Five-year results of a prospective, randomized, controlled study evaluating treatment of intra-bony defects with a natural bone mineral and GTR.

Background: Treatment with a natural bone mineral (NBM) and a guided tissue regeneration (GTR) has been shown to promote periodontal regeneration. However, until now there are only very limited data on the long-term clinical results following this regenerative technique.
Aim: To present the 5-year results of a prospective, randomized, controlled clinical study evaluating the treatment of deep intra-bony defects either with open flap debridement (OFD) and a combination of an NBM and GTR (test) or OFD alone (control).
Methods: Nineteen patients diagnosed with advanced chronic periodontitis, and each of whom displayed one intra-bony defect, received randomly the test or the control treatment. Results were evaluated at baseline, at 1 and at 5 years following therapy.
Results: No statistically significant differences in any of the investigated parameters were observed at baseline between the two groups. At 1 year after therapy, the test group showed a reduction in mean probing depth (PD) from 9.1+/-1.1 to 3.7+/-0.8 mm (p<0.001) and a change in mean clinical attachment level (CAL) from 10.4+/-1.3 to 6.4+/-1.2 mm (p<0.001). At 5 years, mean PD and CAL measured 4.3+/-0.8 and 6.7+/-1.6 mm, respectively. At 5 years, both PD and CAL were statistically significantly improved compared with baseline (p<0.001) without statistically significant differences between the 1- and 5-year results. In the control group, mean PD was reduced from 8.9+/-1.3 to 4.9+/-1.2 mm (p<0.001) and mean CAL changed from 10.6+/-1.4 to 8.8+/-1.5 mm (p<0.01). At 5 years, mean PD and CAL measured 5.6+/-1.1 and 9.1+/-1.3 mm, respectively, and were still statistically significantly improved compared with baseline (p<0.01). No statistically significant differences were found between the 1- and 5-year results. The test treatment, at both 1 and 5 years, yielded statistically significantly higher CAL gains than the control one (p<0.01). Compared with baseline, at 5 years a CAL gain of > or =3 mm was found in nine defects (90%) of the test group but in none of the defects treated with OFD alone.
Conclusions: It was concluded that (i) treatment of intra-bony defects with OFD+NBM+GTR may result in significantly higher CAL gains than treatment with OFD, and (ii) the clinical results obtained after both treatments can be maintained over a period of 5 years.