Free excerpt - SAC Classification in Implant Dentistry

A. DAWSON, W. MARTIN, W. D. POLIDO

Table 9 Restorative factors.

Restorative factors

Risk or degree of difficulty

Low

Medium

High

Site factors

Adequate. Space available for ideal anatomy of the restoration. Adequate. Possible to create an anatomically and functionally correct planned restoration. Adequate. No prosthetic soft tissue replacement will be necessary.

Compromised. Can be resolved without adjunctive therapy. Compromised. Can be resolved without adjunctive therapy.

Inadequate. Adjunctive therapy will be needed to achieve a satisfactory result. Inadequate. Adjunctive therapy will be necessary to achieve sufficient space for the planned restoration. Inadequate. Prosthetic replacement of soft tissue will be needed for esthetics or phonetics.

Prosthetic volume

Interocclusal space

Volume and characteristics of the edentulous ridge

3.7.1.1 PROSTHETIC VOLUME

Crown

This refers to the 3D space required for the overall prosthe- sis. The required space will depend on thematerial planned for the restoration (framework, veneeringmaterial, denture teeth, etc) and the associated implant components (abut- ments, copings, attachments, screws) (Figures 62 and 63). It is described in terms of themesiodistal, orofacial, and inter- occlusal space, and where it equates to a volume that is adequate for a restoration with ideal anatomy, it is low risk. A space that is compromised by being either greater or smaller than ideal will present increased difficulty. If the volume can be rectified without adjunctive therapy, it is re- garded as having moderate risk , whereas a case needing significant additional treatment is classified as a high risk. The definition of interocclusal space can vary with the re- source; authors often use varying reference points: 1) im- plant platform to opposing occlusal table, 2) abutment lev- el to opposing occlusal table, 3) planned restorative margin to opposing occlusal table, or 4) ridge to opposing occlusal table. It is important to verify these reference points prior to using published numbers in order to prevent potential com- plications, as a difference of ~3 mm (when utilizing bone- level implants) can exist between reference 1 and 4. Minimum interocclusal space requirements (reference points ridge to opposing occlusal table): • Crowns: 7 mm (Figure 64) • Fixed dental prosthesis: 7 mm (Figure 64) • Overdenture (individual attachment, eg, Locator, Novaloc [Straumann]): 8–11 mm (Figure 65) • Overdenture (bar with attachment): 14 mm (Figure 66) • Hybrid (denture tooth, acrylic resin, and framework): 12–15 mm (Figure 67) • Hybrid (monolithic zirconia): 11–14 mm (Figure 68) 3.7.1.2 INTEROCCLUSAL SPACE

Coping (when indicated)

Screw

Abutment

Fig 62. Prosthetic volume for a single-tooth screw-retained implant restoration.

Veneering Material

Screw

Framework

Abutment

Fig 63. Prosthetic volume for a full-arch screw-retained implant restoration.

The SAC Classification in Implant Dentistry

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