A randomized clinical multicentre trial comparing enamel matrix derivative and membrane treatment of buccal class II furcation involvement in mandibular molars. Part III: patient factors and treatment outcome

Collagen Scaffolds Laden with Human Periodontal Ligament Fibroblasts Promote Periodontal Regeneration in SD Rat Model

Periodontitis, a chronic inflammatory disease caused by microbial communities carrying pathogens, leads to the loss of tooth-supporting tissues and is a significant contributor to tooth loss. This study aims to develop a novel injectable cell-laden hydrogel consisted of collagen (COL), riboflavin, and a dental light-emitting diode (LED) photo-cross-linking process for periodontal regeneration. Utilizing α-SMA and ALP immunofluorescence markers, we confirmed the differentiation of human periodontal ligament fibroblasts (HPLFs) into myofibroblasts and preosteoblasts within collagen scaffolds in vitro. Twenty-four rats with three-wall artificial periodontal defects were divided into four groups, Blank, COL_LED, COL_HPLF, and COL_HPLF_LED, and histomorphometrically assessed after 6 weeks. Notably, the COL_HPLF_LED group showed less relative epithelial downgrowth (p < 0.01 for Blank, p < 0.05 for COL_LED and COL_HPLF), and the relative residual bone defect was significantly reduced in the COL_HPLF_LED group compared to the Blank and the COL_LED group (p < 0.05). The results indicated that LED photo-cross-linking collagen scaffolds possess sufficient strength to withstand the forces of surgical process and biting, providing support for HPLF cells embedded within them. The secretion of cells is suggested to promote the repair of adjacent tissues, including well-oriented periodontal ligament and alveolar bone regeneration. The approach developed in this study demonstrates clinical feasibility and holds promise for achieving both functional and structural regeneration of periodontal defects.

Tooth preservation vs. extraction and implant placement in periodontally compromised patients: A systematic review and analysis of studies

PURPOSE

The aim of this systematic review was to identify studies with a minimum of 5-years follow-up, reporting on the management of periodontally compromised teeth with either extraction and subsequent implant placement or teeth preservation with conventional periodontal treatment and application of regenerative procedures. The outcomes of these two approaches, based on clinical and radiographic data and the incidence of tooth- and implant-loss, were also investigated.

MATERIAL AND METHODS

A systematic search for studies reporting on clinical and radiographic outcomes of periodontal treatment or replacement of periodontally compromised teeth with implants was conducted in 3 electronic databases, followed by a hand-search in 8 journals. Only randomized controlled trials (RCTs), cohort studies, and case series with prospective design were included.

RESULTS

The initial search resulted in 1080 papers. After the first two screenings, 24 publications were selected for inclusion in this systematic review. The treatment protocols for the teeth preservation group contained nonsurgical and/or surgical periodontal treatment with or without regeneration procedures. The implant studies included extraction of periodontally involved teeth and implant placement with or without bone and soft tissue augmentation, followed by restoration with fixed dental prostheses (FDPs). Survival rates ranged between 81.8% and 100% in the tooth retention group, and between 94.8% and 100% in the implant group. In the extraction group, no complications were reported for 76.09% of the implants. Similarly, no complications were reported for 86.83% of the tooth retention group. The lack of standardized comparable studies prohibited conduction of a metaanalysis.

CONCLUSION

Both treatment approaches, treatment of periodontally compromised teeth, or tooth extraction followed by implant placement, present high survival rates. The application of bone regeneration techniques improves the long-term prognosis of periodontally involved teeth. Hence, treatment of periodontally involved teeth with subsequent application of a rigorous maintenance protocol can be a viable alternative for a number of years, before proceeding to extraction and replacement with dental implants. More well-designed randomized controlled trials are needed in order to draw definite conclusions on the subject.

Analysis of geometrical tomographic parameters of furcation lesions in periodontitis patients

Objectives

This study was aimed to investigate the relationship between geometric parameters of furcation lesions - maximum area of lesion opening (MALO), angle formed between the roots (ABR), lesion volume (LV) and presence and height of infra-osseous defects (IOD) - and the success of therapy with enamel matrix derivative proteins (EMD) in patients with grade C periodontitis, using cone-beam computed tomography (CBCT).

Methods

The study consisted of two groups of patients with grade C periodontitis: control (surgery) (n = 17) and test (surgery + EMD) (n = 17). Images parameters on CBCT were recorded using OnDemand3D and ITK-SNAP software.

Results

Pearson's correlation coefficient demonstrated that only IOD was statistically significant in the probing depth PD (P = 0.01), with a moderate positive correlation (R = 0.59). MALO was found to be statistically significant (P = 0.03) in the test group (surgery + EMD), with moderate negative correlation (R = -0.5).

Conclusion

The presence of infra-osseous defects and height were relevant in relation to the success of the type of treatment addressed in this study.

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.

Use of Platelet-Rich Fibrin in the Treatment of Grade 2 Furcation Defects: Systematic Review and Meta-Analysis

In periodontitis patients, furcation defects are crucial sites to regenerate due to their complex anatomy. Various modern surgical techniques and use of biomaterials have been suggested in the literature. Among all, platelet-rich fibrin (PRF) has potential in tissue regeneration thanks to its role in the release of growth factors. Therefore, the purpose of this study was to evaluate the beneficial effect of the addition of PRF to open flap debridement (OFD) or as an adjuvant to other biomaterials such as bone grafts in the treatment of grade 2 mandibular furcation defects. Systematic research was carried out on the databases Medline, Scopus, Embase, and Cochrane Library and registered on PROSPERO (CRD42020167662). According to the PICO guidelines by Cochrane, randomized trials and prospective non-randomized trials were evaluated, with a minimum follow-up period of 6 months. The inclusion criteria were the absence of systemic diseases, non-smoking patients, and a population aged from 18 to 65 years. Vertical pocket probing depth (PPD), vertical clinical attachment level (VCAL), and gingival recession (REC) were the primary outcomes. Vertical furcation depth (VFD), and the percentage of bone defect fill (%v-BDF) were considered as secondary outcomes. A meta-analysis of the primary and secondary outcomes was performed. Publication bias was assessed through a funnel plot. Eighty-four articles were initially extracted. Eight randomized clinical trials were analyzed according to the exclusion and inclusion criteria. The Quality assessment instrument (QAI) revealed four articles at low risk of bias, one at moderate, and three at high risk of bias. The metanalysis showed significant data regarding PPD, VCAL, VFD and %v-BDF in the comparison between PRF + OFD vs. OFD alone. The adjunct of PRF to a bone graft showed a significant difference for VCAL and a not statistically significant result for the other involved parameters. In conclusion, the adjunctive use of PRF to OFD seems to enhance the periodontal regeneration in the treatment of grade 2 furcation defects. The combination of PRF and bone graft did not show better clinical results, except for VCAL, although the amount of literature with low risk of bias is scarce. Further well-designed studies to evaluate the combination of these two materials are therefore needed.

Evaluation of Different Autologous Platelet Concentrate Biomaterials: Morphological and Biological Comparisons and Considerations

The field of regeneration interventions in oral and maxillofacial surgeries still represents a challenge for researchers and clinicians. Understanding the biological and morphological behaviour of human cells towards the materials used for the regeneration surgeries is key to successfully choosing and applying the appropriate biomaterials for specific clinical situations. The aim of the study was the biological and morphological evaluation of autologous platelet concentrate materials obtained with different protocols, in culture with human periodontal ligament fibroblasts (HPLF). The study design included the evaluation of Leukocyte-Platelet-Rich-Fibrin (L-PRF), Concentrated Growth Factors (CGF) and autologous platelet gel (APG) in contact with the HPLF cell line after 24 h, 72 h and 7 days of in vitro culture. Cell proliferation and, therefore, viability were evaluated with XTT assays. The morphological response of the cells was evaluated by light microscopy, scanning electron microscopy and confocal microscopy. The XTT assay showed an interesting response in the growth curve. In particular, the material that gave the best results was the CGF. The morphological data supported the XTT assay, showing the best results for the CGF and L-PRF. In conclusion, all the platelet-derived materials stimulated the onset of the growth of the HPLF cell line, making them promising options for periodontal regeneration interventions.

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.

Early wound healing outcomes after regenerative periodontal surgery with enamel matrix derivatives or guided tissue regeneration: a systematic review

BACKGROUND

Proper wound healing after regenerative surgical procedures is an essential issue for clinical success. Guided tissue regeneration (GTR) and application of enamel matrix derivatives (EMD) are common means to regenerate periodontal tissues. Both methods bear considerable advantages due to their special characteristics, but also go along with certain disadvantages. Today, there is no consensus in the literature whether GTR or EMD show better results regarding early wound healing, which is considered a crucial stage in periodontal regeneration. Therefore, the aim of the present systematic review was to compare the early wound healing after regenerative periodontal surgery with either EMD or GTR treatment.

METHODS

An electronic literature search in PubMed was performed to identify randomized clinical trials (RCTs) or clinical trials (CTs) comparing regenerative surgery employing EMD and/or GTR in patients with chronic periodontitis. Among the finally included studies, a qualitative and quantitative data extraction regarding early wound healing parameters was performed. Primary outcome parameters were early wound healing index (EWH), flap dehiscence, membrane exposure, suppuration and abscess formation during the first 6 weeks. As secondary parameters, swelling and allergic reactions were assessed.

RESULTS

Seven studies reporting 220 intrabony periodontal defects in 199 patients were analysed. Flap dehiscence was observed in two studies in 12% of the GTR treated sites and in 10.3% of those treated with EMD. Membrane exposure was evaluated in five studies and was registered in the 28.8% of the defects, while no dehiscence was reported on the EMD group. Swelling was reported only in one study in 8/16 GTR sites and 7/16 EMD sites. Due to considerable heterogeneity of parameters no meta-analysis was possible.

CONCLUSIONS

Due to considerable heterogeneity of the published studies a clear beneficial effect of the EMD on the early wound healing outcomes after surgical treatment of periodontal intrabony defects cannot be confirmed. Standardized RCT studies are needed in order to allow for proper comparison of early wound healing after both types of surgical approaches.

One percent alendronate and aloe vera gel local host modulating agents in chronic periodontitis patients with class II furcation defects: A randomized, controlled clinical trial

AIM

Alendronate (ALN) has antiresorptive and osteostimulative properties. The major component of aloe vera (AV) gel is acemannan, which has been found to have osteogenic properties. The aim of the present study is to explore the effectiveness of 1% ALN and AV gel as an adjunct to scaling and root planing (SRP) in chronic periodontitis patients with class II furcation defects.

METHODS

Ninety volunteers were randomly assigned to three treatment groups: (a) SRP plus placebo gel; (b) SRP plus 1% ALN gel; and (c) SRP plus AV gel. Clinical and radiographic parameters were recorded at baseline and at 6 and 12 months.

RESULTS

The mean probing depth reduction and relative horizontal clinical attachment level (CAL) and relative vertical CAL gains were greater in the ALN group than in the AV and placebo groups at 6 and 12 months. Furthermore, a significantly greater mean percentage of defect depth reduction (DDR) was found in the ALN group (38.09 ± 9.53, 44.86 ± 6.29) than the AV groups (11.94 ± 15.10, 14.59 ± 25.49) at 6 and 12 months, respectively.

CONCLUSION

ALN showed significant improvement in all clinical parameters, along with greater DDR, compared to AV in the treatment of class II furcation defects as an adjunct to SRP.

A clinicoradiographic assessment of 1% metformin gel with platelet-rich fibrin in the treatment of mandibular grade II furcation defects

Background:

Management of furcation defects is challenging, and constantly newer therapeutic strategies are evolving. Platelet-rich fibrin (PRF) is successfully used alone and in combination with various agents in the furcation defects. Lately, metformin (MF), a second generation biguanide has gained popularity owing to its osteogenic potential.

Aims and Objectives:

The aim of the present study was to evaluate the clinical and radiographic effectiveness of open flap debridement (OFD) and PRF when compared to OFD + PRF + 1% MF gel in the management of mandibular Grade II furcation defects.

Materials and Methods:

Thirty mandibular grade II furcation defects were stratified into two groups; in one group OFD and PRF is used, and the other group had an additional MF gel with PRF in OFD. Clinical parameters such as plaque index, modified sulcus bleeding index, probing pocket depth (PD), relative vertical attachment level (RVAL), and relative horizontal attachment level (RHAL) were recorded at baseline and at 6 months. Radiovisiography and ImageJ software were used to evaluate the intrabony defect depth.

Results:

The OFD + PRF + MF group showed significantly higher probing PD reduction, RVAL and RHAL gain than the OFD + PRF group.

Conclusions:

PRF when combined with a potential osteogenic agent like MF can provide a better therapeutic benefit to a furcation involved tooth.

In vivo periodontal tissue regeneration by periodontal ligament stem cells and endothelial cells in three-dimensional cell sheet constructs

BACKGROUND AND OBJECTIVE

Chronic periodontitis causes damage to tooth-supporting tissues, resulting in tooth loss in adults. Recently, cell-sheet-based approaches have been studied to overcome the limitations of conventional cytotherapeutic procedures for periodontal regeneration. The purpose of the present study was to investigate the regenerative potential of periodontal ligament stem cells (PDLSCs) and human umbilical vein endothelial cells (HUVECs) in three-dimensional (3D) cell sheet constructs for periodontal regeneration in vivo.

MATERIAL AND METHODS

PDLSCs, HUVECs or co-cultures of both cells were seeded onto temperature-responsive culture dishes, and intact cell sheets were fabricated. Cell sheets were wrapped around the prepared human roots in three different combinations and implanted subcutaneously into immunodeficient mice.

RESULTS

Histological evaluation revealed that after 2, 4 and 8 wk of implantation, periodontal ligament-like tissue arrangements were observed around the implanted roots in experimental groups compared with controls. Vascular lumens were also observed in periodontal compartments of HUVEC-containing groups. Periodontal ligament regeneration, cementogenesis and osteogenesis were evident in the experimental groups at both weeks 4 and 8, as shown by immunostaining for periostin and bone sialoprotein. Human cells in the transplanted cell sheets were stained by immunohistochemistry for the presence of human mitochondria.

CONCLUSIONS

The 3D cell sheet-based approach may be potentially beneficial and is thus encouraged for future regenerative periodontal therapy.

Influence of Enamel Matrix Derivative on Human Epithelial Cells In Vitro

BACKGROUND

In periodontal therapy enamel matrix derivative (EMD) has been successfully used for tissue regeneration by altering activity of various cells involved in periodontal regeneration. Studies have focused primarily on clinical parameters and outcome. Effects of EMD on oral epithelial cells are of crucial importance in order to understand the biology of regeneration. Aims of this study are to investigate proliferative and cytotoxic effects of EMD on oral epithelial cells and their possible influences on epithelial barrier function.

METHODS

SCC-25 cells, a human squamous cell carcinoma cell line, and primary keratinocytes were either treated with EMD dissolved in culture medium or added to wells/inserts precoated with EMD. Cells were incubated for 24, 48, and 72 hours. Proliferation rate was analyzed measuring the 5-bromo-2'-deoxyuridine nucleotide uptake. Cytotoxic effects of EMD treatment were sampled by lactate dehydrogenase release. Alterations of the epithelial barrier function induced by EMD were investigated by analysis of transepithelial electrical resistance (TER).

RESULTS

Statistically significant inhibitory effects of both malignant and primary cell proliferation could be demonstrated by precoating culture plate wells with EMD. No cytotoxic effects caused by EMD were detected. Precoating of inserts with EMD induced a significant increase of TER and barrier function.

CONCLUSIONS

This investigation compares applying EMD in solution to cells with precoating of wells with EMD. When precoating of wells was used solely, inhibition of cell proliferation was evident. Precoating may represent more suitable clinical usage. Furthermore, prelayering EMD induced an increase of TER of primary cells. These results suggest EMD may enhance barrier function.

Twenty years of enamel matrix derivative: the past, the present and the future

BACGROUND

On June 5th, 2015 at Europerio 8, a group of leading experts were gathered to discuss what has now been 20 years of documented evidence supporting the clinical use of enamel matrix derivative (EMD). Original experiments led by Lars Hammarström demonstrated that enamel matrix proteins could serve as key regenerative proteins capable of promoting periodontal regeneration including new cementum, with functionally oriented inserting new periodontal ligament fibres, and new alveolar bone formation. This pioneering work and vision by Lars Hammarström has paved the way to an enormous amount of publications related to its biological basis and clinical use. Twenty years later, it is clear that all these studies have greatly contributed to our understanding of how biologics can act as mediators for periodontal regeneration and have provided additional clinical means to support tissue regeneration of the periodontium.

AIMS

This review article aims to: (1) provide the biological background necessary to understand the rational for the use of EMD for periodontal regeneration, (2) present animal and human histological evidence of periodontal regeneration following EMD application, (3) provide clinically relevant indications for the use of EMD and (4) discuss future avenues of research including key early findings leading to the development of Osteogain, a new carrier system for EMD specifically developed with better protein adsorption to bone grafting materials.

Mandibular Class II Furcation Defect Treatment: Effects of the Addition of Platelet Concentrates to Open Flap: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

BACKGROUND

To improve the efficacy and outcomes of regenerative therapy for furcation defects, the use of platelet concentrates (PCs) in addition to open flap debridement (OFD) has been investigated. The aim of this systematic review is to evaluate whether mandibular Class II furcation defects treated with the addition of PC to OFD heal with a significant improvement in the following: 1) horizontal clinical attachment level (HCAL); 2) vertical clinical attachment level (VCAL); 3) probing depth (PD); and 4) level of gingival margin (LGM).

METHODS

Electronic databases (MEDLINE, EBSCO Library, Cochrane Database of Systematic Reviews, and SCOPUS) were searched for randomized clinical trials to address the use of PCs in combination with OFD compared with a control group without PCs for the treatment of mandibular Class II furcation defects in humans and to provide data on the above reported outcome measures. The results of selected studies were converted to mean difference and standard error and interpolated using the inverse of variance test. Heterogeneity was investigated using both the Higgins index and the Q test.

RESULTS

Of 254 articles screened, only 11 were read in full text, and three of these were included in the meta-analysis. The addition of PCs to OFD revealed a small improvement in the following: 1) HCAL (mean difference, 1.36 mm; 95% confidence interval [CI] = 1.07 to 1.65); 2) VCAL (mean difference, 1.54 mm; 95% CI = 1.23 to 1.85); and 3) PD (mean difference, 1.83 mm; 95% CI = 1.36 to 2.29). No differences were found for the LGM. Heterogeneity across the studies was high, and all the three included studies were performed in one country.

CONCLUSIONS

Adding PCs to OFD for the treatment of mandibular Class II furcation defects may lead to slight improvements in clinical parameters. Nonetheless, because of the high heterogeneity of the very small number of reported studies and the small effect size, no definitive conclusion can be achieved about the clinical application of such a treatment option.

Periodontal regeneration - furcation defects: a systematic review from the AAP Regeneration Workshop

BACKGROUND

The aim of this review is to present the available evidence regarding the effectiveness of different regenerative approaches for the treatment of furcation defects in specific clinical scenarios compared with conventional surgical therapy to provide clinical guidelines for the therapeutic management of furcation defects and to identify priorities for future research that may advance the understanding of periodontal regenerative medicine.

METHODS

A comprehensive search based on predetermined eligibility criteria was conducted to identify human original studies and systematic reviews on the topic of periodontal regeneration of furcation defects. Two reviewers independently screened the title and abstract of the entries yielded from the initial search. Subsequently, both reviewers read the full-text version of potentially eligible studies, made a final article selection, and extracted the data of the selected studies considering specific clinical scenarios. The clinical scenarios contemplated in this review included the following: 1) facial and interproximal Class I defects in maxillary molars; 2) facial and lingual Class I defects in mandibular molars; 3) facial and interproximal Class II furcation defects in maxillary molars; 4) facial and lingual Class II furcation defects in mandibular molars; 5) Class III furcation defects in maxillary molars; 6) Class III furcation defects in mandibular molars; and 7) Class I, II, or III furcation defects in maxillary premolars. Endpoints of interest included different clinical, radiographic, microbiologic, histologic, and patient-reported outcomes.

RESULTS

The initial search yielded a total of 1,500 entries. The final selection consisted of 150 articles, of which six were systematic reviews, 109 were clinical trials, 27 were case series, and eight were case reports. A summary of the main findings of previously published systematic reviews and the available evidence relative to the indication of regenerative approaches for the treatment of furcation defects compared with conventional surgical therapy are presented. Given the marked methodologic heterogeneity and the wide variety of materials and techniques applied in the selected clinical trials, the conduction of a meta-analysis was not viable.

CONCLUSIONS

On the basis of the reviewed evidence, the following conclusions can be drawn. 1) Periodontal regeneration has been demonstrated histologically and clinically for the treatment of maxillary facial or interproximal and mandibular facial or lingual Class II furcation defects. 2) Although periodontal regeneration has been demonstrated histologically for the treatment of mandibular Class III defects, the evidence is limited to one case report. 3) Evidence supporting regenerative therapy in maxillary Class III furcation defects in maxillary molars is limited to clinical case reports. 4) In Class I furcation defects, regenerative therapy may be beneficial in certain clinical scenarios, although most Class I furcation defects may be successfully treated with non-regenerative therapy. 5) Future research efforts should be primarily directed toward the conduction of clinical trials to test novel regenerative approaches that place emphasis primarily on patient-reported outcomes and also on histologic demonstration of periodontal regeneration. Investigators should also focus on understanding the influence that local, systemic, and technical factors may have on the outcomes of regenerative therapy in furcation defects.

Estrogen enhances the bone regeneration potential of periodontal ligament stem cells derived from osteoporotic rats and seeded on nano-hydroxyapatite/collagen/poly(L-lactide)

This study investigated the effects of estrogen on the bone regeneration potential of periodontal ligament stem cells (PDLSCs) derived from osteoporotic rats and seeded on a collagen-based composite scaffold [nano-hydroxyapatite/collagen/poly(L-lactide) (nHAC/PLA)]. For this purpose, 48 healthy 3‑month-old Sprague-Dawley female rats were divided into 2 groups as follows: the bilaterally ovariectomized (OVX) rats and sham‑operated rats. The PDLSCs were isolated at 3 months after surgery (by which time postmenopausal osteoporosis had developed). The effects of estrogen on the characteristics of these cells seeded in a culture plate and of the cells seeded on nHAC/PLA were then investigated. The PDLSC + nHAC/PLA constructs were implanted subcutaneously into the backs of severe combined immunodeficient (SCID) mice for 12 weeks in order to examine the role of estrogen in the bone formation ability of PDLSCs derived from osteoporotic rats. The results from methyl thiazolyl tetrazolium (MTT) assay revealed that the proliferation of the cells derived from the rats in the OVX group was significantly higher than that of the cells derived from the rats in the sham-operated group at the stage of logarithmic growth. The staining intensity of alkaline phosphatase (ALP) and the mineralization of the cells derived from the rats in the OVX group was significantly weaker than that of the cells from the rats in the sham-operated group. When the PDLSCs were seeded on nHAC/PLA, ALP activity, osteocalcin (OCN) secretion, mineral formation and the mRNA expression levels of ALP, OCN, estrogen receptor (ER)α and ERβ in the cells derived from the rats in the OVX group were markedly decreased. Treatment with 17β-estradiol (E2) significantly weakened the proliferative ability of the cells derived from the OVX group rats, and enhanced their osteogenic differentiation ability and the mRNA expression levels of ALP, OCN, ERα and ERβ. When the constructs were implanted into the backs of SCID mice for 12 weeks, the results of histological analysis indicated that the constructs derived from the OVX group rats had a few newly formed bones and osteoids; however, a great number of newly formed bones and osteoids were present in the ones from the sham-operated group and the OVX + E2 group rats. Our findings further indicate that estrogen deficiency impairs the osteogenic differentiation potential of PDLSCs, and that ER plays an important role in the bone regeneration ability of PDLSCs. Estrogen enhances the bone regeneration potential of PDLSCs derived from osteoporotic rats and seeded on nHAC/PLA. This study may provide insight into the clinical management of periodontal bone tissue repair in postmenopausal women with the use of estrogen-mediated PDLSCs seeded on nHAC/PLA.

Diagnostic accuracy of cone beam computed tomography in identification and postoperative evaluation of furcation defects

Background:

Decision-making in periodontal therapeutics is critical and is influenced by accurate diagnosis of osseous defects, especially furcation involvement. Commonly used diagnostic methods such as clinical probing and conventional radiography have their own limitations. Hence, this study was planned to evaluate the dimensions of furcation defects clinically (pre- and post-surgery), intra-surgically, and by cone beam computed tomography (CBCT) (pre- and post-surgery).

Materials and Methods:

The study comprised a total of 200 Grade II furcation defects in forty patients, with a mean age of 38.05 ± 4.77 years diagnosed with chronic periodontitis which were evaluated clinically (pre- and post-surgically), by CBCT (pre- and post-surgically), and intrasurgically after flap reflection (40 defects in each). After the presurgical clinical and CBCT measurements, demineralized freeze-dried bone allograft was placed in the furcation defect and the flaps were sutured back. Six months later, these defects were evaluated by recording measurements clinically, i.e., postsurgery clinical measurements and also postsurgery CBCT measurements (40 defects each).

Results:

Presurgery clinical measurements (vertical 6.15 ± 1.71 mm and horizontal 3.05 ± 0.84 mm) and CBCT measurements (vertical 7.69 ± 1.67 mm and horizontal 4.62 ± 0.77 mm) underestimated intrasurgery measurements (vertical 8.025 ± 1.67 mm and horizontal 4.82 ± 0.67 mm) in both vertical and horizontal aspects, and the difference was statistically not significant (vertical P = 1.000, 95% confidence interval [CI], horizontal P = 0.867, 95% CI). Further, postsurgery clinical measurements (vertical 2.9 ± 0.74 mm and horizontal 1.52 ± 0.59 mm) underestimated CBCT measurements (vertical 3.67 ± 1.17 mm and horizontal 2.45 ± 0.48 mm). There was statistically significant difference between presurgery clinical–presurgery CBCT (P < 0.0001, 95% CI) versus postsurgery clinical–postsurgery CBCT (P < 0.0001, 95% CI) values in both vertical and horizontal aspects.

Conclusion:

The use of CBCT appears to be prudent for accurate diagnosis of furcation defects in advanced periodontal diseases. Presurgical and postsurgical three-dimensional imaging enable the clinician to optimize treatment decisions and assess the quantum of healing more definitively.

Induced Pluripotent Stem Cells and Periodontal Regeneration

Periodontitis is a chronic inflammatory disease which leads to destruction of both the soft and hard tissues of the periodontium. Tissue engineering is a therapeutic approach in regenerative medicine that aims to induce new functional tissue regeneration via the synergistic combination of cells, biomaterials, and/or growth factors. Advances in our understanding of the biology of stem cells, including embryonic stem cells and mesenchymal stem cells, have provided opportunities for periodontal tissue engineering. However, there remain a number of limitations affecting their therapeutic efficiency. Due to the considerable proliferation and differentiation capacities, recently described induced pluripotent stem cells (iPSCs) provide a new way for cell-based therapies for periodontal regeneration. This review outlines the latest status of periodontal tissue engineering and highlights the potential use of iPSCs in periodontal tissue regeneration.

Porphyromonas gingivalis lipopolysaccharides regulate functions of bone marrow mesenchymal stem cells

OBJECTIVES

Periodontitis is one of the most widespread inflammatory diseases; it causes tooth loss and is also associated with a variety of systemic diseases. Mesenchymal stem cells (MSCs) have been used to treat periodontitis. However, it is unknown whether bacterial toxins in the periodontal environment affect MSC-mediated periodontal regeneration. Porphyromonas gingivalis lipopolysaccharides (Pg-LPS) are key toxins for development of periodontitis. The purpose of the present study was to investigate effects of P. gingivalis LPS on biological properties of MSCs.

MATERIALS AND METHODS

Mesenchymal stem cells from bone marrow (BMMSCs) were treated with different concentrations of P. gingivalis LPS (0.1-10 μg/ml), then its effects were evaluated on biological properties of BMMSCs including proliferation, apoptosis, osteogenic differentiation and capacities to inhibit activated T cells.

RESULTS

Low concentration of P. gingivalis LPS (0.1 μg/ml) accelerated MSC proliferation, osteogenic differentiation and capacities to inhibit activated T cells via up-regulation of nitric oxide. However, high concentration of P. gingivalis LPS (10 μg/ml) reduced MSC proliferation, osteogenic differentiation and capacities to inhibit activated T cells.

CONCLUSIONS

Mesenchymal stem cells were functionally different following exposure to P. gingivalis LPS at the investigated concentrations. These findings suggest that MSC-mediated periodontal regeneration may be regulated by P. gingivalis LPS.

Platelet rich fibrin (Prf) and β-tricalcium phosphate with coronally advanced flap for the management of grade-II furcation defect

BACKGROUND

Multirooted teeth offer unique and challenging problems due to the furcation area, creates situations in which routine periodontal procedures are somewhat limited and special procedures are generally required.

CASE DETAIL

The present case was showing the management of grade II furcation defect by platelet rich fibrin (PRF) and β-Tricalcium phosphate with coronally advanced flap.

CONCLUSION

Platelet rich fibrin and β-Tricalcium phosphate with coronally advanced flap have been shown to be a promising and successful approach for the treatment of furcation defect. Its gaining clinical attachment significantly manages both the gingival recession and furcation involvement simultaneously.

A novel porcine collagen GTR membrane for treatment of Class II molar furcation involvement

Guided tissue regeneration (GTR) in the management of the periodontal furcation invasion is effective. Recent studies showed significant clinical improvement with different materials. The purpose of this study is to provide clinical evaluations of the bone repair potential of GTR combined with a novel porcine collagen membrane in the treatment of human molar Class II furcations. Fifty-one patients, 33 males and 18 females, with no systemic disease and a mean age of 49.1 years, participated in this study after phase I periodontal therapy. Probing depth, attachment loss and radiographic examination were recorded and analyzed before and after GTR therapy with collagen membrane. In the soft tissue measurement, the periodontal pocket (PD) depth was 5.283±0.283 mm before the surgery and improved to 2.631±0.147 mm at 9 months after surgery (p<0.05). Attachment loss also showed similar results. The attachment level was 5.547±0.3 mm before the surgery, and 2.911±0.188 mm at 9 months after surgery (p<0.05). According to the measurements the attachment gain was 2.636±0.168 mm after GTR surgery with porcine collagen membrane. According to this study, the porcine collagen membrane can perform with exceptional results in attachment level gain for the Class II periodontal furcation involvement.

Proteomic analysis of gingival tissue and alveolar bone during alveolar bone healing

Bone tissue regeneration is orchestrated by the surrounding supporting tissues and involves the build-up of osteogenic cells, which orchestrate remodeling/healing through the expression of numerous mediators and signaling molecules. Periodontal regeneration models have proven useful for studying the interaction and communication between alveolar bone and supporting soft tissue. We applied a quantitative proteomic approach to analyze and compare proteins with altered expression in gingival soft tissue and alveolar bone following tooth extraction. For target identification and validation, hard and soft tissue were extracted from mini-pigs at the indicated times after tooth extraction. From triplicate experiments, 56 proteins in soft tissue and 27 proteins in alveolar bone were found to be differentially expressed before and after tooth extraction. The expression of 21 of those proteins was altered in both soft tissue and bone. Comparison of the activated networks in soft tissue and alveolar bone highlighted their distinct responsibilities in bone and tissue healing. Moreover, we found that there is crosstalk between identified proteins in soft tissue and alveolar bone with respect to cellular assembly, organization, and communication. Among these proteins, we examined in detail the expression patterns and associated networks of ATP5B and fibronectin 1. ATP5B is involved in nucleic acid metabolism, small molecule biochemistry, and neurological disease, and fibronectin 1 is involved in cellular assembly, organization, and maintenance. Collectively, our findings indicate that bone regeneration is accompanied by a profound interaction among networks regulating cellular resources, and they provide novel insight into the molecular mechanisms involved in the healing of periodontal tissue after tooth extraction.

Comparative evaluation of autologous platelet-rich fibrin and platelet-rich plasma in the treatment of mandibular degree II furcation defects: a randomized controlled clinical trial

BACKGROUND

The treatment of molar furcation defects remains a considerable challenge in clinical practice. The identification of clinical measurements influential to treatment outcomes is critical to optimize the results of surgical periodontal therapy. The present study aimed to explore the clinical and radiographical effectiveness of autologous platelet-rich fibrin (PRF) and autologous platelet-rich plasma (PRP) in the treatment of mandibular degree II furcation defects in subjects with chronic periodontitis.

MATERIAL AND METHODS

Seventy-two mandibular degree II furcation defects were treated with either autologous PRF with open flap debridement (OFD; 24 defects) or autologous PRP with OFD (25), or OFD alone (23). Clinical and radiological parameters such as probing depth, relative vertical clinical attachment level and horizontal clinical attachment level along with gingival marginal level were recorded at baseline and 9 mo postoperatively.

RESULTS

All clinical and radiographic parameters showed statistically significant improvement at both the test sites (PRF with OFD and PRP with OFD) compared to those with OFD alone. Relative vertical clinical attachment level gain was also greater in PRF (2.87 ± 0.85 mm) and PRP (2.71 ± 1.04 mm) sites as compared to control site (1.37 ± 0.58 mm), and relative horizontal clinical attachment level gain was statistically significantly greater in both PRF and PRP than in the control group.

CONCLUSIONS

The use of autologous PRF or PRP were both effective in the treatment of furcation defects with uneventful healing of sites.

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

BACKGROUND

Enamel matrix derivative (EMD) is commonly used in periodontal therapy. The aim of this systematic review is to give an updated answer to the question of whether the additional use of EMD in periodontal therapy is more effective compared with a control or other regenerative procedures.

METHODS

A literature search in MEDLINE (PubMed) for the use of EMD in periodontal treatment was performed up to May 2010. The use of EMD in treatment of intrabony defects, furcations, and recessions was evaluated. Only randomized controlled trials with ≥1 year of follow-up were included. The primary outcome variable for intrabony defects was the change in clinical attachment level (CAL), for furcations the change in horizontal furcation depth, and for recession complete root coverage.

RESULTS

After screening, 27 studies (20 for intrabony defects, one for furcation, and six for recession) were eligible for the review. A meta-analysis was performed for intrabony defects and recession. The treatment of intrabony defects with EMD showed a significant additional gain in CAL of 1.30 mm compared with open-flap debridement, EDTA, or placebo, but no significant difference compared with resorbable membranes was shown. The use of EMD in combination with a coronally advanced flap compared with a coronally advanced flap alone showed significantly more complete root coverage (odds ratio of 3.5), but compared with a connective tissue graft, the result was not significantly different. The use of EMD in furcations (2.6 ± 1.8 mm) gave significantly more improvement in horizontal defect depth compared with resorbable membranes (1.9 ± 1.4 mm) as shown in one study.

CONCLUSIONS

In the treatment of intrabony defects, the use of EMD is superior to control treatments but as effective as resorbable membranes. The additional use of EMD with a coronally advanced flap for recession coverage will give superior results compared with a control but is as effective as a connective tissue graft. The use of EMD in furcations will give more reduction in horizontal furcation defect depth compared with resorbable membranes.

Bone regeneration using a synthetic matrix containing enamel matrix derivate

PURPOSE

The aim of the present study was to test whether the delivery of enamel matrix derivate (EMD) via synthetic polyethylene glycol (PEG)-based hydrogels with and without RGD sequences enhances bone formation in vivo.

MATERIAL AND METHODS

In each of 10 rabbits, four titanium cylinders were placed on the external cortical bones of their calvaria. The following four treatment modalities were randomly allocated: One of the four cylinders was left empty (control), the other three were filled with a combination of PEG matrix with hydroxyapatite/tricalciumphosphate (HA/TCP) granules and EMD in a concentration of 100 μg/ml (test 1) or 500 μg/ml (test 2) or 500 μg/ml and RGD peptide (test 3). After 8 weeks, the animals were sacrificed and ground sections were obtained for histological analysis. For statistical analysis, the Kruskal-Wallis test was applied (P<0.05).

RESULTS

The histomorphometric analysis revealed a statistically larger area fraction of newly formed bone in the EMD 500/RGD group (54.8±14.5%) compared with the control group (28.7±10.3%) and the EMD 500 group (31.2±14.1%) and non-significantly higher area fraction compared with the EMD 100 group (38.2±10.4%). The percentage of mineralized bone showed no statistically significant differences among the four groups. The mean percentage of mineralized bone was 13.6±3.3% in the control group, 14.2±5.8% in the EMD 100 group, 11.69±5.9% in the EMD 500 group and 15.66±5.2% in the EMD 500/RGD group. No statistically significant difference regarding the bone-to-graft contact between the EMD 100 group (23±15.7%), the EMD 500 group (22.2±14.6%) and the EMD 500/RGD group (21.6±8.8%) was observed.

CONCLUSIONS

The combination of a PEG matrix containing EMD with HA/TCP granules had no effect on the formation of mineralized bone tissue in rabbit calvaria. The addition of RGD peptide to the PEG/EMD 500 combination increased the area fraction of newly formed bone compared with the other treatment groups. Further studies are indicated to study a possible synergistic effect of EMD and RGD.

Porous titanium granules in the treatment of mandibular Class II furcation defects: a consecutive case series

BACKGROUND

The osteoconductive potential of titanium is interesting from the perspective of periodontal surgery and reconstitution of osseous defects. The aim of the present consecutive case series is to evaluate a surgical strategy based on the use of porous titanium granules (PTG) in the treatment of Class II buccal furcation defects in mandibular molars in humans.

METHODS

Surgical intervention with PTG used as a bone graft substitute was performed in 10 patients with 10 mandibular Class II buccal furcation defects. Clinical parameters (probing depth (PD), clinical attachment level (CAL), gingival recession (GR), gingival index (GI), bleeding on probing (BOP), and horizontal and vertical bone sounding) and radiographic measurements of vertical furcation height were compared among baseline (presurgery), 6, and 12 months (post-surgery). The significance level (α) was set at 0.05.

RESULTS

With respect to vertical and horizontal bone sounding measurements, CAL, and GR, no significant improvements between baseline and the 12-month examination were seen. Both PD and radiographic vertical furcation height were significantly reduced between baseline and 12 months. When comparing the baseline to 12-month data, a significantly lower GI score was seen but the BOP score was unchanged. None of the treated teeth showed radiographic signs of root resorption.

CONCLUSION

This study suggests that PTG is safe to use in close proximity to root surfaces, but no significant improvements in clinical endpoints of defect resolution were observed.

Autologous platelet-rich fibrin in the treatment of mandibular degree II furcation defects: a randomized clinical trial

BACKGROUND

Platelet-rich fibrin (PRF), an intimate assembly of cytokines, glycan chains, and structural glycoproteins enmeshed within a slowly polymerized fibrin network, has the potential to accelerate soft and hard tissue healing. This double-masked randomized study is designed to evaluate the effectiveness of autologous PRF in the treatment of mandibular degree II furcation defects compared with open flap debridement (OFD).

METHODS

Using a split-mouth design, 18 patients with 36 mandibular degree II furcation defects were randomly allotted and treated either with autologous PRF and OFD or OFD. Plaque index, sulcus bleeding index, probing depth, relative vertical and horizontal clinical attachment level, gingival marginal level, and radiographic bone defect were recorded at baseline and 9 months postoperatively. Comparison between indices between the test and control groups was performed using the paired t test except for plaque index and sulcus bleeding index data, which used the χ(2) test.

RESULTS

All clinical and radiographic parameters showed statistically significant improvement at the sites treated with PRF and OFD compared to those with OFD alone.

CONCLUSION

Within the limitation of this study, significant improvement with autologous PRF implies its role as a regenerative material in the treatment of furcation defects.

Ibandronate promotes osteogenic differentiation of periodontal ligament stem cells by regulating the expression of microRNAs

Bisphosphonates (BPs) have a profound effect on bone resorption and are widely used to treat osteoclast-mediated bone diseases. They suppress bone resorption by inhibiting the activity of mature osteoclasts and/or the formation of new osteoclasts. Osteoblasts may be an alternative target for BPs. Periodontal ligament stem cells (PDLSCs) exhibit osteoblast-like features and are capable of differentiating into osteoblasts or cementoblasts. This study aimed to determine the effects of ibandronate, a nitrogen-containing BP, on the proliferation and the differentiation of PDLSCs and to identify the microRNAs (miRNAs) that mediate these effects. The PDLSCs were treated with ibandronate, and cell proliferation was measured using the MTT (3-dimethylthiazol-2,5-diphenyltetrazolium bromide) assay. The expression of genes and miRNAs involved in osteoblastic differentiation was assayed using quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). Ibandronate promoted the proliferation of PDLSCs and enhanced the expression of alkaline phosphatase (ALP), type I collagen (COL-1), osteoprotegerin (OPG), osteocalcin (OCN), and Runx2. The expression of miRNAs, including miR-18a, miR-133a, miR-141 and miR-19a, was significantly altered in the PDLSCs cultured with ibandronate. In PDLSCs, ibandronate regulates the expression of diverse bone formation-related genes via miRNAs. The exact mechanism underlying the role of ibandronate in osteoblasts has not been completely understood. Ibandronate may suppress the activity of osteoclasts while promoting the proliferation of osteoblasts by regulating the expression of miRNAs.

The impact of cigarette smoke inhalation on the outcome of enamel matrix derivative treatment in rats: histometric analysis

BACKGROUND

Tobacco use is the most significant risk factor of periodontal disease. Clinical evidence has demonstrated that tobacco may negatively influence the results after surgical and non-surgical periodontal therapy. Enamel matrix derivative (EMD) have been used in periodontal regenerative procedures resulting in improvement of clinical parameters. The effect of EMD in the presence of tobacco compounds is unclear. Thus, the aim of the present study is to evaluate the impact of cigarette smoke inhalation (CSI) on the results of EMD treatment.

METHODS

Twenty-two Wistar rats were assigned to two groups: Group 1, CSI (n = 11); Group 2, non-exposed (n = 11). Thirty days after initiation of CSI, fenestration defects were created at the buccal aspect of the first mandibular molar. The study followed a split-mouth design. After the surgeries the defects were randomly assigned to two subgroups: non-treated control and treated with EMD. The animals were sacrificed 21 days later and the percentage of defect fill, density of newly formed bone, and new cementum formation were histometrically assessed. The number of osteoclasts was determined by tartrate-resistant acid phosphatase.

RESULTS

CSI was associated with less bone density compared to the non-exposed group. EMD provided an increased defect fill and new cementum formation in both groups. The number of tartrate-resistant acid phosphatase-positive osteoclasts was significantly higher in the CSI non-treated control group compared to the non-treated control of the non-exposed animals.

CONCLUSIONS

EMD may provide increased defect fill and cementum formation in the presence or absence of CSI. However, tobacco smoke produced a detrimental effect on bone healing when density of newly formed bone was considered.

Utility of PDL progenitors for in vivo tissue regeneration: a report of 3 cases

OBJECTIVE

Periodontal disease is an inflammatory disorder with widespread morbidities involving both oral and systemic health. The primary goal of periodontal treatment is the regeneration of the lost or diseased periodontium. In this study, we retrospectively examined feasibility and safety of reconstructing the periodontal intrabony defects with autologous periodontal ligament progenitor (PDLP) implantation in three patients.

MATERIALS AND METHODS

In this retrospective pilot study, we treated 16 teeth with at least one deep intrabony defect of probing depth (PD) > OR = 6 mm with PDLP transplantation and evaluated clinical outcome measures in terms of probing depth, gingival recession and attachment gain for a duration of 32-72 months. Furthermore, we compare PDLPs with standard PDL stem cells (PDLSCs) and confirmed that PDLPs possessed progenitor characters.

RESULTS

Clinical examination indicated that transplantationof PDLPs may provide therapeutic benefit for the periodontal defects. All treated patients showed no adverse effects during the entire course of follow up. We also found that PDLPs were analogous to PDLSCs in terms of high proliferation, expression of mesenchymal surface molecules, multipotent differentiation, and in vivo tissue regain. However, PDLPs failed to express scleraxis, a marker of tendon, as seen in PDLSCs.

CONCLUSIONS

This study demonstrated clinical and experimental evidences supporting a potential efficacy and safety of utilizing autologous PDL cells in the treatment of human periodontitis.

A double-blind randomized clinical evaluation of enamel matrix derivative proteins for the treatment of proximal class-II furcation involvements

OBJECTIVE

The aim of the present randomized, double-blind study was to evaluate the clinical response of proximal furcations treated with enamel matrix derivative proteins (EMD).

MATERIAL AND METHODS

Fifteen patients, each with a pair of contralateral class-II proximal furcation involvements, presenting probing depths (PDs) >/=5 mm and bleeding on probing (BOP) were selected. The patients were randomly assigned to: control group (n=15) - open flap debridement (OFD)+24% ethylenediaminetetraacetic acid (EDTA) conditioning; test group (n=15) - OFD+24% EDTA conditioning+EMD application. Plaque index (PI), BOP, PD, gingival margin position (GMP), relative vertical and horizontal clinical attachment level (RVCAL and RHCAL), vertical and horizontal bone level (VBL and HBL) and furcation closure were evaluated immediately before and 2, 4 and 6 months after the surgeries.

RESULTS

At 6 months, the RVCAL gains of the control and test group were 0.39 +/- 1.00 and 0.54 +/- 0.95 mm, while the RHCAL gains were 1.21 +/- 2.28 and 1.36 +/- 1.26 mm (p>0.05). The VBL and HBL gains of the control group were 1.04 +/- 1.12 and 1.00 +/- 1.79 mm, and 0.82 +/- 1.82 and 1.17 +/- 1.38 mm for the test group (p>0.05). In addition, a statistical difference was observed in the number of the remaining class-II furcations between the test and control groups (p<0.05) in this period.

CONCLUSION

It may be concluded that the use of EMD in proximal furcations did not promote a superior reduction in PD or a gain in clinical and osseous attachment levels, but resulted in a higher rate of class-II to class-I furcation conversion.

Periodontal ligament stem cell-mediated treatment for periodontitis in miniature swine

Periodontitis is a periodontal tissue infectious disease and the most common cause for tooth loss in adults. It has been linked to many systemic disorders, such as coronary artery disease, stroke, and diabetes. At present, there is no ideal therapeutic approach to cure periodontitis and achieve optimal periodontal tissue regeneration. In this study, we explored the potential of using autologous periodontal ligament stem cells (PDLSCs) to treat periodontal defects in a porcine model of periodontitis. The periodontal lesion was generated in the first molars area of miniature pigs by the surgical removal of bone and subsequent silk ligament suture around the cervical portion of the tooth. Autologous PDLSCs were obtained from extracted teeth of the miniature pigs and then expanded ex vivo to enrich PDLSC numbers. When transplanted into the surgically created periodontal defect areas, PDLSCs were capable of regenerating periodontal tissues, leading to a favorable treatment for periodontitis. This study demonstrates the feasibility of using stem cell-mediated tissue engineering to treat periodontal diseases.