**1. Introduction**

Periodontics is a science that aims to study the periodontium and the diagnosis, prevention and treatment of periodontal diseases, in order to promote and restore the periodontal health (Harvey & Emily, 1993; Roman et al., 1995).

The periodontium is the set of adjacent structures to the teeth that provides them with support and protection. These structures are: gingiva, cementum, alveolar bone and periodontal ligament (Harvey & Emily, 1993; Roman et al., 1995; De Marco & Gioso, 1997; Clarke, 2001).

Periodontal disease is the most common oral disease in dogs with up of 80% of animals affected (Riggio et al., 2011). This disease is progressive and involves two stages: gingivitis (reversible) and periodontitis (irreversible, but often controllable). It is caused by plaque buildup on teeth. The plaque is a smooth membrane, adhesive, contaminated with saliva bacteria and debris. Bacteria and bacterial products cause inflammation of soft tissue. The plaque becomes mineralised to form calculus, which migrates into the gingival sulcus, causing additional inflammation, loss of periodontal ligament, bone loss and ultimately tooth loss (Ford & Mazzaferro, 2007).

Medical problems that affect the oral cavity should be identified in its early stages, so that the animals can be treated before showing serious secondary systemic disorders related to malnutrition and/or infections (Pachaly, 2006). One should also be aware of ways to prevent the disease, as animal tooth brushing and the use of antimicrobials as an adjunct in periodontal therapy (De Marco & Gioso, 1997).
