ABSTRACT
An in situ study was designed to investigate naturally developed demineralisation in human enamel in a widely non-destructive manner in combination with X-ray microtomography. Samples of human enamel were carried in the oral cavity of participants for 24 h daily for either 21 or 29 days using so-called intraoral mandibular appliances (ICTs). Demineralisation was thereby generated in a natural way without causing caries in the subjects' dentition. By employing synchrotron-based X-ray microtomography (XMT) in combination with volume image analysis, a quantification and three-dimensional visualisation of different stages of mineral density loss was possible. Basic features of the demineralised samples were similar to those reported in earlier in vitro studies. However, the analysed samples showed significant differences in the morphology of surface attack and the degree of mineral density loss depending on the carrier, the exposure time and the position within the ICT. In particular, the varying local conditions within a carrier's oral cavity seem to be different than in an in vitro study. Our results show that the combination of ICTs and quantitative image analysis applied to XMT data provides an analytical tool which is highly suited for the fundamental investigation of naturally developed demineralisation processes.
Subject(s)
Dental Enamel/chemistry , Dental Enamel/diagnostic imaging , Molar, Third/chemistry , Tooth Demineralization , Adult , Female , Humans , Male , Minerals/analysis , Mouth , Pilot Projects , Synchrotrons , X-Ray Microtomography , Young AdultABSTRACT
Postoperative apical growth of epithelium on teeth is a common complication of surgical periodontal therapy. Absorbable textile scaffolds, placed between the operated tooth and its nearby tissues, are considered to serve as a mechanical barrier and prevent undesired apical epithelial growth. They allow local regeneration and new formation of human gingival fibroblasts when the scaffolds are colonized with autologous cells. The aim of this study was to examine proliferation behavior of human gingival fibroblasts on polyglycolic acid (PGA) fleeces with various structural characteristics. The characteristics of the PGA fleeces varied as follows: thickness (1.0-5.0 mm), porosity (85-98%), area mass (56.6-166.9 g/m(2)), and texture. Proliferation of incorporated autologous cells was analyzed by determining the number of live cells, the total absorbed protein, and the degree of cell proliferation. Textile PGA fleeces seem to be suitable as scaffold structures for human gingival fibroblasts. Results showed that structural parameters of fleeces have a significant influence on cell proliferation. Our results showed that a fleece made from knit-de-knit fibers with a porosity of 90% and a thickness of 1.5 mm was most suitable as a scaffold structure and had the highest cell proliferation rate and was superior to fleeces with other structural characteristics.
Subject(s)
Fibroblasts/physiology , Gingiva/physiology , Guided Tissue Regeneration, Periodontal/instrumentation , Polyglycolic Acid/chemistry , Tissue Engineering/instrumentation , Tissue Scaffolds , Biocompatible Materials/chemistry , Cell Proliferation , Cell Survival , Cells, Cultured , Equipment Design , Fibroblasts/cytology , Gingiva/cytology , Guided Tissue Regeneration, Periodontal/methods , Humans , Materials Testing , Pilot Projects , Tissue Engineering/methodsABSTRACT
OBJECTIVE: The postoperative apical growth of epithelium on teeth is a common complication of surgical periodontal therapy. Absorbable textile scaffolds, placed between the operated tooth and its nearby tissues, are considered to serve as a mechanical barrier and prevent undesired apical epithelial growth. They allow local regeneration and the new formation of human gingival fibroblasts when the scaffolds are colonized with autologous cells. The aim of this study was to examine the proliferation behavior of human gingival fibroblasts on polyglycolic acid (PGA) fleeces with various structural characteristics. METHODS: The PGA fleeces varied in the following characteristics: thickness (1.0-5.0 mm), porosity (85%-98%), mass-area ratio (56.6-166.9 g/m(2)), and texture. The proliferation of incorporated autologous cells was analyzed by determining the number of live cells, the total absorbed protein, and the degree of cell proliferation. RESULTS: The results showed that fleece made from Knit-de-Knit textured fibers with a porosity of about 90%, a mass-area between 58 and 84 g/m(2), and a thickness of 1.5 mm was most suitable as a scaffold structure. This fleece showed the highest cell proliferation rate and was superior to fleeces with other structural characteristics. CONCLUSIONS: Textile PGA fleece seems to be suitable as a scaffold structure for human gingival fibroblasts. The structural parameters of the fleece have a significant influence on the proliferation of the cells.
Subject(s)
Biocompatible Materials/chemistry , Fibroblasts/physiology , Gingiva/cytology , Polyglycolic Acid/chemistry , Tissue Scaffolds , Absorption , Adult , Cell Adhesion/physiology , Cell Count , Cell Proliferation , Cell Survival/physiology , Cells, Cultured , Equipment Design , Hot Temperature , Humans , Male , Materials Testing , Microscopy, Electron, Scanning , Pilot Projects , Porosity , Proteins/chemistry , Sterilization/methods , Surface Properties , Time Factors , Water/chemistryABSTRACT
A major complication in the treatment of periodontitis marginalis is the reepithelization of periodontal defects inhibiting collagen fiber attachment and periodontal regeneration. In this study we investigated the possibility of a molecular blockade of epithelial mitosis in vitro. Monoclonal antibodies against the VLA-6 laminin receptor subunit alpha6 interrupted interactions between epithelial cells (HaCaT cells) and their extracellular matrix and thus resulted in reduction of proliferation rates by more than 50%. The same effect was observed with anti alpha1-antibodies. In contrast, collagen-producing and -secreting gingival fibroblasts, which play an important role in periodontal regeneration, remained unaffected by the applied anti alpha6 antibodies. Correspondingly, these cells were found to lack VLA-6 laminin receptors. Selective molecular inhibition of epithelial proliferation and apical migration by monoclonal anti alpha6 antibody application may provide an adjuvant periodontitis therapy resulting in an enhanced periodontal regeneration.
Subject(s)
Antibodies, Monoclonal/pharmacology , Antigens, CD/physiology , Epithelial Attachment/drug effects , Integrins/physiology , Keratinocytes/drug effects , Mitosis/drug effects , Receptors, Laminin/physiology , Cell Line, Transformed , Cell Movement/drug effects , Epithelial Attachment/cytology , Epithelial Attachment/metabolism , Fibroblasts/cytology , Fibroblasts/drug effects , Fibroblasts/metabolism , Humans , Immunohistochemistry , Integrin alpha1 , Integrin alpha6beta1 , Integrins/antagonists & inhibitors , Keratinocytes/cytology , Keratinocytes/metabolism , Periodontium/physiology , Receptors, Laminin/biosynthesis , RegenerationABSTRACT
A major complication in the treatment of periodontitis marginalis is the reepithelization of periodontal defects inhibiting collagen fiber attachment and periodontal regeneration. In this study we investigated the possibility of a molecular blockade of epithelial mitosis in vitro. Monoclonal antibodies against the VLA-6 laminin receptor subunit alpha 6 interrupted interactions between epithelial cells (HaCaT cells) and their extracellular matrix and thus resulted in reduction of proliferation rates by more than 50%. The same effect was observed with anti beta 1-antibodies. In contrast, collagen-producing and -secreting gingival fibroblasts, which play an important role in periodontal regeneration, remained unaffected by the applied anti alpha 6 antibodies. Correspondingly, these cells were found to lack VLA-6 laminin receptors. Selective molecular inhibition of epithelial proliferation and apical migration by monoclonal anti alpha 6 antibody application may provide an adjuvant periodontitis therapy resulting in an enhanced periodontal regeneration.
