Bio-active cements-Mineral Trioxide Aggregate based calcium silicate materials: a narrative review.

Recent advances in the field of endodontics have greatly improved the outcome and success rate of dental materials. For last three decades, there has been great interest in the development of bioactive dental material with the ability to interact and induce surrounding dental tissues to promote regeneration of pulpal and periradicular tissues. As these bioactive materials are mainly based on calcium silicates, they are also referred to as Calcium Silicate materials. The first material introduced was Mineral Tri-oxide Aggregate, which, due to its favourable biological properties, gained importance initially. However, later, due to its drawbacks, liked is colouration, long setting time and difficult manipulation, several modifications were done and newer bioactive materials, such as Biodentine, BioAggregate, Endosequence, Calcium-Enriched Mixture etc., were developed. The main applications of these materials are for pulp capping (direc t/indirec t), pulpotomy, perforation repair, resorption defects, apexogenesis and as retrograde filling materials, apexification and endodontic sealers. This review discusses the various types of bioactive materials, their composition, setting mechanism, and literature evidence for current applications.

[Bone substitute. Transplants and replacement materials--an update]. / Knochenersatz. Transplantate und Ersatzmaterialien--ein Update.

Due to the special characteristics, autologous bone for bone grafting remains the gold standard for defect filling. Besides allogenic bone transplants, as an alternative a set of bone substitutes has been established. An overview of the bone substitutes presently on the market is almost lost due to the abundance of products. The present paper gives a review of the materials available on the market. Different classification systems regarding origin, vitality, biological priority and chemical composition are described as well as the individual materials including the advantages and disadvantages. Finally, a description of tissue engineering and gene therapy gives a view of future prospective.

Comparison of the outcomes of blowout fracture repair according to the orbital implant.

PURPOSE: The clinical outcomes of blowout fracture repair classified by 2 types of orbital implants (Macropore and Medpor) were compared. PROCEDURES: The medical records of 331 patients with orbital fractures that were treated surgically by 1 surgeon at Gachon University Gil hospital, from March 2007 to March 2009, were reviewed. Patients who had diplopia or limited extraocular motion, significant enophthalmos (>2 mm), or a large fracture on a computed tomographic scan (>50% of the floor area) were enrolled. The clinical outcomes were compared between patients who received surgical repair using Macropore and those who had surgical repair using Medpor. RESULTS: One hundred six patients had surgical repair using Macropore and 225 patients were surgically treated with Medpor. Both the Macropore (n = 106) and the Medpor groups (n = 225) showed significant clinical improvement. The degree of preoperative/postoperative diplopia and limited extraocular motion was not different between the 2 groups. In addition, there was no difference in the preoperative/postoperative enophthalmos between the 2 groups. CONCLUSIONS: Both Macropore and Medpor were associated with equally safe and satisfactory patient outcomes without notable complications.

[Bone substitutes: Classification and concerns]. / Les biomatériaux de substitution osseuse : classification et intérêt.

Autograft is considered as the "gold standard" for bone reconstruction. It provides osteoinductive factors, osteogenic cells, and appropriate osteoconductive scaffold. Donor site morbidity is the main limitation of autograft. Donor disease transmission limits the use of allograft. Synthetic bone substitutes still lack osteoinductive or osteogenic properties. Composite bone substitutes combining synthetic scaffold and biochemical substances initiating proliferation and cell differentiation, and possibly osteogenesis. Bone substitutes and grafts intended for clinical use are listed.

Bone formation with various bone graft substitutes in critical-sized rat calvarial defect.

OBJECTIVE: This histomorphometric study compared the efficacy of a new bone graft substitute (N-HA) derived from hen eggshell, consisted of submicron scale porous hydroxyapatite structure, in the healing of 8 mm diameter critical size defects in rat calvaria. We compared N-HA alone or in combination with calcium sulfate (CS), with a commercial bone substitute, anorganic bovine bone (Bio-Oss, BO). MATERIAL AND METHODS: Critical size defects were created in calvaria of 56 adult Sprague-Dawley rats. Animals were divided into four groups and treated with (1) unfilled defects, (2) N-HA grafts, (3) BO grafts and (4) N-HA/CS grafts. The percentage of new bone formed (NB%) was evaluated histomorphometrically after 6 and 12 weeks. RESULTS: The N-HA group exhibited more new bone formation compared with other groups at 6 and 12 weeks. Histomorphometric analysis showed greater NB% in N-HA group (11.2% at 4 weeks and 19.2% at 12 weeks) compared with those in unfilled (3.9% at 6 weeks and 6.4% at 12 weeks), BO-treated (6.4% at 6 weeks and 8.2% at 12 weeks) and N-HA/CS-treated (6.3% at 6 weeks and 12.6% at 12 weeks) groups. The N-HA group showed significant differences in NB% compared with unfilled group at 6 weeks (P=0.016), unfilled and BO-treated groups at 12 weeks (P=0.001). The addition of CS did not enhance the NB% compared with defects grafted with N-HA alone. CONCLUSION: N-HA was an osteoconductive bone substitute for treating osseous defects in critical size defects of rat calvaria.

Revisiting the hopeless ridge: Part II--Inductive orthopedic allograft applied to dental implant regeneration.

Part I of "Revisiting the Hopeless Ridge" highlighted the higher complication rates, greater resorption profile, and lower implant success rates associated with autogenous block grafts. The conclusions described in that article were based on a comprehensive literature review, rather than an individual clinician's experience in clinical practice. Additionally, the idea that such grafts were the gold standard for traditional dental implant-associated bone regeneration was challenged. This article explores the advantageous properties of new commercially available allograft bone in a variety of clinical applications. One such product that combines demineralized bone with lecithin is reviewed, and two case reports using it are presented.

Clinical Application of Antimicrobial Bone Graft Substitute in Osteomyelitis Treatment: A Systematic Review of Different Bone Graft Substitutes Available in Clinical Treatment of Osteomyelitis.

Osteomyelitis is a common occurrence in orthopaedic surgery, which is caused by different bacteria. Treatment of osteomyelitis patients aims to eradicate infection by debridement surgery and local and systemic antibiotic therapy. Local treatment increases success rates and can be performed with different antimicrobial bone graft substitutes. This review is performed to assess the level of evidence of synthetic bone graft substitutes in osteomyelitis treatment. According to the PRISMA statement for reporting systematic reviews, different types of clinical studies concerning treatment of osteomyelitis with bone graft substitutes are included. These studies are assessed on their methodological quality as level of evidence and bias and their clinical outcomes as eradication of infection. In the fifteen included studies, the levels of evidence were weak and in ten out of the fifteen studies there was a moderate to high risk of bias. However, first results of the eradication of infection in these studies showed promising results with their relatively high success rates and low complication rates. Due to the low levels of evidence and high risks of bias of the included studies, these results are inconclusive and no conclusions regarding the performed clinical studies of osteomyelitis treatment with antimicrobial bone graft substitutes can be drawn.

The effect of biomimetic apatite structure on osteoblast viability, proliferation, and gene expression.

The conventional biomimetic apatite coating process can be accelerated by immersing substrates into concentrated simulated body fluid (5 x SBF) at 37 degrees C to form an initial coating of apatite precursor spheres, and transform the precursors into plate-like apatite structures. Depending on processing parameters, different apatite structures can be created over the same substrate. The purpose of this study is to investigate the effects of the different apatite microenvironment on cell spreading, viability, proliferation, and gene expression. MC3T3-E1 preosteoblasts were cultured on five surfaces: conventional apatite (CA), precursor apatite spheres (PreA), large plate-like apatites (LgA), small plate-like apatites (SmA), and tissue culture grade polystyrene (TCPS). PreA induced significantly higher cell death during the first two weeks. TCPS supported more uniform spreading (1 day) and higher proliferation (2 weeks) than CA, LgA, and SmA. Apatites restricted spreading and promoted the extension of cellular projections along the textured surfaces under confocal microscopy observation. By 3 weeks, LgA induced highest expression of mature osteogenic markers osteocalcin (OCN) and bone sialoprotein (BSP) in both regular and osteogenic culture media based on quantitative real-time RT-PCR. The results of this study suggest differential cell responses to subtle changes in apatite microenvironment.

Dental devices; reclassification of tricalcium phosphate granules and classification of other bone grafting material for dental bone repair. Final rule.

The Food and Drug Administration (FDA) is reclassifying tricalcium phosphate (TCP) granules for dental bone repair from class III to class II (special controls), classifying into class II (special controls) other bone grafting material for dental indications, and revising the classification name and identification of the device type. Bone grafting materials that contain a drug that is a therapeutic biologic will remain in class III and continue to require a premarket approval application. The classification identification includes materials such as hydroxyapatite, tricalcium phosphate, polylactic and polyglycolic acids, or collagen. This action is being taken to establish sufficient regulatory controls that will provide reasonable assurance of the safety and effectiveness of these devices. Elsewhere in this issue of the Federal Register, FDA is announcing the availability of the guidance document that will serve as the special control for the class II devices.

Ordinary and Activated Bone Grafts: Applied Classification and the Main Features.

Bone grafts are medical devices that are in high demand in clinical practice for substitution of bone defects and recovery of atrophic bone regions. Based on the analysis of the modern groups of bone grafts, the particularities of their composition, the mechanisms of their biological effects, and their therapeutic indications, applicable classification was proposed that separates the bone substitutes into "ordinary" and "activated." The main differential criterion is the presence of biologically active components in the material that are standardized by qualitative and quantitative parameters: growth factors, cells, or gene constructions encoding growth factors. The pronounced osteoinductive and (or) osteogenic properties of activated osteoplastic materials allow drawing upon their efficacy in the substitution of large bone defects.

A thorough physicochemical characterisation of 14 calcium phosphate-based bone substitution materials in comparison to natural bone.

Fourteen different synthetic or biological bone substitution materials were characterised by high-resolution X-ray diffractometry, infrared spectroscopy, thermogravimetry, and scanning electron microscopy. Thus, the main parameters chemical composition, crystallinity, and morphology were determined. The results are compared with natural bone samples. The materials fall into different classes: Chemically treated bone, calcined bovine bone, algae-derived hydroxyapatite, synthetic hydroxyapatite, peptide-loaded hydroxyapatite, and synthetic beta-TCP ceramics.

[Surgical techniques used in the revision of hip prostheses]. / Operatieve technieken bij het reviseren van heupprothesen.

The most common cause of failure of cemented and cementless total hip arthroplasties is aseptic loosening, a slow but progressive process that often results in loss of bone stock. The diagnosis of loosening of the prosthetic component is difficult and depends mainly on migration and change in position of the prosthesis and the appearance of clear zones around the prosthesis on X-ray photographs. The key problem in revision surgery is how to manage the periprosthetic bone loss. Controversy exists about the best treatment for bone stock defects. The various techniques are directed at restoration of the hip mechanics, restoration of the defects in the osseous wall, replacement of the resorbed bone and thus restoration of the functional stability of the joint.

Comparison of the effectiveness of two different bone substitute materials for socket preservation after tooth extraction: a controlled clinical study.

The aim of this study was to compare the effectiveness of two bone substitute materials for socket preservation after tooth extraction. Extraction sockets in 10 patients were filled with either inorganic bovine bone material (Bio-Oss) or with synthetic material consisting of hydroxyapatite and silicon dioxide (NanoBone). Extraction sockets without filling served as the control. The results demonstrate the effectiveness of the presented protocol for socket preservation and that the choice of a suitable bone substitute material is crucial. The dimensions of the alveolar ridge were significantly better preserved with Bio-Oss than with NanoBone or without treatment. Bio-Oss treatment resulted in better bone quality and quantity for successful implant placement.

The use of bone graft substitutes in large cancellous voids: any specific needs?

Bone graft is the second most common transplantation tissue, with blood being by far the commonest. Autograft is considered ideal for grafting procedures, providing osteoinductive growth factors, osteogenic cells and an osteoconductive scaffold. Limitations, however, exist regarding donor site morbidity and graft availability. Allograft on the other hand poses the risk of disease transmission. Synthetic graft substitutes lack osteoinductive or osteogenic properties. Composite grafts combine scaffolding properties with biological elements to stimulate cell proliferation and differentiation and eventually osteogenesis. We present here an overview of bone graft substitutes available for clinical application in large cancellous voids.

Classification of osseointegrated implant surfaces: materials, chemistry and topography.

Since the founding of the osseointegration concept, the characteristics of the interface between bone and implant, and possible ways to improve it, have been of particular interest in dental and orthopaedic implant research. Making use of standardized tools of analysis and terminology, we present here a standardized characterization code for osseointegrated implant surfaces. This code describes the chemical composition of the surface, that is, the core material, such as titanium, and its chemical or biochemical modification through impregnation or coating. This code also defines the physical surface features, at the micro- and nanoscale, such as microroughness, microporosity, nanoroughness, nanotubes, nanoparticles, nanopatterning and fractal architecture. This standardized classification system will allow to clarify unambiguously the identity of any given osseointegrated surface and help to identify the biological outcomes of each surface characteristic.

Bone materials available for alveolar grafting.

The restoration of bony defects has followed an interesting course through history. From the early use of animal materials to bone grown in the laboratory, the goal of restoring bony defects has generated ingenuity in solving these significant clinical challenges.

[Biomaterials in articular cartilage lesions repair]. / Biomaterialy w leczeniu uszkodzen chrzastki stawowej.

Osteoarthritic symptoms following articular cartilage injuries are the most common musculoskeletal system disease. The treatment possibilities search for methods to restore and bring back the function of injured joint surfaces. Recent trend heads for creation of biocompatible matrices (scaffolds) based on natural and synthetic polimers. This study presents currently used biomaterials in the sphere of their usefulness in articular cartilage lesions repair. Both natural and synthetic materials have been researched in experimental and clinical studies. Naturally- derived protein polymers, such as collagen, fibrin, gelatin and carbohydrate polymers containing polylactide and polyglycolic acid, hialuronan, agarose, alginate, chitosan can be distinguished. Synthetic materials are represented by carbon fibers, Dacron and Teflon matrices. Scaffolds fabrication techniques include fiber-bonding, particulate leaching, freeze- drying and particles aggregation. Due to different polymers' properties selection of a scaffold depends on an appropriate matrix parameters. The most valuable characteristics are biocompatibility, porosity, mechanical resistance and bioabsorbability. Notwithstanding, several experimental and clinical studies there still exists the need for one simple and inexpensive polymer- based method that would bring satisfactory results in the area of joint cartilage repair.