A single MI session as an adjunct to conventional periodontal therapy could not be proven to be of long-term beneficial additive effect with regard to prevention of relapse in oral hygiene behaviour. Desirable standard of self-performed infection control after active periodontal treatment predicted the retention of sufficient oral hygiene behaviour over time.

The results describe a psychosocial process that elucidates the importance of building a trustful relationship with the patient, feeling secure in one's professional role as a DH and last but not least, the importance of having support from colleagues and the clinical manager to be successful in the prevention and treatment of periodontal diseases.

Dental hygienists' considered that competencies in the treatment of periodontitis patients were related to the practice of behavioural interventions as part of therapy. A stimulating and supportive work environment, with opportunities for professional development, is important for work satisfaction.