Risks and complications
Risks for flapless surgery
Although reflecting a muco-periosteal flap is still considered the gold standard for placing implants, the flapless approach is becoming increasingly recommended as a minimally invasive surgical option. There are three ways of performing flapless surgery:
- immediate post-extraction placement
- punch flap
- trans-gingival approach
The approach which involves raising a flap provides good bone visibility, safer distribution of keratinised tissues and allows the possibility of grafting. However, this approach is also associated with longer surgical times, postoperative inflammation and crestal bone resorption.
“The flapless approach is becoming increasingly recommended as a minimally invasive surgical option”
In cases involving fresh extraction sockets, flapless implant placement is highly recommended since it seems to be the best way to maintain tissue morphology. But this too is not without its disadvantages: it is harder to see apical lesions or remove granulation tissues, and it is not possible to augment the contour of the ridge with the flapless approach (Cosyn et al. 2012).
Regarding punch and trans-gingival approaches, only limited and short-term benefits for postoperative healing have been reported compared with open flap surgery (Aizenberg et al. 2013). Punching needs a large amount of bone volume and wide gingiva, since it removes about 5mm of keratinised tissue. Both punching and trans-gingival approaches have limited visibility of bone topography, and they are both associated with a risk of intrabony contamination by bacteria, epithelium or connective tissue.
“Both punching and trans-gingival approaches have limited visibility of bone topography”
A meta-analysis comparing flap and flapless approaches found no significant differences between the rates of implant failures (Chrcanovic et al. 2014). This could be due to insufficient statistical power or the presence of confounding factors (grafting, extraction sockets, guided surgery, etc.). Another more recent meta-analysis revealed that flapless procedures may increase the risk of implant failures, especially when loaded with immediate or early approaches. Nevertheless, it was reported that flapless procedures preserved bone tissues better and were associated with lower levels of bone resorption (Zhuang et al. 2018).
Since the flapless procedure is a ‘blind’ surgical technique (meaning that the underlying bone anatomy remains unseen), the risk of perforating the cortical plates increases, as does the risk of placing implants outside the bony envelope. Even in the case of guided flapless procedures, the risk of perforation persists due to the unavoidable deviations which occur during guided surgery. Navigation has been proposed as a way of performing flapless surgery with fewer risks, but this technology is currently too complex and too expensive to be widely utilised.
“The flapless procedure is a ‘blind’ surgical technique”
Flapless approaches should only be indicated in cases where conditions are suitable, with ‘good bone and good gingiva’.
The speaker stated that the risks associated with the procedure can be safely managed only after a proper and individualised treatment plan is drawn up. To emphasise this, they quoted the saying: ‘failing to plan is planning to fail’.