Free excerpt - SAC Classification in Implant Dentistry

2 THE RATIONALE BEHIND THE UPDATED SAC CLASSIFICATION

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2.1 Definitions Case type: A class of implant-supported prostheses that share similar defining characteristics. For example, implant-­ supported crowns for single-tooth replacements, or short- span implant-supported fixed dental prostheses replacing three or four teeth and supported by two implants. Process: The implant dentistry “process” is defined as the full range of issues pertaining to assessment, planning, man- agement of treatment, and subsequent maintenance of the implant and prosthetic reconstruction; it does not merely refer to the clinical treatment procedures that are involved. Normative classification: In this context, “normative” re- lates to the classification that conforms to the norm, or standard, for a given clinical situation in implant dentistry. The normative classification relates to the most likely clas- sification of a case type. The final classification of a specific case may differ from the normative classification for the case type as a result of individual risk factors. Timing of implant placement and loading: Loading and placement protocols have been investigated by the ITI at its last four Consensus Conferences. Hämmerle and coworkers (Hämmerle et al, 2004) defined the timing of implant place- ment relative to the event of tooth removal in a site, relating this to healing events rather than a specific time frame. This classification is detailed in Table 1.

Implant loading protocols were also the subject of consen- sus conference reviews. At the Fourth ITI Consensus Confer- ence, Weber and coworkers (Weber et al, 2009) defined the timing of implant loading relative to its placement. These descriptions are summarized in Table 2.

Table 2 Implant loading protocols (Weber et al, 2009).

Classification

Definition

Conventional loading

Greater than 2 months subsequent to implant placement Between 1 week and 2 months subsequent to implant placement Earlier than 1 week subsequent to implant placement

Early loading

Immediate loading

Review article from the 4th ITI Consensus Conference on Loading Protocols by Weber and coworkers (2009).

Most recently, the relationships between the timing of im- plant placement (relative to the time that the tooth in the placement site was extracted) and the timing of loading of the implant with a provisional or definitive prosthesis in partially dentate patients were addressed by Gallucci et al (Gallucci et al, 2018). The outcomes of this review, correlat- ing the evidence for the various combinations of placement and loading protocol, are summarized in Table 3. Protocols that had multiple high-quality studies were deemed scien- tifically and clinically validated (SCV) and could be seen as suitable for routine use by appropriately trained and expe- rienced clinicians. Clinically documented (CD) approaches had less support in the published literature but did possess reasonable long-term clinical documentation to allow their use in specific situations. Finally, clinically insufficiently documented (CID) protocols lacked sufficient scientific evi- dence and clinical documentation to be recommended for use. This review built on previous consensus meetings where definitions of the placement and loading protocols were developed.

Table 1 Implant placement protocols (Hämmerle et al, 2004).

Classification Definition Type 1

Implant placement immediately following tooth extraction and as part of the same surgical procedure

Type 2

Complete soft tissue coverage of the socket (typically 4 to 8 weeks)

Type 3

Substantial clinical and/or radiographic bone fill of the socket (typically 12 to 16 weeks)

Type 4

Healed site (typically more than 16 weeks)

Review article from the 3rd ITI Consensus Conference on the Placement of Implants in Extraction Sockets by Hämmerle and coworkers (2004).

6 The SAC Classification in Implant Dentistry