Enamel matrix derivative induces matrix synthesis by cultured human periodontal fibroblast cells

Effects of Enamel Matrix Derivative on Bone-Related mRNA Expression in Human Periodontal Ligament Cells In Vitro

BACKGROUND

Enamel matrix derivative (EMD) has demonstrated the potential to stimulate periodontal regeneration with mineralized tissue formation. Molecular regulators of bone metabolism include osteoprotegrin (OPG), receptor activator of nuclear factor kappa B ligand (RANKL), cyclooxygenase 2 (COX2), and core binding factor alpha 1 (Cbfa1). The role of these regulatory molecules within the context of EMD stimulation of mineralized tissue formation is unknown. Therefore, the purpose of this investigation was to explore the effects of EMD on these bone-related molecules in human periodontal ligament (PDL) cells.

METHODS

Human PDL-cell cultures were treated with EMD (5 to 100 microg/ml) for 24 hours. Total RNA was isolated using phenolchloroform, and reverse transcription-polymerase chain reaction (RT-PCR) was performed using primers specific for OPG, RANKL, COX2, Cbfa1, and aldolase, with amplification in the exponential range for each molecule studied.

RESULTS

The results of this study show that there is a significant (P <0.05) increase in COX2 mRNA levels with EMD treatment, and no effects were noted on mRNA levels for Cbfa1. RANKL mRNA levels were significantly decreased (P <0.01) up to 50% with EMD treatment > or =25 microg/ml. OPG levels showed minimal effects with EMD treatment. However, the RANKL/OPG ratio showed a 40% to 55% reduction with EMD >or =25 microg/ml.

CONCLUSION

This study supports a role for EMD stimulation of mineralized tissue formation consistent with periodontal regeneration by modulating regulatory molecules critical to bone metabolism at the RNA level.

The effect of the amelogenin fraction of enamel matrix proteins on fibroblast-mediated collagen matrix reorganization

Enamel matrix proteins (EMP), extracted from developing porcine teeth, promote not only periodontal regeneration but also cutaneous wound healing presumably via the amelogenin fraction. Because it is unclear whether the effect of EMP can be ascribed to amelogenins, we compared EMP with recombinant amelogenin in the relaxed dermal equivalent (DE) in vitro model for early wound contraction. EMP and recombinant porcine amelogenin (rP172) at 1 mg/ml were incorporated into DEs composed of human dermal fibroblasts and a type I collagen matrix. The area reduction, as a measure of contraction, as well as fibroblast numbers and TGF-beta1 levels, were quantified over 7 days in culture in the presence of 10% foetal bovine serum. Both EMP and recombinant amelogenin increased contraction (p < 0.005) and fibroblast numbers (p < 0.005) compared with controls (acetic acid vehicle and 1mg/ml porcine serum albumin) and the positive control TGF-beta1 added at 10 ng/ml. Increased contraction with EMP and recombinant amelogenin was most pronounced after the first day of incubation and was associated with elevated (p < 0.005) TGF-beta1 levels in conditioned medium. In conclusion, the amelogenin component of EMP augmented fibroblast-driven collagen matrix remodelling, at least partially, by increasing the endogenous production of TGF-beta1. These effects of EMP/amelogenin may be beneficial for cutaneous wound healing.

Clinical Evaluation of an Enamel Matrix Protein Derivative Combined With Either a Natural Bone Mineral or β-Tricalcium Phosphate

BACKGROUND

The purpose of the present study was to compare the healing of deep intrabony defects following treatment with an enamel matrix protein derivative (EMD) combined with either a natural bone mineral (NBM) or beta-tricalcium phosphate (beta-TCP).

METHODS

Twenty-four patients with advanced periodontal disease, each of whom displayed one intrabony defect, were randomly treated with a combination of either EMD + NBM or EMD + beta-TCP. Clinical evaluation was performed at baseline and 1 year following therapy.

RESULTS

No differences in any of the investigated parameters were observed at baseline between the two groups. Healing was uneventful in all patients. At 1 year after therapy, the sites treated with EMD + NBM showed a reduction in mean probing depth (PD) from 7.9 +/- 1.0 mm to 3.2 +/- 0.6 mm and a change in mean clinical attachment level (CAL) from 8.8 +/- 1.1 mm to 4.5 +/- 0.6 mm (P < 0.001). In the group treated with EMD + beta-TCP, the mean PD was reduced from 7.8 +/- 1.2 mm to 3.2 +/- 0.9 mm, and the mean CAL changed from 8.8 +/- 1.2 mm to 4.7 +/- 1.2 mm (P < 0.001). In both groups, all sites gained at least 3 mm of CAL. CAL gains of 4 or 5 mm were measured in the majority of the cases (75%), irrespective of treatment modality. No statistically significant differences in terms of PD reductions and CAL gains were observed between the two groups.

CONCLUSION

Within the limits of the present study, both therapies resulted in significant PD reductions and CAL gains 1 year after surgery.

Enhanced proliferation, attachment and osteopontin expression by porcine periodontal cells exposed to Emdogain®

Emdogain (EMD) is an enamel matrix derivative extracted from developing porcine teeth with demonstrated periodontal regenerative potential. EMD has been shown to influence a number of properties of periodontal ligament cells including proliferation, cell attachment and matrix synthesis. To date, the effect of EMD on the epithelial cell rests of Malassez (ERM) is unknown. In this study, periodontal ligament fibroblasts, ERM, alveolar bone cells and gingival fibroblasts were obtained from porcine periodontal ligament, alveolar bone and gingiva. This study investigated, in vitro, the effect of EMD at three concentrations on proliferation, cell attachment and expression of mRNA for two mineralised tissue-related proteins (osteopontin and bone sialoprotein). As for other periodontal cells, the ERM proliferative response was enhanced by EMD. Attachment assays revealed a highly significant increase for ERM and gingival fibroblasts after EMD treatment at all concentrations. This study has also shown that EMD stimulated expression of osteopontin mRNA by ERM and alveolar bone cells. The results from this study provide evidence that EMD enhanced cellular events related with proliferation, attachment and osteopontin mRNA expression by porcine periodontal cells, in a manner consistent with its role in periodontal regenerative therapy.

Enamel matrix derivative promotes osteoclast cell formation by RANKL production in mouse marrow cultures

OBJECTIVES

Enamel matrix derivative (EMD) is used clinically to promote periodontal tissue regeneration, however, there are few reports regarding effects of EMD on bone metabolism. We evaluated the influence of EMD on osteoclast formation using in vitro bone marrow culture.

METHODS

Bioactive fractions were purified from EMD by reverse-phase HPLC on a C18 hydrophobic support, then mouse bone marrow cells were cultured with EMD or its purified fractions for 8 days. Following tartrate resistant acid phosphatase (TRAP) staining, TRAP-positive multinucleated cells were counted. The expression of receptor activator of NF-kappaB ligand (RANKL) in osteoblastic cells was detected using immunoblotting.

RESULTS

EMD was dissolved in 0.1% (vol/vol) trifluoroacetic acid and applied to a C18 column for HPLC. Two major peaks were obtained of which the second (fraction numbers 21-25) was found to induce the formation of osteoclasts in mouse marrow cultures. Further, osteoprotegerin completely inhibited osteoclast formation in mouse marrow cultures with or without osteoblastic stromal cells, when being cultured with EMD or its purified fractions. In addition, Western blot analysis revealed the presence of RANKL in mouse osteoblastic cells stimulated with EMD or its purified fractions.

CONCLUSION

Our results indicate that EMD induces the formation of osteoclasts through RANKL expressed by osteoblastic cells, and suggest that EMD may regulate both bone formation and bone resorption during periodontal tissue regeneration.

The use of enamel matrix derivative in the treatment of periodontal defects: a literature review and meta-analysis

BACKGROUND

Periodontal disease results in the loss of the attachment apparatus. In the last three decades, an increasing effort has been placed on seeking procedures and materials to promote the regeneration of this tissue. The aim of this paper is to evaluate the effect of enamel matrix derivative (EMD) during regenerative procedures. In addition, a meta-analysis is presented regarding the clinical results during regeneration with EMD, to gain evidence as to what can be accomplished following treatment of intrabony defects with EMD in terms of probing depth reduction, clinical attachment level gain, defect fill (using re-entry studies), and radiographic parameters.

METHODS

The review includes in vitro and in vivo studies as well as human case reports, clinical comparative trials, and histologic findings. In addition, a meta-analysis is presented regarding the regenerative clinical results. For this purpose, we used 28 studies-including 955 intrabony defects treated with EMD that presented baseline and final data on probing depth, clinical attachment level (CAL) gain, or bone gain-to calculate weighted mean changes in the different parameters. The selected studies were pooled from the MEDLINE database at the end of May, 2003.

RESULTS

The meta-analysis of intrabony defects treated with EMD resulted in a mean initial probing depth of 7.94 +/- 0.05 mm that was reduced to 3.63 +/- 0.04 mm (p = 0.000). The mean clinical attachment level changed from 9.4 +/- 0.06 mm to 5.82 +/- 0.07 mm (p = 0.000). These results were significantly better than the results obtained for either open-flap debridement (OFD) or guided tissue regeneration (GTR). In contrast, histologically, GTR is more predictable than EMD in terms of bone and cementum formation. No advantage was found for combining EMD and GTR. Xenograft, or EMD and xenograft, yielded inferior results compared with EMD alone, but a limited number of studies evaluated this issue. Promising results were noted for the combination of allograft materials and EMD.

CONCLUSIONS

EMD seems to be safe, was able to regenerate lost periodontal tissues in previously diseased sites based on clinical parameters, and was better than OFD or GTR. Its combination with allograft materials may be of additional benefit but still needs to be further investigated.

Effect of enamel matrix derivative on periodontal ligament cells in vitro is diminished by Porphyromonas gingivalis

BACKGROUND

Enamel matrix derivative (EMD) has been shown to possess a mitogenic effect to induce effective periodontal regeneration, however, it is unclear whether periodontal pathogens can modulate the effect of EMD. The present study examined the influence of Porphyromonas gingivalis on EMD-stimulated periodontal ligament (PDL) cells.

METHODS

P. gingivalis ATCC33277 and its mutants deficient in fimbriae (delta fimA) or gingipains (delta rgpA delta rgpB, delta kgp, and delta rgpA delta rgpB delta kgp) were employed. PDL cells were grown on EMD-coated dishes and infected with P. gingivalis wild strain or a mutant. Cell migration and proliferation were then evaluated with an in vitro wound healing assay. The expression of transforming growth factor-beta1 (TGF-beta1) and insulin-like growth factor I (IGF-I) mRNA by PDL cells was examined. Further, the degradation and phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) as well as paxillin in infected PDL cells were estimated using Western blot analysis.

RESULTS

P. gingivalis ATCC33277 inhibited the migration and proliferation of PDL cells on EMD-coated dishes, and the mutants delta fimA, delta rgpA delta rgpB, and delta kgp showed the same effects. Further, each of these organisms diminished the expression of TGF-beta1 and IGF-I mRNA, as well as the phosphorylation of ERK1/2 from EMD-stimulated PDL cells. In addition, total paxillin protein was markedly degraded by both the wild-type strain and each of the mutants except for delta rgpA delta rgpB delta kgp, which showed a negligible effect in all of the assays with EMD-stimulated PDL cells.

CONCLUSION

These results suggest that P. gingivalis diminishes the effect of EMD on PDL cells in vitro through a cooperative action of gingipains.

In vitro effects of enamel matrix proteins on rat bone marrow cells and gingival fibroblasts

Emdogain (EMD), a formulation of Enamel Matrix Proteins (EMP), is used clinically for periodontal regeneration, where it stimulates cementum formation and promotes gingival healing. In this study, we investigated the in vitro effects of EMD on rat bone marrow stromal cells (BMSC) and gingival fibroblasts (GF). EMD (at 25 micro g/mL) increased the osteogenic capacity of bone marrow, as evidenced by approximately three-fold increase in BMSC cell number and approximately two-fold increase in alkaline phosphatase (ALP) activity and mineralized nodule formation. The presence of EMD in the initial stages (first 48 hrs) of the culture was crucial for this effect. In contrast, EMD did not induce osteoblastic differentiation of GF (evidenced by lack of mineralization or ALP activity) but increased up to two-fold both their number and the amount of matrix produced. These in vitro data on BMSC and GF could explain the promotive effect of EMD on bone formation and connective tissue regeneration, respectively.

Emdogain promotes osteoblast proliferation and differentiation and stimulates osteoprotegerin expression

PURPOSE

The purpose of this study was to investigate the effects of EMD on the growth and differentiation of osteoblastic cells (MC3T3-E1) and on the expression of osteoprotegerin (OPG), a key cytokine that inhibits osteoclastogenesis and osteoclast function.

STUDY DESIGN

MC3T3-E1 cells were treated with 100 microg/mL EMD in serum-free medium for 1, 2, 3, 5, and 7 days, or in 2% fetal bovine serum (FBS) for 3 weeks. Cells incubated without EMD served as negative control. At the end of each incubation period, cell numbers were counted and total cellular mRNA was extracted. Northern blot analysis and RT-PCR were performed to determine the mRNA levels of core binding factor alpha (Cbfa1), collagen alpha1 (I), bone sialoprotein (BSP), osteocalcin (OC), insulin-like growth factor I (IGF-I), and OPG. Alkaline phosphatase (ALP) activity was also determined and compared between treatment and control groups.

RESULTS

A marked increase in cell numbers was observed in EMD-treated groups from day 2 to day 7 (P < .01). mRNA expression of collagen alpha1 (I), BSP, OC, OPG, and IGF-I were up-regulated in cells treated with EMD. ALP activity was significantly increased by EMD treatment after 3-week culture under differentiating conditions (P < .05). The expression of Cbfa1 was not affected by EMD treatment from day 1 to day 5; the levels were elevated after culturing for 3 weeks in EMD-treated cells.

CONCLUSIONS

EMD promotes both proliferation and differentiation of MC3T3-E1 cells and indirectly inhibits osteoclastogenesis and osteoclast function by stimulating the expression of OPG.

Effect of enamel matrix proteins on the periodontal connective tissue-material interface after wound healing

The periodontal ligament has the potential to regenerate a complete periodontal connective tissue attachment, starting with the deposition of cementum, on pathologically exposed root surfaces as well as several materials including titanium oxide. However, most commonly used dental materials result in a fibrous encapsulation or a chronic inflammatory response after periodontal wound healing rather than the formation of a periodontal connective tissue attachment. Recently, an extract of porcine enamel matrix (Emdogain(R), EMD) has been reported inductive of cementum formation in both in vivo and in vitro studies. The aim of this study was to determine the effect of EMD, when applied to materials previously reported not supportive of periodontal connective tissue formation, on the periodontal connective tissue-material interface obtained with these materials in vivo. Bilateral osteotomies were performed on the mandible of a Yucatan minipig exposing the buccal root surface of four premolars. A series of four preparations were placed in each root surface that were subsequently filled with calcium hydroxide, gutta percha, mineral trioxide aggregate (MTA), or left unfilled. One side, in addition, received an application of EMD prior to surgical closure. A bioabsorbable surgical barrier membrane was placed over the osteotomy sites to exclude gingival connective tissue from the wound-healing environment. The mucoperiosteal flaps were then readapted and sutured in position. The animal was euthanized 10 weeks after the procedure, block sections obtained and prepared for light microscopy. Results demonstrated complete regeneration of alveolar bone and periodontal ligament in all four teeth from the EMD-treated side. Fibers from the periodontal ligament were observed to insert into a mineralized matrix consistent with cementum on all four root preparations. In contrast, massive root resorption without regeneration of alveolar bone was found on all teeth from the side not treated with EMD. The results of this pilot study suggest that the application of EMD to material surfaces that normally do not support periodontal connective tissue attachment formation can alter the type of periodontal connective tissue interface obtained with these materials.

Effect of enamel matrix proteins on the phenotype expression of periodontal ligament cells cultured on dental materials

Cells within the periodontal ligament have the potential to regenerate a periodontal connective tissue attachment on pathologically exposed root surfaces as well as on several material surfaces including titanium. However, rather than a periodontal connective tissue attachment, a fibrous encapsulation or chronic inflammatory response has been reported at the material connective tissue interface for most dental materials. Cementum is the first tissue of the periodontal connective tissue attachment to develop and the secretion of enamel matrix related proteins on the newly mineralized dentin surface precedes and is thought to induce cementum formation. Enamel matrix-related proteins may also function in the adult because the application of an acid extract of porcine enamel protein matrix (Emdogain(R), EMD) on pathologically exposed root surfaces has been shown to result in cementum regeneration. Therefore, the objective of the present study was to determine whether the application of EMD to materials that do not normally support cementogenesis in vivo would alter the in vitro phenotype of periodontal ligament (PDL) cells including the synthesis of cementum-associated extracellular matrix proteins. Primary PDL cells were established from 21-day-old Sprague-Dawley rats, and were cultured on four materials commonly encountered in dental practice (gutta percha, calcium hydroxide, amalgam, and super EBA cement) with and without the application of EMD. After 7 or 14 days of culture, total-DNA content, collagen synthesis, alkaline phosphatase activity, and the synthesis of a 42-kDa cementum-associated extracellular matrix protein were determined. PDL cells cultured on all materials had decreased total DNA content. The application of EMD further decreased total DNA content. PDL cells cultured on gutta percha and calcium hydroxide with the application of EMD had similar levels of collagen synthesis and alkaline phosphatase activity but also expressed a 42-kDa cementum extracellular matrix-associated protein when compared to the other groups. These results suggest that EMD can alter the phenotype of PDL cells when cultured on these dental materials.

Effect of Emdogain on human periodontal fibroblasts in an in vitro wound-healing model

OBJECTIVE

The aim of this study was to evaluate the influence of Emdogain (EMD) on cultured gingival fibroblasts, periodontal ligament fibroblasts and dermal fibroblasts, using an in vitro model of wound healing.

BACKGROUND

Enamel matrix derivative has been demonstrated to promote periodontal regeneration. However, the precise mechanisms by which this agent acts are still unclear.

METHODS

The effect of EMD on proliferation of the cells was studied using subconfluent cultures of gingival fibroblasts and periodontal ligament fibroblasts. The cells were made quiescent overnight and then stimulated with various concentrations of EMD (10, 50, 100 and 150 microg/ml) for 24 h. Negative and positive controls were cells cultured in media containing 0.2% and 10% fetal calf serum (FCS). The DNA synthesis was measured by the cellular uptake of [3H]thymidine. For in vitro wounding the cells were cultured, wounded and stimulated with 0.2% FCS, 10% FCS and EMD at a concentration of 20 microg/ml. The percentage of wound fill after treatment was measured after d 1, 4, 6, 12 and 16. The proliferation of cells was also calculated by the extent of incorporation of crystal violet.

RESULTS

The results demonstrated that cells in vitro fill an empty space by a combination of proliferation and cell migration. The most rapid closure of a wound area occurred where both proliferation and migration can occur as was seen when wounded cultures were maintained in 10% FCS or at a concentration of 20 microg/ml EMD which promoted proliferation.

CONCLUSIONS

Therefore, EMD appears to exert an influence on cells that is compatible with improved wound healing.

Regulatory mechanisms of periodontal regeneration

The periodontal ligament, located between the cementum and the alveolar bone, has a width ranging from 0.15 to 0.38 mm. Regeneration and homeostasis of the periodontal ligament are highly significant functions in relation to periodontal therapy, tooth transplantation or replantation, and orthodontic tooth movement. The purpose of this review is to discuss the regulatory mechanisms of regenerative and homeostatic functions in the periodontal ligament based on currently published studies and also on our own experimental data. We consider the capability of the ligament tissue to promote or to suppress calcification in connection with bone and cementum formation and the maintenance of the periodontal ligament space. Also discussed are the involvement of the periodontal ligament tissue in the regenerative ability, cell proliferation, growth and differentiation factors, extracellular matrix proteins, homeostatic phenomena, function of Malassez epithelial rests, tooth movement, or occlusal loading. Regulatory mechanisms for regeneration and homeostasis of the periodontal ligament are hypothetically proposed.

Effects of enamel matrix protein application on the viability, proliferation, and attachment of human periodontal ligament fibroblasts to diseased root surfaces in vitro

OBJECTIVES

The purpose of this research was to examine the influence of enamel matrix proteins (EMP) on the viability, proliferation, and attachment of periodontal ligament fibroblasts (PDLF) to diseased root surfaces.

MATERIALS AND METHODS

Primary cell cultures of PDFL were obtained from clinically healthy third molars or premolar teeth. Viability and proliferation rates were carried out over a 10-day period. A total of 80,000 cells were plated in 24-well plates followed by EMEM with 10% FBS (positive control) and EMEM plus EMP at 25, 50, 75, and 100 micro g/ml. Cells were harvested on days 1, 3, 5, 7, and 10 and viability was performed utilizing an MTS assay. PDLF proliferation rates were assessed by a CyQUANT GR dye assay. SEM analysis was used to examine the qualitative effects of cellular attachment to diseased root surfaces following EMP compared to nontreated controls.

RESULTS

The results indicated that viability was negatively affected for higher doses over time while lower doses displayed viability effects similar to control. Proliferation, however, appeared to be ameliorated following exposure to EMP. The SEM analysis suggests that cellular attachment to diseased dentin was enhanced following EMP application.

CONCLUSION

These in vitro studies support the concept that EMP may act as a suitable matrix for PDLF.

Treatment of intrabony periodontal defects with enamel matrix derivative: a literature review

The enamel matrix derivative (EMD) has been recently introduced in the periodontal field to overcome short-comings associated with currently available regenerative techniques. Information accumulated over the past years with application of EMD guided regeneration (EGR) in intrabony periodontal defects allowed a thorough evidence-based retrospective analysis. Clinical data from EMD controlled studies were pooled for meta-analysis and weighted according to the number of treated defects. Clinical attachment gain amounted to 3.2 +/- 0.9 mm (33% of the original attachment level) and probing reduction averaged 4.0 +/- 0.9 mm (50% of the baseline probing depth) for a total of 317 lesions with a mean baseline depth of 5.4 +/- 0.8 mm. Improvements in clinical parameters achieved with EMD were statistically significant in reference to preoperative measurements. However, despite the overall efficacy of EGR therapy, a significant variation in clinical outcomes was observed. Similar therapeutic results were reported in studies where EGR was compared directly to guided tissue regeneration. However, the controlled clinical trials did not have adequate statistical power to firmly support superiority or equivalency between the 2 regenerative therapies. The statistical superiority of EGR over treatment with open flap debridement has been established. Preliminary histologic investigations with surgically created defects and experimental periodontal lesions demonstrated the ability of EGR to induce formation of acellular cementum and promote significant anaplasis of the supporting periodontal tissues. The potential of EMD to encourage periodontal regeneration was also confirmed in human intrabony defects. However, recent human histologic studies have questioned both the consistency of the histologic outcomes and the ability of EGR to predictably stimulate formation of acellular cementum. Identifying clinical modifying parameters and understanding cellular interactions are apparently essential for the development of methodologies to enhance predictability and extent of EGR clinical and histologic results.

Expression profiling of periodontal ligament cells stimulated with enamel matrix proteins in vitro: a model for tissue regeneration

Several studies have examined the role of enamel matrix proteins in root formation and periodontal regeneration, although most of these have focused on a few specific genes which had previously been implicated. However, recent advances in expressional profiling have made it possible to examine the range of genetic responses involved in these processes. In the present experiments, we have therefore utilized this technique to determine the effects of enamel matrix proteins on the gene activities of periodontal ligament cells in vitro. Such cells were found to have an elevated level of RNA synthesis compared with control cells. Moreover, hybridization of the cDNA prepared from this RNA to gene array filters showed that there was differential expression of 121 genes, most of which had not previously been associated with periodontal regeneration. Some of these selective changes in gene activity might thus reflect the fundamental events that underlie periodontal development.

A clinical comparison of a bovine-derived xenograft used alone and in combination with enamel matrix derivative for the treatment of periodontal osseous defects in humans

BACKGROUND

Enamel matrix protein derivative (EMD) and particulate anorganic cancellous bovine-derived bone xenograft (BDX) have both shown favorable clinical results in reducing intrabony periodontal defects as compared to open flap debridement alone. These materials have shown results comparable to those obtained with guided tissue regeneration. The primary aim of the present study was to evaluate the effectiveness of EMD combined with BDX as compared to BDX alone, with a secondary aim to compare the treatment outcomes of the 2 modalities.

METHODS

Seventeen patients with paired intrabony defects and probing depths measuring > or = 5 mm who were being treated for chronic periodontitis were selected for this controlled, blinded, split-mouth study. Following non-surgical periodontal therapy, sites were randomly selected to receive either a combination of EMD and BDX (test group) or BDX alone (positive control group). Baseline and 6-month surgical reentry measurements were taken by a calibrated examiner blinded to the treatment. A paired Student t test was utilized to evaluate differences between baseline and post-treatment and between the treatment groups.

RESULTS

Favorable clinical outcomes for both hard and soft tissue measurements were achieved for both treatment groups when compared to baseline (P < 0.001). There was no statistically significant difference for any of the measured clinical parameters. Probing depth reduction for the test group and control group was 4.2 +/- 1.1 mm and 3.9 +/- 1.3 mm, respectively (P > 0.8). Mean gain in clinical attachment levels for the test and control groups was 3.8 +/- 0.9 mm and 3.7 +/- 1.5 mm, respectively (P > 0.6). Hard tissue measurements obtained at surgical reentry were used to calculate the bone fill (BF) and percent bone fill (%BF). The BF was 3.2 +/- 1.4 mm and 3.0 +/- 1.2 mm (P > 0.6), and the %BF was 63.3 +/- 16.3% and 67.0 +/- 19.0% (P > 0.4) for the EMD + BDX and BDX groups, respectively.

CONCLUSIONS

In summary, both the particulate anorganic cancellous bovine-derived bone xenograft used alone and in combination with enamel matrix derivative are effective for the treatment of human intrabony periodontal lesions.

Clinical comparison of an enamel matrix derivative used alone or in combination with a bovine-derived xenograft for the treatment of periodontal osseous defects in humans

BACKGROUND

The combination of bone replacement graft materials has been suggested for the treatment of periodontal osseous defects. The purpose of this study was to evaluate the effectiveness of enamel matrix derivative (EMD) combined with a bovine-derived xenograft (BDX) as compared to EMD alone in the treatment of intraosseous defects in patients with moderate to advanced periodontitis.

METHODS

Sixteen adult patients with at least 2 intrabony defects were entered in this split-mouth design study. Defects were treated with EMD alone or EMD + BDX. Reentries were performed 6 to 8 months after initial surgery. The following soft and hard tissue measurements were recorded prior to initial surgery and at reentry: probing depth (PD), gingival margin location, clinical attachment level (CAL), depth of defect, and crestal bone level. Statistical analyses were performed to determine changes in PD, CAL, fill of osseous defect, and crestal resorption. Percentages of bone fill (%BF) and defect resolution (%DR) were also calculated.

RESULTS

The most significant results were that gingival recession was greater for the group treated with EMD alone (0.8 +/- 0.8 mm) compared to EMD + BDX (0.3 +/- 0.6 mm) (P = 0.04) and bone fill was greater for EMD + BDX (4.0 +/- 0.8 mm) compared to EMD alone (3.1 +/- 1.0 mm) (P = 0.02). The measures for PD reduction, attachment level gain, crestal resorption, %BF, and %DR did not present a statistically significant difference (P > 0.10).

CONCLUSIONS

This study evaluated the performance of EMD + BDX and EMD alone. The results demonstrated that a significant improvement in clinical parameters was observed. When comparing both modalities, a statistically significant difference was only found for gingival recession and bone fill, yielding a more favorable outcome towards the combined approach.

Application of enamel matrix derivative in autotransplantation of an impacted maxillary premolar: a case report

BACKGROUND

The success of tooth transplantation or replantation depends on the viability of periodontal ligament in the planted tooth. Mechanical injury to periodontal tissues frequently results in dental root resorption and dental ankylosis, which leads to the failure of transplantation or replantation. Enamel matrix derivative (EMD) has been recently used to induce periodontal regeneration. In this report, we show a clinical case of EMD application in the transplantation of an inversely impacted and immature tooth.

METHODS

An impacted second premolar was found in the right maxilla of a 16 year-old girl. The tooth was inversely impacted and the dental root was incomplete. When transplantation was carried out, EMD was applied to the periodontal tissues of the extracted premolar. The tooth was fixed at the correct position and the clinical condition was followed for evaluation for 6 months.

RESULTS

Radiographs after 3 months exhibited new bone formation surrounding the transplanted tooth. After 6 months, considerable growth of dental root was evident, periodontal ligament-like radiolucency appeared, the vital reaction of the planted tooth was detected, and there were no signs of root resorption or ankylosis.

CONCLUSION

Short-term results from this case indicate that EMD application was effective in the transplantation of an inversely impacted and immature tooth and that EMD might contribute to the growth of dental root and to the prevention of ankylosis.