Determining the positioning of the tooth concerned
This step plays a key role in our protocol. Determining the ideal position of the tooth and its placement will allow us to preserve the dental tissue to the maximum extent possible and guarantee optimal durability of the restoration.
The goal is to provide sufficient space for a veneer or direct composite resin restoration. In order to avoid parasitic movements on the other teeth, the rehabilitation of the riziform tooth with the mock up facilitates this positioning step.

Transversal direction

Sufficient space must be maintained for the restoration (0.5 mm for veneers and 1.5 to 2 mm for the direct technique) (27). The mesial (M) and distal (D) spaces must be evenly distributed to better mimic the tooth tissue (same amount of Enamel/Dentin in M and D). To achieve this, the tooth must be positioned in the middle of its space. In cases of dental disharmony with persistent anterior space, we recommend either a diastema distal to the lateral (studies show that this is the least unsightly location in a smile) (3,31) or a diastema distal to the canine. In general, diastema is considered unsightly by the general population (26).

Vertical direction

Within the framework of a rehabilitation with a facet, a palatal covering can be performed (32,33). Depending on the patient’s occlusion, an anterior overlap of -2 to 0 mm may then be indicated in order to avoid excessive preparation of the incisal edge of the riziform tooth. In addition, the taller the tooth, the lower the width/height ratio will be and the more esthetic the tooth will be (23,24,34). This notion is to be taken into account if the space of the riziform tooth is too large and therefore requires an increase in its M-D diameter. According to the situation, to avoid any periodontal surgery, we recommend to take advantage of the orthodontic treatment in order to harmoniously position the gingival edges (35).

Antero-posterior direction

Since an additional thickness will be added to the vestibular of the riziform tooth, we recommend placing the tooth in question in the palatal area and thus avoiding an alignment of the incisal edge with the other teeth in order to limit dental preparations.
The fact of absolutely wanting to close the space between the teeth can lead to a tooth that is too square (especially in the case of dento-dental disharmony) (34). If the M-D space is too large, either the diameter of the adjacent teeth can be increased or the incisivo-canine block can be receded. If these solutions prove to be unattractive or dysfunctional, a 1 mm canine advance (thus having a light canine class II) to close more of the D-space of the riziform tooth, without disturbing the anterior guidance can be done.