Application of the chronic disease model to IPD suggests that to be most effective, programs of prevention and treatment include measures to address as many of the identified risk factors as is possible. It remains to be determined if TO is involved in the initiation of IPD, for example, if individuals with TO are at greater risk for the development of IPD. There is evidence that TO is a risk factor in the progression of IPD. Tooth mobility is associated with and is a risk factor for increased attachment loss and increased bone loss in patients with periodontitis. Tooth mobility can be reduced by occlusal treatment. Clinical trials involving patients with periodontitis clearly establish that a better clinical periodontal attachment level response to treatment is obtained when occlusal adjustment is included as part of the treatment plan. Patients with advanced periodontal involvement benefit from occlusal treatment in terms of increased stability for the teeth and also in terms of oral comfort. Finally, There is no evidence that without occlusal treatment, periodontal patients who are in careful maintenance programs are more likely to suffer recurrence of IPD.