Sequential Fluorescent Labeling Observation of Maxillary Sinus Augmentation by a Tissue-engineered Bone Complex in Canine Model

Aim To evaluate the effects of maxillary sinus floor elevation by a tissue-engineered bone complex of β-tricalcium phosphate （β-TCP） and autologous osteoblasts in dogs. Methodology Autologous osteoblasts from adult Beagle dogs were cultured in vitro. They were further combined with β-TCP to construct the tissue-engineered bone complex. 12 cases of maxillary sinus floor elevation surgery were made bilaterally in 6 animals and randomly repaired with the following 3 groups of materials： Group A （osteoblasts/D-TCP）; Group B （β-TCP）; Group C （autogenous bone） （n=4 per group）. A polychrome sequential fluorescent labeling was performed post-operatively and the animals were sacrificed 24 weeks after operation for histological observation.Results Our results showed that autologous osteoblasts were successfully expanded and the osteoblastic phenol- types were confirmed by ALP and Alizarin red staining. The cells could attach and proliferate well on the surface of the ~3-TCP scaffold. The fluorescent and histological observation showed that the tissue-engineered bone complex had an earlier mineralization and more bone formation inside the scaffold than β-TCP along or even autologous bone. It had also maximally maintained the elevated sinus height than both control groups. Conclusion Porous 13-TCP has served as a good scaffold for autologous osteoblasts seeding. The tissue-engineered bone complex with β-TCP and autologous osteoblasts might be a better alternative to autologous bone for the clinical edentulous maxillary sinus augmentation.

Minimally invasive maxillary sinus augmentation with simultaneous implantation on an elderly patient:A case report

BACKGROUND In this case study,a minimally invasive transalveolar approach using platelet-rich fibrin and bone substitute with simultaneous implantation was carried out in an elderly patient.We analyzed the cone-beam computed tomography(CBCT)findings to evaluate bone regeneration.CASE SUMMARY A 65-year-old female with no contraindications for dental implants and loss of maxillary bilateral molars is described.Examination by CBCT showed the available vertical bone height in the bilateral posterior maxilla was 0.5-6.8 mm in the left and 2.8-6.5 mm in the right.The patient underwent a transalveolar approach using platelet-rich fibrin and bone substitute with simulataneous placement of an implant 10 mm in length.Six months post-surgery,the implant showed excellent osseointegration with the bone graft.Thereafter,full-ceramic crowns were fitted.Follow-up at 2 years demonstrated satisfactory prognosis.CONCLUSION Platelet-rich fibrin and bone substitute can be used to augment the maxillary sinus with a vertical bone height less than 4 mm.

Ultrastructure and Analytical Features of the Sinus Floor Augmentation with Osteograph^(█) and PepGen P-15^(█)

The aim of the present study was to investigate an inorganic bovine-derived hydroxyapatite bone substitute (Osteograph?) mixed with the same biomaterial coated with a synthetic peptide (P-15) analogue of collagen (PepGen P-15?). This blend of bone replacement materials was used for sinus floor augmentation. Assessments were carried out by using histology methods, transmission electron microscopy (TEM) and microanalysis (EDX). Ultrastructural and analytical features of the interfaces between the graft material and the peri-biomaterial tissues were evaluated six months after implantation. Our findings clearly show that newly-formed crystallites first develop at the surface of implanted crystals. Histological investigations revealed new bone tissue linking biomaterial particles together. TEM assessments pointed out that lamellar bone was generally separated from the graft material by a layer of woven bone measuring between 1 and 1.5 μm in thickness. Although calcified bone tissue was observed in direct contact with bone filling particles, the presence of mineralized granular material around implanted particles was also noticed. No characteristic periodic striation of mineralized collagen was evident within that mineralized structure. Chemical analyses (TEM-EDX) realized at different locations of newly formed mineralized granular substance along the interface revealed average Ca/P ratios ranging between 1.02 and 1.63. The different, concomitantly occurring, aforementioned structural features of the interfaces strongly suggested that the host responses to the used biomaterial blend resulted from dynamic osseointegration phenomena related to various interfacial mechanisms. Nevertheless, the biological response to the bone graft material appeared clinically and histologically satisfactory.

A Simple Method of Managing the Alveolar Antral Artery during Sinus Lift Surgery

The alveolar antral artery resides lateral to the maxillary sinus and can lead to complications in sinus lift surgery. Traditional approaches that decrease intraoperative bleeding into the surgical field include vessel preservation using multiple bony windows or neutralizing the vessel at the surgical site. Unfortunately, these methods are technique sensitive, time intensive, and may lead to hemosinus and graft loss. The variable distance from the crest of the alveolar ridge and vessel diameter further complicates pre-operative planning. This paper discusses the anatomical features of the alveolar antral artery, techniques for clinical assessment, and current management strategies. We then describe a novel protocol to manage the alveolar antral artery in sinus lift procedures via tamponade of the vessel at a proximal site. This method is faster than those described in the literature, does not require any additional equipment or expertise, and aims to improve long-term graft predictability by decreasing the risk of sinus membrane perforation. The alveolar antral artery is an under-reported source of surgical complications and warrants further research.

Improved guided bone regeneration by combined application of unmodified, fresh autologous adipose derived regenerative cells and plasma rich in growth factors:A first-in-human case report and literature review

BACKGROUND Novel strategies are needed for improving guided bone regeneration(GBR) in oral surgery prior to implant placement, particularly in maxillary sinus augmentation(GBR-MSA) and in lateral alveolar ridge augmentation(LRA). This study tested the hypothesis that the combination of freshly isolated, unmodified autologous adipose-derived regenerative cells(UA-ADRCs), fraction 2 of plasma rich in growth factors(PRGF-2) and an osteoinductive scaffold(OIS)(UAADRC/PRGF-2/OIS) is superior to the combination of PRGF-2 and the same OIS alone(PRGF-2/OIS) in GBR-MSA/LRA.CASE SUMMARY A 79-year-old patient was treated with a bilateral external sinus lift procedure as well as a bilateral lateral alveolar ridge augmentation. GBR-MSA/LRA was performed with UA-ADRC/PRGF-2/OIS on the right side, and with PRGF-2/OIS on the left side. Biopsies were collected at 6 wk and 34 wk after GBRMSA/LRA. At the latter time point implants were placed. Radiographs(32 mo follow-up time) demonstrated excellent bone healing. No radiological or histological signs of inflammation were observed. Detailed histologic,histomorphometric, and immunohistochemical analysis of the biopsies evidenced that UA-ADRC/PRGF-2/OIS resulted in better and faster bone regeneration than PRGF-2/OIS.CONCLUSION GBR-MSA with UA-ADRCs, PRGF-2, and an OIS shows effectiveness without adverse effects.