Every picture tells a story: implant fracture

Jan 15, 2019

Could this fractured implant have been avoided? Eddie Scher explains the importance of knowing your implant system’s requirements

Figure 1: Fractured head of implant. Probable cause: the hex was wrongly positioned when the screw was tightened

This patient was referred to me when the abutment in her implant had come loose. This was a cementable implant crown, and it appeared that the crown had been affixed with permanent cement.

The patient requested to go to a restorative specialist local to her home to perform the treatment I recommended. That dental surgeon asked to borrow from me an appropriate torque wrench and screwdriver for this particular system.

I remember it being very strange when the specialist called me to say that everything had gone very well, but he had only placed the post back with finger-tight tightness and not used the torque wrench. I commented to him that the protocol was to torque this particular implant screw up to 35Ncm, and the patient will probably have the abutment come loose very quickly.

Within a couple of weeks, the patient was referred to me. I believe this X-ray tells its own story (Figure 1). Unfortunately, the patient had to be told that the implant was now a failure. The only solution would be to remove it, and once again consider her options regarding the gap.

Figure 2: Piezosurgery tip, selected to remove the bone from around the implant

The patient decided that she definitely wanted another implant. Under strict sterile conditions in the practice operating theatre, we gently and carefully removed the implant using piezosurgery (Figure 2) (Vercellotti et al, 2000).

We selected the ideal tip to gently remove the bone around the implant. The insertion tool was then placed back into the implant, allowing us very gently to unscrew the implant for its final removal (Figures 3 and 4).

Figure 3: Implant insertion tool placed so as to unscrew the implant gently for its final removal

Figure 4: Implant removed gently with Piezosurgery, and minimal bone loss

Following removal, the whole area was very gently curettaged and debrided. Decortication was then performed using a very fine diamond-pointed piezosurgery tip, made especially for this procedure.

We then performed a socket preservation procedure using a demineralised freeze-dried bone xenograft and platelet rich plasma (Marx, 2004). It was then closed up with vicryl sutures (Figure 5). After a suitable healing period of four months, we surgically placed a new osseointegrated implant (Figures 6 and 7), and after another three month healing period we proceeded to restoration. This was done first with a provisional plastic crown just out of occlusion. This allowed us to practise our concept of progressive bone loading (Misch, 1995), and also allowed the patient to criticise the shape, size, colour, position, projection, and phonetics. The final result in gold and porcelain was then placed in occlusion.

Figure 5: Socket preservation procedure, with demineralised freeze-dried bone xenograft and PRP

Figure 6: New implant in place

Figure 7: New implant exposed with healing collar three months after its insertion

Key Points

  • The dental surgeon must always have a full understanding of the particular implant system that he or she is working with
  • This is especially the case with the torque tolerances of different applications: e.g. screwing an abutment on to an implant, or a crown or overdenture on to an abutment
  • The dental surgeon should always take an x-ray to make sure that the hex of the abutment is located properly within the implant. This is absolutely essential when the implant is subgingival, as in the present case.
  • When solving a problem in implant dentistry, one should always take it stage by stage, and not try to ask for more than one miracle at a time. In this particular case, we might have tried to place an immediate implant in this region, but we chose to regrow the bone in the first instance, giving the replacement implant a better chance of survival
  • In this case, we chose to go to a provisional crown rather than to a definitive crown immediately, as this allowed us total control of our prosthetics. We were able to make sure that the occlusion was correct in this case.

Aims and objectives

The aim of this article is to demonstrate how to remove a fractured implant and successfully replace it with another.

The reader will:

  • Understand the importance of using an implant system correctly
  • Learn a technique for socket preservation
  • See how to approach subsequent implant placement

References

Marx RE (2004). Platelet-rich plasma: Evidence to support its use. J Oral Maxillofac Surg 62: 489-96

Misch C (1995). Progressive bone loading. Dent Today 14; 80-83

Vercellotti T et al (2000). Piezoelectric surgery in implantology: A case report – a new piezoelectric

ridge expansion technique. Int J Periodontics

Restorative Dent 20; 359-365