Repeated or sustained contact of teeth other than during mastication is called as:
Parafunction in dentistry refers to those activities of the stomatognathic system that would be considered to fall outside of functional activities. Lip and cheek chewing, fingernail biting, and teeth clenching are examples of parafunctional activity.
Bruxism (GPT-9): 
1. The parafunctional grinding of teeth.
2. An oral habit consisting of involuntary rhythmic or spasmodic nonfunctional gnashing, grinding, or clenching of teeth, in other than chewing movements of the mandible, which may lead to occlusal trauma.
Malfunction
Parafunction
Hyperfunction
Hypofunction