Periodontal and endodontic regeneration

The impact of bone grafting with/without barrier membrane placement on the outcome of apical surgery: A systematic review and meta-analysis

BACKGROUND

Regenerative techniques are increasingly being advocated in endodontic apical surgery (AS) to enhance the healing of periapical lesions. Various grafting and membrane materials are employed as adjuncts to modern AS.

OBJECTIVES

This systematic review aimed to answer the following PICO question: In patients with apical periodontitis (P) what is the impact of bone grafting with/without barrier membrane materials (I) compared with surgery without grafting materials (C) on the outcome of AS evaluated clinically and radiographically (O).

METHODS

A systematic search was conducted in four databases (Embase, Web of Science, PubMed and Cochrane Central Register of Controlled Trials) until 1 August 2023. Google Scholar was also manually searched. Studies with a prospective randomized design were included. Cochrane risk-of-bias (RoB) tool 2.0 assessed bias. Two independent reviewers performed the study selection, data extraction and appraisal of studies. Meta-analysis was performed using R3.5.1 software.

RESULTS

From the identified 2582 studies, eight randomized clinical trials were included for meta-analysis. Two studies had low RoB, while six had some concerns. Analysis revealed significantly better outcomes when surgery involved bone regeneration techniques than conventional surgery (OR = 2.18, 95% CI: 1.32-4.31, p = .004). Subgroup analyses on individual grafts (OR = 0.22, 95% CI: -0.99 to 1.44, p = .720) (OR = -0.09, 95% CI: -1.42 to 1.23, p = .885) and membranes (OR = -1.09, 95% CI: -2.94 to 0.76, p = .247) and their combinations (OR = 0.03, 95% CI: -1.50 to 1.55, p = .970) did not yield any significant results. The type of membrane used did not significantly impact the outcome (OR = -1.09, 95% CI: -2.94 to 0.76, p = .247) nor did altering the combination of graft/membrane.

DISCUSSION

This systematic review examined the effects of bone grafting with/without membrane placement on the outcome of AS. It highlights the potential advantages of regenerative techniques and the need for further research in this area.

CONCLUSIONS

Based on current evidence, bone grafting with/without barrier membrane placement significantly improves healing after AS. Subgroup analysis of resorbable membranes or grafting did not significantly influence the outcome. The combination of membrane and graft was also not significant. Future well-designed, randomized controlled trials in this area are essential before these materials can be recommended for routine use to enhance healing outcomes in AS.

REGISTRATION

PROSPERO (CRD42021255171).

Treatment of an Infrabony Defect of a Maxillary Canine Tooth Using Enamel Matrix Derivatives with Allogeneic Bone Augmentation in a Dog

A 5-year-old Miniature Dachshund was presented having an infrabony pocket on the palatal aspect of the right maxillary canine tooth. The bony defect had worsened despite previous closed root planing and administration of a perioceutic agent. A second surgery using an allogeneic cancellous bone augmentation with an enamel matrix derivative was performed in the infrabony defect following open root planing. Eight months after the periodontal surgery, the osseous defect showed healing by improved periodontal probing measurements and increased radiopacity using dental radiography and computed tomography.

Efficacy of mixture of injectable-platelet-rich fibrin and type-1 collagen particles on the closure of through-and-through periapical bone defects: A randomized controlled trial

AIM

To determine the efficacy of a combination of injectable-platelet-rich fibrin and type-1 collagen particles on the healing of through-and-through periapical bone defect and subsequent closure of bony window.

METHODOLOGY

The clinical trial was registered in ClinicalTrials.gov (NCT04391725). Thirty-eight individuals with radiographic evidence of periapical radiolucency in maxillary anterior teeth and confirmed loss of palatal cortical plates in cone beam computed tomographic imaging were randomly assigned to either the experimental group (n = 19) or the control group (n = 19). A mixture of i-PRF and collagen as a graft was applied to the defect in adjunct to periapical surgery in the experimental group. No guided bone regeneration procedures were used in the control group. The healing was evaluated using Molven's (2D) and modified PENN 3D (3D) criteria. Percentage reduction of the buccal and palatal bony window area, and complete closure of through-and-through periapical bony window (tunnel defect) were assessed using Radiant Diacom viewer software (Version 4.0.2). The reduction in the periapical lesion area and volume was measured using Corel DRAW and ITK Snap software.

RESULTS

Thirty-four participants (18 and 16 in the experimental and control groups respectively) reported for follow-up at 12 months. There was 96.9% and 97.96% reduction of buccal bony window area in the experimental and control groups respectively. Similarly, palatal window showed 99.03% and 100% reduction in the experimental and control groups respectively. No significant difference in both buccal and palatal window reduction was noticed between the groups. A total of 14 cases (seven in the experimental group and seven in the control group) showed complete closure of through-and-through bony window. No significant difference in clinical, 2D and 3D radiographic healing, percentage reduction in area and volume was observed between the experimental and control groups (p > .05). Neither the area nor the volume of lesion, and the size of buccal or palatal window had significant effect on healing of through-and-through defects.

CONCLUSION

Endodontic microsurgery results in high success rate in large periapical lesions with through-and-through communication with more than 80% reduction in volume of lesion and size of both buccal and palatal window after 1 year. A mixture of type-1 collagen particles and i-PRF, adjunct to periapical micro-surgery did not improve the healing in through-and-through periapical defects.

Management of Apico-marginal Defects With Endodontic Microsurgery and Guided Tissue Regeneration: A Report of Thirteen Cases

The loss of periodontal tissue support and vertical buccal bone loss in apico-marginal defects can often be mistaken for features indicative of vertical root fractures and this study reports thirteen cases with persistent symptomatic apical periodontitis, apico-marginal defects, and large periapical lesions that were managed with endodontic microsurgery in conjunction with bone grafts and barrier placements with a follow-up period of up to 9 years. At the recall sessions, all cases were asymptomatic with radiographical success with only 2 cases exhibiting residual apical radiolucency, but with evident reduction in the lesion size, indicative of healing. This study highlights the potential of utilizing endodontic microsurgery combined with guided tissue regeneration that proved effective in stimulating the regeneration of periodontal tissue in cases of apico-marginal defects that can lead to favourable long-term outcomes.

Application of advanced platelet-rich fibrin for through-and-through bony defect during endodontic surgery: Three case reports and review of the literature

BACKGROUND

The use of advanced platelet-rich fibrin (A-PRF) membranes for guided bone and tissue regeneration in through-and-through defects after endodontic surgery was explored in three cases.

CASE SUMMARY

Herein, three patients presented to the endodontic clinic suffering from apical periodontitis, associated with large bone resorption and related to previously endodontically treated teeth. Periapical surgery was indicated in these cases and the osteotomy site was covered by A-PRF membrane. Cone-beam computed tomography (CBCT) was used to assess the cases before and after the surgery.

CONCLUSION

Four months post-surgery, the recall CBCT scan showed complete obliteration of the osteotomy with newly formed bone. A-PRF membrane showed promising results and was an advantageous addition to surgical endodontic treatment.

Layered scaffolds in periodontal regeneration

Periodontitis is a common inflammatory disease in dentistry that may lead to tooth loss and aesthetic problems. Periodontal tissue has a sophisticated architecture including four sections of alveolar bone, cementum, gingiva, and periodontal ligament fiber; all these four can be damaged during periodontitis. Thus, for whole periodontal regeneration, it is important to form both hard and soft tissue structures simultaneously on the tooth root surface without forming junctional epithelium and ankylosis. This condition makes the treatment of the periodontium a challenging process. Various regenerative methods including Guided Bone/Tissue Regeneration (GBR/GTR) using various membranes have been developed. Although using such GBR/GTR membranes was successful for partial periodontal treatment, they cannot be used for the regeneration of complete periodontium. For this purpose, multilayered scaffolds are now being developed. Such scaffolds may include various biomaterials, stem cells, and growth factors in a multiphasic configuration in which each layer is designed to regenerate specific section of the periodontium. This article provides a comprehensive review of the multilayered scaffolds for periodontal regeneration based on natural or synthetic polymers, and their combinations with other biomaterials and bioactive molecules. After highlighting the challenges related to multilayered scaffolds preparation, features of suitable scaffolds for periodontal regeneration are discussed.

Personalized Medicine Based on the Pathogenesis and Risk Assessment of Endodontic-Periodontal Lesions

Endodontic-periodontal lesions (EPLs) are chronic inflammatory lesions in the mouth caused by multiple factors. Both periapical and marginal periodontitis are characterized by infection and inflammation around the affected teeth, suggesting that the theory of complex systems might describe the progression of EPL. The diagnosis and treatment of EPLs are complicated by variations of this condition and difficulties distinguishing EPLs from other diseases. Technological advances in diagnostic and treatment methods, including cone beam computed tomography, microscopy, mineral trioxide aggregates, and periodontal regenerative treatment, have improved outcomes, even in untreatable teeth. However, treating EPLs with iatrogenic problems and/or severe periodontitis remains challenging. Assessing the risk of each EPL based on the possible pathogenesis of each EPL is essential for determining individualized treatment and optimizing personalized medicine for individual patients.

Regulation of LL-37 in Bone and Periodontium Regeneration

The goal of regenerative therapy is to restore the structure and function of the lost tissues in the fields of medicine and dentistry. However, there are some challenges in regeneration therapy such as the delivery of oxygen and nutrition, and the risk of infection in conditions such as periodontitis, osteomyelitis, etc. Leucine leucine-37 (LL-37) is a 37-residue, amphipathic, and helical peptide found only in humans and is expressed throughout the body. It has been shown to induce neovascularization and vascular endothelial growth factor (VEGF) expression. LL-37 also stimulates the migration and differentiation of mesenchymal stem cells (MSCs). Recent studies have shown that LL-37 plays an important role in the innate defense system through the elimination of pathogenic microbes and the modulation of the host immune response. LL-37 also manifests other functions such as promoting wound healing, angiogenesis, cell differentiation, and modulating apoptosis. This review summarizes the current studies on the structure, expression, and function of LL-37 and highlights the contributions of LL-37 to oral cavity, periodontium, and bone regeneration.

Healing Assessment of Osseous Defects after Surgical Removal of Periapical Lesions in the Presence of Hydroxyapatite, Nanohydroxyapatite, and a Combination of Nanohydroxyapatite and Platelet-rich Fibrin: A Clinical Study

Abstract: Aim: to evaluate the bone healing in failed endodontically treated teeth after surgical removal of periapical lesions and placement of hydroxyapatite (HA), nanohydroxyapatite (nHA) and a combination of nanohydroxyapatite with platelet rich fibrin (PRF) periapically. Subjects and methods: the study was conducted on twenty-four patients having periapical radiolucency in single rooted teeth. The selected teeth were divided into three groups: Group A, Group B, and Group C; of 8 teeth each. All the teeth were retreated in two visits. In the first visit the old filling was removed using Protaper retreatment files (Dentsply Sirona®) then irrigation with sodium hypochlorite 2.5% was done. All canals were dried and filled with Di-antibiotic paste (metronidazole and ciprofloxacin). In the second visit the canals were obturated with Pro Taper gutta-percha points and root canal sealer (Adseal resin sealer) followed by surgical intervention in the same day. A periapical curettage along with apicoectomy were established. In all the groups, root end cavity was prepared and filled with MTA (ProRoot MTA; DENTSPLY Tulsa Dental Specialties). In Group A, hydroxyapatite powder was packed in the curetted periapical defect. In Group B, nanohydroxyapatite powder was packed in the curetted periapical defect. In Group C, nanohydroxyapatite with PRF were mixed and packed in the curetted periapical defect. In all groups, patients recall visits were scheduled at 1, 3, and 6 months’ time intervals for clinical and radiological evaluation. Results: after one month; there was a statistically significant difference between the median percentage changes in lesions size in the three groups. Pair-wise comparisons between groups revealed that there was no statistically significant difference between group B (nHA) and group C (PRF and nHA) groups. Both showed statistically significantly higher median percentage reduction in lesions size than group A (HA group). After three as well as six months; there was no statistically significant difference between the median percentage decreases in lesions size in the three groups. Conclusion: It was concluded that nHA combination with PRF produced faster periapical healing (bone regeneration) in the first three months than nHA alone. However, HA produce periapical healing (bone regeneration) after six months.

Inhibition of c-Jun N-terminal kinase signaling promotes osteoblastic differentiation of periodontal ligament stem cells and induces regeneration of periodontal tissues

OBJECTIVES

Few clinical treatments to regenerate periodontal tissue lost due to severe endodontic and periodontal disease have yet been developed. Therefore, the development of new treatment methods for the regeneration of periodontal tissue is expected. The purpose of this study was to investigate the effects of a c-Jun N-terminal kinase (JNK) inhibitor, SP600125, on the osteoblastic differentiation of periodontal ligament stem cells (PDLSCs) in vitro, and the function of SP600125 on the regeneration of alveolar bone in vivo.

DESIGN

Alizarin red S staining, quantitative RT-PCR, and western blotting analysis was performed to determine whether SP600125 affects osteoblastic differentiation of human PDLSCs (HPDLSCs) and bone-related intracellular signaling. The effect of SP600125 on the regeneration of alveolar bone was assessed by using a rat periodontal defect model. The healing of periodontal defects was evaluated using micro-CT scans and histological analysis.

RESULTS

SP600125 promoted the osteoblastic differentiation such as Alizarin red S-positive mineralized nodule formation and the expression of osteoblast-related genes in HPDLSCs under osteogenic conditions. In addition, this inhibitor upregulated the BMP2 expression and the phosphorylation of Smad1/5/8 in HPDLSCs under the same conditions. The inhibition of Smad1/5/8 signaling by LDN193189 suppressed the SP600125-induced osteoblastic differentiation of HPDLSCs. Furthermore, the application of SP600125 promoted the regeneration of not only alveolar bone but also PDL tissue in periodontal defects.

CONCLUSION

This study suggested that inhibition of JNK signaling promotes the osteoblastic differentiation of HPDLSCs through BMP2-Smad1/5/8 signaling, leading to the regeneration of periodontal tissues such as alveolar bone and PDL tissue.

Evaluation of Guided Bone Regeneration in Critical Defects Using Bovine and Porcine Collagen Membranes: Histomorphometric and Immunohistochemical Analyses

Guided bone regeneration (GBR) is a technique used to facilitate bone regeneration, which uses a biocompatible membrane acting as a physical barrier to prevent the adjacent connective tissue from invading the bone defect. The aim of this study was to evaluate and compare the effectiveness of bovine and porcine collagenous membranes as barriers to connective tissue invasion during the repair of critical bone defects in rat calvaria, using histological, histometric, and immunohistochemical analyses. For this study, 72 rats were divided into three groups: clot group (CG), bovine collagen group (BCG), and porcine collagen group (PCG). Analyses were performed on days 7, 15, 30, and 60. The histological results showed that the PCG exhibited bone neoformation starting from day 7, and after 30 days of repair, the surgical defect was completely filled in some animals. For the BCG, there was little bone neoformation activity in the initial periods, and from day 30 onwards, there was an increase in bone neoformation, with a greater increase on day 60. The data obtained in the histometric analysis reveal that, on day 30, the neoformed bone area did not vary greatly between the PCG and the BCG, though both varied from the CG. By day 60, the PCG presented a greater area of neoformation than the BCG. These results were corroborated by the immunohistochemistry results. In view of the results obtained, it can be concluded that all membranes studied in this research promoted GBR.

Physicochemical Characterization of Five Different Bone Graft Substitutes Used in Periodontal Regeneration: An In Vitro Study

Background:

Periodontal regeneration involves using a variety of bone graft substitutes (BGS) of varying origin and manufacturing processes. These include a wide range of biomaterials that are mainly of two types: the xenografts and alloplasts. The efficacy of these BGS depends upon the physical characteristics such as particle size, porous nature, surface morphology, as well as the chemical characteristics like composition, crystallinity and resorption properties.

Aims:

The present study is a descriptive study that focuses on describing the physicochemical characteristics of five selected commercially available BGS that are frequently used in periodontal regeneration procedures. The BGS studied here included two xenografts (colocast and osseograft) and three alloplasts (B-OstIN, biograft HABG active and biograft HT).

Materials and Methods:

The physical properties of the BGS, including particle size, morphology, and surface topography, were analyzed using SEM. The mineral phases and crystallinity of the BGS were analyzed using XRD.

Results:

The results showed that the xenografts (colocast and osseograft) had minimal mineral composition and crystalline structure. The physical properties such as surface roughness and porosity were less compared to alloplastic materials. The alloplasts (B-OstIN, biograft HABG and biograft HT) that had different chemical compositions showed varying physical and crystalline properties. Biograft HT showed a superior porous scaffold architecture among all BGS studied.

Conclusion:

It is important for a clinician to have a thorough understanding about the physicochemical characteristics of BGS they use in periodontal regeneration. The xenografts evaluated here had minimal physical and crystalline properties. Among the alloplasts studied, biograft HT showed superior physicochemical properties, while the presence of bioactive glass in biograft HABG enhanced regeneration.

Impact of different regenerative techniques and materials on the healing outcome of endodontic surgery: a systematic review and meta-analysis

BACKGROUND

Regenerative techniques are increasingly applied in endodontic surgery, but different materials used in regenerative techniques may have varying impacts on wound healing.

OBJECTIVES

This study evaluated the effects of different regenerative techniques and materials on the outcome of endodontic surgery.

PARTICIPANTS

patients with persistent periapical lesions, treated with root-end surgery.

CONTROL

endodontic surgery without the use of regenerative techniques/materials.

INTERVENTION

endodontic surgery with the use of regenerative techniques/materials.

OUTCOME

combined clinical and radiographic results.

METHODS

PubMed, Web of Science, Embase, SinoMed and the CENTRAL Cochrane were searched up to 10th July 2020, followed by a manual search. Detailed eligibility criteria were applied. Cochrane's risk-of-bias tool 2.0 was used to assess the risk of bias of the eligible studies. Meta-analysis was conducted using RevMan software. Subgroup analyses were performed based on the regenerative materials used in endodontic surgery.

RESULTS

Eleven eligible randomized controlled trials (RCTs) were included in the meta-analysis: two had a low risk of overall bias, and nine had some concerns of overall bias. Generally, the use of regenerative techniques significantly improved the outcome of endodontic surgery (risk ratio [RR]: 0.42; 95% confidence interval [CI], 0.26-0.68; P < 0.001). On subgroup analysis, the use of expanded polytetrafluoroethylene (e-PTFE) membranes alone had no added benefits (RR: 2.00; 95% CI, 0.22-18.33; P = 0.54). The application of collagen membranes or autologous platelet concentrates (APCs) alone was associated with a trend for better outcomes (RR: 0.51; 95% CI, 0.20-1.25; P = 0.14) (RR: 0.55; 95% CI, 0.18-1.71; P = 0.30). The combined use of collagen membranes and bovine-derived hydroxyapatite significantly improved the outcome (RR: 0.35; 95% CI, 0.17-0.75; P = 0.007).

DISCUSSION

This systematic review evaluated the effects of collagen membranes, e-PTFE membranes, APCs and bone grafting materials, providing detailed information about the risks and benefits of using each regenerative technique/material or its combination in endodontic surgery.

CONCLUSIONS

Regenerative techniques improve periapical lesion healing after endodontic surgery. The combined use of collagen membranes and bovine-derived hydroxyapatite may be beneficial as an adjunct to endodontic surgery. In contrast, the positive efficacy of e-PTFE membranes or APCs alone remains doubtful.

Comparison of Effects of Curcumin and Nano-curcumin on the Survival of Human-Derived Mesenchymal Stem Cells: An Experimental Study

Aim:

To evaluate and compare the effect of curcumin (CUR) and Nano-curcumin (N-CUR) on human-derived mesenchymal stem cells (MSCs) in a dose-dependent manner.

Materials and Methods:

An experimental study performed with putative MSCs from a total of five systemically healthy subjects with chronic periodontitis. These putative MSCs were isolated by cell culture and were further characterized and identified by colony-forming unit assay and immunocytochemical analysis using cell surface markers CD105, CD146, CD45 and CD73. The identified MSCs were treated with different doses of CUR and N-CUR, and compared with α-minimum essential medium (α -MEM) for its cell viability by performing MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay for 48 and 72 hr. The statistically analysis was performed using one-way analysis of variance (ANOVA) followed by Tukey’s post hoc test and Bonferroni’s post hoc test.

Results:

Compared to the α-MEM group, both CUR and N-CUR treated cells have shown significantly ( P = .029) higher survival rate at lower concentration (0.1 and 0.5 µM/L), at 48 hr incubation. However, there was no statistically significant difference between the CUR and N-CUR groups on cell survival rate at both 48 and 72 hr incubation. When compared between the concentrations of the same group, significantly higher cell viability ( P = .001) was observed at lower concentrations (0.1, 0.5 µM/L) in both test groups after incubation for 48 and 72 hr.

Conclusion:

Both CUR and N-CUR have a dose-dependent effect on human derived MSCs survival when incubated for 48 hr, whereas N-CUR shows increased cell survival rate even at 72 hr of incubation. Although, the cautious use of CUR and N-CUR at higher concentrations is recommended.

Palatal root surgery of a maxillary molar using a piezosurgery transantral approach with simultaneous sinus lift grafting: a case report

AIM

To report a case involving transantral palatal root piezoelectric surgery followed by a sinus floor augmentation procedure with the purpose of minimizing and managing complications associated with sinus lining perforations and optimizing bone regeneration at the site of the surgical defect.

SUMMARY

An asymptomatic 28-year-old male patient with the diagnosis of chronic apical periodontitis on a previously root filled right maxillary first molar (FDI tooth 16) and second premolar (No. 15) was managed by transantral apical surgery. Cone-beam computerized tomography (CBCT) revealed the position of the palatal root of the first molar within the maxillary sinus. The case highlights the management of the palatal root and the handling of a perforation of the Schneiderian membrane through a combination of piezosurgery and a sinus lift grafting procedure involving a second-generation of platelet concentrates. No postoperative complications were observed. Sinus bone augmentation after a 26-month recall period was confirmed by CBCT in the clinically asymptomatic teeth.

KEY LEARNING POINTS

The selective bone tissue cutting and enhanced visibility obtained by piezoelectric surgery in comparison with current rotary techniques make this technology the preferred tool for apical surgery when the mucosal lining of the maxillary sinus could be compromised. The wound healing and physical properties of the platelet-rich fibrin membranes in combination with an allograft material can be considered as sinus bone graft options when a transantral approach is performed on a palatal root of a maxillary molar. A preoperative tomographic examination is essential for apical surgery using a transantral approach with sinus bone augmentation, because of the information obtained from the axial and coronal views on the CBCT scan.

The Effect of Cross-linking Efficiency of Drug-Loaded Novel Freeze Gelated Chitosan Templates for Periodontal Tissue Regeneration

Innovative strategies for periodontal regeneration have been the focus of research clusters across the globe for decades. In order to overcome the drawbacks of currently available options, investigators have suggested a novel concept of functionally graded membrane (FGM) templates with different structural and morphological gradients. Chitosan (CH) has been used in the past for similar purpose. However, the composite formulation of composite and tetracycline when cross-linked with glutaraldehyde have received little attention. Therefore, the purpose of the study was to investigate the drug loading and release characteristics of novel freeze gelated chitosan templates at different percentages of glutaraldehyde. These were cross-linked with 0.1 and 1% glutaraldehyde and loaded with doxycycline hyclate. The electron micrographs depicted porous morphology of neat templates. After cross-linking, these templates showed compressed ultrastructures. Computerized tomography analysis showed that the templates had 88 to 92% porosity with average pore diameter decreased from 78 to 44.9 μm with increasing concentration. Fourier transform infrared spectroscopy showed alterations in the glycosidic segment of chitosan fingerprint region which after drug loading showed a dominant doxycycline spectral composite profile. Interestingly, swelling profile was not affected by cross-linking either at 0.1 and 1% glutaraldehyde and template showed a swelling ratio of 80%, which gained equilibrium after 15 min. The drug release pattern also showed a 40 μg/mL of release after 24 h. These doxycycline-loaded templates show their tendency to be used in a functionally graded membrane facing the defect site.

Pulp-Dentin Tissue Healing Response: A Discussion of Current Biomedical Approaches

Dental pulp tissue exposed to mechanical trauma or cariogenic process results in root canal and/or periapical infections, and conventionally treated with root canal procedures. The more recent regenerative endodontic procedure intends to achieve effective root canal disinfection and adequate pulp–dentin tissue regeneration; however, numerous limitations are reported. Because tooth is composed of vital soft pulp enclosed by the mineralized hard tissue in a highly organized structure, complete pulp–dentin tissue regeneration has been challenging to achieve. In consideration of the limitations and unique dental anatomy, it is important to understand the healing and repair processes through inflammatory-proliferative-remodeling phase transformations of pulp–dentin tissue. Upon cause by infectious and mechanical stimuli, the innate defense mechanism is initiated by resident pulp cells including immune cells through chemical signaling. After the expansion of infection and damage to resident pulp–dentin cells, consequent chemical signaling induces pluripotent mesenchymal stem cells (MSCs) to migrate to the injury site to perform the tissue regeneration process. Additionally, innovative biomaterials are necessary to facilitate the immune response and pulp–dentin tissue regeneration roles of MSCs. This review highlights current approaches of pulp–dentin tissue healing process and suggests potential biomedical perspective of the pulp–dentin tissue regeneration.

Mesenchymal stem cell-based tissue regeneration therapies for periodontitis

Periodontitis is commonly observed and is an important concern in dental health. It is characterized by a multifactorial etiology, including imbalance of oral microbiota, mechanical stress, and systemic diseases such as diabetes mellitus. The current standard treatments for periodontitis include elimination of the microbial pathogen and application of biomaterials for treating bone defects. However, the periodontal tissue regeneration via a process consistent with the natural tissue formation process has not yet been achieved. Developmental biology studies state that periodontal tissue is composed of neural crest-derived ectomesenchyme. To elucidate the process of periodontal regeneration, it is essential to understand the developmental background and intercellular cross-talk. Several recent studies have reported the efficacy of transplantation of mesenchymal stem cells for periodontal tissue regeneration. In this review, we discuss the basic knowledge of periodontal tissue regeneration using mesenchymal stem cells and highlight the potential of stem cell-based periodontal regenerative medicine.

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Neural crest cells regulate the development and homeostasis of periodontal tissues.

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Dental mesenchymal stem cells (MSCs) are used for treating alveolar bone defects.

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Non-odontogenic MSCs can be investigated for periodontal tissue regeneration.

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Using appropriate growth factors and scaffold may improve periodontium regeneration.

Prevention of Bone Resorption by HA/β-TCP + Collagen Composite after Tooth Extraction: A Case Series

After tooth extraction, alveolar ridge loss due to resorption is almost inevitable. Most of this bone loss occurs during the first six months after the extraction procedure. Many studies have indicated that applying socket-filling biomaterials after extraction can effectively reduce the resorption rate of the alveolar ridge. The purpose of this study was to investigate the clinical efficacy of the application of a hydroxyapatite/β-tricalcium plus collagen (HA/β-TCP + collagen) dental bone graft in dental sockets immediately after tooth extraction, so as to prevent socket resorption. The study was conducted on 57 extraction sockets located in the mandible and maxilla posterior regions in 51 patients. HA/β-TCP + collagen was inserted into all of the dental sockets immediately after extraction, and was covered with a flap. Follow-up was performed for three months after extraction, using radiographs and stents for the vertical and horizontal alveolar ridge measurements. A minimal alveolar bone width reduction of 1.03 ± 2.43 mm (p < 0.05) was observed. The height reduction showed a slight decrease to 0.62 ± 1.46 mm (p < 0.05). Radiographically, the bone height was maintained after three months, indicating a good HA/β-TCP + collagen graft performance in preserving alveolar bone. In conclusion, the HA/β-TCP + collagen graft demonstrated adequate safety and efficacy in dental socket preservation following tooth extraction.

Improvement of the Physical Properties of Guided Bone Regeneration Membrane from Porcine Pericardium by Polyphenols-Rich Pomace Extract

To achieve optimal performances, guided bone regeneration membranes should have several properties, in particular, proper stiffness and tear resistance for space maintenance, appropriate resorption time, and non-cytotoxic effect. In this work, polyphenol-rich pomace extract (PRPE), from a selected grape variety (Nebbiolo), rich in proanthocyanidins and flavonols (e.g., quercetin), was used as a rich source of polyphenols, natural collagen crosslinkers, to improve the physical properties of the porcine pericardium membrane. The incorporation of polyphenols in the collagen network of the membrane was clearly identified by infra-red spectroscopy through the presence of a specific peak between 1360-1380 cm-1. Polyphenols incorporated into the pericardium membrane bind to collagen with high affinity and reduce enzymatic degradation by 20% compared to the native pericardium. The release study shows a release of active molecules from the membrane, suggesting a possible use in patients affected by periodontitis, considering the role of polyphenols in the control of this pathology. Mechanical stiffness is increased making the membrane easier to handle. Young's modulus of pericardium treated with PRPE was three-fold higher than the one measured on native pericardium. Tear and suture retention strength measurement suggest favorable properties in the light of clinical practice requirements.

Guided Tissue Regeneration in Surgical Endodontic Treatment: Case Report and Literature Review

Background/Aim: Guided tissue regeneration is widely used in endodontic surgery. The aim is to aid in the healing process and bone regeneration and provide more successful and predictable outcomes.

Case report: This case report describes the successful treatment of an endodontic-periodontal lesion (with primary endodontic involvement), including root canal retreatment and endodontic surgery with the use of GTR (collagen absorbable membrane-xenogeneic bone graft). CBCT examination was used to aid in diagnosis and in the follow-up examination after two years to provide additional confirmation of the healing process. An extensive literature review was undertaken focusing on clinical studies that assessing the added benefit of GTR in surgical endodontics. The clinical and radiographic examinations showed uneventful healing and the reconstruction of the buccal plate and periapical area. The patient remained asymptomatic throughout the entire two years period after surgical intervention. A literature review concluded that lesion type, lesion size and the selection of the biomaterial are important factors that influence the outcome of GTR in comparison control groups. A favorable outcome was found in cases of large periapical lesions (>10mm), through-through lesions and with the use of an absorbable membrane, with or without a bone graft.

Conclusions: GTR is thought to provide an added benefit in bone regeneration and the healing process in specific cases. The outcomes in the case report are consistent with the conclusions of literature review.

Biomaterials, Current Strategies, and Novel Nano-Technological Approaches for Periodontal Regeneration

Periodontal diseases involve injuries to the supporting structures of the tooth and, if left untreated, can lead to the loss of the tooth. Regenerative periodontal therapies aim, ideally, at healing all the damaged periodontal tissues and represent a significant clinical and societal challenge for the current ageing population. This review provides a picture of the currently-used biomaterials for periodontal regeneration, including natural and synthetic polymers, bioceramics (e.g., calcium phosphates and bioactive glasses), and composites. Bioactive materials aim at promoting the regeneration of new healthy tissue. Polymers are often used as barrier materials in guided tissue regeneration strategies and are suitable both to exclude epithelial down-growth and to allow periodontal ligament and alveolar bone cells to repopulate the defect. The problems related to the barrier postoperative collapse can be solved by using a combination of polymeric membranes and grafting materials. Advantages and drawbacks associated with the incorporation of growth factors and nanomaterials in periodontal scaffolds are also discussed, along with the development of multifunctional and multilayer implants. Tissue-engineering strategies based on functionally-graded scaffolds are expected to play an ever-increasing role in the management of periodontal defects.

Successful Management of Teeth with Different Types of Endodontic-Periodontal Lesions

Endodontic-periodontal diseases often present great challenges to the clinician in their diagnosis, management, and prognosis. Understanding the disease process through cause-and-effect relationships between the pulp and supporting periodontal tissues with the aid of rational classifications leads to successful treatment outcomes. In this report, we present several treatment modalities in patients with different endodontic-periodontal lesions. A modification to the new endodontic-periodontic classification, Al-Fouzan's classification, was also added. The first case was classified as retrograde periodontal disease (i.e., primary endodontic lesion with drainage through the periodontal ligament). The second case was diagnosed as an iatrogenic periodontal lesion caused by root perforation. The third case was diagnosed as an iatrogenic periodontal lesion caused by tooth trauma due to orthodontic treatment. The first two cases were managed with a nonsurgical approach, whereas the third case was managed with nonsurgical and surgical approaches. All patients showed complete healing of soft and hard tissue lesions. A thorough understanding of the disease history and the patient's signs and symptoms, complete examination with full investigation, and the use of a systematic step-by-step approach in the management of such challenging endodontic-periodontal lesions with regular recall visits were very useful and successful.

Effects of vitamin D status on oral health

Normal humans of all ages have the innate ability to produce vitamin D following sunlight exposure. Inadequate vitamin D status has shown to be associated with a wide variety of diseases, including oral health disorders. Insufficient sunlight exposure may accelerate some of these diseases, possibly due to impaired vitamin D synthesis. The beneficial effects of vitamin D on oral health are not only limited to the direct effects on the tooth mineralization, but are also exerted through the anti-inflammatory functions and the ability to stimulate the production of anti-microbial peptides. In this article, we will briefly discuss the genesis of various oral diseases due to inadequate vitamin D level in the body and elucidate the potential benefits of safe sunlight exposure for the maintenance of oral and general health.

Guided bone regeneration with asymmetric collagen-chitosan membranes containing aspirin-loaded chitosan nanoparticles

Introduction

Membranes allowing the sustained release of drugs that can achieve cell adhesion are very promising for guided bone regeneration. Previous studies have suggested that aspirin has the potential to promote bone regeneration. The purpose of this study was to prepare a local drug delivery system with aspirin-loaded chitosan nanoparticles (ACS) contained in an asymmetric collagen-chitosan membrane (CCM).

Methods

In this study, the ACS were fabricated using different concentrations of aspirin (5 mg, 25 mg, 50 mg, and 75 mg). The drug release behavior of ACS was studied. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to examine the micromorphology of ACS and aspirin-loaded chitosan nanoparticles contained in chitosan-collagen membranes (ACS-CCM). In vitro bone mesenchymal stem cells (BMSCs) were cultured and critical-sized cranial defects on Sprague-Dawley rats were made to evaluate the effect of the ACS-CCM on bone regeneration.

Results

Drug release behavior results of ACS showed that the nanoparticles fabricated in this study could successfully sustain the release of the drug. TEM showed the morphology of the nanoparticles. SEM images indicated that the asymmetric membrane comprised a loose collagen layer and a dense chitosan layer. In vitro studies showed that ACS-CCM could promote the proliferation of BMSCs, and that the degree of differentiated BMSCs seeded on CCMs containing 50 mg of ACS was higher than that of other membranes. Micro-computed tomography showed that 50 mg of ACS-CCM resulted in enhanced bone regeneration compared with the control group.

Conclusion

This study shows that the ACS-CCM would allow the sustained release of aspirin and have further osteogenic potential. This membrane is a promising therapeutic approach to guiding bone regeneration.

Combination of hydroxyapatite, platelet rich fibrin and amnion membrane as a novel therapeutic option in regenerative periapical endodontic surgery: Case series

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Our article was an attempt to focus on combined benefits of Bio-Gen mix^®, PRF and amnion membrane to provide a viable regenerative option in periapical surgery.

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To the best of our knowledge, there has been no evidence related to the application of a human placental membrane in periapical surgery. Our presented case reports provide an insight into this novel therapeutic option.

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The presented case reports confirm that the amnion membrane combined with bone graft and PRF have enhanced the healing outcomes and provided endodontists a sustainable tool while performing surgeries in the esthetic zone.

Introduction

Periapical surgery is the last resort in the arsenal of an endodontist to effectively deal with periapical lesions that result from necrosis of the pulp. Bone grafts, growth factors and membranes form an array of regenerative materials that influence the healing outcome of periapical surgery.

Presentation of case

The main purpose of the two cases reported here was to assess the potential benefits of a combination of bone graft, platelet-rich fibrin (PRF) and amnion membrane in terms of reduced post-operative discomfort, radiographic evidence of accelerated periapical bone healing and present a novel therapeutic option in the management of large periapical lesions. Two cases of radicular cysts were treated through a combined regenerative approachof Bio-Gen mix^®, PRF and amnion membrane. The patients were assessed for discomfort immediate post-operatively and after a week. The patients were recalled every month for the next 6 months for radiographic assessment of the periapical healing.

Discussion

Literature is replete with articles that have substantiated the role of demineralized bone matrix comprising a mixture of cancellous and cortical bone graft particles in enhancing regeneration. To the best of our knowledge, there has been no evidence related to the application of a human placental membrane in periapical surgery. Hence, the rationale of using a combined approach of Bio-Gen mix^®, PRF and amnion membrane was to combine the individual advantages of these materials to enhance clinical and radiographic healing outcomes. Our present case reports provide an insight into this novel therapeutic option.

Conclusion

The results of this case seriessubstantiatesthe credibility of using a combination ofamnion membrane with a bone graft and PRF to enhance radiographic healing outcome with decreased post-operative discomfort and present a viable regenerative treatment modality in periapical surgery.

Bone Regeneration Induced by Bone Porcine Block with Bone Marrow Stromal Stem Cells in a Minipig Model of Mandibular "Critical Size" Defect

Introduction. Adding stem cells to biodegradable scaffolds to enhance bone regeneration is a valuable option. Different kinds of stem cells with osteoblastic activity were tested, such as bone marrow stromal stem cells (BMSSCs). Aim. To assess a correct protocol for osteogenic stem cell differentiation, so BMSSCs were seeded on a bone porcine block (BPB). Materials and Methods. Bone marrow from six minipigs was extracted from tibiae and humeri and treated to isolate BMSSCs. After seeding on BPB, critical-size defects were created on each mandible of the minipigs and implanted with BPB and BPB/BMSSCs. After three months, histomorphometric analysis was performed. Results. Histomorphometric analysis provided percentages of the three groups. Tissues present in control defects were 23 ± 2% lamellar bone, 28 ± 1% woven bone, and 56 ± 4% marrow spaces; in BPB defects were 20 ± 5% BPB, 32 ± 2% lamellar bone, 24 ± 1% woven bone, and 28 ± 2% marrow spaces; in BPB/BMSSCs defects were 17 ± 4% BPB/BMSSCs, 42 ± 2% lamellar bone, 12 ± 1% woven bone, and 22 ± 3% marrow spaces. Conclusion. BPB used as a scaffold to induce bone regeneration may benefit from the addition of BDPSCs in the tissue-engineered constructs.

Antibacterial efficacy of triple-layered poly(lactic-co-glycolic acid)/nanoapatite/lauric acid guided bone regeneration membrane on periodontal bacteria

A guided bone regeneration (GBR) membrane has been extensively used in the repair and regeneration of damaged periodontal tissues. One of the main challenges of GBR restoration is bacterial colonization on the membrane, constitutes to premature membrane degradation. Therefore, the purpose of this study was to investigate the antibacterial efficacy of triple-layered GBR membrane composed of poly(lactic-co-glycolic acid) (PLGA), nanoapatite (NAp) and lauric acid (LA) with two types of Gram-negative periodontal bacteria, Fusobacterium nucleatum and Porphyromonas gingivalis through a disc diffusion and bacterial count tests. The membranes exhibited a pattern of growth inhibition and killing effect against both bacteria. The increase in LA concentration tended to increase the bactericidal activities which indicated by higher diameter of inhibition zone and higher antibacterial percentage. It is shown that the incorporation of LA into the GBR membrane has retarded the growth and proliferation of Gram-negative periodontal bacteria for the treatment of periodontal disease.

Periodontal tissue engineering: current strategies and the role of platelet rich hemoderivatives

Periodontal tissue engineering procures to regenerate the periodontal tissue assuring the right combination of scaffolds, biochemical cues and cells. The platelet rich hemoderivatives might provide the adequate growth factors and structural proteins for the predictable regeneration of periodontium.

Guided Tissue Regeneration in Four Teeth Using a Liquid Polymer Membrane

Periodontal disease is one of the most common diseases diagnosed in dogs and cats. Guided tissue regeneration (GTR) is a treatment alternative to extraction of strategically important teeth. The barrier membrane used in the GTR procedure is of key importance. The purpose of this case series was to evaluate a liquid polymer gel as a membrane for GTR. The polymer gel ( N-methyl-2-pyrrolidone and poly [DL-lactide]) combined with 8.5% doxycycline hyclate was used in place of a traditional membrane in 4 teeth. The teeth were re-examined 6 months postoperatively for radiographic evaluation. A decrease in probing depth and new alveolar bone formation was seen 6 months postoperatively. Improvement in periodontal disease stage was seen in 2 of the 4 teeth. Larger controlled trials with histopathologic evaluation are indicated to further assess the use of this polymer as a membrane in GTR. However, the clinical outcomes of all 4 treated teeth were considered successful.

Effects of fibroblast growth factor-2 on cell proliferation of cementoblasts

Background/purpose

Fibroblast growth factor (FGF)-2 is known as a signaling molecule that induces tissue regeneration. Little is known about the effect of FGF-2 on cementoblasts for periodontal and periapical regeneration. The aim of this study was to investigate the effects of FGF-2 on murine immortalized cementoblast cell line (OCCM.30).

Materials and methods

Cell growth and proliferation was judged by using alamar blue reduction assay. Flow cytometry analysis was used to evaluate Stro-1 positive cells expression with or without FGF-2. Western blot was used to evaluate the expression of phosphorylated serine–threonine kinase Akt (p-Akt) and extracellular signal-regulated protein kinase (p-ERK) in cementoblasts.

Results

FGF-2 was found to increase cell growth in a dose-dependent manner (P < 0.05). The concentration of 10 ng/mL FGF-2 enhanced cell proliferation in a time-dependent manner (P < 0.05). In addition, 10 ng/mL FGF-2 significantly increased the number of Stro-1 positive cells in the first 24 hours (P < 0.05). Moreover, 10 ng/mL FGF-2 was found to upregulate p-Akt and p-ERK in a time-dependent manner (P < 0.05).

Conclusion

Taken together, FGF-2 could increase cementoblast growth, proliferation, and Stro-1 positive cells. These enhancements are associated with the upregulation of p-Akt and p-ERK expression. The application of FGF-2 may provide benefit for periodontal and periapical regeneration during the early phase of wound healing.

Novel bioceramic-reinforced hydrogel for alveolar bone regeneration

The osseointegration of dental implants and their consequent long-term success is guaranteed by the presence, in the extraction site, of healthy and sufficient alveolar bone. Bone deficiencies may be the result of extraction traumas, periodontal disease and infection. In these cases, placement of titanium implants is contraindicated until a vertical bone augmentation is obtained. This goal is achieved using bone graft materials, which should simulate extracellular matrix (ECM), in order to promote osteoblast proliferation and fill the void, maintaining the space without collapsing until the new bone is formed. In this work, we design, develop and characterize a novel, moldable chitosan-pectin hydrogel reinforced by biphasic calcium phosphate particles with size in the range of 100-300μm. The polysaccharide nature of the hydrogel mimics the ECM of natural bone, and the ceramic particles promote high osteoblast proliferation, assessed by Scanning Electron Microscopy analysis. Swelling properties allow significant adsorption of water solution (up to 200% of solution content) so that the bone defect space can be filled by the material in an in vivo scenario. The incorporation of ceramic particles makes the material stable at different pH and increases the compressive elastic modulus, toughness and ultimate tensile strength. Furthermore, cell studies with SAOS-2 human osteoblastic cell line show high cell proliferation and adhesion already after 72h, and the presence of ceramic particles increases the expression of alkaline phosphatase activity after 1week. These results suggest a great potential of the developed moldable biomaterials for the regeneration of the alveolar bone.

STATEMENT OF SIGNIFICANCE

The positive fate of a surgical procedure involving the insertion of a titanium screw still depends on the quality and quantity of alveolar bone which is present in the extraction site. Available materials are basically hard scaffold materials with un-predictable behavior in different condition and difficult shaping properties. In this work we developed a novel pectin-chitosan hydrogel reinforced with ceramic particles. Polysaccharides simulate the extracellular matrix of natural bone and the extensive in vitro cells culture study allows to assess that the incorporation of the ceramic particles promote a pro-osteogenic response. Shape control, easy adaption of the extraction site, predictable behavior in different environment condition, swelling properties and an anti-inflammatory response are the significant characteristics of the developed biomaterial.

Management of a Previously Treated, Calcified, and Dilacerated Maxillary Lateral Incisor: A Combined Nonsurgical/Surgical Approach Assisted by Cone-beam Computed Tomography

Teeth with calcified canals, dilacerated roots, and associated large periradicular lesions involving both cortical plates pose a challenge to dentists. In addition to the nonsurgical endodontic treatment, such teeth may require surgical intervention with concomitant use of bone grafting materials and barrier techniques. These techniques, when combined with the use of a host modulating agent such as platelet-rich fibrin (PRF), may improve the chances of success. A 26-year-old woman was referred for dental treatment with a recurrence of an intraoral sinus tract 2 months after periradicular surgery in the upper anterior region. Clinical and radiographic examinations revealed a calcified and perforated maxillary left lateral incisor with a severely dilacerated root as well as an associated large radiolucent lesion surrounding the roots of the maxillary left central and lateral incisors. A cone-beam computed tomographic scan of the anterior maxilla showed erosion of the labial and palatal cortical plates in the same region. A calcified canal in the lateral incisor was negotiated up to the straight line portion of the canal. Periradicular surgery with root-end resection was performed, and root-end filling was performed with mineral trioxide aggregate. The perforation present on the middle third of the labial surface of the root was repaired with mineral trioxide aggregate, and the canal was cleaned, shaped, and obturated. A PRF scaffold was prepared and used with a collagen membrane and a freeze-dried bone allograft. Follow-up visits after 3 months, 6 months, and 1 year revealed satisfactory clinical and radiographic healing. The combined use of nonsurgical and surgical modes of treatment cannot be overemphasized in this case. The use of PRF along with a bone graft and a barrier membrane may have enhanced the speed of healing and the resolution of periradicular radiolucency by enhancing bone regeneration.

Active Nanofibrous Membrane Effects on Gingival Cell Inflammatory Response

Alpha-melanocyte stimulating hormone (α-MSH) is involved in normal skin wound healing and also has anti-inflammatory properties. The association of α-MSH to polyelectrolyte layers with various supports has been shown to improve these anti-inflammatory properties. This study aimed to evaluate the effects of nanofibrous membrane functionalized with α-MSH linked to polyelectrolyte layers on gingival cell inflammatory response. Human oral epithelial cells (EC) and fibroblasts (FB) were cultured on plastic or electrospun Poly-#-caprolactone (PCL) membranes with α-MSH covalently coupled to Poly-L-glutamic acid (PGA-α-MSH), for 6 to 24 h. Cells were incubated with or without Porphyromonas gingivalis lipopolysaccharide (Pg-LPS). Cell proliferation and migration were determined using AlamarBlue test and scratch assay. Expression of interleukin-6 (IL-6), tumor necrosis factor (TNF-α), and transforming growth factor-beta (TGF-β) was evaluated using RT-qPCR method. Cell cultures on plastic showed that PGA-α-MSH reduced EC and FB migration and decreased IL-6 and TGF-β expression in Pg-LPS stimulated EC. PGA-α-MSH functionalized PCL membranes reduced proliferation of Pg-LPS stimulated EC and FB. A significant decrease of IL-6, TNF-α, and TGF-β expression was also observed in Pg-LPS stimulated EC and FB. This study showed that the functionalization of nanofibrous PCL membranes efficiently amplified the anti-inflammatory effect of PGA-α-MSH on gingival cells.

Chitosan nanoparticles enhance the antibacterial activity of chlorhexidine in collagen membranes used for periapical guided tissue regeneration

Endodontic failure is mainly associated with the persistence of microbial infection in the root canal system and/or the periradicular area. Microorganisms and their toxins located in the root canal system may trigger apical periodontitis and tissue destruction. Tissue regeneration in periapical surgery by using membrane barriers has shown an improved healing and bone closure. However, bacterial membrane contamination is a main reason of failure. In this in vitro study, different brands of chlorhexidine, a combination of chitosan nanoparticles containing chlorhexidine were tested against Enterococcus faecalis on agar plate's cultures and infected collagen membranes. Our results indicated that chitosan nanoparticles acted synergistically with chlorhexidine, inhibiting and eliminating significantly a greater amount of colony former units in both BHI-agar cultures and infected collagen membranes. These results suggested that chitosan nanoparticles could be used to improve regenerative procedures in periapical surgery.

Combination of Mineral Trioxide Aggregate and Platelet-rich Fibrin Promotes the Odontoblastic Differentiation and Mineralization of Human Dental Pulp Cells via BMP/Smad Signaling Pathway

INTRODUCTION

Recent reports have shown that the combined use of platelet-rich fibrin (PRF), an autologous fibrin matrix, and mineral trioxide aggregate (MTA) as root filling material is beneficial for the endodontic management of an open apex. However, the potential of the combination of MTA and PRF as an odontogenic inducer in human dental pulp cells (HDPCs) in vitro has not yet been studied. The purpose of this study was to evaluate the effect of the combination of MTA and PRF on odontoblastic maturation in HDPCs.

METHODS

HDPCs extracted from third molars were directly cultured with MTA and PRF extract (PRFe). Odontoblastic differentiation of HDPCs was evaluated by measuring the alkaline phosphatase (ALP) activity, and the expression of odontogenesis-related genes was detected using reverse-transcription polymerase chain reaction or Western blot. Mineralization formation was assessed by alizarin red staining.

RESULTS

HDPCs treated with MTA and PRFe significantly up-regulated the expression of dentin sialoprotein and dentin matrix protein-1 and enhanced ALP activity and mineralization compared with those with MTA or PRFe treatment alone. In addition, the combination of MTA and PRFe induced the activation of bone morphogenic proteins (BMP)/Smad, whereas LDN193189, the bone morphogenic protein inhibitor, attenuated dentin sialophosphoprotein and dentin matrix protein-1 expression, ALP activity, and mineralization enhanced by MTA and PRFe treatment.

CONCLUSIONS

This study shows that the combination of MTA and PRF has a synergistic effect on the stimulation of odontoblastic differentiation of HDPCs via the modulation of the BMP/Smad signaling pathway.