Sequential healing events of osseointegration at UnicCa(®) and SLActive(®) implant surfaces: an experimental study in the dog

AimTo study the sequential events in osseointegration at implants with highly hydrophilic surfaces.Material and methodsAll premolars and the first molars were bilaterally extracted in 12 Beagle dogs. After 3months, full-thickness flaps were elevated and two different implants systems with various surfaces were randomly installed in the edentulous premolar region in one side of the mandible. One surface was acid etched and further modified with calcium ions (UnicCa((R))), while the other was sandblasted with large grits and acid etched (SLActive((R))). The flaps were sutured to allow a fully submerged healing. The surgery on the other side of the mandible and the sacrifices were planned in such a way to obtain biopsies representing the healing after 1, 2, 4, and 8weeks (n=6 per period).ResultsAfter one week of healing, new bone apposition was found at both surfaces with percentages of 6.93.3% and 6.1 +/- 4.6% at UnicCa((R)) and SLActive((R)), respectively. After 2weeks, the percentages had increased to 29.1 +/- 11.9% and 21.6 +/- 14.3%, respectively. After 4 and 8weeks of healing, mean values of 46.3 +/- 7.3% and 58.7 +/- 15.1% at UnicCa((R)) and 51.2 +/- 16.1% and 68.9 +/- 15.4% at SLActive((R)) surfaces were found, respectively. None of the differences in percentages were statistically significant. Concomitantly, the old bone was resorbed at both surfaces from about 21-22% after 1week to about 4-6% after 8weeks of healing.ConclusionsThe osseointegration process onto moderately rough titanium implant surfaces of high hydrophilicity was very similar for two implant systems that were both nanotechnologically modified.