, so that bone resorption exceeds bone formation.
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Plaque-laden calculus plays a key role in maintaining and accelerating periodontal disease. When calculus extends deep into the subgingival tissues, the potential for repair and reattachment is lost without medical or surgical intervention. The therapeutic importance of plaque and calculus removal by the veterinarian and follow-up home preventative care by the client cannot be overemphasized.
The periodontal exam
Periodontal pockets result when the periodontal ligament loses part, or all, of its attachment to the tooth. The periodontal pocket is defined as a pathologically deepened gingival sulcus. The clinical pocket depth is defined as the distance from the free gingival margin to the base of the pocket. Diagnosing periodontal disease and assessing the response to treatment are, in part, based on pocket depth measurement. The measurement of clinical pocket depths by a probe is the backbone of a thorough periodontal examination. The periodontal probe is marked in millimeter gradations and gently inserted in the space between the gingival margin and the tooth. A probe will stop where the gingiva attaches to the tooth, or at the apex of the alveolus, if the attachment is gone. Mediumsized dogs without periodontal disease should have less than 2 mm probing depths, and cats should have less than 1 mm. Each tooth is probed on a minimum of four sides. Abnormal probing depths of all teeth should be noted on the dental record, and a treatment plan should be mapped out before therapy begins.
Gingival recession involving the left maxillary fourth premolar, extraction is indicated. Photo courtesy of Dr. Jan Bellows
