Larger implants possible at grafted tooth-extraction sites
MedWire News: Grafting to augment tooth-extraction sites does not improve the clinical performance of subsequent implants, report Italian researchers.
However, it does allow the use of larger implants and less augmentation during implant placement, they say.
The quality and quantity of alveolar bone is central to the long-term stability of implants in the treatment of a single missing tooth. Because the alveolar ridge undergoes resorption and atrophy following tooth removal, it is essential to preserve the alveolar crest to enhance the surgical site before implant fixation.
To examine the necessity and success of augmentation at implantation, Bruno Orlando, from the University of Pisa, and colleagues randomly assigned 40 patients requiring a single tooth extraction and subsequent implant-supported restoration to receive extraction with or without the grafting of corticocancellous porcine bone.
After 7 months, implants were inserted into each of the extraction sites. Metal-ceramic rehabilitation was then used to submerge and load the implants 4 months subsequently.
The patients were followed up for a maximum of 3 years, which included assessment for implant diameter and length, the need for further augmentation at implant placement, implant failure, and marginal bone level changes.
The most common reason for dental extraction was dental fracture, which was reported in 20 patients, followed by severe dental caries in 11 teeth, and endodontic failure in nine cases.
The results, published in the Journal of Periodontology, show that during implant placement, three implants in the grafted group, and 10 in the non-grafted group required additional augmentation, which was a statistically significant difference.
Patients who underwent grafting also received implants of greater length and diameter than those in the non-grafted group, and there was a significant relationship between treatment group and implant length and diameter.
However, only one implant (in the grafted group) failed, and was subsequently removed for mobility after 24 months of loading. The cumulative implant survival rate at the 3-year examination reached 95% in both patient groups.
Radiographic examination showed that all remaining implants were successfully osseointegrated, and there were no significant differences between the groups in terms of marginal bone changes.
The team says: "It can be concluded that implants placed into sites subjected to ridge preservation exhibited a clinical performance similar to implants placed into non-grafted sites with respect to implant survival and marginal bone loss."
However, "extraction alone may lead to unpredictable healing patterns in which the remaining ridge does not often allow for an aesthetic and functional solution without the aid of an additional bone augmentation procedure simultaneously with implant placement."
By Liam Davenport