Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2014-07-29, 09:08:59 | version 1.30.01
research I I 09implants2_2014 Fig. 3_The tissue reaction to the triphasic bone-substitute material at day 15 after implantation; a) overview of the implanted material within the subcutaneous connective tissue (CT). (H&E-staining, total scan, 100x magnification); b) outer region (OR, double head arrow),with a unique granulation tissue (red arrows: vessels; arrow heads: multinucleated giant cells; (H&E-staining, 200x magnification; scale bar = 100 µm); c) TRAP activity in multinucleated giant cells (red arrow heads; TRAP staining, 200x magnification; scale bar = 100 µm); d) the composition of the inner region (IR) of the implanted material. (arrow heads: multinucleated giant cells; red arrows: vessels; black arrows: mononuclear cells (Movat’s pentachrome staining, 400x magnification; scale bar = 100 µm). Fig. 4_The tissue reaction to the triphasic bone-substitute material at day 30 after implantation; a) total scan of the implant region. Inner circle with few bone substitute remnants (asterisks: granulation tissue; H&E staining, total scan, 100x magnification); b) the former inner region transformed into a granulation tissue. (red arrows: vessels; arrow heads: mutinucleated giant cells; Movat’s pentachrome staining, 400x magnification; scale bar = 100 µm); c) differential TRAP expression at this time point shown by TRAP-negative and TRAP-positive multinucleated giant cells (black arrow heads: TRAP- negative multinucleated giant cells; red arrow heads: TRAP- positive multinucleated giant cells; TRAP-staining, 200x magnification; scale bar = 100 µm). the aforementioned vascularisation parameters to the results of the two control groups (Figs. 7a-d, 8a & b): Tissuereactiontopaste-like -TCPsolution Withintheimplantationbedofthetriphasicpaste- like -TCP at day 3, the bone-substitute material ap- peared as a compact structure. The implanted mate- rial could be divided in compact outer surface and an inner core. A large number of phagocytes, lympho- cytes,afewplasmacellsandeosinophilsandconnec- tivetissuefibresstartedtopenetratetheoutersurface without reaching the inner core. Therefore neither vessels nor connective tissue or organic structures were found in the central parts of the implantation bed (Figs. 1a–c). At day 10 the separation within the biomaterial wasstillpresent.Theouterstructurecontainedanac- tivegranulationtissue,withanincreasedvascularisa- tion by newly formed vessels, while the inner core, comparable to day 3, was still populated by very few mononuclear cells (Figs. 2a–e). At day 15, the degradation of the outer structure proceeded.Thegranulationtissueformedaroundthe biomaterial was rich in vessels and contained more multinucleatedgiantcellsthanatday10.Intheinner core still less connective tissue fibres and mononu- clear and especially multinuclear cells were de- tectable compared to the outer regions (Figs. 3a–d). The implantation bed showed total integration of theinnerandouterpartoftheimplantedbiomaterial at day 30. TRAP positive multinucleated giant cells dominated the fiber and vessel rich granulation tis- sue. The former outer region had been transformed intoaconnectivetissuewithveryfewphagocytesand rich in fibres, while the inner core of the implant had been transformed into a richly vascularized granula- tion tissue (Figs. 4a & c). To the end of the observation at day 60 the degra- dation of the biomaterial, mainly by multinucleated giant cells continued. In areas, where biomaterial remnants were still present, granulation tissue was stillpresent,whileinpartswherethebiomaterialwas already completely degraded, it was replaced by adi- poseandconnectivetissue.Remaininggranuleswere surrounded by phagocytes, i.e. macrophages and multinucleated giant cells (Figs. 5a & c, 6a–d). Histomorphometricresults Histomorphometricinvestigationoftheexplanted biomaterials was performed to determine the vascu- larisation within the implantation bed at different timepointsofbiomaterialintegration.Atday3amild vascularisation within the three phasic injectable -TCP biomaterial, which was significantly higher than in the -TCP granule group, was observed (**p<0.01,Figs.8a&b).Atdays10,15,30and60sig- nificantly higher values for percent vascularisation and vessel density in the -TCP paste were observed compared to the solid -TCP and the two control groups (sham operation and sodium chloride). These data indicated a maturing of the vessels within the implant.Adetailedoverviewofthesignificancelevels between the different groups at each time point is given in figure 8a & b. _Discussion Inthepresentstudythetissuereactionstoapaste- like bone substitute material composed of -TCP, methylcelluloseandhyaluronicacidwasinvestigated in the subcutaneous implantation model in Wistar ratsover60days.Implantationofpuresolid-TCP,in- jectionofsodiumchlorideandshamoperationserved ascontrols.Theprimaryfocusofhistologicalandhis- Fig. 3a Fig. 3c Fig. 3b Fig. 3d Fig. 4a Fig. 4cFig. 4b