Assessment of peri-implant tissue dimensions following surgical therapy of advanced ligature-induced peri-implantitis defects

Background To evaluate peri-implant tissue dimensions following implantoplasty and/or regenerative therapy of advanced ligature-induced peri-implantitis in dogs. Material and methods At all defect sites (n = 6 dogs, n = 48 implants), the intrabony component was filled with a particulate bovine-derived natural bone mineral (NBM). The supracrestal component was treated by either the application of an equine bone block (EB) or implantoplasty. In a split-mouth design, NBM and EB were soak-loaded with rhBMP-2 or sterile saline. All sites were covered using a native collagen membrane and left to heal in a submerged position for 12 weeks. The horizontal mucosal thickness (hMT) and bone thickness (hBT) were measured at four reference points: (v0) at the level of implant shoulder (IS), (v1) 50% of the distance IS-bone crest (BC), (v2) at the BC, and (v3) at the most coronal extension of the bone-to-implant contact. Results The general tendency indicated a gradual increase in hMT from the IS (v0) toward BC (v2), which was more pronounced at implant sites treated with the regenerative approach. The hBT values increased from v2 to v3, with the highest values at the v3 region measured for implant sites treated with adjunctive rhBMP-2. For sites treated with implantoplasty, the linear regression model demonstrated an inverse correlation between hMT and hBT, whereas a positive correlation was observed at those sites treated with the regenerative approach. Conclusion Horizontal soft and hard tissue dimensions were similar among different treatment groups.

The shape-effect of calcium phosphate nanoparticle based films on their osteogenic properties

Calcium phosphates (CaPs) in the form of hydroxyapatite (HA) have been extensively studied in the context of bone regeneration due to their chemical similarity to natural bone mineral. While HA...

Fabrication and Application of a 3D-Printed Poly-ε-Caprolactone Cage Scaffold for Bone Tissue Engineering

Poly-ε-caprolactone (PCL) is a promising synthetic material in bone tissue engineering (BTE). Particularly, the introduction of rapid prototyping (RP) represents the possibility of manufacturing PCL scaffolds with customized appearances and structures. Bio-Oss is a natural bone mineral matrix with significant osteogenic effects; however, it has limitations in being constructed and maintained into specific shapes and sites. In this study, we used RP and fabricated a hollow-structured cage-shaped PCL scaffold loaded with Bio-Oss to form a hybrid scaffold for BTE. Moreover, we adopted NaOH surface treatment to improve PCL hydrophilicity and enhance cell adhesion. The results showed that the NaOH-treated hybrid scaffold could enhance the osteogenesis of human bone marrow-derived mesenchymal stem cells (hBMMSCs) both in vitro and in vivo. Altogether, we reveal a novel hybrid scaffold that not only possesses osteoinductive function to promote bone formation but can also be fabricated into specific forms. This scaffold design may have great application potential in bone tissue engineering.

Treatment of Peri-implantitis—Electrolytic Cleaning Versus Mechanical and Electrolytic Cleaning—A Randomized Controlled Clinical Trial—Six-Month Results

Objectives: The present randomized clinical trial assesses the six-month outcomes following surgical regenerative therapy of periimplantitis lesions using either an electrolytic method (EC) to remove biofilms or a combination of powder spray and electrolytic method (PEC). Materials and Methods: 24 patients with 24 implants suffering from peri-implantitis with any type of bone defect were randomly treated by EC or PEC. Bone defects were augmented with a mixture of natural bone mineral and autogenous bone and left for submerged healing. The distance from implant shoulder to bone was assessed at six defined points at baseline (T0) and after six months at uncovering surgery (T1) by periodontal probe and standardized x-rays. Results: One implant had to be removed at T1 because of reinfection and other obstacles. None of the other implants showed signs of inflammation. Bone gain was 2.71 ± 1.70 mm for EC and 2.81 ± 2.15 mm for PEC. No statistically significant difference between EC and PEC was detected. Significant clinical bone fill was observed for all 24 implants. Complete regeneration of bone was achieved in 12 implants. Defect morphology impacted the amount of regeneration. Conclusion: EC needs no further mechanical cleaning by powder spray. Complete re-osseointegration in peri-implantitis cases is possible.

Implant-Supported Rehabilitation Using GBR Combined with Bone Graft on a Reconstructed Maxilla with the Fibula Free Flap

Alveolar ridge augmentation procedures allow restoring jaw defects due to teeth extractions, periodontal diseases, trauma, or outcomes from a previous surgery. This case report describes a patient suffering from Fibrous Dysplasia of the right upper maxilla surgically reconstructed by fibula free flap. In 2003, four dental implants were placed in the 1.2, 1.3, 1.5, and 1.6 areas. Twelve years later, the onset of peri-implantitis led to the failure of osseointegration with consequent thinning of the fibula flap. To avoid the risk of fracture and to restore the bone volumes necessary for a new implant-prosthetic rehabilitation, we used heterologous biomaterials in combination with a non-reabsorbable membrane, according to the Guided Bone Regeneration (GBR) technique. GBR was performed using the Equimatrix® natural bone mineral matrix, Cytoplast™ Ti-150, a non-reabsorbable titanium-reinforced membrane, and four fastening screws to pin the membrane. After six months, the membrane was removed and two Zimmer® implants 3.7×13 mm were placed in the 1.1 and 1.2 areas. A fixed implant-supported prosthesis with a custom-milled titanium bar screwed to the implants was made. Computed tomography (CT) six months after GBR showed a good bone regeneration of 1.5 cm mesiodistal (MD), 1.8 cm buccopalatal (BP), and 2.8 cm in height. The main difficulty of this clinical case concerns the low predictability of success of GBR on a maxillary reconstructed area with a free fibula flap: there is no previous evidence in the literature. Clinical and radiographic exams nowadays show that there is no macroscopic bone reabsorption; however, further research is needed to obtain more information.

Mechanical Properties of Hydroxyapatite Reinforced 45S5

Hydroxyapatite (HA) has similar constituent with natural bone mineral and is able to evoke apatite formation on the bone interface. Similarly, bioactive glass (BG) such as 45S5 has the ability to induce bone formation when exposed to physiological environment. However, both materials have drawbacks in mechanical properties such as brittleness and low compressive strength. Hence, HA-BG composite has potential for enhance properties. The current work aims to assess the effects of BG addition in HA system focusing on mechanical properties.

Characterization of Gelatin Composite with Low Content Hydroxyapatite and the Influence on Mesenchymal Stem Cell Culture

In tussue engineering, hydrogel-based scaffold is one of the most common method for bone tissue engineering. Gelatin is a common material for scaffold, whereas hydroxyapatite (HA) has a similar composition and structure to natural bone mineral. HA can also increase cell adhesion ability of the scaffold. This research focuses on the fabrication of hydrogel scaffolds using gelatin composite with nanocrystalline hydroxyapatite (nHA). Then the mechanical and physical caharacteristics of the scaffold is investigetad. Low contents nHA is introduced into gelatin in order to modulate mesenchymal stem cell (MSC) behavior. There are three types of scaffolds which contain various HA content. The gelatin is crosslinked with glutaraldehyde before freeze-drying. The Young’s modulus of the surface is investigated using Atomic force microscopy (AFM). The pore size is investigated using scanning electron microscope (SEM). Human MSCs are culture on the scaffold for 3 weeks. The result shows the sucesse in cell cultivation. However, the human MSCs cultured on the fabricated hydrogels do not show any lineage-specific differentiation.