This classification does not take into account the morphology of natural feminine and masculine shapes of teeth. To satisfy the needs of the patient, the dental prosthesis must be as similar to the natural tooth as possible. To achieve this, Merz Dental developed a modern shape classification based on the studies of Prof. Dr. SIEBER (Freie Universität Berlin) regarding the measurement of teeth on test persons with a complete set of teeth. Every single anterior was measured and catalogued according to shape, size and recurring characteristics as well as special characteristics. This served to prove that the entire spectrum of human tooth shapes can be reduced to three basic shapes C, B and I.

The CBI® system patented by Merz Dental makes it possible to imitate nature perfectly. The definite allocation to C, B and I is determined mathematically by measuring the maximum mesiodistal width between the enamel ridge in the respective thirds of the tooth axis. If this method is used consistently, a variety of shapes are derived based on the morphology of natural feminine and masculine teeth - the CBI® system.