Bone augmentation: one-stage/simultaneous approach versus two-stage/staged approach
All bone augmentation techniques, except alveolar distraction, can be performed in a one-stage approach (bone augmentation and implant placement simultaneously) or a two-stage approach (bone augmentation in a first stage and implant placement in a second stage, 4 to 6 months later).
The choice between simultaneous or staged approach depends upon the following clinical parameters: treatment duration, morbidity, risk:benefit ratio, and implant outcome.
Optimal Timing for Bone Augmentation
Bone augmentation procedures (simultaneous or staged approach) can be performed at different times after tooth extraction. The later the procedure is performed, the more bone resorption occurs. Consequently, bone augmentation procedures must be performed as soon as possible.
For most bone augmentation procedures, a soft tissue primary closure is recommended to prevent material exposure. In these cases, a 6–8-week healing period after tooth extraction is considered as the optimal timing.
Optimal Timing for Implant Placement
The decision to place the implant at the time of the augmention procedure depends on the ability to obtain the primary stability of the implant and the ability to achieve the soft tissue closure. One must keep in mind that immediate implantation usualy increases the risk of complication of the bone augmentation procedure (Table 36.1).
Risk of Complication with Bone Augmentation Procedures
Complications may result in inflammation, infection or reduction of new bone gain.
The quality of the risk depends on the procedure itself and on the soft tissue healing at the time of the surgery (Table 36.1). Soft tissue covering is mandatory for membranes and block bone grafts. Complications are frequent with non resorbable membranes.