PMC6885791_01
Preoperative clinical and radiographic views: (a) buccal aspect, (b) palatal aspect, (c) periapical radiograph of the right central incisor, (d) periapical radiograph of the left first premolar.
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The prosthesis was both functionally and aesthetically inadequate, and the patient complained of gingival swelling, bleeding, and food impaction at the site of the implants (Figures 1(a) and 1(b)). Standard periapical dental radiographs taken to assess periodontal status of the right central incisor (Figure 1(c)) and left first premolar (Figure 1(d)) adjacent to the implants showed significant bone loss on the mesial aspect of the roots.
Computed tomography scans showed the implant in the region of the central incisor inside the incisive canal (red arrow) and the three-dimensional bone loss around the implants, which were osseointegrated only in the apical portion with the remaining surfaces being covered by radiopaque biomaterial particles encapsulated in the soft tissues (green arrows).
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The remaining surfaces of the implants were covered by radiopaque biomaterial particles encapsulated in the soft tissue, and the implant in the region of the central incisor was inside the incisive canal (Figure 2).
The first intervention: (a) clinical view of the implants and grafting material after flap elevation and (b) the bone ridge after removing implants and cutting the crowns of the adjacent teeth.
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The first surgical stage was aimed at removing the implants and preparing the bone ridge and soft tissues for augmentation procedure (Figures 3(a) and 3(b)).
After two months of uneventful healing: (a) clinical view and (b) computed tomography scans showing the three-dimensional ridge defect and height of the available bone (5 mm) in the implant sites indicated by the template radiopaque markers.
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After two months of uneventful healing (Figure 4(a)), wax-up of the prosthetic restoration was made on diagnostic/study mounted casts in order to identify the ideal three-dimensional position of the implants. Postoperative computed tomography scans (Figure 4(b)) showed residual bone height of 5 mm and a three-dimensional bone defect of approximately 10 mm at the planned implant sites, corresponding to the radiopaque markers on the template.
The second intervention: (a) the full-thickness trapezoidal flap, (b) buccal view of the vertical defect in the anterior maxilla, (c) the implants protruding 10 mm from the top of the crest of the bone; (d) particulate composite bone graft in place and e-PTFE membrane fixed on the palate, and (e) e-PTFE membrane fixed over the grafted area with buccal titanium miniscrews.
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A full-thickness trapezoidal flap (Figure 5(a)) with wide buccal base and palatal pedicle was performed in order to ensure good vascular supply to the grafted area and tension-free complete closure over the augmented ridge. The bony defect, as measured with two crossed-calibrated periodontal probes, extended 10 mm from its most apical portion to a line connecting the cementoenamel junction of the adjacent teeth (Figure 5(b)). Two implants (MKIV 4 x 15 mm, Branemark System , Nobel Biocare), protruding for about 10 mm from the top of the bony crest, were placed in the three dimensionally corrected position using the radiographic/surgical template (Figure 5(c)). The autograft was enhanced with a second layer of solvent-dehydrated mineralized cancellous bone allograft (Puros  allograft, Zimmer Dental) (Figure 5(d)). The membrane was stabilized over the augmented area with two additional buccal titanium self-tapping screws (Figure 5(e)).
At the 9th month re-entry: (a) clinical view of the regenerated area, (b) alveolar crest regeneration after flap elevation and membrane removal, and (c) flap sutured after free connective tissue graft and first temporary bridges.
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At the surgical re-entry after 9 months of uneventful healing (Figure 6(a)), the miniscrews and titanium-reinforced e-PTFE membrane were removed. Complete filling of the bony defect was observed with a hard regenerated tissue clinically similar to bone, covered by a thin layer of firm connective tissue (Figure 6(b)). The flap was apically repositioned to restore the vestibular depth lost during the second surgical stage, and a free connective tissue graft, harvested from the palatal mucosa, was performed to improve the aesthetics of the soft tissues (Figure 6(c)).
Definitive cemented prosthetic restoration in porcelain-fused-to-metal: (a) clinical view and (b) periapical radiograph.
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The regenerated bone after 14 years of loading, during surgery to treat the peri-implantitis lesions on the buccal surface of the implants and after extraction of the right central incisor: (a) clinical view, (b) periapical radiograph of mesial implant, and (c) periapical radiograph of distal implant.
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