bluuebunny/crossref_metadata_2025 huggingface dataset:
Extracellular matrix analysis of nifedipine‐induced gingival overgrowth: immunohistochemical distribution
Authors: Romanos G. E. , Schröter‐Kermani C. , Hinz N. , Herrmann D. , Strub J. R. , Bernimoulin J.P.
Published: July 2006

The purpose of this study was to demonstrate the localization of collagen types I, III, IV, V, VI and VII as well as the glycoprotein fibronectin in nifedipine‐induced gingival overgrowth. The slices, after the use of indirect immunofluorescence (incubation with antibodies against these extracellular matrix components), showed a diffuse distribution with the anit‐types I and III in the stroma and fluorescent staining of the basement membranes of the epithelium, blood vessels and nerves with collagen type IV antibodies. The increased number of vessels was localized near the surface of the lesion. Collagen tyep V ‐ seen as a filamentous ‐ and collagen type VI ‐ as microfibrillar ‐ components were also localized in the tissue, showing completely different patterns of distribution. Collagen type V appeared “crater”‐like and type VI displayed a “honeycomb”‐shaped structural model. The blood vessels were not stained but the area around their walls demonstrated an intense fluorescence with these antibodies. Collagen type VII showed a characteristic linear staining near to the epithelial basement membrance. In contrast to this, fibronectin localized with a varied intensity in the different areas of the tissues and presented a “could”‐like structure. This shows differences between the matrix components in nifedipine‐induced hyperplasia and confirms the heterogeneity of the matrix in health and in gingival alterations.
ELISA detection of glycosaminoglycan (GAG)‐linked proteoglycans in gingival crevicular fluid
Authors: Shibutani T. , Nishino W. , Shiraki M. , Iwayama Y.
Published: July 2006

The purpose of this study was to develop an ELISA method to detect chondroitin sulfate isomer‐linked proteoglycans in gingival crevicular fluid (GCF), and to lelucidate the role played by the glycosaminoglycans (GAGs) in GCF during experimentally‐induced periodontitis in dogs. Experimental periodontitis was induced by placement of a silk ligature below the gingival margin of the molar teeth in 3 mongrel dogs. GCF was collected using microcapillary tubes at 0. 7.21 and 60 days after ligature placement. Too compare with GAG in GCF, bovinenasal cartilage proteoglycan monomer, dog's serum and supernatant of homogenized gingival tissuw were prepared. Combination of monoclonal antibodies, 3B3 and 9A2, and specific enzymatic digestion made possible the indentification of chondroitin 4 sulfate (C4S), chondroitin 6 sulfate (C6S) and dermatan sulfate (DS). The ELISA method detected very small amounts of chondroitin sulfate (CS) isomers (15‐1000 ng/ml of bovine nasal cartilage proteoglycan). The ELISA value of CS isomers in GCF was lower than that of homogenized gingival tissue but higher than that of the serum. The ELISA value of C4S, C6S and DS, although fluctuating, increased in proportion to the severity of the inflammation.
Inhibition of the formation of oral calcium phosphate precipitates: beneficial effects of Chinese traditional (Kampo) medicines
Authors: Hidaka Saburo , Abe Kimio , Takeuchi Yoshio , Liu Sheng‐Yan
Published: July 2006

Screening tests on the formation of calcium phosphate precipitates using 23 different kinds of Kampo medicines (Chinese traditional medicines) were carried out, at concentrations where the effects of chelation are not significant. Four of them, Hochu‐ekki‐to (TJ‐41), Kyuki‐kyogai‐to (TJ‐77), Oren‐to (TJ‐120) and Inchin‐ko‐to (TJ‐135) showed an inhibitory effect on the formation of amorphous calcium phosphate (ACP). The inhibitory effect on the induction time and the rate of transformation to hydroxyapatite (HAP) varied greatly among the 23 Kampo medicines. We classified them according to their effects on increasing the induction time and/or decreasing the rate of HAP transformation. Ethane‐1‐hydroxy‐1, 1‐diphosphonate (EHDP) was used as the standard. This compound is a common toothpaste additive which decreases dental calculus formation. Two of the 23 Kampo medicines showed little or no inhibition either on the induction time or on the rate of HAP transformation. Twelve of them reduced the rate of HAP transformation by 20‐40% and with 1.9‐ to 4.0‐fold increases in the induction time. The remaining nine showed even greater activity. Keishi‐ninjin‐to (TJ‐82), Dai‐kenchu‐to (TJ‐100), Toki‐to (TJ‐102), Rikko‐san (TJ‐110) and San'o‐shashin‐to (TJ‐113) showed the same inhibitory effect as EHDP. Shigyaku‐san (TJ‐35;5.2‐fold), Dai‐kanzo‐to (TJ‐84;4.9‐fold), Oren‐gedoku‐to (TJ‐15:12.7‐fold) and Inchin‐ko‐to (TJ‐135;9.5‐fold) had a greater effect on the increase of induction time than EHDP and reduced the rate of HAP transformation by 50‐60%. These results suggest that these nine kinds of Kampo medicines may have potential as anticalculus agents in toothpastes and mouthwashes.
Multinucleated fibroblastic cells in the periodontal ligaments of aged rats
Authors: Sasaki Takahsia , Garant Philias R.
Published: July 2006

Using 12‐ to 18‐month ‐old rats, we examined the ultrastructural and cytochemical features of multinucleated fibroblastic cells (MFCs) in the periodontal ligament (PDL) of molars. In aged rats, the MFCs were distributed randomly in the PDL and exhibted cytoplasmic structural variations which were not dependent on the number of nuclei. There was a tendency for the MFCs to cluster in the PDL. The MFCs, rich in cytoplasmic organelles involved with procollagen synthesis such a rought endoplasmic reticulum and the Golgi apparatus, incorporated and secreated 3H‐prolince‐labled products. The MFcs also possessed many phagosomes containing intact collagen fibrils.n These MFCs were apparently involved in phagocytosis and intracellular degradation of incorporated collagen fibrils. Phagosome‐rich MFCs contain acid phosphatase activity in primary and secondary lysosomes, similar ro stronger in intensity to that which can be demonstrated in mononuclear fibroblasts. However, unlike mononuclear fibroblasts, the MFcs did not exhibit alkaline phosphatase acitivity along their plasma membranes. These results suggest that MFcs demonstrate a range of fibroblastic cellular activity, including collagen phagocytosis, and that they may lack certain plasma membrane glycoproteins, which might explain the occurrence of multinucleation in these cells.
Interactions of chlorhexidine with salivary films adsorbed at solid/liquid and air/liquid interfaces
Authors: Freitas L. B. , Vassilakos N. , Arnebrant T.
Published: July 2006

Chlorhexidine is a cationic compound which has been shown to bind to salivary proteins and enamel through electrostatic interactions. The aims of this study were to investigate the interaction of chlorhexidine molecules with salivary films absorbed on solid surfaces with varying physico‐chemical characteristics and to investigate the effect of different concentrations of chlorhexidine on the surface tension of saliva. The interactions between 0.2% chlorhexidine digluconate with films adsorbed from whole saliva were monitored by a Rudolph Thin‐film ellipsometer equipped with a He‐Ne laser (632.8 nm). The films were adsorbed on hydrophilic silica surfaces which were plasma cleaned or on methylated hydrophobic surfaces. Experiments of chlorhexidine adsorption on bare surfaces were also performed. The surface tension of mixtures of whole saliva with various concentrations of (0.1%, 0.2%, 1%) chlorhexidine was monitored with a tensiometer. The results show that chlorhexidine adsorbs on both types of studied substrates. Addition of the substance followed by rinsing caused a partial desorption of the adsorbed pellicles. Furthermore, at all studied concentrations chlorhexidine reduced the interfacial tension. There are indications that the amphiphilic characteristics of the molecule play an important role in the retention of the substance in the oral cavity.
High‐titer antisera from patients with periodontal disease inhibit bacterial capsule‐induced bone breakdown
Authors: Meghji S. , Henderson B. , Wilson M.
Published: July 2006

Solubilized surface‐associated material (SAM) form a number of periodonotopathogenic bacteria have been shown to be potent stimulators of bone resorption in vitro in the murine calvarial bone culture assay. Antibodies to the constituents of SAM are also found in patients with periodontal disease. Serum from patients with severe generalized periodontitis (SGP) containing high titers of antibodies to the SAM of Porphyromonas gingivalis completely inhibited the bone resorption induced by SAM from this organism. In contrast, serum from patients with low titers of antibodies to SAM form P. gingivalis failed to inhibit bone resorption. High‐titer sera (containing antibodies to SAM from Actinobacillus actinomycetemcomitans) from patients with localized juvenile periodontitis (LJP) were added to calvarial cultures stimulated with SAM from A. actinomycetemcomitans. Of 6 high‐titer sera tested, only 4 inhibited bone breakdown, the other 2 sera having no effect on resorption. Low‐titer sera were also ineffective at blocking bone resorption. This suggests that the antibody response to SAM may have a protective effect in patients with periodontal disease.
Role of substance P (SP) in development of symptoms of neurogenic inflammation in the oral mucosa of the rat
Authors: Györfi A. , Fazekas Á. , Irmes F. , Jakab G. , Sütö T. , Rosivall L.
Published: July 2006

In the present series of investigations we first studied the local effects of exogenous substance P (SP) on the hallmarks of neurogenic inflammation, i.e. vascular permeability and blood flow, in the oral mucosa of the rat. Pretreatment with capsaicin was shown to attenuate the symptoms of neurogenic inflammation; therefore, the distribution of nerve fibers displaying substance P‐like immunoreactivity (SP‐IR) in the mandibular mucosa was also assessed in control rats and in animals pretreated with capsaicin both neonatally and in adulthood using immunohistochemical techniques. The application of SP at a dose of 7.5 nmol resulted in an almost 70% increase of vascular permeability (NS) and the administration of a four‐fold higher dose (30 nmol) produced about 150% increase in Evans blue extravasation compared with control values (p<0.05). A similar increase (ca 146%) in vascular permeability was observed in response to 45 nmol SP solution (p<0.05). While the 7.5 nmol SP‐solution failed to affect blood flow, the 30 nmol SP significantly increased it by ca. 38% (p<0.05). The administration of the 45 nmol SP solution resulted in a similar enhancement of blood flow (43%, p<0.05). Capsaicin pretreatment performed either neonatally or in adulthood has reduced the number of SP‐immunoreactive fibers in the oral mucosa. Our functional results suggest that SP may have a role in the experimentally‐induced neurogenic inflamation of the oral mucosa in the rat. This is also supported by our finding that capsaicin pretreatment, known to decrease the number of SP‐immunoreactive fibers in these tissues, reduced the symptoms of neurogenic inflammation.
Lethal photosensitization of bacteria in subgingival plaque from patients with chronic periodontitis
Authors: Sarkar S. , Wilson M.
Published: July 2006

Subgingival plaque samples from patients with chronic periodontitis were exposed to light from a 7.3 mW Helium/Neon laser for 30 s in the presence and absence of 50 μg/ml toluidine blue O as a photosensitizer. Viable counts of various groups and species of bacteria were carried out before and after irradiation. The median numbers of viable bacteria initially present in the 30‐μl aliquots irradiated were 1.13 × 105 cfu (aerobes), 4.08 × 105 cfu (anaerobes), 4.92 × 103 cfu (black‐pigmented anaerobes), 4.75 × 102 cfu (Porphyromonas gingivalis), 6.15 × 103 cfu (Fusobacterium nucleatum) and 1.7 × 104 cfu (streptococci). The dye/laser combination achieved significant reductions in the viability of these organisms, the median reductions in the viable counts being 91.1% for aerobes, 96.6% for anaerobes, 100% for black‐pigmented anaerobes, P. gingivalis and F. nucleatum and 94.2% for streptococci. Overall, the viability of bacteria in the 20 plaque samples was not significantly decreased by the dye alone. However, in a small minority of samples there were indications of light‐independent, dye‐induced toxicity. Low‐power lasers, in conjunction with appropriate photosensitizers, may be a useful adjunct to mechanical debridement in the treatment of inflammatory periodontal diseases if a similar effectiveness against subgingival plaque bacteria can be achieved in vivo.
Reliability of filter‐strip sampling of gingival crevicular fluid for volume determination using the Periotron
Authors: Stewart James E. , Christenson Peter D. , Maeder Linda A. , Palmer Mary A.
Published: July 2006

This study explored gingival crevicular fluid (GCF) volumes as measured by the Periotron in an attempt to find a more objective measure of gingival inflammation that could be used in dental compliance studies. The first step in this process was to assess the realiability of the method of collecting and determining GCF volumes as described by the manufacturer. Collections of GCF from both the buccal and lingual surfaces of 6 teeth from 18 subjects with good to moderate plaque accumulation was accomplished. At a later time these same surfaces were retested for a comparison with the initial value for reliability determination. We found that only 23% of the tooth surface pairs varied by less than 20% and 57% of these pairs differed by at least 50%. These values were similar for both good and moderate plaque accumulation subjects. In these subjects, reliability measurements at individual tooth surfaces did not approach acceptable levels of reliability. However, when the GCF values from the 12 tooth surfaces were averaged for each subject, differences between the two measurements improved markedly. Sixty‐one percent of these subject pairs differed by less than 20%. Therefore, the average GCF value from subjects with good to moderate plaque accumulations may be compared with reasonable accuracy.
Immunohistological analysis of memory T lymphocytes and activated B lymphocytes in tissues with periodontal disease
Authors: Yamazaki Kazuhisa , Nakajima Takako , Aoyagi Toshihiko , Hara Kohji
Published: July 2006

Memory T‐cells and activated B‐cells were identified in cryostat sections of adult periodontitis (AP) lesions and categorized in terms of frequency and distribution. Nineteen periodontitis biopsies were obtained at the time of periodontal surgery to remove residual periodontal pockets following the completion of initial preparation. Gingival tissues exhibited various degree of inflammation (Gl of 0‐2) but probing depths of < 4 mm and < 5 mm loss of attachment. As a control, 5 gingivitis specimens (Gl of 1, probing depth and loss of attachment of ≤ 3 mm) were obtained from premolar and third molar sites requiring extraction for either orthodontic treatment or pericoronitis. Serial cryostat sections (6 μm in thickness) were prepared from each biopsy, on which a double staining avidin‐biotin immunoperoxidase and avidin‐biotin alkaline phosphatase technique was used to identify CD4+, CD45RO+ memory T‐cells and activated CD19+ B‐cells expressing CD23 or CD25. In periodontitis lesions the mean percentage of CD4+ cells expressing CD45RO was consistently high (65.9% in the crevicular (C) one‐third (1/3), 61.2% in the middle (M) 1/3 and 62.5% in the oral (O) 1/3). This contrasts with the low mean percentage of CD4+, CD45RA+ naive T‐cells (17.1% in the C 1/3, 14.8% in the M 1/3 and 12.4% in the O 1/3). In gingivitis specimens, the incidence of CD4+, CD45RO+ was 81.9% in the C 1/3, 81.1% in the M 1/3 and 89.0% in the O 1/3. This was higher than that of periodontitis biopsies. With CD4+, CD45RA+ the incidence was 10.0% in the C 1/3, 8.0% in the M 1/3, and 6.6% in the O 1/3 and the relationship to the periodontitis biopsies was reversed. However, the percentage of CD23+ and CD25+, CD19+ B‐cells which were identified in 13 out of 19 samples from periodontitis varied significantly (0‐100% for CD23, 0‐36.2% for CD25) in spite of similar clinical status. The frequency of B‐cells and activated B‐cells in the gingivitis was much lower than that of periodontitis. These results indicate that both T‐cells and B‐cells were in active stage in periodontitis lesions. Differences of immunohistological features between gingivitis and periodontitis may be attributable to the heterogeneity of profiles of cytokine production by CD4+, CD45RO+“memory’ cells.
Differential expression of CR3, FcɛRll and FcγRlll on Polymorphonuclear leukocytes in gingival crevicular fluid
Authors: Sugita N. , Suzuki T. , Yoshie H. , Yoshida N. , Adachi M. , Hara K.
Published: July 2006

Polymorphonuclear leukocytes (PMNLs) are the most numerous cell population among the cellular infiltrates in gingival crevicular fluid (GCF) and play important roles in the host‐defensive system in the gingival crevices. We determined the percentage of neutrophils, cosinophils and basophils in total PMNLs by light microscopic observation using Randolph‐methylene blue staining, then assessed flow cytometric differences in the expression of CR3, FcγRIII, FcɛRII. LFA‐1α, and LFA‐Iβ on PMNL in GCF and peripheral blood (PB) from 21 patients with adult periodontius (AP) and 13 healthy donors. Percentages of basophils and eosinophils were higher in GCF than in PB. In both AP patients and healthy subjects, expression of CR3 and FcɛRll was higher while FeγRIII was lower in GCF than in PB. The statistical analysis showed that the expressions of FcγRIII and FcɛRII on GCF PMNLs were lower in AP patients than in healthy subjects. Expressions of LFA‐1α and β on GCF were similar to those on PB PMNLs. PB PMNLs stimulated in vitro with Porphyromonas gingivalts culture supernatant and fMLP displayed an expression pattern of CR3, FcγRIII and FcɛRII on GCF PMNLs. However, C5a and IL‐I failed to induce changes in FcγRIII and FcɛRII. The results indicate that GCF neutrophils are activated, present enhanced adhesion and a decreased IgG‐binding ability which would reflect that they are at the terminal stage of activation, and that GCF contains a larger eosinophil fraction than in PB. Moreover, these GCF eosinophils appear to be activated.
An in vitro study of the characteristics of a computer‐aided radiographic evaluation (CARE) system for longitudinal assessment of density changes
Authors: Zubery Yuval , Dove S. Brent , Ebersole Jeffrey
Published: July 2006

In recent years, several systems for computerized analysis of radiographs have been introduced, most of which use digital conversion of the image followed by subtraction of consecutive images to assess changes. This paper introduces a computer‐based qualitative and quantitative radiographic evaluation system based on the CADIA algorithm. Problems associated with computerized radiographic analysis are discussed and evaluation criteria for this type of system are suggested. These criteria include evaluation of system noise and threshold setting, reproducibility, and establishment of the system working curve (validity). The CARE system noise ranged from a ‐ 10 to + 10 CADIA value and the threshold was set on 13 for all measurements. The reproducibility was high, both for the radiographic technique and for repeated measurements. The working curve was established and showed the system's ability to detect small density changes of 0.048 O.D. which corresponds to 0.27 mm of aluminum thickness or compact bone equivalent. The linear range of the curve was between 0.7 and 1.8 O.D. By controlling the exposure parameters it was possible to work within the linear range of the curve. Based on these evaluation criteria, the CARE system can be used to quantitatively evaluate small density changes on sequential radiographs for early detection of caries and periodontal disease.
Molecular biology and life science
Authors: Matsubara Kenichi
Published: July 2006

Molecular biology has made the transition from phase 1, dealing with prokaryotic genes and DNA, to phase 2, dealing with genes of eukaryotic multicellular organisms. This transition came about because of the DNA technology that has evolved since the early 1970s. Now we are at the beginning of the transition to phase 3, through the emerging human genome project. The background of the development of this project, its current state, and its possible impact on the life sciences is briefly outlined and discussed.
Infection by Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans, and antibody responses at different ages in humans
Authors: Nakagawa S. , Machida Y. , Nakagawa T. , Fujii H. , Yamada S. , Takazoe I. , Okuda K.
Published: July 2006

This study examined the serum IgG and IgM responses against Porphyromonas gingivalis and 3 serotypes of Actinobacillus actinomycetemcomitans, and the correlations of these responses with age and homologous infection. A total of 90 individuals were included in this study: 40 subjects with gingivitis, 40 periodontally healthy subjects, and 10 adult periodontitis subjects. The subjects in the gingivitis and periodontally healthy groups were divided into 4 stages based on their physiological age: early childhood, school age, puberty, and adult. In the gingivitis group, there was a positive correlation between increase in age and increase in serum IgG antibody levels against P. gingivalis until puberty. However, no statistically significant difference was found between the puberty stage and the adult stage. The average level of IgG antibodies against A. actinomycetemcomitans in the school age gingivitis group was significantly higher than that in the early childhood gingivitis group for all serotypes (p < 0.01). In serotype c, IgG antibody levels in the school age gingivitis group were significantly higher than in the early childhood gingivitis group or the adult gingivitis group (p < 0.01). With both P. gingivalis and A. actinomycetemcomitans, positive correlations between elevated IgG level and infections by these microorganisms were found in the puberty gingivitis and adult periodontitis groups.
Histomorphometrical analysis of the effects of the bisphosphonate alendronate on bone loss caused by experimental periodontitis in monkeys
Authors: Weinreb M. , Quartuccio H. , Seedor J. G. , Aufdemorte T. B. , Brunsvold M. , Chaves E. , Kornman K. S. , Rodan G. A.
Published: July 2006

This study tested the efficacy of alendronate, a bisphosphonate, in reducing alveolar bone loss caused by experimental periodontitis in cynomolgus monkeys. Periodontitis was initiated in adult monkeys by ligating mandibular molar teeth at the cementoenamel junction (CEJ) and subsequently inoculating the ligature with Porphyromonas (Bacteroides) gingivalis. Controlateral, homologous non‐ligated teeth served as controls. Animals received, intravenously, either saline (placebo) or alendronate at 0.05 or 0.25 mg/kg every 2 weeks for 16 weeks. After the animals were sacrificed, coronal sections through mandibular molars were subjected to histomorphometrical analysis. No overt side‐effects were observed in any of the animals participating in this study. In placebo‐treated animals, ligation and inoculation resulted in significant bone loss both at the CEJ and at the furcation. Alendronate at 0.05 mg/kg significantly reduced bone loss associated with the experimental periodontitis at both sites. In contrast, the dose of 0.25 mg/kg was ineffective in attenuating alveolar bone loss in the furcation area and only slightly effective in preventing it at the CEJ area. The results of the histomorphometric analysis correlate closely with those of the radiographic analysis of the same experiment. These data indicate that alendronate could reduce the loss of alveolar support associated with periodontitis and suggest that bisphosphonates, by virtue of their significant inhibitory action on osteoclasts, may become a treatment modality in the battle against alveolar bone destruction during periodontal disease.
Local delivery of prostaglandin E1 induces periodontal regeneration in adult dogs
Authors: Marks S. C. , Miller S. C.
Published: July 2006

Formation of cementum, alveolar bone and periodontal ligament was produced in 18 sites on buccal surfaces of mandibular premolars and molars of 11 adult dogs near to sites of local delivery of prostaglandin E1 (PGE) for three weeks. Mineralizing bone and cementum were labelled with fluorescent dyes and polarizing microscopy showed periodontal ligament fibers between these new mineralized tissues. These observations extend recent demonstrations that local application of PGE causes formation of new bone on the mandible and suggest the potential for predictable, site‐directed periodontal regeneration.
Immunolocalization of fibronectin and vitronectin receptors in human gingival fibroblasts spreading on titanium surfaces
Authors: Hormia M. , Könönen M.
Published: July 2006

The adhesion and spreading of human gingival fibroblasls on glass and differently processed titanium surfaces was studied by immunolocalization of vinculin and the alpha and beta subunits of the fibronectin (α5β1) and vitronectin (αvβ3) receptors. Vinculin‐containing focal contacts were present both at 4 and 24 h of spreading in cells grown on glass or electropolished or etched titanium surfaces but not in cells spreading on sandblasted titanium surfaces. Immunostaining for the α5 and β1 subunits of the fibronectin receptor showed only a diffuse membrane fluorescence after 4 h of cell spreading irrespective of the growth surface. The αv and β3 subunits of the vitronectin receptor were at this stage detected in focal contacts in cells spreading on glass or electropolished or etched titanium surfaces. In cells spreading on sandblasted titanium surfaces, however, the vitronectin receptor had only a diffuse distribution. In cells that had been allowed to spread for 24 h on glass or electropolished or etched titanium surfaces the α5 and β1 integrin subunits were either diffusely distributed or showed a localization typical of extracellular matrix contacts. The αv and β3 integrin subunits were, as earlier, localized to typical focal contacts in cells grown on glass or electropolished or etched titanium surfaces. Cells attached to sandblasted titanium surfaces still expressed all the integrin subunits only diffusely. The results show that the surface texture of the substratum can affect the expression of integrin subunits in human gingival fibroblasts. As evidenced by the recruitment of integrin subunits to focal and extracellular matrix contacts, smooth or finely grooved titanium surfaces appear to be optimal in supporting the attachment of human gingival fibroblasts.
Role of periodontal ligament receptors in the tactile function of teeth: a review
Authors: Jacobs R. , van Steenberghe D.
Published: July 2006

The tactile function of the human periodontal mechanoreceptors has mostly been studied by psychophysical approaches. It was concluded that periodontal mechanoreceptors play a major role in the tactile function of teeth. It must be noted however that the interocclusal tactile threshold is not solely determined by periodontal mechanoreceptors but also by pulpal, muscular or articular receptors. While temporomandibular joint receptors play a minor role, muscular receptors are important in the discriminatory ability for a mouth opening of 5 mm and more. To discriminate between the contribution of periodontal and other receptors in the oral tactile function, future studies should use appropriate psychophysical methodologies and well‐defined stimulus parameters.
Effect of pre‐experimental maintenance care duration on the development of gingivitis in a partial mouth experimental gingivitis model
Authors: Van der Weijden G. A. , Timmerman M. F. , Danser M. M. , Nijboer A. , Saxton C. A. , Van der Velden U. , Van der Weijden Fridus
Published: July 2006

The present study was designed to evaluate if different periods of supervised oral hygiene prior to the experimental gingivitis trial have an effect on the amount of inflammation which develops in the ‘toothshield’ model. Two groups were compared. One group (Group A) was supervised over a 5‐month period before experimental gingivitis. Six months later Group A participated in a second trial, this time receiving only a 1‐month pretrial. A second group (Group B) which served as a control was supervised over a pre‐trial period of 1‐month prior to the start of the experimental gingivitis phase. During the pre‐trial period all subjects undertook a regime of vigorous oral hygiene which included polishing of the test quadrant in the upper jaw and supervised subgingival brushing, interdental taping or the use of toothpicks. The presence of plaque and bleeding were assessed. Following the pre‐trial period all plaque control measures in the experimental area were prevented during oral hygiene periods by the temporary placement of soft, loosely fitting vinyl toothshield guard. During this period they accumulated plaque rapidly and developed a generalized gingivitis. The results of this study indicate that, irrespective of the length of the pre‐trial period, subjects by group develop a comparable mean level of plaque and gingival bleeding. However, the extent to which gingivitis develops differs among individuals and was for a number of subjects not consistent. Therefore, in designing an experimental gingivitis trial care should be taken to include a sufficient number of subjects to account for individual variation.
Collagenase activity and tissue inhibitor of metalloproteinases‐1 (TIMP‐1) content in human whole saliva from clinically healthy and periodontally diseased subjects
Authors: Hayakawa H. , Yamashita K. , Ohwaki K. , Sawa M. , Noguchi T. , Iwata K. , Hayakawa T.
Published: July 2006

Total TIMP‐1 concentration in whole saliva of periodontally diseased subjects, 137 ± 67 ng/ml (mean ± SD), was clearly lower (p < 0.001) than that of clinically healthy subjects, 273±145, and that of edentulous subjects, 332±121. On the contrary, both active [1.58±0.35 units/ml (mean ± SD)] and total (2.08 ± 0.25) collagenase activities inTIMP‐1‐free whole saliva of diseased subjects were significantly higher than the activities (0.14 ± 0.14 and 0.50 ± 0.27, respectively) in TIMP‐1‐free whole saliva of healthy subjects. Most of the total collagenase in whole saliva of healthy subjects consisted of procollagenase, while mainly active collagenase was present in whole saliva from patients with periodontal diseases. Significant reciprocal changes of TIMP‐1 and collagenase levels, that is, increase in TIMP‐1 concentration and decrease in collagenase activity, were observed after the initial therapy of periodontitis patients.
Cytotoxicity in bacterial cultures: interaction and cell‐specificity, possible factors in periodontal disease
Authors: Johansson A. , Bergenholtz A. , Holm S. E.
Published: July 2006

Cytotoxicity in culture media of various growing bacterial strains was estimated by Cr‐51 release of labelled target‐cells. Interaction studies were made by adding each of the different UV‐killed bacteria to the medium with viable bacteria. The reference oral bacterial strains were: Actinobacillus actinomycetem‐comitans Y4, Porphyromonas gingivalis, Fusobacterium nucleatum and Streptococcus mitis, which were compared with the reference bacteria Staphylococcus aureus 209 and Staphylococcus epidermidis. The target cells were: gingival fibroblasts (GF), periodontal membrane fibroblasts (PMF), pulpal fibroblasts (PF), HeLa‐cells (HeLa), and lymphoid neoplasm cells (LN). Synergistic, as well as antagonistic, effects on target cells were observed. The cytotoxicity of A. actinomycetemcomitans in presence of P. gingivalis is neutralized while in presence of S. aureus it was increased. Bacterial interactions with F. nucleatum and P. gingivalis cytotoxicity were observed. The cytotoxicity of F. nucleatum was increased when cultured together with A, actinomycetemcomitans. Each cell type reacted differently to the toxicity of the supernatant of growth medium in which the same bacterial strain had been cultivated, which indicates cell specificity of the toxins.
Periodontal treatment needs in 12 and 15 to 19‐year‐old school children in the Caribbean island of Antigua, 1990
Authors: Vignarajah S.
Published: July 2006

A national survey was undertaken in 1990 to investigate the periodontal treatment needs in 12 and 15 to 19‐year‐olds residing in urban and rural areas of Antigua. Using the CPITN procedure, examination of 246 12 year‐old children and 456 adolescents (15–19 years) revealed that the CPITN scores of healthy, gingival bleeding, calculus, 4 or 5 mm and ≥6 mm periodontal pockets were distributed similarly in urban and rural areas. Calculus was the most commonly recorded score, with a prevalence of 46% in 12‐year‐olds and 56% in 15–19 year‐olds. 4 or 5 mm pockets were found in 14% of adolescents, affecting on average less than one sextant per subject, but deep pockets were uncommon, 26% of 12‐year‐olds and 14% of adolescents had periodontally healthy mouths. Scaling and oral hygiene instruction were the predominant treatment needs in both age groups, but the requirement for complex periodontal care in adolescents was low – 3% only.
Preliminary characterisation of antigens recognised by monoclonal antibodies raised to Porphyromonas gingivalis and by sera from patients with periodontitis
Authors: Cridland J. C. , Booth V. , Ashley F. P. , Curtis M. A. , Wilson R. F. , Shepherd P.
Published: July 2006

A panel of 15 monoclonal antibodies (MAbs) was raised to Porphyromonas gingivalis and used to characterise the antigens which they recognise by ELISA. immunofluorescence (IF), Western blotting and patient serum inhibition studies. All the MAbs were specific for P. gingivalis and did not recognise 24 other species. Eight MAbs gave bright ring‐like staining patterns against the majority of serotypes of P. gingivalis tested by IF. The antibodies could be grouped into 5 different antigen recognition profiles on Western blotting, and ELISA indicated that 8 of them bound to a capsular extract. Five antibodies bound to antigenic determinants recognised by sera from patients with periodontitis and 4 of these (1A1, 2B/H9, 3B1, 7D5) bound to a P. gingivalis 47kDa protease preparation on Western blotting. These antibodies are potentially useful for the purification and characterisation of biologically active components of P. gingivalis that are recognised by sera from patients with periodontitis.
Altered collagen metabolism in nifedipine‐induced gingival overgrowth
Authors: Tipton D. A. , Fry H. R. , Dabbous M. Kh.
Published: July 2006

Fibroblasts from nifedipine‐induced fibrotic gingiva (NFG) have been characterized with respect to several cellular functions which could contribute to the characteristic clinical overgrowth of the gingiva: collagen synthesis and breakdown, glycosaminoglycan production, fibronectin synthesis, and proliferation. Histologic examination of NFG tissue revealed a hyperplastic epithelium with elongated, branched rete pegs. The connective tissue consisted of densely‐packed collagen fibers and numerous enlarged fibroblasts, as well as regions of thinner, disorganized collagen fibers in the vicinity of scattered inflammatory and mast cells. Results of in vitro experiments showed that the fibroblast strains from the fibrotic gingiva (NFG) produced significantly greater amounts of collagen and lower levels of collagenase activity when compared to age‐ and sex‐matched normal human gingival fibroblast strains. The NFG fibroblasts did not produce significantly greater amounts of fibronectin, and their level of glycosaminoglycan production was less than that of the normal fibroblasts. The NFG fibroblasts did not proliferate significantly more rapidly than the normal fibroblast strains. These findings therefore show that there are defects in the regulation of collagen production by NFG fibroblasts in vitro, and suggest that these alterations in collagen metabolism contribute to the over‐deposition of collagen in this tissue, rahter than hyperproliferation of the fibroblasts or through the production of increased amounts of fibronectin and glycosaminoglycans.
Predominant microflora of severe, moderate and minimal periodontal lesions in young adults with rapidly progressive periodontitis
Authors: Kamma J.J. , Nakou M. , Manti F. A.
Published: July 2006

The purpose of this investigation was to study the microflora of severe, moderate and minimal periodontal lesions, in young adults with rapidly progressive periodontitis (RPP). Subgingival plaque samples were taken from 142 periodontal lesions in 10 young adults aging 25 to 35 years. The examination of the subgingival microflora indicated that certain species, including Porphyromonas gingivalis, Bacteroides forsythus, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, and Campylobacter species were found to be predominant in severe periodontal lesions. B. forsythus, P. gingivalis, Prevotella intermedia, F. nucleatum, Capnocytophaga ochracea, were predominant in medium lesions while Streptococcus species and Actinomyces species, C. ochracea, Haemophilus segnis and Veillonella parvula, were found in higher levels in minimal periodontal lesions.
Detection of periodontal probing change by analysis of distribution mean and skew
Authors: Cohen M.E.
Published: July 2006

A problem associated with probing measurement is that important site‐specific change may be obscured by measurement variability. Furthermore, if many sites are monitored there is an increasing likelihood that any particular “detected change” might be the result of this measurement error. Since error and multiplicity effects would tend to increase mouth‐wise false positive rate, demanding decision thresholds are often set. However, imposition of difficult criteria, increases site‐wise false negative rate and therefore reduces utility in the clinical setting. Evaluation of mean change might sometimes be a useful alternative, but also problematic as a few dramatic site‐level losses can be inconsequential among many stable or improving sites. A strategy is proposed for evaluating probing changes in a single patient, which is based on the statistical evaluation of two attributes of the change distribution. (1) Disease progression is concluded when mean probing loss increases over time, and (2) a clinically relevant asymmetry is concluded when the distribution tail corresponding to loss is skewed. Computerized simulation was used to determine α‐error for tests of mean and skew, for three different distributions of probing change. Actual α‐error was shown to be near nominal levels. Power was estimated as a function of the number and magnitude of sites with probing loss and as a function of whether there was change in both mean and skew or in skew alone. Under most conditions studied, simultaneous tests for skew and mean provided enhanced power relative to a test for loss alone and would appear to offer the clinician an additional statistical context for appraising disease status.
Effect of Campylobacter rectus LPS on plasminogen activator‐plasmin system in human gingival fibroblast cells
Authors: Ogura N. , Shibata Y. , Matsuda U. , Oikawa T. , Takiguchi H. , Izumi H. , Abiko Y.
Published: July 2006

The plasminogen activator (PA)‐plasmin system is implicated in the degradation of the extracellular matrix in inflammation through activation of metalloproteases and prekallikrein. We examined the activation of the PA‐plasmin system in human gingival fibroblast cells (Gin‐1 cells) following treatment with lipopolysaccharide (LPS) from Campylobacter rectus, which is frequently detected at sites of periodontal disease. The C. rectus LPS stimulated the plasmin activity in the conditioned medium of Gin‐1 cells in a time‐and dose‐dependent manner, and C. rectus LPS also stimulated the PA activity in the conditioned medium. The PA produced by Gin‐1 cells was determined to be urokinase PA (uPA), as prein‐cubation of Gin‐1 conditioned medium with anti‐uPA antiserum completely in‐hibited the PA activity while that with anti‐tPA antiserum had no inhibitory effect. The concentration of PA inhibitor‐1 (PAI‐1) in the conditioned medium was decreased by the addition of C. rectus LPS. Therefore, the enhancement of plasmin activity in the conditioned medium was dependent on increased uPA activity via the decrease of the PAI‐1 level of Gin‐1 cells treated with C. rectus LPS. Furthermore, the conditioned medium of Gin‐1 cells treated with C. rectus LPS showed significantly increased kallikrein activity, indicating the conversion of prekallikrein to kallikrein, which converts kininogen into kinin. These findings suggest that C. rectus LPS is a potent stimulator of inflammation of gingival tissue which acts through stimulation of the PA‐plasmin system.
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

Many 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

Using 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

Previous 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

To 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.
Response of human gingival fibroblasts to prostaglandins
Authors: Arai H. , Nomura Y. , Kinoshita M. , Shimizu H. , Ono K. , Goto H. , Takigawa M. , Nishimura F. , Washio N. , Kurihara H. , Murayama Y.
Published: July 2006

The effects of various prostaglandins (PGs) on the functions of human gingival fibroblasts (Gin‐1 cells; ATCC CRL 1292) were examined by phase‐contrast microscopy, cell‐counting and radioautographic experiments. Tested PGs were PGA1, PGA2, PGB1, PGB2, PGD2, PGE1, PGE2, PGF1α, PGF2α, PGI2, 6‐keto‐PGF1α, 9α‐11α‐methanoepoxy‐PGF2α, and thromboxane (TX) B2. PGA1, and PGD2 at 30 μM caused morphological deformation of Gin‐1 cells. All the PGs tested at 30 μM suppressed the proliferation of Gin‐1 cells in the logarithmic growth phase. Furthermore, all the PGs tested at 10 μM suppressed DNA synthesis, collagen synthesis, and noncollagenous protein synthesis in confluent Gin‐1 cells, while exerting no effect on GAG synthesis. The concentrations of PGs used are beyond those found in healthy gingiva. However, in periodontitis the local concentrations of some PGs within the gingiva are expected to be extremely elevated beyond the physiological level. These results suggest that PGs may play an important role as a negative regulator in metabolism and some pathologic gingival conditions by suppressing the functions of gingival fibroblasts.