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Guided bone regeneration is frequently used to reconstruct the alveolar bone to rehabilitate the mastication using dental implants. The purpose of this article is to research the properties of eggshell membrane (ESM) and its potential application in tissue engineering. The study focuses on the structural, mechanical, and histological characteristics of ESM extracted from Gallus domesticus eggs and to compare them to a commercially available porcine pericardium membrane (Jason® membrane, botiss biomaterials GmbH, Zossen, Germany). Thus, histology was performed on the ESM, and a comparison of the microstructure through scanning electron microscopy and atomic force microscopy (AFM) was conducted. Also, mechanical tensile strength was evaluated. Samples of ESM were prepared and treated with alcohol for fixation and disinfection. Histological analysis revealed that the ESM architecture is constituted out of loose collagen fibers. However, due to the random arrangement of collagen fibers within the membrane, it might not be an effective barrier and occlusive barrier. Comparative analyses were performed between the ESM and the AFM examinations and demonstrated differences in the surface topography and mechanical properties between the two membranes. The ESM exhibited rougher surfaces and weaker mechanical cohesion attributed to its glycoprotein content. The study concludes that while the ESM displays favorable biocompatibility and resorb ability, its non-uniform collagen arrangement limits its suitability as a guided bone regeneration membrane in the current non-crosslinked native form. Crosslinking techniques may enhance its properties for such applications. Further research is needed to explore modifications and processing methods that could leverage the ESM's unique properties for tissue engineering purposes. [ABSTRACT FROM AUTHOR]

Aim: To assess the long‐term stability of attachment gain in infrabony defects (IBDs) 10 years after regenerative treatment with an enamel matrix derivative (EMD) alone. Materials and Methods: Two centres (Frankfurt [F] and Heidelberg [HD]) invited patients for re‐examination 120 ± 12 months after regenerative therapy. Re‐examination included clinical examination (periodontal probing depths (PPD), vertical clinical attachment level (CAL), plaque index (PlI), gingival index (GI), plaque control record, gingival bleeding index and periodontal risk assessment) and review of patient charts (number of supportive periodontal care [SPC] visits). Results: Both centres included 52 patients (29 female; median baseline age: 52.0 years; lower/upper quartile: 45.0/58.8 years; eight smokers), each contributing one IBD. Nine teeth were lost. For the remaining 43 teeth, regenerative therapy showed significant CAL gain after 1 year (3.0; 2.0/4.4 mm; p <.001) and 10 years (3.0; 1.5/4.1 mm; p <.001) during which CAL remained stable (−0.5; −1.0/1.0 mm; p = 1.000) after an average SPC of 9 years. Mixed‐model regression analyses revealed a positive association of CAL gain from 1 to 10 years with CAL 12 months post operation (logistic: p =.01) as well as a higher probability for CAL loss with an increasing vertical extent of a three‐walled defect component (linear: p =.008). Cox proportional hazard analysis showed a positive association between PlI after 12 months and tooth loss (p =.046). Conclusion: Regenerative therapy of IBDs showed stable results over 9 years. CAL gain is associated with CAL after 12 months and decreasing initial defect depth in a three‐walled defect morphology. Tooth loss is associated with PlI 12 months post operation. Clinical trial number: DRKS00021148 (URL: https://drks.de). [ABSTRACT FROM AUTHOR]

The aim of this investigation was to evaluate a new resorbable, monolayer, noncross-linked collagen barrier membrane for immobilizing bone augmentation material during horizontal guided bone regeneration (GBR) procedures. GBR was performed on 36 consecutive patients in 49 sites, with 103 implants placed either simultaneously or after a healing period. Healing time, suture retention, postoperative complications, and functional outcome after GBR, implant placement, and prosthesis loading were assessed. A wound dehiscence rate of only 12% and a graft failure rate of 4% occurred. Mean healing time was 5.8 months for simultaneous placement and 7.9 + 4.8 months for two-stage procedures. The implant survival rate was 100% after a mean follow-up of 18.3 months from implantation. These early data demonstrate a low dehiscence rate and excellent potential of this new noncross-linked collagen membrane for use with horizontal ridge augmentation. [ABSTRACT FROM AUTHOR]

Aim This study investigated the periodontal regenerative potential of gingival margin-derived stem/progenitor cells ( G- MSCs) in conjunction with IL-1ra-releasing hyaluronic acid synthetic extracellular matrix ( HA-s ECM). Materials and Methods Periodontal defects were induced at four sites in eight miniature pigs in the premolar/molar area (−4 weeks). Autologus G- MSCs were isolated from the free gingival margin and magnetically sorted, using anti- STRO-1 antibodies. Colony formation and multilineage differentiation potential were tested. The G- MSCs were expanded and incorporated into IL-1ra-loaded/unloaded HA-s ECM. Within every miniature pig, four periodontal defects were randomly treated with IL-1ra/ G- MSCs/ HA-s ECM (test group), G- MSCs/ HA-s ECM (positive-control), scaling and root planing ( SRP; negative control-1) or left untreated (no-treatment group; negative control 2). Differences in clinical attachment level (Δ CAL), probing depth (Δ PD), gingival recession (Δ GR), radiographic defect volume (Δ RDV), and changes in bleeding on probing ( BOP) between baseline and 16 weeks post-transplantation, as well as periodontal attachment level ( PAL), junctional epithelium length ( JE), connective tissue adhesion ( CTA), cementum regeneration ( CR) and bone regeneration ( BR) at 16 weeks post-transplantation were evaluated. Results Isolated G- MSCs showed stem/progenitor cell characteristics. IL-1ra loaded and unloaded G- MSCs/ HA-s ECM showed higher Δ CAL, Δ PD, Δ GR, PAL, CR and BR as well as a lower JE compared to their negative controls and improved BOP. Conclusion G- MSCs in conjunction with IL-1ra-loaded/unloaded HA-s ECM show a significant periodontal regenerative potential. [ABSTRACT FROM AUTHOR]

Background and Objective Recently, porcine acellular dermal matrix ( PADM) has been proposed as a possible alternative to autogenous grafts in periodontal plastic surgery. The aim of the present study was to investigate the in vitro responses of four different oral cell lines cultured on a novel PADM. Furthermore, tissue reaction to PADM was evaluated histologically after subcutaneous implantation in mice. Material and Methods Human gingival fibroblasts ( HGF), human osteoblast-like cells, human umbilical vein endothelial cells and human oral keratinocytes ( HOK) were cultured and transferred on to the PADM. A tissue culture polystyrene surface served as the control. The viability of all tested cell lines on PADM was measured by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide colorimetric assay and PrestoBlue® reagent. The ToxiLight® assay was performed to analyze the effect of PADM on adenylate kinase release. PADM was implanted into nude mice subcutaneously and subjected to histological analysis after 21 d. Results Using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide colorimetric assays, all tested cell lines cultured on PADM demonstrated a significant increase of viability compared to the control group (each p < 0.001) with the exception of HGF and HOK after 3 d (each p > 0.05). According to the PrestoBlue® analysis, all cell lines demonstrated a significant increase of viability compared to the control group at the particular points of measurement after 18 h ( HGF p < 0.01; human osteoblast-like cells, human umbilical vein endothelial cells, HOK each p < 0.001). No significant cytotoxic effects of PADM on the tested cell lines could be observed, as assessed by changes in adenylate kinase release. Subcutaneous implantation of PADM into nude mice demonstrated good integration with surrounding tissues and significant revascularization of its collagen structure. Conclusion Overall, the results suggest that PADM is a promising substitute for autogenous soft tissue grafts in periodontal surgery. [ABSTRACT FROM AUTHOR]

Objectives To investigate the impact of two surface decontamination methods on the long-term outcomes following combined surgical resective/regenerative therapy of advanced peri-implantitis lesions. Material and Methods Seventeen patients ( n = 17 combined supra- and intrabony-defects) completed the 48 months follow-up observation following access flap surgery, granulation tissue removal and implantoplasty at bucally and supracrestally exposed implant parts. The remaining unmodified implant surface areas were randomly treated using either (i) an Er: YAG laser ( ERL), or (ii) plastic curets + cotton pellets + sterile saline ( CPS), and augmented with a natural bone mineral + collagen membrane. Results At 48 months, CPS-treated sites tended to reveal higher reductions in mean BOP ( CPS: 85.2 ± 16.4% versus ERL: 71.6 ± 24.9%) and CAL values ( CPS: 1.5 ± 2.0 mm versus ERL: 1.2 ± 2.0 mm) when compared with the ERL group. In both groups, clinical outcomes were not directly influenced by the initial defect configuration. Conclusion The 4-year clinical outcomes obtained following combined surgical resective/regenerative therapy of advanced peri-implantitis were not influenced by the method of surface decontamination. [ABSTRACT FROM AUTHOR]

Objectives To investigate the influence of autogenous platelet concentrate ( APC) on the long-term regeneration outcome 7 years after guided tissue regeneration ( GTR) in deep intrabony periodontal defects. Material and Methods In 25 patients, two deep contra-lateral intrabony defects were treated according to GTR (randomized split-mouth-design). In the test defects, APC was additionally applied. After 7 years, healing results were assessed clinically by a blinded examiner and compared to baseline and 12-months results. Furthermore, a tooth survival analysis was performed. Results After 7 years, 23 patients were available for survival analysis and 16 patients for split-mouth analysis; 84% of the test and control teeth were still in situ. In both groups, the median attachment level of 10.5 mm [(25/75%): test 9.0/13.0, control 10.0/12.0] at baseline was significantly ( p ≤ 0.05) reduced to 6.0 mm [test 4.0/6.8, control 5.0/7.0] after 1 year. Six years later, it had increased again to 7.0 mm in test sites [5.3/10.0] ( p ≤ 0.05) and had remained stable in control sites [5.0/7.8] ( p > 0.05). Bleeding on Probing ( BOP) had increased in both groups. During the last 6 years, only 26% of the patients received a structured supportive periodontal therapy in the clinic. Conclusion Within its limitations, the present study indicates that the clinical outcome of GTR therapy can be maintained over 7 years. However, the additional use of APC may even have a possibly negative influence on the long-term stability. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the prevalence and distribution of root caries in the adult population of Pomerania, Germany. The study sample comprised 6,267 randomly selected subjects who were scheduled for examination from 1997 to 2001 (population-based cross-sectional study, response rate: 69%, age range 20-79 years). 499 edentulous persons were excluded from the dental examination (12%) performed according to WHO guidelines (1997). In the statistical analysis, frequency distributions, means and median values were calculated and subdivided for different age groups. The percentage of exposed and affected root surfaces increased with age (root caries index 4.6-10.6%). The mean number of carious/ filled root surfaces (RDFS) rose from 0.4 per person (25-34 years) to 2.3 (55-64 years) and dropped for seniors due to the low number of retained teeth. Fillings comprised the largest proportion of the RDFS (69.5%). Most caries/fillings were found on buccal surfaces, the highest rate in mandibular premolars. With about half of over-45-year-olds having at least one carious/filled root surface and increasing number of retained teeth in seniors, root caries is a relevant and probably growing disease in Pomerania and East Germany. [ABSTRACT FROM AUTHOR]

Background: The aim of the present study was to evaluate defect width and two different definitions of defect depth as prognostic factors of periodontal healing in infrabony defects treated by regenerative therapy 6 and 24 months after surgery. Methods: In 32 patients with moderate to advanced periodontitis, 50 infrabony defects were treated by the guided tissue regeneration (GTR) technique using non-resorbable or bioabsorbable barriers. Clinical parameters were assessed, and 50 triplets of standardized radiographs were taken before surgery and 6 and 24 months after surgery. Using a computer-assisted analysis, the distances cemento-enamel junction (CEJ) to alveolar crest (AC), CEJ to bony defect (BD), horizontal projection of the most coronal extension of the bony wall to the root surface to BD, width, and angle of the bony defects were measured. Depth of the bony defect was 1) calculated as CEJ-BD minus CEJ-AC (INFRA1) and 2) measured as horizontal projection of the most coronal extension of the bony wall to the root surface to BD (INFRA2). Results: Whereas statistically significant vertical clinical attachment level gains (CAL-V: 3.36 +/- 1.59 mm/ 3.41 +/- 1.72 mm; P < 0.001) could be found both 6 and 24 months after surgery, bony fill (0.70 +/- 2.52 mm; P = 0.056/1.21 +/- 2.55 mm; P < 0.005) was significant 24 months post-surgically only. In a multilevel regression analysis, CAL-V gain was predicted by bioabsorbable membrane (P = 0.005), baseline probing depths (PD) (P < 0.001), and actual smoking (P < 0.05). Bony fill could be predicted by baseline depth of the infrabony component as determined by INFRA2 (P < 0.05), angulation of bony defect (P < 0.005), and gingival index at baseline (P < 0.001). In narrow (< 37 degrees) and deep (> or = 4 mm) infrabony defects, bony fill was more pronounced than in wide and shallow defects (P < 0.001). Conclusions: Improvement achieved by GTR in infrabony defects can be maintained up to 24 months after surgery. Narrow and deep infrabony defects respond radiographically and are to some extent clinically more favorable to GTR therapy than are wide and shallow defects. The infrabony component of bony defects, as determined by the distance from the most coronal extension of the lateral bony wall to BD (INFRA2), is a better predictor of bony fill than that determined by AC-BD (INFRA1). [ABSTRACT FROM AUTHOR]

Background: Advanced peri-implant intrabony defects require comprehensive surgical treatment regimens different from periodontal therapy strategies. The purpose of this longitudinal trial was to evaluate the peri-implant outcomes following guided bone regeneration with 3 treatment protocols. Methods: In 25 patients, 41 peri-implant defects with supporting bone loss >50% of the implant length were treated with flap surgery plus autogenous bone grafts alone (FG) (controls, n = 12) plus non-resorbable (FGM) (test 1, n = 20) or bioabsorbable barriers (FGRM) (test 2, n = 9) and supportive antimicrobial therapy. Following submerged healing, the membranes were removed (FGM), and the peri-implant probing depths (PD), probing bone levels (BL), mobility scores (PT), and intrabony defect height (DH) were radiographically evaluated at baseline, 6 months, and 1 and 3 years post-therapy. Results: Non-surgical/anti-infective therapy resulted in a limited improvement of PD scores after 6 months. At the 3-year visit, surgical treatment revealed significant changes from baseline for the controls and both of the test groups for PD: 5.1 +/- 2.7 mm (FG), 5.4 +/- 3.0 mm (FGM), and 2.6 +/- 1.6 mm (FGRM), and for BL: 3.2 +/- 2.4 mm (FG), 3.4 +/- 2.4 mm (FGM), and 2.3 +/- 1.6 mm (FGRM), Mann-Whitney test, P < or = 0.05. The changes for DH and PT were significant only for FG- and FGM-treated subjects. The overall improvement for FGRM-treated patients during the 3-year observation was less marked. However, the differences between the 3 surgical treatment protocols did not affect the treatment outcomes after 3 years. Conclusions: Autogenous bone grafting is an appropriate treatment regimen to augment open crater-formed peri-implant defects. Although certain clinical situations require an additional fixation of barrier membranes, their routine application should be approached with caution. [ABSTRACT FROM AUTHOR]

Background/aim: With the demographic change and associated chronic bone loss, the need for cytocompatible bone replacement materials arise in modern medicine. The aim of this in vitro study was to investigate the cytocompatibility of eleven different bone substitute materials and membranes., Materials and Methods: Seven bone substitute materials and four membranes were assessed in vitro. The specimens were tested based on their interaction with MC3T3 pre-osteoblasts, through the utilization of viability, proliferation, and cytotoxicity assays. Cell vitality was evaluated using live-dead staining., Results: Although we found minor differences in cytocompatibility among the assessed materials, all tested materials can be considered as cytocompatible with a viability of more than 70% of the negative control, which indicates the non-toxic range as defined in current, international standards (DIN EN ISO 10993-5:2009, German Institute for Standardization, Berlin, Germany). Direct live-dead staining assays confirmed satisfactory cytocompatibility of all tested membranes., Conclusion: All examined bone substitute materials and membranes were found to be cytocompatible. In order to assess whether the observed minor differences can impact regenerative processes, further in vivo studies need to be conducted., (Copyright © 2021 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

The author reflects on the status of periodontics profession. He states that the number of periodontics specialists will decline in the near future and younger clients will be more inclined to place fancy implants than attempt to retain natural teeth. He cites that about one million implants have been placed in Germany in 2007.

Septic segmental bone voids of the diaphysis are difficult to manage. The induced membrane technique by Masquelet has been successfully used to reconstruct segmental defects more than 20 cm. Our article describes a series of 13 cases with extensive posttraumatic bone loss of the metatarsal, tibial, femoral and radial bones after septic injuries followed by multiple surgical interventions. Antibiotic-impregnated polymethyl methacrylate (PMMA) cement spacers were implanted after successful eradication of bacterial infections of soft tissue and bones. After a mean of 9.8 weeks, body-induced membranes were established and the cements spacers removed. To fill up the bone void, cancellous bone autografts were implanted into the membranes. The follow-up examination after 24 months revealed bony union in all cases and favorable functional results. The induced membrane technique has shown to be effective in treating bone defects of upper and lower extremity bone defects. [ABSTRACT FROM AUTHOR]

Background: New cell-based treatments for articular cartilage repair are needed. As the optimal scaffold for cartilage repair has yet to be developed, scaffold-free cartilage implants may remove the complications caused by suboptimal scaffolds., Hypothesis: The implantation of a scaffold-free, autologous de novo cartilage implant into standardized full-thickness cartilage defects of femoral condyles in sheep leads to a qualitatively better regenerative tissue than does periosteal flap alone or no treatment., Study Design: Controlled laboratory study., Methods: Chondral defects 4 mm in diameter (1 per sheep) were created in the center of 1 medial femoral condyle of 48 sheep. Twelve defects were allowed to heal spontaneously, 16 defects were covered with periosteal flaps alone, and 20 defects were filled with autologous de novo cartilage graft and overlaid with a periosteal flap. Differences were assessed macroscopically using the International Cartilage Repair Society score and microscopically using the International Cartilage Repair Society histological score and Mankin score at 26 and 52 weeks., Results: The results of the International Cartilage Repair Society Cartilage repair assessment showed that the transplant group was better than was the untreated control at both time periods but not significantly different than was the periosteal flap group. Implanted groups demonstrated a marked improvement in grade of defect filling, cartilage stability, cell distribution, and matrix assessments in each method of assessment. In the transplant group, 2 defects were filled with hyaline cartilage, 5 with mixed hyaline and fibrocartilage, and 2 with fibrocartilage alone., Conclusion: Chondral defects treated with de novo cartilage transplantation show qualitatively better microscopic and macroscopic regeneration than do those treated with periosteal flaps alone., Clinical Relevance: Results of the current study show that third-generation autologous chondrocyte transplantation is a promising development in the field of biologic cartilage regeneration. Future studies should compare this technique with the original Brittberg technique.