The invention relates to a dental device for dilating interdental spaces. The device comprises two interdental matrices that can be inserted into interdental spaces two retaining arrangements to retain the interdental matrices, and a spacer device for guiding the retaining means in parallel and for separating teeth. The device provides access to the mesial and distal tooth surfaces in the areas of the interdental spaces and prevents gingival injuries and damages to the dental enamel caused by pressure. The device can be used in prophylactic or restorative odontotherapeutical methods.