Biomaterials for Periodontal Regeneration

Advances in harnessing biological macromolecules for periodontal tissue regeneration: A review

Periodontitis is a chronic multifactorial inflammatory oral disease that can lead to gingival recession, destruction of the periodontal ligament, alveolar bone loss, and tooth loss. Solutions for periodontal tissue regeneration utilize biological macromolecules, including natural ones (such as collagen (COL), alginate (ALG), chitosan (CS), silk fibroin (SF), hyaluronic acid (HA), etc.), inorganic ones (such as hydroxyapatite (HAp), β-tricalcium phosphate (β-TCP), bioactive glass (BG), etc.), synthetic, composite, and nanomaterials. Carrier materials, including hydrogels, nanofibers, nanoparticles, microneedles, and thin films, are used to effectively deliver therapeutic agents and biological factors such as stem cells, bioactive molecules, and genes, so as to promote the elimination of bacteria and tissue regeneration at the damaged periodontal sites. This review mainly focuses on the latest progress of biological macromolecules and tissue engineering technologies in periodontal regeneration in recent years. It aims to inspire the design and development of innovative biomaterials and delivery systems for novel regenerative periodontal treatments.

Biomaterials for Guided Tissue Regeneration and Guided Bone Regeneration: A Review

This review aims to provide an overview of the types of membranes, bone substitutes, and mucosal substitutes used for GTR and GBR and briefly explores recent innovations for tissue regeneration and their future perspectives. Since this is a narrative review, no systematic search, meta-analysis, or statistical analysis was conducted. Using biomaterials for GTR and GBR provides a reduction in postoperative morbidity, as it contributes to less invasive clinical procedures, serving as an alternative to autogenous grafts. Moreover, randomized clinical trials (RCTs) and systematic reviews are essential for the evaluation of new biomaterials. These studies provide more robust evidence and help guide clinical practice in the selection of safer and more effective biomaterials, allowing for the personalization of treatment protocols for each patient.

Optimizing collagen-based biomaterials for periodontal regeneration: clinical opportunities and challenges

Periodontal disease (PD) is a chronic inflammatory condition that affects the teeth and their supporting tissues, ultimately culminating in tooth loss. Currently, treatment modalities, such as systemic and local administration of antibiotics, serve to mitigate the progression of inflammation yet fall short in restoring the original anatomical structure and physiological function of periodontal tissues. Biocompatible material-based tissue engineering seems to be a promising therapeutic strategy for treating PD. Collagen, a component of the extracellular matrix commonly used for tissue engineering, has been regarded as a promising biogenic material for tissue regeneration owing to its high cell-activating and biocompatible properties. The structural and chemical similarities between collagen and components of the oral tissue extracellular matrix render it a promising candidate for dental regeneration. This review explored the properties of collagen and its current applications in periodontal regeneration. We also discussed the recent progression in collagen therapies and preparation techniques. The review also scrutinizes the pros and cons associated with the application of collagen-based biomaterials in PD treatment, aiming to pave the way for future applications of collagen-based biomaterials in the management of PD.

Engineering of Bioresorbable Polymers for Tissue Engineering and Drug Delivery Applications

Herein, the recent advances in the development of resorbable polymeric-based biomaterials, their geometrical forms, resorption mechanisms, and their capabilities in various biomedical applications are critically reviewed. A comprehensive discussion of the engineering approaches for the fabrication of polymeric resorbable scaffolds for tissue engineering, drug delivery, surgical, cardiological, aesthetical, dental and cardiovascular applications, are also explained. Furthermore, to understand the internal structures of resorbable scaffolds, representative studies of their evaluation by medical imaging techniques, e.g., cardiac computer tomography, are succinctly highlighted. This approach provides crucial clinical insights which help to improve the materials' suitable and viable characteristics for them to meet the highly restrictive medical requirements. Finally, the aspects of the legal regulations and the associated challenges in translating research into desirable clinical and marketable materials of polymeric-based formulations, are presented.

Impact of Hyaluronic Acid and Other Re-Epithelializing Agents in Periodontal Regeneration: A Molecular Perspective

This narrative review delves into the molecular mechanisms of hyaluronic acid (HA) and re-epithelializing agents in the context of periodontal regeneration. Periodontitis, characterized by chronic inflammation and the destruction of tooth-supporting tissues, presents a significant challenge in restorative dentistry. Traditional non-surgical therapies (NSPTs) sometimes fail to fully manage subgingival biofilms and could benefit from adjunctive treatments. HA, with its antibacterial, antifungal, anti-inflammatory, angiogenic, and osteoinductive properties, offers promising therapeutic potential. This review synthesizes the current literature on the bioactive effects of HA and re-epithelializing agents, such as growth factors and biomaterials, in promoting cell migration, proliferation, and extracellular matrix (ECM) synthesis. By modulating signaling pathways like the Wnt/β-catenin, TGF-β, and CD44 interaction pathways, HA enhances wound healing processes and tissue regeneration. Additionally, the role of HA in facilitating cellular crosstalk between epithelial and connective tissues is highlighted, as it impacts the inflammatory response and ECM remodeling. This review also explores the combined use of HA with growth factors and cytokines in wound healing, revealing how these agents interact synergistically to optimize periodontal regeneration. Future perspectives emphasize the need for further clinical trials to evaluate the long-term outcomes of these therapies and their potential integration into periodontal treatment paradigms.

Biomaterial Scaffolds for Periodontal Tissue Engineering

Advanced periodontitis poses a significant threat to oral health, causing extensive damage and loss of both hard and soft periodontal tissues. While traditional therapies such as scaling and root planing can effectively halt the disease's progression, they often fail to fully restore the original architecture and function of periodontal tissues due to the limited capacity for spontaneous regeneration. To address this challenge, periodontal tissue engineering has emerged as a promising approach. This technology centers on the utilization of biomaterial scaffolds, which function as three-dimensional (3D) templates or frameworks, supporting and guiding the regeneration of periodontal tissues, including the periodontal ligament, cementum, alveolar bone, and gingival tissue. These scaffolds mimic the extracellular matrix (ECM) of native periodontal tissues, aiming to foster cell attachment, proliferation, differentiation, and, ultimately, the formation of new, functional periodontal structures. Despite the inherent challenges associated with preclinical testing, the intensification of research on biomaterial scaffolds, coupled with the continuous advancement of fabrication technology, leads us to anticipate a significant expansion in their application for periodontal tissue regeneration. This review comprehensively covers the recent advancements in biomaterial scaffolds engineered specifically for periodontal tissue regeneration, aiming to provide insights into the current state of the field and potential directions for future research.

Periodontists and stem cell-based therapy for alveolar bone regeneration: A national survey

BACKGROUND

Stem cell-based therapy for bone regeneration has received attention in medical settings but has not yet been used in clinical practice for treating alveolar bone defects. The objectives of this study were to explore whether periodontists had heard about this approach, and if so how, how interested they were to learn about it, which attitudes and behavioral intentions they had related to using stem cell-based grafting, and what they would like to know before using this approach.

METHODS

Anonymous survey data were collected from 481 members of the American Academy of Periodontology (response rate: 19.41%).

RESULTS

Responses showed 35.3% had heard about stem cell-based therapy, mostly from publications (9.6%) and meetings (8.3%); 76.1% wanted to learn about it through in-person continuing education (CE) courses, 68.6% in online CE courses, and 57.1% from manuals; 73% considered this approach promising; and 54.9% preferred it to traditional approaches. It was important to them that it would result in more bone volume (93%), better bone quality (90.4%), and accelerated healing (83.2%). Also, 60.1% considered it likely/very likely that they would adopt this approach, 54% that patients would prefer it, and 62.1% that it would benefit their practice. When asked what they would like to know about this approach, information about short- and long-term outcomes, cost, and logistical considerations were most frequently named.

CONCLUSIONS

These findings provide the basis to develop educational interventions for periodontists about this novel approach and inform future research activities aimed to translate this approach to clinical practice.

The Role of Fibroblasts in Skin Homeostasis and Repair

Fibroblasts are typical mesenchymal cells widely distributed throughout the human body where they (1) synthesise and maintain the extracellular matrix, ensuring the structural role of soft connective tissues; (2) secrete cytokines and growth factors; (3) communicate with each other and with other cell types, acting as signalling source for stem cell niches; and (4) are involved in tissue remodelling, wound healing, fibrosis, and cancer. This review focuses on the developmental heterogeneity of dermal fibroblasts, on their ability to sense changes in biomechanical properties of the surrounding extracellular matrix, and on their role in aging, in skin repair, in pathologic conditions and in tumour development. Moreover, we describe the use of fibroblasts in different models (e.g., in vivo animal models and in vitro systems from 2D to 6D cultures) for tissue bioengineering and the informative potential of high-throughput assays for the study of fibroblasts under different disease contexts for personalized healthcare and regenerative medicine applications.

Multifunctional Nanofibrous Hollow Microspheres for Enhanced Periodontal Bone Regeneration

Destructive periodontitis destroys alveolar bone and eventually leads to tooth loss. While guided bone regeneration, which is based on creating a physical barrier to hinder the infiltration of epithelial and connective tissues into defect sites, has been widely used for alveolar bone regeneration, its outcomes remain variable. In this work, a multifunctional nanofibrous hollow microsphere (NFHMS) is developed for enhanced alveolar bone regeneration. The NFHMS is first prepared via combining a double emulsification and a thermally induced phase separation process. Next, E7, a short peptide with high specific affinity to bone marrow-derived stem cells (BMSCs), is conjugated onto the surface of NFHMS. After that, bone forming peptide (BFP), a short peptide derived from bone morphology protein 7 is loaded in calcium phosphate (CaP) nanoparticles, which are further encapsulated in the hollow space of the NFHMS-E7 to form NFHMS-E7-CaP/BFP. The NFHMS-E7-CaP/BFP selectively promoted the adhesion of BMSCs and expelled the adhesion of fibroblasts and epithelial cells. In addition, the BFP is sustainedly released from the NFHMS-E7-CaP/BFP to enhance the osteogenesis of BMSCs. A rat challenging fenestration defect model showed that the NFHMS-E7-CaP/BFP significantly enhanced alveolar bone tissue regeneration. This work provides a novel bioengineering approach for guided bone regeneration.

Recent Advances in Scaffolds for Guided Bone Regeneration

The rehabilitation of alveolar bone defects of moderate to severe size is often challenging. Currently, the therapeutic approaches used include, among others, the guided bone regeneration technique combined with various bone grafts. Although these techniques are widely applied, several limitations and complications have been reported such as morbidity, suboptimal graft/membrane resorption rate, low structural integrity, and dimensional stability. Thus, the development of biomimetic scaffolds with tailor-made characteristics that can modulate cell and tissue interaction may be a promising tool. This article presents a critical consideration in scaffold's design and development while also providing information on various fabrication methods of these nanosystems. Their utilization as delivery systems will also be mentioned.

Clinical and radiographic evaluation of Bio-Oss granules and Bio-Oss Collagen in the treatment of periodontal intrabony defects: a retrospective cohort study

OBJECTIVE

This retrospective study aimed to analyze the clinical efficacy of two regenerative surgical methods - Bio-Oss granules combined with barrier membranes and Bio-Oss Collagen alone - and to help clinicians achieve better periodontal regeneration outcomes in the specific periodontal condition.

METHODOLOGY

Patients who underwent periodontal regeneration surgery from January 2018 to April 2022 were retrospectively screened, and their clinical and radiographic outcomes at 6 months postoperatively were analyzed. The probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), gingival recession (GR), distance from the cemento-enamel junction to the bottom of the bone defect (CEJ-BD), and depth of intrabony defects (INFRA) were recorded before the operation (T0) and 6 months after it (T1), and subsequently compared.

RESULTS

In total, 143 patients were included - 77 were placed in the Bio-Oss group and 66 were placed in the Bio-Oss Collagen group. All indicators, including PD and CAL at T1, showed significant differences compared to baseline, for both groups (P<0.001). PD reduction was greater in the group receiving the Bio-Oss Collagen treatment (P=0.042). Furthermore, in cases when the baseline PD range was 7-11 mm and the age range was 35-50 years, PD reduction was more significant for patients receiving the Bio-Oss Collagen treatment (P=0.031, 0.023). A linear regression analysis indicated that postoperative PD and CAL were positively correlated with baseline values, and that the efficacy tended to decrease with increasing age.

CONCLUSION

Both the use of Bio-Oss Collagen alone and the use of Bio-Oss granules combined with barrier membranes resulted in significant effects in the treatment of periodontal intrabony defects. The Bio-Oss Collagen treatment generated more improvements in PD than the Bio-Oss granules combined with barrier membranes, particularly within the baseline PD range of 7-11 mm and the 35-50 years age group. Additionally, age was the main factor influencing the effectiveness of regenerative surgery for intrabony defects: older individuals exhibited fewer improvements.

Effectiveness of concentrated growth factor and laser therapy on wound healing, inferior alveolar nerve injury and periodontal bone defects post-mandibular impacted wisdom tooth extraction: A randomized clinical trial

The extraction of wisdom teeth with mandibular impact frequently results in complications including damage to the inferior alveolar nerve (IAN) and malformations of the bone. The objective of this research endeavour was to assess the efficacy of low-level laser therapy and concentrated growth factor (CGF) in facilitating nerve recovery and wound healing in such instances. A total of thirty-one patients (mean age 27.52 ± 5.79 years) who presented with IAN injury after extraction were randomly assigned to one of three groups: control group (which received oral mecobalamin), CGF group (which received CGF gel applied to the extraction sockets) and laser group (which received low-level lasers (808 nm, 30 mW, 10 J/cm2 )) at the extraction site. Patients' recovery from IAN paresthesia was evaluated seven times over the course of 14 days utilizing visual analogue scale (VAS) and the pinprick test (PP). At multiple intervals following surgery, periodontal probing and bone level measurements were utilized to assess the recovery of both soft and hard tissues. The findings revealed that, compared with the control group, both the CGF and laser treatment groups exhibited a markedly greater improvement in VAS scores and wound healing of soft tissues, as well as in PP results (p < 0.001), indicating enhanced wound healing processes. Despite these improvements, there was no significant difference in wound healing outcomes between the CGF and laser groups. Notably, the CGF group showed a statistically significant improvement in healing bone defects at 30 and 90 days post-treatment compared with the control group (p = 0.003 and p = 0.004, respectively), underscoring its effectiveness in bone healing as a critical aspect of the overall wound healing process. However, in terms of other wound healing comparisons, no significant differences were observed. CGF and laser therapy significantly enhanced the healing of wounds, including soft tissue and bone recovery, in addition to accelerating the recovery of IAN injuries following mandibular wisdom tooth extraction. Although both treatments were equally effective in nerve recovery, CGF notably excelled in promoting bone healing, suggesting its pivotal role in comprehensive wound healing. This highlights that both CGF and laser therapy are viable options for not only nerve recovery but also for overall wound healing in such dental procedures.

Biomimetic Collagen Membranes as Drug Carriers of Geranylgeraniol to Counteract the Effect of Zoledronate

To counteract the effect of zoledronate and decrease the risk of osteonecrosis of the jaw (BRONJ) development in patients undergoing guided bone regeneration surgery, the use of geranylgeraniol (GGOH) has been proposed. Collagen membranes may act as biomimetical drug carriers. The objective of this study was to determine the capacity of collagen-based membranes doped with GGOH to revert the negative impact of zoledronate on the growth and differentiation of human osteoblasts. MG-63 cells were cultured on collagen membranes. Two groups were established: (1) undoped membranes and (2) membranes doped with geranylgeraniol. Osteoblasts were cultured with or without zoledronate (50 μM). Cell proliferation was evaluated at 48 h using the MTT colorimetric method. Differentiation was tested by staining mineralization nodules with alizarin red and by gene expression analysis of bone morphogenetic proteins 2 and 7, alkaline phosphatase (ALP), bone morphogenetic proteins 2 and 7 (BMP-2 and BMP-7), type I collagen (Col-I), osterix (OSX), osteocalcin (OSC), osteoprotegerin (OPG), receptor for RANK (RANKL), runt-related transcription factor 2 (Runx-2), TGF-β1 and TGF-β receptors (TGF-βR1, TGF-βR2, and TGF-βR3), and vascular endothelial growth factor (VEGF) with real-time PCR. One-way ANOVA or Kruskal-Wallis and post hoc Bonferroni tests were applied (p < 0.05). Scanning electron microscopy (SEM) observations were also performed. Treatment of osteoblasts with 50 μM zoledronate produced a significant decrease in cell proliferation, mineralization capacity, and gene expression of several differentiation markers if compared to the control (p < 0.001). When osteoblasts were treated with zoledronate and cultured on GGOH-doped membranes, these variables were, in general, similar to the control group (p > 0.05). GGOH applied on collagen membranes is able to reverse the negative impact of zoledronate on the proliferation, differentiation, and gene expression of different osteoblasts' markers.

E7-Conjugated Bio-Inspired Microspheres as a Biological Barrier for Guided Tissue Regeneration

Guided tissue regeneration (GTR), which is based on creating a physical barrier to prevent the downgrowth of epithelial and connective tissues into the defect site, has been widely used in clinical practice for periodontal regeneration for many years. However, its outcomes remain variable due to highly specific indications, the demand for proficient surgical skills, and frequent occurrence of complications. In this study, we developed a new GTR biomaterial that acts as a biological barrier for epithelial cells and fibroblasts while also serving as a scaffold for bone marrow-derived mesenchymal stem cells (BMSCs) and periodontal ligament stem cells (PDLSCs). This innovative GTR biomaterial is bioinspired injectable microspheres that are self-assembled from nanofibers, and their surfaces are conjugated with E7, a short peptide that selectively promotes BMSC and PDLSC adhesion but inhibits the attachment and spreading of epithelial cells and gingival fibroblasts. The selective affinity afforded by E7 on the surfaces of the nanofibrous microspheres facilitated the colonization of BMSCs in the periodontal defect, thereby substantially improving functional periodontal regeneration, as evidenced by enhanced new bone formation, reduced root exposure, and diminished attachment loss. The remarkable superiority of the bioinspired microspheres over conventional GTR materials in promoting periodontal regeneration underscores the potential of this innovative approach to enhance the efficacy of functional periodontal tissue regeneration.

Recent Advances in Functionalized Electrospun Membranes for Periodontal Regeneration

Periodontitis is a global, multifaceted, chronic inflammatory disease caused by bacterial microorganisms and an exaggerated host immune response that not only leads to the destruction of the periodontal apparatus but may also aggravate or promote the development of other systemic diseases. The periodontium is composed of four different tissues (alveolar bone, cementum, gingiva, and periodontal ligament) and various non-surgical and surgical therapies have been used to restore its normal function. However, due to the etiology of the disease and the heterogeneous nature of the periodontium components, complete regeneration is still a challenge. In this context, guided tissue/bone regeneration strategies in the field of tissue engineering and regenerative medicine have gained more and more interest, having as a goal the complete restoration of the periodontium and its functions. In particular, the use of electrospun nanofibrous scaffolds has emerged as an effective strategy to achieve this goal due to their ability to mimic the extracellular matrix and simultaneously exert antimicrobial, anti-inflammatory and regenerative activities. This review provides an overview of periodontal regeneration using electrospun membranes, highlighting the use of these nanofibrous scaffolds as delivery systems for bioactive molecules and drugs and their functionalization to promote periodontal regeneration.

Stem cell therapies for periodontal tissue regeneration: A meta-analysis of clinical trials

Objective

Stem cell therapy in periodontal tissue regeneration has reported optimistic regenerative results; evidence supporting its superiority over conventional methods is still ambiguous. Therefore, this meta-analysis aims to evaluate the therapeutic effects of stem cells in human periodontal regeneration.

Design

A literature search was conducted to retrieve relevant articles on periodontal regeneration in stem cell therapy. A meta-analysis of the studies was conducted using the Stata software.

Results

Fifteen studies that examined the effect of stem cell therapies on periodontal tissue regeneration in 369 patients were selected from databases. Regardless of the various types of cells, both odontogenic (periodontal ligament, dental pulp, gingiva stem cell) and non-odontogenic (bone marrow, periosteum-derived, and umbilical cord stem cells), the cell therapies witnessed significant improvements in terms of clinical attachment level (SMD, -0.67; 95CI, -0.90 to -0.43), probing depth (SMD, -0.76; 95% CI, -1.21 to - 0.31), radiographic intrabony defect depth (SMD, -0.87; 95% CI, -1.52 to -0.23), and histomorphometric analysis of mineralized bone (SMD, 0.80; 95% CI, 0.42 to 1.19) when compared to traditional without-cell treatment in patients. However, evidence on gingival recession, alveolar thickness gain, bone mineral density of bone core, and bone volume fraction of bone core outcomes did not reach statistical significance.

Conclusions

Evidence suggests that the implementation of stem cell therapies in reconstructing compromised gingiva and alveolar bone tissue produces positive outcomes compared with conventional approaches. However, further well-designed investigations are needed to comprehensively identify the most effective source of cells and biomaterials for each case.

Are Local Drug Delivery Systems a Challenge in Clinical Periodontology?

Placing antimicrobial treatments directly in periodontal pockets is an example of the local administration of antimicrobial drugs to treat periodontitis. This method of therapy is advantageous since the drug concentration after application far surpasses the minimum inhibitory concentration (MIC) and lasts for a number of weeks. As a result, numerous local drug delivery systems (LDDSs) utilizing various antibiotics or antiseptics have been created. There is constant effort to develop novel formulations for the localized administration of periodontitis treatments, some of which have failed to show any efficacy while others show promise. Thus, future research should focus on the way LDDSs can be personalized in order to optimize future clinical protocols in periodontal therapy.

Histological and Histomorphometric Evaluation of Implanted Photodynamic Active Biomaterials for Periodontal Bone Regeneration in an Animal Study

Recently, our group developed two different polymeric biomaterials with photodynamic antimicrobial surface activity for periodontal bone regeneration. The aim of the present study was to analyze the biocompatibility and osseointegration of these materials in vivo. Two biomaterials based on urethane dimethacrylate (BioM1) and tri-armed oligoester-urethane methacrylate (BioM2) that additionally contained ß-tricalcium phosphate and the photosensitizer mTHPC (meso-tetra(hydroxyphenyl)chlorin) were implanted in non-critical size bone defects in the femur (n = 16) and tibia (n = 8) of eight female domestic sheep. Bone specimens were harvested and histomorphometrically analyzed after 12 months. BioM1 degraded to a lower extent which resulted in a mean remnant square size of 17.4 mm², while 12.2 mm² was estimated for BioM2 (p = 0.007). For BioM1, a total percentage of new formed bone by 30.3% was found which was significant higher compared to BioM2 (8.4%, p < 0.001). Furthermore, BioM1 was afflicted by significant lower soft tissue formation (3.3%) as compared to BioM2 (29.5%). Additionally, a bone-to-biomaterial ratio of 81.9% was detected for BioM1, while 8.5% was recorded for BioM2. Implantation of BioM2 caused accumulation of inflammatory cells and led to fibrous encapsulation. BioM1 (photosensitizer-armed urethane dimethacrylate) showed favorable regenerative characteristics and can be recommended for further studies.

Biomimicry and 3D-Printing of Mussel Adhesive Proteins for Regeneration of the Periodontium-A Review

Innovation in the healthcare profession to solve complex human problems has always been emulated and based on solutions proven by nature. The conception of different biomimetic materials has allowed for extensive research that spans several fields, including biomechanics, material sciences, and microbiology. Due to the atypical characteristics of these biomaterials, dentistry can benefit from these applications in tissue engineering, regeneration, and replacement. This review highlights an overview of the application of different biomimetic biomaterials in dentistry and discusses the key biomaterials (hydroxyapatite, collagen, polymers) and biomimetic approaches (3D scaffolds, guided bone and tissue regeneration, bioadhesive gels) that have been researched to treat periodontal and peri-implant diseases in both natural dentition and dental implants. Following this, we focus on the recent novel application of mussel adhesive proteins (MAPs) and their appealing adhesive properties, in addition to their key chemical and structural properties that relate to the engineering, regeneration, and replacement of important anatomical structures in the periodontium, such as the periodontal ligament (PDL). We also outline the potential challenges in employing MAPs as a biomimetic biomaterial in dentistry based on the current evidence in the literature. This provides insight into the possible increased functional longevity of natural dentition that can be translated to implant dentistry in the near future. These strategies, paired with 3D printing and its clinical application in natural dentition and implant dentistry, develop the potential of a biomimetic approach to overcoming clinical problems in dentistry.