Journal of "Regeneration, Reconstruction & Restoration" (Triple R)

Introduction: Reconstruction of large bone defects at the load bearing sites like spinal cord are still associating with major challenges. Although, currently two commercially available implants like porous tantalum and polyether-ether-ketone (PEEK) cage are employed for spinal fusion surgery, however, both PEEK and tantalum are suffered a key property of bioinert surface. By coating the surface of implants with collagen type 1, it is expected surface wettability and bioactivity of implants be increased and consequently effects on cells behavior. The aim of this study was to compare the attachment, proliferation and osteogenic differentiation capability of human dental pulp derived stem cells (DPSCs) cultured on either collagen coated polyether ether ketone (PEEK) and tantalum and bare ones.

Materials and Methods: Porous tantalum (Zimmer Company, USA) and PEEK (Abbott Spine, France) fragmented samples were treated by oxygen plasma irradiation following coated with collagen type 1 and seeded with dental pulp derived stem cells (DPSCs). Cells adhesion, proliferation, and osteogenic differentiation of DPSCs were evaluated on these both coated and non-coated scaffolds for up to two weeks by scanning electron microscopy (SEM) imaging, Alamar blue assay and alkaline phosphate (ALP) activity measuring respectively.

Results: Alamar blue assay was performed and results over 5 and 7 days of culture showed that cell viability for collagen coated porous tantalum group at those days was higher than other ones. Likewise, ALP activity of cells which were seeded on scaffolds measured and interestingly, collagen coated tantalum group had highest amount over 7 and 14 days of culture. The adherence of DPSCs on the scaffolds was recorded after 3 days of culture by scanning electron microscopy (SEM) imaging. According to the SEM images, cells colonies and cells sheets were formed at the collagen coated porous tantalum and collagen coated PEEK surfaces respectively, whereas no cell attachments was seen at the surface of either bare tantalum or bare PEEK.

Conclusion: Our results, therefore, show that the collagen coated porous tantalum in comparison to coated PEEK or bare ones, possess better cells attachments and biocompatibility and could be considered for using as cell seeded scaffold for orthopedic in vivo studies.

Introduction: Photobiomodulation (PBM) has been considered a popular technique for reducing the post-operative complications after periodontal surgeries. The aim of this case series study was to evaluate the PBM effect on accelerating wound healing after crown lengthening procedure.

Materials and Methods: Four patients were referred to a private office for crown lengthening surgery. After completion of medical history and oral examination, the surgery for patients were done. Then, PBM was done by diode laser at 980 nm, in continuous mode with output power of 0.3 w for 20 sec.

Results: On follow up session after 2 weeks, satisfactory results of PBM were detected in all patients.

Conclusion: The application of 980 nm diode laser for PBM after oral soft tissue surgeries can be beneficial due to accelerating wound healing.

Introduction: Bone drilling and expansion techniques have been used for implant site preparation. However, histological studies comparing these two techniques are limited. This study aimed to histologically assess the bone quality in the implant sites prepared by the bone drilling and expansion techniques in a sheep model.

Materials and Methods: This experimental animal study was conducted on three sheep and four sites were chosen in their mandibles. Implant holes were created by bone drilling and expansion techniques in an alternate fashion. The first sheep underwent vital perfusion immediately after surgery and its mandible was fixed. The second and the third sheep were subjected to vital perfusion 19 and 26 days after surgery, respectively. The collected samples were stained with hematoxylin and eosin and the percentage of osteogenesis, the amount of ossification and sequester area, were measured by computer assisted histomorphometric analysis system. The amount of inflammation was estimated for each sample, considering the frequency of inflammatory cells infiltration, in terms of degree of inflammation as zero, less than 10% and more than 10%, under x400 magnification.

Results: No significant difference was noted between the drilling and expansion techniques for implant site preparation in terms of degree of inflammation or rate of osteogenesis. The amount of sequesters was different between the two groups in the first days after surgery but no significant difference was noted in this regard between the two groups after 3 weeks.

Conclusion: according to the histological evaluation, the method of implant sites preparation does not effect of quality of bone regeneration.

Introduction: Since the determination of skeletal maturation by surveying concavity on lower surface of cervical vertebrae and evaluating shape of vertebrae is a subjective and quantitative study, this systematic review was performed to evaluate new quantitative and objective methods by using cervical vertebrae for determining skeletal maturation.

Material and Methods: Related keywords were searched in Pubmed and Cochran database in order to find studies that were published in English from January 2000 to January 2019 and evaluated skeletal maturation based on cervical vertebrae by modern methods. Also, the references of the included studies were search for other related studies.

Results: From overall 1371 titles, 27 were selected by initial screening. Evaluation of the full texts resulted in inclusion of 13 articles. Among articles included in this review, three studies used CBCT images and another studies used lateral cephalogram. One study performed evaluation cervical vertebrae in the axial view of CBCT images while another evaluation was on sagittal view. Most of the studies used a regression model in order to determine bone age of vertebrae and then compared it with skeletal age obtained from hand wrist radiography.

Conclusion: As the methods and measurements were different in the included studies it was not possible to reach a decisive conclusion regarding method for determining skeletal age based on cervical vertebrae. It is suggested to use a combination of maturation signs along with development stages of cervical vertebrae in order to determine skeletal maturation until a quantitative and valid method is presented.