**8.10 Parafunctional habits-bruxism**

Bruxism is a movement disorder of the masticatory system that is characterized among others by teeth grinding and clenching during sleep as well as during wakefulness. Since there is no periodontal ligament between the implant and surrounding bone, the occlusal load is directly transmitted [64]. Even though bruxism is likely to be a risk factor for mechanical complications in the implant periphery, it is unlikely to be a potential risk factor for biological complications [65].
