Background Due to increasing numbers of adult patients, orthodontists are being confronted more and more with periodontal problems. Coordination amongst orthodontists, periodontists and general dentists is useful in preventing and stopping periodontal disease. The main objectives of this survey were to evaluate the technical knowledge, techniques and attitudes employed by French orthodontists, periodontists and general dentists in adult dental care. Methods A cross-sectional online survey was distributed to French dentists. The questionnaire, consisting of 30 questions, was divided into six sections covering treatment programs and the forensic environment. Results One thousand one hundred twenty-two complete answers were recorded. Adults undergoing orthodontic treatment represented 19.9% of the orthodontists' patients, but only 2.67% of the general dentists' patients. Communication between clinicians was rated as good, greater than 3 out of 5. Before treatment, orthodontists were less alarmed than generalists regarding bleeding, recessions, increased probing depths, halitosis and hyperplasia. During treatment, orthodontists never or only occasionally performed palpation or probing in 54.2% and 84.6% of cases. Gingivitis and recessions were the main reasons for consultations for 22.0% and 20.1% of general dentists and periodontists after orthodontic treatment. Of the practitioners surveyed, 43% felt that they experienced a setback in the ortho-periodontal treatment. Conclusions This study revealed discrepancies in the knowledge and attitudes of practitioners. Therapeutic management remains one of the major challenges of multidisciplinary treatments. Continuing education needs to be further developed in this field.