Periodontal wound healing and regeneration

Early wound healing in guided bone regeneration procedures using sodium hyaluronate and a pool of amino acids: a randomized clinical trial

BACKGROUND

Soft tissue healing is of paramount importance when guided bone regeneration techniques are used, as early exposure of the membrane could affect the results.

METHODS

In this randomized clinical trial, enrolling 20 patients, a gel rich in hyaluronic acid and amino acids was used to promote wound healing after a ridge augmentation procedure. The Early Wound Healing Index - EHS was used to assess soft tissue healing by primary intention following surgery at 1, 3, 7 and 14 days.

RESULTS

Results showed faster tissue healing when hyaluronic acid mixed with amino acids was used, and also a lower perception of pain by patients measured with a VAS scale.

CONCLUSIONS

These data suggest the creation of larger research studies that can support the use of biologics for early soft tissue healing.

Acceptability of Allogeneic Mesenchymal Stromal Cell-Based Tissue Engineering for the Treatment of Periodontitis: A Qualitative Study in France

INTRODUCTION AND AIMS

Periodontitis, the main cause of tooth loss in adults, is a public health concern; its incidence increases with age, and its prevalence increases with increasing life expectancy of the population. Innovative therapies such as cell therapy represent promising future solutions for guided tissue regeneration. However, these therapies may be associated with fears and mistrust from the general public. The aim of this study was to estimate the acceptability of an advanced therapy medicinal product combining allogeneic mesenchymal stromal cells from adipose tissue with a natural fibrin hydrogel in the treatment of periodontitis.

METHODS

The methodology was based on a qualitative study conducted through semi-structured interviews with patients followed for periodontitis in the Oral Medicine Department of the Toulouse University Hospital, Toulouse, France. Qualitative studies are essential methodologies to understand the patterns of health behaviours, describe illness experiences, and design health interventions in a humanistic and person-centred way of discovering.

RESULTS

Eleven interviews (with 4 men and 7 women) were required to reach thematic saturation. Analysis allowed 4 main themes to emerge: (1) perception of new treatments, science, and caregivers; (2) conditions that the treatment must meet; (3) patient perception of the disease; and (4) factors related to the content of the treatment.

CONCLUSIONS

Patients find cell therapy for periodontitis to be acceptable. If they express a need to be informed about the benefit/risk ratio, they are not particularly worried about side effects of the treatment, for either allogeneic or blood-derived products. Periodontitis is a prototypical model of chronic inflammatory pathology and is multitissular, with hard- and soft-tissue lesions. In a patient-centred approach, the success of cell therapy will require a bilateral, informed decision, taking into account potential therapeutic effectiveness and patient expectations for regeneration.

Root surface biomodification in periodontal therapy: Biological rationale and clinical applications

Regenerative periodontal therapy aims to form new cementum, periodontal ligament, and alveolar bone, all sealed by gingival tissue. The root surface acts as the wound margin during this regeneration process. Root surface biomodification (root conditioning/root decontamination), therefore, seems instrumental in promoting surface decontamination and enhancing tissue attachment by removing the smear layer, exposing collagen fibrils, and facilitating blood clot formation and stabilization. This review attempted to provide an all-encompassing, evidence-based assessment of the role of root surface biomodification in regenerative periodontal therapy, particularly in intrabony defects, furcation defects, and root coverage procedures. The reviewed evidence suggested that root conditioning agents, whether used independently or in conjunction with bone graft materials, biological agents, membranes, or connective tissue grafts, do not offer any clinical advantage regarding clinical attachment gain. Thus, integrating chemical methods with the mechanical root instrumentation process does not necessarily contribute to superior clinical outcomes.

Early periodontal wound healing after chlorhexidine rinsing: a randomized clinical trial

OBJECTIVES

This single-center randomized, parallel design, clinical trial with a 2-week follow-up involved patients affected by periodontitis undergoing periodontal surgery. The aim was to evaluate periodontal surgical wound healing with the use of chlorhexidine-based mouth rinses versus an untreated control group.

MATERIALS AND METHODS

Periodontal surgery was performed following a standardized protocol. Patients were randomly prescribed i) chlorhexidine (CHX) + anti-discoloration system (ADS) + hyaluronic acid (HA), ii) CHX + ADS or iii) no treatment (control group). Plaque score, gingival inflammation, and Early Healing Index (EHI), assessing the degree of wound closure and the presence of fibrin and necrosis, were evaluated at 3, 7 and 14 days after surgery.

RESULTS

In total, 33 patients were enrolled. Patients were comparable at baseline for all measured clinical parameters. At 3-days wound healing was significantly improved in all patients treated with CHX + ADS-based mouth rinses with a lower EHI score at the interdental papillae compared with control group (p < 0.01). CHX + ADS + HA group presented improved healing across all time points in terms of EHI, plaque containment, and gingival inflammation when compared to control group (p < 0.01).

CONCLUSIONS

The usage of CHX-ADS following periodontal surgery improved early wound healing, reduced plaque accumulation and gingival inflammation. During the early post-operative period the adjunct of HA further improved soft tissue closure.

CLINICAL RELEVANCE

This study aims at evaluating the response of gingival tissues to mouth rinsing with chlorhexidine and anti-discoloration system (CHX + ADS) or CHX + ADS + hyaluronic acid (CHX + ADS + HA) versus no rinse in terms of healing of the periodontal surgical wound. CHX + ADS mouth rinses enhanced early soft tissue closure after periodontal surgery and contributed to the reduction in plaque accumulation and gingival inflammation. The adjunct of HA may be beneficial especially in the early post-operative period. CHX + ADS administration following periodontal surgery may improve soft tissue healing in the first two post-operative weeks.

Management of vertical bony defect using novel xenogeneic/allogeneic bone graft: A case report

BACKGROUND

Guided tissue regeneration (GTR) is a common treatment modality for correcting vertical or bony defects in furcations. Multiple materials are used in GTR with allografts and xenografts being the most widely used. Each material has distinctive properties affecting the regenerative potential. A new bone graft combination of xenogeneic/allogeneic may improve the outcome of GTR by providing space maintenance (Xenograft) and osteoinductive potential (Allograft). The aim of this case report is to evaluate the efficacy of the new combined xenogeneic/allogeneic material based on clinical and radiographic outcomes.

METHODS

A 34-year-old healthy male presented with vertical bone loss interproximally between #'s 9 and 10. Clinical exam revealed 8 mm probing depth without mobility. The radiographic exam revealed a wide and deep vertical bony defect of 30%-50% bone loss. The defect was treated using a layering technique with xenogeneic/allogeneic bone graft and collagen membrane.

RESULTS

The 6- and 12-month follow-ups revealed a significant reduction in probing depths and radiographic bone fill.

CONCLUSIONS

GTR using a layering technique of xenogeneic/allogeneic bone graft and collagen membrane showed proper correction of a deep and wide vertical bony defect. The 12-month follow-up revealed healthy periodontium with normal probing depths and bone level.

Molecular profiling of gingival crevicular fluid fails to distinguish between infrabony and suprabony periodontal defects

AIM

To assess the differential molecular profiling of gingival crevicular fluid (GCF) from infrabony and suprabony periodontal defects compared with healthy sites.

MATERIALS AND METHODS

Seventy-five samples from 25 patients with untreated periodontitis stage III-IV were included. Clinical and radiological parameters as well as GCF samples were collected from an infrabony defect, a suprabony defect and a periodontally healthy site per patient. A multiplex bead immunoassay was performed to assess the level of 18 biomarkers associated with inflammation, connective tissue degradation and regeneration/repair.

RESULTS

GCF volume was higher in periodontal sites compared with healthy sites, with no significant difference between infrabony and suprabony defects. Fourteen biomarkers were elevated in infrabony and suprabony sites compared with healthy sites (p < .05). Only interleukin-1α levels were increased in infrabony compared with suprabony sites, whereas there was no difference in probing pocket depth.

CONCLUSIONS

Although the GCF molecular profile clearly differentiates periodontally affected sites from healthy sites, the different architecture between infrabony and suprabony defects is not reflected in GCF biomarker changes.

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.

Periodontal Healing with Fixed Restorations Using the Biologically Oriented Preparation Technique Combined with a Full Digital Workflow: A Clinical Case Report

(1) Gingival inflammation is an ongoing challenge in tooth-supported fixed restorations, especially when the prosthetic margin does not consider the supracrestal tissues of patients. This case report aimed to present the case of a patient who was periodontally compromised due to a previous invasion of the supracrestal tissue attachment with fixed restorations and evaluate the healing response of periodontal tissues to a vertical edgeless preparation technique: bleeding upon probing (BOP), periodontal probing depth (PPD) and clinical attachment level (CAL). (2) After tooth preparation, the new restorations were adapted, this time without invading the supracrestal space of the patient, and CAD/CAM monolithic zirconia crowns were fabricated. (3) Optimal maturation of the soft tissue was observed, achieving correction of the marginal contour of periodontal tissues and improvement of periodontal indexes. (4) It can be concluded that the BOPT technique combined with a full digital workflow is a valid option for the correction and remodeling of gingival architecture.

Underestimated microbial infection of resorbable membranes on guided regeneration

Barrier membranes are critical in creating tissuecompartmentalization for guided tissue (GTR) and bone regeneration (GBR) therapies. More recently, resorbable membranes have been widely used for tissue and bone regeneration due to their improved properties and the dispensable re-entry surgery for membrane removal. However, in cases with membrane exposure, this may lead to microbial contamination that will compromise the integrity of the membrane, surrounding tissue, and bone regeneration, resulting in treatment failure. Although the microbial infection can negatively influence the clinical outcomes of regenerative therapy, such as GBR and GTR, there is a lack of clinical investigations in this field, especially concerning the microbial colonization of different types of membranes. Importantly, a deeper understanding of the mechanisms of biofilm growth and composition and pathogenesis on exposed membranes is still missing, explaining the mechanisms by which bone regeneration is reduced during membrane exposure. This scoping review comprehensively screened and discussed the current in vivo evidence and possible new perspectives on the microbial contamination of resorbable membranes. Results from eligible in vivo studies suggested that different bacterial species colonized exposed membranes according to their composition (collagen, expanded polytetrafluoroethylene (non-resorbable), and polylactic acid), but in all cases, it negatively affected the attachment level and amount of bone gain. However, limited models and techniques have evaluated the newly developed materials, and evidence is scarce. Finally, new approaches to enhance the antimicrobial effect should consider changing the membrane surface or incorporating long-term released antimicrobials in an effort to achieve better clinical success.

Assessment of early wound healing, pain intensity, quality of life and related influencing factors during periodontal surgery: a cross-sectional study

BACKGROUND

This cross-sectional study assessed early wound healing, pain intensity, quality of life, surgical satisfaction, and related factors during periodontal surgery.

METHODS

A total of 369 patients completed the questionnaire before undergoing periodontal surgery (baseline), immediately after the operation (phase I), on the day of suture removal (phase II), and one month later (phase III). The Early Wound Healing Score (EHS) was assessed, and the short-form McGill Pain Questionnaire (SF-MPQ), tooth hypersensitivity visual analog scale (VAS), oral health-related quality of life measure (OHQoL-UK), and surgical satisfaction VAS were administered and analysed.

RESULTS

The EHS was 8.41 ± 2.74 and was influenced by disease severity and surgical factors. Scores on the SF-MPQ, pain intensity scores, and OHQoL-UK scores were significantly increased in phase I and decreased later. Tooth sensitivity decreased significantly one month after periodontal surgery. Psychological factors were positively related to SF-MPQ, pain intensity, OHQoL-UK and tooth sensitivity VAS scores in all phases, while disease severity and surgical factors were only related to these scores at baseline or in phases I/II/III. Surgical acceptance and reoperation willingness continuously decreased after surgery, and all these scores were related to surgical satisfaction.

CONCLUSIONS

EHS, pain intensity and quality of life were closely related to disease severity, psychological factors and surgical factors in phase I (i.e., immediately after surgery). The findings suggest that surgical details should be enhanced and that behavioural and psychological interventions measures should be implemented to improve outcomes during periodontal operation and during the early postoperative period as well as to improve patient-oriented periodontal surgery experiences. Trial registration This cross-sectional study did not include interventions with human participants, and all the experimental procedures involving humans in this study were approved by the Ethics Committee of West China College of Stomatology, Sichuan University (WCHSIRB-D-2020-284).

Digital photometric analysis of gingival response to periodontal treatment

OBJECTIVES

The color is a major factor in determining inflammation status in most gingival indices. Current indices have limitations mainly due to subjective nature. Digital color analysis can provide objective and accurate measurements. Thus, the present study aimed to assess by digital tool the gingival color in the different stages of an active periodontal treatment.

METHODS

Forty patients (19 males and 21 females) diagnosed with periodontitis (stage III/ IV, grade C) and treated surgically were included in the study. Clinical data (probing depth, bleeding on probing, clinical attachment level, gingival index, and gingival recession) and photographs by digital single-lens-reflex (DSLR) camera were recorded before initial periodontal treatment, which included scaling and root surface debridement (T0); the same parameters were then re-evaluated 6-8 weeks (T1) and 3 months after periodontal surgery (regenerative/resective) (T2). Differences between clinical parameters were calculated. The color space defined by the International Commission on Illumination (CIELab) was used to analyze gingival color.

RESULTS

In 56 periodontal surgical sites, 168 photographs were taken. The a*-value of the CIELab color system (higher a*- value translate to a stronger red color) was significantly reduced between T0 to T1 and further decreased at T2 (32.01, 29.28, and 27.45 respectively). Significant improvement in clinical parameters were found between T0 to T1 and T1 to T2. Sub-analysis of two distinct surgical interventions revealed that only regenerative procedure improved the a*-value, which was significantly correlated with pocket depth reduction.

CONCLUSIONS

Photometric analysis can be used to assess gingival color change during periodontal treatment of patients with periodontitis.

CLINICAL SIGNIFICANCE

Gingival inflammation is a major factor in periodontal assessment; nevertheless, all current gingival inflammation indices are partially subjective and only semi-quantitative. The digital photometric analysis may allow for accurate and objective gingival color assessment during periodontal treatment.

RGD Nanoarrays with Nanospacing Gradient Selectively Induce Orientation and Directed Migration of Endothelial and Smooth Muscle Cells

Directed migration of cells through cell-surface interactions is a paramount prerequisite in biomaterial-induced tissue regeneration. However, whether and how the nanoscale spatial gradient of adhesion molecules on a material surface can induce directed migration of cells is not sufficiently known. Herein, we employed block copolymer micelle nanolithography to prepare gold nanoarrays with a nanospacing gradient, which were prepared by continuously changing the dipping velocity. Then, a self-assembly monolayer technique was applied to graft arginine-glycine-aspartate (RGD) peptides on the nanodots and poly(ethylene glycol) (PEG) on the glass background. Since RGD can trigger specific cell adhesion via conjugating with integrin (its receptor in the cell membrane) and PEG can resist protein adsorption and nonspecific cell adhesion, a nanopattern with cell-adhesion contrast and a gradient of RGD nanospacing was eventually prepared. In vitro cell behaviors were examined using endothelial cells (ECs) and smooth muscle cells (SMCs) as a demonstration. We found that SMCs exhibited significant orientation and directed migration along the nanospacing gradient, while ECs exhibited only a weak spontaneously anisotropic migration. The gradient response was also dependent upon the RGD nanospacing ranges, namely, the start and end nanospacings under a given distance and gradient. The different responses of these two cell types to the RGD nanospacing gradient provide new insights for designing cell-selective nanomaterials potentially used in cell screening, wound healing, etc.

Challenges and tissue engineering strategies of periodontal guided tissue regeneration

Periodontitis is a chronic infectious oral disease with a high prevalence rate in the world, and is a major cause of tooth loss. Nowadays, people have realized that the local microenvironment that includes proteins, cytokines, and extracellular matrix has a key influence on the functions of host immune cells and periodontal ligament stem cells during a chronic infectious disease such as periodontitis. The above pathological process of periodontitis will lead to a defect of periodontal tissues. Through the application of biomaterials, biological agents, and stem cells therapy, guided tissue regeneration (GTR) makes it possible to reconstruct healthy periodontal ligament tissue after local inflammation control. To date, substantial advances have been made in periodontal guided tissue regeneration. However, the process of periodontal remodeling experiences complex microenvironment changes, and currently periodontium regeneration still remains to be a challenging feat. In this review, we summarized the main challenges in each stage of periodontal regeneration, and try to put forward appropriate biomaterial treatment mechanisms or potential tissue engineering strategies that provide a theoretical basis for periodontal tissue engineering regeneration research.

Genomic Medicine in Periodontal Disease: Old Issue, New Insights

Genetic variability is the main cause of phenotypic variation. Some variants may be associated with several diseases and can be used as risk biomarkers, identifying animals with higher susceptibility to develop the pathology. Genomic medicine uses this genetic information for risk calculation, clinical diagnosis and prognosis, allowing the implementation of more effective preventive strategies and/or personalized therapies. Periodontal disease (PD) is the inflammation of the periodontium induced mainly by bacterial plaque and is the leading cause of tooth loss. Microbial factors are responsible for the PD initiation; however, several studies support the genetic influence on the PD progression. The main purpose of the present publication is to highlight the main steps involved in the genomic medicine applied to veterinary patients, describing the flowchart from the characterization of the genetic variants to the identification of potential associations with specific clinical data. After investigating which genes might potentially be implicated in canine PD, the RANK gene, involved in the regulation of osteoclastogenesis, was selected to illustrate this approach. A case-control study was performed using DNA samples from a population of 90 dogs – 50 being healthy and 40 with PD. This analysis allowed for the discovery of four new intronic variations that were banked in GenBank (g.85A>G, g.151G>T, g.268A>G and g.492T>C). The results of this study are not intended to be applied exclusively to PD. On the contrary, this genetic information is intended to be used by other researchers as a foundation for the development of multiple applications in the veterinary clinical field.

Bioinformatic Analysis Reveals Hub Immune-Related Genes of Diabetic Foot Ulcers

Diabetic foot ulcer (DFU) is a complex and devastating complication of diabetes mellitus that are usually stagnant in the inflammatory phase. However, oral wound healing, which is characterized by a rapid and scarless healing process, is regarded an ideal model of wound healing. Thus, we performed a comprehensive bioinformatics analysis of the previously published data regarding oral ulcers and DFUs and found that compared to oral wound healing, the activated pathways of DFUs were enriched in cellular metabolism-related pathways but lacked the activation of inflammatory and immune-related pathways. We also found that CXCL11, DDX60, IFI44, and IFI44L were remarkable nodes since they had the most connections with other members of the module. Meanwhile, CXCL10, IRF7, and DDX58 together formed a closed-loop relationship and occupied central positions in the entire network. The real-time polymerase chain reaction and western blot was applied to validate the gene expression of the hub immune-related genes in the DFU tissues, it was found that CXCL11, IFI44, IFI44L, CXCL10 and IRF7 have a significant difference compared with normal wound tissues. Our research reveals some novel potential immune-related biomarkers and provides new insights into the molecular basis of this debilitating disease.

Periodontal Wound Healing and Regeneration: Insights for Engineering New Therapeutic Approaches

Periodontitis is a widespread inflammatory disease that leads to loss of the tooth supporting periodontal tissues. The few therapies available to regenerate periodontal tissues have high costs and inherent limitations, inspiring the development of new approaches. Studies have shown that periodontal tissues have an inherent capacity for regeneration, driven by multipotent cells residing in the periodontal ligament (PDL). The purpose of this review is to describe the current understanding of the mechanisms driving periodontal wound healing and regeneration that can inform the development of new treatment approaches. The biologic basis underlying established therapies such as guided tissue regeneration (GTR) and growth factor delivery are reviewed, along with examples of biomaterials that have been engineered to improve the effectiveness of these approaches. Emerging therapies such as those targeting Wnt signaling, periodontal cell delivery or recruitment, and tissue engineered scaffolds are described in the context of periodontal wound healing, using key in vivo studies to illustrate the impact these approaches can have on the formation of new cementum, alveolar bone, and PDL. Finally, design principles for engineering new therapies are suggested which build on current knowledge of periodontal wound healing and regeneration.

Immuno-histopathologic evaluation of mineralized plasmatic matrix in the management of horizontal ridge defects in a canine model (a split-mouth comparative study)

Our research aimed to investigate the effect of combining biphasic calcium phosphate (BCP) alloplast with mineralized plasmatic matrix (MPM) as compared with platelet-rich fibrin (PRF) on the quality and quantity of bone formation and maturation at surgically created horizontal critical-sized ridge defects (HRDs) in a canine model. We used a split-mouth design using the third and fourth mandibular premolars of the mongrel dogs. Twelve defects on the left side (experimental group, I) were managed with MPM composite mixed with BCP alloplast, MPM compact layer. On the right side (control group, II), another 12 defects were managed with PRF mixed with BCP alloplast, followed by the application of PRF compact strips. Finally, both were covered by a collagen membrane. Dogs were euthanized at 4, 8, and 12 weeks, and the studied defects were processed to evaluate treatment outcome, including mean percentage of bone surface area, collagen percentage, and osteopontin (OPN) immunoreaction. Our results revealed that the mean percentage of bone surface area was significantly increased in the experimental group treated with MPM at all time intervals as compared with the PRF group. Decreased collagen percentage and increased OPN immunoreactivity showed significant results in the MPM group as compared with PRF at 4 and 8 weeks postoperatively, respectively. In conclusion, MPM accelerates the formation of superior new bone quality when used in the treatment of HRDs.

Wound healing in periodontal disease induces macrophage polarization characterized by different arginine-metabolizing enzymes

BACKGROUND AND OBJECTIVE

Macrophages play important roles from the initiation of inflammation to wound healing. Two phenotypes of macrophages, namely pro-inflammatory type macrophages (M1-MΦ) and anti-inflammatory type macrophages (M2-MΦ), have been reported. Two contrasting metabolic enzymes that use arginine as a substrate, inducible nitric oxide synthase (iNOS), and arginase-1 (Arg-1), have been identified as M1-MΦ and M2-MΦ markers, respectively. The purpose of this study was to elucidate the temporal dynamics of the macrophage phenotype during the progression and healing phases of experimental periodontitis in mice.

MATERIAL AND METHODS

A total of 63 C57BL/6J mice were divided into the following 3 groups: control (C), periodontitis (P), and healing (H). To induce periodontitis, a silk ligature was placed around the maxillary bilateral second molars of mice in the periodontitis and healing groups. In the healing group, the ligature was removed 3 days after ligation to induce tissue healing. Maxillary tissue was collected on day 0 for the control group, days 1, 3, 5, and 7 for the periodontitis group (P1, P3, P5, and P7), and days 5 and 7 for the healing group (H5 and H7: 3 days with the ligation + 2 days or 4 days following ligature removal). The left side of the maxilla was subjected to bone structure analysis using micro-computed tomography and gene expression analysis using polymerase chain reaction. On the right side, immunohistochemistry was performed to histopathologically evaluate the localization of macrophages by phenotype in the periodontal tissue.

RESULTS

In the alveolar bone structure analysis, the linear distance of bone height increased significantly in the P5 and P7 groups, whereas bone volume fraction and bone mineral density decreased over time after ligature placement; in the healing group (H5 and H7), these parameters improved significantly compared with the periodontitis group (P5 and P7). Expression of genes encoding pro-inflammatory cytokines and iNOS increased in the periodontitis group, and expression of anti-inflammatory cytokine genes and Arg-1 increased in the healing group. Furthermore, the iNOS/Arg-1 expression ratio increased with ligation, whereas the ratio in the healing groups (H5 and H7) significantly decreased compared with the periodontitis groups (P5 and P7). Immunofluorescence staining revealed a significant increase in the number of iNOS-positive macrophages in the periodontitis group and decrease in the healing group. In contrast, the number of Arg-1-positive macrophages decreased in the periodontitis group and increased in the healing group.

CONCLUSION

The results of the present study suggest that wound healing in periodontal disease induces macrophage polarization from M1-MΦ to M2-MΦ characterized by iNOS and Arg-1.

Risk Factors for Failure of Hard Palate Mucoperiosteal Flap Repair of Acquired Oronasal Communication in Dogs: A Pilot Study

The objective of this retrospective pilot study was to describe potential risk factors for failure of hard palate mucoperiosteal flaps (HPF) transposed for closure of oronasal communication. Dogs (n = 28) with acquired oronasal communication defects were included in the study population. Functional success of an HPF was determined by visual inspection at the last examination and lack of clinical signs. Risk factors for HPF failure including age, sex, body weight, presence of neoplasia at the time of surgery, presence of neoplasia after surgery due to incomplete or narrow margins, use of CO₂ laser, previous surgeries in the same location, HPF blood supply, size of the HPF as a percentage of the total area of the hard palate mucoperiosteum, and distance traveled by the apex of the HPF were evaluated using descriptive statistics and unadjusted logistic regression modeling. Seven out of 28 (25%) hard palate flap procedures resulted in persistent oronasal communication and were considered failures. Body weight (Median: 17 vs. 25 kg, OR = 0.94, 80% CI = 0.90, 0.99), presence of neoplasia at the time of surgery (86 vs. 57%, OR = 4.50, 80% CI = 1.01, 20.06), HPF area (Median: 0.49 vs. 0.41, OR = 84.40, 80% CI = 1.66, 4,298) and apex travel distance (Median: 2.06 vs. 0.67, OR = 5.15, 80% CI = 2.14, 12.38) were associated with flap failure. Within this sample, the presence of neoplasia at the time of initial surgery, increasing the area of the HPF, and distance traveled by the HPF apex were associated with a greater odds of HPF failure. Further studies with larger sample sizes are needed to confirm repeatability of these results. HPFs remain a viable surgical option for closure of oronasal communication. Careful surgical planning, strict adherence to surgical principles, and awareness of anatomical limitations can increase the likelihood of success.

The Evolution of Surgical Techniques and Biomaterials for Periodontal Regeneration

The understanding of biological concepts in wound healing together with the evolution in biomaterials applied in periodontal regeneration allowed for improved, minimally invasive surgical techniques with a wider range of application and adapted to achieve multiple goals at the same time. Regenerating attachment was never the sole end point, but maintaining the patient's own natural dentition in health and esthetics is becoming a feasible goal even in cases considered challenging just a few years ago. In this article we report on the evolution of techniques and biomaterials and their application in esthetic and challenging cases.

Autologous platelet-rich fibrin as an adjunct to non-surgical periodontal therapy-A follow up clinical pilot study

The aim was to evaluate the effectiveness of autologous platelet-rich fibrin (PRF) as an adjunct to scaling and root planing (SRP) in moderate periodontal pockets. The split-mouth study involved 32 sites from 16 patients. Baseline parameters were recorded followed by complete full-mouth SRP. The test and control sites were randomly selected and autologous PRF was placed in the test site and other site served as control. The blinded examiner recorded clinical parameters at baseline, 60 days, and 90 days. No statistical significance was found at baseline in probing depth (PD) and clinical attachment level (CAL). Statistically, significant improvement was observed within test and control groups at 90 days compared to baseline values. A statistically significant difference in test sites was found in terms of reduction in PD and clinical attachment gain (CAG) compared to the control sites at the end of the study period (p value <0.05). This split-mouth pilot study emphasized a statistically significant improvement in pocket depth reduction and CAL gain when PRF was used as an adjunct to SRP in moderate periodontal pockets.

Combination of enamel matrix derivative and hyaluronic acid inhibits lipopolysaccharide-induced inflammatory response on human epithelial and bone cells

Objectives

The aim of this study was to evaluate the in vitro effect of enamel matrix derivative (EMD) and hyaluronic acid (HA) and their synergistic combination on lipopolysaccharides (LPS)-induced inflammation in human keratinocytes and osteoblasts.

Material and methods

Cells were challenged with LPS (1 μg/ml) and cultured in the following treatment groups with EMD (30 mg/ml) and HA (30 mg/ml): LPS, EMD, HA, EMD + HA, EMD + LPS, HA + LPS, and EMD + HA + LPS. Cell viability, inflammatory cytokine expression, and cell migration were determined using colorimetric assay, quantitative real-time polymerase chain reaction (qPCR), and scratch wound healing assay, respectively.

Results

Cell viability was decreased when exposed to LPS compared to the controls. Overall, LPS treatment expressed upregulation on inflammatory cytokine tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6). EMD and HA reduced up to 3.0-fold the cytokine expression caused by LPS (p < 0.05). EMD and HA statistically induced higher migration in osteoblasts and keratinocytes, respectively. Migration was impaired by LPS, whereas it significantly increased after addition of EMD and HA.

Conclusions

EMD and HA are advantageous biomaterials that individually generate strong directional migratory keratinocyte and osteoblast response. Their combination also enhances cell viability, and anti-inflammatory and migratory abilities to promote healing specially under LPS inflammatory stimulus. Future in vivo and animal research is necessary to further characterize the effect of EMD and HA on periodontal regeneration.

Clinical relevance

The use of EMD in conjunction with HA resulted in a reduction of inflammation and improvement of tissue healing at wound sites. Both biomaterials combined may potentially improve the effectiveness of bone regeneration in periodontal bone defects, pointing to the potential clinical relevance of both materials in regenerative periodontal surgery.

Use of platelet-rich fibrin for the treatment of periodontal intrabony defects: a systematic review and meta-analysis

Objectives

This study aims to compare the treatment outcomes of periodontal intrabony defects by using platelet-rich fibrin (PRF) with other commonly utilized modalities.

Materials and methods

The eligibility criteria comprised randomized controlled trials (RCTs) comparing the clinical outcomes of PRF with that of other modalities. Studies were classified into 10 categories as follows: (1) open flap debridement (OFD) alone versus OFD/PRF; (2) OFD/bone graft (OFD/BG) versus OFD/PRF; (3) OFD/BG versus OFD/BG/PRF; (4–6) OFD/barrier membrane (BM), OFD/PRP, or OFD/enamel matrix derivative (EMD) versus OFD/PRF; (7) OFD/EMD versus OFD/EMD/PRF; (8–10) OFD/PRF versus OFD/PRF/metformin, OFD/PRF/bisphosphonates, or OFD/PRF/statins. Weighted means and forest plots were calculated for probing depth (PD), clinical attachment level (CAL), and radiographic bone fill (RBF).

Results

From 551 articles identified, 27 RCTs were included. The use of OFD/PRF statistically significantly reduced PD and improved CAL and RBF when compared to OFD. No clinically significant differences were reported when OFD/BG was compared to OFD/PRF. The addition of PRF to OFD/BG led to significant improvements in CAL and RBF. No differences were reported between any of the following groups (OFD/BM, OFD/PRP, and OFD/EMD) when compared to OFD/PRF. No improvements were also reported when PRF was added to OFD/EMD. The addition of all three of the following biomolecules (metformin, bisphosphonates, and statins) to OFD/PRF led to statistically significant improvements of PD, CAL, and RBF.

Conclusions

The use of PRF significantly improved clinical outcomes in intrabony defects when compared to OFD alone with similar levels being observed between OFD/BG and OFD/PRF. Future research geared toward better understanding potential ways to enhance the regenerative properties of PRF with various small biomolecules may prove valuable for future clinical applications. Future research investigating PRF at histological level is also needed.

Clinical relevance

The use of PRF in conjunction with OFD statistically significantly improved PD, CAL, and RBF values, yielding to comparable outcomes to OFD/BG. The combination of PRF with bone grafts or small biomolecules may offer certain clinical advantages, thus warranting further investigations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-03825-8.

Minimally Invasive Surgical Strategies in Regenerative/Reconstructive Periodontal Therapy

FOCUSED CLINICAL QUESTION

After a quick overview on the original principles of guided periodontal regeneration (GTR), the aim of this paper focuses on the advantages of minimally invasive surgical techniques for periodontal regeneration/reconstruction. The specific clinical question to answer is: Are there new clinical parameters useful to choose the best minimal invasive surgery approach for each periodontal defect? An update of the decision trees is to propose after highlighting some clinical parameters deemed relevant for the choice of the most suitable minimally invasive surgical approach and which therefore are considered by us having a place in the new decision trees.

SUMMARY

Starting from the paper of Evian dated 1985 until that of Aslan in 2017, we have analyzed the minimal periodontal surgical techniques proposed for the periodontal regeneration. In addition to the parameters set in the various flowcharts, we have highlighted the following additional parameters: papilla height loss; supra bone component of the defect; Δ Bone Sounding; width of keratinized tissue.

CONCLUSION

The decision-making chart improved with the new clinically relevant factors may serve as a useful guideline for dentists, but to definitively validate it, further studies need to be developed in the future. In order to clarify the proposed flow chart, the authors present two different clinical cases.

Comparative Assessment of the Antioxidant Activities among the Extracts of Different Parts of Clausena lansium (Lour.) Skeels in Human Gingival Fibroblast Cells

Clausena lansium (Lour.) Skeels (wampee) is an outstanding natural plant with medicinal properties. The aim of this study was to compare the cytoprotective effects of four parts of wampee under oxidative stress. The aqueous extracts of leaf, peel, pulp, and seed were tested for the proliferation effects on human gingival fibroblast (HGF) cells and the protective effects in the hydrogen peroxide-induced HGF model. Furthermore, the total glutathione assay and identification of rutin by high-performance liquid chromatography were carried out to attempt to determine whether the cytoprotective effects were related to the total glutathione (GSH) stability and rutin content. The results showed that all of the extracts had no cytotoxicity to HGF at tested concentrations ranging from 50 to 5000 μg/ml during 24 h, and the leaf, pulp, and seed extracts increased proliferation of HGF at relatively high concentrations. All the extracts except for the seed extract significantly decreased the production of reactive oxygen species, and the peel extracts exhibited the most effective antioxidant effect. The leaf extract had the highest anticytotoxicity and GSH stabilization effect in the HGF challenged with hydrogen peroxide. In addition, the relative content of rutin in peel and leaf extracts was higher than that in pulp and seed. The results of GSH assay and rutin identification suggest that different cellular protective effects among the four parts of wampee are partially related to the GSH stabilization and rutin content. These findings provide a scientific basis for the antioxidant effect-related biological activities of wampee extracts.

Expression of inflammatory biomarkers and growth factors in gingival crevicular fluid at different healing intervals following non-surgical periodontal treatment: A systematic review

BACKGROUND

Non-surgical periodontal treatment (NSPT) is widely employed for the treatment of periodontal disease and yields significant clinical improvements. Gingival crevicular fluid (GCF) can be used to profile health and disease, and recent technological advances, such as multiplex bead immunoassays, are promising in identifying a wider array of GCF factors with the ultimate aim to predict the treatment response.

OBJECTIVE

The aim of this systematic review was to compare the expression of GCF markers using multiplex bead immunoassays before treatment and during early, average, or late healing period, following non-surgical periodontal treatment (NSPT).

METHODS

An electronic literature search was conducted by two independent examiners (VK and NC) in MEDLINE, EMBASE, OpenGrey, LILACS, and Cochrane Library up to January 2020. The PICO question formulated was as follows: "In patients with periodontal disease, does the expression of gingival crevicular fluid (GCF) markers detected using multiplex bead immunoassay differ at baseline compared with early (≤30 days), average (6-8 weeks), or late (≥3 months) healing after intervention?"

RESULTS

A total of 366 publications were obtained and reviewed for eligibility for inclusion. Of these, 12 publications fulfilled the inclusion criteria and were included in the present review. Data for a total of 31 different GCF markers were extracted and summarized for early, average, or late healing after NSPT. Early healing following NSPT (≤ 30 days) indicated an increase in IL-1β, TNFα, and IL-10. At the average healing period (6-8 weeks), IL-1β, IL-1α, IL-6, TNF-α, IFN-γ, GM-CSF, MCP-1, and MIP-1α were all reduced, compared to their respective baseline values. Three months after NSPT, IL-1β, IL-4, IL-6, IL-10, TNF-α, and IFN-γ were detected at reduced levels, compared to pre-treatment levels. Overall, the changes following treatment indicated a reduction of inflammation present at baseline.

CONCLUSION

Following non-surgical periodontal treatment, an upregulation of inflammation markers is noted early post-operatively and a subsequent reduction of their levels three months following treatment. The investigation of levels of GCF markers associated with inflammation and regeneration, especially using multiplex bead immunoassay technologies, is a valuable tool to better understand the processes associated with healing following periodontal treatment.

Healing of periodontal suprabony defects following treatment with open flap debridement with or without an enamel matrix derivative: A randomized controlled clinical study

OBJECTIVES

To compare the healing of suprabony defects following treatment with either open flap debridement (OFD) and application of an enamel matrix derivative (EMD) with OFD alone.

METHODS

Eighty patients with suprabony periodontal defects were randomly assigned to treatment with OFD + EMD (test) or OFD alone (control). The primary outcome variable was the difference in clinical attachment level (CAL) gain. At baseline and after 12 months, full-mouth plaque scores (FMPS), full-mouth bleeding scores (FMBS), probing depths (PD), gingival recessions (GR), and CAL were recorded.

RESULTS

Sixty-five patients were available for the 12-month follow-up examination. At 12 months, the mean FMPS was 21.9 ± 3.0% in the OFD + EMD and 21.1 ± 2.4% in the OFD group, respectively (p = 0.30), while mean FMBS measured 20.4 ± 3.4% in the OFD + EMD group and 19.9 ± 2.9% in the OFD group (p = 0.48). Mean CAL gain at sites treated with OFD + EMD was statistically significantly different (p = 0.0001) compared with sites treated with OFD alone (3.4 ± 0.6 mm vs 1.8 ± 0.6 mm). A statistically significant difference (p = 0.0001) was found between mean PD change in the OFD + EMD (3.9 ± 0.6 mm) and OFD alone (3.2 ± 0.6 mm) treated groups and also in terms of mean GR change between treatment with OFD + EMD (0.5 ± 0.7 mm) and OFD alone (1.4 ± 1.0 mm) (p = 0.001).

CONCLUSION

Within their limits, the present results indicate that in suprabony periodontal defects, the application of EMD in conjunction with OFD may additionally improve the clinical outcomes compared with OFD alone.

CLINICAL RELEVANCE

In periodontal suprabony defects, the application of EMD in conjunction with OFD may additionally enhance the clinical outcomes in terms of CAL gain and PD reduction.

Comparative evaluation of the effect of curcumin and chlorhexidine on human fibroblast viability and migration: An in vitro study

Background and Objective:

Chemical plaque control acts as an adjunct to mechanical periodontal therapy. Chlorhexidine (CHX) is considered as the gold standard in chemical plaque control, but the main concern is about its fibroblast cytotoxicity. Curcumin, a lipophilic polyphenol, may offer as a promising antiplaque agent. This study was conducted to compare the effect of curcumin (0.003%, 0.03%, 0.06%, 0.1%, and 0.12%) and CHX (0.03%, 0.06%, 0.1%, 0.12%, and 0.2%) on gingival fibroblast cell viability and wound healing at different time periods (1, 2, 4, 6, 8, and 10 min).

Materials and Methods:

The minimum inhibitory concentration (MIC50) was determined before the evaluation of cytotoxicity and wound healing property. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and morphological examination by direct invert microscopy were carried out to determine cytotoxicity. Wound healing was evaluated by scratch wound assay.

Results and Discussion:

The MIC50 of CHX and curcumin was at 0.1% and 0.003%, respectively. The mean percentage of fibroblast viability at different concentrations of CHX and curcumin at each time period showed a significant difference. Curcumin exhibited less cytotoxicity as compared to CHX at all concentrations and at varying time periods. There was a significant difference between mean percentage of fibroblast viability at MIC50 of CHX (0.1%) and curcumin (0.003%) at different time periods. The difference between percentage wound healing at antibacterial concentrations of CHX and curcumin at varying time periods was significant.

Conclusion:

The antibacterial concentration of curcumin (0.003%) exhibits less fibroblast cytotoxicity and excellent wound healing property as compared to CHX. Curcumin may offer as a promising chemical plaque control agent which is less cytotoxic, cost-effective, safe, easily available, and with a possibly beneficial effect on wound healing.

Single-Flap Approach in Periodontal Regeneration for Intraosseous Defects: Case Series

INTRODUCTION

A single-flap approach (SFA) is the elevation of a periodontal flap to access the defect only from one side. Several studies have reported that the SFA is at least as clinically effective as the elevation of a flap at both buccal and palatal/lingual aspects. However, studies regarding the SFA have reported only 6 to 10 months follow-up clinical outcomes. The purpose of this case series was to investigate the outcomes of the SFA for periodontal regeneration with a collagen membrane and bone grafts in regard to linear bone defect fill and clinical parameters such as gingival recession (GR), pocket depth (PD), and clinical attachment level (CAL) for the 15-month follow-up.

CASE SERIES

Based on the deepest pocket depth site, the flap retraction side for each case, either buccal or palatal/lingual, was determined. After retraction of a one-side full thickness flap, complete removal of granulation tissue and thorough scaling and root planing were performed. Demineralized ground cortical bone grafts were gently packed into the defect areas and an absorbable collagen membrane was placed over the grafts in 13 cases from 11 patients.

CONCLUSION

This case series demonstrated that the SFA for periodontal regeneration with a collagen membrane and bone grafts resulted in decreased PD with minimum GR, gain in CAL, and bone fill at defect sites for the 15-month follow-up.

Periodontal regeneration using bone morphogenetic protein 2 incorporated biomimetic calcium phosphate in conjunction with barrier membrane: A pre-clinical study in dogs

Aim

To evaluate the effect of bone morphogenetic protein 2 (BMP‐2) incorporated biomimetic calcium phosphate (BMP‐2/BioCaP) in conjunction with barrier membrane on periodontal regeneration in chronic periodontitis experimental model.

Material and Methods

Chronic periodontitis experimental model with critical‐sized supra‐alveolar defects was created in 15 dogs’ mandibles. After the initial periodontal therapy, the defects were randomly assigned to the following groups: (a) control; (b) barrier membrane; (c) deproteinized bovine bone mineral + barrier membrane; (d) BioCaP + barrier membrane and (e) BMP‐2/BioCaP + barrier membrane (6 quadrants with 18 teeth per group). Eight weeks later, clinical examinations, micro‐CT, and histomorphometric analyses were performed.

Results

Clinical examinations, including plaque index, bleeding index, and probing depth, were similar for all groups. In contrast, the clinical attachment loss was significantly lower in defects grafted with BMP‐2/BioCaP and barrier membrane. The micro‐CT results showed that the height of mineralized tissue in defects grafted with BMP‐2/BioCaP and barrier membrane was significantly higher. For histometric analysis, the defects grafted with BMP‐2/BioCaP and barrier membrane exhibited significantly more connective tissue height, new cementum height, new bone height and area, as well as less down‐growth of junctional epithelium.

Conclusion

BMP‐2/BioCaP could be a promising bone substitute for periodontal regeneration.

Early Wound Healing Score (EHS): An Intra- and Inter-Examiner Reliability Study

The early wound healing score (EHS) was introduced to assess early wound healing of periodontal soft tissues after surgical incision. The purpose of this study is to evaluate the intra- and inter-examiner reliability of the EHS. Six examiners with different levels of training and clinical focus were enrolled. Each examiner was trained on the use of the EHS before starting the study. Thereafter, 63 photographs of three different types of surgical incisions taken at day 1, 3 or 7 post-operatively were independently evaluated according to the proposed assessment method. A two-way random intra-class correlation coefficient (ICC) and 95% confidence interval (CI) were used to analyze the intra- and inter-examiner reliability for the EHS. The inter-examiner reliability for the EHS was 0.828 (95% CI: 0.767–0.881). The intra-examiner reliability ranged between 0.826 (95% CI: 0.728–0.891) and 0.915 (95% CI: 0.856–0.950). The results therefore show an “almost perfect agreement” for intra- and inter-examiner reliability. The EHS provides a system for reproducible repeated ratings for the early healing assessment of incisions of periodontal soft tissues. Even when used by examiners with different clinical experience and specialty, it shows a high correlation coefficient.

Retro MTA and tricalcium phosphate/retro MTA for guided tissue regeneration of periodontal dehiscence defects in a dog model: a pilot study

Objectives

Retro MTA is a fast setting Calcium silicate cement used in endodontic regeneration procedures in recent years. Beta-tricalcium phosphate (β-TCP) is another common biomaterial used for bone augmentation procedures. The present pilot study was undertaken to evaluate and compare the efficacy of Retro MTA and a mixture of Retro MTA / β-TCP for periodontal tissue regeneration.

Materials and methods

In 4 beagle dogs, periodontal dehiscence type defects were created. In each side, one dehiscence defect was left empty as a control site and three treatment modalities were randomly applied for the others: Retro MTA covered with a collagen membrane, Retro MTA + β-TCP covered with a membrane and covering the defect with a membrane without any bone augmentation. After 8 weeks Animals were sacrificed and Histomorphometric and histologic analysis were conducted.

Results

Histologic analysis showed more cementum formation for both Retro MTA+ β-TCP (3.74 ± 0.34 mm) and Retro MTA group (3.24 ± 0.56 mm) compared to control group 1 (1. 15 ± 0.45 mm) and control group 2 (0.78 ± 0.65 mm). Formation of newly formed bone and cementum in the experimental groups were significantly higher as compared to the control groups (P < 0.0001).

Conclusions

Retro MTA or Retro MTA+ β-TCP covered with a collagen membrane resulted in regeneration of periodontal tissues. However, Retro MTA+ β-TCP showed tendency towards better results than the use of Retro MTA alone.

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.

Biomaterials, Current Strategies, and Novel Nano-Technological Approaches for Periodontal Regeneration

Periodontal diseases involve injuries to the supporting structures of the tooth and, if left untreated, can lead to the loss of the tooth. Regenerative periodontal therapies aim, ideally, at healing all the damaged periodontal tissues and represent a significant clinical and societal challenge for the current ageing population. This review provides a picture of the currently-used biomaterials for periodontal regeneration, including natural and synthetic polymers, bioceramics (e.g., calcium phosphates and bioactive glasses), and composites. Bioactive materials aim at promoting the regeneration of new healthy tissue. Polymers are often used as barrier materials in guided tissue regeneration strategies and are suitable both to exclude epithelial down-growth and to allow periodontal ligament and alveolar bone cells to repopulate the defect. The problems related to the barrier postoperative collapse can be solved by using a combination of polymeric membranes and grafting materials. Advantages and drawbacks associated with the incorporation of growth factors and nanomaterials in periodontal scaffolds are also discussed, along with the development of multifunctional and multilayer implants. Tissue-engineering strategies based on functionally-graded scaffolds are expected to play an ever-increasing role in the management of periodontal defects.

Early Wound Healing Score: a system to evaluate the early healing of periodontal soft tissue wounds

Purpose

Numerous indices have been proposed to analyse wound healing in oral soft tissues, but each has specific shortcomings. A new method of analysis, the Early Wound Healing Score (EHS), was evaluated in the present study. The aim was to assess more accurately early healing by primary intention of surgical incisions in periodontal soft tissues.

Methods

Twenty-one patients were treated with different surgical procedures comprising 1 or 2 vertical releasing incisions as part of a surgical access flap. Twenty-four hours after surgery, early wound healing at the vertical releasing incisions was assessed using the EHS. This score assessed clinical signs of re-epithelialization (CSR), clinical signs of haemostasis (CSH), and clinical signs of inflammation (CSI). Since complete wound epithelialization was the main outcome, the CSR score was weighted to be 60% of the total final score. Accordingly, a score of 0, 3, or 6 points was possible for the assessment of CSR, whereas scores of 0, 1, or 2 points were possible for CSH and CSI. Higher values indicated better healing. Accordingly, the score for ideal early wound healing was 10.

Results

Thirty vertical releasing incisions were assessed in 21 patients. At 24 hours after incision, 16 vertical releasing incisions (53.33%) received the maximum score of CSR, while 6 cases (20%) received an EHS of 10. None of the cases received 0 points.

Conclusion

The EHS system may be a useful tool for assessing early wound healing in periodontal soft tissue by primary intention after surgery.

Treatment of horizontal defect with and without platelet-rich fibrin matrix: A randomized comparative clinical study

AIM

The aim of the present study was to assess the clinical and radiographical parameters in horizontal bone defects in patients with chronic periodontitis.

MATERIALS AND METHODS

In this randomized, controlled clinical trial study, nine individuals with 94 sites having moderate to deep periodontitis were selected and distributed to Group A - open flap debridement (OFD), Group B - open flap debridement and intra marrow penetration (OFD + IMP) and Group C - Open flap debridement + Intramarrow penetration + platelet rich fibrin matrix (OFD + IMP + PRFM). Plaque index (PI) and gingival index (GI) were evaluated at baseline, 6 months, and 9 months after surgery. Probing pocket depth (PPD) and clinical attachment level (CAL) were recorded at baseline and 9 months after surgery. Radiographic assessment was carried out to measure the periodontal defect depth and defect fill percentage (DF%) at baseline and 9 months after the surgery using radiovisiography.

RESULTS

The statistical evaluation obtained after 9 months showed no significant difference between PI and GI at 9 months interval. Intergroup comparison of PPD and CAL has shown significant difference in Group C as compared to Group A and B with P < 0.05. The defect depth was statistically significant at 9 months in all the groups, and DF percentage (DF%) has shown statistically significant results in Group C as compared to A and B with P = of 0.001.

CONCLUSION

The addition of PRFM to horizontal type of periodontal defects has shown promising results over a 9-month follow-up period.

Effectiveness of adjunctive hyaluronic acid application in coronally advanced flap in Miller class I single gingival recession sites: a randomized controlled clinical trial

OBJECTIVES

The aim of this randomized controlled clinical trial was to evaluate the possible advantages of adjunctive hyaluronic acid (HA) application in the coronally advanced flap (CAF) procedure in single Miller class I/recession type 1 (RT1) gingival recession treatment.

MATERIAL AND METHODS

Thirty patients with one recession were enrolled; 15 were randomly assigned CAF + HA and 15 to CAF alone. The recession reduction (RecRed), clinical attachment level gain (CAL-gain), changes in probing pocket depth (PPD) and in the width of keratinized tissue (KT), complete root coverage (CRC), and mean root coverage (MRC) were calculated after 18 months. Post-operative morbidity (pain intensity, discomfort, and swelling) was recorded 7 days after treatment using visual analogue scale (VAS).

RESULTS

After 18 months, RecRed was statistically significantly higher in the test group (2.7 mm [1.0]) than in the control group (1.9 mm [1.0]; p = 0.007). PPD were found to be slightly but statistically significantly increased in both groups. No statistically significant difference was found for KT gain between treatments. CRC was 80% for test and 33.3% for control sites (p < 0.05). A MRC of 93.8 ± 13.0% for test and 73.1 ± 20.8% for control sites was calculated (p < 0.05). The test group reported lower swelling and discomfort values 7-days post-surgery (p < 0.05). Statistically significant difference was not found for pain intensity.

CONCLUSIONS

The adjunctive use of HA was effective in obtaining CRC for single Miller class I/RT1 gingival recession sites.

CLINICAL RELEVANCE

Adjunctive application of HA in the coronally advanced flap procedure may improve the reduction of the recessions and increase the probability of CRC in Miller class I recessions.

A Review of Evidence for a Therapeutic Application of Traditional Japanese Kampo Medicine for Oral Diseases/Disorders

Kampo medicines prescribed by specialized medical practitioners and Japanese physicians have gradually reemerged in Japan as alternatives to Western medications. Kampo formulations are composed of several plant extracts and, as such, the broad variety of phytochemicals they contain likely act synergistically to provide their beneficial effects. Kampo medicines have traditionally been prescribed for a number of health conditions, including chronic hepatitis, bronchial asthma, anemia, etc. The aim of this article is to review the beneficial effects of Kampos with respect to oral health. Pertinent papers published between 1970 and 2017 were retrieved by searching in PubMed, ScienceDirect, Web of Science, and Scopus using key words followed by evaluation of the relevant articles. In vitro studies have identified a number of properties that give credence to the potential of Kampos for treating or preventing oral diseases/disorders. Given their anti-microbial and anti-inflammatory properties, they may be promising agents for controlling periodontal diseases, oral mucositis, xerostomia, and drug-induced gingival overgrowth. Since some oral diseases have a complex etiology that involves microbial pathogens and the host immune response, agents with dual functionality such as Kampo phytochemicals may offer a therapeutic advantage.

Immunolocalization of connective tissue growth factor, transforming growth factor-beta1 and phosphorylated-SMAD2/3 during the postnatal tooth development and formation of junctional epithelium

Connective tissue growth factor (CTGF) is a downstream mediator of transforming growth factor-beta 1 (TGF-β₁) and TGF-β₁-induced CTGF expression is regulated through SMAD pathway. However, there is no literature showing the expression of TGF-β₁-SMAD2/3-CTGF signaling pathway during postnatal tooth development and the formation of junctional epithelium (JE). Hence, we aimed to analyze the localization of TGF-β₁, CTGF and phosphorylated SMAD2/3 (p-SMAD2/3) in the developing postnatal rat molars. Wistar rats were killed at postnatal (PN) 0.5, 3.5, 7, 14 and 21days and the upper jaws were processed for immunohistochemistry. At PN0.5 and PN3.5, weak staining for TGF-β₁ and CTGF was evident in preameloblasts (PA), while moderate to strong staining was seen in odontoblasts (OD), dental papilla (DPL), secretary ameloblasts (SA), preodontoblasts (PO) and polarized odontoblasts (PoO). There was no staining for p-SMAD2/3 in PA, SA, PO and PoO, although strong staining was localized in DPL. OD was initially moderately positive and then negative for p-SMAD2/3. At PN7, intense staining for TGF-β₁ and CTGF was observed in SA, OD, dental pulp (DP) and predentin respectively. p-SMAD2/3 was strongly expressed in DP and moderately expressed in SA and OD. At PN14 and PN21, both reduced enamel epithelium (REE) and JE showed a strong reaction for TGF-β₁ and CTGF. p-SMAD2/3 was intensely and weakly expressed in REE and JE respectively. These data demonstrate that the expression of CTGF, TGF-β₁ and p-SNAD2/3 is tissue-specific and stage-specific, and indicate a regulatory role for a TGF-β₁-SMAD2/3-CTGF signaling pathway in amelogenesis, dentinogenesis and formation of JE.

Root Conditioning with Citric Acid and Ethylenediaminetetraacetic Acid and their Effect on Fibrin Clot Adhesion to Dentin-A Scanning Electron Microscopic Study

INTRODUCTION

Root biomodifiers are used to remove the smear layer formed on the roots as a result of mechanical debridement and also to expose collagen fibers making the root surfaces biologically acceptable. Further, the blood element linkage to demineralized roots and clot stabilization by collagen fibres are vital for the wound healing and success of periodontal surgery.

AIM

The aim of this study was to evaluate and compare the distribution of fibrin network to dentin surfaces conditioned with citric acid and Ethylenediaminetetraacetic Acid (EDTA) using Scanning Electron Microscope (SEM).

MATERIALS AND METHODS

Thirty human dentin blocks (4 mm x 3 mm x 1 mm) were prepared and equally divided into three groups. The control Group A specimens were treated with Phosphate Buffered Saline (PBS). The study Group B and C specimens were treated with citric Acid and EDTA respectively. After conditioning, a drop of fresh human whole blood was placed on the dentin specimens and was allowed to clot. The specimens were then processed using standardized protocol for SEM. The dentin surfaces were then analysed for fibrin network linkage under SEM and scored according to the degree of fibrin linkage to the dentin surface. Statistical analysis was done using Kruskal Wallis test to compare the score values between the study groups. Pairwise comparison between the study groups was done using Mann Whitney U test with Bonferroni correction.

RESULTS

The fibrin network formed on the dentin network were analysed and scores were given. Kruskal Wallis test and Mann Whitney U test with Bonferroni correction were used for statistical analysis. It was found that most of the dentin specimens conditioned with citric acid and covered with human blood exhibited dense fibrin network compared to EDTA. However, statistical analysis showed that there were no significant differences found between the groups (p=0.35).

CONCLUSION

Citric acid and EDTA has almost comparable effect in promoting the adhesion of fibrin network onto the dentin surface which may further enhance connective tissue attachment to the root surface.

Scaffold requirements for periodontal regeneration with enamel matrix derivative proteins

Periodontitis affects the attachment of natural teeth, and infection or inflammation associated with periodontitis may affect peri-implant tissues. Enamel matrix derivative (EMD) proteins provide stimulation for self-regeneration of the damaged tissue when applied to wide intrabony defects as part of a mixture with bone graft material. As a first step of the process enhancing cell proliferation and ligament formation, we demonstrated that EMD protein precipitation depends strongly on the physical and chemical characteristics of the bone grafts used in the mixture. To guarantee optimum protein-stimulated self-regulation, the pH of the initial EMD formulation must therefore be adjusted between 3.9 and 4.2 in order to compensate the change in pH induced by the bone graft. Moreover, the interaction between the two components resulted in precipitates of different shape and size differently covering the grafts. This outcome might potentially have clinical implications on cell attachment and periodontal ligament extension, which deserve further in vitro and in vivo tests.

The influence of root surface distance to alveolar bone and periodontal ligament on periodontal wound healing

PURPOSE

The purpose of this animal study was to perform a 3-dimensional micro-computed tomography (micro-CT) analysis in order to investigate the influence of root surface distance to the alveolar bone and the periodontal ligament on periodontal wound healing after a guided tissue regeneration (GTR) procedure.

METHODS

Three adult Sus scrofa domesticus specimens were used. The study sample included 6 teeth, corresponding to 2 third mandibular incisors from each animal. After coronectomy, a circumferential bone defect was created in each tooth by means of calibrated piezoelectric inserts. The experimental defects had depths of 3 mm, 5 mm, 7 mm, 9 mm, and 11 mm, with a constant width of 2 mm. One tooth with no defect was used as a control. The defects were covered with a bioresorbable membrane and protected with a flap. After 6 months, the animals were euthanised and tissue blocks were harvested and preserved for micro-CT analysis.

RESULTS

New alveolar bone was consistently present in all experimental defects. Signs of root resorption were observed in all samples, with the extent of resorption directly correlated to the vertical extent of the defect; the medial third of the root was the most commonly affected area. Signs of ankylosis were recorded in the defects that were 3 mm and 7 mm in depth. Density and other indicators of bone quality decreased with increasing defect depth.

CONCLUSIONS

After a GTR procedure, the periodontal ligament and the alveolar bone appeared to compete in periodontal wound healing. Moreover, the observed decrease in bone quality indicators suggests that intrabony defects beyond a critical size cannot be regenerated. This finding may be relevant for the clinical application of periodontal regeneration, since it implies that GTR has a dimensional limit.