A countersink must be used because of the shape of the implant, which is not completely cylindrical even in the case of the Straight implant. The neck part of the implant is conical. Correct use of the countersink ensures optimal stress distribution in the area of the marginal bone and limits excessive mechanical stress on the bone around the implant neck. Countersinks for guided surgery are color-coded according to the corresponding implant series. They have been designed for use exclusively during fully guided surgery using surgical templates.