Enamel matrix derivative, inflammation and soft tissue wound healing

The Use of Enamel Matrix Derivative during Surgical Therapy for Peri-Implantitis: A Case Series

Peri-implantitis is a growing concern and currently, there is no agreement on the best method for treating this condition. This study looked at surgical intervention with the use of enamel matrix derivative (EMD) for treating this condition. A cohort of 25 (34 implants) consecutive patients treated with EMD for peri-implantitis was followed for up to 6.4 years. The survival of the implants as well as changes in clinical parameters are reported. Statistical analysis was performed using paired t tests and general estimating equations. The mean length of time implants were followed post-surgery was 3.05 ± 1.53 years. All but two of the treated implants survived in function (94%). Both failed implants were lost in the same patient, who was a heavy smoker. The changes in mean probing depth (1.94 ± 1.18 mm), change in deepest probing depth (3.12 ± 1.45 mm), and reduction in bleeding on probing (73.6 ± 43.9%) according to patient means were all highly significant (p < 0.001 for all changes). When EMD is used during surgical treatment of peri-implantitis, there is a high survival rate of implants and significant improvements in clinical parameters.

Effects of enamel matrix derivative in nonsurgical periodontal therapy on pro-inflammatory profiles, microbial environment and clinical outcome: a randomized clinical trial

OBJECTIVES

This study aimed to evaluate the impact of enamel matrix derivative (EMD) application following subgingival instrumentation of residual pockets in periodontitis patients on inflammatory host response, microbiological composition, and clinical outcome.

METHODS

In this double-blinded randomized controlled trial, a total of 22 patients with generalized periodontitis stage III or IV presenting with ≥ 6 mm probing pocket depth (PPD) at re-evaluation after initial periodontal therapy were included. Participants were randomly allocated at a 1:1 ratio to subgingival instrumentation with (EMD +) or without (EMD-) non-surgical EMD application into the pocket. PPD, clinical attachment level (CAL), bleeding on probing (BoP), plaque index (PI), as well as a panel of pro-inflammatory cytokines and periodontal pathogen count in the gingival crevicular fluid (GCF) of the respective sites were evaluated at baseline (T0) and six months afterwards (T1).

RESULTS

Both treatment groups showed a significant PPD reduction (EMD + 1.33 ± 1.15 mm, p < 0.001; EMD- 1.32 ± 1.01 mm, p < 0.001) as well as CAL gain (EMD + 1.13 ± 1.58 mm, p < 0.001; EMD- 0.47 ± 1.06 mm, p = 0.005) from T0 to T1. While no intergroup differences for PPD reduction were observed, CAL gain was higher in EMD + sites compared to EMD- (p = 0.009). No essential effects on cytokine expression as well as bacterial count were detected.

CONCLUSIONS

Application of EMD as an adjunct to subgingival instrumentation of residual pockets yielded benefits regarding CAL gain; however, effects on PPD reduction, inflammatory cytokines, and bacterial count were negligible.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT04449393), registration date 26/06/2020.

CLINICAL RELEVANCE

Based on the obtained results, additional non-surgical EMD application compared to subgingival instrumentation alone showed no clinically relevant effects on treatment outcome and underlying biological mechanisms.

Enamel Matrix Derivatives as an Adjunct to Alveolar Ridge Preservation-A Systematic Review

PURPOSE

To systematically assess the current evidence regarding the adjunctive application of enamel matrix derivatives (EMDs) during alveolar ridge preservation (ARP) following tooth extraction.

METHODS

A comprehensive literature search was conducted in MEDLINE, Cochrane Library, PsycINFO, Web of Science, Google Scholar, and Scopus to identify relevant randomized controlled clinical trials (RCTs). The primary outcome parameters of this systematic review were histomorphometric and radiographic data; secondary outcomes were the feasibility of implant placement after ARP as well as patient-related outcomes such as postoperative discomfort.

RESULTS

The search identified 436 eligible articles published from 2011 to 2022, but only five were ultimately included for data extraction (146 patients). Given the substantial heterogeneity among the included studies, no meta-analysis could be performed. The authors' qualitative analysis showed marginally improved outcomes regarding an increased percentage of new bone formation after tooth extraction and a reduction in postoperative discomfort.

CONCLUSIONS

Given the potential value of EMDs in other fields of regenerative dentistry, more consideration should be given to EMDs as an adjunctive treatment option in ARP. However, more well-controlled randomized clinical trials are necessary to evaluate the exact potential and impacts of EMDs.

Effects of Enamel Matrix Derivative on Cell Spheroids Made of Stem Cells Obtained from the Gingiva on Osteogenic Differentiation

Background and Objectives: A derivative of the enamel matrix was used to speed up periodontal regeneration, including the formation of new cementum, alveolar bone, and periodontal ligament. In this study, human gingiva-derived stem cell-derived cell spheroids were used to assess the effects of an enamel matrix derivative on cell viability, osteogenic differentiation, and mineralization. Materials and Methods: Human gingiva-derived stem cells were used to create spheroids, which were then coupled with unloaded control groups and an enamel matrix derivative at a final concentration of 2.7, 27, 270, and 2700 μg/mL. The morphological examination of the created stem cell spheroids took place on days 1, 3, 5, and 7. The Live/Dead Kit assay was used to determine the qualitative viability of cells on days 3 and 7. Using the Cell Counting Kit-8, the quantitative vitality of the cell spheroids was assessed on days 1, 3, and 5. On days 7 and 14, alkaline phosphatase activity assays and Alizarin Red S staining were carried out to examine the osteogenic differentiation of the cell spheroids. RUNX2 and COL1A1 expression levels on days 7 and 14 were determined using real-time polymerase chain reaction. Results: The added enamel matrix derivative at the tested concentrations did not significantly alter the morphology of the applied stem cells' well-formed spheroids on day 1. On days 3 and 7, the majority of the spheroids' cells fluoresced green while they were being cultivated. Alkaline phosphatase activity data revealed a substantial rise in the 2700 μg/mL group on day 7 when compared to the unloaded control (p < 0.05). On days 7 and 14, calcium deposits were distinctly seen in each group. In the 27 and 2700 μg/mL groups, the treatment with the enamel matrix derivative resulted in noticeably higher values for the Alizarin Red S staining (p < 0.05). qPCR results showed that adding an enamel matrix derivative to the culture of the 27 μg/mL group raised the level of RUNX2 mRNA expression. Conclusions: These results lead us to the conclusion that a derivative of the enamel matrix may be used to promote osteogenic differentiation in stem cell spheroids.

The therapeutic effects of low-intensity pulsed ultrasound in musculoskeletal soft tissue injuries: Focusing on the molecular mechanism

Musculoskeletal soft tissue injuries are very common and usually occur during both sporting and everyday activities. The intervention of adjuvant therapies to promote tissue regeneration is of great importance to improving people's quality of life and extending their productive lives. Though many studies have focused on the positive results and effectiveness of the LIPUS on soft tissue, the molecular mechanisms standing behind LIPUS effects are much less explored and reported, especially the intracellular signaling pathways. We incorporated all research on LIPUS in soft tissue diseases since 2005 and summarized studies that uncovered the intracellular molecular mechanism. This review will also provide the latest evidence-based research progress in this field and suggest research directions for future experiments.

Efficacy of biologics in root coverage and gingival augmentation therapy: An American Academy of Periodontology best evidence systematic review and network meta-analysis

BACKGROUND

The aim of this systematic review was to assess the efficacy of three biologics, namely autologous blood-derived products (ABPs), enamel matrix derivatives (EMD) and recombinant human platelet-derived growth factor BB (rhPDGF-BB), in root coverage and gingival augmentation therapy.

METHODS

The protocol of this PRISMA 2020-compliant systematic review was registered in PROSPERO (CRD42021285917). After study selection, data of interest were extracted. A network meta-analysis (NMA) was conducted to assess the effect of different surgical interventions on the main clinical outcomes of interest (i.e., mean root coverage [MRC%], complete root coverage [CRC%], keratinized tissue width [KTW], gingival thickness [GT] change, and recession depth [RD] reduction).

RESULTS

A total of 48 trials reported in 55 articles were selected. All studies reported on the treatment of gingival recession defects for root coverage purposes. Forty-six treatment arms from 24 trials were included in the NMA. These arms consisted of treatment with coronally advanced flap (CAF) alone, EMD + CAF, platelet-rich fibrin (PRF) + CAF, and subepithelial connective tissue graft (SCTG) + CAF. Regarding MRC%, SCTG+CAF was associated with a significant higher estimate (13.41%, 95% CI [8.06-18.75], P <  0.01), while EMD+CAF (6.68%, 95% CI [-0.03 to 13.4], P = 0.061) and PRF+CAF (1.03%, 95% CI [-5.65 to 7.72], P = 0.71) failed to show statistically significant differences compared with CAF alone (control group) or with each other. Similarly, only SCTG+CAF led to a significantly higher CRC% (14.41%, 95% CI [4.21 to 24.61], P < 0.01), while treatment arms EMD + CAF (13.48%, 95% CI [-3.34 to 30.32], P = 0.11) and PRF+CAF (-0.91%, 95% CI [-15.38, 13.57], p = 0.81) did not show significant differences compared with CAF alone or with each other. Differences in the CI of PRF+CAF (symmetrical around a zero adjunctive effect) and EMD+CAF (non-symmetrical) suggest that EMD could have some additional value compared with PRF. Treatment with SCTG+CAF led to a statistically significant higher RD reduction (-0.39 mm, 95% CI [-0.55 to 0.22], P < 0.01), however EMD+CAF (-0.13 mm, 95% CI [-0.29 to 0.01], P = 0.08) and PRF+CAF (-0.06 mm, 95% CI [-0.23 to 0.09], P = 0.39) failed to show significant differences compared with CAF or with each other. While SCTG+CAF was associated with a statistically significant higher gain of KTW (0.71 mm, 95% CI [0.48 to 0.93], P < 0.01), EMD+CAF (0.24 mm, 95% CI [-0.02 to 0.51], P = 0.08) and PRF+CAF (0.08 mm, 95% CI [-0.23 to 0.41], P = 0.58) did not result into significant changes compared with CAF alone or with each other. Regarding the use of rhPDGF-BB+CAF, although available studies have reported equivalent results compared with SCTG+CAF, evidence is very limited.

CONCLUSIONS

The use of ABPs, EMD, or rhPDGF-BB in conjunction with a CAF for root coverage purposes is safe and generally promotes significant improvements respective to baseline clinical parameters. However, the adjunctive use of ABPs and EMD does not provide substantial additional improvements in terms of clinical outcomes and patient-reported outcome measures to those achieved using CAF alone, when baseline KTW is >2 mm. Both PRF+CAF and EMD+CAF rendered inferior MRC%, CRC%, RD reduction, and KTW gain compared with SCTG+CAF, which should still be considered the gold-standard in root coverage therapy. Although some studies have reported equivalent results for rhPDGF-BB+CAF compared with the gold-standard intervention, limited evidence precludes formal comparisons with CAF or SCTG+CAF that could be extrapolated to guide clinical practice.

Therapeutic and Metagenomic Potential of the Biomolecular Therapies against Periodontitis and the Oral Microbiome: Current Evidence and Future Perspectives

The principles of periodontal therapy are based on the control of microbial pathogens and host factors that contribute to biofilm dysbiosis, with the aim of modulating the progression of periodontitis and periodontal tissue destruction. It is currently known how differently each individual responds to periodontal treatment, depending on both the bacterial subtypes that make up the dysbiotic biofilm and interindividual variations in the host inflammatory response. This has allowed the current variety of approaches for the management of periodontitis to be updated by defining the goals of target strategies, which consist of reducing the periodontopathogenic microbial flora and/or modulating the host-mediated response. Therefore, this review aims to update the current variety of approaches for the management of periodontitis based on recent target therapies. Recently, encouraging results have been obtained from several studies exploring the effects of some targeted therapies in the medium- and long-term. Among the most promising target therapies analyzed and explored in this review include: cell-based periodontal regeneration, mediators against bone resorption, emdogain (EMD), platelet-rich plasma, and growth factors. The reviewed evidence supports the hypothesis that the therapeutic combination of epigenetic modifications of periodontal tissues, interacting with the dysbiotic biofilm, is a key step in significantly reducing the development and progression of disease in periodontal patients and improving the therapeutic response of periodontal patients. However, although studies indicate promising results, these need to be further expanded and studied to truly realize the benefits that targeted therapies could bring in the treatment of periodontitis.

Challenges and tissue engineering strategies of periodontal guided tissue regeneration

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

Surgical treatment of peri-implantitis with or without adjunctive graft material: a systematic review and meta-analysis of randomized controlled trials

This systematic review and meta-analysis was performed to compare the clinical effect of surgical treatment of peri-implantitis alone or in combination with graft material. Literature searches were conducted up to June 20, 2020. Randomized controlled trials (RCTs) comparing the clinical effects of open flap debridement (OFD) alone and OFD with adjunctive graft materials for the treatment of peri-implantitis were included. Probing depth (PD) changes and marginal bone level (MBL) changes were assessed and expressed as the standardized mean difference (SMD) with 95% confidence interval (CI). Subgroup analyses and sensitivity analyses were conducted. The search yielded 7419 articles, five of which were analysed quantitatively. The adjunctive use of graft materials in OFD did not provide additional PD improvements (SMD 0.46, 95% CI -0.13 to 1.05; P = 0.13), but did yield additional MBL improvements (SMD 1.04, 95% CI 0.71-1.37; P < 0.01). The degradability of the material, number of implants included per patient, and risk of bias did not have significant effects on the results, but the origin of the material may affect the PD improvements. Based on the available evidence, the adjunctive use of graft materials in the surgical treatment of peri-implantitis can significantly improve MBL changes but not PD changes.

Enamel Matrix Derivative Enhances the Odontoblastic Differentiation of Dental Pulp Stem Cells via Activating MAPK Signaling Pathways

The odontoblastic differentiation of dental pulp stem cells (DPSCs) contributes to pulp-dentin regeneration. Enamel matrix derivative (EMD) is considered to be a critical epithelial signal to induce cell differentiation during odontogenesis and has been widely applied to clinical periodontal tissue regeneration. The purpose of this study was to explore the effect of EMD on DPSCs proliferation and odontoblastic differentiation, as well as the underlying mechanisms. We conducted in vitro and in vivo researches to get a comprehensive understanding of EMD. In vitro phase: cell proliferation was assessed by a cell counting kit-8 (CCK-8) assay; then, alkaline phosphatase (ALP) activity and staining, alizarin red staining, real-time RT-PCR, and western blot analysis were conducted to determine the odontoblastic potential and involvement of MAPK signaling pathways. In vivo phase: after ensuring the biocompatibility of VitroGel 3D-RGD via scanning electron microscopy (SEM), the hydrogel mixture was subcutaneously injected into nude mice followed by histological and immunohistochemical analyses. The results revealed that EMD did not interfere with DPSCs proliferation but promoted the odontoblastic differentiation of DPSCs in vitro and in vivo. Furthermore, blocking the MAPK pathways suppressed the EMD-enhanced differentiation of DPSCs. Finally, VitroGel 3D-RGD could well support the proliferation, differentiation, and regeneration of DPSCs. Overall, this study demonstrates that EMD enhances the odontoblastic differentiation of DPSCs through triggering MAPK signaling pathways. The findings provide a new insight into the mechanism by which EMD affects DPSCs differentiation and proposes EMD as a promising candidate for future stem cell therapy in endodontics.

Enamel Matrix Derivatives for Periodontal Regeneration: Recent Developments and Future Perspectives

In the era of the growing population, the demand for dental care is increasing at a fast pace for both older and younger people. One of the dental diseases that has attracted significant research is periodontitis. Periodontal therapy aims to regenerate tissues that are injured by periodontal disease. During recent decades, various pioneering strategies and products have been introduced for restoring or regeneration of periodontal deficiencies. One of these involves the regeneration of tissues under guidance using enamel matrix derivatives (EMDs) or combinations of these. EMDs are mainly comprised of amelogenins, which is one of the most common biological agents used in periodontics. Multiple studies have been reported regarding the role of EMD in periodontal tissue regeneration; however, the extensive mechanism remains elusive. The EMDs could promote periodontal regeneration mainly through inducing periodontal attachment during tooth formation. EMD mimics biological processes that occur during periodontal tissue growth. During root development, enamel matrix proteins are formed on the root surface by Hertwig's epithelial root sheath cells, initiating the process of cementogenesis. This article reviews the challenges and recent advances in preclinical and clinical applications of EMDs in periodontal regeneration. Moreover, we discuss the current evidence on the mechanisms of action of EMDs in the regeneration of periodontal tissues.

Flapless application of enamel matrix derivative in non-surgical periodontal treatment: A systematic review

BACKGROUND AND OBJECTIVE

To assess the effects of the flapless application of enamel matrix derivative (EMD) in combination with non-surgical periodontal treatment (NSPT) when compared to non-surgical periodontal treatment alone in adult patients.

MATERIAL AND METHODS

An electronic literature search was conducted in MEDLINE, Scopus and Cochrane Library up to March 2021 complemented by a manual search. Human longitudinal studies of >5 participants and at least 3 months follow-up were eligible for inclusion in the review. Clinical outcomes were extracted and pooled. Meta-analysis of the included studies was not possible due to methodological differences.

RESULTS

A total of 1199 publications were identified and reviewed for eligibility. Nine of them fulfilled the inclusion criteria. Eight studies were randomized clinical trials. The clinical findings of the majority of the included studies demonstrated that the adjunctive use of EMD with NSPT could lead to significantly improved treatment outcomes including higher PPD reduction, more CAL gain, more robust BOP reduction, higher number of sites with PPD < 5 mm and more frequent pocket closure which reduces the need for further periodontal surgical treatment. Limited biological, microbiological and histological findings were reported. Minimal adverse events were observed.

CONCLUSION

The flapless application of EMD during NSPT leads to an improved clinical outcome in regards to CAL gain and PPD reduction when compared to conventional treatment alone. The potential effect on the biological and microbiological outcome is unclear.

Enamel matrix derivative does not affect osteoclast formation or bone resorption in cultures of mouse bone marrow macrophages or human monocytes

OBJECTIVE

Enamel matrix derivative (EMD) is widely used under the brand name Emdogain^® to promote periodontal regeneration in surgical treatment of periodontitis and peri-implantitis. The molecular mechanisms are unclear, but it has been proposed that EMD has stimulatory effects on the root cementum and periodontal ligament cells. Since dental implants lack these structures, we hypothesized that EMD-induced bone gain involve interactions with osteoclast precursor cells, with consequent inhibitory effect on osteoclast formation and/or activity. The aim was to evaluate this hypothesis.

MATERIAL AND METHODS

Primary mouse bone marrow macrophages (BMMs) and human peripheral blood monocytes were cultured in the presence of receptor activator nuclear factor-κB ligand (RANKL) to stimulate osteoclast formation. A purified Emdogain^® fraction was added to the cell cultures and the effect on number and size of newly formed osteoclasts were evaluated. In cultures on natural bone slices, bioanalytical methods were used to assay osteoclast number and bone resorption.

RESULTS

EMD had a negative effect on osteoclastogenesis in mouse cultures on plastic surface, whereas addition of EMD to osteoclast precursor cells on bone substrate did not affect osteoclast formation or bone resorption.

CONCLUSIONS

The results on natural bone matrix contradict a direct effect of EMD on osteoclast precursor cells.

Effect of Root Surface Biomodification on Multiple Recession Coverage with Modified Coronally Advanced Tunnel Technique and Subepithelial Connective Tissue Graft: A Retrospective Analysis

To improve treatment efficacy of gingival recessions (GR), chemical preparation of the exposed root surface was advocated. The aim of this study was to compare the additional influence of root biomodifications with 24% ethylenediaminetetraacetic acid (EDTA) alone or with enamel matrix derivative (EMD) on the 12 month outcomes of modified coronally advanced tunnel (MCAT) with subepithelial connective tissue graft in the treatment of multiple GR. Average root coverage (ARC), complete root coverage (CRC), reduction in GR, reduction in recession width (RW), gain in clinical attachment level (CAL), increase in gingival thickness (GT), increase in keratinized tissue width (KTW) and changes in root coverage esthetic score (RES) were evaluated. A total of 60 patients with 215 GR were enrolled. In 70, GR root surfaces were treated with EDTA + EMD, in other 72, with EDTA, while in the remaining 73 saline solution was applied. ARC was 94%, 89%, and 91% in the EDTA + EMD, the EDTA and the saline groups, respectively (p = 0.8871). Gains in clinical attachment level (CAL; 2.1 ± 1.1 mm) and RES values (9.6 ± 0.9) were significantly higher in the EDTA + EMD group, when compared with two other groups. The differences between other preoperative and postoperative parameters showed statistical significance only within but not between groups. MCAT outcomes may benefit from adjunctive use of EDTA + EMD regarding 12 month CAL gain and professionally assessed esthetics using RES following treatment of GR.

Connective Tissue Graft with or without Enamel Matrix Derivative for Treating Gingival Recession Defects: A Systematic Review and Meta-Analysis

OBJECTIVES

The aim of this systematic review is to compare the root coverage outcomes of using a connective tissue graft (CTG) with and without the application of enamel matrix derivative (EMD).

METHODOLOGY

An electronic search was performed up to July 2020 in 4 databases, including Ovid MEDLINE, EMBASE, Web of Science and Cochrane Central. Human clinical studies with data on comparing outcomes of root coverage using CTG with and without the application of EMD were included. Meta-analyses for the recorded parameters were performed and the weighted mean difference (WMD) between the 2 groups and 95% confidence interval (CI) were reported.

RESULTS

Nine clinical studies were selected for inclusion in this review. The WMD of clinical attachment level gain was 0.78 mm (95% CI of 0.23-1.34 mm, P = .005) and the WMD of recession depth reduction was 0.28 mm (95% CI of 0.06-0.51 mm, P = .01), favoring the CTG + EMD approach. However, the comparisons for the percentage of complete root coverage and mean root coverage between the 2 approaches were not statistically significant.

CONCLUSION

Although the use of a CTG with and without the application of EMD in root coverage procedures achieved a similar percentage of complete root coverage and mean root coverage, the addition of EMD to CTG may improve the outcome of recession depth reduction and clinical attachment level gain.

Osteoprotective Effect of Enamel Matrix Derivatives on the Regeneration of Mandibular Defects in Experimentally Glucocorticoid-Induced Osteoporosis

Purpose

Osteoporosis is a progressive systematic skeletal illness characterized by low bone mineral density and susceptibility to fracture caused by bone resorption. Aim of the Study. This study intended to evaluate the possible role of emdogain in combination with calcitonin on the healing of surgically induced mandibular defects performed on osteoporotic rats.

Materials and Methods

Forty healthy female white albino rats were included in this study and divided into four groups. In group I (negative control), 10 rats received a vehicle injection after which a unilateral mandibular defect was created in each rat of all groups. Three groups were subjected to induction of osteoporosis by subcutaneous injection of 0.1 mg/kg/day dexamethasone for 60 days. In group II, rats were kept without treatment. In group III, rats were treated with daily intramuscular injection of 2.5 IU/kg of synthetic salmon calcitonin. In group IV, rats were handled as group III, and the created cavity was filled with emdogain. Rats were euthanized at 2nd and 4th week postsurgically. Hematoxylin and eosin, Masson's trichrome, NF-κB (nuclear factor of activated B cells), and immunohistochemical stains were used, followed by statistical analysis.

Results

Group I showed normal stages of bone defects healing. Group II revealed the formation of granulation tissue with dilated blood vessels, while groups III and IV showed enhanced bone healing and proper collagen fibers. The percentage area of newly formed collagen fibers was significantly higher in group IV at 2nd week (13.96 ± 0.020%) and 4th week (16.95 ± 0.024%) than in group II (8.75 ± 0.015% and 10.29 ± 0.015%, respectively) and group III (12.93 ± 0.015% and 14.61 ± 0.021%, respectively), but was lower than that in group I (15.75 ± 0.015% and 17.49 ± 0.015%, respectively).

Conclusion

The local application of emdogain combined with systemically injected calcitonin improves bone healing in surgically induced bone defects in osteoporotic rats.

The Outcomes of Enamel Matrix Derivative on Periodontal Regeneration under Diabetic Conditions

Background and Objectives: Enamel matrix derivative (EMD) is a biomaterial used for periodontal regenerative therapy due to its properties of stimulating cementum development and bone synthesis. Diabetes is a chronic condition that affects healing and predisposes to infection. The aim of this review was to evaluate the current studies available on the application and results of EMD for periodontal regenerative therapy under diabetic conditions. Materials and Methods: Five databases (PubMed, ResearchGate, Scopus, Web of Science and Google Scholar) were searched for relevant articles, using specific keywords in different combinations. The inclusion criteria were clinical trials, case reports, case studies, and animal studies published in English, where periodontal treatment for bone defects includes EMD, and it is performed under diabetic conditions. Results: Of the 310 articles resulted in search, five studies published between 2012 and 2020 met the inclusion criteria and were selected for the current review. In human studies, the use of EMD in infrabony defects showed favorable results at follow-up. In animal studies, periodontal regeneration was reduced in diabetic rats. Conclusions: EMD might promote bone healing when used under diabetic conditions for the regenerative periodontal therapy. Due to limited number of studies, more data are required to sustain the effects of EMD therapy in diabetic settings.

Enamel matrix derivative effects on palatal mucosa wound healing: Randomized clinical trial

BACKGROUND

This study was conducted to evaluate the clinical, immunologic, and patient-centered outcomes of enamel matrix protein derivative (EMD) on excisional wounds in palatal mucosa.

MATERIALS

Forty-four patients in need of ridge preservation were randomly allocated into two groups: control group (n = 22): open palatal wound after free gingival graft (FGG) harvest and EMD group (n = 22): open palatal wound after FGG harvest that received 0.3 ml of EMD. Clinical and patient-centered parameters were analyzed for 3 months post-treatment. Wound fluid levels of inflammatory markers were assessed 3 and 7 days postoperatively.

RESULTS

No significant inter-group difference was observed in remaining wound area and re-epithelialization. EMD and control groups achieved wound closure and re-epithelialization 30 days postoperatively (p < .001), without inter-group differences. Similarly, number of analgesics and Oral Health Impact Profile scores did not present significant inter-group differences (p > .05). EMD appeared to selectively modulate wound fluid levels of monocyte chemoattractant protein-1, macrophage inflammatory protein-1α, matrix metallopeptidase 9, and tissue inhibitor of metalloproteinases-2.

CONCLUSION

Within the limits of the present study, it can be concluded that EMD application to excisional palatal wounds using the investigated protocol does not provide clinical healing benefits, despite an apparent modulation of selected inflammatory markers.

Influence of aging on periodontal regenerative therapy using enamel matrix derivative: A 3-year prospective cohort study

AIM

To investigate the influence of chronological aging on periodontal regenerative therapy (PRT) outcomes with enamel matrix derivative (EMD).

MATERIALS AND METHODS

In total, 253 intra-bony defects (151 patients) including 44 furcation involvement were prospectively investigated for 3 years after regenerative therapy with EMD by evaluating probing pocket depth (PPD), clinical attachment level (CAL), and radiographic bone defect depth (RBD). The influence of age on these outcomes was assessed using multilevel regression analyses adjusting for confounders.

RESULTS

Participants' mean age was 55.9 ± 12.3 years (range: 22-85). Baseline PPD, CAL, and RBD were 6.14 ± 1.82, 7.22 ± 2.14, and 5.08 ± 2.04 mm, respectively. Significant improvement was observed with PPD reductions of 2.84 ± 1.73 and 2.87 ± 1.87 mm, CAL gains of 2.40 ± 1.87 and 2.47 ± 1.89 mm, and RBD gains of 1.76 ± 1.98 and 2.39 ± 2.41 mm at 1- and 3-year examinations, respectively. At the 1-year examination, multivariate analysis revealed a significant negative association between age and improvement in PPD and CAL (coefficients: -0.13, -0.23 mm per 10 years). However, by the 3-year examination, no significant association was noted between age and improvement in PPD, CAL, or RBD.

CONCLUSION

Although the statistical difference was detected with age at 1-year examination, PRT with EMD significantly improved clinical outcomes on long-term observation, irrespective of the patient's age.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000039846.

Papilla preservation periodontal surgery in periodontal reconstruction for deep combined intra-suprabony defects. Retrospective analysis of a registry-based cohort

Background

Suprabony defects are the most prevalent defects and there is very little evidence on their treatment. This study aims to assess the effectiveness of papilla preservation periodontal surgery in the periodontal reconstruction of combined deep intra-suprabony defects.

Material and Methods

20 patients with combined intrabony and supra-alveolar deep periodontal defects treated by papilla preservation periodontal surgery were analyzed. Defects were treated with enamel matrix derivate plus xenograft. Clinical recordings made before surgery and at 12 months.

Results

Papilla preservation periodontal surgery showed significant PPD reduction (4.4 ± 1.46 mm; p<0.001), clinical attachment gain (3.35 ± 1.6 mm; p<0.001), increased REC (1.05 ± 0.94; p<0.001), papilla apical displacement (0.85 ± 1.31 mm; p<0.005) and KT reduction (0.5 ± 0.76 mm; p<0.05). At one week, there was incomplete wound closure and necrosis in 40% and 30% of the treated sites, respectively. At one year, the intrabony component filling was 73.65 ± 27.6 % and the supra-alveolar attachment gain indicated an incomplete intrabony defect resolution (-0.15 ± 1.56 mm).

Conclusions

Periodontal pocket was significantly reduced and the level of clinical attachment increased. However, there was significant recession of the gingival margin and the papilla and a trend to incomplete resolution of the intrabony component.

Key words:Periodontitis, surgical flaps, reconstructive surgery, regeneration.

Cold Atmospheric Plasma Promotes Regeneration-Associated Cell Functions of Murine Cementoblasts In Vitro

The aim of the study was to examine the efficacy of cold atmospheric plasma (CAP) on the mineralization and cell proliferation of murine dental cementoblasts. Cells were treated with CAP and enamel matrix derivates (EMD). Gene expression of alkaline phosphatase (ALP), bone gamma-carboxyglutamate protein (BGLAP), periostin (POSTN), osteopontin (OPN), osterix (OSX), collagen type I alpha 1 chain (COL1A1), dentin matrix acidic phosphoprotein (DMP)1, RUNX family transcription factor (RUNX)2, and marker of proliferation Ki-67 (KI67) was quantified by real-time PCR. Protein expression was analyzed by immunocytochemistry and ELISA. ALP activity was determined by ALP assay. Von Kossa and alizarin red staining were used to display mineralization. Cell viability was analyzed by XTT assay, and morphological characterization was performed by DAPI/phalloidin staining. Cell migration was quantified with an established scratch assay. CAP and EMD upregulated both mRNA and protein synthesis of ALP, POSTN, and OPN. Additionally, DMP1 and COL1A1 were upregulated at both gene and protein levels. In addition to upregulated RUNX2 mRNA levels, treated cells mineralized more intensively. Moreover, CAP treatment resulted in an upregulation of KI67, higher cell viability, and improved cell migration. Our study shows that CAP appears to have stimulatory effects on regeneration-associated cell functions in cementoblasts.

Will mesenchymal stem cells be future directions for treating radiation-induced skin injury?

Radiation-induced skin injury (RISI) is one of the common serious side effects of radiotherapy (RT) for patients with malignant tumors. Mesenchymal stem cells (MSCs) are applied to RISI repair in some clinical cases series except some traditional options. Though direct replacement of damaged cells may be achieved through differentiation capacity of MSCs, more recent data indicate that various cytokines and chemokines secreted by MSCs are involved in synergetic therapy of RISI by anti-inflammatory, immunomodulation, antioxidant, revascularization, and anti-apoptotic activity. In this paper, we not only discussed different sources of MSCs on the treatment of RISI both in preclinical studies and clinical trials, but also summarized the applications and mechanisms of MSCs in other related regenerative fields.

Flapless application of enamel matrix derivative in periodontal retreatment: A multicentre randomized feasibility trial

AIM

To investigate the potential benefit of enamel matrix derivative (EMD) as adjunct to re-instrumentation of residual pockets persisting after steps 1 and 2 of periodontal therapy.

MATERIAL AND METHODS

44 adult patients participated in a multicentre feasibility randomized clinical trial with split-mouth design. They had presented at re-evaluation after initial non-surgical periodontal therapy (steps 1 and 2 of periodontal therapy) for generalized periodontitis with at least 2 teeth with residual probing pocket depths (PPD) ≥5 and ≤8 mm, with bleeding on probing (BOP). Two teeth with similar PPD were randomized to receive re-instrumentation either with (test) or without (control) adjunctive flapless administration of EMD. Differences in the changes of PPD and BOP from baseline to 6 and 12 months were analysed, and the frequencies of pocket closure (PPD ≤4 mm and no BOP) compared.

RESULTS

For the primary outcome "change of mean PPD after 6 months," a significant additional benefit of 0.79 ± 1.3 mm (p < .0001) could be observed for the test group. At 12 months, this difference could be maintained (0.85 ± 1.1 mm; p < .0001). The frequency of pocket closure in the test group was 69% at 6 and 80% at 12 months and significantly higher than in the control group with 34% and 42%, respectively (p < .01).

CONCLUSIONS

The results of the present feasibility study indicate a benefit of adjunctive EMD during non-surgical retreatment (step 3 of periodontal therapy) of residual deep pockets.

Regenerative Potential of Enamel Matrix Protein Derivative and Acellular Dermal Matrix for Gingival Recession: A Systematic Review and Meta-Analysis

Objective: The purpose of this study was to assess the clinical effectiveness of using a combination of enamel matrix protein derivative and acellular dermal matrix in comparison to acellular dermal matrix alone for treating gingival recessions. Methods: The Cochrane Library (Wiley), PubMed by Medline (NLM), Medline (EBSCO), and Embase (Ovid) databases were searched for entries up to April 2020. Only clinical trials were included. Primary outcomes were root coverage (%), changes in keratinized tissue width and recession (mm). Meta-analysis was conducted for root coverage, changes in keratinized tissue width, recession, clinical attachment level and probing depth. Results: Four studies were selected for the analysis. In primary outcomes, root coverage, change in keratinized tissue width and recession analysis showed a mean difference of 4.99% (p = 0.11), 0.20 mm (p = 0.14) and 0.13 mm (p = 0.23) respectively between the two groups. Secondary outcomes analysis also exhibited a statistically insignificant difference between the test and control group with mean difference of 0.11 mm (p = 0.32) in clinical attachment level gain and -0.03 mm (p = 0.29) in probing depth reduction analysis. Conclusions: Within the limits of this study, enamel matrix protein derivative combined with acellular dermal matrix used for treating gingival recession defects resulted in no beneficial effect clinically than acellular dermal matrix only.

Multidisciplinary management of a fused maxillary incisor: Case report with 5-year follow-up

Detailed treatment planning and execution are crucial if regenerative approaches are to be attempted to retain fused permanent teeth. Long-term follow-up is necessary to monitor the stability of the final outcome, both esthetically and functionally.

Effect of enamel matrix derivative on alveolar ridge preservation in the posterior maxilla: A randomized controlled clinical trial

BACKGROUND

EMD has been considered to exert positive effects on wound healing, postoperative discomfort, and bone regeneration.

PURPOSE

The aim of this randomized controlled clinical trial was to investigate and compare (a) horizontal and vertical bone dimensional changes, (b) early postoperative discomfort and soft tissue wound healing outcomes, and (c) treatment modalities for implant placement, following posterior maxillary alveolar ridge preservation (ARP) with and without adjunctive use of EMD.

METHODS

Twenty-eight participants were randomly assigned to three groups: extraction sockets filled with bovine bone mineral and membrane with EMD (test group 1, n = 10) and without EMD (test group 2, n = 10) and spontaneous healing (control group, n = 8). Alveolar bone dimensional changes were measured using cone-beam computed tomography 5 months after ARP, and postoperative pain and wound healing outcomes were also evaluated.

RESULTS

There were no significant differences in horizontal or vertical bone dimensional changes between test groups 1 (horizontal width changes at 1 mm apically below the alveolar ridge crest [HW]: -1.44 ± 0.54 mm) and 2 (HW: -1.42 ± 0.26 mm), but the changes at HW (-2.36 ± 1.03 mm) in the control group were significantly greater than those in test groups 1 and 2 (P < .05). Early postoperative discomfort and soft tissue wound healing outcomes were not significantly different between the two test groups. Furthermore, unlike the control group, both the test groups 1 and 2 were implanted without sinus floor elevation using the lateral approach.

CONCLUSION

Within the limitations of this study, EMD failed to provide additional benefits in ARP in the posterior maxilla.

Tunnel technique with enamel matrix derivative in addition to subepithelial connective tissue graft compared with connective tissue graft alone for the treatment of multiple gingival recessions: a randomized clinical trial

Objectives

The aim of this study was to compare outcomes of the modified coronally advanced tunnel technique (MCAT) combined with subepithelial connective tissue graft (SCTG) with or without enamel matrix derivative (EMD), in the treatment of gingival recession types 1 and 2.

Materials and methods

A total of 20 patients with 150 multiple gingival recessions (GR) were included in the study. On one side, MCAT was combined with SCTG and EMD (tests), whereas MCAT with SCTG was applied on the contralateral side (controls). Clinical parameters were measured at baseline and 6 months after surgery. Visual analog scales (VAS) and questionnaires were used to assess patient-reported outcomes and the root coverage esthetic score (RES) for professional esthetic evaluation.

Results

MCAT+SCTG+EMD was not superior with regard to root coverage. At 6 months, average root coverage (ARC) was 87.4% for SCTG+EMD-treated and 90.9% for SCTG-treated defects (p = 0.4170). Complete root coverage (CRC) was observed in 86.7% (tests) and 85.3% (controls) of the cases (p = 0.9872). Significantly less pain was reported using VAS (p = 0.0342) post-operatively in the SCTG+EMD group. Professional assessment of esthetic outcomes using RES showed a significant difference (9.25 versus 8.71, p = 0.0103) in favor of the test group.

Conclusions

Both treatment modalities were equally effective in treatment of multiple GR and led to similar improvements in clinical parameters. However, the application of EMD as an adjunct resulted in less post-operative pain and better professionally assessed esthetic outcomes.

Clinical relevance

Patients’ early morbidity and 6-month esthetic outcomes following GR coverage with MCAT might be influenced by means of EMD utilization.

Local application of enamel matrix derivative prevents acute systemic inflammation after periodontal regenerative surgery: A randomized controlled clinical trial

AIM

The aim of this study was to compare surgical treatment of periodontal intra-bony defects (IBD) with or without the adjunct of enamel matrix derivative (EMD) in terms of acute-phase responses in healthy patients.

METHODS

Thirty-eight periodontitis-affected subjects, one IDB each, were randomized to minimally invasive periodontal surgery (MIS) with or without EMD. Periodontal parameters were recorded at baseline and 6-months. Blood samples were collected at baseline, 1, 7 and 180 days after treatment.

RESULTS

At 24 hr, the group treated MIS with EMD showed lower values of C-reactive protein (CRP; p < .01) as no inflammatory perturbation was noticed. Conversely, MIS group resulted in an acute inflammatory response at 24 hr (p < .05) that regressed to its baseline values at day 7. The EMD group showed a higher number of cases without residual BOP or PPD ≥ 5mm 6 months after surgery (p < .05), and post-surgical gingival recession was lower (p < .05).

CONCLUSIONS

The adjunctive application of EMD during surgical treatment resulted in a minor increase in serum CRP 24-hr after surgery. These findings suggest a possible systemic anti-inflammatory effect of EMD. Within its limitations, this pilot trial confirmed better clinical periodontal outcomes in the EMD group. NCT03590093.

Potential usefulness of enamel matrix derivative in skin and mucosal injury treatment

Enamel matrix proteins (EMP) are secreted by ameloblasts during odontogenesis. The main component of enamel protein extract is amelogenin. The extracts also contain proteins with bioactive properties similar to bone morphogenic proteins and transforming growth factor β1. Research on animal models indicates that EMP improve healing of oral mucosa wounds by stimulating the production of collagen fibers and blood vessels in the connective tissue. Success in the treatment of oral wounds prompted interest in possible applications of amelogenins in the repair of damaged skin due to similarities in histological structure between skin and mucosa.

Treatment of dehiscence-type defects with collagen matrix and/or enamel matrix derivative: Histomorphometric study in minipigs

BACKGROUND

This study aimed to evaluate, histomorphometrically, the use of collagen matrix (CM) and/or enamel matrix derivative (EMD) for the treatment of dehiscence-type recession defects in minipigs.

METHODS

Eight healthy, male, young BR-1 minipigs, with no periodontal disease were treated. Bilateral dehiscence-type defects were surgically created on the buccal of the mandibular premolars (PI and PII). After 30 days, the defects were randomly assigned to four groups: coronally advanced flap (CAF); CAF + CM; CAF + EMD; and CAF + CM + EMD (split-mouth design). The evaluated parameters (mm): total defect length; new cementum (NC); new bone (NB); gingival margin position; total epithelium length; epithelium on the root; connective tissue adaptation; and soft tissue thickness (STT).

RESULTS

The EMD-treated groups showed a superior length of NC [4.13 ± 1.22 (CAF + EMD); 3.95 ± 1.11 (CAF + CM + EMD); 2.94 ± 0.77 (CAF + CM); 2.72 ± 0.81 (CAF), P = 0.02] and NB [3.21 ± 0.68 (CAF + CM + EMD); 3.01 ± 0.56 (CAF + EMD); 2.15 ± 0.47 (CAF + CM); 2.29 ± 0.82 (CAF), P = 0.005]. The CAF and CAF + CM groups showed a superior epithelial length when compared to EMD-treated groups after 3 months. A superior STT was observed for CAF + CM + EMD group (1.5 ± 0.33) when compared with the other groups [1.09 ± 0.26 (CAF + EMD); 1.04 ± 0.34 (CAF + CM); and 1.14 ± 0.29 (CAF), P = 0.03].

CONCLUSION(S)

The results of the present study indicate that EMD application, irrespective of the combination with CM, may improve the periodontal regeneration of dehiscence-type defects in this animal model.

Enamel matrix derivative stabilizes blood clot and improves clinical healing in deep pockets after flapless periodontal therapy: A Randomized Clinical Trial

AIM

An acute phase response is induced after non-surgical periodontal treatment (SRP). The main aim of this study was to compare acute phase (24-hr) and medium-term (3-months) inflammation and clinical outcomes after SRP with or without application of enamel matrix derivative (EMD) in sites with probing pocket depth (PPD) ≥ 6 mm.

METHODS

Thirty-eight periodontitis-affected subjects were randomized to SRP or SRP + EMD. Periodontal parameters were recorded at baseline and 3 months. Serum samples were collected at baseline, 1 and 90 days after treatment.

RESULTS

Both treatments triggered an intense acute inflammation on day 1, which regressed to baseline values at 3 months. D-dimer and cystatin C levels did not show sharp increases in SRP + EMD group 24 hr after treatment, compared to SRP. Significant difference between groups was observed for D-dimer (p < 0.001). EMD application was also associated with better periodontal healing as shown by greater PPD reduction and clinical attachment level gain in sites with PPD ≥ 6 mm, and higher number of cases with no residual PPD ≥ 6 mm (p < 0.05) at 3 months.

CONCLUSIONS

EMD application after non-SRP resulted in lower fibrinolysis, and better periodontal healing of deep pockets. These initial observations warrant further investigations on the potential to modulate both local and systemic outcomes of non-SRP. NCT03544931.

The use of enamel matrix derivative for the treatment of the apically involved tooth: A case report

INTRODUCTION

The aim of this report is to present a case of an apically involved tooth with successful regeneration by only applying enamel matrix derivative. The root of the tooth was planed and the defect area was well debrided using various instruments, including curettes and an ultrasonic scaler, and the root surface of the tooth and the defect area were loaded with enamel matrix derivative.

PATIENT CONCERNS

A 32-year-old man visited the clinic due to a referral for the evaluation of his mandibular left first molar.

DIAGNOSIS

The clinical and radiographic assessment displayed the loss of the periodontium around the tested tooth with apical involvement of the mesial root. Bleeding upon probing was noted at the mandibular first molar, with the deepest periodontal probing depth of 15 mm.

INTERVENTIONS

A nonsurgical approach was firstly performed on the tooth, and the deepest probing depth was reduced to 12 mm. After re-evaluation, elevation of a full-thickness flap was done, the root of the tooth was planed, and the defect area was well debrided using various instruments, including curettes and an ultrasonic scaler. The defect area on the mandibular left first molar was grafted with enamel matrix derivative.

OUTCOMES

The 7-month postoperative clinical and radiographic evaluation showed healthy gingiva and an increase in radiopacity. The final 1-year and 9-month postoperative evaluation showed that regeneration of bony defect was well maintained up to the final evaluation with reduction of probing depth.

CONCLUSION

In conclusion, a case of apically involved tooth can be treated only with enamel matrix derivative after meticulous debridement with curettes and an ultrasonic scaler.

Periodontal Regenerative Treatment of Intrabony Defects Associated with Palatal Grooves: A Report of Two Cases

A palatal radicular groove (PRG) is a morphological deformity, occurring during tooth development. It is usually located on the palatal aspect of maxillary incisors and frequently associated with periodontal or endodontic-periodontal lesions. Some treatment options were described for such lesions, including primary endodontic treatment and periodontal surgery and extraction with intentional replantation after removal of a PRG and endodontic treatment. The present paper reported two cases of PRG-associated deep intrabony defects, successfully treated with periodontal surgery with enamel matrix derivative (EMD) application and mechanical removal of PRGs, avoiding endodontic treatment or retreatment. The complexity of the diagnostic process was also discussed.

Split-mouth evaluation of connective tissue graft with or without enamel matrix derivative for the treatment of isolated gingival recession defects in dogs

OBJECTIVES

The potential additive effect of an enamel matrix derivative (EMD) to a subepithelial connective tissue graft (CTG) for recession coverage is still controversially discussed. Therefore, the aim of this study was to histologically evaluate the healing of gingival recessions treated with coronally advanced flap (CAF) and CTG with or without EMD in dogs.

MATERIALS AND METHODS

Gingival recession defects (5 mm wide and 7 mm deep) were surgically created on the labial side of bilateral maxillary canines in 7 dogs. After 8 weeks of plaque accumulation and subsequent 2 weeks of chemical plaque control, the 14 chronic defects were randomized to receive either CAF with CTG (CAF/CTG) or CAF with CTG and EMD (CAF/CTG/EMD). The animals were sacrificed 10 weeks after reconstructive surgery for histologic evaluation.

RESULTS

Treatment with CAF/CTG/EMD demonstrated statistically significantly better results in terms of probing pocket depth reduction (P < 0.05) and clinical attachment level gain (P < 0.001). The length of the epithelium was statistically significantly shorter in the CAF/CTG/EMD group than in the CAF/CTG group (1.00 ± 0.75 mm vs. 2.38 ± 1.48 mm, respectively, P < 0.01). Cementum formation was statistically significantly greater in the CAF/CTG/EMD group than following treatment with the CAF/CTG group (3.20 ± 0.89 mm vs. 1.88 ± 1.58 mm, respectively, P < 0.01). The CAF/CTG/EMD group showed statistically significantly greater complete periodontal regeneration (i.e., new cementum, new periodontal ligament, and new bone) than treatment with CAF/CTG (0.54 ± 0.73 mm vs. 0.07 ± 0.27 mm, respectively, P < 0.05).

CONCLUSION

Within their limits, the present findings indicate that the additional use of EMD in conjunction with CAF + CTG favors periodontal regeneration in gingival recession defects.

CLINICAL RELEVANCE

The present findings support the use of EMD combined with CTG and CAF for promoting periodontal regeneration in isolated gingival recession defects.

Combination Therapy for Reconstructive Periodontal Treatment in the Lower Anterior Area: Clinical Evaluation of a Case Series

Clinically, periodontal regeneration may be achieved by the application of barrier membranes, grafts, wound-healing modifiers, and their combinations. Combination therapy refers to the simultaneous application of various periodontal reconstructive treatment alternatives to obtain additive effects. This approach may lead to assemblage of different regenerative principles, such as conductivity and inductivity, space provision and wound stability, matrix development and cell differentiation. The application of autogenous connective tissue grafts during periodontal regenerative treatment with enamel matrix proteins derivative (EMD) has been previously reported. The present case series present a modified approach for treatment of severe periodontally involved lower incisors presenting with thin gingival biotype, gingival recession, minimal attached and keratinized gingiva width and muscle and/or frenum pull. In all cases a combination therapy consisting of a single buccal access flap, root conditioning, EMD application on the denuded root surfaces and a free connective tissue graft was performed. Clinical and radiographic outcomes were consistently satisfactory, leading to probing depth reduction, clinical attachment gain, minimal gingival recession, increased attached and keratinizing gingival width, elimination of frenum and/or muscle pull together with radiographic bone fill of the defects. It may be concluded that the present combination therapy for reconstructive periodontal treatment in the lower anterior area is a valuable alternative for indicated cases.

Enamel matrix derivative for the treatment of partially contained intrabony defects: 12-month results

BACKGROUND

The aim of the study was to evaluate the use of enamel matrix derivative (EMD) alone or in association with deproteinized bovine bone mineral (DBBM) for the treatment of partially contained intrabony defects.

METHODS

A total of 20 two-walled intrabony defects belonging to nine patients were included. Ten defects were treated with EMD alone (test group 1) and the other 10 were treated with EMD and DBBM (test group 2), applying either modified papilla preservation technique or simplified papilla preservation technique.

RESULTS

Twelve months after surgery, in the test group 1, PD was 2.8 ± 0.8 mm, REC was 2.3 ± 2.4 mm and CAL was 5.0 ± 2.8 mm, significantly reduced from baseline values (P < 0.05). Likewise, in test group 2, PD, REC and CAL reduced to 3.0 ± 0.7 mm, 3.9 ± 1.5 mm and 6.9 ± 1.1 mm respectively, from baseline values at 12 months (P < 0.05). No significant differences between groups were found.

CONCLUSIONS

The results showed that the use of EMD alone and the use of a combination of EMD and DBBM for the treatment of partially contained defects showed comparable clinical and radiographic outcomes after 12 months.

Strontium enhances proliferation and osteogenic behavior of periodontal ligament cells in vitro

BACKGROUND AND OBJECTIVE

Strontium (Sr) enhances osteogenic differentiation of certain multipotent cells. Periodontal ligament cells (PDLCs) are known to be multipotent, and Sr might be useful in periodontal bone tissue engineering. This study investigates the effect of high concentration of Sr on the proliferation and osteogenic behavior of PDLCs in vitro.

MATERIAL AND METHODS

Primary human PDLCs were cultured in MEM + 10% FBS without (Ctrl) or with Sr in four diverse concentrations: Sr1, 11.3 × 10^-3  mg/L, human serum physiological level; Sr2, 13 mg/L, typical human serum level after strontium ranelate treatment; Sr3, 130 mg/L, and Sr4, 360 mg/L. The spreading area (2, 4, 6, 24 hours), proliferation rate (1, 3, 7 days), osteogenic behavior (alkaline phosphatase - ALP activity, 7 and 14 days; expression of osteogenic genes, ALP, Runt-related transcription factor 2 - RUNX2, osteopontin - OPN, osteocalcin - OCN, and osteoprotegerin -OPG, 1, 3, 7, 14, 21 days), and formation of mineralized nodules (14 and 21 days) of the PDLCs were assessed. Data were compared group- and period-wise using ANOVA tests.

RESULTS

Periodontal ligament cells cultured with Sr4 showed increased spreading area (after 4 hours), proliferation rate (from 3 days), and OCN and OPN (from 7 days) gene expression as compared to Ctrl, Sr1, Sr2, and Sr3. Sr4 also led to lower ALP activity (from 7 days), ALP (from 3 days), and RUNX2 (at 7 and 14 days) gene expression, together with more evident formation of mineralized nodules, compared to Ctrl, Sr1, Sr2, and Sr3.

CONCLUSION

Periodontal ligament cells responded to Sr4 with increased cellular proliferation and osteogenic behavior in vitro.

Effect of EMD on the orthodontically induced root resorption repair process in rats

BACKGROUND

While different levels of root resorption may occur in orthodontic treatment, several preventive approaches have been reported. Nevertheless, little is known about the effect of enamel matrix derivative (EMD) on root repair during orthodontic tooth movement.

OBJECTIVE

To evaluate the effect of EMD on root resorption repair following the application of orthodontic force.

MATERIALS AND METHODS

A force of 100 g was exerted for 14 days on the left maxillary first molars of twenty 10-week-old Sprague-Dawley rats divided into the EMD and control groups (n = 10 per group). In the EMD group, repeatedly injection of Emdogain® was administered after the appliance was removed, while phosphate-buffered saline was administered in the control group. In vivo microcomputed tomography (CT), haematoxylin and eosin (H&E) staining, and immunohistochemistry were then used to evaluate the effect of EMD on the process of root repair.

RESULTS

In the EMD group, the observed decrease in root resorption crater volume and increase in both the bone volume fraction and trabecular thickness were significantly greater than those in the control group. H&E staining showed that the periodontal fibres were relatively regular in arrangement and that the surface of the cementum was smooth in the EMD group. Immunohistochemical analysis showed higher bone morphogenetic protein 2 (BMP-2) and bone sialoprotein (BSP) expression levels in the EMD group than in the control group. In addition, the osteoprotegerin (OPG) and receptor activator of NF-κB ligand (RANKL) expression levels were similar in both groups.

CONCLUSION

EMD enhanced the repair process following orthodontically induced root resorption in rats.

Biofunctionalization of porcine-derived collagen matrix using enamel matrix derivative and platelet-rich fibrin: influence on mature endothelial cell characteristics in vitro

OBJECTIVES

The present study evaluated the effect of an enamel matrix derivative (EMD) and platelet-rich fibrin (PRF)-modified porcine-derived collagen matrix (PDCM) on human umbilical vein endothelial cells (HUVEC) in vitro.

MATERIALS AND METHODS

PDCM (mucoderm®) was prepared to 6 mm (±0.1 mm) diameter discs. PDCM samples were incubated with either EMD, PRF, or control solutions for 100 min at 4 °C before the experiments. Cell-inducing properties of test materials on HUVEC cells were tested with cell proliferation assays (MTT, PrestoBlue®), a cytotoxicity assay (ToxiLight®), a Boyden chamber migration assay, and a cell attachment assay. Scanning electron microscopy (SEM) imaging was performed to determine the surface and the architecture of the modified matrices.

RESULTS

Cell proliferation was elevated in the EMD and PRF groups compared with control (p each ≤0.046). PRF modification increased HUVEC migration ability by 8-fold compared with both control and EMD groups (p each <0.001). Both treatments significantly promoted the cell attachment of HUVEC to PDCM, as assessed by direct cell counts on the matrices (p each <0.001).

CONCLUSIONS

HUVEC cell characteristics were overall improved by EMD- and PRF- modified PDCM. Adsorbed bioactive molecules to the PDCM surface may have contributed to a more preferable environment to surrounding cells.

CLINICAL RELEVANCE

The results may give evidence that PDCM modification with EMD or PRF, respectively, might be a useful approach to improve clinical outcomes, to prevent inflammatory reactions and wound-healing disturbances, and to expand the clinical application area of PDCM.

Effectiveness of enamel matrix derivative on the clinical and microbiological outcomes following surgical regenerative treatment of peri-implantitis. A randomized controlled trial

OBJECTIVE

This randomized clinical trial aimed at comparing radiological, clinical and microbial effects of surgical treatment of peri-implantitis alone or in combination with enamel matrix derivative (EMD).

METHODS

Twenty-six subjects were treated with open flap debridement and decontamination of the implant surfaces with gauze and saline preceding adjunctive EMD or no EMD. Bone level (BL) change was primary outcome and secondary outcomes were changes in pocket depth (PD), plaque, pus, bleeding and the microbiota of the peri-implant biofilm analyzed by the Human Oral Microbe Identification Microarray over a time period of 12 months.

RESULTS

In multivariate modelling, increased marginal BL at implant site was significantly associated with EMD, the number of osseous walls in the peri-implant bone defect and a Gram+/aerobic microbial flora, whereas reduced BL was associated with a Gram-/anaerobic microbial flora and presence of bleeding and pus, with a cross-validated predictive capacity (Q(2) ) of 36.4%. Similar, but statistically non-significant, trends were seen for BL, PD, plaque, pus and bleeding in univariate analysis.

CONCLUSION

Adjunctive EMD to surgical treatment of peri-implantitis was associated with prevalence of Gram+/aerobic bacteria during the follow-up period and increased marginal BL 12 months after treatment.

Twenty years of enamel matrix derivative: the past, the present and the future

BACGROUND

On June 5th, 2015 at Europerio 8, a group of leading experts were gathered to discuss what has now been 20 years of documented evidence supporting the clinical use of enamel matrix derivative (EMD). Original experiments led by Lars Hammarström demonstrated that enamel matrix proteins could serve as key regenerative proteins capable of promoting periodontal regeneration including new cementum, with functionally oriented inserting new periodontal ligament fibres, and new alveolar bone formation. This pioneering work and vision by Lars Hammarström has paved the way to an enormous amount of publications related to its biological basis and clinical use. Twenty years later, it is clear that all these studies have greatly contributed to our understanding of how biologics can act as mediators for periodontal regeneration and have provided additional clinical means to support tissue regeneration of the periodontium.

AIMS

This review article aims to: (1) provide the biological background necessary to understand the rational for the use of EMD for periodontal regeneration, (2) present animal and human histological evidence of periodontal regeneration following EMD application, (3) provide clinically relevant indications for the use of EMD and (4) discuss future avenues of research including key early findings leading to the development of Osteogain, a new carrier system for EMD specifically developed with better protein adsorption to bone grafting materials.

Influence of enamel matrix derivative on healing of root surfaces after bonding treatment and intentional replantation of vertically fractured roots

BACKGROUND/AIM

The objectives of this study were to histopathologically evaluate cementum regeneration on root surfaces when an enamel matrix derivative (EMD) was used to bond a vertically fractured root and to evaluate the effectiveness of EMD in inhibiting root resorption.

MATERIAL AND METHODS

A total of 40 roots from 24 maxillary premolars in beagles were used. The root was vertically fractured using a chisel and mallet. Super-Bond was then used to bond the fractured root. In the experimental group, the root surface was treated with ethylenediaminetetraacetic acid and an EMD. The control group received no treatment. The root was then replanted in its original location. Histopathological observation and measurement using image-analyzing software were carried out after 8 weeks.

RESULTS

In the experimental group, shallow resorption cavities developed on the root planed surfaces with new acellular cementum appearing over them. In the control group, no new cementum was seen on the planed surfaces, and there was connective tissue joining the roots. In some of the samples, resorption and multinucleated giant cells were seen. The experimental group showed a significantly larger volume of cementum formation (P < 0.001), and the volume of root resorption was significantly smaller (P = 0.004).

CONCLUSION

When bonding and replanting tooth roots after a vertical fracture, the application of EMD was effective in regenerating cementum on root surfaces from which periodontal ligament had been lost in the area around the fracture line and in reducing the incidence of root resorption.

Osteogain improves osteoblast adhesion, proliferation and differentiation on a bovine-derived natural bone mineral

BACKGROUND

The use of enamel matrix derivative (EMD) has been shown to facilitate periodontal regeneration by histologically resulting in formation of cementum, periodontal ligament and bone. Recently, a new liquid carrier system for EMD has been introduced with better physicochemical properties specifically designed for bone graft mixing (Osteogain). The aim of this study was to investigate the combination of Osteogain with a bovine-derived natural bone mineral (NBM) on osteoblast migration, adhesion, proliferation and differentiation.

MATERIALS AND METHODS

Undifferentiated mouse ST2 stromal bone marrow cells were seeded onto 1)NBM particles alone or 2)NBM + Osteogain. Samples were compared for cell migration at 8 h, cell adhesion at 4 h, cell proliferation at 1, 3 and 5 days and real-time PCR at 3 and 14 days for genes encoding runt-related transcription factor 2 (Runx2), collagen1alpha2 (COL1a2), alkaline phosphatase (ALP) and osteocalcin (OCN). Furthermore, alizarin red staining was utilized to investigate the mineralization at 14 days.

RESULTS

Osteogain significantly upregulated cell adhesion over twofold onto NBM particles and promoted cell proliferation at 3 and 5 days after seeding. Furthermore, the combination of NBM with Osteogain significantly upregulated genes encoding Runx2, ALP, COL1a2 and OCN (from 1.5- to 3-fold) and increased alizarin red staining over 3 fold at 14 days when compared to NBM particles alone.

CONCLUSION

Pre-coating Osteogain onto NBM bone grafting particles significantly increased cell adhesion, proliferation and differentiation of osteoblasts in vitro. Future animal studies are now necessary to further investigate the regenerative potential of Osteogain in combination with a bone grafting material prior to clinical use for bone regeneration.

Effect of tyrosine-rich amelogenin peptide on behavior and differentiation of endothelial cells

Background

Enamel matrix derivative (EMD) is an effective biomaterial for periodontal tissue regeneration and might stimulate angiogenesis. Tyrosine-rich amelogenin peptide (TRAP) is present in EMD and is thought to contribute in its biological activity. In the present study, we investigated the effect of chemically synthesized TRAP on proliferation, migration, angiogenic structure formation, and differentiation of human umbilical vein endothelial cells (HUVECs) in vitro.

Material and methods

The effects of TRAP isolated from EMD and chemically synthesized TRAP on proliferation/viability, migration, and angiogenic structure formation were investigated. Expression of angiopoietin-2 (ang-2), von Willebrand factor (vWF), E-selectin, intracellular adhesion molecules 1 (ICAM-1), vascular endothelial growth factor (VEGF) receptors FMS-like tyrosine kinase 1 (FLT-1), and kinase insert domain receptor (KDR) was measured on both messenger RNA (mRNA) and protein levels.

Results

The proliferation/viability of HUVECs was inhibited by TRAP at concentration of 100 μg/ml and slightly stimulated by EMD at similar concentration. Both EMD and TRAP stimulated endothelial cell migration in microchemotaxis chamber. The effect of both TRAP preparations on the migration was significantly higher than that of EMD. All substances stimulated formation of angiogenic structure in vitro. The expression of ICAM-1, E-selectin, FLT-1, KDR, and vWF was significantly increased by both TRAP and EMD at a concentration 50 μg/ml. The expression of ang-2 was not affected by TRAP but was significantly increased by EMD.

Conclusion

Our in vitro study shows that TRAP confer the most effects of EMD on the endothelial cells.

Clinical relevance

TRAP might be used as a basis for development of new approaches for periodontal regeneration.

Enamel Matrix Derivative Promotes Healing of a Surgical Wound in the Rat Oral Mucosa

BACKGROUND

Enamel matrix proteins (EMPs) play a role in enamel formation and the development of the periodontium. Sporadic clinical observations of periodontal regeneration treatments with enamel matrix derivative (EMD), a commercial formulation of EMPs, suggest that it also promotes post-surgical healing of soft tissues. In vitro studies showed that EMD stimulates various cellular effects, which could potentially enhance wound healing. This study examines the in vivo effects of EMD on healing of an oral mucosa surgical wound in rats.

METHODS

A bilateral oral mucosa wound was created via a crestal incision in the anterior edentulous maxilla of Sprague-Dawley rats. Full-thickness flaps were raised, and, after suturing, EMD was injected underneath the soft tissues on one side, whereas the EMD vehicle was injected in the contralateral side. Animals were sacrificed after 5 or 9 days, and the wound area was subjected to histologic and immunohistochemical analysis of the epithelial gap, number of macrophages, blood vessels, proliferating cells, and collagen content in the connective tissue (CT). Gene expression analysis was also conducted 2 days post-surgery.

RESULTS

EMD had no effect on the epithelial gap of the wound. On both days 5 and 9, EMD treatment increased significantly the number of blood vessels and the collagen content. EMD also enhanced (by 20% to 40%) the expression of transforming growth factors β1 and β2, vascular endothelial growth factor, interleukin-1β, matrix metalloproteinase-1, versican, and fibronectin.

CONCLUSION

EMD improves oral mucosa incisional wound healing by promoting formation of blood vessels and collagen fibers in CT.