Roughened surface implants keep bone loss to a minimum
MedWire News: Research suggests there is minimal marginal bone loss 5 years following implant placement when using the Astra Tech Implant System with a TiOblast surface.
Denis Cecchinato (Institute Franci, Padova, Italy) and colleagues included 133 patients in a retrospective, single-center cross-sectional study. Each patient had attended a follow-up appointment at a dental clinic in 2007, had implants (Astra Tech Implant System with a TiOblast surface) that had been in place for more than 3 years, and had high-quality radiographs taken at that time.
All of the patients were recalled and had further radiographs taken to enable measurements of bone loss over 5 years of follow up. Patients who had more than one implant site exhibiting bone loss of greater than 0.5 mm were recalled for clinical examination.
The mean age of the overall group was 51 years and approximately 50% were female. The 133 patients in the study sample had 407 implants; in 31% of cases implants were placed in the mandible and in 56% of cases in the maxilla, while the remaining cases had implants in both the mandible and maxilla.
The mean marginal bone loss for the entire group was 0.2 mm - well within the accepted margins for successful implant placement. Less than one-third (30%) of patients presented with marginal bone loss greater than 0.5 mm, while less than a fifth (19%) had bone loss greater than 1 mm, and less than one in 10 (8%) had bone loss greater than 2 mm.
Among the 40 patients who experienced bone loss, the average loss across all implant sites was 0.88 mm, although the average amount lost per affected site was 2.1 mm.
For the 30 patients who returned for clinical examination, there did not appear to be any correlation between bone loss and probing pocket depth, a marker of periodontal disease.
Writing in Clinical Oral Implants Research, the authors conclude: "This retrospective cross-sectional study documented that the vast majority (70%) of the subjects included exhibited no bone loss during a follow-up period of close to 5 years.
"In addition, in the same interval, the majority of the implant sites (>80%) remained without signs of marginal bone loss. Only 8% of subjects and 4% of implant sites presented with marginal bone loss >2 mm."
They continue that "in the 'diseased' subjects that returned for a clinical examination, the prevalence of sites with advanced bone and deep pockets was small."
By Iain Bartlett