A control arrangement and a method for controlling a computer comprised in a dental apparatus, said dental apparatus (100) comprising at least a computer (101) and its display (111) functionally connected to each other, a dental unit (102, 104) and a control arrangement which comprises control means (112, 116, 117) for controlling the functions of at least said computer and dental unit, wherein at least some of the control means (116) used to control said computer (101) are arranged in connection with said dental unit (102, 104) so as to allow the computer (101) to be controlled via the control means (116) arranged in connection with the dental unit (102, 104).