Suchergebnisse

Our objective is to evaluate the regional regenerative potential of calvarial bone in criticalsized defects in a rabbit model using novel nanostructured silica-loaded membranes doped with zinc or doxycycline. Nanostructured membranes of (MMA)1-co-(HEMA)1/(MA)3-co-(HEA)2 loaded with 5 wt% of SiO2 nanoparticles (HOOC-Si-Membranes) were doped with zinc (Zn-HOOC-Si- Membrane) or doxycycline (Dox-HOOC-Si-Membrane). Critical bone defects were created on six New-Zealand-breed rabbit skulls and covered with the membranes. A sham defect without a membrane was used as the control. After six weeks, a histological analysis (toluidine blue technique) was employed to determine the area percentages of newly formed bone, osteoid bone, and soft tissue. The measurements were performed by dividing the total defect area into top (close to the membrane) and bottom (close to the dura mater) regions, or peripheral (adjacent to the old bone) and central (the sum of the remaining zones) regions. The peripheral regions of the defects showed higher osteogenic capacity than the central areas when the membranes were present. The proportion of new bone adjacent to the dura was similar to that adjacent to the membrane only when the HOOC-Si-Membranes and Zn-HOOC-Si-Membranes were used, indicating a direct osteoinductive effect of the membranes. ; Spanish Government ; European Commission PID2020-114694RBI00 ; Ministry of Universities FPU20/00450

This work was supported by: (1) the Ministry of Economy and Competitiveness and the European Regional Development Fund (Project PID2020-114694RB-100 MINECO/AEI/FEDER/UE), (2) the University of Granada/Regional Government of Andalusia Research Fund from Spain, and the European Regional Development Fund (A-BIO-157-UGR-18/FEDER). This research is part of C.V.'s PhD research study. ; Collagen matrices have become a great alternative to the use of connective tissue grafts for soft tissue augmentation procedures. One of the main problems with these matrices is their volume instability and rapid degradation. This study has been designed with the objective of examining the degradation of three matrices over time. For this purpose, pieces of 10 10 mm2 of Fibro-Gide, Mucograft and Mucoderm were submitted to three different degradation tests— (1) hydrolytic degradation in phosphate buffer solution (PBS); (2) enzyme resistance, using a 0.25% porcine trypsin solution; and (3) bacterial collagenase resistance (Clostridium histolyticum)—over different immersion periods of up to 50 days. Weight measurements were performed with an analytic microbalance. Thickness was measured with a digital caliper. A stereomicroscope was used to obtain the matrices' images. ANOVA and Student–Newman–Keuls tests were used for mean comparisons (p < 0.05), except when analyzing differences between time-points within the same matrix and solution, where pair-wise comparisons were applied (p < 0.001). Fibro-Gide attained the highest resistance to all degradation challenges. The bacterial collagenase solution was shown to constitute the most aggressive test as all matrices presented 100% degradation before 14 days of storage. ; Ministry of Economy and Competitiveness ; European Commission PID2020-114694RB-100 A-BIO-157-UGR-18/FEDER ; University of Granada/Regional Government of Andalusia Research Fund from Spain

This work was supported by: (1) the Ministry of Economy and Competitiveness and European Regional Development Fund [Project PID2020-114694RB-100 MINECO/AEI/FEDER/UE], (2) University of Granada/Regional Government of Andalusia Research Fund from Spain and European Regional Development Fund (A-BIO-157-UGR-18/FEDER). ; Collagen membranes are currently the most widely used membranes for guided bone regeneration; however, their rapid degradation kinetics means that the barrier function may not remain for enough time to permit tissue regeneration to happen. The origin of collagen may have an important effect on the resistance to degradation. The aim of this study was to investigate the biodegradation pattern of five collagen membranes from different origins: Biocollagen, Heart, Evolution X-fine, CopiOs and Parasorb Resodont. Membranes samples were submitted to different degradation tests: (1) hydrolytic degradation in phosphate buffer saline solution, (2) bacterial collagenase from Clostridium histolyticum solution, and (3) enzyme resistance using a 0.25% porcine trypsin solution. Immersion periods from 1 up to 50 days were performed. At each time point, thickness and weight measurements were performed with a digital caliper and an analytic microbalance, respectively. ANOVA and Student–Newman–Keuls tests were used for comparisons (p < 0.05). Differences between time-points within the same membranes and solutions were assessed by pair-wise comparisons (p < 0.001). The Evolution X-fine collagen membrane from porcine pericardium attained the highest resistance to all of the degradation tests. Biocollagen and Parasorb Resodont, both from equine origin, experienced the greatest degradation when immersed in PBS, trypsin and C. histolyticum during challenge tests. The bacterial collagenase solution was shown to be the most aggressive testing method. ; Ministry of Economy and Competitiveness PID2020-114694RB-100 ; European Commission PID2020-114694RB-100 A-BIO-157-UGR-18/FEDER ; University of Granada/Regional Government of Andalusia Research Fund from Spain A-BIO-157-UGR-18/FEDER

This work was supported by: (1) the Ministry of Economy and Competitiveness and European Regional Development Fund [Project MAT2017-85999-P MINECO/AEI/FEDER/UE], (2) University of Granada/Regional Government of Andalusia Research Fund from Spain and European Regional Development Fund (A-BIO-157-UGR-18/FEDER). This research is part of C.V.'s PhD research study. ; Soft tissues have been shown to be critical for the maintenance of both teeth and implants. Currently, regenerative soft tissue techniques propose the use of collagen matrices, which can avoid the drawbacks derived from the obtainment of autogenous tissue graft. A systematic review and meta-analysis were conducted to ascertain the efficacy of collagen matrices (CM) compared to autogenous connective tissue graft (CTG) to improve soft tissue dimensions. An electronic and manual literature searches were performed to identify randomized clinical trials (RCT) or controlled clinical trials (CCT) that compared CTG and CM. Pooled data of width of keratinized tissue (KT) and mucosal thickness (MT) were collected and weighted means were calculated. Heterogeneity was determined using Higgins (I-2). If I-2 > 50% a random-effects model was applied. Nineteen studies were included based on the eligibility criteria. When using CTG a higher MT gain (0.32 mm, ranging from 0.49 to 0.16 mm) was obtained than when employing CM. Similar result was obtained for the width of KT gain, that was 0.46 mm higher (ranging from 0.89 to 0.02 mm) when employing CTG. However, it can be stated that, although autogenous CTG achieves higher values, CM are an effective alternative in terms of total width of KT and MT gain. ; Ministry of Economy and Competitiveness MAT2017-85999-P MINECO/AEI/FEDER/UE ; European Commission MAT2017-85999-P MINECO/AEI/FEDER/UE A-BIO-157-UGR-18/FEDER ; University of Granada/Regional Government of Andalusia Research Fund from Spain

The authors would like to thank M.F. Vallecillo for his generosity in kindly offering us his photo collection from the Master of Surgery and Implantology, which has allowed us to illustrate this work. ; Oral soft tissue thickening or grafting procedures are often necessary to cover tooth recession, re-establish an adequate width of keratinized tissue, correct mucogingival deformities improving esthetics, prepare a site for an implant or prosthetics, for ridge preservation procedures, and soft tissue contouring around dental implants. Gingival recession and root or implant exposure are commonly associated and have led to mucogingival deficiencies that have traditionally been treated with free gingival grafts and autogenous soft tissue grafts. The latter represents the gold standard in acquiring a functionally adequate zone of keratinized attached gingiva. However, soft tissue substitutes are more usually employed because they lessen morbidity and abbreviate surgical time. This review is aimed at assessing oral soft tissue augmentation techniques and biomaterials used from existing literature, principally concerning sca olds from both human and animal-based tissue derivatives matrices. In order to avoid the use of human donor tissue, the xenogenic collagen matrices are proposed for soft tissue augmentation. In general, all of them have provided the remodeling processes and enhanced the formation of new connective tissue within the matrix body. ; Ministry of Economy and Competitiveness ; European Union (EU) MAT2017-85999P ; Government of Andalusia ; European Union (EU) A-BIO-157-UGR-18

This work was funded by the Ministry of Economy and Competitiveness and European Regional Development Fund (MINECO/FEDER MAT2017-85999P) and Government of Andalusia and FEDER (A-BIO-157-UGR-18). ; Most of the polymers used as biomaterials for scaffolds are naturally occurring, synthetic biodegradable, and synthetic non-biodegradable polymers. Since synthetic polymers can be adapted for obtaining singular desired characteristics by applying various fabrication techniques, their use has increased in the biomedical field, in dentistry in particular. The manufacturing methods of these new structures include many processes, such as electrospinning, 3D printing, or the use of computer-aided design/computer-aided manufacturing (CAD/CAM). Synthetic polymers show several drawbacks that can limit their use in clinical applications, such as the lack of cellular recognition, biodegradability, and biocompatibility. Moreover, concerning biodegradable polymers, the time for matrix resorption is not predictable, and non-resorbable matrices are preferred for soft tissue augmentation in the oral cavity. This review aimed to determine a new biomaterial to offset the present shortcomings in the oral environment. Researchers have recently proposed a novel non-resorbable composite membrane manufactured via electrospinning that has allowed obtaining remarkable in vivo outcomes concerning angiogenesis and immunomodulation throughout the polarization of macrophages. A prototype of the protocol for in vitro and in vivo experimentation with hydrogels is explained in order to encourage innovation into the development of promising biomaterials for soft tissue augmentation in the near future. ; Ministry of Economy and Competitiveness (MINECO/FEDER) MAT2017-85999P ; European Union (EU) MAT2017-85999P ; Government of Andalusia A-BIO-157-UGR-18 ; European Union (EU) A-BIO-157-UGR-18

This work was funded by the Ministry of Economy and Competitiveness and European Regional Development Fund (MINECO/FEDER MAT2017-85999P). University of Granada/Regional Government of Andalusia Research Fund from Spain and European Regional Development Fund (A-BIO-157-UGR-18/FEDER). This research is part of M.T-O.'s Ph.D. research study. ; The data presented in this study are available on request from the corresponding author. ; Alveolar bone ridge resorption occurred after natural teeth loss and it can restrict the possibility of dental implants placement. The use of bone regenerative procedures is frequently required. The existing evidence regarding the efficacy of horizontal bone ridge augmentation trough guided bone regeneration (GBR) using polymeric membranes was stated. A systematic review and meta-analysis were performed. Electronic and manual literature searches were conducted. Screening process was done using the National Library of Medicine (MEDLINE by PubMed), Embase, and the Cochrane Oral Health. Included articles were randomized controlled trials and observational studies. Weighted means were calculated. Heterogeneity was determined using Higgins (I2). If I2 > 50% a random-effects model was applied. It was found that the mean of horizontal bone gain was 3.95 mm, ranging from 3.19 to 4.70 mm (confidence interval 95%). Heterogeneity is I2 = 99% (confidence interval 95%) and significance of the random-effects model was p < 0.001. The complications rate was 8.4% and membrane exposure was the most frequent. Through this study, we were able to conclude that the existing scientific evidence suggests that GBR using polymeric membranes is a predictable technique for achieving horizontal bone augmentation, thus, permitting a proper further implant placement. ; Ministry of Economy and Competitiveness MINECO/FEDER MAT2017-85999P ; European Commission MINECO/FEDER MAT2017-85999P A-BIO-157-UGR-18/FEDER ; University of Granada/Regional Government of Andalusia Research Fund from Spain

This work was funded by the University of Granada/Regional Government of Andalusia Research Fund from Spain and European Regional Development Fund (A-BIO-157-UGR-18/FEDER). ; Barrier membranes are employed in guided bone regeneration (GBR) to facilitate bone in-growth. A bioactive and biomimetic Zn-doped membrane with the ability to participate in bone healing and regeneration is necessary. The aim of the present study is to state the effect of doping the membranes for GBR with zinc compounds in the improvement of bone regeneration. A literature search was conducted using electronic databases, such as PubMed, MEDLINE, DIMDI, Embase, Scopus andWeb of Science. A narrative exploratory review was undertaken, focusing on the antibacterial effects, physicochemical and biological properties of Zn-loaded membranes. Bioactivity, bone formation and cytotoxicity were analyzed. Microstructure and mechanical properties of these membranes were also determined. Zn-doped membranes have inhibited in vivo and in vitro bacterial colonization. Zn-alloy and Zn-doped membranes attained good biocompatibility and were found to be non-toxic to cells. The Zn-doped matrices showed feasible mechanical properties, such as flexibility, strength, complex modulus and tan delta. Zn incorporation in polymeric membranes provided the highest regenerative efficiency for bone healing in experimental animals, potentiating osteogenesis, angiogenesis, biological activity and a balanced remodeling. Zn-loaded membranes doped with SiO2 nanoparticles have performed as bioactive modulators provoking an M2 macrophage increase and are a potential biomaterial for promoting bone repair. Zn-doped membranes have promoted pro-healing phenotypes. ; University of Granada/Regional Government of Andalusia Research Fund from Spain ; European Commission A-BIO-157-UGR-18/FEDER