bluuebunny/crossref_metadata_2025_split huggingface dataset:
Merits of Soft Nitriding Scalers
Authors: Fujimura Tetsuyuki , Nagai Atsushi , Kaneko Noriaki , Morishita Kouichiro , Ohta Norio , Kaya Hidehiro 
Published: February 2005

Background: It has been demonstrated that nitriding modifies the physical characteristics of metals. The purpose of this study was to evaluate the changes induced by 3 levels of inexpensive soft nitriding treatments on commercial sickle scalers. Methods: Taglite scalers (NT) were soft nitrided for 30 (SN30), 60 (SN60), or 90 (SN90) minutes. The cumulated scaled material was weighed every 10 strokes × 10 and thereafter every 1,000 to 8,000 strokes by an automatic scaling apparatus against epoxy resin. Weight differences were used to indicate abrasion resistance; the relative efficiency (RE) was calculated as the ratio of scaled amount at a given number of strokes (SN/NT). The hardness and the tensile strengths were determined for each soft nitriding treatment level. The nitrided layer thickness of representative SN scalers was observed by electron probe x‐ray microanalysis.Results: The SN60 was not significantly different from SN30 or SN90, but the SN90 was more efficient than SN30 for the first 100 strokes (P <0.01). The RE of all SN scalers was significantly greater (2.3 to 2.7 times) than the NT scalers from the beginning of the study and throughout all time periods (SN90> SN60 > SN30); it increased further during the first 100 strokes (9.7 to 15.5 times), indicating the NT scalers wore out faster than SN scalers. The untreated scalers' performance decreased to 10% of baseline after 100 strokes; but even after 1,000 strokes, the SN60 and SN90 performed better than new untreated scalers. Thereafter, all scalers' performance, including SN scalers, decreased. While the NT blades ceased to cut measurable amounts after 7,000 to 8,000 strokes, all SN scalers continued to cut. Although SN90 scalers had the thickest soft layer and were the hardest (P <0.01), the SN60 had the highest tensile strength (P <0.01), suggesting that it might be the safest in practice.Conclusions: Sixty minutes of soft nitriding treatment of commercially available taglite scalers seem to be the optimal treatment duration to increase their durability, on the order of 100 to 1,000 times, without jeopardizing safety for clinical use. J Periodontol 1999;70:1339‐1344.
Growth Factors Regulate Expression of Osteoblast‐Associated Genes
Authors: Strayhorn Christopher L. , Garrett J. Stephen , Dunn Richard L. , Benedict James J. , Somerman Martha J. 
Published: February 2005

Background: The goal of periodontal regenerative therapies is to reconstruct periodontal tissues such as bone, cementum, and periodontal ligament cells (PDL). The need to establish predictable treatment modalities is important for reconstruction of these tissues. The aim of this study was to determine the effects of a low molecular extract of bovine bone protein (BP) containing bone morphogenetic proteins (BMPs) 2, 3, 4, 6, 7, 12, and 13, alone or in combination with platelet‐derived growth factor (PDGF) and/or insulin‐like growth factor (IGF) on osteoblast differentiation in vitro.Methods: BP, mixed with a collagen matrix, was added to a poly (DL‐lactide‐co‐glycolide) polymer (PLG) and placed at orthotopic sites in the skullcaps of Sprague‐Dawleys rats. At day 28, rats were sacrificed for histological analysis. All sites treated with the polymer/BP produced bone while control sites (without BP) showed no bone formation. Having established the biological activity of BP, in vitro studies were initiated using MC3T3‐E1 cells, a mouse osteoprogenitor cell line. The ability of BP and other growth factors to alter cell proliferation was determined by Coulter counter, and differentiation was determined by Northern analysis for specific genes.Results: When compared with cells treated with 2% serum alone, PDGF enhanced cell numbers at 10 and 20 ng/ml; IGF produced no significant effect at these doses; and BP at 10 and 20 µg/ml decreased cell proliferation. Northern analysis revealed that PDGF blocked gene expression of osteopontin (OPN) and osteocalcin (OCN), while BP and IGF promoted gene expression of bone sialoprotein (BSP) and OPN. The combination of BP and IGF enhanced expression of OPN beyond that of either BP or IGF alone. PDGF was able to block the effects of IGF on gene expression, but not those of BP.Conclusions: These results indicate that BP, PDGF, and IGF influence cell activity differently, and thus raise the possibility that combining factors may enhance the biological activity of cells. J Periodontol 1999;70:1345‐1354
Immunohistologic and Morphometric Analysis of Cytotoxic T Lymphocytes in Gingivitis
Authors: Séguier Sylvie , Godeau Gaston , Leborgne Michelle , Pivert Gérard , Brousse Nicole 
Published: February 2005

Background: Gingivitis is an inflammatory phenomenon localized in gingival tissues and histologically characterized by an infiltration of several inflammatory cell populations. The purpose of this study was to characterize, localize, and quantify in situ inflammatory and cytotoxic T lymphocytes using immunolabeled gingival tissue sections in order to specify their implication during human gingivitis, since it is well known that such cells play an important role in the defense against bacterial elements.Methods: Paraffin gingival tissue sections from 7 patients with gingivitis (G) and from 7 clinically and histologically healthy controls (C) were immunohistochemically stained by specific antibodies (anti‐CD45, anti‐CD3, anti‐CD8, anti‐CD20, anti‐TIA‐1, anti‐GrB, and anti‐CD68), allowing the quantification of inflammatory cells in upper gingival epithelium (Ep), in the basal epithelium layer (BEp), and in upper connective tissue (CT). Collagen fibers were stained by sirius red F3Ba in order to evaluate, by morphometric and automated image analysis, the surface occupied by collagen bundles and to histologically confirm the absence of pathology of the clinically selected healthy controls.Results: In the gingivitis group, CD45+, CD3+, CD8+, TIA‐1+, and GrB+ lymphocyte numbers were significantly increased in Ep (P <0.05); and CD45+, CD3+, and TIA‐1+ lymphocyte numbers were significantly increased in BEp (P <0.05) compared respectively to Ep and BEp of group C. In Ep of group G, mean CD8+/CD3+ cell ratio was significantly increased (P <0.05) compared to BEp and CT, and 25% of TIA‐1+ cytotoxic cells were activated GrB+ cells.Conclusions: The present study suggests that intraepithelial cytotoxic T lymphocytes play an important role during gingivitis and CD8 expression and that activation of TIA‐1+ cytotoxic cells could be induced in Ep in response to epithelial environment. Thus, gingival epithelial tissue, which is generally only considered as a physical barrier, in fact contains numerous immune cell populations preventing the infiltration of pathogenic elements into the connective tissue. Particular clinical attention must be taken for the preservation of the epithelial tissue integrity. J Periodontol 1999;70:1383‐1391.
Periodontal Pathogens Stimulate CC‐Chemokine Production by Mononuclear and Bone‐Derived Cells
Authors: Jiang Yanling , Graves Dana T. 
Published: February 2005

Background: Chemokines are chemotactic cytokines that stimulate recruitment of leukocytes. Monocyte chemoattractant protein‐1, macrophage inflammatory protein‐1α, and RANTES (regulated on activation, normal T cell expressed, and secreted) are 3 well‐characterized CC‐chemokines that regulate mononuclear cell recruitment. The recruitment of inflammatory cells is of particular importance in the oral cavity because of the likelihood that cells will be challenged with bacteria either during acute infection or following surgical procedures. Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans are putative periodontal pathogens that may be harbored in subgingival and supragingival plaque. The capacity of the host to respond to these bacteria by the elaboration of chemoattractants may represent an important defense mechanism.Methods: In the present study, we examined CCchemokine production by human mononuclear cells and bone‐derived cells in response to P. gingivalis, A. actinomycetemcomitans and lipopolysaccharides (LPS) stimulation in vitro. The chemokines produced were measured by ELISA.Results: The results demonstrate that P. gingivalis and A. actinomycetemcomitans induce high levels of MIP‐1α in mononuclear cells. P. gingivalis and A. actinomycetemcomitans stimulated high levels of MCP‐1 in bone‐derived cells and induced moderate levels of RANTES production in both mononuclear and osteoblastic cells. In mononuclear cells, LPS induced high levels of MIP‐1α and RANTES and moderate levels of MCP‐1; in osteoblasts LPS only induced MCP‐1.Conclusions: The capacity of bacteria to induce a given chemokine depends upon the cell type stimulated. That different cell types would exhibit differences in the CC‐chemokines produced under the same stimulus provides a mechanism to explain tissue‐specific recruitment of leukocytes. J Periodontol 1999;70:1472‐1478.
The Accuracy of Radiographic Methods in Assessing the Outcome of Periodontal Regenerative Therapy
Authors: Toback Gregory A. , Brunsvold Michael A. , Nummikoski Pirkka V. , Masters Lisa B. , Mellonig James T. , Cochran David L. 
Published: February 2005

Background: The study of regenerative therapy in the periodontal intrabony defect has relied upon surgical re‐entry as the gold standard of outcome assessment. The search for a non‐invasive method has led to the application of various radiographic techniques in evaluating post‐treatment bone fill.Methods: The purpose of this study was to determine the ability of 2 forms of radiographic analyses (linear measurement and computer assisted densitometric image analysis, CADIA) to assess postsurgical bone fill as measured at a re‐entry procedure. A method that incorporates linear measurements and CADIA (linear‐CADIA) was developed and tested as well. Forty‐five intrabony defects in 15 patients were treated with open flap debridement, demineralized freeze‐dried bone allograft (DFDBA), or a combination of DFDBA and tetracycline. Standardized radiographs were obtained at baseline and at 1‐year postsurgery.Results: A 12‐month surgical re‐entry provided clinical measurements for post‐treatment bone fill. All radiographs were digitally scanned and analyzed on a computer. Fifty‐three percent of the defects were excluded from the study due to poor standardization or poor defect quality. Forty percent of all pairs of radiographs were judged to have poor standardization. In the first analysis, standardized images were subtracted and quantitatively analyzed utilizing CADIA. It was found that CADIA had the highest correlation with clinical bone fill when a region of interest (ROI) was examined in the middle portion of the defect. This quantitative evaluation provided very little clinically relevant information regarding actual bone fill. For the second analysis, pre‐ and post‐treatment linear radiographic measurements were obtained. In only 43% of the sites, did linear radiographic measurements determine post‐treatment bone fill within 1.0 mm of the clinical measurements. Overall, linear measurements underestimated bone fill by 0.96 mm (±1.2). These differences were statistically significant (paired Student t‐test, P = 0.0023). A method, which incorporates the use of both CADIA and linear radiographic measurements (linear‐CADIA), was tested. The linear‐CADIA method underestimated bone fill by 0.26 mm (±1.4), but these differences were not statistically significant (paired Student t‐test, P = 0.41).Conclusion: Linear radiographic measurements significantly underestimate post‐treatment bone fill when compared to re‐entry data. The linear‐CADIA method provided the highest level of accuracy of the 3 methods tested. This study also emphasizes the importance of developing a consistent method of radiographic standardization. J Periodontol 1999;70:1479‐1489.
Periodontal Disease in Patients With cleft Palate and Patients With Unilateral and Bilateral Clefts of Lip, Palate, and Alveolus
Authors: Gaggl Alexander , Schultes Günter , Kärcher Hans , Mossböck Rudolf 
Published: February 2005

Background: Long‐term health of the stomatognathic system, as well as esthetics, is the therapeutic goal in patients with facial clefts. The aim of this study was to analyze the periodontal situation of patients with cleft palate (CP) and cleft alveolus (CLPA) to elicit the differing degrees and localization of periodontal disease.Methods: In 30 patients with unilateral cleft lip, palate, and alveolus (UCLPA), 30 patients with cleft palate (CP), and 20 patients with bilateral cleft lip, palate, and alveolus (BCLPA), the gingival situation was identified and classified according to the sulcus bleeding index (SBI). Periodontal attachment loss and pathological loosening of teeth were noted for identification of periodontal lesions. The state of oral hygiene was recorded by the approximal plaque index (API).Results: In general, poor oral hygiene was found in all patients. The SBI showed a high incidence of gingivitis in patients with cleft lip, palate, and alveolus. Patients with cleft palate had a minor extent of sulcus bleeding, Periodontal disease was found to a similar extent to that in the general population in patients with cleft palate, whereas patients with cleft lip, palate, and alveolus had a predisposition to deep periodontal destruction of teeth adjacent to the cleft. The registration of pathological loosening of, a result of attachment loss, corresponded to the degree of periodontal disease shown by the attachment loss.Conclusions: A critical periodontal situation was found in patients with unilateral and bilateral cleft lip, palate, and alveolus. ultimately leading to tooth loss in the front tooth region. In contrast, patients with cleft palate exhibited periodontal situations similar to that found in the general population with additional damage, which may be attributed to orthodontic treatment. J Periodontal 1999;70:771‐178.
Polyamines Found in the Inflamed Periodontium Inhibit Priming and Apoptosis in Human Polymorphonuclear Leukocytes
Authors: Ratasirayakorn Waraporn , Leone Peter , Leblebicioglu Binnaz , Walters John D. 
Published: February 2005

Background: Polymorphonuclear leukocytes (PMNs) are exposed to high concentrations of polyamines in the inflamed periodontium and possess a transport system for taking up these compounds. Previous studies suggest that polyamines are involved in priming of the PMN respiratory burst by tumor necrosis factor‐α (TNF‐α) and can stabilize DNA against degradation. The purpose of this study was to determine whether exogenous polyamines can modulate priming by TNF‐α or delay nuclear changes associated with PMN apoptosis (programmed cell death). Methods: Isolated human PMNs were incubated with putrescine or spermidine in vitro. Superoxide generation was measured with a cytochrome C reduction assay, and apoptotic changes were assessed by fluorescence microscopy (after cell staining with acridine orange and ethidium bromide).Results: Incubation with 1 mM putrescine for 1 hour inhibited superoxide production by TNF‐primed PMNs by 20%, but enhanced the production of superoxide by unprimed cells by 38%. Both effects were dose dependent and statistically significant (P <0.03, repeated measures ANOVA and Dunnett's test). Spermidine had no significant effects on PMN oxidative function. With regard to apoptosis, 1 mM putrescine or spermidine produced a statistically significant reduction in the proportion of apoptotic PMNs within 6 to 9 hours (P <0.05). In cells incubated for 7 hours with 300 µM putrescine or spermidine, the proportion of apoptotic cells was approximately 30% lower than in untreated controls (P <0.05, Dunnett's test). The delay of apoptosis by spermidine was less profound than that produced by TNF‐α and was not additive to the effects of this cytokine.Conclusions: Polyamines could potentially impair the priming of PMN oxidative function by TNF‐α at sites where this cytokine is present. In the absence of TNF‐α, polyamines could enhance PMN superoxide release and enhance the maintenance of PMN function in the periodontal pocket. J Periodontol 1999;70:179‐184.
Effects of Cyclosporin A on Alveolar Bone: An Experimental Study in the Rat
Authors: Fu Earl , Hsieh Yao‐Dung , Nieh Shin , Wikesjö Ulf M.E. , Liu Demeral 
Published: February 2005

Background: There have been several investigations on the role of cyclosporin A (CSA) in gingival hyperplasia in both animals and humans. However, less attention has been given to the drug's effect on alveolar bone. This study used light microscopy to histologically and histometrically evaluate the effects of CSA on alveolar bone in the rat.Methods: Sixty, 6‐week‐old Sprague‐Dawley rats were separated into test and control groups. Animals in the test group received CSA in mineral oil (30 mg/kg body weight) daily by gastric feeding over the 6‐week study. Control animals received only mineral oil. Ten animals from each group were sacrificed at weeks 2, 4, and 6. After histologic processing, the labial crest of the alveolar bone in the anterior mandible was evaluated by light microscopy.Results: A distinct pattern of increased osteoclasia and reduced bone formation was observed in the CSA‐exposed animals compared to the controls. Increased osteoclasia was observed in periodontal sites and decreased bone formation was observed in symphyseal sites.Conclusions: The results suggest that CSA has distinct effects on alveolar bone. J Periodontol 1999;70:189‐194.
A Long‐Term Evaluation of Composite‐Bonded Natural/Resin Teeth as Replacement of Lower Incisors With Terminal Periodontitis
Authors: Quirynen Marc , Mongardini Claudio , Lambrechts Paul , De Geyseleer Caroline , Labella Roberto , Vanherle Guido , van Steenberghe Daniel 
Published: February 2005

Background: In patients with svere peridontitis, lower incisors are prone to terminal reakdown. This study assessed the longevity of composite‐bonded resin/natural teeth (reinforced only with a stainless steel mesh) as replacements for periodontally lost lower incisors. Methods: Besides the longevity of the restoration, the periodontal condition of the abutment teeth, and the general satisfaction of the patient were evaluated retrospectively via a phone interview, in combination with an analysis of the patient's clinical dental file. Results: The cumulative proportion of survival rate of these composite restorations was 80% after 5 years of function. No statistically significant difference was found between the survival distribution of one‐ and two‐pontic bridges (P = 0.66). The abutment teeth demonstrated stable probing depths and a negligible loss in attachment (0.1 mm/year). The satisfaction ratings were also favorable. Conclusions: The data seem to suggest that composite bonding of 1 or 2 teeth can be considered a semi‐permanent rehabilitation for the replacement of 1 or 2 periodontally lost lower incisors. J Periodontol 1999; 70: 205‐212.
Periodontal Bacteria in Adult Twins
Authors: Michalowicz Bryan S. , Wolff Larry F. , Klump David , Hinrichs James E. , Aeppli Dorothee M. , Bouchard Thomas J. , Pihlstrom Bruce L. 
Published: February 2005

Background: Both environmental and genetic factors are known to influence clinical measures periodontal disease. The purpose of this study was determine whether genetic factors similarly influence the presence of specific periodontal bacteria in subgingival plaque.Methods: Reared‐together and reared‐apart monozygous (MZ) and dizygous (DZ) adult twins were examined clinically. Demographic and behavioral information was obtained from each subject by questionnaire. Subgingival plaque samples were obtained from the index teeth, and the presence of P. intermedia, P. gingivalis, A. actinomycetemcomitans, E. corrodens, and F. nucleatum was determined using an immunoassay.Results: Microbiological and clinical data were available for 169 twin pairs. The subject‐based prevalences of the bacteria in the twin groups ranged from 11% for Porphyromonas gingivalis to 40% for F. nucleatum. For all species examined, the concordance rates were not significantly different (P > 0.05) between MZ and DZ twin groups. These findings were apparent despite similar smoking histories, self‐reported oral hygiene practices, and antibiotic use in the twin groups. Furthermore, MZ twins reared together were not more similar than MZ reared‐apart twins with respect to any bacterial species examined.Conclusions: These findings suggest that in a population with access to routine dental care, any effects that host genes and the early family environment have on the presence of specific bacteria in subgingival plaque are not apparent in adulthood. Most twins with disease in this study had early periodontitis. Results from this study may not necessarily be extrapolated to more advanced disease states. J Periodontol 1999;70:263‐273.
The Effect of Stress on the Inflammatory Response to Porphyromonas gingivalis in a Mouse Subcutaneous Chamber Model
Authors: Shapira Lior , Houri‐Haddad Yael , Frolov Igor , Halabi Amal , Ben‐Nathan David 
Published: February 2005

Background: The impact of emotional stress on the outcome of infectious diseases was studied in animal models and humans, but data related to the effect of stress on periodontal infection are limited. Using the subcutaneous chamber model in mice, the present study was carried out to investigate the effect of stress on the host response to Porphyromonas gingivalis.Methods: Mice with subcutaneous chambers (2 per animal) were divided into 4 treatment groups: cold‐stress; isolation‐stress; corticosterone (CS)‐injected; and controls. On the third day of stress conditions, heat‐killed P gingivalis were injected into the chambers. The chambers were sampled 1 and 5 days later and analyzed for leukocyte number, tumor necrosis factor (TNF)‐ α levels, and interferon (IFN)= γ levels.Results: injection of P gingivalis induced the migration leukocytes into the chambers and increased the intrachamber levels of IFN‐ γ and TNF‐ α . There were no significant differences in cell number and IFN‐ γ levels between the different treatment groups, but the levels of TNF‐ α were significantly lower in the isolation‐stress and cold‐stress groups compared to control animals. CS‐injected animals were not different from controls. In addition, the levels TNF‐ α in the stressed animals were lower on the fifth day post‐injection than on the first day, but not in the CS and control group.Conclusions: The results suggest that the levels of TNF‐ α induced by P. gingivalis in the infection site are downregulated in stressed animals, and CS is not the sole mediator responsible. The stress‐induced reduction in TNF‐ α levels might have an impact on the pathogenesis of periodontal disease in humans experiencing emotional stress. Periodontol 1999;70:289‐293.