Comparison of infrabony defects treated with enamel matrix derivative versus guided tissue regeneration with a nonresorbable membrane

AIM: The purpose of the present multicenter clinical trial was to compare the efficacy of two different procedures in the treatment of infrabony defects: guided tissue regeneration (GTR) with nonresorbable membranes and enamel matrix derivative (EMD). MATERIAL AND METHODS: Six centers participated in this study. Ninety-eight patients with an interproximal infrabony defect were selected. All patients were treated with an initial phase of scaling and root planing, and at the study's baseline the selected defects presented a value of probing depth (PD) > or =6 mm with an infrabony component > or =4 mm. Forty-nine patients were treated with GTR procedures (using ePTFE membranes (Gore-Tex W.L. Gore and Associates, Flagstaff, AZ, USA)) and forty-nine with EMDs (Emdogain (U Biora AB Malm, Sweden)). The efficacy of each treatment modality was investigated through covariance analysis. RESULTS: The patients were reevaluated at one year postop. Probing attachment level (PAL) gain and PD reduction were analyzed. In the Emdogain group the PAL before surgery (PAL 0) and the PD before surgery (PD 0) were respectively 9.9+/-1.4 and 8.5+/-1.6 mm. The PAL gain and the PD reduction at 1 year postsurgery were respectively 4.1+/-1.8 and 5.3+/-1.9 mm. The group of patients treated with membranes showed that PAL 0 and PD 0 were respectively 8.9+/-1.9 and 8.1+/-1.9. The PAL gain was 4.3+/-1.9 mm and the PD reduction was 5.6+/-1.5 mm. The mean PAL gain expressed by percentage (PAL gain/PAL 0) for the group treated with EMD was 41%, while it was 48% for the group treated with GTR. Results from our analysis suggest that there is no statistically significant difference between GTR and EMD treatments in terms of PAL gain, PD reduction and recession variation. Applying the regression model to a group of patients with a PAL 0 > or =8 mm, we observed a better clinical outcome in terms of PAL gain (difference of 0.3 mm) in patients treated with the GTR procedure compared to those treated with EMD. Covariance analysis showed a strong correlation in both groups of patients between PAL gain and full mouth bleeding score, and between PAL gain and defect morphology and depth.     

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.

     

Long-term stability of the mucogingival complex following guided tissue regeneration in gingival recession defects

Abstract. The purpose of the present study was to evaluate the stability of soft tissue conditions in gingival recession defects treated with guided tissue regeneration (GTR). The study population was selected among those patients who had been treated with GTR procedures for Miller's class I or II, deep (≥3 mm), buccal gingival recession defects. Defects were included only when they had revealed recession depth reduction ≥2 mm and root coverage ≥60% at 6 months following GTR treatment. These defects were regarded as successfully treated and scheduled for further monitoring. 20 patients, 11 male and 9 female, aged 23 to 57 years (mean age: 33.2 years), each contributing 1 defect, were selected. 9 patients were smokers (≥10 cigarette per day). Recession depth (RD), probing depth (PD), clinical attachment level (CAL), and width of keratinized gingiva (KG) were assessed immediately before surgery at 6 months post-surgery (baseline examination), and at 4 years post-surgery (4-year examination). At baseline examination. RD reduction was 3.6±0.9 mm (mean root coverage: 80%). CAL gain amounted to 4.2± 1.3 mm. 60% of the defects showing CAL gain ≥4 mm. KG increased from 1.9±1.2 mm at presurgery examination to 3.1±0.9 mm at baseline examination. At 4-year examination, no significant changes from baseline RD, CAL and KG recordings were observed. Differences in baseline-4 year changes between smokers and non-smokers were not statistically significant. The results of the present study demonstrate that clinical outcome achieved following GTR procedure in gingival recession defects can be maintained over periods up to 4 years.     

Healing response of gingival recession defects following guided tissue regeneration procedures in smokers and non-smokers

Abstract This retrospective study evaluated healing response in gingival recession defects following guided tissue regeneration (GTR) in smokers. 22 systemically healthy patients who had been treated for deep (4 mm), buccal. Miller's class I or II gingival recession defects with ePTFE membranes were included. Patients were regarded as smokers if they smoked more than 10 cigarettes/day at the time of surgical procedure. Occasional and former smokers were excluded. 9 patients (6 male, mean age 29 years) were smokers, while 13 patients (4 male, mean age 35 years) were non smokers. Clinical parameters, recorded pre surgery and at 6 months post surgery. included defect-specific plaque (DPI) and bleeding on probing (BoP) scores, recession depth (RD). probing depth (PD). clinical attachment level (CAL). and keratinized tissue width (KG). Extent of membrane exposure (ME) and newly formed tissue (NFT) gain were assessed at membrane removal. Statistical analysis revealed no significant differences between smokers and non-smokers in demographic and pre surgery defect characteristics. DPI and BoP scores were similar pre surgery and remained almost unchanged thorough out the observation interval in both groups. ME was significantly greater in smokers (2.6±1.4 mm) than in non smokers (1.3±0.6 mm). NFT gain was 2.8±1.0 mm in smokers and 3.6±1.4 mm in non-smokers, the difference being not statistically significant. Smokers showed significantly less RD reduction and root coverage (2.5±1.2 mm and 57%, respectively) compared to non-smokers (3.6±1.1 mm and 78%, respectively). In conclusion, the results indicate that treatment outcome following GTR in gingival recession defects is impaired in cigarette smokers.     

Gingival recession defects and guided tissue regeneration: a review

The last decade has seen an increasing number of clinical reports on guided tissue regeneration (GTR) for reconstruction of gingival recession defects. This article reviews the value of GTR in the management of gingival recession defects based on records from such reports. Studies and case-series using nonresorbable and bioresorbable membranes, studies comparing GTR to the subepithelial connective tissue graft (CTG) procedure, and histologic reports of healing following GTR, published in the English language from 1985 to 2000, were identified using a Medline search and were included in the data-base for this review. The Following pre- and post-treatment data were collated and evaluated for each of the reports: gingival recession depth, probing depth, clinical attachment level, and width of the keratinized gingiva. In perspective of the limitations of the studies reviewed, it has been shown that GTR may be used for reconstruction of gingival recession detects. Importantly it has not been shown that GTR provides an added clinical benefit for the patient treatment planned for reconstruction of gingival recession defects. i.e. GTR does not appear to offer a significant advantage over mucogingival procedures such as the connective tissue graft or the advanced flap procedure. It is imperative to recognize inherent technical difficulties associated with GTR including primary would closure and secondary membrane exposure: membrane exposures being negatively correlated to desired clinical outcomes. Also, membrane exposures appear consistently more common in smokers than in non-smokers. It is also imperative to recognize shortcomings and adverse effects including space maintenance and unacceptable foreign body reactions associated with some bioresorbable GTR technologies.     

Healing of fenestration-type defects following treatment with guided tissue regeneration or enamel matrix proteins

The aim of the present study was to evaluate histologically in monkeys the healing in acute fenestration-type defects following treatment with guided tissue regeneration (GTR) or enamel matrix proteins (EMD). Standardized ”critical size” fenestration-type defects were produced surgically at the vestibular aspect of teeth 13, 23, 33, 43 in three monkeys (Macaca fascicularis). The vestibular bone plates were removed and the root surfaces were debrided by means of hand instruments in order to completely remove the root cementum. Following root conditioning with ethylenediaminetetraacetate (EDTA), the defects were treated using one of the following therapies: (1) GTR, (2) EMD, or (3) control (coronally repositioned flaps). After 5 months the animals were killed and perfused with 10% buffered formalin for fixation. Specimens containing the defects and surrounding tissues were dissected free, decalcified in EDTA, and embedded in paraffin. Eight-micrometer-thick step serial histological sections were cut in a vestibulo-oral direction, stained with hematoxylin and eosin or oxone-aldehyde-fuchsin-Halmi, and subsequently examined under the light microscope. The results showed that, in the defects treated with GTR, a new connective tissue attachment (i.e., new cementum with inserting collagen fibers) and new bone formation had consistently occurred, whereas, in the defects treated with EMD or with coronally repositioned flaps, new attachment and new bone reformed to a varying extent. The quality of the cementum did not differ after EMD, GTR, or flap surgery. It was concluded that GTR treatment with bioresorbable membranes seems to predictably promote new attachment and new bone formation, whereas the application of EDTA or EMD may also enhance periodontal healing to a certain extent. Further studies with higher numbers of animals and defects are needed in order to definitely clarify the effect of root surface conditioning with EDTA and EMD on periodontal healing. Received: 14 October 1999 / Accepted: 29 November 1999     

Five-year results following treatment of intrabony defects with enamel matrix proteins and guided tissue regeneration

BACKGROUND: Treatment with enamel matrix proteins (EMD) or guided tissue regeneration (GTR) has been shown to enhance periodontal regeneration. However, until now there are limited data on the long-term results following these treatment modalities. Aim: The aim of the present clinical study was to present the 5-year results following treatment of intrabony defects with EMD, GTR, combination of EMD and GTR, and open flap debridement (OFD). MATERIAL AND METHODS: Forty-two patients, each of whom displayed one intrabony defect of a probing depth of at least 6 mm, were randomly treated with one of the four treatment modalities. The following parameters were evaluated prior to surgery, at 1 year and at 5 years after: plaque index, gingival index, bleeding on probing, probing pocket depth (PPD), gingival recession, and clinical attachment level (CAL). No statistically significant differences in any of the parameters were observed at baseline between the four groups. RESULTS: The sites treated with EMD demonstrated a mean CAL gain of 3.4+/-1.1 mm (p<0.001) and of 2.9+/-1.6 mm (p<0.001) at 1 and 5 years, respectively. The sites treated with GTR showed a mean CAL gain of 3.2+/-0.8 (p<0.001) at 1 year and of 2.7+/-0.9 mm (p<0.001) at 5 years. The mean CAL gain at sites treated with EMD+GTR was 3.0+/-1.0 mm (p<0.001) and 2.6+/-0.7 mm (p<0.001) at 1 and 5 years, respectively. The sites treated with OFD demonstrated a mean CAL gain of 1.6+/-1.0 mm (p<0.001) at 1 year and 1.3+/-1.2 mm (p<0.001) at 5 years. At 1 year, the only statistically significant difference between the four different treatments was found in terms of PPD reduction and CAL gain between EMD and OFD (p<0.05). However, at 5 years there were no statistically significant differences in any of the investigated parameters between the four different treatments. CONCLUSION: Within the limits of the present study, it may be concluded that the short-term clinical results following treatment with EMD, GTR, EMD+GTR, and OFD can be maintained over a period of 5 years.     

Ten-year results following treatment of intra-bony defects with enamel matrix proteins and guided tissue regeneration

Background: Surgery utilizing an enamel matrix protein derivative (EMD) or guided tissue regeneration (GTR) has been shown to promote periodontal regeneration.
Aim: To evaluate the 10-year results following treatment with EMD, GTR, EMD+GTR, and open flap debridement (OFD).
Material and Methods: Thirty-eight patients out of an initial group of 56 participants were treated with one of the four modalities. Results were evaluated before surgery, at 1 year, and at 10 years. Primary outcome variable was CAL change.
Results: Treatment with EMD yielded a mean CAL gain of 3.4±1.0 mm ( p <0.001) and 2.9±1.4 mm ( p <0.001) at 1 and 10 years, respectively. GTR resulted in a mean CAL gain of 3.2±1.4 ( p <0.001) at 1 year and 2.8±1.2 mm ( p <0.001) at 10 years. Mean CAL gain in the EMD+GTR group was of 3.3±1.1 mm ( p <0.001) and 2.9±1.2 mm ( p <0.001) at 1 and 10 years, respectively. Treatment with OFD demonstrated a mean CAL gain of 2.0±1.2 mm ( p <0.01) at 1 year and 1.8±1.1 mm ( p <0.01) at 10 years. Compared with OFD, the three regenerative treatments resulted in statistically significant ( p <0.05) higher CAL gain, at both 1 and 10 years. The CAL change between 1 and 10 years did not present statistically significant differences in any of the four groups.
Conclusion: The present results indicate that the clinical outcomes obtained with all four approaches can be maintained over a period of 10 years.     

Healing of human intrabony defects following treatment with enamel matrix proteins or guided tissue regeneration

The aim of the present study was to evaluate histologically in humans the healing of advanced intrabony defects following treatment with enamel matrix proteins (EMD) or guided tissue regeneration (GTR). Fourteen patients, each of them displaying 1 advanced intrabony defect around teeth scheduled for extraction were included in the study. The defects were treated randomly either with an enamel matrix protein derivative (Emdogain ®, BIORA AB, Malmö, Sweden) or with a bioabsorbable membrane (Resolut®, Regenerative Material. W.L. Gore & Assoc, Flagstaff, Arizona, USA). At baseline the mean probing pocket depth (PPD) in the EMD group was 11.3 ± 1.8 mm and the mean clinical attachment level (CAL) 12.1 ± 2.0 mm. whereas in the GTR group the mean PPD was 11.4 ± 2.2 mm and the mean CAL 13.3 ± 2.3 mm. Healing was uneventful in all cases. Neither allergic reactions against EMD or the bioabsorbable membrane. nor suppuration or abscesses were observed. The clinical results revealed at 6 months in the EMD group a mean PPD of 5.6 ± 1.3 mm and a mean CAL of 9.1 ± 1.5 mm. In the GTR group the mean PPD was 5.6 ± 1.3 mm and the mean CAL 10.1 ± 1.5 mm. The histological analysis showed in the EMD group a mean 2.6 ± 1.0 mm of new attachment (i.e. new cementum with inserting collagen fibers) and a mean 0.9 ± 1.0 mm of new bone. In this group, the formation of new attachment was not always followed by bone regeneration. In the GTR group, the mean new attachment was 2.4 ± 1.0 mm and the mean new bone 2.1 ± 1.0 mm. In every case treated with GTR, the formation of new attachment was followed by a varying amount of new bone. After both types of regenerative treatment the newly formed cementum displayed a predominantly cellular character. The findings of the present study indicate that the treatment of intrabony defects with enamel matrix proteins or with bioabsorbable membranes enhances the formation of a new connective tissue attachment in humans.     

Split-mouth comparison of a coronally advanced flap with or without enamel matrix derivative for coverage of multiple gingival recession defects: 6- and 24-month follow-up

The aim of this study was to evaluate whether the use of enamel matrix derivative (EMD) improves clinical results of the coronally advanced flap (CAF) procedure in the treatment of multiple gingival recession defects. Ten patients presenting at least two adjacent buccal gingival recession defects affecting symmetric teeth on both sides of the maxilla were included in this study. Each set of multiple recession defects was assigned randomly to the test or control group. A bilateral simultaneous CAF procedure with vertical releasing incisions, with the adjunct of EMD for test sites, was performed. Clinical measurements (recession length, keratinized tissue, probing depth, and clinical attachment level) were assessed at baseline and 6 and 24 months after surgery by a blinded examiner. At the 6-month evaluation, both treatment procedures displayed good results with significant root coverage gain (CAF, 80.7% ± 20%; CAF + EMD, 82.8% ± 14%). A similar amount of relapse was noted at the 24-month evaluation when compared with the 6-month results (CAF, 71.0% ± 22%; CAF + EMD, 74.8% ± 16%). The use of EMD does not seem to significantly improve the results of the CAF procedure for root coverage in treatment of multiple recessions.     

Clinical evaluation of a combined regenerative technique with enamel matrix derivative, bone grafts, and guided tissue regeneration

The goal of this study was to evaluate the clinical changes obtained when intra-bony defects were treated with an enamel matrix derivative (EMD), a bone graft, and guided tissue regeneration. Fifty patients with a periodontal defect not associated with a furcation and with an attachment loss of at least 7.0 mm were included in this study. Full-thickness flaps were reflected, the roots were planed, EMD was applied, a demineralized freeze-dried bone allograft combined with EMD was placed, a bioabsorbable membrane was placed, and more EMD was applied. The defect areas were then sutured. At a mean of 5.3 months after treatment, there was a mean increase in recession of 0.7 mm, a mean reduction in probing depth of 5.7 mm, and a mean gain in attachment level of 5.0 mm. In this study there was more recession in smokers than in nonsmokers and in defects associated with anterior teeth. Additionally, the deeper defects (those with greater probing depths and attachment level loss) had the greatest reductions in probing depth and gains in attachment level. Based on this study, this technique proved itself to be an effective method to improve the clinical situation when treating periodontal defects not involving furcations.     

Connective tissue-bone onlay graft with enamel matrix derivative for treatment of gingival recession: a case report

We describe a case of gingival recession in which root coverage and coronal bone regrowth were achieved after treatment with a connective tissue-bone graft and enamel matrix derivative. The connective tissue-bone graft was harvested from a maxillary edentulous area and then curved to fit the root surfaces of the maxillary left central and lateral incisors. Enamel matrix derivative was applied to the root surfaces, and the connective tissue-bone graft was fixed to the interdental bone by a titanium screw. Six months later, the exposed roots were covered with thick gingiva, and coronal regrowth of thick bone was evident at reentry surgery. This technique is useful for esthetic restoration placement with an intracrevicular margin on teeth with a thin, receding gingiva.     

Comparison of treatments of infrabony defects with enamel matrix derivative, guided tissue regeneration with a nonresorbable membrane and Widman modified flap. A pilot study

BACKGROUND, AIMS: The purpose of the present study was to compare the efficacy of 3 different surgical procedures in the treatment of infrabony defects: guided tissue regeneration (GTR) with non-resorbable membranes, Widman modified flap (WMF) and enamel matrix derivative (EMD). METHOD: 30 patients with an infrabony component > or = 4 mm were selected. 10 were treated with expanded polytetrafluorethylene (ePTFE (Gore - Tex W. L. Gore and Associates, Flagstaff, AZ, USA)) membranes, 10 with WMF and 10 with enamel matrix derivatives (Emdogain (U Biora AB Malm, Sweden)). The efficacy of each treatment modality was investigated through regression analysis. Probing attachment level (PAL) gain, probing depth (PD) reduction and gingival recession (REC) variation were analyzed. RESULTS: Both Emdogain (enamel matrix derivative) and ePTFE treatment show significant better results as compared to the WMF procedure in which there were no significant changes in PAL gain and PD reduction at baseline and 1 year after surgery. CONCLUSIONS: Results from our analysis suggest that there is no statistically significant difference in PAL gain between GTR and EMD. The clinical outcomes of this pilot study may be of little significance, considering the small number of patients, but it has provided an important base for a controlled clinical trial (with a larger number of patients) which is currently in progress.     

Using absorbable collagen membranes for guided tissue regeneration, guided bone regeneration, and to treat gingival recession

This article reviews the role of barrier membranes in guided tissue regeneration (GTR) and guided bone regeneration (GBR), including the advantages of using absorbable barrier membranes in GTR and GBR and the unique properties of collagen membranes. The indications and contraindications for using collagen membranes for these procedures are examined, and successful cases are presented. Finally, the role of collagen membranes in the future of regenerative therapy is considered.     

Treatment of intrabony defects with enamel matrix proteins and guided tissue regeneration. A prospective controlled clinical study

BACKGROUND: Utilisation of enamel matrix proteins (EMD) and application of the guided tissue regeneration principle (GTR) are treatment modalities which both have been shown to result in periodontal regeneration. However, it is yet unknown whether the combination of EMD and GTR may additionally favor the regeneration process. AIM: The aim of the present controlled study was to evaluate clinically the treatment effect of EMD, GTR, combination of EMD and GTR, and flap surgery (control) on intrabony defects. MATERIAL AND METHODS: 56 patients each of whom displaying one intrabony defect of a depth of at least 6 mm were randomly treated with one of the treatment modalities. Prior to surgery and at one year after, the following parameters were evaluated by a blinded examiner: Plaque index (PlI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), gingival recession (GR) and clinical attachment level (CAL). No statistical significant differences between the four groups were observed at baseline for any of the investigated parameters. RESULTS: At 1 year after therapy, the sites treated with EMD demonstrated a mean PPD reduction of 4.1 +/- 1.7 mm and a mean CAL gain of 3.4 +/- 1.5 mm (p<0.001). The sites treated with GTR showed a mean PPD reduction of 4.2 +/- 1.9 mm and a mean CAL gain of 3.1 +/- 1.5 mm (p<0.001). The sites treated with the combined treatment showed a mean PPD reduction of 4.3 +/- 1.4 mm and a mean CAL gain of 3.4 +/- 1.1 mm (p<0.001). In the control group, the mean PPD reduction was 3.7 +/- 1.4 mm (p<0.001) and the mean CAL gain measured 1.7 +/- 1.5 mm (p<0.01). All 4 treatments led to statistically significant PPD reduction and CAL gain. All three regenerative treatments led to higher CAL gain than the control treatment (p<0.05). No statistical significant differences in PPD reduction and CAL gain were observed between the three regenerative treatments. CONCLUSION: It may be concluded that (a) all 3 regenerative treatment modalities may lead to higher CAL gain than the control one, and (b) the combined treatment does not seem to improve the outcome of the regenerative procedure.     

Treatment of gingival recession: comparative study between subepithelial connective tissue graft and guided tissue regeneration

BACKGROUND: Various procedures have been proposed to treat gingival recession, but few studies compare these procedures to each other. The purpose of this study was to evaluate a clinical comparison of subepithelial connective tissue graft (SCTG) and guided tissue regeneration (GTR) with a collagen membrane in the treatment of gingival recessions in humans. METHODS: Twenty-four defects were treated in 12 patients who presented canine or pre-molar Miller Class I and/or II bilateral gingival recessions. Both treatments were performed in all patients, and clinical measurements were obtained at baseline and 18 months after surgery. These clinical measurements included gingival recession height (GR), root coverage (RC), probing depth (PD), keratinized tissue width (KT), and final esthetic result. RESULTS: Both SCTG and GTR with a bioabsorbable membrane and bone graft demonstrated significant clinical and esthetic improvement for gingival recession coverage. The SCTG group was statistically significantly better than GTR for height of GR (SCTG = 0.2 mm, GTR = 1.12 mm, P= 0.02) and KT (SCTG = 4.58 mm, GTR = 2.5 mm, P<0.0001). However, PD was statistically significantly better for GTR than SCTG treatment (GTR = 1.66 mm, SCTG = 1.00, P= 0.01). The 2 procedures were statistically similar in root coverage (SCTG = 95.6%, GTR = 84.2%, P= 0.073). The esthetic condition after both treatments was satisfactory (P= 0.024). CONCLUSIONS: It was concluded that the gingival recessions treated with the SCTG group were superior for GR, RC, and KT clinical parameters, while GTR demonstrated better PD reduction. The final esthetic results were similar using both techniques.     

Intentional reim plantation of a tooth with severe periodontal involvement using enamel matrix derivative in combination with guided tissue regeneration and bone grafting: a case report

This case involved the intentional reimplantation of a tooth with severe periodontal involvement using regenerative therapies. The maxillary left central incisor was intentionally extracted, enamel matrix derivative (EMD) was applied, and the tooth was repositioned accurately. The bone defect was filled with a xenograft and a demineralized freeze-dried bone allograft, and a guided tissue regeneration membrane was adapted over the site. After 5 years, a reduction in probing depth and a gain in clinical attachment were observed. Conventional radiographs and cone-beam computerized tomographs showed hard tissue improvement. Favorable clinical results were obtained with reimplantation with applied EMD, combined with regenerative therapies, for treating a tooth with severe periodontal involvement.     

Enamel matrix derivative and guided tissue regeneration in the treatment of dehiscence-type defects: a histomorphometric study in dogs

BACKGROUND: The goal of this investigation was to histologically and histometrically evaluate the healing process of dehiscence-type defects treated by enamel matrix derivative (EMD) and/or guided tissue regeneration (GTR). METHODS: Seven mongrel dogs were used. Buccal osseous dehiscences were surgically created on the mesial roots of the mandibular third and fourth premolars. The defects were exposed to plaque accumulation for 3 months. After this period, the defects were randomly assigned to one of the treatments: open flap debridement (OFD), enamel matrix derivative (EMD), GTR with bioabsorbable membrane (GTR), and the combination of both procedures (EMD + GTR). After 4 months of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included gingival recession, epithelial length, connective tissue adaptation, new cementum, and new bone. RESULTS: A superior length of new cementum was observed in the sites treated by EMD (3.7 mm) and EMD + GTR (3.8 mm) in comparison with OFD (2.4 mm) (P < 0.05). No statistically significant differences were found in the remaining histometric parameters. CONCLUSIONS: Within the limits of this study, it can be concluded that EMD alone or in combination with GTR barriers may effectively promote new cementum formation. The combination of both therapies may not provide additional benefits.     

Experimental study of periodontal tissue regeneration after the application of enamel matrix derivative in rat periodontal defects

The purpose of this study was to evaluate periodontal wound-healing after the application of enamel matrix derivative (EMD) in rats. Periodontal defects were surgically created on the mesial side of the first maxillary molar of 24 male Long-Evans rats. EMD was applied to cover the denuded root surfaces in the experimental group. The contralateral molar was used for the control group, which received the same treatment without EMD. The rats were sacrificed at 2 weeks (8 rats), 4 weeks (8 rats), and 8 weeks (8 rats) after the surgery. Demineralized paraffin sections were stained with Masson's trichrome. Histological analysis and histomorphometric measurements were performed on the periodontal sections. Using an immunohistochemical technique, the localization of osteocalcin (OC) was also examined. The formation of new cementum was statistically significant in the experimental group, especially new cementum with extrinsic fiber. Both acellular and cellular cementum were also rather strongly observed in the experimental group. Epithelial down growth was also strongly inhibited in the experimental group at 8 weeks after the surgery. OC-positive cells and matrix were limited at the bottom of the defects in the control group, while positive reaction was detected not only at the bottom but also spreading to the coronal portion of the defects in the experimental group. These results suggest that EMD has potential to promote cementum regeneration, especially fiber-inserted cementum, and to create a favorable environment that will promote periodontal regeneration.