This is the seventh video from my Dental Excellence Video Series. In this video I share with you the different tooth preparation guides and stents that I use in my dental practice.
Remember. You can do this kind of dentistry and that beautiful dentistry with precise fit and occlusion is not just for the gurus!
After complete healing, the alveolar ridge appeared favorable for a flap-less implant placement approach. This can be a challenge to position the implant platform at the ideal level. If the implant is positioned too shallow, there will be insufficient room to create a proper emergence profile and crown form. If the implant is too deep, it may be a risk for future recession or inflammation.
I was very careful with measurements made clinically from the existing gingival margin and the new planned gingival margin as well as checking with radiographs. Using a computer-generated guide is another option for these cases, but will still require good clinical judgement.
The implant was positioned with the platform 3 mm from the future gingival margin to accommodate a favorable emergence profile. It is important to note that the interproximal bone must be modified to create space for the future restoration; otherwise, it may be a challenge to seat the restorative abutment and there is possible risk of developing bone necrosis due to excessive interproximal pressure. (See radiographs)
The gingival recession on the adjacent central incisor #8 (FDI #11), was improved by a semi-lunar coronally advanced flap.
After the implant has osseointegrated, it is time to shape the abundant soft tissue from that of a circular healing abutment to that of a triangular tooth form. The provisional restoration is fabricated with a sub-gingival profile that will create tissue support and an ideally positioned height of contour to move the gingival margin to the desired level.
After a couple of months, the tissue form created by the provisional restoration can be duplicated by using a custom impression coping during the impression procedures. The final crown should follow these sub-gingival contours to maintain this soft tissue form.
The restorative phase was completed with a custom cast gold abutment and a cemented PFM crown. The crown form was slightly flatter at the mesial line angle than the provisional restoration and we can see the change in the soft tissue form. Overall, the treatment sequence insured a predictable outcome for this patient.
In the last blog I presented a patient that had a non-restorable maxillary central incisor. She was treated with an immediate post-extraction implant placement and a custom provisional crown to immediately support the soft tissues.
Unfortunately, we can not always provide this form of treatment to all patients. When should we separate treatment into phases?
I had mentioned that we must take into consideration the shape and dimensions of the labial bone, the existing soft tissue profile and the amount of apical bone.
Immediate post-extraction implant placement requires ideal bone volume. The immediate implant is anchored into the apico-palatal bone. If the bone is this area is compromised, then implant stability may not be achievable. In addition, the bone on the facial supports the soft tissue profile. Thin bone or large dehiscences are a risk for future gingival recession. A patient with inadequate facial alveolar bone should not receive an immediate implant.
This next patient I will present also had a non-restorable failing maxillary central incisor. As a teenager, this tooth was traumatized during a sports injury. It was endodontically treated and crowned. Ten years later, this tooth required apical endodontic surgery. The patient is now 40 years old, and presents with a fistula at the apex of the central incisor. The patient consulted with members of our team, including an endodontist. After reviewing his options, he requested to have this tooth replaced with a dental implant.
From the clinical exam, we can determine that the soft tissue profile for this failing tooth is more coronal than the adjacent central incisor, which has slight gingival recession.
We have a very favorable soft tissue position prior to surgery, so soft tissue augmentation may not be necessary.
Further clinical evaluation we note a fistula at the apex of #9(FDI #21). On the radiographs, we determine that there is a peri-radicular lucency that extends to the floor of the nose. Since this is the area that I depend on for implant stability, it is unlikely that I can predictably place the implant at the time of extraction.
So how should we manage this site? How do we extract, debride and graft the alveolar ridge?
My approach follows a sequence of steps, intended to both correct and maintain the alveolar dimensions.
After extraction, I observed that the crestal bone on the facial aspect of the socket was intact and at a favorable level. However, the lesion had resorbed the overlying bone in the apical zone.
So to gain good access to the lesion, I made a C-shape incision around the apical fistula. In addition, this allowed access for placement of the bone graft and membrane. By avoiding flap reflection in the crestal half of the ridge, I was able to maintain the blood supply to the alveolar facial bone. The ridge was grafted with allograft bone and the socket closed with an epitheliazed graft.
In the next blog, we will discuss implant placement and restoration.
Dr. Stephen Phelan graduated from the University of Toronto, Faculty of Dentistry in 1992. He has lectured locally and internationally on the subject of dental implants, occlusion, esthetic and restorative dentistry.
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