Dealing with complications

The next case involved a twenty-year-old patient with missing anterior teeth due to a car accident. The patient had hard and soft tissue deficiencies in the upper anterior region.

The speaker outlined a four-stage treatment plan:

1. Allogenous bone block graft in the maxillary frontal area combined with GBR using Bio-oss® and Bioguide®. Temporisation achieved with an Essex appliance (in place until stage 3)
2. After 6–7 months, placement of two two-piece implants with rough surfaces
3. After 4–6 months, fabrication of a three-unit fixed provisional prosthesis
4. After 2–4 weeks, delivery of the final zirconia bridge

The operation was performed according to current treatment guidelines, and each step is outlined in figures 11–14.

Healing was uneventful, although a lack of attached gingiva and a decrease in vestibular depth were observed in the area (as would be expected). The six-month post-op CBCT showed a gap between the bony bed and the block graft. When reopening, most of the bone block had become granulated tissue and no ossification was present.

Reflecting on this outcome, the speaker stated that the following factors may have been reasons for failure:

• the inadequate amount of keratinised gingiva should have been corrected before the block grafting was planned
• a combination of improper fit between the block and recipient bed, insufficient number of screws to prevent micromovement and excessive thickness of the blocks used
• there may have been pressure exerted over the graft during function with mobile soft tissues
• an autogenous bone block could have produced better results than an allogenic block
• the graft may have been infected

A vestibuloplasty using Mucograft® was then performed (fig 15–16). An autogenous bone block is planned, after which the original prosthetic treatment plan will be carried out.