New Perspectives in the Use of Biomaterials for Periodontal Regeneration

The effect of dental material type and masticatory forces on periodontitis-derived subgingival microbiomes

Restorative dental materials can frequently extend below the gingival margin, serving as a potential haven for microbial colonization, and altering the local oral microbiome to ignite infection. However, the contribution of dental materials on driving changes of the composition of the subgingival microbiome is under-investigated. This study evaluated the microbiome-modulating properties of three biomaterials, namely resin dental composites (COM), antimicrobial piezoelectric composites (BTO), and hydroxyapatite (HA), using an optimized in vitro subgingival microbiome model derived from patients with periodontal disease. Dental materials were subjected to static or cyclic loading (mastication forces) during biofilm growth. Microbiome composition was assessed by 16S rRNA gene sequencing. Dysbiosis was measured in terms of subgingival microbial dysbiosis index (SMDI). Biomaterials subjected to cyclic masticatory loads were associated with enhanced biofilm viability except on the antibacterial composite. Biomaterials held static were associated with increased biofilm biomass, especially on HA surfaces. Overall, the microbiome richness (Chao index) was similar for all the biomaterials and loading conditions. However, the microbiome diversity (Shannon index) for the HA beams was significantly different than both composites. In addition, beta diversity analysis revealed significant differences between composites and HA biomaterials, and between both loading conditions (static and cyclic). Under static conditions, microbiomes formed over HA surfaces resulted in increased dysbiosis compared to composites through the enrichment of periopathogens, including Porphyromonas gingivalis, Porphyromonas endodontalis, and Fretibacterium spp., and depletion of commensals such as Granulicatella and Streptococcus spp. Interestingly, cyclic loading reversed the dysbiosis of microbiomes formed over HA (depletion of periopathogenes) but increased the dysbiosis of microbiomes formed over composites (enrichment of Porphyromonas gingivalis and Fusobacterim nucleatum). Comparison of species formed on both composites (control and antibacterial) showed some differences. Commercial composites enriched Selenomonas spp. and depleted Campylobacter concisus. Piezoelectric composites effectively controlled the microbiome viability without significantly impacting the species abundance. Findings of this work open new understandings of the effects of different biomaterials on the modulation of oral biofilms and the relationship with oral subgingival infections.

Critical-size defects reconstruction with four different bone grafts associated with e-PTFE membrane: A histomorphometric experimental in vivo study

OBJECTIVES

The goal of this study was to assess the newly formed bone and the remnant biomaterial by comparing four different bone grafts used to treat critical-size defects, associated or not with the non-resorbable membrane.

MATERIALS AND METHODS

Two calvaria critical-size bone defects were created in 50 male Wistar rats. They were divided into blood (G1), autogenous (G2), bioglass (G3), hydroxyapatite (G4), and xenograft (G5) groups, associated or not with e-PTFE. The experimental periods were 15 and 45 days. Sections were prepared for histomorphometric assessment. All data were analyzed by the mixed-effects model with multiple comparisons (significance level, p < .05).

RESULTS

A similar level of new bone was observed for all groups, associated with a high level of vascularization. G1 and G2 ensured sovereignty over the greater quantity of new bone. A non-significant result was reported comparing groups with and without membranes. No significant result was found between the experimental synthetic biomaterials (G3 and G4). G5L achieved 22.0% of new bone after 45 days (p > .05). All groups had a stable volume of biomaterial kept in the short term (p > .05). G2 was the best material for new bone formation and final volume of biomaterial, followed by G4 < G5 < G3. Thus, it is possible that G4 had a better degradation profile among the experimental groups.

CONCLUSIONS

The best results were found in the autogenous group, with higher resorption and integration; non-significative new bone was found among the experimental groups; and the regeneration of critical bone defects using an e-PTFE barrier did not present significant results on new bone formation.

The Association of Nanostructured Carbonated Hydroxyapatite with Denatured Albumin and Platelet-Rich Fibrin: Impacts on Growth Factors Release and Osteoblast Behavior

Platelet-rich Fibrin (PRF), a second-generation blood concentrate, offers a versatile structure for bone regeneration due to its composition of fibrin, growth factors, and cytokines, with adaptations like denatured albumin-enriched with liquid PRF (Alb-PRF), showing potential for enhanced stability and growth factor dynamics. Researchers have also explored the combination of PRF with other biomaterials, aiming to create a three-dimensional framework for enhanced cell recruitment, proliferation, and differentiation in bone repair studies. This study aimed to evaluate a combination of Alb-PRF with nanostructured carbonated hydroxyapatite microspheres (Alb-ncHA-PRF), and how this association affects the release capacity of growth factors and immunomodulatory molecules, and its impact on the behavior of MG63 human osteoblast-like cells. Alb-PRF membranes were prepared and associated with nanocarboapatite (ncHA) microspheres during polymerization. MG63 cells were exposed to eluates of both membranes to assess cell viability, proliferation, mineralization, and alkaline phosphatase (ALP) activity. The ultrastructural analysis has shown that the spheres were shattered, and fragments were incorporated into both the fibrin mesh and the albumin gel of Alb-PRF. Alb-ncHA-PRF presented a reduced release of growth factors and cytokines when compared to Alb-PRF (p < 0.05). Alb-ncHA-PRF was able to stimulate osteoblast proliferation and ALP activity at lower levels than those observed by Alb-PRF and was unable to positively affect in vitro mineralization by MG63 cells. These findings indicate that the addition of ncHA spheres reduces the biological activity of Alb-PRF, impairing its initial effects on osteoblast behavior.

Appraising and comparing the role of autogenous periosteal graft as a barrier membrane in the treatment of intrabony defects in chronic periodontitis cases: A systematic review and meta-analysis

Periodontal regeneration refers to procedures aimed at restitution of lost supporting tissue around the periodontally compromised tooth. Regenerative procedures very often include the use of barrier materials to encourage the growth of key surrounding tissues. The current study aimed to evaluate the effectiveness of autogenous periosteal graft as a barrier membrane for the treatment of intrabony defects in chronic periodontitis patients. A total of four data bases MEDLINE (by PubMed), Cochrane database, EBSCO, and Google Scholar were explored to identify the studies in English up to December 2022. An additional hand search of relevant journals was also done. A team of three independent reviewers screened the retrieved articles using the inclusion criteria. Randomized control trials (RCTs) evaluating the effectiveness of autogenous periosteal grafts in the treatment of intrabony defects in chronic periodontitis cases were included in the study. A total of six relevant articles were recognized for data procurement. A total of 117 patients with 68 sites with an age range between 18 years and 55 years were selected. Outcome variables examined were pocket depth (PD), clinical attachment level (CAL), radiographic bone defect fill (BDF), gingival recession (GR), plaque index (PI), gingival index (GI) and bleeding on probing (BOP). Data were analyzed using Revman 5.3 software. The mean differences and 95% confidence interval were used to illustrate the estimate of effect size. There is an equal effect in both groups for the PI, GI, and BOP reduction. For PD reduction, the result was in the favor of periosteal graft with open flap debridement (OFD) group. For CAL gain, radiographic BDF and GR, results also favored the periosteal graft, but no statistically significant difference was found amongst the groups. Within the limitation of the study, it seems that the autogenous periosteal graft can be used successfully along with OFD to treat intrabony defects in chronic periodontitis patients.

Bone regeneration property of tooth-derived bone substitute prepared chairside for periodontal bone defects: an experimental study

BACKGROUND

Periodontitis often leads to progressive destruction and loss of alveolar bone, the reconstruction of which remains difficult in periodontal therapy. As a novel bone graft material, tooth-derived bone substitute (TDBS) processed from extracted teeth has been previously reported about its osteoconductivity and promising results in bone regeneration. This study was to investigate the biological effects and bone regeneration properties of TDBS in vitro and in vivo using rat periodontal bone defect model.

METHODS

Three groups of materials were used in the experiments: TDBS, TDBS treated with ethylene diamine tetraacetic acid (EDTA) (TDBS-E), and allogeneic bone materials. Calcium (Ca) and phosphate (P) ion dissolutions were quantified by spectrophotometer for seven days. The releases of bone morphogenetic protein-2 (BMP-2) and transforming growth factor-β1 (TGF-β1) were identified by enzyme-linked immunosorbent assay (ELISA). Human osteoblast proliferation, migration, and differentiation were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell counting, alkaline phosphatase activity (ALP), and alizarin red staining (ARS), respectively. Furthermore, the osteogenic effects of TDBS on periodontal furcation bone defects were evaluated at eight weeks postoperatively using micro-computed tomography (Micro-CT) and histological analysis.

RESULTS

The dissolution of both Ca and P ions in TDBS increased over time. The BMP-2 released from TDBS was significantly higher than that from TDBS-E and allografts, while the TGF-β1 release from TDBS and TDBS-E groups was higher than that in the allografts. The TDBS-E group could induce the highest level of osteoblast proliferation compared to other groups. Cell migration with allografts co-culture was significantly induced compared to the blank control. However, all groups demonstrated similar positive effects on osteoblast differentiation. Furthermore, in the periodontal model, all materials could effectively enhance bone regeneration in the furcation defect.

CONCLUSIONS

The TDBS prepared chairside as an autogenous bone graft, demonstrating osteoinductivity, which enhances the osteogenic biological characteristics. Therefore, TDBS is suggested as an economical and biocompatible material for periodontal bone regeneration.

New Insights in Hydrogels for Periodontal Regeneration

Periodontitis is a destructive inflammatory disease characterized by microbial infection that damages the tissues supporting the tooth (alveolar bone, gingiva, periodontal ligament, and cementum), ultimately resulting in the loss of teeth. The ultimate goal of periodontal therapy is to achieve the regeneration of all of the periodontal tissues. Thus, tissue engineering approaches have been evolving from simple membranes or grafts to more complex constructs. Hydrogels are highly hydrophilic polymeric networks with the ability to simulate the natural microenvironment of cells. In particular, hydrogels offer several advantages when compared to other forms of scaffolds, such as tissue mimicry and sustained drug delivery. Moreover, hydrogels can maintain a moist environment similar to the oral cavity. Hydrogels allow for precise placement and retention of regenerative materials at the defect site, minimizing the potential for off-target effects and ensuring that the treatment is focused on the specific defect site. As a mechanism of action, the sustained release of drugs presented by hydrogels allows for control of the disease by reducing the inflammation and attracting host cells to the defect site. Several therapeutic agents, such as antibiotics, anti-inflammatory and osteogenic drugs, have been loaded into hydrogels, presenting effective benefits in periodontal health and allowing for sustained drug release. This review discusses the causes and consequences of periodontal disease, as well as the advantages and limitations of current treatments applied in clinics. The main components of hydrogels for periodontal regeneration are discussed focusing on their different characteristics, outcomes, and strategies for drug delivery. Novel methods for the fabrication of hydrogels are highlighted, and clinical studies regarding the periodontal applications of hydrogels are reviewed. Finally, limitations in current research are discussed, and potential future directions are proposed.

Histomorphometric evaluation, SEM, and synchrotron analysis of the biological response of biodegradable and ceramic hydroxyapatite-based grafts: from the synthesis to the bed application

This study aimed to analyze the physicochemical and histological properties of nanostructured hydroxyapatite and alginate composites produced at different temperatures with and without sintering and implanted in rabbit tibiae. Hydroxyapatite-alginate (HA) microspheres (425-600 µm) produced at 90 and 5 °C without (HA90 and HA5) or with sintering at 1000 °C (HA90S and HA5S) were characterized and applied to evaluate thein vitrodegradation; also were implanted in bone defects on rabbit's tibiae (n= 12). The animals were randomly divided into five groups (blood clot, HA90S, HA5S, HA90, and HA5) and euthanized after 7 and 28 d. X-ray diffraction and Fourier-transform infrared analysis of the non-sintered biomaterials showed a lower crystallinity than sintered materials, being more degradablein vitroandin vivo. However, the sinterization of HA5 led to the apatite phase's decomposition into tricalcium phosphate. Histomorphometric analysis showed the highest (p< 0.01) bone density in the blood clot group, similar bone levels among HA90S, HA90, and HA5, and significantly less bone in the HA5S. HA90 and HA5 groups presented higher degradation and homogeneous distribution of the new bone formation onto the surface of biomaterial fragments, compared to HA90S, presenting bone only around intact microspheres (p< 0.01). The elemental distribution (scanning electron microscope and energy dispersive spectroscopy andμXRF-SR analysis) of Ca, P, and Zn in the newly formed bone is similar to the cortical bone, indicating bone maturity at 28 d. The synthesized biomaterials are biocompatible and osteoconductive. The heat treatment directly influenced the material's behavior, where non-sintered HA90 and HA5 showed higher degradation, allowing a better distribution of the new bone onto the surface of the biomaterial fragments compared to HA90S presenting the same level of new bone, but only on the surface of the intact microspheres, potentially reducing the bone-biomaterial interface.

Advancing Dentistry through Bioprinting: Personalization of Oral Tissues

Despite significant advancements in dental tissue restoration and the use of prostheses for addressing tooth loss, the prevailing clinical approaches remain somewhat inadequate for replicating native dental tissue characteristics. The emergence of three-dimensional (3D) bioprinting offers a promising innovation within the fields of regenerative medicine and tissue engineering. This technology offers notable precision and efficiency, thereby introducing a fresh avenue for tissue regeneration. Unlike the traditional framework encompassing scaffolds, cells, and signaling factors, 3D bioprinting constitutes a contemporary addition to the arsenal of tissue engineering tools. The ongoing shift from conventional dentistry to a more personalized paradigm, principally under the guidance of bioprinting, is poised to exert a significant influence in the foreseeable future. This systematic review undertakes the task of aggregating and analyzing insights related to the application of bioprinting in the context of regenerative dentistry. Adhering to PRISMA guidelines, an exhaustive literature survey spanning the years 2019 to 2023 was performed across prominent databases including PubMed, Scopus, Google Scholar, and ScienceDirect. The landscape of regenerative dentistry has ushered in novel prospects for dentoalveolar treatments and personalized interventions. This review expounds on contemporary accomplishments and avenues for the regeneration of pulp-dentin, bone, periodontal tissues, and gingival tissues. The progressive strides achieved in the realm of bioprinting hold the potential to not only enhance the quality of life but also to catalyze transformative shifts within the domains of medical and dental practices.

Use of Injectable Platelet-Rich Fibrin Accompanied by Bone Graft in Socket Endurance: A Radiographic and Histological Study

Background Ridge preservation became a crucial dental health issue and strategy to keep away from ridge defacement after post-tooth loss. The recent scientific evolution of platelet-rich fibrin (PRF) comprises a parenteral formulation of PRF. The combined allograft for socket preservation gives benefits. In this study, bone allografts, demineralized freeze-dried bone allografts (DFDBA) and freeze-dried bone allografts (FDBA) are used in a 30:70 ratio alone or in combination with injectable PRF (I-PRF) for socket preservation. Methods This study is a radiographic and histological examination conducted on 60 participants aged between 19-65 years. Participating patients agreed voluntarily that they would not bear any fixed prosthesis for the next nine months and plan for implanted teeth placement, including multi-rooted mandibular molars denticles. Both groups received atraumatic extraction; then, the socket was preserved with bone allograft alone in the control group and bone allograft mixed with I-PRF, forming sticky bone, in the experimental group. Clinical, radiological, and histological assessments were taken at the inception stage, three months, six months, and nine months. A multivariate regression model and a generalized estimating equation (GEE) model were used to analyse the effects of these changes on outcomes. Results In all the parameters, the test group indicated a good amount of bone growth with increasing intervals of time for bone height radiographically with statistically significant difference present (p<0.05) and histologically after nine months when socket site grafted with bone graft in combination with I-PRF. Conclusion This study's results demonstrated that I-PRF possesses the potential to regenerate and heal in the tooth-extracted socket. This study further recommends the implementation of I-PRF in safeguarding and conserving the raised rim of the tooth. Future research should take place on the osteogenic capability of I-PRF in more comprehensive ridge accession surgical procedures and additional expanding and improving capacities in periodontal reconstruction.

Clinical and Radiographic Evaluation of Autologous Platelet-Rich Fibrin With or Without Demineralized Bone Matrix in the Treatment of Grade II Furcation Defects

Introduction This study aims to differentiate the employment of demineralized bone matrix (DMBM; Osseograft, Advanced Biotech Products (P) Ltd, Chennai, India) and platelet-rich fibrin (PRF) alone to a composite graft consisting of both materials in the surgical actions toward the anomalies of the human periodontal furcation imperfection. Methods In a split-mouth study, 30 patients with mandibular molars affected by the furcation were allocated without conscious choice to test (PRF + DMBM, n = 30) or control (PRF, n = 30) categories. At the starting point, three months after surgery, and six months later, the following modifiable factors were evaluated: probing pocket depth (PPD), full-mouth plaque scores, full-mouth gingival scores, radiographic defect depth, relative vertical clinical attachment level (RVCAL), and relative horizontal clinical attachment level (RHCAL). Results Results at three and six months demonstrated substantial differences between baseline values for both treatment methods in clinical and X-ray imaging appraisal. Nonetheless, the PRF/DMBM group manifests statistically significantly soaring changes observed in comparison to the PRF group. Overall, the probing depth (PD) in the test site was significantly lower than that in the control site, showing a reduction of 68% (95% CI=41%, 95%, p<0.001). Conclusion Clinical indications significantly improved with PRF and DMBM combined instead of PRF alone. On radiographs, the test group also showed higher bone fill.

Effects of combined application of fibroblast growth factor (FGF)-2 and carbonate apatite for tissue regeneration in a beagle dog model of one-wall periodontal defect

Introduction

There has been an increasing desire for the development of predictive periodontal regenerative therapy for severe periodontitis. In this study, we investigated the effect of the combined use of fibroblast growth factor-2 (FGF-2), a drug for periodontal regeneration approved in Japan, and carbonated apatite (CO₃Ap), bioresorbable and osteoconductive scaffold, on periodontal regeneration in beagle dog model of one-wall periodontal defect (severe intraosseous defect) for 24 weeks in comparison with CO₃Ap or vehicle alone.

Methods

One-wall periodontal defects were created (mesiodistal width × depth: 4 × 4 mm) on the mesial portion of the mandibular first molar (M1) of beagle dogs on both side. Mixture of FGF-2 and CO₃Ap, vehicle and CO₃Ap, or vehicle alone were administered to the defects and designated as groups FGF-2+CO₃Ap, CO₃Ap, and control, respectively. To assess the periodontal regeneration, radiographic analysis over time for 24 weeks, and micro computed tomography (μCT) and histological evaluation at 6 and 24 weeks were performed.

Results

For the regenerated tissue in the defect site, the mineral content of the FGF-2+CO₃Ap group was higher than that of the CO₃Ap group in the radiographic analysis at 6-24 weeks. In the context of new bone formation and replacement, the FGF-2+CO₃Ap group exhibited significantly greater new bone volume and smaller CO₃Ap volume than the CO₃Ap group in the μCT analysis at 6 and 24 weeks. Furthermore, the density of the new bone in the FGF-2+CO₃Ap group at 24 weeks was similar to those in the control and CO₃Ap groups. Histological evaluation revealed that the length of the new periodontal ligament and cementum in the FGF-2+CO₃Ap group was greater than that in the CO₃Ap group at 6 weeks. We also examined the effect of the combined use of the FGF-2 and CO₃Ap on the existing bone adjacent to the defect and demonstrated that the existing bone height and volume in the FGF-2+CO₃Ap group remained significantly greater than those in the CO₃Ap group.

Conclusion

This study demonstrated that the combination of FGF-2 and CO₃Ap was effective not only in enhancing new bone formation and replacing scaffold but also in maintaining the existing bone adjacent to the defect site in a beagle dog model of one-wall periodontal defect. Additionally, new periodontal tissues induced by FGF-2 and CO₃Ap may follow a maturation process similar to that formed by spontaneous healing. This suggests that the combined use of FGF-2 and CO₃Ap would promote periodontal regeneration in severe bony defects of periodontitis patient.

Chitosan: A Potential Biopolymer in Drug Delivery and Biomedical Applications

Chitosan, a biocompatible and biodegradable polysaccharide derived from chitin, has surfaced as a material of promise for drug delivery and biomedical applications. Different chitin and chitosan extraction techniques can produce materials with unique properties, which can be further modified to enhance their bioactivities. Chitosan-based drug delivery systems have been developed for various routes of administration, including oral, ophthalmic, transdermal, nasal, and vaginal, allowing for targeted and sustained release of drugs. Additionally, chitosan has been used in numerous biomedical applications, such as bone regeneration, cartilage tissue regeneration, cardiac tissue regeneration, corneal regeneration, periodontal tissue regeneration, and wound healing. Moreover, chitosan has also been utilized in gene delivery, bioimaging, vaccination, and cosmeceutical applications. Modified chitosan derivatives have been developed to improve their biocompatibility and enhance their properties, resulting in innovative materials with promising potentials in various biomedical applications. This article summarizes the recent findings on chitosan and its application in drug delivery and biomedical science.

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.

Interaction of Ceramic Implant Materials with Immune System

The immuno-compatibility of implant materials is a key issue for both initial and long-term implant integration. Ceramic implants have several advantages that make them highly promising for long-term medical solutions. These beneficial characteristics include such things as the material availability, possibility to manufacture various shapes and surface structures, osteo-inductivity and osteo-conductivity, low level of corrosion and general biocompatibility. The immuno-compatibility of an implant essentially depends on the interaction with local resident immune cells and, first of all, macrophages. However, in the case of ceramics, these interactions are insufficiently understood and require intensive experimental examinations. Our review summarizes the state of the art in variants of ceramic implants: mechanical properties, different chemical modifications of the basic material, surface structures and modifications, implant shapes and porosity. We collected the available information about the interaction of ceramics with the immune system and highlighted the studies that reported ceramic-specific local or systemic effects on the immune system. We disclosed the gaps in knowledge and outlined the perspectives for the identification to ceramic-specific interactions with the immune system using advanced quantitative technologies. We discussed the approaches for ceramic implant modification and pointed out the need for data integration using mathematic modelling of the multiple ceramic implant characteristics and their contribution for long-term implant bio- and immuno-compatibility.

Periodontal bone regeneration with a degradable thermoplastic HA/PLCL bone graft

Strategic bone grafts are required to regenerate periodontal bone defects owing to limited self-healing. Current bioceramic particle or deproteinized bovine bone (DBB) products are not able to ideally meet clinical requirements, such as insufficient operability and slow degradation rates. Herein, a strong-interacted bone graft was designed and synthesized by modifying hydroxyapatite (HA) with a lactide-caprolactone copolymer (PLCL) to improve component homogeneity and mechanical properties. The physical-chemical analysis indicated that HA particles were homogenously distributed in HA/PLCL bone grafts, possessed outstanding thermoplasticity, and facilitated clinic operability and initial mechanical support. The in vitro study suggested that HA/PLCL bone graft degraded in a spatiotemporal model. Micropores were formed on the non-porous surface at the beginning, and interconnected porous structures were gradually generated. Furthermore, HA/PLCL bone grafts exhibited excellent biocompatibility and osteogenic ability as revealed in vitro cell culture and in vivo animal experiments. When applied to rat periodontal bone defects, the HA/PLCL bone graft showed a non-inferior bone regeneration compared to the commercial DBB. This study proposes a potential bone graft for periodontal bone repair with thermoplastic, spatiotemporal degraded, and osteogenic characteristics.

Periodontal Therapy Using Bioactive Glasses: A Review

This paper reviews the use of bioactive glasses as materials for periodontal repair. Periodontal disease causes bone loss, resulting in tooth loosening and eventual tooth loss. However, it can be reversed using bioactive glass, typically the original 45S5 formulation (Bioglass®) at the defect site. This is done either by plcing bioactive glass granules or a bioactive glass putty at the defect. This stimulates bone repair and causes the defect to disappear. Another use of bioactive glass in periodontics is to repair so-called furcation defects, i.e., bone loss due to infection at the intersection of the roots in multi-rooted teeth. This treatment also gives good clinical outcomes. Finally, bioactive glass has been used to improve outcomes with metallic implants. This involves either placing bioactive glass granules into the defect prior to inserting the metal implant, or coating the implant with bioactive glass to improve the likelihood of osseointegration. This needs the glass to be formulated so that it does not crack or debond from the metal. This approach has been very successful, and bioactive glass coatings perform better than those made from hydroxyapatite.

Challenges and tissue engineering strategies of periodontal guided tissue regeneration

Periodontitis is a chronic infectious oral disease with a high prevalence rate in the world, and is a major cause of tooth loss. Nowadays, people have realized that the local microenvironment that includes proteins, cytokines, and extracellular matrix has a key influence on the functions of host immune cells and periodontal ligament stem cells during a chronic infectious disease such as periodontitis. The above pathological process of periodontitis will lead to a defect of periodontal tissues. Through the application of biomaterials, biological agents, and stem cells therapy, guided tissue regeneration (GTR) makes it possible to reconstruct healthy periodontal ligament tissue after local inflammation control. To date, substantial advances have been made in periodontal guided tissue regeneration. However, the process of periodontal remodeling experiences complex microenvironment changes, and currently periodontium regeneration still remains to be a challenging feat. In this review, we summarized the main challenges in each stage of periodontal regeneration, and try to put forward appropriate biomaterial treatment mechanisms or potential tissue engineering strategies that provide a theoretical basis for periodontal tissue engineering regeneration research.

A novel amnion-chorion allograft membrane combined with a coronally advanced flap: a minimally invasive surgical therapy to regenerate interdental papillary soft tissue recession - a six-month postoperative image analysis-based clinical trial

Objectives

Loss of the interdental papilla is multi-factorial and creates a multitude of problems. Autogenous connective tissue/biomaterial-based regeneration has been attempted for decades to reconstitute the black space created due to the loss of papilla. The aim of this present study was to regenerate papillary recession defects using an amnion-chorion membrane (ACM) allograft and to evaluate the clinical outcome up to six months postoperatively.

Materials and Methods

Twenty patients with 25 Nordland and Tarnow’s Class I/II interdental papillary recession defects were treated with ACM and coronal advancement of the gingivo-papillary unit via a semilunar incision on the labial aspect followed by a sulcular incision in the area of interest. A photographic image analysis was carried out using the GNU Image Manipulation software program from the baseline to three and six months postoperatively. The black triangle height (BTH) and the black triangle width (BTW) were calculated using the pixel size and were then converted into millimeters. The mean and standard deviation values were determined at baseline and then again at three and six months postoperatively. The probability values (P˂0.05 and P≤0.01) were considered statistically significant and highly significant, respectively. An analysis of variance and post hoc Bonferroni test were carried out to compare the mean values.

Results

Our evaluation of the BTH and BTW showed a statistically and highly significant difference from the baseline until both three and six months postoperatively (P=0.01). A post hoc Bonferroni test disclosed a statistically significant variance from the baseline until three and six months postoperatively (P˂0.05) and a non-significant difference from three to six months after the procedure (P≥0.05).

Conclusion

An ACM allograft in conjunction with a coronally advanced flap could be a suitable minimally invasive alternative for papillary regeneration.

Composite Fiber Spun Mat Synthesis and In Vitro Biocompatibility for Guide Tissue Engineering

Composite scaffolds are commonly used strategies and materials employed to achieve similar analogs of bone tissue. This study aims to fabricate 10% wt polylactic acid (PLA) composite fiber scaffolds by the air-jet spinning technique (AJS) doped with 0.5 or 0.1 g of zirconium oxide nanoparticles (ZrO₂) for guide bone tissue engineering. ZrO₂ nanoparticles were obtained by the hydrothermal method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). SEM and fourier-transform infrared spectroscopy (FTIR) analyzed the synthesized PLA/ZrO₂ fiber scaffolds. The in vitro biocompatibility and bioactivity of the PLA/ZrO₂ were studied using human fetal osteoblast cells. Our results showed that the hydrothermal technique allowed ZrO₂ nanoparticles to be obtained. SEM analysis showed that PLA/ZrO₂ composite has a fiber diameter of 395 nm, and the FITR spectra confirmed that the scaffolds’ chemical characteristics are not affected by the synthesized technique. In vitro studies demonstrated that PLA/ZrO₂ scaffolds increased cell adhesion, cellular proliferation, and biomineralization of osteoblasts. In conclusion, the PLA/ZrO₂ scaffolds are bioactive, improve osteoblasts behavior, and can be used in tissue bone engineering applications.

The Effect of Diabetes Mellitus on IGF Axis and Stem Cell Mediated Regeneration of the Periodontium

Periodontitis and diabetes mellitus (DM) are two of the most common and challenging health problems worldwide and they affect each other mutually and adversely. Current periodontal therapies have unpredictable outcome in diabetic patients. Periodontal tissue engineering is a challenging but promising approach that aims at restoring periodontal tissues using one or all of the following: stem cells, signalling molecules and scaffolds. Mesenchymal stem cells (MSCs) and insulin-like growth factor (IGF) represent ideal examples of stem cells and signalling molecules. This review outlines the most recent updates in characterizing MSCs isolated from diabetics to fully understand why diabetics are more prone to periodontitis that theoretically reflect the impaired regenerative capabilities of their native stem cells. This characterisation is of utmost importance to enhance autologous stem cells based tissue regeneration in diabetic patients using both MSCs and members of IGF axis.

The Evolution of Surgical Techniques and Biomaterials for Periodontal Regeneration

The understanding of biological concepts in wound healing together with the evolution in biomaterials applied in periodontal regeneration allowed for improved, minimally invasive surgical techniques with a wider range of application and adapted to achieve multiple goals at the same time. Regenerating attachment was never the sole end point, but maintaining the patient's own natural dentition in health and esthetics is becoming a feasible goal even in cases considered challenging just a few years ago. In this article we report on the evolution of techniques and biomaterials and their application in esthetic and challenging cases.

A Review of the Effects of Collagen Treatment in Clinical Studies

Collagen, an abundant extracellular matrix protein, has been found to have a lot of pharmaceuticals, medicine, food, and cosmetics applications. Increased knowledge of collagen sources, extraction techniques, structure, and properties in the last decades has helped develop more collagen-based products and tissue engineering biomaterials. Collagen products have been playing an important role in benefiting the health of the human body, especially for aging people. In this paper, the effects of collagen treatment in different clinical studies including skin regeneration, bone defects, sarcopenia, wound healing, dental therapy, gastroesophageal reflux, osteoarthritis, and rheumatoid arthritis have been reviewed. The collagen treatments were significant in these clinical studies. In addition, the associations between these diseases were discussed. The comorbidity of these diseases might be closely related to collagen deficiency, and collagen treatment might be a good choice when a patient has more than one of these diseases, including the coronavirus disease 2019 (COVID-19). It concludes that collagen-based medication is useful in treating comorbid diseases and preventing complications.

Synergistic Effect of Biphasic Calcium Phosphate and Platelet-Rich Fibrin Attenuate Markers for Inflammation and Osteoclast Differentiation by Suppressing NF-κB/MAPK Signaling Pathway in Chronic Periodontitis

Background: Periodontitis is characterized by excessive osteoclastic activity, which is closely associated with inflammation. It is well established that MAPK/NF-kB axis is a key signaling pathway engaged in osteoclast differentiation. It is stated that that biphasic calcium phosphate (BCP) and platelet-rich fibrin (PRF) have significant antiostoeclastogenic effects in chronic periodontitis. Objective: We aimed to elucidate the synergetic effect of PRF/BCP involvement of the nuclear factor kappa–light–chain–enhancer of activated B cells (NF-kB) and the mitogen-activated protein kinase (MAPK) signaling pathway in osteoclast differentiation in chronic periodontitis. Methods: We induced osteoclast differentiation in vitro using peripheral blood mononuclear cells (PBMCs) derived from patients with chronic periodontitis. We assessed osteoclast generation by tartrate-resistant acid phosphatase (TRAP) activity, proinflammatory cytokines were investigated by ELISA and NF-κB, and IKB by immunoblot, respectively. MAPK proteins and osteoclast transcription factors were studied by Western blot analysis and osteoclast transcriptional genes were assessed by RT-PCR. Results: The results showed that the potent inhibitory effect of PRF/BCP on osteoclastogenesis was evidenced by decreased TRAP activity and the expression of transcription factors, NFATc1, c-Fos, and the osteoclast marker genes, TRAP, MMP-9, and cathepsin-K were found to be reduced. Further, the protective effect of PRF/BCP on inflammation-mediated osteoclastogenesis in chronic periodontitis was shown by decreased levels of proinflammatory cytokines, NF-kB, IKB, and MAPK proteins. Conclusions: PRF/BCP may promote a synergetic combination that could be used as a strong inhibitor of inflammation-induced osteoclastogenesis in chronic periodontitis.

Recombinant factors for periodontal intrabony defects: A systematic review and network meta-analysis of preclinical studies

The use of bioactive agents combined with osteoconductive scaffolds for the regeneration of periodontal intrabony defects has been the subject of intensive research in the past 20 years. Most studies reported that such agents, used in different concentrations, doses and combined with various scaffolds, might promote periodontal tissue regeneration, but evidence for the most effective combination of such agents is lacking. The objective of this study 13 was to rank the different combinations of recombinant human-derived growth and differentiation factors with/without scaffold biomaterial in the treatment of periodontal intrabony defects, through network meta-analysis of pre-clinical studies. The systematic review and network meta-analysis protocol was registered on the PROSPERO Systematic Review database with reference number: CRD42021213673. Relevant published articles were obtained after searching five electronic databases. A specific search strategy was followed by using keywords related to intrabony defects, regenerative materials, scaffolds and recombinant factors, and animal studies. All pre-clinical studies used for periodontal regeneration were included. The primary outcomes were: regeneration of junctional epithelium (mm), new cementum, connective tissue attachment, percentage of new bone formation (%), bone area (mm² ), bone volume density (g/cm³ ) and bone height (mm) data was extracted. The analysis was carried out using network meta-analysis methods, that is illustrating network plots, contribution plots, predictive and confidence interval plot, surface under the cumulative ranking (SUCRA), multidimensional scale ranking and net funnel plots using STATA IC statistical software. An SYRCLE's tool for assessing risk of bias was used for reporting risk of bias among individual studies. A total of N = 24 for qualitative and N = 21 studies for quantitative analysis published till 2020 were included. The cumulative total number of animals included in the control and test groups were N = 162 and N = 339, respectively. The duration of the study was between 3 and 102 weeks rhBMP-2 ranked higher in SUCRA as the agent associated with the best performance for bone volume density. rhGDF-5/TCP ranked best in the bone area (mm2), rhPDGF-BB/Equine ranked best in bone height (mm), rhBMP-2 ranked best in the percentage of new bone fill, rhBMP-2/ACS ranked best in new cementum formation, and rhGDF-5/b- TCP/PLGA ranked best in connective tissue attachment and junctional epithelium. There were no adverse effects identified in the literature that could affect the different outcomes for regeneration in intrabony defects. Various recombinant factors are effective in promoting the regeneration of both soft and hard tissue supporting structures of the periodontium. However, when considering different outcomes, different agents, associated or not with biomaterials, ranked best. Keeping into account the limited transferability of results from animal studies to the clinical setting, the choice of the most appropriate formulation of bioactive agents may depend on clinical needs and purpose.

Nature-Inspired Unconventional Approaches to Develop 3D Bioceramic Scaffolds with Enhanced Regenerative Ability

Material science is a relevant discipline in support of regenerative medicine. Indeed, tissue regeneration requires the use of scaffolds able to guide and sustain the natural cell metabolism towards tissue regrowth. This need is particularly important in musculoskeletal regeneration, such as in the case of diseased bone or osteocartilaginous regions for which calcium phosphate-based scaffolds are considered as the golden solution. However, various technological barriers related to conventional ceramic processing have thus far hampered the achievement of biomimetic and bioactive scaffolds as effective solutions for still unmet clinical needs in orthopaedics. Driven by such highly impacting socioeconomic needs, new nature-inspired approaches promise to make a technological leap forward in the development of advanced biomaterials. The present review illustrates ion-doped apatites as biomimetic materials whose bioactivity resides in their unstable chemical composition and nanocrystallinity, both of which are, however, destroyed by the classical sintering treatment. In the following, recent nature-inspired methods preventing the use of high-temperature treatments, based on (i) chemically hardening bioceramics, (ii) biomineralisation process, and (iii) biomorphic transformations, are illustrated. These methods can generate products with advanced biofunctional properties, particularly biomorphic transformations represent an emerging approach that could pave the way to a technological leap forward in medicine and also in various other application fields.

The optimization of pepsin processing time to balance the mechanical and biological properties of xenogeneic bone

Xenogeneic bone showed great prospects to treat large bone defects due to its bionic composition and structure, but the immunogenicity limited its wide applications. Previously, we developed a pepsin treating method to eliminate the immunogenicity of xenogeneic bone. In this study, we further investigated the effect of pepsin processing time on the biological and mechanical properties. The results indicated that increased pepsin treating time impaired the mechanical properties of xenogeneic bone. And MC3T3-E1 cells showed enhanced adhesion ability, as well as increased production of alkaline phosphatase and calcium nodulus production on the xenogeneic bone processed by pepsin for 24 hr (P24), as compared with xenogeneic bone processed by pepsin for 30 hr (P30) and 36 hr (P36). In addition, we found no significant inflammatory responses after implanting different xenogeneic bone into the intermuscular site of rats. These results suggested that xenogeneic bone processed by pepsin for 24 hr may be a preferable choice when using the xenogeneic bone as biomaterials for further researches.

Bismuth subsalicylate incorporated in polycaprolactone-gelatin membranes by electrospinning to prevent bacterial colonization

Periodontitis is a chronic, multifactorial, inflammatory disease characterized by the progressive destruction of the periodontal tissues. Guided tissue regeneration (GTR), involving the use of barrier membranes, is one of the most successful clinical procedures for periodontal therapy. Nevertheless, rapid degradation of the membranes and membrane-related infections are considered two of the major reasons for GTR clinical failure. Recently, integration of non-antibiotic, antimicrobial materials to the membranes has emerged as a novel strategy to face the bacterial infection challenge, without increasing bacterial resistance. In this sense, bismuth subsalicylate (BSS) is a non-antibiotic, metal-based antimicrobial agent effective against different bacterial strains, that has been long safely used in medical treatments. Thus, the aim of the present work was to fabricate fibrillar, non-rapidly bioresorbable, antibacterial GTR membranes composed of polycaprolactone (PCL), gelatin (Gel), and BSS as the antibacterial agent. PCL-G-BSS membranes with three different BSS concentrations (2 wt./v%, 4 wt./v%, and 6 wt./v%) were developed by electrospinning and their morphology, composition, water wettability, mechanical properties, Bi release and degradation rate were characterized. The Cytotoxicity of the membranes was studiedin vitrousing human osteoblasts (hFOB) and gingival fibroblasts (HGF-1), and their antibacterial activity was tested againstAggregatibacter actinomycetemcomitans, Escherichia coli, Porphyromonas gingivalisandStaphylococcus aureus.The membranes obtained exhibited adequate mechanical properties for clinical application, and appropriate degradation rates for allowing periodontal defects regeneration. The hFOB and HGF-1 cells displayed adequate viability when in contact with the lixiviated products from the membranes, and, in general, displayed antibacterial activity against the four bacteria strains tested. Thus, the PCL-G-BSS membranes showed to be appropriate as potential barrier membranes for periodontal GTR treatments.

Biodegradable aniline-derived electroconductive film for the regulation of neural stem cell fate

Neural stem cells (NSCs) represent significant potential and promise in the treatment of neurodegenerative diseases and nerve injuries. An efficient methodology or platform that can help in specifically directing the stem cell fate is important and highly desirable for future clinical therapy. In this study, a biodegradable electrical conductive film composed of an oxidative polymerized carboxyl-capped aniline pentamer (CCAP) and ring-opening polymerized tetra poly(d,l-lactide) (4a-PLA) was designed with the addition of the dopant, namely chondroitin sulfate. This conductive film acts as a biological substrate for the exogenous/endogenous electric field transmission in tissue, resulting in the control of NSC fate, as well as improvement in neural tissue regeneration. The results show that CCAP is successfully synthesized and then conjugated onto 4a-PLA to form a network structure with electrical conductivity, cell adhesion capacity, and biodegradability. The neuronal differentiation of NSCs can be induced on 4a-PLAAP, and the neuronal maturation process can be facilitated by the manipulation of the electrical field. This biocompatible and electroactive material can serve as a platform to determine the cell fate of NSCs and be employed in neural regeneration. For future perspectives, its promising performance shows potential in applications, such as electrode-tissue integration interfaces, coatings on neuroprosthetics devices and neural probes, and smart drug delivery system in neurological systems.

Clinical and radiographic evaluation of demineralized freeze-dried bone allograft with concentrated growth factor versus concentrated growth factor alone in the treatment of intrabony defects

Background

Periodontal disease is one of the major causes of alveolar bone loss. There are various ways of regenerating the lost bone, i.e. guided tissue regeneration, bone grafts, and growth factors. In this purview, it becomes immensely important for a clinician to decide the best modality of treatment. In this study, we compared the effect of demineralized freeze-dried bone allograft (DFDBA) in combination with concentrated growth factors (CGF) verses CGF alone.

Methods

This double-blind, split-mouth study was conducted on ten patients with two comparable bilateral intrabony defects. Each pair of defects was randomly treated by DFDBA + CGF or CGF alone. Clinical parameters such as plaque index (PI), modified gingival index (MGI), pocket probing depth (PPD), and relative attachment level (RAL) were recorded at baseline, three months, and six months. In addition, radiograph with grids was also taken at baseline and six months. The paired t-test was used to compare the pre- and post-treatment values and the unpaired t-test was used to compare the test and control group.

Results

The PI score decreased significantly from baseline to six months. Similarly, the mean MGI score decreased significantly from baseline to six months. The intragroup comparison showed that there was a significant reduction in PPD in both the test and control group. However, the intergroup comparison showed that the reduced pocket depth was not significant. The intragroup radiographic comparison showed that there was the significant formation of bone in both the test and control group but inter-group showed that the formation of bone among both the group were non-significant.

Conclusion

Radiographic and clinical outcomes of this study concluded that post six months, both groups demonstrated significant improvement in clinical and radiographic parameters. However, the addition of DFDBA to CGFs did not give any additional benefits.

Advanced Biomaterials and Techniques for Oral Tissue Engineering and Regeneration-A Review

The reconstruction or repair of oral and maxillofacial functionalities and aesthetics is a priority for patients affected by tooth loss, congenital defects, trauma deformities, or various dental diseases. Therefore, in dental medicine, tissue reconstruction represents a major interest in oral and maxillofacial surgery, periodontics, orthodontics, endodontics, and even daily clinical practice. The current clinical approaches involve a vast array of techniques ranging from the traditional use of tissue grafts to the most innovative regenerative procedures, such as tissue engineering. In recent decades, a wide range of both artificial and natural biomaterials and scaffolds, genes, stem cells isolated from the mouth area (dental follicle, deciduous teeth, periodontal ligament, dental pulp, salivary glands, and adipose tissue), and various growth factors have been tested in tissue engineering approaches in dentistry, with many being proven successful. However, to fully eliminate the problems of traditional bone and tissue reconstruction in dentistry, continuous research is needed. Based on a recent literature review, this paper creates a picture of current innovative strategies applying dental stem cells for tissue regeneration in different dental fields and maxillofacial surgery, and offers detailed information regarding the available scientific data and practical applications.

Interproximal attachment gain: The challenge of periodontal regeneration

The new classification of periodontal diseases recognizes the key role of the interdental clinical attachment for defining the periodontal status and the extent of disease severity. Regenerating interdental clinical attachment not only improves the prognosis of the tooth, but it also lessens the severity of the disease condition. This manuscript provides a state-of-the-art review on surgical reconstructive approaches for treating papillary deficiency associated with soft and hard tissue interproximal defects. Combination therapy of papilla preservation, connective tissue grafting, and coronally advanced flaps may result in regeneration of the intrabony defect coupled with root coverage. Future research highlighted here may have the potential, especially in combination approaches, to repair challenging interproximal soft and hard tissue deficiencies.

Weissella cibaria EIR/P2-derived exopolysaccharide: A novel alternative to conventional biomaterials targeting periodontal regeneration

Healing and regeneration of periodontium are considered as a complex physiological process. Therefore, treatments need to be addressed with highly effective components modulating the multiple pathways. In this study, exopolysaccharide (EPS) produced by Weissella cibaria EIR/P2, was partially purified from the culture supernatant and subjected to characterization within the aim of evaluating its potential for periodontal regeneration. High-Performance Liquid Chromatography analysis revealed a single-peak corresponding to the glucose which identified the EPS as dextran. Fourier transform-infrared spectra were also displayed characteristic peaks for polysaccharides. According to the results of gel permeation/size exclusion-chromatography, the molecular mass was determined to be 8 × 10⁶ Da. To clarify its anti-bacterial activity on Streptococcus mutans, effects on viability and biofilm formation was evaluated. At 50 mg/mL, dextran exhibited a bactericidal effect with 70% inhibition on biofilm formation. Besides, dose-dependent antioxidant effects were also detected. The efficacy of dextran in enhancing the viability of human periodontal ligament fibroblast cells (hPDLFCs) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide (MTT) assay, and an increase was observed in the viability of hPDLFCs. In conclusion, dextran derived from W. cibaria can be potentially used as a multi-functional bioactive polymer in the design of new therapeutic strategies to promote healing and regeneration of periodontium.

Current Insight of Collagen Biomatrix for Gingival Recession: An Evidence-Based Systematic Review

Collagen (Col) is a naturally available material and is widely used in the tissue engineering and medical field owing to its high biocompatibility and malleability. Promising results on the use of Col were observed in the periodontal application and many attempts have been carried out to inculcate Col for gingival recession (GR). Col is found to be an excellent provisional bioscaffold for the current treatment in GR. Therefore, the aim of this paper is to scrutinize an overview of the reported Col effect focusing on in vitro, in vivo, and clinical trials in GR application. A comprehensive literature search was performed using EBSCOhost, Science Direct, Springer Link, and Medline & Ovid databases to identify the potential articles on particular topics. The search query was accomplished based on the Boolean operators involving keywords such as (1) collagen OR scaffold OR hybrid scaffold OR biomaterial AND (2) gingiva recession OR tissue regeneration OR dental tissue OR healing mechanism OR gingiva. Only articles published from 2015 onwards were selected for further analysis. This review includes the physicochemical properties of Col scaffold and the outcome for GR. The comprehensive literature search retrieved a total of 3077 articles using the appropriate keywords. However, on the basis of the inclusion and exclusion criteria, only 15 articles were chosen for further review. The results from these articles indicated that Col promoted gingival tissue regeneration for GR healing. Therefore, this systematic review recapitulated that Col enhances regeneration of gingival tissue either through a slow or rapid process with no sign of cytotoxicity or adverse effect.