Histological evaluation, in rabbit tibiae, of osseointegration of mini-implants in sites prepared with Er:YAG laser versus sites prepared with traditional burs.
OBJECTIVE
The aim of this study was to evaluate the different bone reactions in rabbit tibiae after the insertion of mini-implants by using two different techniques of site preparation: the superpulsed Er:YAG laser (VPS system) versus the traditional technique with burs.


METHODS
One mm wide and 2 mm long implant sites were made in the tibiae of 12 rabbits (8 for each tibia): the authors used an Er:YAG laser with a sapphire tip on a contra-angle hand piece with a 1.0 mm diameter in a VPS mode (with 200 mJ and 30 Hz) to make 4 bone sites and a calibrated traditional bur to drill the other 4 sites in each tibia. The authors inserted a threaded mini-implant, with a sandblasted and acid-etched surface, in the 2 laser implant sites and in the 2 drilled sites of each tibia. The other sites were used as controls. At 0, 7, 15, 30, 45, and 60 days from the surgery, 2 animals each were euthanized, and the retrieved specimens were evaluated.


RESULTS
No implant was lost, and the osseointegration was comparable in all implant sites. Histologically, in the 7- and 15-day postoperative specimens, the laser sites showed some amorphous tissue caused by the carbonization of bone during the laser procedure. The sites without implants showed good regeneration of the bone: it was faster in the drill defects because in the laser ones there was some carbonized amorphous tissue. After 30 days postoperatively, the regeneration was the same in all sites.


CONCLUSIONS
In comparison with the traditional drilling procedures, Er:YAG laser can be considered efficient in surgery of the bone without inducing irreversible damages, even if it is possible to observe the presence of some carbonized amorphous tissue in the early part of the healing process. This tissue is progressively resorbed in a way similar to a bone graft and doesn't impede the bone formation and osseointegration processes. Further clinical and histological studies are necessary to better define this amorphous tissue and an efficient and safe operative protocol in the surgery of bone with an Er:YAG laser.
Salina
Sergio
S
Department of Periodontology and Implantology, University of Milan, Dental Clinic (ICP), Milan, Italy.
Maiorana
Carlo
C
Iezzi
Giovanna
G
Colombo
Alessandro
A
Fontana
Filippo
F
Piattelli
Adriano
A
D000818:Animals; D001672:Biocompatible Materials; D053685:Laser Therapy / Q000295:instrumentation*; D016348:Osseointegration / Q000502:physiology*; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000295:instrumentation*; D011817:Rabbits; D013977:Tibia / Q000166:cytology*; D014025:Titanium
D001672:Biocompatible Materials; D014025:Titanium