Initial situation

A 71-year-old lady presented with a loose upper front retained post crown, and she was concerned this would come out at any moment. The lady had presented for a second opinion because she was unsure of her options having been told she needed to have a tooth removed and would only be able to have a denture to replace the tooth.

The patient reported to feel fit and well but medically was complicated because she suffered from atrial fibrillation and was a long-term warfarin patient. The INR was stable in a range of 2 – 2.5, but clearly we would need to manage the haematological complications this would ensue.

The patient knew that at least one upper front teeth required extraction and, if possible, she wanted a fixed implant solution.

Her remaining dentition were well restored and stable. The periodontal condition was also stable. The occlusal scheme was stable and we looked to replicate this and the corresponding guidance. See Fig 1 and Fig 2.

Treatment planning

The obvious draining sinus and root fracture indicated a clear loss of the buccal plate with relation to the upper left central incisor – the patient also felt that the upper right central incisor tooth was likely to need remedial work in the future so she wished to replace both the upper right and left central incisor teeth with fixed implant retained crowns. Conventional bridgework was not indicated and the patient would only tolerate a removable prosthesis for a short period of time.

We decided to remove the upper central incisors and fit an immediate acrylic denture to remove the acute infection. We reassessed at 8 weeks following soft tissue closure, with a CBCT scan to evaluate the hard tissue healing post extraction and this confirmed the need for some form of hard tissue augmentation procedure to enable successful implant placement. See Fig 3, Fig 4 and Fig 5.

With the loss of the buccal plate it was agreed we needed a block grafting procedure and to prevent multiple surgical interventions, we discussed using the bonering technique which would enable simultaneous block grafting and implant placement. We also discussed using an allograft to prevent the need for a second donor site surgery and the complications this could entail – especially given the patient’s medical history and compromised clotting pathway.

Following successful implant placement and integration of the allograft bonering (botiss maxgraft® bonering) we would then restore with screw retained individual crowns.

Surgical procedure

At 10 weeks post-extraction the implant surgery was performed. A large flap with remote crestal incision across the pontics and vertical releases distal to adjacent teeth exposing a large defect of the ridge in the upper left central incisor was raised with periosteal relieving incisions to allow passive tension-free flap closure over the grafting site Fig 6.

The bonering technique was performed to allow simultaneous implant placement and allogenic block grafting procedure. It began with:

  • a primary osteotomy site preparation,
  • then trephine Fig 7,
  • then planate to smooth graft site Fig 8,
  • allograft bonering adjusted to correct length Fig 9,
  • block passively fitted in situ Fig 10,
  • final osteotomy site preparation and placement of implant fixture in situ of graft Fig 11,
  • a layer of xenograft (botiss cerabone®) with a low substitution rate is applied over graft and area and adjacent implant for a conventional guided bone regeneration technique Fig 12,
  • a single layer of resorbable membrane (botiss Jason® membrane) was applied to cover the ridge augmentation and prevent soft tissue inclusion Fig 13,
  • the surgical site was then closed with a series of passive tension-free prolene® (Ethicon) sutures with flap advancement to prevent wound dehiscence Fig 14,
  • periapical radiograph to show implant placement and graft approximation Fig 15,
  • the sutures were removed 2 weeks later with uneventful healing Fig 16,
  • the surgical site was then allowed to heal and integrate for the next 4 months prior to beginning the restorative phase Fig 17.

Prosthetic procedure

Four months after implant placement the implants appeared well integrated with excellent soft tissue healing. A fixture level iTero (Align Technologies) scan was taken to fabricate temporary crowns Fig 18. The temporary crowns were used to develop optimal emergence profiles for the definitive crowns Figs 19, 20. 4 and 5mm soft tissue punches were used to adjust the soft tissue to allow fitting of the temporary crowns Figs 21, 22, 23. A periapical radiograph of the temporary crowns was taken to check seating and bone levels Fig 24.

Final result

Approximately 6 weeks later, once the soft tissue emergence profile had developed a natural appearance, the definitive crowns were made Figs 25, 26. The patient was extremely happy with the final aesthetic and functional outcome Fig 27. The postoperative radiograph shows excellent stable bone levels and the allograft appears to be native bone in appearance Fig 28.

Conclusion

Clearly the use of an allograft bone material as an alternative to harvesting a block graft in a medically compromised patient in this case was a distinct advantage. The ability to combine implant placement and block grafting into a single visit again reduced invasiveness and healing times and consequently overall treatment time by approximately 2 months.

The soft tissues were periodontally sound with nil probing depths greater than 2mm around the fixtures and sufficient hard tissue support.

The patient was extremely happy and confident with her new front teeth and an excellent clinical outcome was achieved.


Dr Ross CuttsAbout the author

Dr Ross Cutts is the Principal Dentist at Cirencester Dental Practice and Stow-on-the-Wold Dental Practice

www.cirencesterdentalpractice.com

 

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