RESUMEN
Objectives@#This study aimed to investigate the in vitro osteoinductivity of the combination of bone morphogenetic protein-2 (BMP-2) and nanohydroxyapatite (nHAp) and the in vivo effects of implants coated with nHAp/BMP-2. @*Materials and Methods@#To evaluate the in vitro efficacy of nHAp/BMP-2 on bone formation, bone marrow-derived mesenchymal stem cells (BMMSCs) were seeded onto titanium disks coated with collagen (Col), ColHAp, or ColHAp/BMP-2. Protein levels were determined by a biochemical assay and reverse transcriptase-polymerase chain reaction. Stem cell differentiation was analyzed by flow cytometry. For in vivo studies with mice,Col, ColHAp, and ColHAp/BMP-2 were injected in subcutaneous pockets. Titanium implants or implants coated with ColHAp/BMP-2 were placed bilaterally on rabbit tibias and evaluated for 4 weeks. @*Results@#In the in vitro study, BM-MSCs on ColHAp/BMP-2 showed reduced levels of CD73, CD90, and CD105 and increased levels of glycos-aminoglycan, osteopontin, and alkaline phosphatase activity. After 4 weeks, the ColHAp/BMP-2 implant showed greater bone formation than the control (P=0.07), while no differences were observed in bone implant contact and removal torque. @*Conclusion@#These results suggest that a combination of BMP-2 and an nHAp carrier would activate osseointegration on dental implant surfaces.
RESUMEN
PURPOSE: This study assessed marginal bone remodeling and soft tissue esthetics after the loading of single bone-level implants in the anterior maxilla. METHODS: An open, single-arm observational clinical trial with 3 years of follow-up was performed, including 22 implants. The patients presented with a single tooth gap in the anterior maxilla (tooth positions 14–24), with natural or restored adjacent teeth. An implant was placed at least 8 weeks post-extraction and healed submerged for 6 weeks. After the second-stage operation, a fixed provisional prosthesis was provided. The final restoration was placed 6 months after the provisional restoration. The time of the provisional crown connection was considered to be the baseline in this study. Esthetic parameters and the marginal bone level were assessed at 6, 12, 24, and 36 months. RESULTS: All implants were well integrated in the bone. A statistically significant increase was found in the mean implant stability quotient between the time of the provisional prosthesis and the time of the final prosthesis. Most implants (95.5%) revealed marginal bone resorption (<0.5 mm), and just 1 implant (4.5%) showed a change of 2.12 mm from baseline to 36 months (mean 0.07±0.48 mm), while the crestal bone level decreased significantly, from 2.34±0.93 mm at baseline to 1.70±1.10 mm at 36 months. The facial gingival margin and papilla were stable and the esthetic scores indicated high patient and dentist satisfaction. CONCLUSIONS: Platform-switching bone-level implants placed in maxillary single-tooth gaps resulted in successful osseointegration with minimal marginal bone resorption. The peri-implant soft tissue was also esthetically satisfying and stable.