In vitro osteogenesis induced by cells derived from sites submitted to sinus grafting with anorganic bovine bone.
OBJECTIVE
This study evaluated key parameters of the in vitro osteogenesis induced by osteoblastic cells obtained from sites submitted to sinus grafting with anorganic bovine bone (ABB) in comparison with cells derived from bone sites of the same patients.


METHODS
In three patients, the augmentation of maxillary sinus was carried out using ABB (Bio-Oss). After at least 6 months, during the surgical intervention for titanium implants placement, biopsies were taken from these areas using trephine burs (grafted group). Bone fragments, of the same patients, from sites that had not received graft were also obtained with trephine burs and used as a control group. Osteoblastic cells were obtained from grafted and control groups by enzymatic digestion and cultured under standard osteogenic condition until subconfluence. First passaged cells were cultured in 24-well culture plates. Cell adhesion was evaluated at 24 h. For proliferation and viability assay, cells were cultured for 1, 3, 7, and 10 days. Total protein content and alkaline phosphatase (ALP) activity were measured at 3, 7, 10, 14, 17, and 21 days. Cultures were stained with Alizarin red S at 21 days, for detection of mineralized matrix. Data were compared by Student's t-test.


RESULTS
Cell adhesion and viability were not affected by cell source (P>0.05). Total protein content was greater (P<0.05) for grafted group. Cell proliferation, ALP activity, and bone-like nodule formation were all greater (P<0.05) for the control group.


CONCLUSIONS
Taken together, these results indicate that the in vivo long-term contact of cells with ABB downregulates the expression of osteoblast phenotype and consequently the in vitro osteogenesis.
Beloti
Marcio Mateus
MM
School of Dentistry of Ribeirao Preto, University of Sao Paulo, Sao Paulo, Brazil.
Martins
Walter
W
Xavier
Samuel Porfirio
SP
Rosa
Adalberto Luiz
AL
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D018786:Bone Substitutes / Q000494:pharmacology*; D002417:Cattle; D002448:Cell Adhesion; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D015536:Down-Regulation; D006801:Humans; D008443:Maxillary Sinus / Q000601:surgery*; D008903:Minerals / Q000494:pharmacology*; D013516:Oral Surgical Procedures, Preprosthetic; D010006:Osteoblasts / Q000187:drug effects* / Q000502:physiology; D010012:Osteogenesis; D011506:Proteins / Q000032:analysis
C077540:Bio-Oss; D018786:Bone Substitutes; D008903:Minerals; D011506:Proteins; D000469:Alkaline Phosphatase