A comparative study of cyanoacrylate-based tissue adhesive and surgical sutures on marginal flap stability following coronally advanced flap.

INTRODUCTION: The present study evaluated the biomechanical characteristics of cyanoacrylate-based tissue adhesive (TA) compared to surgical sutures in coronally advanced flap (CAF) procedures using an ex-vivo model. MATERIAL AND METHODS: Thirty-six half-pig mandibles were divided into three groups, n=12 each: (I) CAF fixed with sutures (sling and tag suture technique), (II) CAF fixed with TA, and (III) CAF fixed with sutures and TA. At mandibular premolars, gingival recession defects extending 3 mm apical to the cemento-enamel junction (CEJ) were created. CAF procedures were performed using a split-full-split approach, with coronal advancement of the flap to 1 mm above the marked CEJ and stabilization according to the respective groups I-III. Marginal flap stability against pull-of forces (maximum tensile force) was measured with a universal material testing machine until the CEJ became visible. RESULTS: The comparison between groups I-III demonstrated a significantly increased maximum tensile force for the TA (II) compared to the suture group (I) (p<0.001). A significantly increased maximum tensile force was found for the suture and TA (III) compared to the suture group (I) (p<0.001). There was also a significantly increased maximum tensile force in the suture and TA (III) compared to the TA group (II) (p<0.001). CONCLUSION: The results suggest that cyanoacrylate-based TA can increase marginal flap stability compared to sutures in CAF procedures. CLINICAL RELEVANCE: Cyanoacrylate-based TA can be considered a useful and valuable adjunct to conventional suturing techniques in periodontal plastic surgery, especially in cases where high flap stability is required. The results of this ex-vivo study can only be transferred to the clinical situation with limitations. Clinical long-term follow-up data must be generated.

Orthodontic treatment in periodontally compromised patients: a systematic review.

OBJECTIVES: The aim of this systematic review was to examine the literature on aggressive and chronic periodontitis and orthodontics to clarify the therapy-relevant aspects of orthodontic treatment with altered biomechanics in periodontally compromised dentition. MATERIALS AND METHODS: Literature searches were conducted in the electronic databases "PubMed" and "DIMDI" using the keywords "aggressive periodontitis AND ortho*," "aggressive periodontitis AND orthodontics," "chronic periodontitis AND ortho*," and "chronic periodontitis AND orthodontics" for the publication period from January 1990 to July 2022. In addition, a manual search was carried out in the selected trade journals "Community Dental Health," "European Journal of Oral Sciences," and "Parodontologie." Human clinical trials were included, whereas animal experimental studies, case reports, and reviews were generally excluded. The appropriate studies were selected, and the relevant data was tabulated according to different parameters, regarding the study design, the study structure, and the conduct of the study. RESULTS: A total of 1067 articles were found in the preliminary electronic search. The manual search and review of all related bibliographies resulted in an additional 1591 hits. After the first screening, 43 articles were classified as potentially relevant and reviewed in their original form. After the suitability test, 5 studies with a total of 366 participants were included in the final evaluation. These included one randomized controlled trial and four low-evidence intervention studies. The studies were conducted in two university hospitals and three private practices. All participants underwent scaling and root plaining and periodontal surgery before the orthodontic treatment started. Mean probing pocket depth reduction before and after the interdisciplinary treatment was analyzed in all the included studies; mean difference in clinical attachment level in four of the studies was also included. All participants were enrolled in a continuous recall system. In all studies, orthodontic therapy in periodontally compromised patients improved function and esthetics, resulting in lower probing depths and clinical attachment gains. CONCLUSIONS: Orthodontic treatment can be used for patients with reduced periodontal support to stabilize clinical findings and improve function and esthetics. The prerequisite for this is a profound knowledge of altered biomechanics and an adapted interdisciplinary treatment approach. Due to the large heterogeneity of the included studies and their limited methodological quality, the results obtained in this review must be considered critically. Further randomized controlled long-term studies with comparable study designs are necessary to obtain reliable and reproducible treatment results. CLINICAL RELEVANCE: Patients with periodontal impairment can be successfully treated with orthodontics as part of interdisciplinary therapy. Orthodontic treatment has no negative impact on the periodontium; if minimal, controlled forces are used under non-inflammatory conditions.

Impact of Three Nonsurgical, Full-Mouth Periodontal Treatments on Total Bacterial Load and Selected Pathobionts.

For the treatment of periodontitis stage III/IV, a quadrant/week-wise debridement (Q-SRP) was compared with three full-mouth approaches: full-mouth scaling (FMS, accelerated Q-SRP within 24 h), full-mouth scaling with chlorhexidine-based disinfection (FMD), and FMD with adjuvant erythritol air polishing (FMDAP). The objective of this prospective, randomized study (a substudy of ClinicalTrials.gov, identifier: NCT03509233) was to compare the clinical and microbiological effects of the treatments. In total, 105 patients were randomized to one of the four aforementioned treatment groups, with n = 25, 28, 27, and 25 patients allocated to each group, respectively. At baseline and 3 and 6 months after treatment, the clinical parameters, including the pocket probing depths, clinical attachment level, and bleeding on probing, were recorded, and the prevalence of the total bacteria and four periodontal pathobionts (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia) was determined using real-time quantitative PCR. Concerning the clinical outcomes, all the treatment modalities were effective, but the full-mouth approaches, especially FMDAP, were slightly superior to Q-SRP. Using the FMD approach, the reduction in the bacterial load and the number of pathobionts was significantly greater than for FMS, followed by Q-SRP. FMDAP was the least effective protocol for microbial reduction. However, after a temporary increase 3 months after therapy using FMDAP, a significant decrease in the key pathogen, P. gingivalis, was observed. These findings were not consistent with the clinical results from the FMDAP group. In conclusion, the dynamics of bacterial colonization do not necessarily correlate with clinical outcomes after full-mouth treatments for periodontitis stage III/IV.

Biomechanical evaluation of cyanoacrylate-based tissue adhesive for intraoral wound closure.

OBJECTIVES: The aim of this study was to analyze the biomechanical characteristics of a novel cyanoacrylate-based tissue adhesive (CTA) for soft-tissue closure of the (non-) tooth-bearing alveolar process and around dental implants. MATERIALS AND METHODS: Halves of porcine mandibles (n = 21) were randomly divided into three experimental intraoral wound closure groups (A-C) with three different mucoperiosteal flap types (F1-3, n = 7 each): F1, crestal incision between the last incisor and the canine with a mesial and distal vestibular relief; F2, crestal double-T-shaped incision and dental implant placement between the canine and the first premolar; and F3, trapezoidal incision on the second premolar. F1-3 were respectively closed using (A) monofil non-resorbable sutures, (B) CTA, and (C) a combination of both. Tensile strength (TS) and elasticity (E) measurements were performed for biomechanical analysis. RESULTS: In F1, CTA showed a significantly reduced TS compared to A (p < 0.001) and C (p < 0.01). In F2, an increased TS of C compared to A (p < 0.01) and B (p < 0.001) was found. Here, E was significantly increased in C compared to B (p < 0.02). In F3, TS was significantly decreased in B compared to A (p < 0.01) and C (p < 0.001). The E in group C was significantly increased compared to B (p < 0.01). CONCLUSIONS: Different biomechanical characteristics between CTA and sutures were found. CTA could be a possible alternative to sutures for intraoral wound closure in special conditions. CLINICAL RELEVANCE: A combination of both, suturing and CTA, could be a promising option in critical soft-tissue wounds requiring high functional stability and elasticity.

Comparison of three full-mouth concepts for the non-surgical treatment of stage III and IV periodontitis: A randomized controlled trial.

AIM: To evaluate the clinical efficacy of full-mouth scaling (FMS), full-mouth disinfection (FMD), and FMD with adjuvant erythritol air-polishing (FMDAP) compared to quadrant-wise debridement (Q-SRP) in patients with periodontitis stage III/IV. METHODS: In this four-arm parallel, prospective, randomized, controlled multi-centre study, changes of pocket probing depths (PPDs), clinical attachment level (CAL), bleeding on probing (BOP), and proportion of closed pockets (PPD ≤4 mm without BOP) were evaluated at baseline and after 3 and 6 months. RESULTS: From 190 randomly participating patients, 172 were included in the final analysis. All groups showed significant (p < .05) improvements in all clinical parameters over 3 and 6 months. During the study period, FMDAP showed significantly higher reductions of mean PPD in teeth with moderate (PPD 4-6 mm) and deep (PPD > 6 mm) pockets and significantly increased proportions of pocket closure than Q-SRP. Patients treated with FMD had significantly greater PPD reduction in deep pockets and a higher percentage of pocket closure after 3 months but not after 6 months compared to Q-SRP. CAL and BOP changes did not significantly differ among all groups. Efficiency of treatment (time effort to gain one closed pocket) was significantly higher for FMDAP, FMD, and FMS compared to Q-SRP (6.3, 8.5, 9.5 vs. 17.8 min per closed pocket; p < .05). CONCLUSIONS: All treatment modalities were effective, without significant differences between full-mouth approaches. FMDAP showed improved clinical outcomes over Q-SRP for moderate and deep pockets after 6 months. Full-mouth protocols were more time-efficient than conventional Q-SRP. CLINICAL SIGNIFICANCE: The trial was registered in a clinical trial database (ClinicalTrials.gov: NCT03509233).

Treatment of Gingival Recession: When and How?

Gingival recession is a common finding in daily clinical practice. Several issues may be associated with the apical shift of the gingival margin such as dentine hypersensitivity, root caries, non-carious cervical lesions (NCCLs), and compromised aesthetics. The first step in an effective management and prevention program is to identify susceptibility factors and modifiable conditions associated with gingival recession. Non-surgical treatment options for gingival recession defects include establishment of optimal plaque control, removal of overhanging subgingival restorations, behaviour change interventions, and use of desensitising agents. In cases where a surgical approach is indicated, coronally advanced flap and tunnelling procedures combined with a connective tissue graft are considered the most predictable treatment options for single and multiple recession defects. If there is a contraindication for harvesting a connective tissue graft from the palate or the patient wants to avoid a donor site surgery, adjunctive use of acellular dermal matrices, collagen matrices, and/or enamel matrix derivatives can be a valuable treatment alternative. For gingival recession defects associated with NCCLs a combined restorative-surgical approach can provide favourable clinical outcomes. If a patient refuses a surgical intervention or there are other contraindications for an invasive approach, gingival conditions should be maintained with preventive measures. This paper gives a concise review on when and how to treat gingival recession defects.

Flapless application of enamel matrix derivative in periodontal retreatment: A multicentre randomized feasibility trial.

AIM: To investigate the potential benefit of enamel matrix derivative (EMD) as adjunct to re-instrumentation of residual pockets persisting after steps 1 and 2 of periodontal therapy. MATERIAL AND METHODS: 44 adult patients participated in a multicentre feasibility randomized clinical trial with split-mouth design. They had presented at re-evaluation after initial non-surgical periodontal therapy (steps 1 and 2 of periodontal therapy) for generalized periodontitis with at least 2 teeth with residual probing pocket depths (PPD) ≥5 and ≤8 mm, with bleeding on probing (BOP). Two teeth with similar PPD were randomized to receive re-instrumentation either with (test) or without (control) adjunctive flapless administration of EMD. Differences in the changes of PPD and BOP from baseline to 6 and 12 months were analysed, and the frequencies of pocket closure (PPD ≤4 mm and no BOP) compared. RESULTS: For the primary outcome "change of mean PPD after 6 months," a significant additional benefit of 0.79 ± 1.3 mm (p < .0001) could be observed for the test group. At 12 months, this difference could be maintained (0.85 ± 1.1 mm; p < .0001). The frequency of pocket closure in the test group was 69% at 6 and 80% at 12 months and significantly higher than in the control group with 34% and 42%, respectively (p < .01). CONCLUSIONS: The results of the present feasibility study indicate a benefit of adjunctive EMD during non-surgical retreatment (step 3 of periodontal therapy) of residual deep pockets.

Effects of adjunctive light-activated disinfection and probiotics on clinical and microbiological parameters in periodontal treatment: a randomized, controlled, clinical pilot study.

OBJECTIVES: The aim of this pilot study was to evaluate the clinical and microbiological outcomes of light-activated disinfection (LAD) alone or combined with probiotics as an adjunct to non-surgical periodontal treatment. MATERIALS AND METHODS: In this single-blinded, randomized, controlled clinical pilot study, 48 patients (28 females and 20 males) with untreated periodontitis (stages II and III, grade B) were included. Using a parallel-group design, patients were randomly assigned into 3 groups to receive subgingival debridement (SD) alone (group 1, n = 16), SD with LAD (group 2, n = 16), or SD with LAD plus probiotic treatment (group 3, n = 16). Probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), gingiva-index simplified (GIs), plaque-control record (PCR), and subgingival microbiological samples were analyzed at baseline, 3 months, and 6 months of follow-up. RESULTS: All treatment modalities demonstrated clinical improvements in PPD and CAL at 6 months compared to baseline but without a statistical significant difference between the groups. The combination of SD + LAD + probiotic treatment (group 3) demonstrated significantly greater reductions in BOP, GIs, and red complex bacteria P. gingivalis and T. forsythia compared with other groups at 6 months (p < 0.05). CONCLUSIONS: A single application of LAD as an adjunct to SD provided no additional clinical and microbiological benefits compared to SD alone. The combination of SD + LAD + probiotic treatment in group 3 led to further improvements of the inflammatory parameters. CLINICAL RELEVANCE: The additional use of probiotics in periodontal treatment can be a useful approach to support inflammation and infection control of periodontal tissues. Further studies are necessary to determine the extent of added benefit for this treatment approach.

Application of enamel matrix derivative in conjunction with non-surgical therapy for treatment of moderate to severe periodontitis: A 12-month, randomized prospective, multicenter study.

BACKGROUND: Treatment of periodontitis aims to halt progressive bone and attachment loss and regenerate periodontal structures. In this study, the effect of using an enamel matrix derivative (EMD) as an adjunct to non-surgical periodontal therapy (test) versus non-surgical therapy alone (control) was evaluated. METHODS: A prospective, split-mouth, multicenter study evaluated scaling and root planing (SRP) with and without EMD in 51 patients presenting with moderate to severe periodontitis (PPD = 5 to 8 mm) in at least 2 pockets per contralateral quadrants within the same arch. The primary outcome variable was change in clinical attachment level (CAL) after 12 months. Secondary variables included probing pocket depth (PPD), bleeding on probing (BoP), gingival margin level, dentin hypersensitivity, and percent of pockets converted to sites no longer requiring surgical treatment. RESULTS: CAL changed significantly (P  < 0.001) from baseline to 12 months for both treatment modalities (test = -2.2 ± 1.5 mm versus control = -2.1 ± 1.3 mm) and similarly for PPD; the difference between groups was not significant. A significant difference, favoring test conditions, was observed in percentage of both healthy PPDs (pockets < 5 mm) and converted pockets (sites no longer requiring surgical treatment); 79.8% of test versus 65.9% of control sites. BoP decreased significantly more (P < 0.05) in test sites (BoP at 17.8% test versus 23.1% control). CONCLUSIONS: Both test and control treatments resulted in significant improvements in CAL and PPD. The adjunct use of EMD with SRP resulted in significantly greater improvements in overall periodontal health with less frequent BoP and a higher number of healthy PPDs.

The reproducibility of electronic color measurements of the marginal gingiva.

INTRODUCTION: This study evaluated the reproducibility of electronic color determination system evaluations of the marginal gingiva, which could be important for adhesive cervical fillings or prosthetic restorations that imitate the gingiva. MATERIAL AND METHODS: In 50 subjects, the L*, a*, and b* color coordinates were evaluated five times at a point in the marginal area of a central incisor using different electronic color determination systems: (SP) Shadepilot, (ES) Easyshade, (CE) Crystaleye, and (SV) X-Rite. The mean color difference (ΔE) and its standard deviation between the five measurements from each participant were calculated separately for each device. Further ICC for interdevice reliability was determined. RESULTS: The L*, a*, and b* color coordinates and ΔE values differed significantly among the systems (p < 0.001). Within each patient and measurement system, ΔE ranged from 1.4 to 3.2 (SD 1.1-2.5), L* from 2.6 to 5.7 (SD 2.6-5.7), a* from 11.9 to 21.3 (SD 3.6-3.9), and b* from 15.1 to 28.9 (SD 1.7-4.3). Interdevice reliability ranged between 0.675 and 0.807. CONCLUSIONS: Color determination of the marginal gingiva using the electronic tooth color determination systems tested herein showed limited reproducibility. The results obtained with the different measurement systems differed enormously. CLINICAL RELEVANCE: These results show that the electronic color measurement devices tested allow no high reproducible determination of color coordinates of the marginal gingiva.

A Comparison of Clinical and Radiological Parameters in the Evaluation of Molar Furcation Involvement in Periodontitis.

Objective: The aim of this study was to compare clinical, intra-surgical, 2D (panoramic) and 3D (CBCT)-based parameters in assessing molar furcation involvement (FI). Materials and Methods: Six patients with generalized periodontitis Stage II to IV, Grade B and C who were scheduled for the periodontal flap surgical treatment were recruited in the study. In total, 38 molar teeth with 93 furcation sites were analysed. All subjects had comprehensive periodontal examination, which included an assessment of molar FI using Naber's probe according to modified Glickman's classification. Periodontal surgery was performed in patients with at least one maxillary molar with probing depth of ≥6 mm. This probing demonstrated lower grade of FI compared with intra-surgical findings. Results: Periodontal probing, intra-surgical measurement and measurements based on CBCT significantly correlated with each other regarding the assessment of FI, with r values ranging between 0.81 to 1.00 (p<0.01). The correlation of panoramic radiograph with periodontal probing is 0.49, with CBCT 0.39 and with intra-surgical measurements 0.36. The results showed an excellent agreement and higher accuracy between intra-surgical measurements and CBCT (0.96), in contrast to clinical examination and panoramic radiography- 0.87 and 0.63 respectively. Different clinical and radiological modalities showed a correlation among each other. They are accurate and have their own benefits, which makes (renders) them useful in establishing periodontal diagnosis and treatment planning. Conclusion: However, CBCT offers significant advantages including excellent agreement and higher accuracy and can be used as justified as excellent diagnostic tool in detecting and locating FI to provide a more reliable diagnosis and basis for treatment decisions.

Correction to: human periodontal ligament fibroblasts stimulated by nanocrystalline hydroxyapatite paste or enamel matrix derivative. An in vitro assessment of PDL attachment, migration, and proliferation.

In the original published version of this article, the middle name for author Mirko H. H. Schmidt is missing.

Changes in anatomic position of root canal orifices in pluriradicular teeth following re-location during endodontic treatment.

Direct access to the root canals in posterior teeth for endodontic treatment is most frequently facilitated by the straightening of the coronal parts of the root canals, having as a consequence the relocation of the canal orifices on the map of the floor of the pulp chamber (Christie and Thompson, 1994). This procedure intentionally moves the coronal aspect of a canal away from the center of the chamber, while simultaneously removing internal dentin from the pulp chamber walls. The aim of this study was to evaluate the displacement resulting from the relocation of root canal orifices during the initial phase of rotary root canal treatment in molars using the dental operating microscope (DOM) and digital image processing. Forty-three molars (17 maxillary and 26 mandibular) belonging to 43 patients (aged 18-62 years) with indications for root canal treatment were endodontically treated. The differences between the initial perimeter and the perimeter of the root canal orifices polygon after relocation varied between 2.7 and 3.4µm (mean 3.0µm), while the differences between the initial area and the area after relocation varied between 2,448,456.8 and 3,249,306.6µm2 (mean 2,848,881.7). The increase in access to the cavities and the alterations of the pulp chambers can be satisfactorily approximated by the variations of the perimeters and areas of the pulp floor polygons during root canal treatment. From a clinical perspective, these results indicate that there is a significant decrease in tooth substance in molars (except MB2).

Biofunctionalization of porcine-derived collagen matrix using enamel matrix derivative and platelet-rich fibrin: influence on mature endothelial cell characteristics in vitro.

OBJECTIVES: The present study evaluated the effect of an enamel matrix derivative (EMD) and platelet-rich fibrin (PRF)-modified porcine-derived collagen matrix (PDCM) on human umbilical vein endothelial cells (HUVEC) in vitro. MATERIALS AND METHODS: PDCM (mucoderm®) was prepared to 6 mm (±0.1 mm) diameter discs. PDCM samples were incubated with either EMD, PRF, or control solutions for 100 min at 4 °C before the experiments. Cell-inducing properties of test materials on HUVEC cells were tested with cell proliferation assays (MTT, PrestoBlue®), a cytotoxicity assay (ToxiLight®), a Boyden chamber migration assay, and a cell attachment assay. Scanning electron microscopy (SEM) imaging was performed to determine the surface and the architecture of the modified matrices. RESULTS: Cell proliferation was elevated in the EMD and PRF groups compared with control (p each ≤0.046). PRF modification increased HUVEC migration ability by 8-fold compared with both control and EMD groups (p each <0.001). Both treatments significantly promoted the cell attachment of HUVEC to PDCM, as assessed by direct cell counts on the matrices (p each <0.001). CONCLUSIONS: HUVEC cell characteristics were overall improved by EMD- and PRF- modified PDCM. Adsorbed bioactive molecules to the PDCM surface may have contributed to a more preferable environment to surrounding cells. CLINICAL RELEVANCE: The results may give evidence that PDCM modification with EMD or PRF, respectively, might be a useful approach to improve clinical outcomes, to prevent inflammatory reactions and wound-healing disturbances, and to expand the clinical application area of PDCM.

New insights into the cellular makeup and progenitor potential of palatal connective tissues.

The present study investigated the regenerative potential of connective tissues harvested from two palatal areas widely used as donor sites for muco-gingival surgical approaches. Connective tissue grafts (CTGs) were obtained by de-epithelialisation of a free gingival graft (deCTG) and by a split flap approach from a previous donor site (reCTG). Two types of mesenchymal stem cell (MSCs) were isolated and were named de-epithelialised MSCs (deMSCs) and re-entry MSCs (reMSCs). The cells were characterised and cellular functionality was investigated. CTGs were evaluated using immunohistochemical and ultrastructural approaches. No significant differences were observed regarding the frequency of colony-forming unit- fibroblasts, migration potential, and population doubling time between the two cell lines (p > 0.05). Both cell lines showed positivity for CD105, CD73, CD90, and CD44 and negative expression for CD34/45, CD14, CD79a, and HLA-DR. MSCs from both cell lines successfully differentiated into osteogenic, adipogenic, and chondrogenic lineages. Cells expressing antigens characteristic of CD34+ stromal cells (CD34+, αSMA-, CD31-) were traced in both CTGs. Ultrastructural analysis highlighted the presence of putative progenitors, namely fibroblasts,-in the pericapillary regions and in remote regions of the lamina propria- and pericytes-surrounding the capillaries. This study provides supplementary arguments for the use of CTG grafts in clinical practice due to the presence of putative progenitor cell. However, results were inconclusive regarding clinical decision-making to determine optimal harvesting area. Prior harvesting in the donor area did not appear to alter the regenerative capabilities of the connective tissue.

Histology and surface ultrastructure during early healing after gingival augmentation with a three-dimensional collagen matrix: A report of six cases.

OBJECTIVES: The objective of the present case series is to describe the histology and surface ultrastructure of augmented keratinized gingival mucosa in humans during the early healing phase after surgical placement of a xenogeneic collagen matrix. METHOD AND MATERIALS: Six patients underwent surgical augmentation of keratinized tissue by placement of a three-dimensional (3D) xenogeneic collagen matrix. Full-depth mucosal biopsies including original attached gingiva, augmented gingiva, and the separation zone were performed at baseline and at postoperative days 7 and 14. The specimens were stained with hematoxylin-eosin, Masson-trichrome, picrosirius red, and Papanicolaou's trichrome. Low-vacuum scanning electron microscopy (SEM) surface analysis was correlated with histology. RESULTS: The separation zone was clearly visible upon histologic and SEM examination at 7 days. The portions of augmented mucosa consisted of well-structured, immature gingival tissue with characteristics of per secundam healing underlying a completely detached amorphous collagenous membrane-like structure of approximately 100 µm thick. At 14 days, histologic and ultrastructural examinations showed an almost complete maturation process. There were no detectable remnants of the collagen matrix within the newly formed tissues at either time point. CONCLUSIONS: Within their limits the results suggest that the 3D collagen matrix appears to play an indirect role during the early phase of wound healing by protecting the newly formed underlying tissue and guiding the epithelialization process.

Gingival recession coverage: Do we still need autogenous grafts?

A variety of periodontal plastic surgical techniques have been proposed to obtain root coverage of gingival recession defects. All of the available root coverage procedures are able to provide significant root coverage for Miller Class I and II recession-type defects. However, only the subepithelial connective tissue graft in conjunction with a coronally advanced flap appears consistently effective across all clinical parameters, and is therefore currently considered the gold standard for gingival recession therapy. The major shortcomings of connective tissue graft procedures include patient morbidity associated with the second surgical site and limited availability of palatal donor tissue. More recently, 3D collagen matrices of human and porcine origin have been introduced as possible alternatives to autogenous connective tissue grafts in recession coverage procedures. This paper aims to give an overview on the possible use of collagen matrices as soft tissue substitutes and a possible alternative to connective tissue grafts in the surgical treatment of gingival recession defects.

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.

Influence of porcine-derived collagen matrix on endothelial progenitor cells: an in vitro study.

Porcine-derived collagen matrix (PDCM) has been reported as a promising alternative to autogenous soft tissue grafts in periodontal plastic surgery. The aim of this study was to analyze the influence of a novel PDCM on endothelial progenitor cells (EPC) in vitro. EPC were isolated from human peripheral blood, cultured and transferred on the PDCM (mucoderm®). Tissue culture polystyrene surface (TCPS) served as control. Cell viability of EPC on PDCM was measured by a MTT and PrestoBlue® assay. Migration ability was tested using a Boyden migration assay. A ToxiLight® assay was performed to analyze the influence of PDCM on adenylate kinase (ADK) release and apoptosis rate of EPC. Using the MTT assay, EPC cultured on PDCM demonstrated a significantly increased cell viability compared to the control group at days 3, 6 and 12 (p each <0.001). According to the PrestoBlue® assay, EPC showed a significant increase of cell viability compared to the control group at 48, 72, and 96 h (p each <0.001). In the Boyden migration assay, a significantly increased EPC migration ability could be observed after 3-12 days (p each ≤0.001). No significantly increased apoptosis rate of EPC on PDCM could be observed with exception after 96 h (p each >0.05). Overall, our results suggest a good biocompatibility of PDCM without any cytotoxic effects on EPC, which might support a rapid revascularization and therefore a sufficient ingrowth of the PDCM.