Periodontal regeneration induced by porous alpha-tricalcium phosphate with immobilized basic fibroblast growth factor in a canine model of 2-wall periodontal defects

Periodontal Wound Healing and Regeneration: Insights for Engineering New Therapeutic Approaches

Periodontitis is a widespread inflammatory disease that leads to loss of the tooth supporting periodontal tissues. The few therapies available to regenerate periodontal tissues have high costs and inherent limitations, inspiring the development of new approaches. Studies have shown that periodontal tissues have an inherent capacity for regeneration, driven by multipotent cells residing in the periodontal ligament (PDL). The purpose of this review is to describe the current understanding of the mechanisms driving periodontal wound healing and regeneration that can inform the development of new treatment approaches. The biologic basis underlying established therapies such as guided tissue regeneration (GTR) and growth factor delivery are reviewed, along with examples of biomaterials that have been engineered to improve the effectiveness of these approaches. Emerging therapies such as those targeting Wnt signaling, periodontal cell delivery or recruitment, and tissue engineered scaffolds are described in the context of periodontal wound healing, using key in vivo studies to illustrate the impact these approaches can have on the formation of new cementum, alveolar bone, and PDL. Finally, design principles for engineering new therapies are suggested which build on current knowledge of periodontal wound healing and regeneration.

Regenerative benefits of using growth factors in treatment of periodontal defects: A systematic review and meta-analysis with Trial Sequential Analysis on preclinical studies

The ultimate goal in periodontal treatments is to achieve a functional and anatomical regeneration of the lost tissues. Numerous studies have in some way illustrated the beneficial effects of biologic modifiers in this process, yet they are subject to a rather large degree of diversity in their results. Thanks to the promising outcomes of bioengineering techniques in the field of periodontal regeneration, this systematic review aims to evaluate the effect of various biologic modifiers used in periodontal defects of animal models. Electronic databases (Medline, Scopus, Embase, Web of Science, and Google Scholar) were searched (March 2010-December 2020) for every study that used biomolecules for regeneration of periodontal osseous defects in animal models. Regenerated bone height or area, new cementum, new connective tissues, new regenerated periodontal ligament and the dimensions of epithelial attachment (either in mm/mm² or percentage) were the investigated outcomes. The risk of bias of the included studies was assessed using the SYRCLE tool. In closing, there was a meta-analysis carried out on the outcomes of interest. Trial Sequential Analysis was also carried out to figure out the power of meta-analytic outcomes. From 1995 studies which were found in the initial search, 34 studies were included in this review, and 20 of them were selected for the meta-analysis. The eligible studies were categorized according to the morphology of the experimental periodontal defects as one-, two-, and three-wall intrabony defects; furcation defects, and recession-type defects. The most studied biomolecules were rhFGF-2, rhGDF-5, platelet-derived growth factor, bone morphogenetic protein-2, and enamel matrix derivative (EMD). Based on the meta-analysis findings, combined application of biomolecules with regenerative treatments could improve new bone and cementum formation near 1 mm when compared to the control groups in one, two and three-wall intrabony defect models (p < 0.001). In furcation grade II defect, the addition of biomolecules was observed to enhance bone area gain and cementum height regeneration up to almost 2 mm (p < 0.001). Trial Sequential Analysis results confirmed the significant effect in the aforementioned meta-analyses. In cases of the buccal recession model, the application of rhFGF-2 and rhGDF-5 decreased the dimension of epithelial attachments besides regenerative advantages on bone and cementum formation, but EMD deposition exerted no inhibitory effect on epithelial down-growth. Application of biologic modifiers especially FGF-2 and GDF-5, could positively improve the regeneration of periodontal tissues, particularly cementum and bone in animal models. Trial Sequential Analysis confirmed the results but the power of the evidences was high just in some subgroup meta-analyses, like bone and cementum regeneration in furcation grade II model and cementum regeneration in one-wall intrabony defects. The outcomes of this study can potentially endow clinicians with guidelines for the appropriate application of growth factors in periodontal regenerative therapies.

The Role of Type 2 Fibroblast Growth Factor in Periodontal Therapy

The prevalence of periodontitis is around 20-50% in the global population. If it is not treated, it can cause tooth loss. Periodontal treatment aims at preserving the patient's teeth from various damages, including infection control and restoring lost periodontal tissue. The periodontium has great biological regenerative potential, and several biomaterials can be used to improve the outcome of periodontal treatment. To achieve the goal of periodontal tissue regeneration, numerous studies have used fibroblast growth factor 2 (FGF2) to stimulate the regeneration of both the soft tissue and bone. FGF2 induced a significant increment in the percentage of bone fill, bone mineral levels of the defect sites, length of the regenerated periodontal ligament, angiogenesis, connective tissue formation on the root surface, formation of dense fibers bound to the alveolar bone and newly synthesized cementum in teeth. This review will open further avenues to better understand the FGF2 therapy for periodontal regeneration.

In vitro and in vivo effectiveness of a novel injectable calcitonin-loaded collagen/ceramic bone substitute

This study aimed to evaluate the effectiveness of a novel calcitonin-loaded calcium phosphate composite bone cement in vitro and in vivo. The novel composite bone cements were composed of NuROs injectable bone graft substitute, type I collagen, and/or salmon calcitonin. The setting time, porosity, wettability, compressive strength, compressive modulus, and crystallographic structures of cement specimens were determined. Degradation rate, calcitonin release rate, and osteoinductivity were assessed in vitro. In addition, osteogenic effect was examined in a rabbit model of femoral defect. The results revealed that addition of collagen/calcitonin did not substantially alter physical properties and degradation rate of bone cement specimens. Calcitonin was released into culture medium in a two-phase manner. Osteogenic effect of conditioned medium derived from calcitonin containing bone cement was observed. Finally, de novo bone growth and bone mineralization across the bone defect area were observed in rabbits after implantation of composite bone cement specimens. In conclusion, this novel calcitonin-loaded composite calcium phosphate bone cement exhibits biocompatibility, bioresorbability, osteoinductivity, and osteoconductivity, which may be suitable for clinical use.

Recent advances in periodontal regeneration: A biomaterial perspective

Periodontal disease (PD) is one of the most common inflammatory oral diseases, affecting approximately 47% of adults aged 30 years or older in the United States. If not treated properly, PD leads to degradation of periodontal tissues, causing tooth movement, and eventually tooth loss. Conventional clinical therapy for PD aims at eliminating infectious sources, and reducing inflammation to arrest disease progression, which cannot achieve the regeneration of lost periodontal tissues. Over the past two decades, various regenerative periodontal therapies, such as guided tissue regeneration (GTR), enamel matrix derivative, bone grafts, growth factor delivery, and the combination of cells and growth factors with matrix-based scaffolds have been developed to target the restoration of lost tooth-supporting tissues, including periodontal ligament, alveolar bone, and cementum. This review discusses recent progresses of periodontal regeneration using tissue-engineering and regenerative medicine approaches. Specifically, we focus on the advances of biomaterials and controlled drug delivery for periodontal regeneration in recent years. Special attention is given to the development of advanced bio-inspired scaffolding biomaterials and temporospatial control of multi-drug delivery for the regeneration of cementum-periodontal ligament-alveolar bone complex. Challenges and future perspectives are presented to provide inspiration for the design and development of innovative biomaterials and delivery system for new regenerative periodontal therapy.