Enamel Matrix Derivative Research Articles

Enamel matrix derivative in the treatment of tooth replantation: from a biological basis to clinical application

Background An efficient therapeutic strategy for patients with replanted teeth has been extremely challenging because complete displacement of the teeth is inevitably accompanied by severe damage to periodontal tissue. Enamel matrix derivative (EMD) shows promise for periodontal regeneration, but its effects on replanted teeth remain unknown. This study systematically summarized the biological basis of EMD in replantation dental therapy and assessed its effect on clinical prognosis. Methods Potential studies were searched via the Cochrane Library, Web of Science and PubMed databases from inception to November 23, 2023. Results A total of 329 patients with 375 replanted teeth met the inclusion criteria. Our pooling results indicated that EMD did not provide a numerical advantage for restoring normal PDL healing in replanted teeth (RR=0.38, P=0.161). A significantly lower extraction risk was observed in EMD-treated group than non-EMD-treated group (RR=0.47, P=0.001). Moreover, the survival rate of replanted teeth with root resorption was significantly increased by the application of EMD (RR=2.21, P=0.017). Although the pooled outcomes suggested increased incidence of surface resorption (RR=1.19, P=0.730) and decreased risk of inflammation resorption (RR=0.68, P=0.560) among replanted teeth with resorption in the EMD-treated group, neither difference was statistically significant. Conclusion For patients with replanted teeth, EMD treatment may not result in a numerical increase in normal PDL healing. However, as a biological regulator, EMD may arrest the progression of resorption, thus reducing the risk of extraction in the early stage. Well-designed randomized trials are required to validate these results due to the poor quality of evidence.

Case report: non-surgical regeneration with adjunctive enamel matrix derivative

A 48-year-old female patient referred to the Birmingham Dental Hospital for generalized periodontitis presented with a residual 8-mm pocket and infrabony defect around her LL2 after Step 1 and 2 of therapy. Following discussion of treatment options, a minimally invasive non-surgical technique was completed alongside the addition of a biologic, a therapeutic agent applied to enhance regenerative or reparative effects during wound healing and in this case, enamel matrix derivative. At 6 months, pocket closure was evident, as well as radiographic evidence of bony infill. The patient remains in ongoing supportive periodontal therapy at 3-monthly intervals. CPD/Clinical Relevance: Addition of biologics traditionally used during surgical therapy may provide improvements when used alongside minimally invasive non-surgical treatment.

A Novel Nano-Hydroxyapatite Agarose-Based Hydrogel for Biomimetic Remineralization of Demineralized Human Enamel: An in-vitro Study.

This study aims to investigate the biomimetic effect of agarose hydrogel loaded with enamel matrix derivative (EMD-agarose) alone or in combination with nano-hydroxyapatite (n-HA-EMD-agarose) on the remineralization of human demineralized enamel. Extracted human mandibular third molars were sectioned into 54 buccal and lingual halves. Acid-resistant nail varnish was applied to each half, except for two enamel windows. Enamel surface microhardness, energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM) analyses were conducted to evaluate enamel surfaces at baseline, following demineralization with 37% phosphoric acid, and after each hydrogel application and remineralization for two, four, and six days. Remineralization was performed using a phosphate solution at 37°C. At day 6 following remineralization, a statistically significant higher mean microhardness was recorded in n-HA-EMD-agarose hydrogel (260.87 ± 3.52) as compared to EMD-agarose hydrogel (244.63 ± 2.76) (p = 0.027). Similarly, n-HA-EMD-agarose hydrogel showed a higher mean calcium (46.31 ± 2.78), phosphorous (24.92 ± 0.826), and fluoride (0.909 ± 0.053) weight percentage compared to EMD-agarose hydrogel calcium (19.64 ± 1.092), phosphorous (19.64 ± 1.092), and fluoride (0.7033 ± 0.0624) weight percentage (p < 0.05). Further, SEM analysis revealed a substantial deposition of n-HA following the application of the n-HA-EMD-agarose hydrogel, whereas the EMD-agarose exhibited a relatively smooth enamel surface with less visible enamel rods due to mineral deposition. The combined n-HA-EMD-agarose hydrogel demonstrated improved surface microhardness of the remineralized enamel and enhanced mineral content deposition, indicating its potential as a biomimetic approach for dental enamel repair.

Microbial Dynamics in Periodontal Regeneration: Understanding Microbiome Shifts and the Role of Antifouling and Bactericidal Materials: A Narrative Review

Periodontal regeneration is a multifaceted therapeutic approach to restore the tooth-supporting structures lost due to periodontal diseases. This manuscript explores the intricate interactions between regenerative therapies and the oral microbiome, emphasizing the critical role of microbial balance in achieving long-term success. While guided tissue regeneration (GTR), bone grafting, and soft tissue grafting offer promising outcomes in terms of tissue regeneration, these procedures can inadvertently alter the oral microbial ecosystem, potentially leading to dysbiosis or pathogenic recolonization. Different grafting materials, including autografts, allografts, xenografts, and alloplasts, influence microbial shifts, with variations in the healing timeline and microbial stabilization. Biologics and antimicrobials, such as enamel matrix derivatives (EMD) and sub-antimicrobial dose doxycycline (SDD), play a key role in promoting microbial homeostasis by supporting tissue repair and reducing pathogenic bacteria. Emerging strategies, such as enzyme-based therapies and antifouling materials, aim to disrupt biofilm formation and enhance the effectiveness of periodontal treatments. Understanding these microbial dynamics is essential for optimizing regenerative therapies and improving patient outcomes. The future of periodontal therapy lies in the development of advanced materials and strategies that not only restore lost tissues but also stabilize the oral microbiome, ultimately leading to long-term periodontal health.

Coronal Cementum and Reduced Enamel Epithelium on Occlusal Surface of Impacted Wisdom Tooth in a Human

Background: There is only limited research on the coronal cementum of a tooth, and the mechanisms of its forming process are not well-defined. This report presents a coronal cementum on the occlusal surfaces of enamel in an impacted wisdom tooth in a human, which is not nearly the cervical portion. Materials and Methods: The tooth (Tooth #1) was derived from a 46-year-old female. Histological analysis, including hematoxylin and eosin (HE) and toluidine blue (TB) staining, and Scanning Electron Microscopy and Energy Dispersive X-ray Spectrometer (SEM-EDS) analysis of the extracted tooth were conducted. Radiographic examination showed that Tooth #1 was horizontally impacted in the maxilla and had the apex of a single root placed between the buccal and palatal roots of Tooth #2. Results: Coronal cementum was distributed widely on the enamel, and reduced enamel epithelium was also found with enamel matrix proteins histologically. The formation of acellular cementum was observed to be more predominant than that of the cellular cementum in Tooth #1. SEM showed that the occlusal cementum connected directly with enamel. Calcium mapping revealed an almost similar occlusal cementum and enamel. In addition, the spectrum of elements in coronal cementum resembled the primary cementum according to SEM-EDS. Discussion: Thus, coronal cementogenesis in impacted human teeth might be related to the existence of reduced enamel epithelium.

Effects of i-PRF, A-PRF+, and EMD on Osteogenic Potential of Osteoblasts on Titanium.

The study evaluates three biologically active substances with known bone-inductive potential on previously decontaminated titanium (Ti) discs. Rough and smooth Ti surfaces were contaminated with a multispecies biofilm and cleaned with a chitosan brush. Discs were treated either with injectable-platelet-rich fibrin (i-PRF), advanced platelet-rich fibrin (A-PRF+), or enamel matrix derivatives (EMDs) before osteoblast seeding. Biocompatibility, adhesion, migration, and gene expression of runt-related transcription factor 2 (RUNX2), collagen Type I Alpha 2 (COL1a2), alkaline phosphatase (ALP), osteocalcin (OC), and osteonectin (ON) were performed. All the tested biologic agents similarly increased cell viability. Specifically, osteoblasts seeded over i-PRF and EMD-treated surfaces showed improvement in adhesion and migration and significantly increased ALP, OC, ON, RUNX-2, and COL1a2 mRNA levels up to 2.8 fold (p < 0.05) with no differences between Ti surfaces. i-PRF and EMD possess beneficial bioactive properties that enhance tissue healing and promote regeneration on thoroughly sterilized surfaces. Biologically active materials may hold the potential to influence the process of implant re-osseointegration, which warrants more research since sterilization of the affected surfaces under clinical conditions is still not reliably possible and remains one of the greatest challenges.

Management of intrabony defects using enamel matrix derivative

Management of intrabony defects using enamel matrix derivative

Deletion within ameloblastin multitargeting domain reduces its interaction with artificial cell membrane

In human, mutations in the gene encoding the enamel matrix protein ameloblastin (Ambn) have been identified in cases of amelogenesis imperfecta. In mouse models, perturbations in the Ambn gene have caused loss of enamel and dramatic disruptions in enamel-making ameloblast cell function. Critical roles for Ambn in ameloblast cell signaling and polarization as well as adhesion to the nascent enamel matrix have been supported. Recentely, we have identified a multitargeting domain (MTD) in Ambn that interacts with cell membrane, with the majority enamel matrix protein amelogenin, and with itself. This domain includes an amphipathic helix (AH) motif that directly interacts with cell membrane. In this study, we analyzed the sequence of the MTD for evolutionary conservation and found high conservation among mammals within the MTD and particularly within the AH motif. We computationally predicted that the AH motif lost its hydrophobic moment upon deleting hydrophobic but not hydrophilic residues from the motif. Furthermore, we rationally designed peptides that encompassed the Ambn MTD and contained deletions of largely hydrophobic or hydrophilic stretches of residues. To assess their AH-forming and membrane-binding abilities, we combined those peptides with synthetic phospholipid membrane vesicles and performed circular dichroism, membrane leakage, and vesicle clearance measurements. Circular dichroism showed retention of α-helix formation in all peptides except the one with the largest deletion of eleven amino acids including seven that were hydrophobic. This same peptide variant failed to cause leakage or clearance of synthetic membranes, while smaller deletions yielded intermediate membrane interaction as measured by leakage and clearance assays. Our data revealed that deletion of key hydrophobic residues from the AH leads to the most dramatic loss of Ambn–membrane interaction. Pinpointing roles of residues within the MTD has important implications for the multifunctionality of Ambn.

The Potential of Enamel Matrix Derivative in Countering Bisphosphonate-Induced Effects in Osteoblasts.

The suppressive effect of bisphosphonates (BPs) on bone metabolism is considered to be a major cause of medication-related osteonecrosis of the jaw (MRONJ). Enamel matrix derivative (EMD) stimulates and activates growth factors, leading to the regeneration of periodontal tissues. In this study, we aimed to explore the potential of EMD in reversing the detrimental effects of BPs on human fetal osteoblasts (hFOBs) and osteosarcoma-derived immature osteoblasts (MG63s) by assessing cell viability, apoptosis, migration, gene expression, and protein synthesis. While the suppressive effect of zoledronate (Zol) on cell viability and migration was observed, the addition of EMD significantly mitigated this effect and enhanced cell viability and migration. Furthermore, an increased apoptosis rate induced by Zol was decreased with the addition of EMD. The decreased gene expression of alkaline phosphatase (ALP), osteocalcin (OC), and the receptor activator of nuclear factors kappa-B ligand (RANKL) caused by BP treatment was reversed by the co-addition of EMD to hFOB cells. This trend was also observed for ALP and bone sialoprotein (BSP) levels in MG63 cells. Furthermore, suppressed protein levels of OC, macrophage colony-stimulating factor (M-CSF), BSP, and type 1 collagen (COL1) were recovered following the addition of EMD. This finding suggests that EMD could mitigate the effects of BPs, resulting in the recovery of cell survival, migration, and gene and protein expression. However, the behavior of the osteoblasts was not fully restored, and further studies are necessary to confirm their effects at the cellular level and to assess their clinical usefulness in vivo for the prevention and treatment of MRONJ.

Biologics Agents in Periodontal Regeneration:A Review

The field of periodontology and dental implantology has witnessed significant advancements in the use of molecular mediators and biologic agents over the past decade. Periodontal regeneration, which involves the complete restoration of cementum, bone, and connective tissue following removal of epithelial tissues, is considered superior to tissue repair. Recent research has focused on utilizing biologic materials as complementary therapies to enhance regeneration by accelerating wound healing. These biologic agents were investigated using the following search terms: tissue engineering, intercellular signaling molecules, and biological factors. Enamel matrix derivative (EMD), platelet-derived growth factor (PDGF), platelet-rich plasma, bone morphogenetic proteins (BMPs), fibroblast growth factor (FGF), and parathyroid hormone (PTH) have demonstrated the capacity to stimulate both hard and soft tissue regeneration. However, no single biologic agent is universally effective, necessitating a case-by-case evaluation for optimal treatment selection. Currently, EMD and PDGF are the only biologic therapies approved by the FDA for periodontal regeneration, while BMP-2 is indicated for bone augmentation. Due to a lack of FDA approval for periodontal applications, the clinical use of FGF and PTH in this context is not recommended.

Treatment of Localized Gingival Recession with an Enamel Matrix Protein-Coated Xenogeneic Dermal Matrix: A Randomized Controlled Trial.

This study aims to evaluate the influence of the additional use of enamel matrix derivate (EMD) in the treatment of gingival recession defects using a coronally advanced flap (CAF) and a xenogeneic dermal matrix (XDM) by means of digital and clinical assessment methods. In this prospective randomized controlled study, recession height and area, width and thickness of keratinized gingiva, pocket probing depth, and clinical attachment levels were measured at the baseline and followed up for one year. Fifteen patients (n = 15) with 24 gingival recession defects were treated between 2019 and 2021. On average, the digitally assessed root coverage of the control group (CAF + XDM) was not significantly different compared to the test group (CAF + XDM + EMD), with 69 ± 28% and 36 ± 32%, respectively (p = 0.094). One year postoperatively, there were no differences found regarding keratinized tissue width (KTW) between the control group and test group (p = 0.690). However, the control group showed superior results in the thickness of keratinized gingiva (p = 0.044). The present study showed that there were no statistically significant differences in the root coverage results in the CAF + XDM + EMD group compared to the CAF + XDM group. The adjunctive use of EMD to a CAF and XDM in the treatment of gingival recession defects does not appear to have any clinical benefit.

Impact of Freeze-dried Corticocancellous Bone Allograft Combined with Enamel Matrix Derivative in the Treatment of Critical-sized Calvarial Bone Defects: An Animal Study.

This study compared the quality and quantity of newly formed bone in rabbits' critical-sized calvarial defects filled with enamel matrix derivative (EMD) combined with freeze-dried bone allograft (FDBA) vs FDBA alone. A total of 24 adult male white New Zealand rabbits were included. In each rabbit, three bone defects with a diameter of 8 mm were created on the calvarium bone; the first defect was left untreated, while the second was filled with FDBA, and the third was filled with EMD + FDBA. Twelve rabbits were randomly euthanized after a month, and the remaining 2 month postsurgery. Bone sections were histologically evaluated by hematoxylin and eosin and vascular endothelial growth factor (VEGF), alkaline phosphatase (ALP), osteoprotegerin (OPG), and receptor activator of NF-kappaB (RANK) immune-histochemical staining. An improvement in the newly formed bone percentage was found in the defects filled with EMD + FDBA in comparison with FDBA and control defects at 1 month and 2 months postsurgery. Additionally, the expression of VEGF, ALP, OPG, and RANK showed highly significant differences in the defects filled with EMD + FDBA compared to the FDBA and control ones at 1 month postsurgery (p = 0.001). Meanwhile, VEGF and ALP expression showed a significant decrease in defects filled with EMD + FDBA compared to the FDBA and control ones (p = 0.001), while OPG and RANK expression showed non-significant differences between treated groups at 2 months postsurgery. Enamel matrix derivative combined with FDBA has a synergistic effect on bone formation and graft substitution. This combination accelerates the expression of VEGF, ALP, OPG, and RANK. The combination of EMD and FDBA accelerates and ameliorates the quality of newly formed bone, aiding in maxillofacial reconstruction. How to cite this article: Zakri RN, Grawish ME, Mowafey B, et al. Impact of Freeze-dried Corticocancellous Bone Allograft Combined with Enamel Matrix Derivative in the Treatment of Critical-sized Calvarial Bone Defects: An Animal Study. J Contemp Dent Pract 2024;25(5):424-431.

Recombinant human amelogenin promotes wound healing by enhancing angiogenesis

The first barrier of the human body is the skin, and more serious harm may occur when skin wound healing is delayed. One of the components of enamel matrix proteins is amelogenin, which inhibits inflammation and promotes periodontal tissue regeneration. However, its role in skin wound healing and angiogenesis is inconclusive. Thus, this study aimed to assess the therapeutic effect of recombinant human amelogenin (rhAM) on mouse skin wounds and to determine its effect on angiogenesis and its underlying mechanism. rhAM was expressed in Escherichia coli and purified using the optimized acetic acid method. A skin injury mouse model was established to explore the effects of rhAM on skin wound healing. After treatment with rhAM for 7 days, the wound healing rate was calculated, and the therapeutic effect of rhAM on skin wounds was assessed using hematoxylin & eosin (HE), Masson, and CD31 immunofluorescence staining. The expression of growth and inflammatory factors in wound tissues were detected using Western Blot. In addition, the rhAM effects on the proliferation and migration of human umbilical vein endothelial cells (HUVEC) and mouse fibroblasts (NIH 3T3) were studied in vitro using the Cell Counting Kit-8, cell scratch, cytoskeleton staining, and qPCR. The rhAM effect on HUVEC angiogenesis and its potential mechanism was studied using tube formation and Western Blot. The results showed that the purity of the obtained rhAM was more than 90 % using the optimized acetic acid method, and high-dose rhAM treatment could improve wound healing rate in mice. Additionally, more blood vessels and collagen were produced in the skin wound, and the expression of angiopoietin-related protein 2 (ANGPTL2) and transforming growth factor (TGF)-β1 was upregulated; however, that of interleukin-6 was down-regulated. We also found that rhAM promoted the proliferation and migration of HUVEC and NIH 3T3, the mRNA levels of vascular endothelial growth factor (VEGF), fibroblast growth factor, TGF-β1 and ANGPTL2 in HUVEC cells were upregulated, and expression of VEGF and phosphorylation of the p38 mitogen-activated protein kinase were activated. Therefore, rhAM could promote skin wound healing by upregulating angiogenesis and inhibiting inflammation.

Staged Regenerative-Phenotype Modification Therapy for Multiple RT3 Gingival Recessions in Periodontally Compromised Anterior Mandibular Teeth: A Case Report.

We report the successful treatment of multiple recession type (RT) 3 gingival recessions in periodontally compromised mandibular anterior teeth with limited keratinized tissue. A 35-yearold man with stage III, grade C periodontitis underwent a two-stage intervention. Initially, a modification of the connective tissue graft (m-CTG) wall technique was used as part of phenotype modification therapy. The CTG acted as a protective 'wall,' securing space for periodontal regeneration, enhancing root coverage, soft tissue thickness, and keratinized mucosal width. Recombinant human fibroblast growth factor-2 and carbonate apatite promoted periodontal regeneration. This procedure successfully facilitated periodontal regeneration, resulting in the transition from RT3 to RT2 gingival recession and adequate keratinized mucosal width. Eighteen months later, the second surgery used a tunneled coronally advanced flap (TCAF) for root coverage. TCAF involved combining a coronally advanced flap and tunnel technique by elevating the trapezoidal surgical papilla and using a de-epithelialized CTG inserted beneath the tunneled flap. Root conditioning with ethylenediaminetetraacetic acid and enamel matrix derivative gel application were performed. Consequently, mean CAL gain was 5.3 mm, mean root coverage was 4.5 mm in height, and the gingival phenotype improved at the treated sites by the 12-month follow-up. This staged approach addresses the challenges of treating RT3 gingival recession with promising outcomes.

Enamel matrix proteins in promoting saliva lubrication

Anti-wear performance of human enamel in the mouth is closely related to the lubrication of salivary pellicle. It is well known that the inorganic hydroxyapatite (HA) of the enamel plays an important role in the adsorption and pellicle-forming of salivary proteins on the enamel, but the role of enamel matrix proteins remains unclear. In this study, the adsorption and lubrication behavior of salivary proteins on original, heated, and deproteinated enamel surfaces was comparatively investigated using an atomic force microscopy and nano-indentation/scratch techniques. Compared with that on the original enamel surface, the adsorption and lubrication behavior of salivary proteins remains almost unchanged on the heated enamel surface (where the enamel matrix proteins are denatured but the size of HA crystalline nanoparticles keeps constant) but exhibits an obvious compromise on the deproteinated enamel surface (where the enamel matrix proteins are removed and agglomeration of HA crystallites occurs). The HA agglomeration weakens the electrostatic interaction of enamel surfaces with salivary proteins to cause a distinct negative influence on the adsorption and pellicle-forming of salivary proteins. Further, the negative effect is confirmed with a quartz crystal microbalance with dissipation. In summary, by regulating enamel nanostructure for appropriate electrostatic interactions between salivary proteins and enamel surfaces, the enamel matrix proteins play an essential role in the adsorption and pellicle-forming of salivary proteins on human enamel, and then contribute to saliva lubrication, which provides the enamel with an anti-wear mechanism. The findings will promote and assist the design of enamel-inspired anti-wear materials.

Peri-implantitis induction and resolution around zirconia versus titanium implants.

This study compared titanium and zirconia implant ligature-induced peri-implant defect progression and response to regenerative surgical intervention. Eight tissue-level endosseous implants were placed in 6 mixed-breed foxhounds, with 2 zirconia and 2 titanium alternating in each hemimandible. Cotton ligatures were placed subgingivally for 16weeks followed by 8weeks of spontaneous progression. Standardized radiographs were captured every 2weeks to evaluate the rate of bone loss. Regenerative surgery was performed utilizing water-jet decontamination, enamel matrix derivative, and locally harvested autogenous bone. After 16weeks of healing, final radiographic bone levels as well as probing depths, recession, and clinical attachment levels were assessed. All 48 implants integrated successfully. The final average post-ligature radiographic defects were 2.88 and 3.05mm for titanium and zirconia implants, respectively. There was no significant difference between materials in the rate of radiographic bone loss (p=0.09). Following regenerative surgery, the total average amount of radiographic bone gain was 1.41 and 1.20mm for titanium and zirconia, respectively. The percentage of defect fill was 51.56% and 37.98% (p=0.03) for titanium and zirconia, respectively. Inter-group differences were minimal for clinical parameters at the time of sacrifice including periodontal pocket depths (p=0.81), recession (p=0.98), or clinical attachment levels (p=0.51). No significant difference was found in the rate of peri-implant defect development between titanium and zirconia implants. Both materials gained significant radiographic bone following regenerative surgery with significantly greater defect percentage fill in titanium implants. The final clinical parameters were similar in both groups.

Clinical and Radiographic Evaluation of Intrabony Periodontal Defects Treated with Hyaluronic Acid or Enamel Matrix Proteins: A 6-Month Prospective Study.

To compare the regenerative clinical and radiographic effects of cross-linked hyaluronic acid (xHyA) with enamel matrix proteins (EMD) at six months after regenerative treatment of periodontal intrabony defects. Sixty patients presenting one intrabony defect each were randomly assigned into control (EMD) and test (xHyA) groups. Clinical attachment level (CAL) gain was the primary outcome, while pocket probing depth (PPD), gingival recession (REC), bleeding on probing (BOP), full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS), and radiographic parameters such as defect depth (BC-BD), and defect width (DW) were considered secondary outcome variables. Parameters were recorded at baseline and after 6 months. At the 6-month follow-up, 54 patients were available for statistical analysis. In the control and test groups, the mean CAL gain was statistically significant in the intragroup comparison (p < 0.001). 48.1% of test sites showed a CAL gain ≤ 2 mm compared with 33.3% of control sites. The mean PPD reduction was statistically significant in the intragroup comparison in both groups (p < 0.001). The mean REC increase was similar in the two groups: 1.04 ± 1.29 mm vs 1.11 ± 1.22 mm (test vs control). The mean BC-BD, DW, FMPS, FMBS, and BOP changed statistically significantly only in the intragroup comparison, not in the intergroup comparison. Both treatments, EMD and xHyA, produced similar statistically significant clinical and radiographical improvements after six months when compared with baseline.

Recombinant human enamelin produced in Escherichia coli promotes mineralization in vitro

BackgroundEnamelin is an enamel matrix protein that plays an essential role in the formation of enamel, the most mineralized tissue in the human body. Previous studies using animal models and proteins from natural sources point to a key role of enamelin in promoting mineralization events during enamel formation. However, natural sources of enamelin are scarce and with the current study we therefore aimed to establish a simple microbial production method for recombinant human enamelin to support its use as a mineralization agent.ResultsIn the study the 32 kDa fragment of human enamelin was successfully expressed in Escherichia coli and could be obtained using immobilized metal ion affinity chromatography purification (IMAC), dialysis, and lyophilization. This workflow resulted in a yield of approximately 10 mg enamelin per liter culture. Optimal conditions for IMAC purification were obtained using Ni2+ as the metal ion, and when including 30 mM imidazole during binding and washing steps. Furthermore, in vitro mineralization assays demonstrated that the recombinant enamelin could promote calcium phosphate mineralization at a concentration of 0.5 mg/ml.ConclusionsThese findings address the scarcity of enamelin by facilitating its accessibility for further investigations into the mechanism of enamel formation and open new avenues for developing enamel-inspired mineralized biomaterials.

Tooth autotransplantation with adjunctive application of enamel matrix derivatives using a digital workflow: A prospective case series

ObjectivesDigital protocols and bioactive materials may reduce complications and improve tooth autotransplantation (ATT) success and survival rates. This prospective study assesses the performance of a fully digital autotransplantation protocol of close-apex molars with the adjunctive application of Enamel Matrix Derivatives (EMD). MethodsTwelve adult patients with 13 hopeless molar teeth were replaced with autotransplantation of closed apex third molars. Outcomes, including success and survival rates, clinical, endodontic, radiographic, patient-reported outcome measures (PROMs), and digital image assessments, were conducted over a two-year follow-up period. ResultsSurvival and success rates were 100% and 91.2%, respectively, with no progressive inflammatory or replacement root resorption (ankylosis) except for one tooth presenting radiographic furcation involvement. A significant probing depth reduction of 2.4 ± 2.58 mm and CAL gains of 2.8 ± 3.03 mm were observed in transplanted teeth compared to the hopeless receptor teeth. Radiographic bone levels remained stable throughout the study period (-0.37 ± 0.66 mm), and digital image assessments showed minimal alveolar ridge width changes (-0.32 to -0.7 mm) and gingival margin changes (-0.95 to -1.27 mm) from baseline to last visit. PROMs indicated very high patient satisfaction. ConclusionThe use of a digital ATT protocol with adjunctive use of EMD in closed-apex third molars demonstrated promising short-term high success and survival rates. Additionally, this type of therapy adequately preserves the dimensions of the alveolar ridge in the receptor site. Clinical significanceThis is the first prospective clinical study examining the effect of a digital tooth autotransplantation protocol combined with the application of EMD. It demonstrates that this approach is an effective treatment for replacing hopeless teeth and also validates the digital assessment of ATT alveolar ridge preservation at the recipient site.

The flapless approach with and without enamel matrix derivatives for the treatment of intrabony defects: A randomized controlled clinical trial.

To compare the clinical and radiographic outcomes of flapless procedure alone or in combination with enamel matrix derivatives (EMD) in the treatment of deep intrabony defects. Forty-six patients re-evaluated after non-surgical therapy were randomly assigned to the test (flapless with EMD) or control group (flapless alone). Clinical measurements were recorded pre-surgery and at 6 and 12 months after surgery, and radiographic measurements were taken pre-surgery and after 12 months. Forty-six patients completed the study. Improvements were observed in both groups at 12 months for mean clinical attachment level (CAL) gain, with significant differences between test (3.9 ± 1.1 mm) and control groups (3.0 ± 1.2) (p = .017). Probing pocket depth (PPD) reduction (4.0 ± 0.7 vs. 3.3 ± 1.4 mm) was also near to statistical significance (p = .051). Also, more sites achieved successful composite outcome measure (final PPD ≤ 4 mm and CAL gain ≥3 mm) for the regenerative treatment in the flapless + EMD group (82.6% vs. 52.2%; p = .028). In terms of radiographic outcomes, EMD yielded a greater defect bone fill than flapless treatment alone (3.0 ± 1.0 mm vs. 1.8 ± 1.5 mm; p < .001). The additional application of EMD during the flapless procedure for intrabony defects slightly improved clinical and radiographic outcomes. gov identification number: NCT05456555.