Enamel Matrix Derivative Research Articles

Various Coated Barrier Membranes for Better Guided Bone Regeneration: A Review

A good barrier membrane is one of the important factors for effective guided bone/tissue regeneration (GBR/GTR) in the case of periodontal bone defects. Several methods are being discussed to overcome and improve the shortcomings of commercially available membranes. One of the methods is to coat the membrane with bioactive materials. In this study, 41 studies related to coated membranes for GBR/GTR published in the last 5 years were reviewed. These studies reported coating the membrane with various bioactive materials through different techniques to improve osteogenesis, antimicrobial properties, and physical/mechanical properties. The reported studies have been classified and discussed based on the purpose of coating. The goal of the most actively studied research on coating or surface modification of membranes is to improve new bone formation. For this purpose, calcium phosphate, bioactive glass, polydopamine, osteoinduced drugs, chitosan, platelet-rich fibrin, enamel matrix derivatives, amelotin, hyaluronic acid, tantalum, and copper were used as membrane coating materials. The paradigm of barrier membranes is changing from only inert (or biocompatible) physical barriers to bioactive osteo-immunomodulatory for effective guided bone and tissue regeneration. However, there is a limitation that there exists only a few clinical studies on humans to date. Efforts are needed to implement the use of coated membranes from the laboratory bench to the dental chair unit. Further clinical studies are needed in the patients’ group for long-term follow-up to confirm the effect of various coating materials.

Surgical management of peri‐implantitis: A narrative review

AbstractBackground and aimPeri‐implantitis is a biological complication characterised by inflammation and progressive bone loss around a dental implant. The definitions of peri‐implantitis show inconsistency, making diagnosis and treatment regimen incomparable. The 2017 World Workshop on the Classification of Periodontal and Peri‐implant diseases rationalised the definition of peri‐implantitis. This narrative review aims to provide an overview of the surgical management of peri‐implantitis and critically evaluate current evidence published after the 2017 World Workshop.MethodAn electronic literature search of MEDLINE, EMBASE and The Cochrane Library was performed, limited to prospective cohort studies and randomised controlled trials. Outcome measures were: bleeding on probing, suppuration on probing, pocket probing depth and radiographic marginal bone level.ResultsNine randomised controlled trials met the inclusion criteria. None of the studies used the 2017 World Workshop definition for peri‐implantitis. Seven studies were regenerative in nature (four xenografts, two alloplasts and one enamel matrix derivative). Two studies were non‐regenerative. Aggregation of outcome data was not possible due to significant heterogeneities for treatment protocols and volunteer inclusion criteria. All interventions led to a reduction in bleeding on probing and pocket probing depths. Gain in radiographic bone height was greater for regenerative studies.ConclusionSurgical interventions for peri‐implantitis appear effective at reducing clinical signs of inflammation in the short term. There is no reliable evidence to determine which methods are most effective. Universal adoption of the 2017 World Workshop definition of peri‐implantitis by future studies is a prerequisite for the development of standardised evidence‐based protocols for the treatment of peri‐implantitis.

Use of Enamel Matrix Derivative in Minimally Invasive/Flapless Approaches: A Systematic Review with Meta-Analysis.

The aim of the present systematic review with meta-analysis was to investigate the clinical effectiveness of EMD (enamel matrix derivative) using a minimally invasive surgical technique (MIST) or flapless approach for the treatment of severe periodontal probing depths. A systematic review of the literature including searches in PubMed/Medline, Cochrane Library, Google Scholar, and Grey Literature databases as well as manual searches was performed on September 1st, 2021. Studies utilising EMD in a non-surgical or minimally invasive approach were included. The eligibility criteria comprised randomised controlled trials (RCTs) comparing minimally-invasive/flapless approaches with/without EMD for the treatment of probing depths >5 mm. From 1525 initial articles, 7 RCTs were included and 12 case series discussed. Three studies investigated a MIST approach, whereas 3 studies utilised a flapless approach. One study compared EMD with either a MIST or a flapless approach. The RCTs included ranged from 19-49 patients with at least 6 months of follow-up. While 5 of the studies included smokers, patients smoking >20 cigarettes/day were excluded from the study. The meta-analysis revealed that EMD with MIST improved recession coverage (REC) and bone fill (BF) when compared to MIST without EMD. However, no difference in CAL or PD was observed between MIST + EMD vs MIST without EMD. No statistically significant advantage was found for employing the EMD via the flapless approach. Implementing EMD in MIST procedures displayed statistically significant improvement in REC and BF when compared to MIST alone. These findings suggest that MIST in combination with EMD led to improved clinical outcomes while EMD employed in nonsurgical flapless therapy yielded no clinical benefits when compared to nonsurgical therapy alone without EMD. More research is needed to substantiate these findings.

The phosphorylation of serine55 in enamelin is essential for murine amelogenesis

Amelogenesis imperfecta (AI) is an inherited developmental enamel defect affecting tooth masticatory function, esthetic appearance, and the well-being of patients. As one of the major enamel matrix proteins (EMPs), enamelin (ENAM) has three serines located in Ser-x-Glu (S-x-E) motifs, which are potential phosphorylation sites for the Golgi casein kinase FAM20C. Defects in FAM20C have similarly been associated with AI. In our previous study of EnamRgsc514 mice, the Glu57 in the S55-X56-E57 motif was mutated into Gly, which was expected to cause a phosphorylation failure of Ser55 because Ser55 cannot be recognized by FAM20C. The severe enamel defects in ENAMRgsc514 mice reminiscent of Enam-knockout mouse enamel suggested a potentially important role of Ser55 phosphorylation in ENAM function. However, the enamel defects and ENAM dysfunction may also be attributed to distinct physicochemical differences between Glu57 and Gly57. To clarify the significance of Ser55 phosphorylation to ENAM function, we generated two lines of Enam knock-in mice using CRISPR-Cas9 method to eliminate or mimic the phosphorylation state of Ser55 by substituting it with Ala55 or Asp55 (designated as S55A or S55D), respectively. The teeth of 6-day or 4-week-old mice were subjected to histology, micro-CT, SEM, TEM, immunohistochemistry, and mass spectrometry analyses to characterize the morphological, microstructural and proteomic changes in ameloblasts, enamel matrix and enamel rods. Our results showed that the enamel formation and EMP expression in S55D heterozygotes (Het) were less disturbed than those in S55A heterozygotes, while both homozygotes (Homo) had no mature enamel formation. Proteomic analysis revealed alterations of enamel matrix biosynthetic and mineralization processes in S55A Hets. Our present findings indicate that Asp55 substitution partially mimics the phosphorylation state of Ser55 in ENAM. Ser55 phosphorylation is essential for ENAM function during amelogenesis.

The influence of IGF-I and Emdogain on the behavior of dental epithelial cells in a three-dimensional scaffold model

Aim: Tooth decay and associated periodontal disease remain the most common chronic diseases in current society. In the future, individually tailored, more effective therapeutic treatment options could be provided through the application of tissue engineering and regenerative medicine and dentistry (TERMD) approaches. A relevant finding is the potential of both dental mesenchymal and dental epithelial cells to regenerate mineralized dentin and enamel tissues, respectively.Materials and Methods: In the current study, a multi-layered, bioengineered tooth bud model was assembled by combining human dental mesenchymal (hDM) and porcine dental epithelial cells (pDE). The hDM cells were seeded onto poly(epsilon-caprolactone)/ poly (lactide-co-glycolide) (PCL/PLGA) wet electro-spun scaffolds overlayed with confluent pDE cell sheet harvested from thermo-reversible tissue culture plates. The so-formed multi-layered bioengineered tooth bud was then used to study the mineralization potential of the dental cells in in vitro culture. It was hypothesized that the addition of the in media soluble factors Insulin-like growth factor 1 (IGF-I) and the extracellular matrix derivate Emdogain (EMD) would result in enhanced differentiation and mineralized dental tissue formation. Scanning Electron morphological observation was used to characterize scaffolds porosity. Histological and immunofluorescent analyses confirmed the localization of hDM cells inside the scaffold, an intact pDE cell sheet, and the presence of beta-integrin 1-positive cell-cell junctions connecting the two.Results: Scanning Electron Microscopy showed that EMD, in particular, enhanced the mineralization potential of pDE cells. qRT-PCR analyses showed that both EMD and IGF-1 significantly enhanced the expression of Ameloblastin (AMBN), reflecting pDE cell differentiation.Conclusion: In conclusion, these results proved the hypothesis that both EMD and IGF-1 should be considered for their utility in preclinical dental tissue engineering approaches.

Enamel Matrix Derivative (Emdogain) for Wound Healing and Bone Regeneration: A Short-Review

Emdogain® is a unique gel containing an enamel matrix derivative of protein origin. This mixture of natural proteins can induce biological processes; that usually take place during development/regeneration of periodontium by stimulating certain cells involved in the healing process of soft/hard tissues. This agent is intended to improve the quality of patient’s life by reducing pain, swelling and systemic inflammation after completing treatment procedures. Therefore, the aim of this short-review was to understand the rationale behind the use of Emdogain® as a smart biomaterial for periodontal and peri-implant regenerations; and further to provide a clinical perspective for Oral Surgeons and Periodontists in Libya. Keywords: Enamel Matrix Derivative (Emdogain®); Implantology; Periodontology; Wound Healing; Regeneration.

Effects of Early Life Adversity on Tooth Enamel Formation.

In a systemic effort to survive environmental stress, organ systems fluctuate and adapt to overcome external pressures. The evolutionary drive back toward homeostasis makes it difficult to determine if an organism experienced a toxic exposure to stress, especially in early prenatal and neonatal periods of development. Previous studies indicate that primary human teeth may provide historical records of experiences related to stressors during that early time window. To assess the molecular effects of early life adversity on enamel formation, we used a limited bedding and nesting (LBN) mouse model of early life adversity (ELA) to assess changes in the enamel organ gene expression and enamel matrix mineralization. On average, postnatal day 12 (P12) ELA mice weighed significantly less than the controls. When adjusted for animal weight, ELA molar enamel volume was reduced as compared with the controls, and the relative mineral density of molar enamel was significantly increased. There were no obvious changes in enamel matrix crystal morphology or structure in ELA as compared with the control mouse enamel. RNAseq showed extracellular matrix organization to be the most significantly affected GO and reactome pathways, whereas butanote metabolism was the most significantly altered KEGG pathway. Transcripts expressing the enamel matrix proteins amelogenin (Amelx) and enamelin (Enam) were among the top 4 most differentially expressed genes. When evaluating molecular mechanisms for the changes in gene expression in ELA enamel organs, we found significantly increased expression of Dlx3, while transcripts for clock genes Per1 and Nrd1 were downregulated. These findings support the possibility that the developing enamel organ is sensitive to the pressures of early life adversity and produces molecular and structural biomarkers reflecting these challenges.

Evaluation of the Effects of Enamel Matrix Protein Derivatives on Clinical Attachment Gain in Periodontal Defects and on Proliferation and Differentiation of Periodontal Ligament Fibroblasts <i>In Vitro</i>: A Double-blind Study

Evaluation of the Effects of Enamel Matrix Protein Derivatives on Clinical Attachment Gain in Periodontal Defects and on Proliferation and Differentiation of Periodontal Ligament Fibroblasts <i>In Vitro</i>: A Double-blind Study

Loss of BMP2 and BMP4 Signaling in the Dental Epithelium Causes Defective Enamel Maturation and Aberrant Development of Ameloblasts.

BMP signaling is crucial for differentiation of secretory ameloblasts, the cells that secrete enamel matrix. However, whether BMP signaling is required for differentiation of maturation-stage ameloblasts (MA), which are instrumental for enamel maturation into hard tissue, is hitherto unknown. To address this, we used an in vivo genetic approach which revealed that combined deactivation of the Bmp2 and Bmp4 genes in the murine dental epithelium causes development of dysmorphic and dysfunctional MA. These fail to exhibit a ruffled apical plasma membrane and to reabsorb enamel matrix proteins, leading to enamel defects mimicking hypomaturation amelogenesis imperfecta. Furthermore, subsets of mutant MA underwent pathological single or collective cell migration away from the ameloblast layer, forming cysts and/or exuberant tumor-like and gland-like structures. Massive apoptosis in the adjacent stratum intermedium and the abnormal cell-cell contacts and cell-matrix adhesion of MA may contribute to this aberrant behavior. The mutant MA also exhibited severely diminished tissue non-specific alkaline phosphatase activity, revealing that this enzyme’s activity in MA crucially depends on BMP2 and BMP4 inputs. Our findings show that combined BMP2 and BMP4 signaling is crucial for survival of the stratum intermedium and for proper development and function of MA to ensure normal enamel maturation.

Effect of an enamel matrix derivative (Emdogain) on the microhardness and chemical composition of human root dentin: an in vitro study

The advantage of using an Enamel matrix derivative EMD Emdogain as an intracanal medication could be a manner to strength the tooth structure, improving the physical and chemical properties of dentin. We tested, in vitro, the effect of Emdogain on the surface microhardness and chemical composition of root dentin. Ten human teeth were used to produce dentin specimens originated from the canal walls (n = 30) that remained in contact to Emdogain gel for 90 days. Baseline and 90-days after Emdogain treatment measurements were performed using Fourier Transform Infrared Spectroscopy (ATR/FTIR), Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS) and Knoop indenters. The use of EMD (Emdogain) for 90 days in contact with human root canal dentin specimens did not alter the microhardness and morphology of dentin. The elemental structure of dentin was altered because there was a reduction in carbonate content.

The effect of melatonin on the mouse ameloblast-lineage cell line ALCs

Melatonin plays a critical role in promoting the proliferation of osteoblasts and the growth and development of dental papilla cells. However, the effect and mechanism of melatonin on the growth and development of ALCs still need to be explored. CCK8 assay was used for the evaluation of cell numbers. qRT-PCR was used to identify the differentially expressed genes in ALCs after melatonin treatment. The number and morphology of ALCs were investigated by confocal microscopy. Alkaline phosphatase assay and Alizarin red S staining were used for measuring mineralization. Then, we focused on observing the crucial factors of the signaling pathway by RNA-seq and qRT-PCR. Melatonin limited the cell number of ALCs in a dose-dependent manner and promoted the production of actin fibers. A high concentration of melatonin significantly promoted the mRNA levels of enamel matrix proteins and the formation of mineralized nodules. RNA-seq data showed that Wnt signaling pathway may be involved in the differentiation of ALCs under the influence of melatonin. This study suggests that melatonin plays a regulatory role in the cell number, differentiation, and mineralization of the ALCs, and then shows the relationship between the Wnt signaling pathway with the ALCs under melatonin.

Does the subepithelial connective tissue graft in conjunction with a coronally advanced flap remain as the gold standard therapy for the treatment of single gingival recession defects? A systematic review and network meta-analysis.

The aim of this systematic review and network meta-analysis (NMA) was to assess the efficacy of a bilaminar root coverage technique consisting of the combination of an autogenous subepithelial connective tissue graft (SCTG) and a coronally advanced flap (CAF) compared with the five most indicated alternative approaches for the treatment of single gingival recession defects (GRD). The protocol of this PRISMA 2020-compliant systematic review was registered in PROSPERO (CRD42020221362). Three electronic databases were searched up to September 30, 2021 to identify randomized controlled trials that involved the treatment of single GRD without interproximal tissue loss via root coverage procedures. A frequentist NMA was conducted for complete root coverage (CRC), mean root coverage (MRC), and keratinized tissue width (KTW) changes. A total of 38 studies reporting on 830 patients and 1,265 GRD were included. SCTG + CAF was ranked as the most efficient treatment approach for MRC, CRC, and KTW gain at 6 and 12 months after surgery, except for MRC at the 12-month follow-up where enamel matrix derivative plus CAF exhibited superior results. SCTG + CAF can be considered the gold standard for the treatment of single GRD.

Enamel Matrix Derivative Decreases Pyroptosis-Related Genes in Macrophages

Background: Pyroptosis is a caspase-dependent catabolic process relevant to periodontal disorders for which inflammation is central to the pathophysiology of the disease. Although enamel matrix derivative (EMD) has been applied to support periodontal regeneration, its capacity to modulate the expression of pyroptosis-related genes remains unknown. Considering EMD has anti-inflammatory properties and pyroptosis is linked to the activation of the inflammasome in chronic periodontitis, the question arises whether EMD could reduce pyroptosis signalling. Methods: To answer this question, primary macrophages obtained from murine bone marrow and RAW 264.7 macrophages were primed with EMD before being challenged by lipopolysaccharide (LPS). Cells were then analysed for pyroptosis-signalling components by gene expression analyses, interleukin-1β (IL-1β) immunoassay, and the detection of caspase-1 (CAS1). The release of mitochondrial reactive oxygen species (ROS) was also detected. Results: We report here that EMD, like the inflammasome (NLRP3) and CAS1 specific inhibitors—MCC950 and Ac-YVAD-cmk, respectively—lowered the LPS-induced expression of NLRP3 in primary macrophages (EMD: p = 0.0232; MCC950: p = 0.0426; Ac-YVAD-cmk: p = 0.0317). EMD further reduced the LPS-induced expression of NLRP3 in RAW 264.7 cells (p = 0.0043). There was also a reduction in CAS1 and IL-1β in RAW 264.7 macrophages on the transcriptional level (p = 0.0598; p = 0.0283; respectively), in IL-1β protein release (p = 0.0313), and CAS1 activity. Consistently, EMD, like MCC950 and Ac-YVAD-cmk, diminished the ROS release in activated RAW 264.7 cells. In ST2 murine mesenchymal cells, EMD could not be tested because LPS, saliva, and IL-1β + TNF-α failed to provoke pyroptosis signalling. Conclusion: These findings suggest that EMD is capable of dampening the expression of pyroptosis-related genes in macrophages.

The Effect of an Alloplastic Bone Substitute and Enamel Matrix Derivative on the Preservation of Single Anterior Extraction Sockets: A Histologic Study in Humans

This study was designed to assess the effect of enamel matrix derivative (Emdogain, Straumann) and alloplastic bone substitute (BoneCeramic, Straumann) on new bone formation in postextraction alveolar sockets. Twenty-one patients requiring anterior single-tooth extractions and subsequent implant placement were recruited and randomly assigned to one of three treatment groups. Postextraction sockets were filled with either an alloplastic bone substitute (BoneCeramic [BC]), BC combined with Emdogain (EMD+BC), or left to heal spontaneously (SO). Histologic and histomorphometric analyses of the results were performed at 6 months postextraction. A significant increase in the percentage of new bone tissue area was found in EMD+BC compared to SO and BC groups. These findings demonstrate that compared with BC or SO, EMD+BC allowed for better formation of new bone in postextraction sockets after 6 months of healing.

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.

Overview of the Effect of Different Regenerative Materials in Class II Furcation Defects in Periodontal Patients.

The aim of this review was to give an overview of the outcomes of the use of different regenerative materials to treat molars with class II furcation defects in patients with periodontitis in comparison with open flap debridement (OFD). A search of five databases (PubMed-Medline, Embase, Cochrane, Scopus and Web of Science) was conducted up to and including January 2022. According to the PICOS guidelines, only randomized control trials (S) considering periodontal patients with at least one molar with a class II furcation involvement (P) treated with regenerative materials (I) in comparison to OFD as control treatment (C) and a minimum follow-up period of 6 months were included. Vertical clinical attachment level (VCAL) was considered as the primary outcome (O), while horizontal clinical attachment level (HCAL), horizontal probing depth (HPD) and vertical probing depth (VPD) were considered as secondary outcomes. The search through the databases initially identified 1315 articles. Only 25 of them met the eligibility criteria and were included. The studies were grouped in four macro-categories according to the material used: absorbable and non-absorbable membranes, blood derivatives and a combination of different materials. The greater part of the included studies reported a statistically significant difference in using regenerative materials when compared to OFD. The blood derivatives groups reported a range of mean changes in VCAL of 0.86–4.6 mm, absorbable membrane groups reported −0.6–3.75 mm, non-absorbable membranes groups reported −2.47–4.1 mm, multiple materials groups reported −1.5–4.87 mm and enamel matrix derivatives reported a mean change in VCAL of 1.45 mm. OFD showed a range of mean VCAL changes of −1.86–2.81 mm. Although no statistical analysis was performed, the use of regenerative materials may be considered moderately beneficial in the treatment of molars with grade II furcation involvement. However, the substantial heterogeneity in the protocols’ design does not allow us to draw definitive conclusions. In addition, low levels of evidence for morbidity and patient-centered outcomes were reported.

Modified minimally invasive surgical technique in human intrabony defects with or without regenerative materials-10-year follow-up of a randomized clinical trial: Tooth retention, periodontitis recurrence, and costs.

The modified minimally invasive surgical technique (M-MIST) optimizes wound stability in the treatment of intrabony defects. Short-term observations show similar results as with flap alone or adjunctive regenerative materials. This study aims to compare the stability of the long-term outcomes, complication-free survival, and costs of the three treatment options. Forty-five intrabony defects in 45 patients were randomized to M-MIST alone (N= 15), combined with enamel matrix derivative (M-MIST + EMD, N= 15), or EMD plus bone-mineral-derived xenograph (M-MIST + EMD + BMDX, N= 15). Supportive periodontal care (SPC) and necessary re-treatment were provided for 10 years. Three subjects were lost to follow-up. Clinical attachment level differences between 1 and 10 years were -0.1± 0.7 mm for M-MIST, -0.1± 0.8 mm for M-MIST + EMD, and -0.3± 0.6 mm for M-MIST + EMD + BMDX (p> .05 for within- and between-group differences). Four episodes of recurrence occurred in the M-MIST group, four in the M-MIST + EMD group, and five in the M-MIST + EMD + BMDX group. No significant differences in complication-free survival were observed between the three groups (p= .47). Complication-free survival was 7.46 years (95% confidence interval: 7.05-7.87) for the whole population. The M-MIST + EMD + BMDX group lost one treated tooth. Data indicated no significant inter-group difference of the total cost of recurrence over 10 years. When the baseline cost of treatment was considered, the total cost was lower for M-MIST alone. Teeth with deep pockets associated with intrabony defects can be successfully maintained over the long term with either M-MIST alone or by adding a regenerative material in the context of a careful SPC programme. M-MIST alone provided similar short- and long-term benefits as regeneration, at a lower cost. These findings need to be confirmed in larger, independent studies.

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.

Surgical therapy of peri-implantitis with adjunctive hydroxyapatite and enamel matrix derivative: a 1-year retrospective case series

This case series retrospectively investigated the one-year surgical outcome of regenerative peri-implantitis therapy using a hydroxyapatite (HA) bone substitute material in combination with enamel matrix derivate (EMD) and collagen membrane for guided bone regeneration (GBR). Data-sheets of patients were screened to detect patients who received identical regenerative peri-implantitis-therapy with surface decontamination and GBR applying HA, EMD and a collagen membrane under broad-spectrum antibiotic regime. For inclusion, information on pre- and postoperative clinical and radiographic parameters (probing pocket depth (PPD), bleeding on probing (BOP), suppuration (SUPP) and the radiological bone level (RBL)) had to be available for statistical analysis. Data of a total of 11 patients (20 implants) were extracted out of 202 (336). All implants were still in function after one year. Bone defects decreased by an average of 1.3 mm mesially and 0.9 mm distally, respectively. Mean PPD was reduced from 4.9 mm to 2.7 mm. BOP decreased from 90% to 20%. Suppuration decreased from 65% to 0%. Based on the success criteria applied, 15 of the 20 (75%) implants included were considered as successfully treated after 1 year. Regenerative peri-implantitis therapy according to the presented concept showed promising clinical and radiographic outcomes after one year. To estimate the beneficial effects of the combined use of HA, EMD and collagen membranes, further long-term investigations with a control group are needed.
 Accepted for publication: January 7, 2022
 Published online: January 12, 2022

Surgical therapy of peri-implantitis with adjunctive hydroxyapatite and enamel matrix derivative: a 1-year retrospective case series.

This case series retrospectively investigated the one-year surgical outcome of regenerative peri-implantitis therapy using a hydroxyapatite (HA) bone substitute material in combination with enamel matrix derivate (EMD) and collagen membrane for guided bone regeneration (GBR). Data-sheets of patients were screened to detect patients who received identical regenerative peri implantitis-therapy with surface decontamination and GBR applying HA, EMD and a collagen membrane under broad- spectrum antibiotic regime. For inclusion, information on pre- and postoperative clinical and radiographic parameters (probing pocket depth (PPD), bleeding on probing (BOP), suppuration (SUPP) and the radiological bone level (RBL)) had to be available for statistical analysis. Data of a total of 11 patients (20 implants) were extracted out of 202 (336). All implants were still in function after one year. Bone defects decreased by an average of 1.3 mm mesially and 0.9 mm distally, respectively. Mean PPD was reduced from 4.9 mm to 2.7 mm. BOP decreased from 90% to 20%. Suppuration decreased from 65% to 0%. Based on the success criteria applied, 15 of the 20 (75%) implants included were considered as successfully treated after 1 year. Regenerative peri-implantitis therapy according to the presented concept showed promising clinical and radiographic outcomes after one year. To estimate the beneficial effects of the combined use of HA, EMD and collagen membranes, further long term investigations with a control group are needed.