GUIDED SURGERY

NobelGuideĀ™

The type of surgical guide in conjunction with the bone quality and volume will drive the surgical procedure. Guided surgery will afford the least invasive surgery protocol. All aspects of bone quality, volume and topography are discovered through CT or cone beam computer tomography (CBCT) and virtual implant placement before any incision is made. The surgical guide is either bone, tissue or teeth borne. In most instances only minimal tissue reflection or excising a small circular amount of tissue with a tissue punch through the surgical guide are needed.

The bone is scored with a round burr through the guide, followed by the pilot drill according to the drill protocol to establish the osteotomy depth and angulation. Copious amounts of pre cooled, sterile saline solution should be used to irrigate the drills and bone. Some guides will allow the use of successively larger drills through the use of interchangeable bushings in the guide, just the pilot hole or a number of guides for each larger diameter drill. In which case the surgical guide is changed to accommodate the next larger drill or discarded after the initial pilot hole. Successively larger diameter drills are used in accordance with manufacturer guidelines in regards to bone quality and implant diameter to achieve the most ideal osteotomy dimensions.

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 grafting 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 implant. A reduced treatment time frame, less trauma and scarring in addition to reduced treatment cost make this option a popular treatment choice.