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Tissue Reactions (tissue + reaction)
Selected AbstractsTissue reaction initiated by different sealersINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2003M. Bernáth No abstract is available for this article. [source] Tissue reaction and biodegradation of implanted cross-linked high amylose starch in ratsJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 6 2002Cyril Désévaux Abstract The biocompatibility and degradation characteristics of cross-linked high amylose starch (Contramid®) were investigated in rats over 4 months. Contramid® pellets (3-mm diameter and thickness) obtained by direct compression, were implanted subcutaneously and intramuscularly. On sequential time points, macroscopic observations of implantation sites were performed and tissue samples were removed, fixed, and histologically evaluated. No macroscopic inflammatory reaction was observed with Contramid®. Upon histologic examination, inflammatory reaction produced by Contramid® was moderate and restricted to implantation sites. The sequence of inflammatory events with Contramid® was similar regardless of implantation site. Degradation of Contramid® pellets was characterized by fragmentation with formation of fibrovascular septa and phagocytosis by macrophages. Finally Contramid® was mostly absorbed by the end of the 4-month period and substituted by adipocytes. It has been demonstrated that Contramid® is a biocompatible and absorbable material. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 772,779, 2002 [source] Tissue reaction to liquid silicone simulating low-grade liposarcoma following lip augmentationJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 5 2004Alexander Maly We report the case of a 32-year-old woman who underwent silicone injection into the upper lip 2 years prior to presenting with masses clinically suspicious for tumor and interpreted on biopsy as low-grade liposarcoma. Lack of pre-operative history of silicone injection almost led to unnecessary surgery. This complicated situation may arise when reaction to liquid or gel silicone histologically closely simulates a low-grade liposarcoma. Clinical and pathological correlations are of critical assistance in making the correct pre-operative diagnosis and avoiding unnecessary traumatic surgical intervention. [source] Tissue reaction to orthodontic tooth movement in different bone turnover conditionsORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 3 2003C. Verna Structured Abstract Authors , Verna C, Melsen B Objectives , To study the tissue reaction to orthodontic load in normal, high, and low bone turnover states. Design , ,Split mouth' design performing orthodontic tooth movement in 52, 6-month-old male rats with: normal (n = 19), high (n = 16), and low bone turnover (n = 17), the latter two being obtained by induction of hyperthyroidism and hypothyroidism, respectively. Performed at the Department of Orthodontics at Aarhus University. Experimental Variable , The upper left first molar was moved for 21 days. Bone markers were administered 7 and 2 days before killing. Histological sections were cut at the coronal and apical levels. Outcome Measure , Alveolar socket area, periodontal ligament width, the relative extension of alveolar wall with erosion surfaces, and the mineralizing surfaces were measured and compared in the three groups. Results , Alveolar socket, periodontal ligament width, and erosion surface were larger on the treated than on the control side in the three groups. The normal and hypothyroid groups showed a wider periodontal ligament at the bucco-distal site at the coronal level, while the hyperthyroid group showed a widening which was not spatially oriented. The normal and hyperthyroid groups showed higher erosion at the corono-mesial site. The mineralizing surfaces were larger on the treated than on the control side in the normal and hypothyroid groups, but not in the hyperthyroid group. Conclusion , In the hyperthyroid group, the widening of the periodontal ligament was not spatially oriented and the increased erosion was not accompanied by increased formation, as observed in the normal and hypothyroid groups. [source] Tissue reaction of the rabbit urinary bladder to tension-free vaginal tape and porcine small intestinal submucosaBJU INTERNATIONAL, Issue 6 2002D.M. Rabah Objectives ,To compare the histological tissue reactions of urinary bladder in close contact with polypropylene mesh tension-free vaginal tape (TVT) or porcine small intestinal submucosal (SIS) grafts, as the commercial availability of various materials has considerably simplified sling procedures for treating urinary incontinence, but erosion and infection after using artificial sling materials remain an important concern. Materials and methods ,Thirty female New Zealand rabbits were randomized to three groups, i.e. group A (TVT, 12 animals), group B (SIS, 12) and group C (surgical control, six). Through a laparotomy under anaesthesia and an aseptic technique, the bladder was approached at its dome, where a 0.5 × 1 cm piece of TVT or SIS was fixed in direct contact with the bladder wall. The control group underwent only bladder manipulation with no material applied. Half the animals in each group were killed after 6 weeks and the other half after 12 weeks. The urinary bladder was harvested and examined histologically. Results ,The grafts in both groups were characterized by dense foreign-body type reactions and were mostly attached loosely to the bladder wall by a thin layer of fibrovascular tissue. More importantly, the bladder wall reactions showed no inflammation in all 12 animals in group A (TVT) but three of them had various grades of fibrosis. There was severe transmural inflammation in one animal in group B (SIS); one rabbit had grade I and two had grade II fibrosis. The controls, as expected, showed no bladder wall reactions. Conclusion ,In this descriptive analysis of reaction types elicited on the urinary bladder by these grafts, both materials appeared to be safe. Although TVT elicited fewer and less severe adverse reactions, no statistical conclusions can be drawn. The clinical significance of these findings should emerge from long-term clinical data when they become available. [source] Tissue reactions to sutures in the presence and absence of anti-infective therapyJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2005Knut N. Leknes Abstract Background: In the oral cavity, sutures are placed within tissues of high vascularity in a moist environment with infectious potential. The objective of this study was to evaluate tissue reactions at silk and expanded polytetrafluoroethylene (ePTFE) sutures in the presence and absence of anti-infective therapy (AT). Methods: Thirty-six sutures were placed within the mandibular keratinized gingiva in six Beagle dogs. Each animal received one braided silk (4-0) and one ePTFE (CV-5) suture in contra-lateral jaw quadrants at 14, 7, and 3 days prior to biopsy. Three animals received daily AT including topical 2% chlorhexidine solution and a systemic broad-spectrum antibiotic. Biopsy specimens allowed histometric analysis of tissue reactions along the central part of the suture loop including the area of perisutural epithelium, ratio inflammatory cells (ICs)/epithelial cells and IC/fibroblasts, and presence/absence of bacterial plaque in the suture track. Results: A perisutural epithelial sheath was forming within 3 days. The cross-sectional area of the epithelium increased with time for both suture materials (p=0.003) but was particularly pronounced for the silk sutures in the absence of AT. Clusters of IC were present in the perisutural connective tissue and epithelium. Over time, a more prominent increase in IC/fibroblasts was evident for the silk sutures in the absence of AT. The pooled material revealed a significantly higher IC/fibroblast ratio for silk compared with ePTFE sutures (p=0.017). Bacterial plaque influx was detected in 6/9 silk and 0/9 ePTFE suture channels in the presence, and 6/6 and 3/6 suture channels, respectively, in the absence of AT. Conclusions: AT may reduce biofilm formation and inflammation along the suture track. Braided silk, however, elicits more severe tissue reactions than ePTFE regardless of infection control. [source] Histological evaluation of MTA as a root-end filling materialINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2007P. F. E. Bernabé Abstract Aim, To assess the histological response associated with grey mineral trioxide aggregate (GMTA) and zinc oxide eugenol (ZOE) as root-end filling materials in teeth where the root canals were not filled and the coronal access cavities were not restored. Methodology, Periapical lesions were developed in 24 premolar teeth in three dogs. The root canals were prepared and half of them were dried, filled and the coronal access restored (closed). The remaining teeth were not root filled and no coronal restoration was placed (open). Apical root-end resections were performed 3 mm from the apex, and root-end cavities were prepared with ultrasonic tips. These were randomly filled with either ZOE or GMTA in the same number of specimens using MAPSYSTEM device. After 180 days the animals were killed and blocks of tissues removed and processed for histological examination. Periradicular tissue reaction was evaluated, including severity of inflammation and cementum formation. Statistical analysis was performed using anova analysis and Tukey's test. Results, A significant difference was found between the levels of inflammation in the periradicular tissues of the GMTA/closed group, compared with the ZOE/open and ZOE/closed groups (P < 0.05) but not between GMTA/closed and GMTA/open groups. Cementum formation was not found over any ZOE specimens but over MTA in all specimens. No microorganisms were found in the interface between the material and the dentinal walls. Conclusions, GMTA was associated with less periapical inflammation and tissue response when used as a root-end filling material, even when no root filling or coronal restoration was present. [source] Tissue granuloma structure-function in experimental visceral leishmaniasisINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 5 2001Henry W. Murray In experimental visceral leishmaniasis in normal mice (BALB/c, C57BL/6) acquired resistance to Leishmania donovani, a protozoan which targets tissue macrophages, depends upon T cells, Th1 cell-type cytokine generation and activated mononuclear phagocytes. In the intact host, initial control and eventual resolution of L. donovani hepatic infection in normal mice is expressed by and accomplished within well-formed, mature tissue granulomas. In the liver, these immunologically active, inflammatory structures are assembled around a core of fused, parasitized resident macrophages (Kupffer cells) which come to be encircled by both cytokine-secreting T cells and influxing leishmanicidal blood monocytes. This pro-host defense granuloma structure-function relationship, in which histologically mature granulomas provide the microenvironment for intracellular L. donovani killing, however, is only one of seven which have been identified through experimental modifications in this model. This report reviews these structure-function relationships and illustrates the broad spectrum of additional possible responses. These responses range from structurally intact granulomas which provide no antileishmanial function (the ,ineffective' granuloma), to enlarged granulomas which show enhanced parasite killing (the ,hypertrophied' granuloma), to effective antileishmanial activity in the absence of any tissue reaction (the ,invisible' granuloma). [source] Effects of temperature on disease progression and swimming stamina in Ichthyophonus -infected rainbow trout, Oncorhynchus mykiss (Walbaum)JOURNAL OF FISH DISEASES, Issue 10 2009R Kocan Abstract Rainbow trout, Oncorhynchus mykiss, were infected with Ichthyophonus sp. and held at 10 °C, 15 °C and 20 °C for 28 days to monitor mortality and disease progression. Infected fish demonstrated more rapid onset of disease, higher parasite load, more severe host tissue reaction and reduced mean-day-to-death at higher temperature. In a second experiment, Ichthyophonus -infected fish were reared at 15 °C for 16 weeks then subjected to forced swimming at 10 °C, 15 °C and 20 °C. Stamina improved significantly with increased temperature in uninfected fish; however, this was not observed for infected fish. The difference in performance between infected and uninfected fish became significant at 15 °C (P = 0.02) and highly significant at 20 °C (P = 0.005). These results have implications for changes in the ecology of fish diseases in the face of global warming and demonstrate the effects of higher temperature on the progression and severity of ichthyophoniasis as well as on swimming stamina, a critical fitness trait of salmonids. This study helps explain field observations showing the recent emergence of clinical ichthyophoniasis in Yukon River Chinook salmon later in their spawning migration when water temperatures were high, as well as the apparent failure of a substantial percentage of infected fish to successfully reach their natal spawning areas. [source] Use of ultrasonography to facilitate surgical removal of non-enteric foreign bodies in 17 dogsJOURNAL OF SMALL ANIMAL PRACTICE, Issue 8 2004K. L. Staudte Plant material foreign bodies may cause vague clinical signs at the time of initial presentation but can progress to cause persistent or recurrent abscessation, sinus tract formation and debilitating disease, due to migration of the foreign body, severe tissue reaction and secondary infection. Ultrasonography is a non-invasive technique that can be used to identify precisely the presence, location and size of radiolucent foreign bodies. Early identification of foreign bodies using ultrasonography facilitates surgical retrieval before further migration and tissue injury occur. This paper reviews the ultrasonographic findings and outcome in 17 dogs with non-enteric, radiolucent, plant material foreign bodies. [source] Sarcoid tissue reaction on herpes zoster scars in a myelodysplastic syndrome patient: Wolf's isotopic responseJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 4 2009D Watanabe [source] Continuous peripheral nerve block catheter tip adhesion in a rat modelACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2006C. C. Buckenmaier III Background:, Continuous peripheral nerve block (CPNB) has been used effectively in combat casualties from Iraq and Afghanistan to provide surgical anesthesia and extended duration analgesia during evacuation and convalescence. Little information is available concerning catheter tip tissue reaction with prolonged use. Methods:, Forty-eight male Sprague-Dawley rats were assigned (12 per group) to one of four catheter tip designs provided by Arrow International: group A, 20-gauge catheter with three side-holes and a bullet-shaped tip; group B, 19-gauge StimuCathÔ catheter with coiled omni-port end with hemispherical distal tip; group C, 19-gauge catheter with single end-hole in conducting tip; group D, 19-gauge catheter with closed conducting tip with four side-holes. Following laparotomy, a randomly assigned catheter tip was sutured to the parietal peritoneal wall with the tip extending between experimental injuries created on the abdominal wall and cecum. After 7 days in situ, the catheter tips were removed from the adhesion mass using a force gauge, and the grams of force needed for removal were recorded. Results:, The mean force ± standard deviation values were 1.09 ± 1.21 g for group A, 21.20 ± 30.15 g for group B, 0.88 ± 1.47 g for group C and 1.60 ± 2.50 g for group D. The variation of each catheter group mean force compared with that of group B was significant (P < 0.05). There was no significant difference in adhesion force between groups A, C and D. Conclusions:, These results suggest that the manufactured design of a CPNB catheter tip can contribute to the adhesion of the tip in an intense inflammatory environment. This finding may have important clinical implications for CPNB catheters left in place for extended periods of time. [source] Effect of fluence on efficacy using the 1440 nm laser with CAP technology for the treatment of rhytids,LASERS IN SURGERY AND MEDICINE, Issue 6 2008Jenifer R. Lloyd D.O. Abstract Background and Objective The objective of this study was to evaluate the effect of fluence on the treatment of rhytids using a 1440 nm laser with CAPSM technology and the T350 tip. Study Design/Materials and Methods Twelve subjects with rhytids were enrolled in an IRB approved study. The AffirmÔ laser with CAP technology (Cynosure, Inc., Westford, MA) 1440 nm, 10 mm T350, 2 milliseconds, 1.5 Hz was used at fluences ranging from 3.0 to 5.5 J/cm2 in a split face study. At each treatment visit, fluences on the right side of the face were held constant at 3.0 J/cm2, while the left side of the face started at 3.0 J/cm2 and increased 0.5 J/cm2 with each treatment to a maximum of 5.5 J/cm2. Five treatments were given at 2-week intervals using the SmartCoolÔ (Cynosure, Inc.). Photographic comparisons at baseline and 3 months were used to compare fluence results as well as to evaluate for efficacy in the treatment of rhytids. The following standard scale was employed: Poor (0,25%), Fair (26,50%), Good (51,75%), and Excellent (76,100%). In addition, following the study, a few subjects received a series of laser pulses at increasing fluences on their buttocks to further evaluate the effect of fluence on tissue reaction. Results Comparing the right and left photographic results, no clinically observable differences were noted. Both sides received the same grade in all cases. Five subjects (42%) were noted to have Good results, three (25%) were given a rating of Fair, and four (33%) were given a Poor result with little or no improvement observed. The follow-up buttock fluence study demonstrated an effect threshold at 3.0 J/cm2. Conclusion The 1440 nm laser with CAP technology can provide overall improvement in patients with rhytids at moderate fluences. Increasing the fluence does not appear to increase efficacy. Lesers Surg. Med. 40:387,389, 2008. © 2008 Wiley-Liss, Inc. [source] Tissue reaction to orthodontic tooth movement in different bone turnover conditionsORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 3 2003C. Verna Structured Abstract Authors , Verna C, Melsen B Objectives , To study the tissue reaction to orthodontic load in normal, high, and low bone turnover states. Design , ,Split mouth' design performing orthodontic tooth movement in 52, 6-month-old male rats with: normal (n = 19), high (n = 16), and low bone turnover (n = 17), the latter two being obtained by induction of hyperthyroidism and hypothyroidism, respectively. Performed at the Department of Orthodontics at Aarhus University. Experimental Variable , The upper left first molar was moved for 21 days. Bone markers were administered 7 and 2 days before killing. Histological sections were cut at the coronal and apical levels. Outcome Measure , Alveolar socket area, periodontal ligament width, the relative extension of alveolar wall with erosion surfaces, and the mineralizing surfaces were measured and compared in the three groups. Results , Alveolar socket, periodontal ligament width, and erosion surface were larger on the treated than on the control side in the three groups. The normal and hypothyroid groups showed a wider periodontal ligament at the bucco-distal site at the coronal level, while the hyperthyroid group showed a widening which was not spatially oriented. The normal and hyperthyroid groups showed higher erosion at the corono-mesial site. The mineralizing surfaces were larger on the treated than on the control side in the normal and hypothyroid groups, but not in the hyperthyroid group. Conclusion , In the hyperthyroid group, the widening of the periodontal ligament was not spatially oriented and the increased erosion was not accompanied by increased formation, as observed in the normal and hypothyroid groups. [source] Microvascular Angiogenesis and Apoptosis in the Survival of Free Fat Grafts ,THE LARYNGOSCOPE, Issue 8 2000Toshiro Nishimura MD Abstract Objectives/Hypothesis Autologous fat is an ideal material for augmentation in plastic surgery because of its minimal tissue reaction and easy availability, but its long-term graft survival is somewhat unpredictable. This study was conducted to determine how fat grafts get their vascular supply from the recipient bed and why they keep reducing in volume and weight. Study Design Experimental study using animal models. Methods The expression of vascular endothelial growth factor (VEGF) in grafted fat tissue was examined by using immunohistochemical staining, and apoptotic cell death in the grafted fat was studied by using terminal deoxynucleotidyl transferase (TdT),mediated deoxy-uridine triphosphate (dUTP)-biotin nick end-labeling method. Twenty-five Wistar rats were used as models of free fat grafts. Fat tissue taken from inguinal fat pads was grafted to the back skin with an 18-gauge needle injection. Results The weight of the injected fat was significantly reduced on the 180th day compared with the original weight (32% ± 10%). VEGF+ cells were observed in fibrous connective tissue of the grafts on days 7 and 30 but not after day 90. Apoptotic cells were also observed on days 7 and 30. Conclusions Angiogenic factors including VEGF started to revascularize the graft around day 7, and the extent of the vasculature was not reduced after the revascularization. In addition to necrosis in the graft's early stages, apoptosis induced by many factors in the graft's environment is also, at least in part, a cause of long-term volume reduction of the fat graft. Thus clinical application of angiogenic factors such as VEGF to fat grafts and control of apoptosis may contribute to improvements in fat-grafting techniques. [source] ,Activation-induced cell death': a special program able to preserve the homeostasis of the skin?EXPERIMENTAL DERMATOLOGY, Issue 1 2002Giuseppe De Panfilis Abstract: The ,activation-induced cell death' (AICD) is a molecular system leading to death of antigen-activated T lymphocytes, in order to avoid accumulation of harmful cytokine-releasing cells. This article reviews both the molecular mechanisms working in AICD and the role played by such mechanisms in preventing a number of skin diseases. Specifically, because AICD removes activated and autoreactive T cells through a CD95-/CD95-L-mediated suicide, skin diseases were scrutinized in which such valuable machinery could be lacking. Indeed, at least some inflammatory skin diseases, including psoriasis and atopic dermatitis, can be sustained by an increased survival of activated T lymphocytes associated with deficient CD95-/CD95-L-mediated AICD of such strong pro-inflammatory cells. In addition, autoreactive skin diseases, including, e.g. alopecia areata, lichen planus and other lichenoid tissue reactions, can be related to autoreactive T lymphocytes which could be unable to undergo CD95-/CD95-L-mediated AICD. Finally, a lack of AICD may be executive even in favoring cutaneous T cell lymphoma. Thus, because inflammatory, autoreactive and neoplastic skin diseases can be associated with a deficient CD95-/CD95-L-mediated suicide of activated T cells, AICD is likely to represent a fundamental program to preserve the homeostasis of the skin. Therapeutic approaches able to restore the AICD machinery promise to successfully treat such relevant skin diseases. [source] Type and ultrastructure of Didymocystis wedli and Koellikerioides intestinalis (Digenea, Didymozoidae) cysts in captive Atlantic bluefin tuna (Thunnus thynnus Linnaeus, 1758)JOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2009I. Mladineo Summary Tissue encapsulation, one of the most common tissue reactions to invading parasites, is the hallmark sign of didymozoid (Digenea, Didymozoidae) infections in fish. Investigated were the types of intermediate filaments and ultrastructure of the connective tissue capsule elicited by the presence of didymozoids in the gills and intestine of Atlantic bluefin tuna (Thunnus thynnus Linnaeus, 1758). The evaluation was done performing TEM microscopy of two tissue-embedded didymozoid species, along with monoclonal antibodies labeling (anti-fish collagen type I, anti-human cytokeratin, anti-vimentin antibodies). Ultrastructure of Didymocystis wedli (Ariola, 1902) (prevalence = 61.75%, abundance = 28.91) encapsulated in gill filaments and Koellikerioides intestinalis (Yamaguti, 1970) (prevalence = 54.65%, abundance = 10.96) in the intestinal submucosa showed that the thin parasitic hindbody tegumentum was directly embedded in layers of connective tissue bands. Only a few cellular elements (lymphocytes, fibroblasts and fibrocytes) infiltrated the connective tissue capsule, which differed between the two didymozoid species in thickness, not in the type of filaments expressed. Cysts showed positive reaction to extracellular collagen as well as appearing positive for the cytoskeletal intermediate filaments vimentin and cytokeratin. [source] Hemocompatibility, biocompatibility, inflammatory and in vivo studies of primary reference materials low-density polyethylene and polydimethylsiloxane: A reviewJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 5 2001Claire Bélanger, Marie Abstract In 1984, low-density polyethylene (LDPE) and polymethylsiloxane (PDMS), two primary reference materials (PRM), were made available by the National Heart, Lung, and Blood Institute (NHLBI) as discriminatory tools for the validation of standardized and novel in vitro and in vivo tests in the evaluation of biomaterials. This article reviews the results and conclusions obtained by several studies investigating the hemocompatibility, in vitro biocompatibility, inflammatory response, and in vivo tissue reactions of these two reference materials. Variable results obtained with LDPE and PDMS in ex vivo hemocompatibility studies were attributed to the type of animal model used, the flow velocity of the circulating blood, the time of exposure, and the methodology used to measure blood cell adhesion or activation at the surface of the materials. In contrast, both the LDPE and PDMS appeared to be suitable reference materials when used in in vitro biocompatibility, inflammatory response, and in vivo studies. However, caution must be taken when interpreting the results, because gamma sterilization of these two materials as well as their origin (for example PDMS) are two critically important factors. In conclusion, we see a definite need for standardized hemocompatible parameters and better high-quality hemocompatibility studies on PRM. This review also suggests other materials as potential PRM candidates, namely, Biomer® and IntramedicÔ polyethylene. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 467,477, 2001 [source] Bone reactions to longstanding functional load at implants: an experimental study in dogsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 9 2005T. Berglundh Abstract Objectives: The aims of the present investigation were (i) to study marginal bone level alterations following implant installation, abutment connection and functional loading and (ii) to analyse bone tissue reactions to functional load. Material and Methods: Six beagle dogs, about 1-year old, were used. All mandibular pre-molars were extracted. Three months later four implants of the Astra Tech Implants® Dental System were installed in one side of the mandible and four standard fixtures of the Brånemark System® were placed in the contralateral side of the mandible. Abutment connection was performed 3 months later and a plaque control programme was initiated. Three months after abutment connection fixed partial dentures (FPDs) made in gold were cemented to the maxillary canines and pre-molars. FPDs were also connected to the three posterior implants in each side of the mandible, while the mesial implant in each side was used as an unloaded control. Radiographs were obtained from all implant sites following implant installation, abutment connection and FPD placement. Ten months after the FPD placement the radiographic examination was repeated. The animals were sacrificed and biopsies from all implant sites were obtained and prepared for histological analysis. Results: The radiographic analysis revealed that largest amount of bone loss occurred following implant installation and abutment connection and that this loss was more pronounced at Brånemark than at Astra implants. The bone level alterations that were observed at implants exposed to 10 months of functional load in both implant systems were small and did not differ from control sites. The histological analysis revealed that implants exposed to functional load exhibited a higher degree of bone-to-implant contact than control implants in both implant systems. Conclusion: It is suggested that functional load at implants may enhance osseointegration and does not result in marginal bone loss. [source] Tissue reactions to sutures in the presence and absence of anti-infective therapyJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2005Knut N. Leknes Abstract Background: In the oral cavity, sutures are placed within tissues of high vascularity in a moist environment with infectious potential. The objective of this study was to evaluate tissue reactions at silk and expanded polytetrafluoroethylene (ePTFE) sutures in the presence and absence of anti-infective therapy (AT). Methods: Thirty-six sutures were placed within the mandibular keratinized gingiva in six Beagle dogs. Each animal received one braided silk (4-0) and one ePTFE (CV-5) suture in contra-lateral jaw quadrants at 14, 7, and 3 days prior to biopsy. Three animals received daily AT including topical 2% chlorhexidine solution and a systemic broad-spectrum antibiotic. Biopsy specimens allowed histometric analysis of tissue reactions along the central part of the suture loop including the area of perisutural epithelium, ratio inflammatory cells (ICs)/epithelial cells and IC/fibroblasts, and presence/absence of bacterial plaque in the suture track. Results: A perisutural epithelial sheath was forming within 3 days. The cross-sectional area of the epithelium increased with time for both suture materials (p=0.003) but was particularly pronounced for the silk sutures in the absence of AT. Clusters of IC were present in the perisutural connective tissue and epithelium. Over time, a more prominent increase in IC/fibroblasts was evident for the silk sutures in the absence of AT. The pooled material revealed a significantly higher IC/fibroblast ratio for silk compared with ePTFE sutures (p=0.017). Bacterial plaque influx was detected in 6/9 silk and 0/9 ePTFE suture channels in the presence, and 6/6 and 3/6 suture channels, respectively, in the absence of AT. Conclusions: AT may reduce biofilm formation and inflammation along the suture track. Braided silk, however, elicits more severe tissue reactions than ePTFE regardless of infection control. [source] Bone healing around implants placed in a jaw defect augmented with Bio-Oss®JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2000An experimental study in dogs Abstract The present experiment was carried out to study some tissue reactions around implants that were placed in an edentulous ridge which had been augmented with deproteinized natural bovine cancellous bone mineral. In 4 male beagle dogs, the premolars in the right side of the mandible were extracted and a large buccal ridge defect was created by mechanical means. The bone plate at the lingual aspect of the defect was left intact. 5 months later, the distal 2/3 of the defect area was augmented with Bio-Oss® (Geistlich Sons Ltd, Wolhusen, Switzerland) mixed with a fibrin sealer (Tisseel®, Immuno AG, Vienna, Austria). After 3 months of healing, 3 fixtures (Astra Tech AB, Mölndal, Sweden; TiO-blast; 8×3.5 mm) were installed in the mandible; 2 were placed in the augmented portion and 1 was placed in the non-augmented portion of the defect. After a healing period of 3 months, abutment connection was performed and a plaque control period initiated. 4 months later, the dogs were sacrificed and each implant region was dissected. The tissue samples were dehydrated, embedded in plastic, sectioned in the bucco-lingual plane and examined in the light microscope. It was observed that osseointegration failed to occur to implant surfaces within an alveolar ridge portion previously augmented with Bio-Oss®. In the augmented portion of the crest, the graft particles were separated from the host tissue as well as from the implant by a well-defined connective tissue capsule. Although the lingual aspect of all fixtures (test and control) was in contact with hard tissue at the time of installation, after 4 months of function, a deep vertical bone defect frequently had formed at the lingual surface of the implants. It was concluded that in this model (i) Bio-Oss® failed to integrate with the host bone tissue and (ii) no osseointegration occurred to the implants within the augmented portion of the crest. [source] Common carp tissue reactions to surgically implanted radio tags with external antennasJOURNAL OF FISH BIOLOGY, Issue 1 2007C. Bauer Examination of common carp Cyprinus carpio, carrying implanted telemetry transmitters, showed that wound healing was incomplete after 4 months and completed after 1 year. Granulation tissue, which encapsulated the transmitter, adhered to the intestine and liver. The liver was infiltrated by the granulation tissue after 1 year. Epidermal tissue grew down the channel for the antenna, establishing a potential pathway for pathogens. No signs of infections, however, were found. [source] Novel biopolymers as implant matrix for the delivery of ciprofloxacin: Biocompatibility, degradation, and in vitro antibiotic releaseJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 1 2007Suniket V. Fulzele Abstract The purpose of this study was to investigate the in vitro,in vivo degradation and tissue compatibility of three novel biopolymers viz. polymerized rosin (PR), glycerol ester of polymerized rosin (GPR) and pentaerythritol ester of polymerized rosin (PPR) and study their potential as implant matrix for the delivery of ciprofloxacin hydrochloride. Free films of polymers were used for in vitro degradation in PBS (pH 7.4) and in vivo in rat subcutaneous model. Sample weight loss, molecular weight decline, and morphological changes were analyzed after periodic intervals (30, 60, and 90 days) to monitor the degradation profile. Biocompatibility was evaluated by examination of the inflammatory tissue response to the implanted films on postoperative days 7, 14, 21, and 28. Furthermore, direct compression of dry blends of various polymer matrices with 20%, 30%, and 40% w/w drug loading was performed to investigate their potential for implant systems. The implants were characterized in terms of porosity and ciprofloxacin release. Biopolymer films showed slow rate of degradation, in vivo rate being faster on comparative basis. Heterogeneous bulk degradation was evident with the esterified products showing faster rates than PR. Morphologically all the films were stiff and intact with no significant difference in their appearance. The percent weight remaining in vivo was 90.70,±,6.2, 85.59,±,5.8, and 75.56,±,4.8 for PR, GPR, and PPR films respectively. Initial rapid drop in Mw was demonstrated with nearly 20.0% and 30.0% decline within 30 days followed by a steady decline to nearly 40.0% and 50.0% within 90 days following in vitro and in vivo degradation respectively. Biocompatibility demonstrated by acute and subacute tissue reactions showed minimal inflammatory reactions with prominent fibrous encapsulation and absence of necrosis demonstrating good tissue compatibility to the extent evaluated. All implants showed erosion and increase in porosity that affected the drug release. Increase in drug loading significantly altered the ciprofloxacin release in extended dissolution studies. PPR produced drug release >90% over a period of 90 days promising its utility in implant systems. The results demonstrated the utility of novel film forming biopolymers as implant matrix for controlled/sustained drug delivery with excellent biocompatibility characteristics. © 2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96:132,144, 2007 [source] Tissue reaction of the rabbit urinary bladder to tension-free vaginal tape and porcine small intestinal submucosaBJU INTERNATIONAL, Issue 6 2002D.M. Rabah Objectives ,To compare the histological tissue reactions of urinary bladder in close contact with polypropylene mesh tension-free vaginal tape (TVT) or porcine small intestinal submucosal (SIS) grafts, as the commercial availability of various materials has considerably simplified sling procedures for treating urinary incontinence, but erosion and infection after using artificial sling materials remain an important concern. Materials and methods ,Thirty female New Zealand rabbits were randomized to three groups, i.e. group A (TVT, 12 animals), group B (SIS, 12) and group C (surgical control, six). Through a laparotomy under anaesthesia and an aseptic technique, the bladder was approached at its dome, where a 0.5 × 1 cm piece of TVT or SIS was fixed in direct contact with the bladder wall. The control group underwent only bladder manipulation with no material applied. Half the animals in each group were killed after 6 weeks and the other half after 12 weeks. The urinary bladder was harvested and examined histologically. Results ,The grafts in both groups were characterized by dense foreign-body type reactions and were mostly attached loosely to the bladder wall by a thin layer of fibrovascular tissue. More importantly, the bladder wall reactions showed no inflammation in all 12 animals in group A (TVT) but three of them had various grades of fibrosis. There was severe transmural inflammation in one animal in group B (SIS); one rabbit had grade I and two had grade II fibrosis. The controls, as expected, showed no bladder wall reactions. Conclusion ,In this descriptive analysis of reaction types elicited on the urinary bladder by these grafts, both materials appeared to be safe. Although TVT elicited fewer and less severe adverse reactions, no statistical conclusions can be drawn. The clinical significance of these findings should emerge from long-term clinical data when they become available. [source] Influence of implant taper on the primary and secondary stability of osseointegrated titanium implantsCLINICAL ORAL IMPLANTS RESEARCH, Issue 4 2004Dominic O'Sullivan Abstract Objectives: The study presented was designed to analyse the mechanical performance and the primary and secondary stability characteristics of endosseous titanium implants with 1° (EXP1) and 2° (EXP2) of taper when compared with the standard Brånemark design (Nobel Biocare AB, Gothenburg, Sweden). Materials and methods: One pair of 10 mm EXP1 and control implants were placed in the femoral condyles of six rabbits. Paired 6 mm EXP1 and control implants and 6 mm EXP2 and control implants were placed in the tibial metaphysis. The control implants used were 4 mm diameter standard Brånemark implants, the same length as the test implants. At placement, insertion torque (IT) and resonance frequency analysis (RFA) measurements were performed. Six weeks postoperatively when the animals were killed, RFA and removal torque (RT) measurements were made. Results: At placement, significantly higher IT was needed to insert the EXP implants compared with the controls. RFA values were significantly higher for EXP1 implants placed in the tibia but not in the femur. In pooling data from the femur and tibia there was a significant difference. The EXP2 implants failed to insert fully and demonstrated a lower RFA value than may have been expected due to the exposed threads, although this difference was not statistically significant. Conclusions: The results from the present study showed that 1° of taper results in a better primary stability compared with the standard Brånemark design. There was no evidence that the tapered design caused negative bone tissue reactions. All the implants gained in stability during the healing period. Résumé L'étude présente a été effectuée pour analyser la performance mécanique et les caractéristiques de stabilité primaire et secondaire d'implants endoosseux en titane avec un taper (fuselé) 1° (EXP1) et 2 (EXP 2) comparés au modèle ad modum Branemark® standard. Une paire d'implants contrôles et un EXP1 de 10 mm ont été placés dans les condyles fémoraux de six lapins. Des paires d'implants contrôles et EXP1 de 6 mm et des implants contrôles et EXP2 de 6 mm ont été placés dans les métaphyses tibiales. Les implants contrôles utilisés avaient un diamètre standard de 4 mm, la même longueur que les implants tests. Lors du placement, des mesures de force d'insertion (IT) et d'analyse de fréquence de résonnance (RFA) ont été effectuées. Six semaines après l'opération lorsque les animaux ont été euthanasiés, les mesures RFA et les forces d'enlèvement (RT) ont été relevées. Lors du placement un IT significativement plus important a été nécessaire pour insérer les implants EXP1 comparé au contrôle. Les valeurs RFA étaient significativement plus importantes pour les implants EXP1 placés dans le tibia mais pas dans le fémur. En rassemblant les données du fémur et du tibia il y avait une différence significative. Les implants EXP2 ne parvenaient pas àêtre insérés à fond et ont montré une valeur RFA inférieure qui n'était pas inattendue vu les filetages exposés bien que ces différences n'étaient pas statistiquement significatives. Les résultats de l'étude présente ont montré que le taper 1 résultait en une stabilité primaire supérieure comparé au modèle ad modum Branemark® standard. Il n'y avait aucun signe que ce nouveau modèle causait des réactions tissulaires osseuses négatives. Tous les implants ont gagné en stabilité durant leur période de guérison. Zusammenfassung Ziele: Die hier vorgestellte Studie hatte zum Ziel, das mechanische Verhalten und die Charakteristika von Primär- und Sekundärstabilität bei enossalen Implantaten mit einer Gewindeneigung von 1° (EXP1) und von 2° (EXP2) zu untersuchen. Man verglich die Daten mit dem Standarddesign von Brånemark (Nobel Biocare AB, Gothenburg, Schweden). Material und Methode: Man implantierte ein Päärchen von 10mm-Implantaten (EXP1 und Kontrollimplantat) in die Femurkondylen von 6 Kaninchen. Zwei weitere Päärchen von 6mm-Implantaten (EXP1 und Kontrollimplantat, sowie EXP2 und Kontrollimplantat) implantierte man in die Metaphyse der Tibia. Bei den Kontrollimplantaten handelte es sich um Standardtypen von Brånemark mit einem Durchmesser von 4 Millimetern und derselben Länge wie die Testimplantate. Bei der Implantation mass man die Kraft, die es zu Eindrehen der Implantate brauchte (IT) und führte Messungen mit der Resonanzfrequenzanalyse (RFA) durch. Sechs Wochen nach der Operation wurden die Tiere geopfert, die RFA erneut durchgeführt und anschliessend der Ausdrehwiderstand (RT) bestimmt. Resultate: Bei der Implantation brauchte es signifikant grössere IT um die EXP-Implantate einzusetzen, als bei den Kontrollimplantaten. Die RFA-Werte waren bei den EXP1-Implantaten, die in die Tibia geschraubt worden waren, signifikant höher. Dies gilt aber nicht für die in den Femur geschraubten Implantate. Wurden die Daten vom Femur mit denen der Tibia verglichen, so erkannte man signifikante Unterschiede. Die EXP2-Implantate konnten nicht vollständig inseriert werden und zeigten auch tiefere RFA-Werte, als man den freiliegenden Schraubenwindungen entsprechend erwarten könnte. Diese Unterschiede waren aber nicht statistisch signifikant. Zusammenfassung: Die Resultate dieser Studie zeigten, das Schraubenwindungen mit 1° Steigung verglichen mit dem Standarddesign von Brånemark eine bessere Primärstabilität erzielten. Man fand andererseits keine Beweise, dass sich dieses neue Design der Schraubenwindungen negativ auf die Reaktion des Knochengewebes auswirkt. Alle Implantate gewannen während in der Heilphase an Stabilität dazu. Resumen Objetivos: El estudio presentado se diseñó para analizar el rendimiento mecánico y las características de estabilidad primaria y secundaria de implantes endoóseos de titanio con 1o (EXP1) y 2o (EXP 2) de autoroscado al compararlos con el diseño estándar de Brånemark (Nobel Biocare AB, Gothenburg, Suecia). Material y Métodos: Se colocó una pareja de implantes de 10 mm EXP1 y de control en los cóndilos femorales de 6 conejos. Se colocaron pareja de implantes de 6 mm EXP1 y de control y de 6 mm EXP2 y de control en la metáfisis tibial. Los implantes de control utilizados fueron Brånemark estándar de 4 mm de diámetro. A la colocación, se llevaron a cabo mediciones del torque de inserción (IT) y del análisis de la frecuencia de resonancia (RFA). Los animales se sacrificaron a las seis semanas de la operación, y se tomaron medidas del torque de remoción (RT). Resultados: Al colocarse, se necesitó un IT significativamente mas alto para insertar los implantes EXP en comparación con los de control. Los valores RFA fueron significativamente mas altos para implantes EXP1 colocados en la tibia pero no en el fémur. Confrontando los datos del fémur y de la tibia apareció una diferencia significativa. Los implantes EXP2 fracasaron en insertarse completamente y demostraron un menor valor de RFA del que se podía esperar debido a la exposición de las roscas, aunque esta diferencia no fue estadísticamente significativa. Conclusiones: Los resultados del presente estudio mostraron que 1o de autoroscado resultan en una mejor estabilidad primaria comparada con el diseño estándar de Brånemark. No hubo evidencia de que el diseño de autoroscado causara reacciones negativas en el tejido óseo. Todos los implantes ganaron estabilidad durante el periodo de cicatrización. [source] | |||||||||||||