Ionic Dissolution Products of NovaBone® Promote Osteoblastic Proliferation via Influences on the Cell Cycle

Sol-Gel Technologies to Obtain Advanced Bioceramics for Dental Therapeutics

The aim of this work is to review the application of bioceramic materials in the context of current regenerative dentistry therapies, focusing on the latest advances in the synthesis of advanced materials using the sol-gel methodology. Chemical synthesis, processing and therapeutic possibilities are discussed in a structured way, according to the three main types of ceramic materials used in regenerative dentistry: bioactive glasses and glass ceramics, calcium phosphates and calcium silicates. The morphology and chemical composition of these bioceramics play a crucial role in their biological properties and effectiveness in dental therapeutics. The goal is to understand their chemical, surface, mechanical and biological properties better and develop strategies to control their pore structure, shape, size and compositions. Over the past decades, bioceramic materials have provided excellent results in a wide variety of clinical applications related to hard tissue repair and regeneration. Characteristics, such as their similarity to the chemical composition of the mineral phase of bones and teeth, as well as the possibilities offered by the advances in nanotechnology, are driving the development of new biomimetic materials that are required in regenerative dentistry. The sol-gel technique is a method for producing synthetic bioceramics with high purity and homogeneity at the molecular scale and to control the surfaces, interfaces and porosity at the nanometric scale. The intrinsic nanoporosity of materials produced by the sol-gel technique correlates with the high specific surface area, reactivity and bioactivity of advanced bioceramics.

MagnetOs, Vitoss, and Novabone in a Multi-endpoint Study of Posterolateral Fusion: A True Fusion or Not?

STUDY DESIGN

This study was a multi-endpoint analysis of bone graft substitutes implanted as a standalone graft in a clinically relevant Ovine model of instrumented posterolateral spinal fusion (PLF).

OBJECTIVE

The objective of this study was to obtain high-quality evidence on the efficacy of commercial bone graft substitutes compared with autograft in instrumented PLF using a state-of-the-art model with a complete range of assessment techniques.

SUMMARY OF BACKGROUND DATA

Preclinical and clinical data on the quality of spinal fusions obtained with bone graft substitutes are often limited. Calcium phosphates with submicron topography have shown promising results in PLF, as these are able to induce bone formation in tissues distant from the host bone, which facilitates bony union.

METHODS

Nine female, skeletally mature sheep (4-5 y) underwent posterior pedicle screw/rods instrumented PLF at L2-L3 and L4-L5 using the following bone graft materials as a standalone graft per spinal segment: (1) biphasic calcium phosphate with submicron topography (BCP<µm), (2) 45S5 Bioglass (BG), and (3) collagen-β-tricalcium phosphate with a 45S5 Bioglass adjunct (TCP/BG). Autograft bone (AB) was used as a positive control treatment. Twelve weeks after implantation, the spinal segments were evaluated by fusion assessment (manual palpation, x-ray, micro-computed tomography, and histology), fusion mass volume quantification (micro-computed tomography), range of motion (ROM) testing, histologic evaluation, and histomorphometry.

RESULTS

Fusion assessment revealed equivalence between AB and BCP<µm by all fusion assessment methods, whereas BG and TCP/BG led to significantly inferior results. Fusion mass volume was highest for BCP<µm, followed by AB, BG, and TCP/BG. ROM testing determined equivalence for spinal levels treated with AB and BCP<µm, while BG and TCP/BG exhibited higher ROM. Histologic evaluation revealed substantial bone formation in the intertransverse regions for AB and BCP<µm, whereas BG and TCP/BG grafts contained fibrous tissue and minimal bone formation. Histologic observations were supported by the histomorphometry data.

CONCLUSIONS

This study reveals clear differences in efficacy between commercially available bone graft substitutes, emphasizing the importance of clinically relevant animal models with multiendpoint analyses for the evaluation of bone graft materials. The results corroborate the efficacy of calcium phosphate with submicron topography, as this was the only material that showed equivalent performance to autograft in achieving spinal fusion.

Efeito do produto iônico do biovidro 60S na diferenciação osteogênica de células-tronco mesenquimais do tecido adiposo de cães

O objetivo do presente trabalho foi avaliar o produto iônico do biovidro 60S (BV60S) na diferenciação osteogênica de células-tronco mesenquimais de origem adiposa (CTM-AD) de cães. As CTM-AD foram diferenciadas sem OSTe com o produto iônico (PI OST) por sete, 14 e 21 dias. Avaliou-se o MTT, a fosfatase alcalina (FA), o colágeno, mineralização e as expressões de osterix (OSX), sialoproteína óssea (BSP), osteonectina (ON) e osteocalcina (OC). O grupo PI OSTmostrou menor conversão de MTT aos sete dias e maior conversão aos 21 dias. A atividade de FA foi maior no grupo OST, aos 14 e 21 dias. A síntese de colágeno foi maior no grupo OST aos sete e 21 dias. Verificou-se maior área mineralizada no grupo PI OSTem todos os tempos. Não houve diferenças nas expressões de OSX e OC entre os grupos. Observou-se maior expressão de BSP no grupo PI OST, aos 14 e 21 dias. A expressão de ON foi maior no grupo OST aos 14 dias. Concluiu-se que o produto iônico do BV60S favorece a osteogênese in vitro de CTM-AD de cães.

Preconditioned 70S30C bioactive glass foams promote osteogenesis in vivo

Bioactive glass scaffolds (70S30C; 70% SiO2 and 30% CaO) produced by a sol-gel foaming process are thought to be suitable matrices for bone tissue regeneration. Previous in vitro data showed bone matrix production and active remodelling in the presence of osteogenic cells. Here we report their ability to act as scaffolds for in vivo bone regeneration in a rat tibial defect model, but only when preconditioned. Pretreatment methods (dry, pre-wetted or preconditioned without blood) for the 70S30C scaffolds were compared against commercial synthetic bone grafts (NovaBone® and Actifuse®). Poor bone ingrowth was found for both dry and wetted sol-gel foams, associated with rapid increase in pH within the scaffolds. Bone ingrowth was quantified through histology and novel micro-CT image analysis. The percentage bone ingrowth into dry, wetted and preconditioned 70S30C scaffolds at 11 weeks were 10±1%, 21±2% and 39±4%, respectively. Only the preconditioned sample showed above 60% material-bone contact, which was similar to that in NovaBone and Actifuse. Unlike the commercial products, preconditioned 70S30C scaffolds degraded and were replaced with new bone. The results suggest that bioactive glass compositions should be redesigned if sol-gel scaffolds are to be used without preconditioning to avoid excess calcium release.

Use of the NovaBone augmentation material in the treatment of chronic periodontitis. Preliminary communication

The pilot study deals with the clinical results of the regenerative therapeutical method in intraosseous periodontal defects done by surgical augmentation procedure using a material of a new generation prepared on the basis of a bioactive glass. A group of 10 individuals were treated properly for chronic periodontitis. Some of treated infraalveolar periodontal lesions, both periodontal pockets and interradicular defects, persisted or recurred in posterior teeth. In order to eliminate them they were indicated for advanced periodontal surgery or regenerative surgical therapy stimulating healing processes of supportive tissues, mostly alveolar bone around treated teeth. Relevant clinical parameters, i. e. values of the pocket depth, gingival recession, and loss of attachment were evaluated before and after the periodontal surgery and compared with each other. The therapy led to significant improvement of clinical parameters in terms of the reduction of pocket depth and loss of attachment values.