Dr Fábio Vidal
Ortho-perio-implant interdisciplinary approach to a complex rehabilitation case: 13 years follow up.
Fábio Vidal – Rio de Janeiro, Brazil.
Case description: A female patient, 62 years old was referred for treatment by her general practitioner due to advanced periodontal disease and failing dentition. The 1st appointment was in June 2004.
The patient´s main complaint was the mobility of several teeth and poor esthetics and function.
Clinical and radiographic evaluation showed (Fig.2 – images #1 and #2):
– Unstable occlusion due to the absence of the molars;
– Several sites with PPD and CAL≥6mm, BOP>80%, VPI>90%;
– Grade 2 mobility in the upper dentition and lower incisors and grade 1 mobility in the lower canines;
– Poorly restored teeth and carious lesions involving the roots of many teeth.
Medical aspects: patient had severe refractory hypertension (160x90mmHg) and moderately controlled type 2 diabetes (150mg/dL and glycated hemoglobin 7.5%) treated with metformin and diet.
Patient was non-smoker and reported no other medical condition, being considered ASA II (New Classification of Physical Status. Anesthesiology. 1963;24:111).
Periodontal diagnosis: Severe generalized chronic periodontitis (AAP-1999).
Panoramic radiograph at the 1st appointment (Fig.3 – image #3) showed advanced bone loss at the upper dentition, carious lesions and failed restorations in the lower pre-molars. At the time of the 1st appointment (june 2004), cone beam CTs were not available in Brazil and the patient could not afford to pay for a medical CT. Therefore, treatment plan was based solely on clinical parameters and panoramic radiograph. Panoramic radiograph evaluation showed that the patient had enough bone height to consider implant placement in the mandible and in the maxilla without major bone augmentation procedures.
Treatment plan:
After a comprehensive oral/dental assessment and a consultation with the patient´s attending physician, the different treatment options were presented to the patient, who demonstrated her will to save as many teeth as possible and her unacceptance to wear removable prosthesis. Duration of the treatment was not a problem to the patient. Therefore, the following treatment plan was presented and accepted by the patient:
1. Basic periodontal therapy: to reduce the infectious burden and allow the maintenance of the lower anterior segment.
2. Extraction of the failing maxillary dentition with immediate placement of 6 implants in the residual bone, aiming to support a 12 teeth, fixed, porcelain fused to metal prosthesis.
3. GBR to preserve/augment the bone if/where needed.
4. Immediate provisional denture in the maxilla.
5. Extraction of the lower premolars considered unrestorable.
6. Partial removable prosthesis in the mandible to allow the restoration of the vertical dimension of occlusion.
7. Orthodontic therapy to correct the position of the lower anterior segment, and consequently, the maxillomandibular relation. Two 2 osseointegrated dental implants were planned to be placed in the position of the 1st molars and used as ancorage (Weber et al., 2017).
8. Two partial fixed prostheses to replace the lower posterior segments.
Pre-surgical appointments:
Previously to surgery, impressions were taken and the models mounted in semi-adjustable articulators in order to prepare the provisional transition prosthesis and to plan the ideal position of the final prostheses and, consequently, of the dental implants. All the treatment plan was based in the concepts of prosthetically driven implantology (Annibali et al., 2009).
Periodontal therapy: Periodontal treatment followed the recomendations for treatment of chronic periodontitis with advanced loss of periodontal support (AAP – 2000) and for the management of periodontitis associated with systemic conditions (AAP-2000). Ultrasonic scalers and curettes were used to remove supra and subgingival calculus; sodium bicarbonate jet prophylaxis was done to remove biofilm and stains and the patient received the necessary information in order to be motivated to maintain proper dental care at home. No antibiotics were prescribed , in accordance with the AAP position paper recommendations (AAP-2000). Two months after the completion of the periodontal therapy, PPD, CAL and BOP were reassessed and showed that the patient responded to treatment, with complete resolution of the inflammation.
First surgery
The 1st surgery was done with intravenous sedation assisted by an anesthesiologist, in order to allow better stress control and to make the procedure more confortable to the patient (Craig et al., 2000).
In the same appointment, 8 teeth were extracted, sockets thoroughly debrided and residual bone crest was cleaned and leveled (Fig.4 – images #4 and #5). 6 conical dental implants with external connections were placed according to the positions previously planned (central incisors, canines, 2nd premolars). A surgical stent was used to help achieve the best 3D position possible in the residual bone. Due to a large defect at the right canine, implant distribution was changed and 1 implant placed in the lateral instead. GBR was done to correct bone defects using autologous bone chips, DBBM and collagen membranes (Darby et al., 2009).
Immediate post op and re-evaluation after 1week:
Primary closure was achieved and the provisional adjusted and relined because the patient refused to remain toothless. Patient was instructed to use the provisional as little as possible.
Prescription: Amoxicilin 500mg 3x/daily for 1 week;
Meloxican 7.5mg 2x/daily for 5 days;
Chlorhexidine rinse 0.12% 2x/day for 14 days.
Acetaminofen 750mg in case of pain.
After 1 week, patient returned for re-evaluation and reported mild pain, controlled with medication and discomfort when using the provisional due to the edema. The surgical site healed uneventfully (Fig.5 – image #6).
Sutures were removed after 14 days and the provisional relined with soft relining material.
3 months re-evaluation:
After 3 months, the patient returned with a control radiograph showing the implants in position (Fig 6 – image #7). Implants were placed following reverse planning, trying to achieve the best 3D position possible and, at the same time, to avoid major bone grafts. By this time, the right canine had already received endodontic treatment and the lower premolars had been removed. Maxillomandibular relation was class III (Fig.6 – image #8). Thus, the orthodontic treatment and the second surgery were planned.
Ortho planning + 2nd surgery:
Two implants were planned in the position of the future 1st molars (Fig. 7 – image #9). The correct position was determined based on the orthodontic set up, that estimated the final position of the canines after orthodontic treatment. The orthodontic planning took into consideration the final position of the maxillary teeth that was determined by the prosthodontic wax up.
Orthodontics: After osseointegration of the lower 1st molars, 2 screw-retained provisional crowns were placed and the implants used as anchorage to the orthodontic mechanics (Fig. 8 – images #10 and #11). Also, provisionals were used to restore/maintain vertical occlusal dimension.
Fixed full-arch provisional: Six months after the 1st surgery, patient came back for re-entry surgery in the maxilla. Right after soft tissue healing , a screw-retained, full-arch, acrilic provisional was prepared, allowing to fulfill the patient´s wish to replace the removable prosthesis (Fig. 9 – image #12). The provisional was used to condition the soft tissue with the dynamic compression technique (Wittneben et al., 2013) and to serve as a reference for the orthodontic movement.
During the orthodontic treatment the provisionals needed periodic adjustments to allow the correction of the cross-bite (VOD was increased temporariliy to let the anterior segment move lingually and then restored to a more physiological position again).
As soon as the orthodontic movement was finished and the canines were in position, the last 2 implants were placed in the 1st pre-molars position.
Final restorations:
After osseointegration of the 1st premolars (3 months), the impressions were taken and mounted on a semi-adjustable articulator. A 12 teeth PF-1/PF-2 prosthesis (Misch classification, 1989) was designed for the upper dentition. Because 2 implants had the access to the screw too close to the incisal edge the prosthesis needed to be cement-retained to avoid mechanical failure of the ceramics. Therefore, the abutments were prepared and proved (Fig. 10 – images #13 and #14) to guarantee that the cement line would be supragingival allowing better removal of the excessive cement. The patients low lip line, together with the possible risk factors for peri-implantitis present in this case (history of periodontitis and diabetes) (Fiorellini and Nevins, 2000; Moy et al., 2005; Ferreira et al., 2006) contributed to the decision to define a supragingival cementation line, this way avoiding another recognized risk factor, excess cement (Linkevicius, T. ITI treatment guide vol. 7).
In the mandible, 2 screw-retained fixed bridges with 3 teeth each (two premolars and one 1st molar) were done.
After the frameworks were proved, the feldspathic porcelain was applied (Fig. 11 – images # 15, #16 and #17) and one appointment scheduled to prove and adjust the 18-element prosthetic work (Fig. 12 – images #18 and #19; Fig. 13 – images #20, #21 and #22). After all the adjustments, the prostheses were concluded (Fig. 14 – image #23). The upper prosthesis was cemented with a non-eugenol provisional cement to allow the removal of the prosthesis, if needed.
Patient was instructed regarding the need to comply with the domestic measures of oral care; taught how to use the interproximal brushes and superfloss and scheduled for a review appointment after 1 week to assess if there were any complaints.
At the review appointment, the patient reported being fully satisfied with the prostheses and was able to perform proper plaque control at home. Thus, a maintenance protocol was established, in which, 4 appointments per year were planned, in order to follow up with the case.
Due to personal reasons, the patient was unable to keep strictly with the program, but managed to return 2-3 times per year. In every recall appointment, the patient medical and dental parameters were assessed and the importance of excellent plaque control reinforced.
With approximately 7 years of function, micromovements were noticed during a recall appointment, suggesting the “failure” of the provisional cementation. Therefore, the prosthesis was carefully removed with a pneumatic remover and a new cementation was done, this time with zinc phosphate. Periapical radiographs taken at the time (Fig. 15 – image #24) showed stable bone levels, with minor remodelling.
After 13 years of function, hard tissue remain stable and soft tissue presented minor recession in some areas, however, maintaining a healthy condition (Fig. 16 – image #25 and Fig. 17 – image #26). No biological or mechanical complications were noted throughout the 13 years of follow up.
Final considerations (Fig. 18 – Image #27): Although both the patient and the dental team were satisfied with the results, we would have a different approach today. First, we would bring the planning phase to a digital format, using CBCTs and planning software to establish the best 3D position for the case. Digital tools would also help with the orthodontic planning. Regarding the surgery, we would probably use a fully, or partially guided approach, with the aid of 3D printed templates/surgical guides in the maxila and in the mandible. This approach would allow us better accuracy than traditional acrylic guides (Vercruyssen et al., 2014) and maybe allow us to design a screw-retained prosthesis for the maxilla. The advantages of screw-retained prosthesis are well described in the literature (Wittneben et al., 2017), and are more significant specially in patients with higher risk for peri-implantitis, that require more intense supportive care after delivery of the final restoration. Anyhow, despite of the limited diagnostic and planning resources available at the time , the case was successfull, mostly due to the compliance of the patient; the favorable implant positions and the cleansability of the prostheses.
