CAD/CAM - international magazine of digital dentistry

18 I I case report _ use of CAD/CAM abutments Fig. 1_The patient presented with a fractured maxillary left lateral incisor. Fig. 2_After extraction of tooth 12, a transitional partial denture was delivered. Fig. 3_A post-op radiograph taken immediately after implant placement (OsseoSpeed TX, DENTSPLY Implants; Ø 3.5 S, L 13 mm). CAD/CAM 1_2014 _The traditional approach to soft-tissue con- touring of an implant-supported restoration is to initially shape the surrounding peri-implant soft tissue of an edentulous site with hand-prepared stock healing abutments, which are later replaced with a custom abutment and final crown, both of which are designed to fit into the space and form created by the stock abutment. However, with the continued advancement of both 3-D imaging and digital abutment design technology, the final abut- mentcanactasbothalinkbetweentheimplantand the crown, and as a tissue shaper that contributes directly to the final surrounding soft-tissue con- tours.Thisgreatlyaidstheclinicianinobtainingthe desired aesthetic outcome. Regardless of implant or healing cap diameter, the peri-implant sulcus shape often requires ad- ditional modelling to obtain more natural and optimised final restoration aesthetics. Traditional methods of tissue contouring include the use of temporary restorations to form the desired soft- tissue anatomy. Provisionals can be retained by bonding them to neighbouring teeth with properly shaped pontic contours that apply pressure to the peri-implant tissue in order to shape the tissue covering the implant.1, 2 An alternative method is to use abutments that support overcontoured pro- visional crowns, which push out the peri-implant tissue as it heals.3–5 When the tissue matures around these types of provisionals, it takes on the shape of the gingival portion of the tooth, pontic, or temporary crown. The abutment and final crown are then fabricated to match the tissue contours. A more efficient alternative to the traditional method for soft-tissue management is to employ patient-specific abutments that can effectively provide ideal anatomical formation of the soft tis- sue. These abutments can be designed with the de- sired specific profile that passively fills the healing cap-shapedsulcusfromthetopoftheimplantupto the sub-crestal tissue, and then expands just below the abutment shoulder region to the dimensions and contour of the tooth to be replaced. The lateral pressure applied induces the peri-implant sulcular tissue to stretch and adopt the abutment’s outer morphology as the shape of the sulcular inner wall. At insertion, the seating of a larger, more anatomical abutment design results in significant tissue blanching when the tissue is stretched. However, the blanching generally resolves within one to two days after abutment placement. Multi- ple clinical trials utilising large anatomical abut-Fig. 5 Fig. 6 Utilisation of patient-specific CAD/CAM abutments for long-term soft-tissue management Authors_Drs Julian Osorio & Robert B. Kerstein, USA Fig. 3 Fig. 4 Fig. 1 Fig. 2 CAD0114_18-20_Kerstein 14.04.14 11:45 Seite 1