Technology is certainly a hot-button topic for many dentists. There are those who embrace technology. These doctors look for ways in which a new gadget, technique or product can improve not only the lives of their patients, but can also help them and their staff. Then there are the naysayers. You know the type. Those who think that any alternative way of doing something is wrong, evil or just plain unnecessary, because they themselves either don’t do it or did not invent it. Look, it’s always good to be skeptical. I am never the first in line for any new product. However, we owe it to our patients to utilize newer methods that increase the safety, the accuracy and the efficiency of anything we do in dentistry. So let me step down off my soapbox for a moment to present a clinical case showing how the integration of CEREC, GALILEOS and the e.max abutment block allows me to not only place implants, but deliver a final restoration with micron accuracy.
There are lots of great CBCT machines on the market, so what makes GALILEOS any different? Apart from its superior metal artifact reduction software (MARS), GALILEOS allows doctors to enhance the 3D radiographic data of a cone beam with the 3D optical scan data of CEREC. CBCT is an excellent modality for evaluating bone; however, artifacts from crowns and the profile of the soft tissue are not as easily visualized on a scan. By scanning the patient in CEREC, exporting a crown form or “proposal,” we can have the best of all worlds. CEREC is an excellent machine for scanning not only the soft tissue, but the clinical crowns of the adjacent teeth and, more importantly, the anatomy of those teeth. The implant platform should not only be placed in the center of the edentulous space, but should be situated about 3-4 mm below the CEJs of the adjacent teeth. The implant platform should be placed no deeper than 5 mm below the contact points of the adjacent teeth to grow healthy interdental papillae. By using barium sulfate teeth or relying on just the CBCT, there is now a way you can place your implants and take these variables into account. By using the option of a pilot drill path, we can plan the ultimate position of the abutment screw in a screw-retained crown. The pilot path shows up as a yellow pole in the GALILEOS software (Fig. 1).
Immediate implants are hard. Some, falsely, may tell you that an immediate implant just means you take a tooth out and stick an implant in the hole. Wrong. So wrong I would say it’s almost criminal! First, the hole is drilled incorrectly. Most sockets are too far to the buccal as teeth don’t need the 2 mm of bone on the buccal and lingual that implants do. Second, we have to engage at least 3 mm of bone apical to the tooth socket. Due to the sloped nature of the tooth socket, this is problematic to say the least. Next we need to place our implant somewhat below the crest of the socket to take into account some bone shrinkage as the socket heals. So it’s a lot harder than it looks. Enter guided surgery. By removing the tooth atraumatically and saving the buccal plate, and then placing that implant in the perfect position, we can preserve the bone around the implant. We can preserve the height and amount of soft tissue. In this case, we utilized an Optiguide, which was made from a scan of the patient in CEREC and the data sent electronically to SICAT in Germany without a model. (Fig. 2).
As stated earlier, by utilizing guided surgery, the osteotomy preparation of an immediate implant is just as easy as any other guided surgery. The rigidity of the guide and the guide handles prevent the implant drills from deviating. In the software, we are using the yellow pilot drill path to show us where the future screw access hole will be in our implant crown. By placing the actual pilot back into the osteotomy, taking a film and also just looking at it, we can confirm that we are on the right track as defined by our GALILEOS plan.
A great clinician, Dr. Scott Ganz, once said, “Patients come to us for teeth, not implants.” Which is why immediate temporization is such a “crowd pleaser”! If we can get great primary stability on our implants (more than 35 Ncm of torque), a temporary may be placed on the implant at the time of surgery. This is mainly done on anterior teeth, but due to this patient’s high esthetic demands and lack of parafunction, we decided to fabricate a screw-retained e.max crown and place it at the time of surgery. Here we got about 50 Ncm of torque and placed our implant about 2 mm sub “socket” as measured from the mid buccal. In many cases, the implant itself is much smaller in diameter to the tooth that it is replacing. This results in a gap between the implant and the surrounding bone. In my clinical experience, if the gap is greater than 2 mm I graft around the implant and place a membrane. If this gap distance is less than 2 mm, I allow the socket to heal by secondary intent. In our case, we had minimal gap distance (Fig. 4).
Making an implant temporary is problematic. Making a nice implant temporary around an extraction socket is darn near impossible! Bleeding from the extraction and osteotomy preparation combined with the fact that there is some negative space around the implant can make it difficult to control the extent of a temporary, CEREC or otherwise. However, by using a scan post, margins and bleeding really don’t matter. CEREC reads the top of the scan body like a barcode and then extrapolates the implant position. Another issue of implant temporaries made with acrylic or bisacrylic resin is the fact that some tags or particles of temporary material or cement may become lodged in the open tooth socket, causing infection or failure of osseointegration. Now imagine fabricating a screw-retained restoration that is made and cemented extraorally. In this case, we used a Sirona TSV 3.5 mm scan post in the mouth, a 3.5 mm Sirona TSV TiBase for the screw-retained crown, and an A2 Size 16 e.max abutment block. The case was scanned using the Omnicam and CEREC 4.2 (Fig. 6).
The term “game changer” has been overused and is quite cliché in dentistry these days. But with that being said, no one can deny the impact that the new e.max abutment block is making and will make, in restoring implants. When it was first “teased,” the only benefit I could see with the block was sintering time and the lack of need for an additional zirconia furnace. Boy, was I wrong! First and foremost the e.max abutment block has translucency unparalleled by zirconia or opaqued metal. It gives you the ability to make implant restorations look like teeth. Second is the tissue response. The tissue loves glazed or polished e.max. One thing we strive for in implantology is healthy tissue and lack of inflammation around our implants. Also we hope to retain or even improve the architecture of the soft tissue around immediate implants. We get it all with e.max. In this case, did I do a temporary or a final restoration? The truth is, I don’t know! I like my final implant restorations out of occlusion, and I want the same of my implant temporary restorations as well. This crown will be re-evaluated at 3 months; if the tissue looks good, it will be the final. If I am unhappy about the soft tissue around the crown, I may remove it and make another using the same TiBase and burning out the cement. In Figure 6 we see the proof in our plan! Look at the planned pilot drill path and the resultant screw access! It is in the exact same position. No deviation at all. Many naysayers have felt that guided surgery may not be living up to the claims of 100 micron accuracy and 1-2 degrees of deviation in angulation. You can see in that image that those claims hold no merit (Fig. 6).
The final restoration was torqued to place with 30 Ncm of torque and the screw hex was covered with an endodontic sponge. Opaque flowable and paste composites were used after etching and placement of the bonding agent. Ochre composite stain was used to characterize. Note that the “flash” on the mesial of #30 was removed prior to patient dismissal. This patient walked into my office with a nonrestorable tooth. This patient left with a porcelain implant “temporary,” which is hard to differentiate from a regular tooth- supported crown.
You can’t just buy a bunch of high tech toys, turn them on and expect everything to be easy. There are limitations to materials and machines. There are learning curves to overcome. There are barriers due to patient compliance or anatomy. But with the right training and the right clinical circumstances, guided surgery, in my opinion, is the most accurate, the safest and the most predictable means of placing an implant. And if the implant is placed well, the restoration is not only easy to restore, but can give the patient what he or she wants, a tooth!