Dr. Giancarlo Romagnuolo Roma, Italy From planning to surgery: a totally digital working flow for Leone implants placement Keywords guided surgery, 3D implant planning, single missing tooth, delayed immediate postextraction implant placement, GBR In the last 20 years dentistry has dramatically changed due to new knowledge, to the development of materials and techniques, even thanks to technological and digital progress. Implant dentistry, till few years ago, was aimed to place titanium implants in maxillary jaws in order to restore missing teeth or stabilize full-arch prostheses having osseointegration as the only success criterium. Now there are some other success criteria: white esthetics (prosthesis), pink esthetics (soft tissues) and grey esthetics (bone stability) have been introduced as new concepts. Based on such considerations it is clear that three-dimensional implant placement is of utmost importance. In recent years from manual free-hand implant placement with open flap surgery we have passed to planning procedures aided by 3D diagnostics (CT scan and CT Cone Beam), so using surgical templates for guided surgery and, if possible, using flapless technique. Normally the working flow includes impression taking to fabricate dental study models and then diagnostic waxing. Once this is approved, it is turned into a radiographic stent by the dental technician and given to the patient so that he could wear it during the three-dimensional radiological exam. The originality of this article resides in showing a clinical case performed with a totally digital working flow (SICAT OPTIGUIDE technique). We have designed a virtual waxing onto the digital model obtained from the intra-oral optical scanning with CEREC (Sirona) system. The patient has been scanned, during the same session, via CT Cone Beam system (GALILEOS Sirona). The matching of the 3D optical model with the 3D radiographic model gives as an output one only high-precision threedimensional digital model. From the software library we have selected the implant type and planned its placement, visualizing bone tissue, soft tissues and prosthetic crown (fig. 1). Fig. 1 1
The digital project is sent via web to SICAT Sirona company, that gives back the surgical template within few days; the template, made with high-precision technology, already includes LEONE sleeves. Such sleeves, made of ultra-polymer and specific for Digital Service LEONE guided system, allow using Zero1 drills to make a one-step osteotomy. Digital Service LEONE system is present in GALILEOS Implant software starting from 1.9.2 release and is included in the corresponding database. CLINICAL CASE Presented is the case of a 45-year-old female with local sintomatology on tooth 24; she reports past acute episodes. The 24 element was endodontically treated, with endodontic post in false path and metal-ceramic crown; moreover it resulted painful to mastication, palpation and percussion, mobile (with 2-degree mobility) and we could observe swelling on buccal gingiva and wide peri-apical area of bone rarefaction (figs. 2, 3). Fig. 2 Fig. 3 The patient did not want to treat the tooth again since she had been treated twice in another office and she was no more motivated to save the tooth. Then we decided to extract the tooth. At the time of tooth extraction the alveolar buccal bone plate was absent. Four weeks after the extraction in the same session we performed intra-oral scan (fig. 4), then designed the virtual diagnostic denture (figs. 5, 6), made the intra-oral radiographic evaluation (fig. 7) and the TC Cone Beam exam (fig. 8); finally we matched the two digital data (fig. 1) and decided implant type and position. As you could appreciate from the pictures, 4 weeks after the extraction the site presented insufficient bone availability, showing in particular absence of buccal bone wall. The treatment plan included, despite the surgical guide, the opening of a surgical flap in order to contemporarily regenerate the buccal bone plate. Fig. 4 Fig. 5 Fig. 6 2
From planning to surgery: a totally digital working flow for Leone implants placement Fig. 7 Fig. 8 From the software library we selected the implant, that was a LEONE 3,3 x 10 mm implant. Its position was planned according to the prosthesis. The procedure was done in front of the patient, who took part and understood the steps. Then the planning (fig. 9) was sent via web to SICAT, that fabricated the surgical guide including the LEONE sleeve, specific for Zero1 one-step drill, and sent it to our dental office (figs. 10, 11). The template guided the implant placement accurately to the position we had previously planned and is not synonymous of flapless surgery. In fact in the present case we opened a surgical flap despite the guide. Fig. 9 Fig. 10 Fig. 11 3
We checked precision and fitting of the guide in the oral cavity (figs. 12, 13). Fig. 12 Fig. 13 The Zero1 drill offers numerous advantages. It has a short drilling portion, with a high-penetration design: such properties reduce the risk of bone heating, allowing one-step osteotomy, whatever the implant diameter. Moreover inserting the drill already coupled with the sleeve allows the reduction of its vertical size: this way during surgery it is possible to easily do intra-oral operations without excessive opening of patient mouth (figs. 14, 15). Fig. 14 Fig. 15 The surgery was done 16 weeks after the extraction. Due to the absence of bone plate we opened a full-thickness flap to make bone regeneration, in order to visually verify the correct position of the implant accurately to what previously planned. 4
Figs. 16, 17 - Tissue status just before surgery Fig. 17 After administration of anesthesia we opened a full-thickness flap without releasing incisions to keep as intact as possible tissue vascularization. Once seated the guide we made a one-step osteotomy with Zero1 drill, under irrigation with 4 C physiological solution (fig. 18). Fig. 18 The implant was placed with its specific carrier for guided surgery, after sleeve removal (figs. 19, 20). Fig. 19 Fig. 20 5
The bone defect was regenerated with deproteinized bovine bone and VEGF (Vascular Endothelial Growth Factor)-doped fibrin glue (figs. 21, 22). After the placement of a Standard GH3 mm healing cap, we applied PTFE suture and radiographically checked the situation (fig. 24). Fig. 21 Fig. 22 Fig. 23 Fig. 24 After 3 months we passed to prosthetic stage, manufacturing a provisional crown in acrylic resin. First we selected the proper abutment and then we tried it onto the implant: the try-in confirmed how the implant planned position had been respected, being the abutment in the middle of the prosthetic crown and equidistant from adjacent teeth (fig. 25). Fig. 25 6
A resin-made provisional crown was fabricated directly onto the abutment, thus achieving an integrated prosthetic element that was connected to the implant without using any cement (figs. 26, 27). Figs. 26, 27 - Provisional crown at delivery time Fig. 27 We can appreciate the soft tissue conditioning, with buccal convexity and compliance with a correct parabola for a good maturation of interdental papillae (figs. 28-30). Fig. 28 - Concave profile of buccal soft tissue before implant placement Fig. 29 - Convex profile of buccal soft tissue after provisional crown delivery Fig. 30 7
The clinical control made six months after the prosthetic delivery showed excellent tissue healing (figs. 31, 32). Fig. 31 Fig. 32 The possibility to make diagnosis, treatment planning and surgical guide through a totally digital flow opens up new horizons to the clinician and puts the patient in a context of progress that s in keeping with his life in modern society. The patient receives in the same session a complete answer to whatever refers to diagnosis and treatment plan, thus getting a strong message of high-technology and efficiency. The Zero1 drill and the screwless LEONE implant-abutment connection perfectly fit into this image. The Zero1 drill allows a single-step osteotomy with the highest results in terms of precision and reduction of tissue heating. The screwless implant-abutment connection of the LEONE implant system simplifies both surgical and prosthetic procedures and allows long-term maintenance of the esthetic and functional results. The goal is planning as much as possible the treatment phases with the lowest number of steps, producing predictable, repeatable and affordable high-quality results. 8