[25] presented an approach using a groove, plate, and strut, which involved minimal preparation of the posterior abutment to receive a RBFPD using a base metal alloy. Botelho et al. [26] advised that the major retainer should have a wrap-around configuration on at least three surfaces of the abutment or have strategically placed opposing axial grooves or slots for long-span prostheses that replace two or more missing teeth. Another report [27] described a methodical preparation for posterior partial veneered restorations that provides sound posterior occlusal function and isolates the occlusal contact area in the enamel to maintain

the vertical dimension of occlusion. It is especially effective when a prosthesis has not been seated this website very long to replace the missing teeth, MEK activation and the intact mesial and distal teeth incline toward the missing space (Figure 9 and Figure 10). The overcasting technique was originally a technique designed to avoid removal of restorations, such as fractured metal ceramic fixed partial dentures [28], [29] and [30] or adjacent FPDs [31]. The technique remarkably developed through the use of adhesive resin cement with metal conditioners [32] and [33]. An overcasting restoration may provide faster treatment, fewer appointments, less discomfort, simpler laboratory procedures, and lower cost compared to replacing the restoration. Fig. 11 shows a preparation with two retentive

pinholes for an overcasting in response to an esthetic request from the patient. buy Baf-A1 Although the typical design of resin-bonded overcastings has not yet been established, it is generally easy to add mechanical structures such as grooves and pinholes in overcastings compared to intact

teeth. In this situation, the overcasting was cast with type III gold alloy with highly filled composite (Fig. 12). The facial surfaces of the metal premolar restorations were replaced with an overcasting with indirect composite using an adhesive luting agent (Super-Bond C&B Ivory, Sun Medical Co., Ltd., Moriyama, Japan) which resulted in a good appearance (Fig. 13). Evaluation of the current status indicates that the design of posterior resin-bonded prostheses has almost become D-shaped. This design is almost complete with no clinically significant problems and will be used for the foreseeable future. On the other hand, there is no typical standard yet for the design of anterior resin-bonded prostheses. The available surfaces to be bonded are limited from the esthetic viewpoint to the lingual surface and a portion of the proximal surface in the anterior region. Hence, it is difficult to use a wrap-around design in this region. Consequently, there is a limitation to adding mechanical retention obtained by design although the improvement of the bond strength of the adhesive resin material is definitely needed, particularly in this region.