bluuebunny/crossref_metadata_2025_split huggingface dataset:
Orientation of gingival fibroblasts and newly‐synthesized collagen fibers in vitro
Authors: Pitaru S. , Melcher A. H. 
Published: July 2006

One hundred and fourteen pairs of transversally cut root sections ∼150 μm thick were obtained from porcine premolars and were attached to the floor of 35 mm culture dishes leaving an interdental space (IDS) of ∼500 μm between their cemental surfaces. Following partial demineralization of half of the samples, human gingival fibroblasts (HGF) were seeded in each dish and supplemented daily with 50μg/ml of vitamin C. The cultures were observed daily using phase microscopy. Demineralized and non‐demineralized specimens were obtained at each of 12 h, 24 h, 5, 10, 20, and 30 days, stained with van Gieson's picro‐fuchsin for identification of collagen or processed for examination by scanning electron microscopy (SEM). Two of the 30‐day‐old cultures were processed for examination by transmission electron microscopy.Sheets of oriented cells anchored to the cemental surfaces of the root sections and the floor of the dish were evident at 5 days. After 10 days of culture, a multilayered bridge‐like structure of oriented cells and fibrils (50–100 nm thick) was seen to connect the opposing cemental surfaces bordering the IDS at one or more sites. Oriented fine fibrillar structures were observed at this time using van Gieson's staining. The IDS was completely filled with oriented cells and fibers after 20 days of culture. Similar structures extending between the cemental surfaces and the floor of the dish developed around the rest of the circumference of the root sections. The appearance of this material at 30 days as observed by van Gieson's staining was reminiscent of transseptal and dento‐gingival fibers in vivo. The staining by van Gieson's method, the size of the fibrils, and the banded fibrils observed by TEM in cultures 30 days old suggest that the fibrillar material was predominantly collagen.The system was significantly more reproducible when demineralized rather than mineralized sections of root were used. It is suggested that attachment, migration, and contraction of the HGF are crucial for the orientation of the cellular and endogeneously produced fibrillar components in vitro and that these processes may operate in the development and healing of oriented fiber systems in vivo. Further, partial demineralization may facilitate these processes in wound healing.
Metabolic change in cultured gingival fibroblasts exposed to bacterial extracts
Authors: Larjava Hannu 
Published: July 2006

Hyaluronic acid synthesis was studied in human gingival fibroblast cultures exposed to bacterial extracts from dental plaque, Bacillus cereus, and Escherichia coli (lipopolysaccharide, LPS). Dental plaque extract was the best stimulant of hyaluronic acid synthesis. B. cereus extract was almost as effective, but the effect of LPS was insubstantial. This indicates that gram‐positive microorganisms of dental plaque, as well as gram‐negative bacteria, may be involved in the stimulation of hyaluronic acid synthesis in gingival fibroblasts.The effect of indomethacin, cortisol, and cycloheximide on hyaluronic acid synthesis were studied in control and plaque extract treated cultures. Indomethacin had no effect whereas cortisol inhibited the synthesis both in control and treated cultures. Cycloheximide prevented the stimulation of hyaluronic acid synthesis in treated cultures. This suggests that protein synthesis is required for the stimulation of hyaluronic acid synthesis in the presence of plaque extract. The altered metabolism of connective tissue cells due to dental plaque may be important in the development of periodontal disease.
Morphological studies on periodontal disease in the cynomolgus monkey
Authors: Brecx M. C. , Nalbandian J. , Ooya K. , Kornman K. S. , Robertson P. B. 
Published: July 2006

Histological observations were made on ligature‐induced periodontitis in two adult female monkeys (Macaca fascicularis). Silk ligatures were placed around posterior teeth and the shift from gingivitis to periodontitis was followed radiographically and bacteriologically for eight and nine weeks, respectively. Fifteen tissue blocks with ligatures in situ were obtained. Following decalcification with EDTA and epon embedding, sections one micron in thickness were prepared in the mesio‐distal plane to study the interproximal regions. Two additional blocks were processed for routine histology.Radiographically, progressive bone loss was observed in the interproximal regions that had a ligated tooth surface. Histologically, prominent features included supragingival and subgingival plaque (with dense accumulations of bacteria around and within the ligature), apical migration of the junctional epithelium, loss of collagen and connective tissue attachment, and osteoclastic bone resorption. A chronic inflammatory reaction was evidenced by a dense infiltration of leukocytes in the connective tissue, with a high proportion of plasma cells. Numerous polymorphonuclear leukocytes were seen in pathways between epithelial cells and in a zone around the plaque‐laden ligature. These morphological observations, similar to descriptions of human periodontitis, lend support for the usefulness of this model in the study of human periodontitis.
Connective tissue attachment formation following exclusion of gingival connective tissue and epithelium during healing
Authors: Magnusson Ingvar , Nyman Sture , Karring Thorkild , Egelberg Jan 
Published: July 2006

The present investigation was designed to evaluate the potential for reformation of connective tissue attachment on exposed and planed root surfaces by preventing the dentogingival epithelium and the gingival connective tissue from interfering with healing following periodontal surgery.Following the elevation of soft tissue flaps, the buccal and proximal alveolar bone of 24 teeth (48 roots) was removed to mid‐root level in 6 monkeys and the exposed root surfaces were carefully planed in order to remove the root cementum. Before the flaps were repositioned and sutured, a membrane (Millipore® filter) was placed over the denuded part of the root surfaces of 16 teeth (test teeth) in order to prevent the epithelium and the gingival connective tissue from interfering with healing. The membrane was adjusted to cover the tooth surfaces from midcrown level to approximately l mm apical to the bone crest. No membranes were placed around the remaining 8 teeth (control teeth) before flap repositioning. The animals were sacrificed 6 months after surgery. The jaws were removed and histological sections of test and control teeth including their buccal periodontal tissues were produced. Nine of the test teeth had to be excluded from examination due to technical failures in the surgical procedure or tissue preparation.New cementum with inserting collagen fibers was observed on all remaining 14 test roots. The length of this newly formed fibrous attachment corresponded to approximately 50% of the distance from the apical extension of root planing to the cemento‐enamel junction. In the majority of the control teeth no new attachment had formed but a “long” junctional epithelium was lining the root surfaces to the apical extension of root planing. In 3 control roots a small amount of new cementum with inserting collagen fibers was found in the most apical area of root planing.The results showed that the reformation of a connective tissue attachment was considerably favored by the placement of membranes which prevented the dentogingival epithelium and the gingival connective tissue from interfering with healing.
Gas‐liquid chromatography of the gingival fluid as an aid in periodontal diagnosis
Authors: Botta G. A. , Radin L. , Costa A. , Schito G. , Blasi G. 
Published: July 2006

There is increasing evidence that rod‐shaped Gram negative anaerobic bacteria, as those belonging to black‐pigmented Bacteroides, may play a role in the pathogenesis of periodontal diseases. Anaerobic bacteria are known to produce, as end‐products of their metabolism, several volatile fatty acids, whose detection in clinical specimens by direct gas liquid chromatography (GLC) has been usefully utilized to demonstrate their presence in the infected site. The results obtained analyzing by GLC the gingival fluid collected from patients suffering from periodontal diseases are reported here. A good statistical correlation of the GLC profile has been found with the gingival index and the colonization by gram‐negative bacteria at each selected site.The data obtained strongly suggest that butyric acid may be considered a reliable marker of the severity of the disease, and its quantitative changes may be useful in following the clinical course of the process. The data correlate well with the biological activities of butyric acid, which have been reported to be abundant in plaque and to exert a cytotoxic activity on a variety of cells including gingival fibroblasts.No correlation has been found between gingival fluid flow rate and fatty acids profile in GLC. It can be concluded that GLC measures the overall metabolic activity of the bacterial population colonizing the subgingival area, while the rate of gingival fluid flow reflects the degree of the inflammatory response of the host. The combined use of the two laboratory tests should provide the clinician with more quantitative and reproducible parameters for monitoring the disease activity.
Cytochemical identification of lysosomal system of the rat junctional epithelium
Authors: Yamasaki Akira , Nikai Hiromasa , Ijuhin Naokuni , Takata Takashi , Ito Hiroshi 
Published: July 2006

Structures taking part in the lysosomal system of rat junctional epithelium (JE) were evaluated by means of ultrastructural enzyme cytochemistry. Acid phosphatase (AcPase) and trimetaphosphatase (TMPase), both the representative lysosomal marker enzymes, were frequently detected in dense bodies which contained the homogeneous matrix and showed pleomorphic appearance. These activities were also often localized to the phagosomes with heterogeneous contents, the reaction of TMPase being much more intense than that of AcPase. Cisternal structures, most probably corresponding to GERL, also displayed AcPase activity and exhibited the close morphologic relationships with lysosomal structures. On the other hand, the localization of thiamine pyrophosphatase activity was almost limited to the innermost cisterna of the Golgi complex. Neither AcPase nor TMPase activity could be detected in the cytoplasmic vacuoles, which were characteristically numerous in rat JE and the multivesicular bodies.From the present findings, it is suggested that the lysosomal system in rat JE is composed of dense bodies (primary lysosomes), phagolysosomes (secondary lysosomes), and GERL and that some of those lysosomes are apparently derived from GERL. Different localization patterns of marker enzymes examined might reflect the enzymatic heterogeneity of various lysosomal elements.
Gingival blood flow measured with a laser Doppler flowmeter
Authors: Baab David A. , ÖBerg P. Ake , Holloway G. Allen 
Published: July 2006

Previous studies of gingival blood flow have used techniques that were discrete, invasive, or only applicable to animals. The present study assessed this parameter in 10 healthy humans using a noninvasive laser Doppler flowmeter (LDF), Blood flow rate was determined in the interdental papillae. Free and attached gingival, and alveolar mucosa, Measurements were made continoulsy at four sites per patient and discontinoulsy at 21 sites per arch representing the four locations. The effects of heat, cold, pressure, and occlusal force on blood flow were measured.Blood flow wave patterns differed consistently by tissue type, Mean blood flow was singnifiantly hinger (p < 0.001) in alveolar mucosa than in the gingival. Both heat and cold produced initial hyperemia, followed by a rapid return toward baseline. Localized pressure caused ischemia followed by reactive hyperemia in all tissue types, Transient ischemia was seen during occlusal force at the free gingival margin of test teeth, but blood flow in adjacent interdental papillae and attached gingival remained unaltered. A significant difference (p < 0.001). The LDF offeres promise as a noninvasive method to study gingival blood flow.
Morphological studies on periodontal disease in the cynomolgus monkey
Authors: Brecx M. C. , Nalbandian J. , Kornman K. S. , Robertson P. B. 
Published: July 2006

Electron microscopic observations were made on naturally occurring gingivitis, on gingivitis at non‐ligated sites of an experimental animal, and on ligature‐induced periodontitis in a periodontal disease model using female cynomolgus monkeys.For both types of gingivitis specimens, a plaque associated chronic inflammatory reaction was observed, comparable to that described for the human established lesion. Bacterial accumulations on tooth surfaces were separated from the epithelium by neutrophils which exhibited variations in fine structure and extent of bacterial phagocytosis related to their proximity to the plaque. In the inflamed connective tissue of the papillae, collagen was reduced to strands extending between the cellular elements. The plasma cell was the most common inflammatory cell and had three major variations in form.With ligature‐induced periodontitis, similar inflammatory features were observed in the gingiva. A complex flora like that encountered in human periodontitis was observed around and within the ligature as well as more apically in the pocket. As compared to the flora in gingivitis, more spirochetes were encountered, a larger proportion of the microorganisms appeared to be in a living state, and bacteria were in contact with the epithelial surface, rather than being walled off by the neutrophils. This seemingly more aggressive plaque was associated with an advanced lesion characterized by changes that indicated sequential destruction of the collagenous attachment to cementum and concommitant apical migration of the epithelial attachment. No bacteria were observed in the soft tissues, even in the wide intercellular spaces between the epithelial cells.
Effect of chlorhexidine gluconate mouthrinse on plaque bacteria
Authors: Briner W. W. , Grossman E. , Buckner R. Y. , Rebitski G. F. , Sox T. E. , Setser R. E. , Ebert M. L. 
Published: July 2006

The antimicrobial effect of a 0.12% chlorhexidine gluconate mouthrinse on plaque bacteria was compared to that of a placebo mouthrinse without chlorhexidine gluconate. Forty subjects in each treatment group rinsed twice daily with 15 ml mouthwash for six months. They were instructed to continue their usual oral hygiene practices. After six months, the subjects stopped using the mouthrinse. Supragingival plaque was collected from each subject and assayed for eight representative microbial populations at baseline, after three and six months of treatment, and after a three‐month post‐treatment period.During the six months of mouthrinse use, significant reductions in the numbers of total aerobes. total anaerobes, streptococci, and actinomyces were observed in plaque samples taken from subjects using the chlorhexidine mouthrinse. The effect of chlorhexidine on actinomyces accumulation was especially pronounced with reductions ranging from 85–97%. This was considered to be particularly significant since actinomyces is one of the bacteria known to be periodontopathic in both experimental animals and in humans. Although chlorhexidine treatment reduced the number of microbes on teeth, it did not produce a detectable shift in microbial populations.At the end of the three‐month post‐treatment period, the microbial profile was similar to the pre‐treatment profile for both groups. Therefore, no residual effects of chlorhexidine on plaque bacteria were observed after cessation of rinsing.
Clinical trials in periodontal therapy
Authors: Lindhe Jan , Nyman Stare 
Published: July 2006

The success of periodontal therapy is evaluated not only after the termination of the comparatively short active treatment phase, but also at regular intervals during the extended maintenance phase. The main objectives of the active treatment include: (1) elimination of the inflammatory lesions present in the periodontium (2) reduction of probing pocket depth and (3) improvement of attachment levels, while the aim of the maintenance phase of therapy is the prevention of disease recurrence.Elimination of the inflammatory lesions in the periodontium is accomplished by meticulous plaque and calculus removal performed either as a single measure or combined with one of several different surgical treatment modalities. Findings from clinical trials have demonstrated that it is not the technique ‐ nonsurgical‐surgical ‐ used during basic therapy, but the degree of root debridement accomplished that seems to be the determining factor for success in terms of resolution of periodontitis. Furcation involved premolars/molars constitute a problem with respect to effectiveness of therapy. Reliable research data describing treatment effects in the furcation regions of multirooted teeth are scarce. As a result of the elimination of the inflammatory lesions the periodontal tissues will offer more resistance to probing. This is clinically identified as probing pocket depth reduction, attachment level imrpovements and recession of the marginal gingiva. Research findings reveal that surgical and nonsurgical methods are almost equally effective in these respects. The concept that surgical methods which include resective measures will cause more gingival recession than non‐resective measures should be questioned.Long‐term clinical trials have demonstrated that patients who, following active treatment, are enrolled in carefully supervised plaque control programs only occasionally show signs of disease recurrence, while in this respect non‐monitored patients frequently display signs of recurrent disease. It is suggested that the long‐term effect of periodontal therapy is more related to the quality of the maintenance care program than the techniques utilized during active therapy.
Polyamines found in gingival fluid enhance the secretory and oxidative function of human polymorphonuclear leukocytes in vitro
Authors: Walters J.D. , Chapman K.J. 
Published: July 2006

SummaryMany bacterial and host cells contain large amounts of polyamines that can be released at infection sites as a result of cell lysis. Consequently, the putrescine and spermidine content of gingival fluid from inflamed periodontal pockets (0.1 to 1 mM) is sharply elevated in comparison to peripheral blood. At these levels, polyamines potentiated fMet‐Leu‐Phe‐induced Ca2+ signaling in polymorphonuclear leukocytes (PMNs) in vitro. Consistent with the essential role of Ca2+ signaling in PMN activation, secondary granule release and superoxide anion production by fMet‐Leu‐Phe‐stimulated PMNs was enhanced in the presence of polyamines. Thus, polyamines may play a local role in modulating the antimicrobial activity of PMNs in periodontal disease.
Detection of antigenic proteins in Porphyromonas gingivalis using two‐dimensional electrophoresis and western blots
Authors: Tani M. , Yamada T. , Kato I. 
Published: July 2006

SummaryUsing two‐dimensional (2D) electrophoresis and western blot assay, we analyzed antigenic proteins in Porphyromonas gingivalis uniquely recognized by antibodies in sera of periodontitis subjects. Proteins in the total membrane fraction of P. gingivalis 381 were resolved into at least 70 protein spots by 2D electrophoresis. In the gel stained with silver, the substance around 47 kDa protein on the acidic side (at an isoelectric point of about 4.5) was stained as a smear. Antigenic substances were characterized using purified IgGs from sera of 16 adult periodontitis (AP), 19 rapidly progressive periodontitis (RPP) and 14 periodontally healthy volunteers. Western blots demonstrated that 75 kDa protein reacted with IgGs from 75% of AP patients (p>0.001), the antigenic substance around acidic 47 kDa protein reacted with IgGs from 81.3% of AP (p>0.01) and 68.4% of RPP patients (p>0.01) and the acidic 47 kDa protein reacted with 87.5% of AP (p>0.01) and 78.9% of RPP patients (p>0.01). The reaction frequency was significantly different from that of the healthy volunteers. Also 51 kDa and 41 kDa proteins reacted with 47 and 43 of 49 IgG samples, respectively. The substance around acidic 47 kDa protein reacted with mouse antiserum to P. gingivalis‐LPS. After treatment with pronase or heat, the antigenic reactions disappeared not only from the proteins, but also from the area around the acidic 47 kDa protein. When the fraction was digested with lipase, the antigenic reaction of the area decreased. It appeared that the acidic 47 kDa protein and the LPS around it formed a complex, and that the LPS contained the lipid portion. These results suggested that the acidic 47 kDa protein can be classified among the lipid A‐associated proteins, and that it is the major antigenic protein which is recognized by antibodies in sera of almost periodontal patients in P. gingivalis 381.
Relationship between oral pain and ethanol concentration in mouthrinses
Authors: Bolanowski S.J. , Gescheider G.A. , Sutton S.V.W. 
Published: July 2006

SummaryPrevious reports have indicated that certain mouthrinses, even when used as directed can induce oral pain. In order to help determine the causal agent(s), various commercially available mouthrinses, as well as control solutions, were tested in a psychophysical study in which subjects rated categories of pain during and after mouthrinsing. More specifically, the studies tested the effects of ethanol concentration on induced pain. The results show that there is a direct relationship between ethanol content and the amount of induced pain. Furthermore, the amount of pain was found to increase with time of rinsing, and to slowly decrease after cessation of rinsing. Lastly, comparison of ethanol/water controls with a marketed product (Clear Choice®) matched for ethanol content showed that, while ethanol was the key factor in mouthwash‐induced oral pain, other presently unidentified agents can also add to the effect.
Stimulation of human periodontal ligament fibroblast collagenase production by a gingival epithelial cell‐derived factor
Authors: Ohshima M. , Taguchi M. , Ogoshi T. , Fujikawa K. , Lto K. , Otsuka K. 
Published: July 2006

SummaryTo examine whether cell‐to‐cell interactions between human gingival epithelial cells (HGE) and periodontal ligament fibroblasts (PLF) or gingival fibroblasts (GF) take place in the periodontium, the effects on collagenase production by PLF and GF were analyzed after adding several concentrations of HGE‐con‐ditioned medium (HGE‐CM) to PLF or GF culture. Collagenase production by both cell populations was stimulated by adding HGE‐CM, which stimulated collagenase production by PLF to a greater extent than that by GF. The HGE‐derived stimulatory factor had a molecular mass of approximately 20 kDa, and its stimulant effect was inhibited markedly in the presence of an anti‐human interleukin‐lα (IL‐lα) neutralizing antibody, indicating that the factor was identical to, or antigenically cross‐reactive with, IL‐lα. These results suggest that epithelial apical migration in the periodontium may occur after interstitial resident cells have released tissue‐degrading enzymes, such as collagenase, and damaged the extracellular matrix, once a sufficient amount of IL‐lα‐like factor for stimulating the production of proteolytic enzyme has been released by HGE in periodontal lesions.