Bone formation following implantation of titanium sponge rods into humeral osteotomies in dogs: a histological and histometrical study.
BACKGROUND
Titanium (Ti) is widely proven to enhance bone contact and growth on its surface. It is expected that bone defects could benefit from Ti to promote healing and to increase strength of the implanted area.


OBJECTIVE
The present study aimed at comparing the potential of porous Ti sponge rods with synthetic hydroxyapatite (HA) for the healing of bone defects in a canine model.


METHODS
Six mongrel dogs were submitted to three trephined osteotomies of 6.0 x 4.0 mm in one humerus and after 2 months another three osteotomies were performed in the contralateral humerus. A total of 36 defects were randomly filled either with Ti foam, particulate HA, or coagulum (control). The six animals were killed 4 months after the first surgery for histological and histometrical analysis.


RESULTS
The Ti-foam surface was frequently found in intimate contact with new bone especially at the defect walls. Control sites showed higher amounts of newly formed bone at 2 months - Ti (p = 0.000) and HA (p = 0.009) - and 4 months when compared with Ti (p = 0.001). Differently from HA, the Ti foam was densely distributed across the defect area which rendered less space for bone growth in the latter's sites. The use of Ti foams or HA resulted in similar amounts of bone formation in both time intervals. Nevertheless, the presence of a Ti-foam rod preserved defect's marginal bone height as compared with control groups. Also, the Ti-foam group showed a more mature bone pattern at 4 months than HA sites.


CONCLUSIONS
The Ti foam exhibited good biocompatibility, and its application resulted in improved maintenance of bone height compared with control sites. The Ti foam in a rod design exhibited bone ingrowth properties suitable for further exploration in other experimental situations.
Faria
Paulo Esteves Pinto
PE
Department of Oral & Maxillofacial Surgery, Faculty of Dentistry of Araçatuba, University of São Paulo, Campus USP 14040-904 Ribeirão Preto, São Paulo, Brazil.
Carvalho
Alexandre Leite
AL
Felipucci
Daniela Nair Borges
DN
Wen
Cui'e
C
Sennerby
Lars
L
Salata
Luiz Antonio
LA
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001847:Bone Diseases / Q000473:pathology / Q000601:surgery; D001853:Bone Marrow / Q000473:pathology; D018786:Bone Substitutes / Q000627:therapeutic use*; D004396:Coloring Agents; D004195:Disease Models, Animal; D004285:Dogs; D017886:Durapatite / Q000627:therapeutic use*; D006811:Humerus / Q000473:pathology / Q000601:surgery*; D008297:Male; D010012:Osteogenesis / Q000502:physiology*; D010027:Osteotomy / Q000379:methods*; D011754:Pyronine; D011897:Random Allocation; D013997:Time Factors; D054457:Tissue Scaffolds; D014025:Titanium / Q000737:chemistry*; D014048:Tolonium Chloride
D001672:Biocompatible Materials; D018786:Bone Substitutes; D004396:Coloring Agents; D014048:Tolonium Chloride; D017886:Durapatite; D014025:Titanium; D011754:Pyronine