Evaluation of implant osseointegration with different regeneration techniques in the treatment of bone defects around implants: an experimental study in a rabbit model.
OBJECTIVE
The aim of this study was to evaluate the osseointegration of implants placed in areas with artificially created bone defects, using three bone regeneration techniques.


METHODS
The experimental model was the rabbit femur (16), where bone defects were created and implants were placed. The peri-implant bone defects were filled with a deproteinized bovine bone mineral, NuOss™ (N), NuOss™ combined with plasma rich in growth factors (PRGF) (N+PRGF), NuOss™ covered by an RCM(6) membrane (N+M), or remained unfilled (control group [C]). After 4 and 8 weeks, the animals were euthanized and bone tissue blocks with the implants and the surrounding bone tissue were removed and processed according to a histological protocol for hard tissues on non-decalcified ground sections. The samples were studied by light and electron scanning microscopy, histometric analysis was performed to assess the percentage of bone in direct contact with the implant surface and a statistical analysis of the results was performed.


RESULTS
In the samples analyzed 4 weeks after implantation, the percentage of bone tissue in direct contact with the implant surface for the four groups were 57.66±24.39% (N), 58.62±20.37% (N+PRGF), 70.82±20.34 % (N+M) and 33.07±5.49% (C). In the samples with 8 weeks of implantation time, the percentage of bone in direct contact was 63.35±27.69% (N), 58.42±24.77% (N+PRGF), 78.02±15.13% (N+M) and 40.28±27.32% (C). In terms of the percentage of bone contact, groups N and N+M presented statistically significant differences from group C in the 4-week trial test (P<0.05; ANOVA). For the 8-week results, only group N+M showed statistically significant differences when compared with group C (P<0.05; ANOVA).


CONCLUSIONS
In conclusion, the NuOss™ granules/RCM(6) membrane combination presented a percentage of bone contact with the implant surface statistically greater than in the other groups.
Guerra
Isabel
I
imlguerra@gmail.com
Morais Branco
Fernando
F
Vasconcelos
Mário
M
Afonso
Américo
A
Figueiral
Helena
H
Zita
Raquel
R
D000818:Animals; D001847:Bone Diseases / Q000473:pathology / Q000601:surgery*; D001861:Bone Regeneration / Q000502:physiology*; D018786:Bone Substitutes / Q000627:therapeutic use; D002417:Cattle; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D004195:Disease Models, Animal; D005269:Femur / Q000473:pathology / Q000601:surgery*; D048091:Guided Tissue Regeneration / Q000379:methods*; D006253:Haversian System / Q000473:pathology; D036341:Intercellular Signaling Peptides and Proteins / Q000627:therapeutic use; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000627:therapeutic use; D016348:Osseointegration / Q000502:physiology*; D010006:Osteoblasts / Q000473:pathology; D010011:Osteocytes / Q000473:pathology; D053657:Platelet-Rich Plasma; D011817:Rabbits; D011897:Random Allocation; D013997:Time Factors; D014025:Titanium / Q000737:chemistry
D018786:Bone Substitutes; D015921:Dental Implants; D003764:Dental Materials; D036341:Intercellular Signaling Peptides and Proteins; D008567:Membranes, Artificial; D008903:Minerals; D014025:Titanium