Role of emdogain in periodontal therapyIntroduction:periodontitis represents an inflammatory disease initiated by bacterial biofilms and, if left untreated, is one of the major causes of tooth loss. The main goal of periodontal therapy is to stop periodontal disease progression and avoid tooth loss. After non surgical mechanical debridement and access flap surgery, wound healing occurs by repair mechanisms characterized by the formation of a junctional epithelium along the instrumented root surface. Therapeutic approaches to the treatment of periodontitis generally fall into two major categories: the ones designed to stop the progression of periodontal attachment loss, and the others designed to regenerate or reconstruct lost periodontal tissues. However, the ultimate goal of periodontal therapy is the regeneration of the tooth-supporting structures, including the root cementum, periodontal ligament, and alveolar bone that is lost because of periodontitis. Periodontal regeneration is defined as the reconstruction of lost or injured tissue so that the form and function of the lost structures are restored it should include regeneration of cementum, functionally aligned periodontal ligament, alveolar bone, and gingiva. Several treatment modalities, such as the use of different types of bone grafts, guided tissue regeneration (GTR), growth factors, or the application of enamel matrix protein derivative (EMD/Emdogain), have been employed with varying degrees of success to predictably accomplish this goal It has been suggested that EMD are involved in the formation of acellular extrinsic fiber cementum and may trigger the differentiation of progenitor cells into cementoblasts. Emdogain commercial product consists of a gel containing purified acidic extract from porcine enamel matrix containing the hydrophobic protein assembly of amelogenins, it is clinically used in periodontal regenerative surgery which appears to favour the formation of new attachment characterized by the presence of new acellular and/or cellular cementum with inserting collagen fibers and new alveolar bone. The proteins are solubilized in a neutral propylene glycol alginate vehicle for delivery to the surgical site. The propylene glycol alginate leaves the surgical site after the application allowing the amelogenin fraction to precipitate into an insoluble extracellular supra molecular aggregate. emdogain when applied to the root surface in conjunction with surgical periodontal therapy has been shown to promote periodontal regeneration. A recent Cochrane systematic review and clinical trials has shown that sites treated with enamel matrix-derived proteins displayed significant improvements in pocket depth reduction when compared with open flap debridement alone. A controlled clinical study further showed that OFD in combination with EMD led to a three times greater defect ?ll when compared to OFD alone. In study conducted by Tonetti et al indicated that regenerative periodontal surgery with EMD resulted in an additional bene?t in of CAL gains, PPD reductions and predictability of outcomes with respect to papilla preservation ?aps alone . Another series of experiments focused primarily on comparing the use of EMD to GTR using either non-resorbable or bioabsorbablemembranes found that the use of EMD or GTR led to substantially higher CAL gains and defect ?ll when compared to OFD alone for the treatment of single intrabonydefects. Studies had assessed the treatment of single intrabony defects following treatment with EMD, GTR or a combination of both. Comparable results were also reported indicating that, for treatment of single self-contained intrabony defects, the additional use of a barrier membrane in combination with EMD alone led to no additional improvements when compared to EMD alone, or to GTR alone.(13) .A systematic review and meta-analysis on 12 studies reporting on 434 patients found that the combination of bone grafting material with EMD led to statistically signi?cant better outcomes and the combination of some bone grafting materials with EMD seems to favour periodontal regeneration, while many other studies showed no additional bene?t when compared to bone grafting material alone or to EMD alone.Searching Methods:Search was conducted in electronic databases PubMed and Cochrane Library was conducted, using the following search term combination: ”(emdogain OR EMD OR enamel matrix derivative OR enamel matrix proteins) AND (periodontal therapy OR bone regeneration ).” Inclusion criteria A literature search was performed to identify meta-analysis, systematic reviews as well as randomized-controlled clinical trials (RCTs) in English language and listed in the electronic databases, PubMed or Cochrane Library, or were listed as reference in selected articles. The research was limited to articles that included the terms “clinical trial,” “review” and “meta-analysis.”.Results:Non surgical periodontal therapy :Two randomized, placebo controlled clinical studies have evaluated the effects of EMD as adjunct to non-surgical periodontal therapy (SRP) only. In both studies, EMD failed to show any bene?cial effect.Surgical treatment of intrabony defects :Data from controlled clinical studies have demonstrated that treatment of intrabonydefects with EMD has resulted in better clinical periodontal and radiographic parameters when compared to flap surgery alone. Split mouth, double blind, randomized controlled trial was done to compare the clinical effect of treatment of 2- or 3-wall intrabony defects with open flap debridement (OFD) alone or combined with EMD. After 6 months the result was a significant reduction in PPD for the EMD group from 6.42 ± 1.08 mm to 2.67 ± 1.15 mm and for the OFD group (from 6.08 ± 1.00 mm to 2.00 ± 0.95 mm). Also a significant gain in relative attachment level (RAL) was observed in EMD groups from 13.42 ± 1.88 mm to 10.75 ± 2.26 mm, and OFD groups from 12.42 ± 1.98 mm to 10.58 ± 2.23 mm. Gingival recession (GR) was higher in the EMD group from 1.08 ± 1.50 mm to 2.33 ± 1.43 mm than in the OFD group which was from 0.66 ± 1.15 mm to 1.16 ± 1.33 mm. Froum et al did a controlled clinical trial to clinically compare the 1-year results of the treatment of intraosseous defects with either (OFD) alone or in conjunction with the use of EMD with re-entry data of new bone fill. They found that EMD group was superior in average PD reduction which was 2.7 mm greater than with controls. The average CAL gains were 1.5 mm greater, and the average fill of osseous defect 2.4 mm greater with EMD than controls. The average percent of defect fill after adjusting for crestal bone loss was more than 3 times greater for EMD versus OFD treated sites. Long-term effect of EMD treatment was evaluated in 33 subjects that had a PD more than 6 and intrabony defect more than 4 and the mean value after 36 months there for clinical attachment level gain in test 2.2mm and 1.7 mm. The radiographic bone level continued to increase over the 36 months at the EMD treated sites up to 2.6 mm, while it remained close to the baseline level at the control sites. Ribeiro et al , failed to show any superior benefit for the use of EMD when compared to the minimally invasive surgical approach for the treatment of intrabony defects in single rooted teeth. Furthermore, Chambrone et al concluded that there were no significant difference when a compression of EMD to OFD was done in treating of 2 to 3 wall intrabony defects. When comparing GTR and EMD in treating intrabony defects, clinical trials failed to demonstrate superiority of one treatment modality over the other. A randomized, controlled, prospective clinical study was done to compare GTR to EMD for the treatment of intrabony defects in patients with chronic advanced periodontitis. The results was in 36 months after surgery, sites treated with GTR at 36 months demonstrated the mean gain in CAL were 2.0 ± 1.1 mm and mean reduction of PD 3.2 ± 1.1 mm when compared to baseline. Sites treated with EMD demonstrated a mean CAL gain of 2.4 ± 1.2 mm and a mean reduction in PD of 3.1 ± 1.4 mm at 36 months. The differences in PD reduction and CAL gain were statistically significant between the groups and for each time point compared to baseline. Prospective multicenter, randomized, controlled clinical trial compared the clinical outcomes of EMD versus placement of a bioabsorbable membrane in conjunction with guided tissue regeneration GTR. At 1 year, the EMD defects gained 3.1 ± 1.8 mm of CAL, versus 2.5 ± 1.9 mm for GTR defects. Probing depth reduction was 3.8 ± 1.5 mm and 3.3 ± 1.5 mm, respectively. In addition, all cases treated with GTR presented at least one surgical complication, mostly membrane exposure, while only 6% of EMD treated sites displayed complications. Sculean found that treatment of intrabony defects with EMD or GTR can be maintained up to eight years . Siciliano et al, showed clinical improvement of sites treated with GTR when compared to EMD. They compared the healing of deep, non-contained intrabony defects treated with either an EMD or guided tissue regeneration GTR after 12 months. The mean CAL gain at sites treated with GTR was significantly greater than that at sites treated with EMD (4.1 – 1.4 mm versus 2.4 – 2.2 mm, respectively). A combination technique including bovine porous bone mineral, EMD, and GTR results in better clinical resolution of intrabony defects than treatment with OFD. surgically reentered sites at 6 months revealed in the experimental group a significantly greater reduction in probing depth and moreattachment gain than the control sites.