TRADITIONAL SURGERY

The type of surgical guide if any in conjunction with the bone quality, volume and type of final restoration (cementable, screwretained, overdenture, hybrid, PIB). will drive the surgical procedure. Any surgical guides are either tissue or teeth borne. Assuming adequate bone is available the patient is anesthetized and the tissue sectioned along the edentulous crest. Releasing incisions are made to create a buccal and a lingual flap. If the papilla to the adjacent teeth is still intact the releasing incisions will be 1mm to 1.5mm distally and mesialy respectively from the preserved papilla's. In case there is no papilla present, the releasing incision line will be made right next to the existing teeth. The tissue is carefully released away from the underling bone structure with curettes. Tissue flaps can be tied back with sutures to allow unimpeded access. Underlying bone structures are visually evaluated to confirm adequate bone width and length. Sometimes it is necessary to flatten the bony crest to create a more favorable topography for implant placement, especially when larger diameter implants are being placed.

Screwretained restoration

The osteotomy should be in the center of the edentulous space in the mesial distal dimension. Depending on the final restorations modus of fixation and whether the restoration is for a anterior or posterior tooth, the buccal lingual position of the osteotomy varies. Anterior screw retained restorations require a screw access hole through the cingulum and the osteotomy therefore has to be more lingual with no labial inclination. Cementable anterior restorations are more forgiving in regards to the labial-lingual position of the osteotomy. The osteotomy for cementable anterior implant restorations should be in the center of the proposed final restoration and a slight labial inclination.

Cementable restoration

Posterior screw retained restorations dictate a dead center lingual-buccal position, directly underneath the central fossa of the future final restoration with no inclination buccaly or lingualy. As with anterior cementable implant restorations, posterior cementable restorations are more forgiving in regards to the buccal-lingual osteotomy position and inclination.

Safety zones

The bone is scored with a round drill through the guide or free hand, followed by the pilot drill according to the drill protocol to establish the correct osteotomy depth and angulation. Copious amounts of pre cooled, sterile saline solution should be used to irrigate the drills and bone. Successively larger diameter drills are used to widen the osteotomy in accordance with manufacturer guidelines in regards to bone quality and implant diameter to achieve the most ideal osteotomy dimensions. The final osteotomy should have a zone of safety of 1.5mm to 2mm to any vital structures (adjacent roots, mandibular canal). If implants are to be placed next to each other 3mm of space should exist from one implant to the next.

Tap drill

Depending on the bone quality and structure, the bone is pre tapped only at the cortical crest or the complete depth of the osteotomy. D3 and D4 type bone will in most instances not require pre tapping. Instead the implant is allowed to tap itself in to the softer bone at the time of implant insertion in to the under sized osteotomy. Once the osteotomy is finalized the implant is picked up with a high torque surgical motor and driven in to the osteotomy site with a low speed (30rpm) and clock wise setting. Avoid contaminating the implant body by touching or placing the implant on the instrument tray before insertion.

Feature indicator

The polished collar of the implant should be above or flush with the crest of the bone, depending on manufacturer recommendation. Disconnect the surgical motor from the implant and evaluate the implant position. The anti rotational feature of the implant should be positioned in relation to the angulation of the implant. The implant carrier or fixture mount of the implant has in most cases markings indicating the anti rotational feature position. For instance, if the implant is inclined toward the buccal, the indicator should be on the buccal as well. If the inclination is towards the mesial, the marker needs to be on the mesial too. Utilize a hand ratchet to finalize proper implant position and remove the implant carrier.

Two stage surgery

Closing the tissue can be done as a one stage or two stage procedure. Minor bone graft procedures may be performed before suturing the implant site. A two stage surgery requires suturing the tissue flap over the installed implant at the initial implant placement and a second surgery after the initial healing period to uncover the implant. The two stage protocol involves installation of a low profile cover screw (included with most implants) before closing the tissue over the implant and changing the cover screw with a trans mucosal healing abutment (often a separately purchased item) at the second stage uncovery. This approach requires additional time to let the tissue heal and mature around the trans mucosal healing abutment.

One stage surgery

A one stage surgery entails suturing the tissue around the trans mucosal healing abutment at the time the implant is placed, eliminating a second surgery to uncover the implant. The trans mucosal healing abutment is installed instead of the cover screw and the tissue sutured around the healing abutment, allowing the tissue to heal and mature around the trans mucosal healing abutment. A reduced treatment time frame, less trauma and scarring in addition to reduced treatment cost make this option a popular treatment choice.