Periodontal regeneration with enamel matrix derivative in reconstructive periodontal therapy: a systematic review

The paradigm shifts of periodontal regeneration strategy: From reparative manipulation to developmental engineering

Ideal periodontal regeneration requires the integration of alveolar bone, periodontal ligament, and cementum, along with Sharpey's fibers for occlusal force resistance. However, physiological regeneration remains rare due to its intricate structure, making clinical regeneration a challenge. Periodontal ligament stem cells (PDLSCs), first isolated in 2004, hold the key to multi-directional differentiation into cementoblasts, fibroblasts, and osteoblasts. While traditional therapies like guided tissue regeneration (GTR) aim to activate PDLSCs, clinical outcomes are inconsistent, suggesting the need for additional strategies to enhance PDLSCs' functions. Advancements in molecular biotechnology have introduced the use of recombinant growth factors for tissue regeneration. However, maintaining their efficacy requires high doses, posing cost and safety issues. Multi-layered scaffolds combined with cell sheet technology offer new insights, but face production, ethical, and survival challenges. Immune regulation plays a crucial role in PDLSC-mediated regeneration. The concept of "coagulo-immunomodulation" has emerged, emphasizing the coupling of blood coagulation and immune responses for periodontal regeneration. Despite its potential, the clinical translation of immune-based strategies remains elusive. The "developmental engineering" approach, which mimics developmental events using embryonic-stage cells and microenvironments, shows promise. Our research group has made initial strides, indicating its potential as a viable solution for periodontal complex regeneration. However, further clinical trials and considerations are needed for successful clinical application. This review aims to summarize the strategic transitions in the development of periodontal regenerative materials and to propose prospective avenues for future development.

Bony Defect Regeneration in Periodontitis: A Systematic Review of the Literature Regarding the Use of Enamel Matrix Derivative Proteins

Background: Periodontitis is characterized as a change in the total periodontal tissues that includes tissue loss, as evidenced by clinical loss of attachment, and radiographically determined alveolar bone loss, periodontal pockets, and gingival bleeding. Objectives: The aim of this study was to observe and analyze recent information from the literature on the effect of enamel matrix derivative proteins on the bony defects caused by periodontitis. Methods: Through using two major online databases and search engines, the literature was manually searched for papers published until May 2024. To find relevant studies, this research utilized a combination of target keywords, and the reference lists of manuscripts that were chosen for inclusion in this study were checked and analyzed in tabular form, enabling the collection and comparison of data. Results: According to the results, the average value of the probing depth gained was 4 mm for the EMD™ alone and 4.25 mm for the EMD combined with surgical techniques such as open-flap techniques, platelet derivatives, and growth factors. In regard to clinical attachment level (CAL) gaining, average values of 3.6 mm in EMD™ alone and 3.86 mm with EMD™ combined with other techniques were observed. Conclusions: It can be concluded that the healing propensity depends on the morphological structure of the bone defect represented by the wall stage, and there is a certain coherence and correlation between the values of probing depth (PD) and clinical attachment level (CAL), whether for the use of EMD alone or its use in combination with other materials.

Treatment of Localized Gingival Recession with an Enamel Matrix Protein-Coated Xenogeneic Dermal Matrix: A Randomized Controlled Trial

This study aims to evaluate the influence of the additional use of enamel matrix derivate (EMD) in the treatment of gingival recession defects using a coronally advanced flap (CAF) and a xenogeneic dermal matrix (XDM) by means of digital and clinical assessment methods. In this prospective randomized controlled study, recession height and area, width and thickness of keratinized gingiva, pocket probing depth, and clinical attachment levels were measured at the baseline and followed up for one year. Fifteen patients (n = 15) with 24 gingival recession defects were treated between 2019 and 2021. On average, the digitally assessed root coverage of the control group (CAF + XDM) was not significantly different compared to the test group (CAF + XDM + EMD), with 69 ± 28% and 36 ± 32%, respectively (p = 0.094). One year postoperatively, there were no differences found regarding keratinized tissue width (KTW) between the control group and test group (p = 0.690). However, the control group showed superior results in the thickness of keratinized gingiva (p = 0.044). The present study showed that there were no statistically significant differences in the root coverage results in the CAF + XDM + EMD group compared to the CAF + XDM group. The adjunctive use of EMD to a CAF and XDM in the treatment of gingival recession defects does not appear to have any clinical benefit.

A Novel and Minimally Invasive Approach Using the Root and Cervical Margin Flattening Procedure for Treating Gingival Recession: A Report of Four Cases

Traditional plastic surgery techniques for root coverage using connective tissue grafts are often invasive and cause patient discomfort. A new procedure with a minimally invasive approach for gingival recession was developed and termed the "root and cervical margin flattening procedure." A blunt incision was performed in the buccal gingival sulcus at the alveolar bone crest with a dissector or raspatory. After the incision, a split-thickness flap was dissected extending beyond the mucogingival junction, palpating the alveolar bone crest with a periodontal probe and flattening the cervical region and roots to smooth out irregularities along the dental root. In some complicated cases, more reliable effects were expected using a periodontal tissue regeneration drug and protective splint. The creeping attachment distance reached the flattened area. Careful blood clot preservation was crucial in the postoperative period. The gingival creeping attachment implied two main factors. First, surgical invasion could promote healing. Second, soft tissue space was increased due to root flattening. This simple and minimally invasive approach for treating cervical lesions (including non-carious cervical lesions and cervical/root caries) and gingival recession could obviate the need for connective tissue grafts. Further clinical studies are required to assess its success and prognosis.

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

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

Enamel Matrix Derivative (EMD) as an Adjunct to Non-surgical Periodontal Therapy: A Systematic Review

If left untreated, periodontitis is a chronic, irreversible disease that can contribute to tooth loss. The primary objective of periodontal treatment is to arrest the progression of the disease and restore the supporting structures of the tooth. Scaling and root planing (SRP) is a common non-surgical periodontal therapy (NSPT) used to reduce inflammation, pocket depth, and clinical attachment loss. However, NSPT has limitations, notably in difficult-to-access deep pockets and molar furcations. Deep pockets (greater than 4 mm) frequently retain calculus following NSPT. To attain direct access, surgical periodontal therapy (SPT) is recommended, particularly for pockets deeper than 5 mm. Enamel matrix derivative (EMD) has emerged in recent years as a tool for periodontal regeneration when used in conjunction with NSP for infrabony defects. EMD may also have advantageous effects when combined with NSPT. The purpose of this review is to provide a thorough understanding of the effects of EMD as an adjunct to NSPT. The databases Scopus, PubMed/MEDLINE, Google Scholar, Cochrane, and Embase were systematically searched to identify relevant studies on the benefits of EMD and its use as an adjunct to NSPT. Incorporating EMD into NSPT reduces chair time, and 60% of studies demonstrated considerable benefits compared to SRP alone, according to the findings. On the basis of research, it can be concluded that EMD can be used as an adjunct to NSPT, thereby reducing the amount of time spent in the operating chair. In some cases, it can, therefore, be regarded as an alternative to surgical treatment.

The influence of interradicular anatomy on the predictability of periodontal regenerative therapy of furcation defects: a retrospective, multicenter clinical study

BACKGROUND

The relationship between the anatomy of the interradicular space and success in regenerative therapy of furcation defects is discussed in this paper. The goal of this retrospective, multicenter clinical study is to clinically evaluate the relationship between the interradicular conformation and regenerative therapy success with the use of a novel measurement method.

METHODS

One hundred thirty-eight radiographs of mandibular molars with furcation defects that had been treated with regenerative therapy were collected from six clinical centers. Data on the type of therapy and clinical parameters before and after treatment (follow-up of at least 12 months) were collected. The radiographs (before surgery and at least 12 months postoperatively) were measured with a visual evaluation method by a blind operator using graphics software.

RESULTS

Success, defined as a reduction in horizontal and vertical furcation involvement, decrease in probing depths, and increase in clinical attachment level, was statistically assessed on 138 regenerated molars sites and were related to clinical variables such as age, sex, center, and treatment. No correlation was found between success in regenerative therapy and the conformation of the interradicular space, measured with a visual ratio method and a standard linear measurement. At the univariate analysis, the parameters that had a correlation with success were center, extent of furcation involvement, treatment, and sex. The use of enamel matrix derivative (EMD) seemed to be the most favorable therapy, with increase in CAL gain and reduction of vertical or horizontal furcation involvement.

CONCLUSIONS

The regenerative outcome was not significantly influenced by the anatomy of furcation. The center, the degree of furcation involvement, sex, and treatment (EMD) were significantly associated with higher success of periodontal regeneration.

Regenerative Potential of Bone Morphogenetic Protein 7-Engineered Mesenchymal Stem Cells in Ligature-Induced Periodontitis

Periodontitis is an oral disease caused by bacterial infection that has stages according to the severity of tissue destruction. The advanced stage of periodontitis presents irreversible destruction of soft and hard tissues, which finally results in loss of teeth. When conventional treatment modalities show limited results, tissue regeneration therapy is required in patients with advanced periodontitis. In the present study, we aimed to evaluate the effect of bone marrow-derived mesenchymal stem cells (BM-MSCs) delivering bone morphogenetic protein 7 (BMP7) on tissue regeneration in a periodontitis model. BMP7 is a member of the BMP family that shows bone-forming ability; however, BMPs rapid clearing and degradation and unproven efficacy make it difficult to apply it in clinical dentistry. To overcome this, we established BMP7-expressing engineered BM-MSCs (BMP7-eBMSCs) that showed superior osteogenic differentiation potential when subcutaneously transplanted with a biphasic calcium phosphate scaffold into immunocompromised mice. Furthermore, the efficacy of BMP7-eBMSC transplantation for periodontal tissue regeneration was evaluated in a rat ligature-induced periodontitis model. Upon measuring two-dimensional and three-dimensional amounts of regenerated alveolar bone using microcomputed tomography, the amounts were found to be significantly higher in the BMP7-eBMSC transplantation group than in the eBMSC transplantation group. Most importantly, fibrous periodontal ligament (PDL) tissue regeneration was also achieved upon BMP7-eBMSC transplantation, which was evaluated by calculating the modified relative connective tissue attachment. The amount of connective tissue attachment in the BMP7-eBMSC transplantation group was significantly higher than that in the ligature-induced periodontitis group, although the increase was comparable between the BMP7-eBMSC and human PDL stem cell transplantation groups. Taken together, our results suggested that sustainable release of BMP7 induces periodontal tissue regeneration and that transplantation of BMP7-eBMSCs is a feasible treatment option for periodontal regeneration. Impact Statement Periodontitis is the second most common human dental disease affecting chronic systemic diseases. Despite the tremendous efforts trying to cure the damaged periodontal tissues using tissue engineering technologies, a definitive regenerative method has not been in consensus. Researchers are seeking more feasible and abundant source of mesenchymal stem cells (MSCs), and furthermore, how to use reliable growth factors under more efficient control are the issues to be solved. In this study, we aimed to evaluate the effect of bone morphogenetic protein 7 (BMP7) gene delivering bone marrow-derived MSCs on periodontal tissue regeneration to evaluate the efficacy of BMP7 and engineered BMSCs for periodontal tissue regeneration.

Radiographic ratios for classifying furcation anatomy: proposal of a new evaluation method and an intra-rater and inter-rater operator reliability study

OBJECTIVES

Even if it seems to be an important anatomical parameter for tissue regeneration, few studies in literature evaluate the "mean measure" of root divergence. Most of them are linear measurements, which hardly describe the dental furcation conformation in its entirety. It is left to the subjectivity of the operator deciding whether a furcation is convergent or divergent. The goal of this study is to create a visual evaluation method using specific measurements applied on endo-oral X-rays to overcome these problems, giving a conformation of the entire interradicular space and its divergence.

MATERIAL AND METHODS

A user-friendly software (Paint®, Windows10®) was used to take three different measurements on endo-oral radiographs of upper and lower molars. Three blind operators measured 20 radiographs, to analyze the intra- and inter-operator reproducibility of the measurements. Then, the technique was repeated on 250 radiographic images to identify an average value and define a main conformation of the interradicular space. The ratio of these three measurements allowed to develop a new visual evaluation method of the interradicular space.

RESULTS

Intra and inter-operator reproducibility was statistically confirmed on a sample of 20 anonymous endo-oral radiographs measured by 3 blind operators, indicating that the measurement technique was not operator dependent. Measurement made on 250 X-rays obtained with this technique permitted to subdivide in five groups the conformation of the interradicular space and define a mean value of the interradicular space.

CONCLUSIONS

A new anatomical evaluation of the interradicular space in its entirety, which could help the clinicians in diagnostic and decisional phase in the therapy of furcated molars, can be obtained.

CLINICAL RELEVANCE

A pre-operative evaluation of interradicular space conformation could affect therapy treatment choice.

Abaloparatide outperforms teriparatide in protecting against alveolar bone loss in experimental periodontitis

BACKGROUND

The aim of this study was to compare the effects of two osteoanabolic drugs, abaloparatide (ABL) and teriparatide (TPTD), on protecting alveolar bone in experimental periodontitis.

METHODS

Twenty-four 9-week-old, male, Sprague-Dawley rats were placed with silk suture around the right maxillary second molar, and then were randomly divided into three groups, that is, the ABL, TPTD, and saline group, receiving intermittent subcutaneous injections of ABL (80 μg/kg), TPTD (80 μg/kg) or saline respectively every other day for 4 weeks. Samples on both sides were assessed through micro-computerized tomography, histological, and immunohistochemical analysis. Mouse pre-osteoblast MC3T3 cell was cultured with lipopolysaccharide (LPS) and treated with ABL or TPTD, before assays of cell proliferation, alkaline phosphatase (ALP) activity and real-time polymerase chain reaction.

RESULTS

On the ligature side, both ABL and TPTD significantly reduced alveolar bone loss, and ABL had significantly better effects with higher expression of runt-related transcription factor 2 (RUNX2) and Bglap (formerly called osteocalcin); meanwhile, the ligature induced osteoclastogenesis and down-regulation of osteoprotegerin (OPG) was affected by neither drug. On the non-ligature side, ABL also showed better osteoanabolic effects. In vitro studies revealed that, in the presence of LPS, ABL, and TPTD similarly promoted MC3T3 proliferation, whereas ABL induced higher ALP activity and osteoblastic gene expression compared to TPTD.

CONCLUSION

Both ABL and TPTD protect and regenerate alveolar bone in experimental periodontitis, and ABL behaves even better than TPTD at the same dose, attributed to its stronger osteoanabolic effects in this context.

Minimal invasiveness in the surgical treatment of intraosseous defects: A systematic review

The modern approach to regenerative treatment of periodontal intraosseous defects should aim at maximizing the clinical outcomes while minimizing the invasiveness (pain, complications, aesthetic impairment, chair time, and costs) of the procedure. The present systematic review evaluated the effect of flap design, regenerative technology, and perioperative and postoperative adjunctive protocols on invasiveness. Overall, the results of the 13 included trials indicate that: (a) the elevation of a single (buccal or lingual) flap positively influences the intensity of postoperative pain and improves the quality of early wound healing compared with double flaps; (b) while the adjunctive use of a membrane is associated with significantly longer surgery-related chair time and higher postoperative pain, the adjunctive use of enamel matrix derivative at sites receiving a graft significantly reduces postoperative pain; also, graft materials showed no significant impact on invasiveness; (c) open flap debridement performed through the elevation of a single flap may lead to substantial clinical improvements of the lesion with reduced surgery-related chair time and costs, thus representing a promising alternative to regenerative treatment. However, for such an approach, a histological evaluation of the nature of the reconstructed tissues is still lacking, and the presurgery conditions (eg, probing depth, defect severity, and defect morphology), which may benefit in terms of invasiveness, have not yet been defined; and (d) intraoperative and postoperative low-level laser biostimulation of the defect site may favorably modulate the postoperative course.

Minimally Invasive Non-Surgical Technique in the Treatment of Intrabony Defects-A Narrative Review

Intrabony defects occur frequently in periodontitis and represent sites that, if left untreated, are at increased risk for disease progression. Although resective or repair procedures have been used to treat intrabony defects, aiming at their elimination, the treatment of choice is surgical periodontal regeneration. The development of periodontal regeneration in the last 30 years has followed two distinctive, though totally different, paths. The interest of researchers has so far focused on regenerative materials and products on one side, and on novel surgical approaches on the other side. In the area of materials and products, three different regenerative concepts have been explored namely, barrier membranes, bone grafts, and wound healing modifiers/biologics, plus many combinations of the aforementioned. In the area of surgical approaches, clinical innovation in flap design and handling, as well as minimally invasive approaches, has radically changed regenerative surgery. Recently, a minimally invasive non-surgical technique (MINST) for the treatment of intrabony defects was proposed. Initial clinical trials indicated comparable results to the surgical minimally invasive techniques in both clinical and radiographic outcomes. These results support the efficacy of this treatment approach. The aim of this review is to present the evidence on the application of minimally invasive non-surgical techniques and their efficacy in the treatment of intrabony defects.

The efficiency of the regeneration of periodontal intrabony defects in East Asians: A systematic review and pooled analysis

This article aimed to assess the efficacy of periodontal regenerative therapy (PRT) for treating periodontal intrabony defects in East Asians. The systematic review was performed according to the PRISMA guidelines. Literature searches on the PubMed and national medical journal databases, and representative clinical journals of the East Asians were performed on July 31, 2018. Randomized controlled trials, prospective case-control studies, retrospective analyses, and case series receiving regenerative procedures, including barrier membrane (BM) and enamel matrix derivative (EMD) applications with or without bone replacement graft (BRG), with follow-up periods of 6 and 12 months were evaluated. The outcome variables were probing depth (PD) reduction and clinical attachment level (CAL) gain. Twenty studies were included, of which eight were assessed for bias risk. Compared to open flap debridement, PD reduction and CAL gain were superior in all PRTs at both follow-up time points. BM or EMD alone showed equivalent outcomes at 6 months, and CAL gain appeared greater with BM alone at 12 months. BM with BRG showed inferior CAL gain relative to BM alone, but EMD with BRG showed superior CAL gain relative to EMD alone at 12 months. In conclusion, PRT showed improved regenerative outcomes compared with OFD in East Asians, while BM application appeared less efficient than in non-East Asians. BRG supplementation provided additional clinical benefits in EMD application.

An exploratory clinical trial to evaluate the safety and efficacy of combination therapy of REGROTH® and Cytrans® granules for severe periodontitis with intrabony defects

Introduction

Currently, flap operation (FOP) using REGROTH® (0.3% basic fibroblast growth factor [FGF-2]) is the standard treatment for periodontal regenerative therapy in Japan. However, the periodontal tissue regenerative effect with REGROTH® monotherapy is inadequate for severe alveolar bone defects. Therefore, in this study, we evaluated the safety and effectiveness of periodontal regenerative therapy for patients with severe periodontitis using REGROTH® (test medicine) combined with Cytrans® Granules (test device: carbonated apatite granules), which is a new artificial bone.

Methods

The study participants included 10 patients with severe periodontitis (mean age: 47.4 years). All participants provided written informed consents. In each patient, the intrabony defect site (mean bone defect depth: 5.7 mm) was defined as the test site. FOP was performed for the test site after the baseline investigation; moreover, the test medicine and test device were administered simultaneously. Furthermore, the observation of subjects’ general condition and test sites was conducted and the blood, urine, and periodontal tissue tests were performed up to 36 weeks after FOP. The rate of bone increase (%), clinical attachment level (CAL), probing pocket depth (PPD), bleeding on probing (BOP), tooth mobility (Mo), width of keratinized gingiva (KG), gingival recession (REC), gingival index (GI), and plaque index (PlI) were evaluated during the periodontal tissue investigation.

Results

As the primary endpoint, no adverse events related to the test medicine and test device occurred during the entire observation period of this study. Regarding the secondary endpoints, there was a significant increase in new alveolar bone (p = 0.003) and CAL acquisition (p = 0.001) as well as decrease in PPD (p = 0.002) and BOP (p = 0.016) at 36 weeks after administration of the test medicine and test device compared with the preoperative values. Furthermore, at 36 weeks after surgery, the Mo, GI, and PlI decreased to preoperative levels at 40%, 60%, and 30% of sites, respectively. However, at 36 weeks after surgery, there was no difference in KG and REC compared with their preoperative values.

Conclusions

The safety of periodontal regenerative therapy using the test medicine in combination with the abovementioned test device was confirmed. In addition, it was suggested that this periodontal regenerative therapy is effective for tissue regeneration in severe alveolar bone defects.

This clinical trial was conducted after registering and publicizing as a specified clinical trial in the Japan registry of clinical trials (jRCTs051190045).

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The safety of flap operation using 0.3% FGF-2 and carbonated apatite was confirmed.

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The administration of 0.3% FGF-2 and carbonated apatite improved periodontitis.

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Combining 0.3% FGF-2 and carbonated apatite for severe alveolar bone defects.

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Periodontal regenerative therapy combining both could be effective.

Human Umbilical Cord Mesenchymal Stem Cells: Current Literature and Role in Periodontal Regeneration

Periodontal disease can cause irreversible damage to tooth-supporting tissues such as the root cementum, periodontal ligament, and alveolar bone, eventually leading to tooth loss. While standard periodontal treatments are usually helpful in reducing disease progression, they cannot repair or replace lost periodontal tissue. Periodontal regeneration has been demonstrated to be beneficial in treating intraosseous and furcation defects to varied degrees. Cell-based treatment for periodontal regeneration will become more efficient and predictable as tissue engineering and progenitor cell biology advance, surpassing the limitations of present therapeutic techniques. Stem cells are undifferentiated cells with the ability to self-renew and differentiate into several cell types when stimulated. Mesenchymal stem cells (MSCs) have been tested for periodontal regeneration in vitro and in humans, with promising results. Human umbilical cord mesenchymal stem cells (UC-MSCs) possess a great regenerative and therapeutic potential. Their added benefits comprise ease of collection, endless source of stem cells, less immunorejection, and affordability. Further, their collection does not include the concerns associated with human embryonic stem cells. The purpose of this review is to address the most recent findings about periodontal regenerative mechanisms, different stem cells accessible for periodontal regeneration, and UC-MSCs and their involvement in periodontal regeneration.

P4 Medicine as a model for precision periodontal care

Objectives

P4 Medicine is based on a proactive approach for clinical patient care incorporating the four “pillars” of prediction, prevention, personalization, and participation for patient management. The purpose of this review is to demonstrate how the concepts of P4 medicine can be incorporated into the management of periodontal diseases (particularly periodontitis) termed P4 periodontics.

Methods

This is a narrative review that used current literature to explore how P4 periodontics can be aligned with the 2018 Classification of Periodontal Diseases, current periodontal treatment paradigms, and periodontal regenerative technologies.

Results

The proposed model of P4 periodontics is highly aligned with the 2018 Classification of Periodontal Diseases and represents a logical extension of this classification into treatment paradigms. Each stage of periodontitis can be related to a holistic approach to clinical management. The role of “big data” in future P4 periodontics is discussed and the concepts of a treat-to-target focus for treatment outcomes are proposed as part of personalized periodontics. Personalized regenerative and rejuvenative periodontal therapies will refocus our thinking from risk management to regenerative solutions to manage the effects of disease and aging.

Conclusions

P4 Periodontics allows us to focus not only on early prevention and intervention but also allow for personalized late-stage reversal of the disease trajectory and the use of personalized regenerative procedures to reconstruct damaged tissues and restore them to health.

Clinical Significance

P4 Periodontics is a novel means of viewing a holistic, integrative, and proactive approach to periodontal treatment.

Links between Insulin Resistance and Periodontal Bacteria: Insights on Molecular Players and Therapeutic Potential of Polyphenols

Type 2 diabetes is a metabolic disease mainly associated with insulin resistance during obesity and constitutes a major public health problem worldwide. A strong link has been established between type 2 diabetes and periodontitis, an infectious dental disease characterized by chronic inflammation and destruction of the tooth-supporting tissue or periodontium. However, the molecular mechanisms linking periodontal bacteria and insulin resistance remain poorly elucidated. This study aims to summarize the mechanisms possibly involved based on in vivo and in vitro studies and targets them for innovative therapies. Indeed, during periodontitis, inflammatory lesions of the periodontal tissue may allow periodontal bacteria to disseminate into the bloodstream and reach tissues, including adipose tissue and skeletal muscles that store glucose in response to insulin. Locally, periodontal bacteria and their components, such as lipopolysaccharides and gingipains, may deregulate inflammatory pathways, altering the production of pro-inflammatory cytokines/chemokines. Moreover, periodontal bacteria may promote ROS overproduction via downregulation of the enzymatic antioxidant defense system, leading to oxidative stress. Crosstalk between players of inflammation and oxidative stress contributes to disruption of the insulin signaling pathway and promotes insulin resistance. In parallel, periodontal bacteria alter glucose and lipid metabolism in the liver and deregulate insulin production by pancreatic β-cells, contributing to hyperglycemia. Interestingly, therapeutic management of periodontitis reduces systemic inflammation markers and ameliorates insulin sensitivity in type 2 diabetic patients. Of note, plant polyphenols exert anti-inflammatory and antioxidant activities as well as insulin-sensitizing and anti-bacterial actions. Thus, polyphenol-based therapies are of high interest for helping to counteract the deleterious effects of periodontal bacteria and improve insulin resistance.

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

OBJECTIVES

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

METHODOLOGY

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

RESULTS

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

CONCLUSION

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

Nanocrystalline hydroxyapatite in regeneration of periodontal intrabony defects: A systematic review and meta-analysis

BACKGROUND

Alveolar bone loss and mobility of teeth is commonly observed in periodontitis patients. Regeneration of periodontal intrabony defects is indicated to restore the lost bone and periodontal tissues. The aim of the present study was to evaluate the clinical outcomes of periodontal intrabony lesions by using nanocrystalline hydroxyapatite (NHA) graft and comparing it with open flap debridement (OFD) alone.

MATERIALS AND METHODS

The eligibility criteria encompassed randomized (RCTs) and controlled clinical trials (CCTs). Weighted mean differences were calculated for clinical attachment level (CAL) gain, probing pocket depth (PPD) reduction and gingival recession (REC) change, demonstrated as forest plots. The revised Cochrane Risk of Bias tool for randomized trials (RoB2) and Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool were used for quality assessment of RCTs and non-randomized trials respectively.

RESULTS

From 22 full-text articles identified, three RCTs, one CCT and one retrospective follow-up of RCT were included. All the five papers comprised the quantitative evaluation. The use of NHA graft provided additional CAL gain of 0.96 mm (p = 0.0009) and PPD reduction of 0.97 mm (p < 0.00001) when compared to OFD alone. However, in terms of REC changes, no considerable benefits of NHA graft were demonstrated than OFD alone (p = 0.48).

CONCLUSIONS

The bioactive NHA graft showed promising results clinically in regenerative periodontology and can be considered for the management of periodontal intrabony defects. The use of NHA graft considerably provided better clinical outcomes in intrabony defects compared to using the OFD alone. Future research investigating NHA graft against other regenerative materials including specific BGs, at longer follow-up periods and bigger sample sizes and in furcation defects warranted.

Advanced non-fluoride approaches to dental enamel remineralization: The next level in enamel repair management

In modern dentistry, a minimally invasive management of early caries lesions or early-stage erosive tooth wear (ETW) with synthetic remineralization systems has become indispensable. In addition to fluoride, which is still the non-plus-ultra in these early caries/ETW treatments, a number of new developments are in the test phase or have already been commercialized. Some of these systems claim that they are comparable or even superior to fluoride in terms of their ability to remineralize enamel. Besides, their use can help avoid some of the risks associated with fluoride and support treatments of patients with a high risk of caries. Two individual non-fluoride systems can be distinguished; intrinsic and extrinsic remineralization approaches. Intrinsic (protein/peptide) systems adsorb to hydroxyapatite crystals/organics located within enamel prisms and accumulate endogenous calcium and phosphate ions from saliva, which ultimately leads to the re-growth of enamel crystals. Extrinsic remineralization systems function on the basis of the external (non-saliva) supply of calcium and phosphate to the crystals to be re-grown. This article, following an introduction into enamel (re)mineralization and fluoride-assisted remineralization, discusses the requirements for non-fluoride remineralization systems, particularly their mechanisms and challenges, and summarizes the findings that underpin the most promising advances in enamel remineralization therapy.

Current Concepts in the Management of Periodontitis

Periodontitis is a common disorder affecting >40% of adults in the United States. Globally, the severe form of the disease has a prevalence of 11%. In advanced cases, periodontitis leads to tooth loss and reduced quality of life. The aetiology of periodontitis is multifactorial. Subgingival dental biofilm elicits a host inflammatory and immune response, ultimately leading to irreversible destruction of the periodontium (i.e. alveolar bone and periodontal ligament) in a susceptible host. In order to successfully manage periodontitis, dental professionals must understand the pathogenesis, primary aetiology, risk factors, contributing factors and treatment protocols. Careful diagnosis, elimination of the causes and reduction of modifiable risk factors are paramount for successful prevention and treatment of periodontitis. Initial non-surgical periodontal therapy primarily consists of home care review and scaling and root planing. For residual sites with active periodontitis at periodontal re-evaluation, a contemporary regenerative or traditional resective surgical therapy can be utilised. Thereafter, periodontal maintenance therapy at a regular interval and long-term follow-ups are also crucial to the success of the treatment and long-term retention of teeth. The aim of this review is to provide current concepts of diagnosis, prevention and treatment of periodontitis. Both clinical and biological rationales will be discussed.

Decontamination and Biomodification of Periodontally Affected Root Surface for Successful Regeneration: Is There Room for Improvement?

Periodontitis is a multifactorial inflammatory condition associated with an oral microbiome dysbiosis that results in gingival inflammation and clinical attachment loss. Periodontal therapies are based on scaling and root planing to disturb the bacterial biofilm mechanically and remove calculus and contaminated cementum. Research does not support the use of root modifiers for decontamination and biomodification of periodontally affected root surfaces. Standardized clinical trials in large populations, assessing biological and patient-reported outcome measures, are necessary to evaluate candidate biomaterials for decontamination and biomodification of periodontally affected root surfaces.

Soft Tissue Regeneration at Natural Teeth

This article provides an overview of the best-documented surgical techniques for recession coverage and draws conclusions for the clinician. Use of a connective tissue graft with either coronally advanced flap (CAF) or tunnel is the most predictable technique for the treatment of single and multiple gingival recessions. Long-term results exist only for CAF with/without connective tissue graft providing evidence for long-term stability with only minor relapses. Soft tissue replacement materials and biologics may represent a valuable modality to additionally improve the clinical outcomes obtained with CAF alone or, in certain clinical situations, to serve as an alternative to autogenous tissue.

Comparing Nanohydroxyapatite Graft and Other Bone Grafts in the Repair of Periodontal Infrabony Lesions: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare the results of periodontal infrabony lesions treated using nanohydroxyapatite (NcHA) graft with other bone grafts (BGs).

METHODS

Four electronic databases were searched including PubMed (NLM), Embase (Ovid), Medline, and Dentistry and Oral Sciences (EBSCO). The inclusion criteria included randomised controlled clinical trials (RCTs) and controlled clinical trials (CCTs). The clinical results of NcHA were compared with other BGs. For clinical attachment level (CAL) gain, probing pocket depth (PPD) decrease, and gingival recession (REC) change, weighted averages and forest plots were computed.

RESULTS

Seven RCTs fulfilled the selection criteria that were included. When NcHA was compared to other BGs, no clinically significant differences were found in terms of each outcome assessed, except the REC change for synthetic BGs as compared to NcHA.

CONCLUSIONS

The use of an NcHA graft showed equivalent results compared to other types of BGs. To further validate these findings, future studies are required to compare the NcHA and various BGs over longer time periods and in furcation deficiencies.

Enamel matrix derivative as an adjunct to minimally invasive non-surgical treatment of intrabony defects: A randomized clinical trial

AIM

To compare the efficacy of minimally invasive non-surgical technique (MINST) with or without enamel matrix derivative (EMD) in the treatment of intrabony defects ≤7 mm.

MATERIALS AND METHODS

Thirty-six patients were randomly assigned to the two groups. The control group received MINST, while the experimental MINST+EMD. Clinical measurements were recorded at baseline and at 6 and 12 months, and radiographic measurements were made at baseline and 12 months.

RESULTS

All subjects completed the study, 18 in each group. Significant improvements were observed in both groups at 12 months (p < .001) with no differences in mean PD reduction (4.0 ± 1.4 vs. 4.2 ± 1.7 mm), CAL gain (3.5 ± 1.4 vs. 3.4 ± 1.6 mm), and defect resolution (1.9 ± 1.1 vs. 1.8 ± 0.9 mm) for the MINST and the MINST+EMD groups, respectively (p > .05). A trend for greater pocket closure (PD ≤4 mm and no BoP) was achieved with the application of EMD (77.8% vs. 55.6% sites), particularly for sites with baseline PD ≤8 mm (92.3% vs. 69.2% sites), accompanied by an increased number of successful composite outcome results (61.1% vs. 44.4% sites).

CONCLUSIONS

MINST demonstrates significant improvements 12 months after treatment of intrabony defects ≤7 mm. The additional application of EMD does not further improve the mean clinical or radiographic outcomes. This study is registered in ClinicalTrials.gov (NCT03622255).

Treatment of intrabony periodontal defects in controlled diabetic patients with an enamel matrix derivative: a split-mouth randomized clinical trial

OBJECTIVE

This split-mouth randomized controlled trial aimed to evaluate the effect of enamel matrix derivative (EMD) associated with a simplified papilla preservation flap (SPPF) compared to SPPF alone in the surgical treatment of intrabony defects (ID) in type 2 diabetic mellitus (T2DM) patients.

MATERIAL AND METHODS

Thirteen patients with controlled T2DM presenting with ID in at least two quadrants were included. In each patient, the test site (TS) was treated with SPPF plus EMD, whereas the control site (CS) was treated only with SPPF. Prior to surgery and at 6 months after intervention, the following parameters were evaluated: clinical attachment level (CAL), probing pocket depth (PPD), and gingival recession (GR).

RESULTS

The TS and CS demonstrated a mean CAL gain of 3.31 ± 0.96 mm and 1.61 ± 1.12 mm, and a PPD reduction from 8.15 ± 0.98 to 3.00 ± 0.57 mm and 7.53 ± 0.96 to 4.69 ± 0.63 mm after 6 months, respectively. In both sites, the mean CAL gain and PPD reduction improved significantly after 6 months compared to baseline; however, the improvement was higher in the TS (p < 0.001).

CONCLUSIONS

Both surgical procedures presented with clinical improvements in controlled T2DM patients. However, the additional use of EMD showed enhanced clinical results after 6 months with regard to CAL gain and PPD reduction.

CLINICAL RELEVANCE

This study showed a better PPD reduction and CAL gain when an EMD was applied in addition to SPPF. Therefore, EMD may be used to enhance clinical outcomes in periodontal ID of controlled T2DM patients.

Periodontal regeneration: is it still a goal in clinical periodontology?

In the last decades, Periodontal Regeneration has been one of the most discussed topics in Periodontics, attracting the attention of researchers and clinicians. This can be justified by the evident and continuous progress observed in the field, characterized by a better understanding of the biological mechanisms involved, significant improvement of operative and technical principles, and the emergence of a wide range of biomaterials available for this purpose. Together, these aspects put the theme much in evidence in the search for functional and esthetic therapeutic solutions for periodontal tissue destruction. Despite the evident evolution, periodontal regeneration may be challenging and require the clinician to carefully evaluate each case before making a therapeutic decision. With a critical reassessment of the clinical and preclinical literature, the present study aimed to discuss the topic to answer whether Periodontal Regeneration is still a goal in clinical periodontology. The main aspects involved in the probability of success or failure of regenerative approaches were considered. A greater focus was given to intrabony and furcation defects, clinical conditions with greater therapeutic predictability. Aspects such as more appropriate materials/approaches, long-term benefits and their justification for a higher initial cost were discussed for each condition. In general, deep intrabony defects associated with residual pockets and buccal/lingual class II furcation lesions have predictable and clinically relevant results. Careful selection of the case (based on patient and defect characteristics) and excellent maintenance are essential conditions to ensure initial and long-term success.

Gingival recession treatment with enamel matrix derivative associated with coronally advanced flap and subepithelial connective tissue graft: a split-mouth randomized controlled clinical trial with molecular evaluation

OBJECTIVES

The goal of this study was to evaluate the impact of enamel matrix derivative (EMD) on periodontal healing after root coverage (RC) surgery, involving CAF in combination with SCTG, and to assess the molecular profile, verifying the inflammation level in early stage (1 and 2 weeks).

MATERIALS AND METHODS

Thirty-two recessions (RT1) were submitted to periodontal surgery with (test) or without (control) EMD. The clinical parameters analyzed on the day of surgery and 6 months after the surgical procedure were as follows: recession height and width, keratinized tissue height, percentual root coverage, and the gingival thickness of keratinized tissue. Moreover, the main inflammatory biomarkers and growth factors (IL-1β, IL-6, IL-8, FGF, MIP-1α and β, PDGF, TNF-α, and VEGF) were evaluated at baseline, 7, and 14 days after procedures.

RESULTS

The average root coverage was significantly higher in the test group as compared to the control group (86% vs. 66%, p = 0.008). The test side had significantly lesser final RH compared to the control side (p = 0.01). Also, there was a significant reduction of RW in both groups, with more significant results in the test group. KTH and GT were not significantly different at any time and group. After 14 days, the immunological analysis showed an increase of VEGF (p = 0.03) on the test group compared to the control side.

CONCLUSION

The use of EMD in RC surgeries resulted in a significantly higher RC, as well as a significant increase in VEGF expression, suggesting that EMD may contribute to the angiogenic and healing process.

CLINICAL RELEVANCE

EMD provided better results in root coverage treatment when associated with CAF and SCTG, beyond a greater releasing of angiogenic growth factor (VEGF), which enhanced the result.

Long-term clinical outcomes of periodontal regeneration with Enamel Matrix Derivative (EMD): a retrospective cohort study with a mean follow-up of 10 years

BACKGROUND

Despite the large body of evidence on the efficacy of Enamel Matrix Derivative (EMD) in the treatment of periodontal intrabony defects, few studies reported long-term data (≥ 10-year).

METHODS

Periodontal patients treated with regenerative surgery with EMD between 1999 and 2012 were invited to participate in a clinical examination. The following clinical parameters were recorded and compared at baseline (T0), 6 months after surgery (T1) and after at least 8 years of follow-up (T2): probing depth (PD), gingival recession (GR), clinical attachment level (CAL), plaque and bleeding scores. The primary outcome variable was CAL change.

RESULTS

Forty-one patients with 75 treated teeth were available for analysis. Out of these, 68 (tooth survival rate: 90.7%) reached the latest follow-up with a mean observation period of 10.3 years (range: 8.0-21.3). The most frequent reason for tooth loss was recurrence of periodontal disease. Tooth survival curves showed a statistically significant difference between smokers and non-smokers (p = 0.028). Mean CAL changed from 8.43 ± 1.86 (T0) to 6.47 ± 1.70 (T1) (p<0.001) and to 5.91 ± 1.83 (T2) (p<0.001). At T1, a CAL gain of ≥3 mm was measured in 35% of the defects while at T2 it was detected in 51% of cases.

CONCLUSIONS

Within their limitations, the present results have shown that in intrabony defects, the clinical improvements obtained following regenerative surgery with EMD can be maintained on a mean period of 10 years. Smoking status and maxillary molars were correlated with an increased risk for tooth and CAL loss, respectively. This article is protected by copyright. All rights reserved.

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

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

The adjunctive use of host modulators in non-surgical periodontal therapy. A systematic review of randomized, placebo-controlled clinical studies

BACKGROUND

Considering the role of the inflammatory host response in the pathogenesis of periodontitis, different host modulators have been proposed to enhance the outcomes of non-surgical periodontal therapy (NSPT), but their efficacy has not been fully clarified.

OBJECTIVES

This systematic review investigated the efficacy of host modulators combined with NSPT in reducing probing pocket depth (PPD) in periodontitis patients.

MATERIALS AND METHODS

Placebo-controlled RCTs with ≥6 months follow-up were searched. Meta-analysis was conducted when ≥5 studies using the same host modulator were identified.

RESULTS

Fifty eight studies met the inclusion criteria. After 6 months, local administration of 1.2% statin gels as adjuncts to NSPT significantly improved PPD reduction (1.83 mm) in infrabony defects and systemic administration of sub-antimicrobial dose doxycycline (SDD) in addition to NSPT improved PPD reduction of deep pockets. Administration of probiotics conferred limited clinical benefits. Local bisphosphonate and metformin gels showed potential for clinical use in infrabony defects, which needs to be confirmed.

CONCLUSIONS

Local delivery of statins in infrabony defects and systemic SDD for deep pockets may confer additional clinical benefits to NSPT. Their long-term effectiveness and safety need to be confirmed in independent multi-centred studies. Further studies are needed to confirm the benefit of other host modulators.

Critical features of periodontal flaps with regard to blood clot stability: A review

BACKGROUND

Wound healing is a multifactorial procedure involving different cell types and biological mediators. The principles of wound healing are also applicable to periodontal tissues. The formation and stability of blood clots play a vital role in successful healing of wounds in periodontal tissues. The aim of the present review was to highlight the vital factors of periodontal flaps associated with blood clot stability.

HIGHLIGHT

The data on periodontal regeneration and wound healing have evolved greatly in light of several factors, including space for blood clots and blood clot stabilization. In periodontal osseous defects, the stability of blood clots seems critical to wound healing. If mechanical forces can be managed by wound stabilization, the gingival flap-tooth root interface may show connective tissue repair. However, compromised adhesion is susceptible to mechanical forces and can cause wound breakage and epithelialization.

CONCLUSION

The presence of a thick blood clot may hinder the plasmatic circulation between the recipient bed and graft during the initial stage of healing, which is critical in cases of mucogingival surgery. Root conditioning can also determine the healing consequence by enhancing blood clot adhesion.

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

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

Does enamel matrix derivative application provide additional clinical benefits in the treatment of maxillary Miller class I and II gingival recession? A systematic review and meta-analysis

OBJECTIVE

This review aimed to evaluate the effects of enamel matrix derivative (EMD) in association with coronally advanced flap (CAF) or CAF + connective tissue graft (CTG) when compared with CAF alone or CAF + CTG for the treatment of gingival recessions (GR) in maxillary teeth.

METHODS

Five databases and gray literature were searched up to April 2020, to find randomized clinical trials comparing the clinical effects of CAF + EMD versus CAF alone (first group) or CAF + CTG + EMD versus CAF + CTG (second group) in the treatment of Miller class I and II or Cairo type I gingival recessions (GR). Random effects model of mean differences was used to determine the GR reduction, gain in keratinized tissue width (KTW), and gain in clinical attachment level (CAL). The trial sequential analysis (TSA) was implemented to determine the optimal information size (OIS) and imprecision using the GRADE approach. Bayes factors were calculated as complementary statistical evidence of p value.

RESULTS

From 1349 titles identified, 9 trials representing 336 GR were included. The meta-analysis showed a statistically significant difference for GR reduction and CAL gain in favor CAF + EMD (p ≤ 0.05). The additional effect of EMD showed a statistically significant difference in GR reduction in favor CAF + CTG + EMD (p ≤ 0.05). The differences in KTW gain proved to be not statistically significant in both comparison groups. The OIS were not met among meta-analyses. Evidence certainty according the GRADE approach proved to be moderate for GR reduction and gain in CAL, but very low for gain in KTW.

CONCLUSION

The adjunctive application of EMD in the treatment of GR in maxillary teeth either with CAF or CTG provided moderate certainty evidence in favor of their use for reduction in GR and gain in CAL at 6 and 12 months. However, their effect on the increase in keratinized tissue band height showed very low evidence certainty for its use.

CLINICAL RELEVANCE

To know if EMD could improve the results for root coverage.

Clinical effectiveness of anorganic bovine-derived hydroxyapatite matrix/cell-binding peptide grafts for regeneration of periodontal defects: a systematic review and meta-analysis

Aim: To ascertain clinical effectiveness of anorganic bovine-derived hydroxyapatite matrix/cell-binding peptide (ABM/P-15) for regeneration of periodontal defects. Materials & methods: Electronic databases (National Library of Medicine [Medline by PubMed], Cochrane Library [Wiley], CINAHL [EBSCO] and Medline [EBSCO]) were systematically searched up to December 2019. Randomized controlled clinical trials comparing ABM/P-15 grafts to conventional surgery for intrabony and gingival recession defects were included and evaluated intrabony defects including clinical attachment level (CAL), probing depth and gingival recession. Results: A significant gain in CAL (1.37 mm), and reduction in probing depth (1.22 mm) were shown by ABM/P-15 grafts than open flap debridement (p < 0.00001). The subgroup analysis also showed better results for ABM/P-15 grafts in CAL gain for intrabony defects. For furcation and gingival recession defects, no significant difference was seen. Conclusion: The adjunct use of ABM/P-15 grafts in conventional periodontal surgery is useful for periodontal regeneration of intrabony defects.

Clinical, radiographic, and patient-centered outcomes after use of enamel matrix proteins for the treatment of intrabony defects in patients with aggressive periodontitis: A 12-month multicenter clinical trial

BACKGROUND

The aim of this study was to evaluate the clinical, radiographic and patient-centered results of enamel matrix derivative (EMD) therapy in intrabony defects in aggressive periodontitis (AgP) patients and compare them with those in chronic periodontitis (CP) patients.

METHODS

Sixty intrabony defects in AgP and CP patients associated with ≥ 6 mm residual probing pocket depth (PPD) were included and randomly assigned to one of three groups: AgP+CS (conservative surgery) (n = 20); AgP+CS/EMD (n = 20); CP+CS/EMD (n  =  20). Clinical parameters were measured at baseline and after 6 and 12 months. Defect resolution (DR) and bone filling (BF) were used for radiographic analysis. The quality of life was recorded at baseline and 6 months using OHIP-14 and VAS scale in the early post-therapy period.

RESULTS

PPD and relative clinical attachment level (rCAL) improved for all groups during follow-up (P ≤ 0.05), and AgP+CS/EMD presented a higher rCAL gain (2.4 ± 1.0 mm) when compared to AgP control patients (1.6 ± 1.6 mm, P ≤ 0.05) after 12 months. No difference was observed between AgP+CS/EMD and CP+CS/EMD groups (P > 0.05). No radiographic differences were observed among groups at any time point (P > 0.05). All the groups reported a positive impact on OHIP-14 total score, without differences among them.

CONCLUSIONS

EMD therapy of intrabony defects promotes additional benefits in AgP patients, presenting a similar regeneration rate compared to CP patients, and has proven to be a viable therapy for the treatment of individuals with AgP.

The use of enamel matrix derivative in the treatment of class II furcation defects: systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of enamel matrix derivative (EMD) in the regeneration of class II furcation defects, used alone or in conjunction with biomaterials.

METHODS

Electronic database searches and hand searches were carried out and double-blind randomized controlled trials evaluating the use of EMD in class II furcation therapy were included, and a meta-analysis comparing the effect of open flap debridement (OFD) + βTCP/HA with and without EMD was carried out.

RESULTS

The initial search resulted in a total of 298 articles, after removing the duplicates and exclusions after analysing the titles, abstracts and full text, five studies were included for the qualitative synthesis and two for the quantitative analysis. The meta-analysis showed no statistical difference when comparing OFD + βTCP/ HA with or without EMD in the treatment of furcation defects in any of the evaluated parameters. According to GRADE, the certainty of the evidence for the variables evaluated was moderate.

CONCLUSION

The therapeutic modalities studied improved the periodontal clinical parameters of class II furcations, but the use of EMD in the treatment of these defects did not contribute to a clinical improvement that justified its use associated with the therapies/biomaterials. It is important to emphasize the need for more studies with larger samples to increase the certainty of the evidence reported in this review.

Effect of Flap Design for Enamel Matrix Derivative Application in Intraosseous Defects

Objective:

To systematically review the literature addressing the focused question: What is the effectiveness of different surgical and nonsurgical procedures combined with enamel matrix derivative (EMD) on clinical, radiographic, and patient-centered outcomes in intraosseous defects?

Methods:

Electronic (Medline, Scopus, and Cochrane databases) and hand literature searches were performed for studies including at least 1 treatment arm where EMD had been applied according to 1 of the following procedures: modified Widman flap; papilla preservation variants (PPVs), including papilla preservation technique, modified papilla preservation technique, and simplified papilla preservation technique; minimally invasive variants, including minimally invasive surgical approach and minimally invasive surgical technique; single-flap variants (SFVs), including single-flap approach and modified minimally invasive surgical technique; or nonsurgical application (flapless approach). Data from 42 selected articles were used to perform a network meta-analysis, and a hierarchy of surgical and nonsurgical applications of EMD was built separately for EMD and EMD + graft based on 6- to 12-mo clinical and radiographic outcomes.

Results:

Among surgical approaches, EMD was associated with best regenerative outcomes when applied through SFVs, with a mean clinical attachment level gain of 3.93 mm and a reduction in the intrabony component of the defect of 3.35 mm. For EMD + graft, limited differences in regenerative outcomes were observed among surgical procedures. PPVs were associated with the highest residual probing depth for EMD (4.08 mm) and EMD + graft (4.32 mm).

Conclusions:

In the treatment of periodontal intraosseous defects, 1) SFVs appear to optimize the regenerative outcomes of EMD; 2) substantial regenerative outcomes can be obtained with SFVs and conservative double flaps (i.e., PPVs and minimally invasive variants) when EMD is combined with a graft; and 3) residual probing depth was higher following PPVs for EMD and EMD + graft.

Knowledge Transfer Statement:

The results of the present systematic review and meta-analysis can be used by clinicians to identify the most effective surgical or nonsurgical procedure to treat an intraosseous defect with EMD or EMD + graft. The main findings indicate that when EMD application is indicated, surgical access based on a single flap seems the most appropriate to optimize clinical outcomes. The application of EMD + graft can be effectively combined with single flaps and conservative double flaps.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION(S)

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

Periodontal regeneration: a bibliometric analysis of the most influential studies

Aim: The aim of the present study is to identify the most influential research articles and their main characteristics in the specialty of periodontal regeneration. Materials & methods: The Web of Science database advance search was performed in the subject category of 'Dentistry, Oral surgery and medicine' from January 2004 to October 2018 to retrieve citations data. Results: The majority of the articles were published in journals dedicated to the specialty of periodontology. Among the top-cited articles most emphasized study types were randomized control trials (n = 25) and reviews (n = 20). Conclusion: The present bibliometric analysis provides comprehensive information regarding the contributions made in the advancement of regenerative periodontal research. The authors from developed countries and affiliated with interdisciplinary/multicenter institutions have predominantly contributed.

Experimental and clinical studies on regenerative periodontal therapy

The recognition of a periodontal therapy as a regenerative procedure requires the demonstration of new cementum, periodontal ligament, and bone coronal to the base of the defect. A diversity of regenerative strategies has been evaluated, including root surface conditioning, bone grafts and bone substitute materials, guided tissue regeneration, enamel matrix proteins, growth/differentiation factors, combined therapies and, more recently, tissue-engineering approaches. The aim of this chapter of Periodontology 2000 is to review the research carried out in Latin America in the field of periodontal regeneration, focusing mainly on studies using preclinical models (animal models) and randomized controlled clinical trials. This review may help clinicians and researchers to evaluate the current status of the therapies available and to discuss the challenges that must be faced in order to achieve predictable periodontal regeneration in clinical practice.

Expression of gingival crevicular fluid markers during early and late healing of intrabony defects after surgical treatment: a systematic review

BACKGROUND

Surgical treatments such as guided tissue regeneration (GTR) and access flap surgery are widely employed for the treatment of intrabony defects. However, little is known regarding the postoperative expression of gingival crevicular fluid (GCF) markers.

OBJECTIVE

The aim of this systematic review was to compare the expression of GCF markers following treatment of periodontal intrabony defects with guided tissue regeneration or access surgery. The association of the markers' expression with the clinical outcome was also assessed.

METHODS

An electronic literature search was conducted in MEDLINE, EMBASE, OpenGrey, LILACS and Cochrane Library up to December 2018 complemented by a manual search. Human, prospective clinical studies were identified. The changes from baseline up to 30 days (early healing) and 3 months (late healing) were assessed.

RESULTS

A total of 164 publications were identified and reviewed for eligibility. Of these, 10 publications fulfilled the inclusion criteria. The included studies evaluated 15 different GCF markers with a follow-up time between 21 and 360 days postoperatively. PDGF, VEGF and TIMP-1 changes were often investigated in the included studies; however, contrasting results were reported. Two studies agreed that both GTR and OFD lead to similar OPG level changes. TGF-β1 is increased early postoperatively, irrespective of the surgical technique employed.

CONCLUSION

There is limited evidence available on the expression of GCF markers after surgical interventions of intrabony periodontal defects. However, OPG and TGF-β1 tend to increase early post-operatively, irrespective of the surgical technique employed, irrespective of the surgical technique employed.

CLINICAL RELEVANCE

More well-designed, powered studies with sampling periods reflecting the regenerative process are needed, and future research should focus on employing standardised protocols for collecting, storing and analysing GCF markers.

New Perspectives in the Use of Biomaterials for Periodontal Regeneration

Periodontitis is a disease with a high prevalence among adults. If not treated, it can lead to loss of teeth. Periodontal therapy aims at maintaining patient’s teeth through infection control and correction of non-maintainable anatomies including—when possible—regeneration of lost periodontal tissues. The biological regenerative potential of the periodontium is high, and several biomaterials can be utilized to improve the outcome of periodontal therapy. Use of different natural and synthetic materials in the periodontal field has been studied for many years. The main materials used today in periodontology analyzed in this review are: Resorbable and non-resorbable barrier membranes; autogenous, allogeneic, xenogeneic, and alloplastic bone substitutes; biological agents, such as amelogenins; platelet-derived growth factor; bone morphogenic proteins; rh fibroblast growth factor 2; teriparatide hormone; platelet concentrates; and 3D scaffolds. With the development of new surgical techniques some concepts on periodontal regeneration that were strictly applied in the past seem to be not so critical today. This can have an impact on the materials that are needed when attempting to regenerate lost periodontal structures. This review aims at presenting a rationale behind the use of biomaterials in modern periodontal regeneration

Regeneration of the Periodontal Apparatus in Aggressive Periodontitis Patients

The purpose of this study is to evaluate and compare, retrospectively, the outcome of two different periodontal regeneration procedures in patients suffering from aggressive periodontitis (AgP). Twenty-eight patients were diagnosed with AgP, suffering from several intra-bony defects (IBD); that were treated by one of two periodontal regeneration techniques randomly assigned to each patient: a. guided tissue regeneration (GTR) or b. an application of extracted enamel matrix derivatives (EMD) combined with demineralized bone xenograft particles (DBX). Probing pocket depth (PPD), clinical attachment level (CAL), and gingival recession were recorded. Pre-treatment and follow-up (up to 10 years from the surgery) recordings were analyzed statistically within and between groups. A significant reduction was shown at time on PPD and CAL values, however, not between subject groups. CAL values decreased in all sites. At the EMD group (44 sites), CAL gain was 1.92 mm (±1.68) from pre-treatment to follow-up (p < 0.001) and at the GTR group (12 sites) CAL gain of 2.27 (±1.82) mm. In conclusion, 1⁻10 years observations have shown that surgical treatment of AgP patients by either GTR or by application of EMD/DBX results in similar successful clinical results.

Enamel biomimetics-fiction or future of dentistry

Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering, (i) enamel synthesis using physico-chemical means, (ii) protein matrix-guided enamel crystal growth, (iii) enamel surface remineralization, (iv) cell-based enamel engineering, and (v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as pH, heat and pressure have resulted in the formation of enamel-like crystal assemblies. Biochemical methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogenin-derived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. Going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues.

Enamel biomimetics-fiction or future of dentistry

Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering, (i) enamel synthesis using physico-chemical means, (ii) protein matrix-guided enamel crystal growth, (iii) enamel surface remineralization, (iv) cell-based enamel engineering, and (v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as pH, heat and pressure have resulted in the formation of enamel-like crystal assemblies. Biochemical methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogenin-derived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. Going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues.

Five pathways for tooth enamel engineering hold great promise for developing new technologies, leading to novel biomaterials and biotechnologies to regenerate enamel tissue. Tooth enamel is a unique tissue-specific biomaterial with exceptional structural and mechanical properties. In recent years, many approaches have been adopted to generate or regenerate this complex tissue; Mirali Pandya and Thomas Diekwisch of Texas A&M College of Dentistry, USA conducted a review of the current state and future directions of enamel tissue engineering. In their review, the authors focused on five pathways for enamel tissue engineering: (1) physical synthesis of enamel; (2) biochemical enamel engineering; (3) in situ enamel engineering; (4) cell-based enamel engineering; and (5) whole tooth regeneration. The authors conclude that those five approaches will help identify the biological mechanisms that lead to the generation of tooth enamel.