Flap- or flapless
- Measure the distance from the alveolar crest to the mandibular canal the mental foramina or other relevant anatomical landmarks on the 3-D images.
- Flapless implant placement and immediate restoration favour healing of surrounding tissues and aesthetic outcome.
- During single implant surgery a higher precision can be achieved though the fit of the guide to the occlusal plane of neighbouring teeth.
- The responsibility for the outcome and patient safety during flapless guided surgery remains with the surgeon.
- The maximal and not the average deviation recorded for a specific planning system is relevant for the clinical safety.
Flapless Implant Placement
Flapless implant surgery for single tooth replacement is a minimally invasive procedure that can be performed using custom fabricated surgical guides made on occlusal casts or derived from 3D image planning softwares with integrated 3D images of the jaw bone and of the planned prosthesis. This often achieved through a double-scan procedure with fiducial marker-based matching, or more recently by integrating in the CBCT derived planning images a scan of the diagnostic tooth setup. DICOM data from the CT/CBCT examination of the patient are combined with the STL data from optical digital high-resolution scan of the patient preoperative master cast. (SmartFusionTM, Nobel Biocare). This can even include information on soft tissues.
The doctor should inform patients that computer guided surgery implies additional costs. However the cost-effectiveness involving the reduction of surgery time, post-operative discomfort and better soft tissue healing may render it worthwhile.
The fit of the surgical guide, often fabricated by stereolithography, on the occlusal surfaces of neigbouring teeth enhances the precision of its position. The precision of matching the actual implant position with the preoperative planning is superior to what is achieved with free hand surgery.
Several clinical papers reported excellent short- and long-term survival rates ( ≥ 98 %) for implants placed using a flapless approach with the option of delivering immediately a pre-fabricated temporary prosthesis. The scientific evidence available reveals that guided surgery leads to at least as good implant survival rates as conventional free hand protocols. Under appropriate conditions it is a rewarding procedure for patients because of minimal bleeding and postoperative discomfort. Patients benefit from having implants placed flapless and loaded immediately.
Prior to surgery patients are sometimes placed on a prophylactic antibiotic regimen although strict asepsia may reduce this need. Choice of antibiotics is usually dictated by the patient’s health history and consideration of potential allergies. Local (for anterior parts of the mouth) or regional (for molar areas ) anesthesia is performed.The surgical site is swabbed with an antiseptic.
The sterile surgical guide is positioned. A circular punch can be used to remove the mucosa prior to the use of the round bur. If one wants to preserve the gingival width a very limited scalloped of the mucoperiosteum can be performed. This does not influence the precision of the transfer of the planned implant position. Site preparation is completed with the classical series of drills and the appropriate implant size is installed. Sutures are normally not needed. The use of the template can be limited to the pilot drilling or for the entire osteotomy including the implant placement. Freehand enlargement of osteotomy hole results in significantly less accuracy than with a fully template guided drilling and implant placement.
Resonance Frequency Measurement can be performed prior to the insertion of the healing/final abutment or a Periotest evaluation after abutment installation. The patient is referred to the restorative dentist who can place immediately a (provisional) restoration. The dentist has several options: from impression-taking and using custom abutment to the use of pre-fabricated stock abutments. The placement of the (final) restoration the same day as surgery improves the soft tissue remodelling and aesthetic outcome. The restorative dentist makes these choices. The final restoration should preferably be screw-retained. Flapless single implant placement often reduces postoperative bone remodeling, mucosal recessions and tends to preserve peri-implant papillae.
Once the restoration has been placed and the occlusion has been evaluated, the patient should be placed into a maintenance program including periodontal, functional and prosthetic evaluation. The implant should be monitored for mobility and a periapical radiograph should be taken at the time of prosthetic restoration, after one year and later if clinical arguments arise.