Background: The aim of this study is to investigate the potential use of periosteum‐derived cells (PCs) for tissue engineering in peri‐implant defects.Methods: Bone marrow cells (BMCs) and PCs were harvested from seven adult beagle dogs, cultured in vitro, and phenotypically characterized with regard to their osteogenic properties. The animals were then subjected to teeth extraction, and 3 months later, two implant sites were drilled, bone dehiscences created, and dental implants placed. Dehiscences were randomly assigned to one of two groups: PCs (PCs + carrier) and BMCs (BMCs + carrier). After 3 months, the animals were sacrificed and the implants with adjacent hard tissues were processed for undecalcified sections. Bone‐to‐implant contact, bone fill within the limits of implant threads, and new bone area in a zone lateral to the implant were histometrically obtained.Results: In vitro, phenotypic characterization demonstrated that both cell populations presented osteogenic potential, as identified by the mineral nodule formation and the expression of bone markers. Histometrically, an intergroup analysis showed that both cell‐treated defects had similar bone fill within the limits of implant threads and bone‐to‐implant contact (P >0.05), and although a trend toward higher new bone area values was found for the PC group, there was no significant difference between the experimental groups (P >0.05).Conclusions: Periosteal and bone marrow cells presented a similar potential for bone reconstruction. As such, periosteum may be considered as an alternative source of osteogenic cells in implant dentistry.

Background: It is known that periodontal ligament (PDL) harbors a heterogeneous progenitor cell population at different stages of lineage commitment. However, characterization of PDL stem cells committed to osteoblast/cementoblast (O/C) differentiation remains to be elucidated. The present study is carried out to isolate single cell–derived, cluster of differentiation (CD)105–positive PDL clones and to characterize the clones that present high potential to differentiate toward O/C phenotype in vitro.Methods: Isolation of single cell–derived colonies (clones) from a CD105‐enriched PDL progenitor cell population was performed by the ring‐cloning technique. Cell clones were evaluated for their O/C differentiation potential, metabolic activity, and expression of STRO‐1 protein. Additionally, the clones that showed potential to O/C differentiation were characterized by quantitative reverse‐transcription polymerase chain reaction (qRT‐PCR) for expression of runt‐related transcriptor factor 2 (RUNX2), alkaline phosphatase, CD105, and CD166 during osteogenic induction.Results: Six PDL‐CD105⁺ clones were obtained, three being highly O/C clones (C‐O) and three others that did not have the ability to produce mineralized matrix in vitro (C‐F). The C‐O group showed lower metabolic activity compared with the C‐F group, and both cell groups were positively immunostained for STRO‐1. qRT‐PCR analysis demonstrated an increased expression of transcripts for RUNX2 and CD166 during the maturation of C‐O cells toward O/C phenotype.Conclusions: These results provide evidence that PDL‐CD105⁺ purified progenitor cells comprise a heterogeneous cell population that presents a cell subset with high O/C potential and, further, that surface antigen CD166 is modulated during the O/C maturation of this cell subset.