bluuebunny/crossref_metadata_2025 huggingface dataset:
Cells With Osteoblastic Phenotypes Can Be Explanted From Human Gingiva and Periodontal Ligament
Authors: Carnes David L. , Maeder Christian L. , Graves Dana T.
Published: March 2012

Considerable phenotypic heterogeneity has been reported in gingival fibroblasts. Similarly, cells from the periodontal ligament (PDL) can be isolated with different phenotypes. Although it has been suggested that cells from the gingiva do not contribute to the formation of hard tissue, it is theoretically possible that under appropriate stimuli, immature mesenchymal cells‐ in gingiva could differentiate along an osteoblastic pathway. Differentiation of immature mesenchymal cells into osteoblasts following stimulation with osteoinductive factors has been demonstrated in muscle. We undertook experiments to establish whether cells with osteoblastic characteristics could be identified from human gingiva as well as from human periodontal ligament. Some cell populations from each of these tissues were found to have high basal alkaline phosphatase activity, to release osteocalcin in response to l,25(OH)2VitD3, and to form a mineralized matrix. Thus, cells can be isolated from the gingiva and PDL that exhibit phenotypic markers, which taken together are characteristic of osteoblastic cells. Other cell populations derived from the PDL and gingival connective tissue were isolated that had fibroblastic characteristics. These studies support the concept that gingival tissue can give rise to cells which may differentiate along either a fibroblastic or an osteoblastic pathway. J Periodontol 1997;68:701–707.
In Vitro Antifungal Properties of Mouthrinses Containing Antimicrobial Agents
Authors: Giuliana Giovanna , Pizzo Giuseppe , Milici Maria E. , Musotto Giuliana C. , Giangreco Rosalia
Published: March 2012

The purpose of this study was to investigate the in vitro antifungal properties of seven commercial mouthrinses containing antimicrobial agents. These included cetylpyridinium chloride (CPC), chlorhexidine digluconate (CHX), hexetidine (HEX), sanguinarine (SNG), and triclosan (TRN). The minimum fungicidal concentration (MFC) against six species of yeasts was determined by a broth macrodilution method. The kill‐time of mouthrinses at half the concentration of the commercial formulations was also determined. MFCs were achieved with each mouthrinse, except the SNG‐containing mouthrinse; against all the organisms being tested. However, the CPC‐containing mouthrinse appeared more active than the other products (P < 0.001). There were no significant differences in MFC values among CHX mouthrinse products, once adjusted for initial concentration differences (P = 0.1). Kill‐times of mouthrinses containing either CHX or CPC were less than or equal to 180 seconds with all the species of yeasts, and no significant differences were found among these products (P = 0.18). On the other hand, mouthrinses containing either TRN or HEX did not show a lethal effect on Candida albicans, Candida parapsilosis, or Candida guilliermondii. No kill‐times were achieved with the SNG‐containing mouthrinse. These results suggest that mouthrinses containing antimicrobial agents might represent an appropriate alternative to conventional antifungal drugs in the management of oral candidiasis. However, the effectiveness of antimicrobial mouthrinses as antifungal agents needs to be evaluated in further clinical trials. J Periodontol 1997;68:729–733.
The Effects of Different Tetracyclines on the Dentin Root Surface of Instrumented, Periodontally Involved Human Teeth: A Comparative Scanning Electron Microscope Study
Authors: Madison James G. , Hokett Steven D.
Published: March 2012

This in vitro study compares, by scanning electron microscope (SEM) examination, the surface effects of various topical applications of tetracycline on the instrumented dentin root surface of human teeth. Eighty‐two (82) dentin samples were prepared from periodontally‐compromised teeth planned for extraction. Solutions of tetracycline HCl, doxycycline, minocycline, sumycin, and a saline control were prepared and applied to the dentin samples for 0.5, 1, 3, 5, and 10 minutes. Each solution pH was measured: tetracycline HCl (pH 1.6), doxycycline (pH 2.2), minocycline (pH 3.8), sumycin (pH 4.4), and saline (pH 5.1). A tetracycline periodontal fiber was also evaluated at 1,4, 7, and 10 days of exposure for dentin surface effects. Tetracycline HCl removed the dentin smear layer leaving clean and open tubules significantly better than other solutions tested in as little as 30 seconds. Doxycycline and minocycline produced similar results to each other, which were significantly better than sumycin and saline, but not as effective as tetracycline HCl. Smear layer removal was attained by doxycycline and minocycline in five to ten minutes; however, sumycin and the saline control ineffectively removed the surface smear layer and dentinal tubules remained partially to totally occluded by debris. The periodontal fiber did not significantly alter the surface smear layer. Results of this study suggest that tetracycline HCl is the best current tetracycline form for root surface conditioning as measured by its ability to affect both dentin smear layer removal and dentin tubule exposure. J Periodontol 1997;68:739–745.
Spontaneous Bony Exposure: A Report of 4 Cases of Idiopathic Exposure and Sequestration of Alveolar Bone
Authors: Sonnier Keith E. , Horning Gregory M.
Published: March 2012

This paper describes 4 cases of spontaneous exposure and sequestration of alveolar bone. While one case was associated with an allergic mucositis, the other three were idiopathic involving large lingual exostoses. J Periodontol 1997;68:758–762.
Cytokine Production by Oral and Peripheral Blood Neutrophils in Adult Periodontitis
Authors: Galbraith Gillian M. P. , Hagan Charles , Steed R. Britt , Sanders John J. , Javed Tariq
Published: March 2012

Proinflammatory cytokines such as tumor necrosis factor‐α (TNF‐α) and interleukin 1β (IL‐1β) also possess bone‐resorptive properties, and are generally considered to play a role in the pathogenesis of periodontal disease. In the present study, TNF‐α and IL‐1β production by oral and peripheral blood polymorphonuclear leukocytes (PMN) was examined in 40 patients with adult periodontitis and 40 orally healthy matched controls. Oral PMN released considerable amounts of both cytokines in unstimulated culture, and. there was no difference between patients and controls when the cytokine levels were corrected for cell number. However, when the effect of disease activity was examined, cytokine release by oral PMN was found to be greatest in patients with advanced periodontitis. Within the healthy control group, IL‐1β production by oral PMN was significantly higher in males (Mann‐Whitney test, P = 0.0008). Examination of IL‐1β production by peripheral blood PMN exposed to recombinant human granulocyte‐macrophage colony stimulating factor revealed no difference between the patient and control groups. In contrast, IL‐1β production by peripheral blood PMN was significantly reduced in patients with advanced disease (Mann‐Whitney test, P = 0.02), and peripheral PMN IL‐1β synthesis was greater in female controls (Mann‐Whitney test, P = 0.054). No effect of race on cytokine production could be discerned in patients or controls. These results indicate that several factors influence cytokine production in oral health and disease, and that a dichotomy in cytokine gene expression exists between oral and peripheral blood PMN in adult periodontitis. J Periodontol 1997;68:832—838.
Reproducibility of Bone Height Measurements Made on Serial Radiographs
Authors: Hausmann Ernest , Allen Kristin
Published: March 2012

The objective of this study was to determine the reproducibility of alveolar bone height measurements made on digitized images of serial radiographs using 3 different alignment systems for taking serial radiographs: 1) XCP Rinn System, 2) XCP Rinn System modified to include an alignment pin, and 3) I /EGAD system (impression based‐electronically guided alignment device). Eighty duplicate films taken 1 hour apart of randomly selected anterior or posterior sites for alignment systems 1 and 2 were taken on 40 subjects. Thirty‐eight duplicate films were taken of posterior and anterior sites on 19 subjects with alignment system 3. Cemento‐enamel junction alveolar crest measurements were made on digital images using the side‐by‐side technique. Image pairs of serial radiographs were dichotomized into well‐matched and poorly matched groups based on subjective evaluation of the geometric likeness. Of those taken with system 1, 47% were well matched; with system 2, 62%; and with system 3, 98%. The measurement error of change in radiographic bone height, defined as twice the standard deviation of difference (mm), was determined. This varied between 1.03 mm for poorly matched radiographic pairs taken with alignment system 1 and 0.52 mm for all radiographic pairs taken with alignment system 3. These results can be used together with power calculations to select an alignment system for a particular study. For example, power calculations indicate that detecting a bone change of 0.5 mm using the I / EGAD system would require one‐third of the subjects needed when using the XCP Rinn method. J Periodontol 1997;68:839–841.
The Effect of Smoking on Serum IgG2 Reactive With Actinobacillus actinomycetemcomitans in Early‐Onset Periodontitis Patients
Authors: Tangada Srilatha D. , Califano Joseph V. , Nakashima Keisuke , Quinn Stephen M. , Zhang Ji‐Bo , Gunsolley John C. , Schenkein Harvey A. , Tew John G.
Published: March 2012

High titers of serum IgG2 reactive with Actinobacillus actinomycetemcomitans are present in early‐onset periodontitis (EOP) patients and it appears that anti‐A. actinomycetemcomitans may be protective. Smoking is associated with increased periodontal disease severity in generalized early‐onset periodontitis (G‐EOP) patients, but is not associated with periodontal disease severity in patients with localized juvenile periodontitis (LJP). Furthermore, smoking is associated with reduced serum IgG2 levels in black patients with G‐EOP but not in those with LJP. Based on this selective effect of smoking, we hypothesized that smoking would be associated with a reduction of specific IgG2 reactive with A. actinomycetemcomitans in black G‐EOP patients but not black LJP patients. In addition, we examined IgG2 responses to carbohydrate antigens from non‐periodontal pathogens including Haemophilus influenzae b Oligosaccharide antigen (Hib) and the Streptococcus pneumoniae antigen phosphocholine (PC). Smoking status was assessed from serum cotinine levels, and IgG2 specific for A. actinomycetemcomitans, Hib, and PC was assessed by ELISA. Our study revealed that smoking was correlated with a dramatic reduction in serum IgG2 anti‐A. actinomycetemcomitans in G‐EOP smokers but not in LJP smokers. In contrast, anti‐Hib IgG2 and anti‐PC IgG2 were not affected in either G‐EOP or LJP patients. In short, these results indicate that smoking is associated with a reduction in serum IgG2 antiA. actinomycetemcomitans in black G‐EOP subjects, but IgG2 reactive with other antigens may not be reduced in G‐EOP smokers. J Periodontol 1997;68:842–850.
Alveolar Bone Loss One Year Following Ovariectomy in Sheep
Authors: Johnson R.B. , Gilbert J.A. , Cooper R.C. , Dai X. , Newton B.I. , Tracy R.R. , West W.F. , DeMoss T.L. , Myers P.J. , Streckfus C.F.
Published: March 2012

There is little information concerning the incidence of alveolar bone loss in estrogen‐deficient women. Ovariectomized sheep are valid models for study of the effects of estrogen deficiency on bone metabolism. The objective of this study was to compare alveolar bone loss in control (C) and ovariectomized sheep (OVX) at 3 and 12 months following surgery. OVX animals had decreased serum levels of 17‐βestradiol and increased serum levels of osteocalcin, IL‐6, and urinary levels of deoxypyridinoline which, taken together, suggest development of osteoporosis. The mean probing depths and percentage of sites with pocket depths 4 to 6 mm and >6 mm were significantly greater in OVX than C at each time period and in OVX were significantly greater at 12 months than at 3 months. Gingival tissue interleukin‐6 (IL‐6) levels (but not the number of IL‐6(+) cells) were elevated adjacent to deep periodontal pockets; however, there was no significant elevation of levels of the proinflammatory cytokines IL‐1β and IL‐8 within gingiva. Taken together, the data suggest a systemic contribution for progression of periodontal disease associated with estrogen deficiency. This may involve upregulation of systemic IL‐6 synthesis and transfer to gingiva in serum, resulting in enhanced IL‐6 accumulation within the gingival tissues or reduced bone density allowing for a greater amount of alveolar bone loss. J Periodontol 1997;68:864–871.
Laser Irradiation of Bone. I. An In Vitro Study Concerning the Effects of the CO2 Laser on Oral Mucosa and Subjacent Bone
Authors: Krause Lana S. , Cobb Charles M. , Rapley John W. , Killoy William J. , Spencer Paulette
Published: March 2012

The purpose of this study was twofold: first, to evaluate the histologic effects of CO2 laser irradiation on biopsies of porcine oral mucosa and underlying bone under conditions that simulate the applications of the laser during gingival surgery; and second, to evaluate the histologic effects on cortical bone following irradiation with increasing energy densities. Specimens consisting of mucosa and underlying bone were subjected to multiple passes of the laser beam in the same line of incision at energy densities ranging from 240 to 1,032 J/cm2. A second group of specimens consisting only of cortical bone was irradiated by a single pass of the laser at energy densities ranging from 40 to 2,062 J/cm2. In both groups the mean depth of ablation, width of surface damage, and widths of the zones of thermal necrosis and thermal damage were determined. Results showed a direct correlation between increasing energy density and/or number of energy beam passes and increasing depths of ablation and widths of surface damage. Further, more than three passes at 1,032 J/cm2 penetrated the mucosal layer to involve underlying bone. The mean depth of ablation for bone specimens following a single pass of the energy beam ranged from 0.02 mm at 160 J/cm2 to a maximum of 0.75 mm at 2,062 J/cm2. Using those energy densities most common to oral soft tissue surgery, the mean depth of ablation in bone specimens ranged from 0.17 mm at 240 J/cm2 to 0.28 mm at 640 J/cm2 to 0.35 mm at 1,032 J/cm2. All specimens regardless of tissue composition, energy density, or number of energy beam passes exhibited a distinct layer of residual carbonized tissue, a zone of thermal necrosis characterized by tissue coagulation, and a zone of tissue exhibiting thermal damage. J Periodontol 1997;68:872–880.
Creeping Attachment Associated With the Connective Tissue With Partial‐Thickness Double Pedicle Graft
Authors: Harris Randall J.
Published: March 2012

The occurrence of creeping attachment has been documented with epithelialized autogenous masticatory mucosa grafts (free gingival grafts) and suggested in other root coverage techniques. The purpose of this study was to examine whether or not creeping attachment occurred after a connective tissue with partial‐thickness double pedicle graft had been performed. This study examined 22 defects, in 19 patients, treated where less than complete root coverage was obtained at 4 weeks postoperative. Creeping attachment occurred in 21 of the 22 defects (95.5%), in 18 of the 19 patients (94.7%). Complete root coverage occurred in 17 of the 22 defects (77.3%), in 15 of 19 patients (78.9%). The mean creeping attachment obtained was 0.8 mm. Additionally, it was the goal of this study to see if any factors could be associated with creeping attachment. This study did not find any factors that could be associated with the amount of creeping attachment seen. Creeping attachment seems to occur commonly, but complete root coverage is not predictable. J Periodontol 1997;68:890–899.
The Influence of Chlorhexidine on the Severity of Cyclosporin A‐Induced Gingival Overgrowth
Authors: Pilatti Gibson Luiz , Sampaio José Eduardo Cezar
Published: March 2012

The influence of chemical plaque control, using topically applied 0.12% chlorhexidine, on the severity of cyclosporin A (CsA)‐induced gingival overgrowth (GO) was evaluated. Forty Holtzman rats were divided into four groups: 1) control; 2) cyclosporin A: a 10mg/kg/day subcutaneous dose of CsA; 3) chlorhexidine: 0.12% chlorhexidine (CHX) was applied to the buccal surface of the right mandibular molars; and 4) cyclosporin A/chlorhexidine: a combination of the treatment described for cyclosporin A and chlorhexidine groups. The animals were fed a high sucrose diet during the experiment and were sacrificed after 14 and 21 days. The histometric analysis revealed a significant increase in buccal gingival area in the cyclosporin A group compared to other groups (P < 0.01) after 21 days. The epithelium thickness of the buccal gingiva was significantly increased in the cyclosporin A group, compared to the control group (P < 0.05). The cyclosporin A/chlorhexidine group exhibited statistically significantly lower gingival overgrowth than the cyclosporin A group. These findings, if replicated in human studies, suggest that topically applied 0.12% chlorhexidine may be a valuable measure in the management of cyclosporin‐induced gingival overgrowth. J Periodontol 1997;68:900–904.
A Comparison of the Site‐Specificity of Supragingival and Subgingival Calculus Deposition
Authors: Corbett Trudy L. , Dawes Colin
Published: March 2012

The aims of the present study on 40 patients were to quantitate by the Volpe‐Manhold method, the amount of supragingival (SPR) calculus, to determine qualitatively the amount of subgingival calculus (SBG), and to determine the association between supragingival and subgingival calculus on vestibular and lingual surfaces of all the teeth except third molars. Kappa values for intraexaminer reproducibility varied between 0.863 and 0.738. There was marked site‐specificity of SPR calculus scores, with the highest values by far on the lingual aspects of the lower anterior teeth: central incisor, lateral incisor, and canine, respectively. Although the grades for SBG calculus were higher on the lingual surfaces than on the vestibular surfaces of 25 of the 28 teeth, there was much less site‐specificity than for SPR calculus. For the teeth as a whole, there were significant associations (P < 0.001), as tested by chi‐square or Fisher's exact test, between SPR and SBG grades on both vestibular and lingual surfaces, between SPR grades on vestibular and lingual surfaces, and between SBG grades on vestibular and lingual surfaces. However, for individual teeth, or groups of similar teeth, only a few of the above associations were statistically significant. J Periodontol 1998;69:1–8.
Effects of Repeated Hand Instrumentation on the Marginal Portion of a Cast Gold Crown
Authors: Yagi Hiroaki , Ito Koichi , Eda Masahiro , Murai Seidai
Published: March 2012

A study was conducted to evaluate the effects of repeated hand instrumentation on the marginal portion of a cast gold crown. Seven extracted periodontally diseased premolare were used. The finishing line of the preparation was placed on the root surface and then the crown was cast and cemented in the usual manner. One proximal surface of each sample was divided into 2 areas: root planing (RP) area and RP plus polishing (RPP) area. The marginal portion of the crown was measured to give a baseline value using a surface roughness‐ and profile‐analyzing system. Then, the marginal portion was painted with a waterproof pen. RP was performed to remove paint in the RP are'a with the curets. In the RPP area, RP followed by polishing was done by silicone polishing points and a rubber cup with polishing paste. The relevant procedures and measurements were repeated 3 times in each area. Changes in the sample roughness and profile were evaluated and compared between the 2 techniques. The results showed that repeated instrumentation altered the surface of the marginal portion of the cast gold crown, resulting in increased roughness in both areas (P < 0.01). However, the roughness of the RPP area was considerably restored to the baseline value by polishing after RP. Therefore, it is suggested that polishing after RP smoothes the marginal portion of the cast gold crowns and appears to be an efficient prophylactic system. J Periodontol 1998;69:41–46.
Histologic Evaluation of Guided Tissue Regeneration Using 4 Barrier Membranes: A Comparative Furcation Study in Dogs
Authors: Lekovic Voja , Klokkevold Perry R. , Kenney E. Barrie , Dimitrijelic Bozidar , Nedic Milica , Weinlaender Michael
Published: March 2012

This study evaluated and compared four different barrier membrane materials used to treat class II mandibular premolar and molar furcations in seven dogs with naturally occurring periodontitis. Five class II furcation defects in each animal were randomly assigned to one of four experimental groups or to a control group. Each defect was treated by surgical debridement, root planing, and barrier membrane coverage with one of the four test materials or no barrier membrane (control). Thus, each animal served as its own control. Following 6 months of healing, block sections were used to histologically measure the amount of regenerated tissue and stereometrically enumerate the inflammatory cell infiltration observed with each of the treatment modalities. The four barrier membrane materials (polycarbonate filter, silicone rubber, expanded polytetrafluoroethylene, and polycaprolactone) all provided a wound healing environment that promoted new cementum formation, with mean values ranging from 1.96 ± 0.031 mm to 2.18 ± 0.015 mm, and facilitated alveolar bone regeneration, with mean values ranging from 1.18 ± 0.019 mm to 1.44 ± 0.014 mm. Controltreated sites showed mean values of only 0.24 ± 0.007 mm new cementum formation and 0.32 ± 0.017 mm bone fill. Polycarbonate filter and polycaprolactone membrane barriers elicited a significantly greater chronic inflammatory cell response of lymphocyte and plasma cell infiltrates as compared to expanded polytetrafluoroethylene and silicone rubber, which were comparable to control‐treated sites. J Periodontol 1998;69:54–61.
An Immunocytochemical Study for Lysosomal Cathepsins B and D Related to the Intracellular Degradation of Titanium at the Bone‐Titanium Interface
Authors: Ayukawa Yasunori , Takeshita Fumitaka , Yoshinari Masao , Inoue Takashi , Ohtsuka Yoshiro , Shimono Masaki , Suetsugu Tsuneo , Tanaka Teruo
Published: March 2012

The morphological relationship between titanium and lysosomal proteinases, cathepsins B and D, at the bone‐titanium interface using titanium‐coated plastic implants placed for 28 days in the tibiae of 6‐week‐old rats was immunocytochemically investigated by the colloidal immunogold‐silver method. Under light microscopy the titanium layer appeared to make direct contact with the bone and one or a few layers of slender cells were interposed between the bone and titanium. Ultrastructurally, the titanium came in contact with the bone or the slender cell layer through a 20 to 40 nm thin amorphous zone. The slender cells at the bone‐titanium interface consisted of two types; one was an Osteoblast type with glycogen granules which was found along the newly‐formed bone facing titanium layer. The other was a fibroblast type which came in contact with the titanium layer and occasionally endocytosed the detached titanium fragments. In addition, some of the slender cells also showed degenerative changes. Immunocytochemically, cathepsins B and/or D were sometimes colocalized in some phagolysosomes with titanium fragments. These findings suggested that the fibroblast types at the bone‐titanium interface may act as scavengers to remove both cell debris and titanium by means of some endocytotic ability, and lysosomal cathepsins also developed in response to the endocytosed titanium. The Osteoblast type also appears to show a high degree of osteogenic activity around the titanium‐coated plastic implants. J Periodontol 1998;69:62–68.
Subgingival Distribution of Periodontopathic Bacteria in Adult Periodontitis and Their Susceptibility to Minocycline‐HCl
Authors: Hagiwara S. , Takamatsu N. , Tominaga Y. , Umeda M.
Published: March 2012

The purpose of this study was to investigate the distribution of several periodontopathic bacteria in adult periodontitis, their in vitro susceptibility to minocycline‐HCl, and whether the efficacy of the drug changes with a decrease in bacterial susceptibility. Twenty‐one patients (43 to 75 years old) with 62 periodontal lesions from pockets ≥4 mm participated in the study. After subgingival sampling, an ointment containing 2% minocycline‐HCl was applied locally to the selected pockets once a week for 4 weeks. The lesions were clinically examined after 1 and 4 weeks of administration. The distribution of the subgingival microorganisms included Capnocytophaga sputigena (37.1%), Prevotella intermedia (22.6%), Porphyromonas gingivalis (22.6%), Fusobacterium nucleatum (20.1%), Actinobacillus actinomycetemcomitans (9.7%), and Eikenella corrodens (4.8%). The distribution was complex, with 76.8% of the sites containing 1 to 3 bacterial spieces. The minimum inhibitory concentration (MIC) of minocycline‐HCl for each organism showed that most were inhibited by a minocycline‐HCl concentration equal to or less than the MIC for reference strains. However, some clinical strains of Prevotella intermedia seemed to exihibit low susceptibility to minocycline‐HCl. There were no significant differences among sites with strains exhibiting low or normal susceptibility to minocycline‐HCl. The concentration of the drug applied to deep periodontal pockets inhibited the growth of most of the microorganisms investigated in this study. J Periodontol 1998;69:92–99.
Early‐Onset and Adult Periodontitis Associated With Abnormal Cytokine Production by Activated T Lymphocytes
Authors: Sigusch B. , Klinger G. , Glockmann E. , Simon H.‐U.
Published: March 2012

There is growing evidence for an important role of the immune system in the pathogenesis of periodontitis. To further characterize the possible immunoregulatory dysfunction of peripheral blood mononuclear cells (PBMC) in periodontitis patients, we investigated functional aspects of PBMC from patients with early‐onset periodontitis (EOP) and adult periodontitis (AP). Compared to controls, we observed decreased proliferative responses of PBMC from patients with EOP following stimulation with a mitogenic stimulus (phytohemagglutinin). To investigate whether this abnormality reflects a modulation in cytokine production, we measured the in vitro production of interleukin (IL)‐3, IL‐5, granulocyte macrophage colony‐stimulating factor (GM‐CSF), and interferon‐γ (IFN‐γ) by activated PBMC. PBMC in EOP patients expressed significantly decreased levels of IFN‐γ protein in response to mitogenic stimulation. Reduced IFN‐γ secretion was associated with decreased IFN‐γ and IL‐2 mRNA expression in these cells, as well as decreased HLA‐DR surface expression on monocytes. On the other hand, we observed significantly higher levels of IL‐5 and GM‐CSF in the same system using PBMC from AP patients. These were comparable to the levels observed for patients with allergic asthma. These data imply that EOP is associated with decreased Th1‐like cytokine expression, and that the PBMC response from patients with AP is predominantly Th2/Th0 in nature. J Periodontol 1998;69:1098–1104.
Gingival Epithelial Cells Increase Interleukin‐8 Secretion in Response to Actinobacillus actinomycetemcomitans Challenge
Authors: Huang George T.‐J. , Haake Susan Kinder , Park No‐Hee
Published: March 2012

Periodontal diseases result from the interaction of bacterial pathogens with the host gingival tissues. The role of gingival epithelial cells in the initiation of host defense mechanisms after encountering oral bacteria has not been investigated. Actinobacillus actinomycetemcomitans is a key periodontal pathogen that adheres to and invades oral epithelial cells. Thus, we examined whether gingival epithelial cells increase secretion of the potent neutrophil chemoattractant interleukin‐8 (IL‐8) following A. actinomycetemcomitans challenge. Normal human oral keratinocytes (NHOK), isolated from gingival tissue, and 3 oral epithelial cell lines (HOK‐18A, HOK‐16B‐BaPT1, and HEp‐2) were co‐cultured with A. actinomycetemcomitans for 2 hours to allow bacteria–epithelial cell interactions. The epithelial cells were then washed, and fresh medium with gentamicin was added to kill extracellular bacteria. Cell cultures were further incubated for 24 hours before the supernatant was collected for IL‐8 detection with ELISA. The results showed that IL‐8 secretion increased 2‐ to 7‐fold 24 hours after bacterial challenge. The highest IL‐8 secretion was at the multiplicity of infection (MOI) of 1,000:1 in bacterial dose response studies using HOK‐16B‐BaP‐T1 cells. Time‐course studies revealed that IL‐8 secretion rapidly reached a maximum level 6 hours after bacterial challenge and subsequently decreased to basal levels. These data indicate that gingival epithelial cells are capable of upregulating IL‐8 expression rapidly in response to A. actinomycetemcomitans challenge and thus may facilitate the recruitment of neutrophils as a host defense mechanism. J Periodontol 1998;69:1105–1110.
Risk Indicators for Harboring Periodontal Pathogens
Authors: Umeda M. , Chen C. , Bakker I. , Contreras A. , Morrison J.L. , Slots J.
Published: March 2012

The risk for harboring 6 putative periodontal pathogens in 4 selected periodontal pockets, in whole saliva, or in either site (i.e., orally) was determined in 52 Caucasians, 49 African‐Americans, 48 Asian‐Americans, and 50 Hispanics living in Los Angeles. 16S rRNA PCR analysis assessed the presence of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, and Treponema denticola. Step‐wise regression analysis determined the relationship between the occurrence of each organism and various explanatory variables (risk indicators). Periodontal probing depth or disease severity was positively associated with all 6 study organisms. African‐Americans carried an increased risk for harboring P. gingivalis in saliva (odds ratio [OR] 2.95) and orally (OR 2.66), and a reduced risk for harboring T. denticola orally (OR 0.34). Asian‐Americans showed an increased risk for harboring A. actinomycetemcomitans in periodontal pockets (OR 6.63) and P. gingivalis in periodontal pockets (OR 5.39), in saliva (OR 5.74), and orally (OR 5.81). Hispanics demonstrated an increased risk for harboring A. actinomycetemcomitans in periodontal pockets (OR 12.27) and P. gingivalis in periodontal pockets (OR 6.07), in saliva (OR 8.72), and orally (OR 7.98). Age was positively associated with the prevalence of P. gingivalis in saliva (OR 1.20) and orally (OR 1.20), and of A. actinomycetemcomitans orally (OR 1.18). The male gender was a risk factor for harboring P. intermedia in periodontal pockets (OR 2.40), in saliva (OR 3.31), and orally (OR 4.25), and for harboring P. nigrescens in saliva (OR 2.85). The longer the subjects resided in the United States, the less likely A. actinomycetemcomitans was detected orally (OR 0.82). Former smokers demonstrated a decreased risk for harboring A. actinomycetemcomitans in saliva (OR 0.23). Current smokers displayed an increased risk for harboring T. denticola in periodontal pockets (OR 4.61). The number of dental visits in the past 10 years was inversely related to the prevalence of P. intermedia orally (OR 0.96). The prevalence of P. intermedia in saliva was positively associated with the length of time from the last dental visit (OR 1.01). This study suggests that genetic and/or environmental factors predispose subjects to oral colonization by putative periodontal pathogens. J Periodontol 1998;69:1111–1118.
Cytokine Profiles of Lesional and Splenic T Cells in Porphyromonas gingivalis Infection in a Murine Model
Authors: Gemmell Erica , Winning Tracey A. , Bird Philip S. , Seymour Gregory J.
Published: March 2012

T cell cytokine profiles in the spleens and Porphyromonas gingivalis‐induced lesions of P. gingivalis‐immunized mice were examined. BALB/c mice were immunized with P. gingivalis outer membrane (OM) antigens/mouse weekly for 3 weeks followed by challenge with live organisms 2 weeks after the final immunization. Control mice were immunized with PBS. Spleens were excised at 0 and 4 days and lesions at 1, 4, and 7 days after challenge. Splenic and lesionai CD4 and CD8 cells were stained for intracytoplasmic interleukin (IL)‐4, interferon (IFN)‐gamma, and IL‐10. More than 50% of the T cells in the spleens of immunized mice were IFN‐gamma positive at day 0 which was significantly higher than for IL‐4 or IL‐10, these levels decreasing significantly 4 days after challenge. Less than 6% of the T cells in sham immunized mice were cytokine positive at day 0, although at day 4, there was a significant increase in the percent IL‐10 positive CD4 cells and IL‐4 and IL‐10 positive CD8 cells. There were no differences in the percent IL‐4, IFN‐gamma, or IL‐10 positive T cells in the lesions of immunized mice, but there was a dramatic decrease at day 7 to very low levels in control mice. In conclusion, the results of the present study show a predominant Th1 response in the spleens of BALB/c mice after immunization with P. gingivalis OM antigens, suggesting that a protective immune response to P. gingivalis may involve a strong IFN‐gamma response. J Periodontol 1998;69:1131–1138.
Microbiological Findings in Prepubertal Periodontitis. A Case Report
Authors: Dibart Serge , Chapple Iain L.C. , Skobe Ziedonis , Shusterman Stephen , Nedleman Howard L.
Published: March 2012

Generalized pre‐pubertal periodontitis (GPP) is a rare entity that usually affects children with severe systemic diseases. We report the case of a 7‐year‐old male patient diagnosed with GPP, with no apparent systemic condition, who lost all his primary teeth to periodontal disease. Before extractions, while he was still in mixed dentition the subgingival plaque was collected and analyzed using DNA probes to 40 different microorganisms. Putative periodontopafhogens such as Prevotella intermedia, Selenomonas noxia, Fusobacterium nucleatum, and Actinobacillus actinomycetemcomitans could be identified throughout the mouth. More intriguing was the colonization of the sulcus of some secondary teeth by potentially harmful microorganisms found in pockets of diseased adjacent primary teeth. J Periodontol 1998;69:1172–1175.
Effects of Bioabsorbable and Non‐Resorbable Barrier Membranes on Bone Augmentation in Rabbit Calvaria
Authors: Ito Koichi , Nanba Koichi , Murai Seidai
Published: March 2012

The aim of this study was to compare the effects of bioabsorbable and non‐resorbable membranes on experimental guided bone augmentation in 8 Japanese white rabbits. A cutaneous flap was demarcated and raised from the forehead of each animal, the periosteum was lifted, and the calvarial bone on both sides of the midline was exposed. A titanium screw was inserted into the bone on each side of the midline and one screw was covered with a bioabsorbable (polylactic acid) membrane and the other with a non‐resorbable (expanded polytetrafluoroethylene) membrane. The implanted screws and membranes were then covered with the periosteum and cutaneous flap. After healing for 6 months, the animals were euthanized and the experimental area was prepared for histological investigation. New bone had formed under both membranes with no sign of infection or membrane exposure. The amount of newly generated bone (89.0 ± 17.3% versus 54.7 ± 14.0%, P <0.05) and the percentage of newly generated bone height (81.5 ± 6.3% versus 58.9 ± 7.8%, P <0.05) in the space beneath the non‐resorbable membrane was greater than that beneath the bioabsorbable membrane. However, there were no statistically significant differences between the bioabsorbable and non‐resorbable membranes with respect to the percentage areas of mineralized bone (52.3 ± 11.3% versus 47.1 ± 6.7%, P = 0.8658) and bone marrow (47.7 ± 11.3% versus 52.9 ± 6.7%, P = 0.4838) and bone contact with the screw (88.3 ± 6.9% versus 89.2 ± 7.3%, P = 0.9999). In conclusion, at least within the limitations of this rabbit model, we suggest that non‐resorbable membranes with sufficient stiffness should be used to obtain greater bone volume and height instead of bioabsorbable membranes for the GBR procedure, and that this will facilitate predictable bone augmentation in spaces beyond the bone surface. Therefore, the bioabsorbable membrane could not replace the non‐resorbable membrane used in this model. J Periodontol 1998;69:1229–1237.
Protein Extracts of Dentin Affect Proliferation and Differentiation of Osteoprogenitor Cells In Vitro
Authors: Takata T. , D'Errico J.A. , Atkins K.B. , Berry J.E. , Strayhorn C. , Taichman R.S. , Somerman M.J.
Published: March 2012

Proteins associated with the mineral phase of dentin are considered to have the potential to alter cell function within the local environment, during development and regeneration of tooth/periodontal tissues. Cells that may be altered include osteoblasts, ameloblasts, periodontal ligament cells, odontoblasts, and cementoblasts. However, specific factors within dentin controlling cell activity have not been elucidated. To investigate further the role of dentin proteins in regulating cell behavior, MC3T3‐E1 cells, a mouse osteoprogenitor cell line, were exposed to guanidine/EDTA extracts of dentin (G/E‐D) prepared from bovine teeth. Cells, with or without G/E‐D (2 to 50 μg/ml), were evaluated for proliferative activity and for mRNA expression of bone‐associated genes. Results indicated that G/E‐D suppressed cell proliferation and caused striking morphological changes, including the conversion of cuboidal cells into fibroblastic, spindle‐shaped cells. Markers of Osteoblast differentiation, osteocalcin and bone sialoprotein mRNA were decreased, while osteopontin mRNA was enhanced in cells exposed to G/E‐D. Since transforming growth factor beta (TGFβ1) has been reported to influence cells in a similar fashion, G/E‐D were examined for the presence of and concentration of TGFβ using slot blot analysis and enzyme immunoassay (ELISA), respectively. These analyses demonstrated that G/E‐D contained 6.6 ng/mg of TGFβ1. Next, cells were exposed to G/E‐D in conjunction with anti‐TGFβ1,2,3 antibody. When cells were exposed to antibody, G/E‐D‐mediated changes in morphology and gene expression were blocked. These results suggest that TGFβ1 and perhaps other factors in dentin can regulate cell behavior and, therefore, can influence development, remodeling, and regeneration of mineralized tissues. J Periodontol 1998;69:1247–1255.
Isolation of Human Osteoblast‐Like Cells and In Vitro Amplification for Tissue Engineering
Authors: Malekzadeh Reza , Hollinger Jeffrey O. , Buck Dave , Adams Donald F. , McAllister Bradley S.
Published: March 2012

As the field of dental implants continues to grow at a rapid rate so does our quest to find new techniques to enhance bone grafting. Tissue engineering is an exciting new technique in bone grafting. Therefore, the purposes of this study were to develop a simple, reproducible method to isolate human osteoblast‐like cells (HOBs) and to evaluate in vitro cell proliferation within 2 different 3‐dimensional (3‐D) constructs targeted for tissue engineering applications. Ultimately, HOBs that have been amplified within 3‐D constructs may be employed for bone regeneration techniques, such as onlay and sinus grafting prior to implant placement. Our cell isolation protocol employed human fetal calvaria tissue sequentially digested with trypsin and collagenase. The HOB cells from only the third and fourth digests were obtained, cultured and evaluated within the constructs. An osteoblast‐like phenotype was in part verified for these HOB cells by demonstrating a significantly higher alkaline Phosphatase activity than for human gingival fibroblasts, and a comparable level to the Osteoblast cell line MG‐63. The HOB cells were cultured within either poly (D,L‐lactide) (PLA) or a fused fiber ceramic and evaluated for the ability to support in vitro HOB amplification. HOB proliferation was validated by scanning electron microscopy, identifying cells throughout the 3‐D constructs. Continuous cell viability was demonstrated for the duration of the 33‐day evaluation period and the extent of cell amplification reached approximately 20 times the seeding density. The in vitro amplification results further indicate that tissue engineering strategies with either the PLA or fused fiber construct may be suitable for bone regeneration therapy for dental implants. J Periodontol 1998;69:1256–1262.
Change in Temperature of Subjacent Bone During Soft Tissue Laser Ablation
Authors: Spencer Paulette , Cobb Charles M. , Wieliczka David M. , Glaros Alan G. , Morris Patrick J.
Published: March 2012

In tissues that closely approximate bone, sufficient heat may be transferred to the bone during laser surgery to cause damage and/or necrosis. To date, there have been few studies examining the temperatures elicited at the bone surface as a result of laser application to the overlying soft tissues. The purpose of this investigation was to determine, under in vitro conditions, temperature changes at the bone/soft tissue interface during laser ablation with CO2 and Nd:YAG lasers used with and without (w/wo) air/water coolant. Experimental specimens consisted of 5 mandibles from freshly sacrificed hogs; laser treatment sites were the buccal and lingual attached gingiva of the molars and the lingual keratinized mucosa of the incisor region. CO2 and Nd:YAG lasers were used w/wo coolant at power settings of 4 to 8 W and 5 to 9 W, respectively. Temperature changes were measured with a copper constant thermocouple contained within a 21 gauge hypodermic needle. In comparing the lasers at comparable energy densities w/wo coolant, temperature increases at the bone/soft tissue interface ranged from 8.0 to 11.1°C with the Nd:YAG and 1.4 to 2.1°C with the CO2. Similarly, in comparing the times required for the interface to return to baseline temperature following removal of the laser, values ranged from ~143 to 205 and ~119 to 139 seconds for the NdYAG and CO2, respectively. Results from this study suggest that, at energy densities equal or above those reported here, the increase in temperature at the bone surface as a result of periodontal soft tissue surgery with the NdYAG laser could be damaging, especially if the exposure is prolonged. J Periodontol 1998;69:1278–1282.
Root Coverage With a Connective Tissue With Partial Thickness Double Pedicle Graft and an Acellular Dermal Matrix Graft: A Clinical and Histological Evaluation of a Case Report
Authors: Harris Randall J.
Published: March 2012

Root coverage can be achieved by many techniques. In this case report a patient was treated with a connective tissue with partial thickness double pedicle graft, which resulted in complete root coverage. However, 6 days postsurgery the patient developed a bleeding problem from the palatal donor area. For this reason, a unique approach was used to treat the next area needing root coverage. The procedure combined an acellular dermal matrix and a coronally positioned pedicle. The procedure was used to treat 3 defects. Complete root coverage was obtained on 2 of the 3 defects. The third was covered to within 1 mm of the cemento‐enamel junction (CEJ). Histology showed similar results with a connective tissue graft and an acellular dermal matrix. Verhoeff's staining demonstrated that the acellular dermal matrix was incorporated into the gingival tissue. This case report demonstrated that acceptable results can be obtained with the connective tissue with partial thickness double pedicle graft and the acellular dermal matrix combined with a coronally positioned pedicle, both clinically and histologically. J Periodontol 1998;69:1305–1311.
An Assessment of the Osteoinductive Potential of Commercial Demineralized Freeze‐Dried Bone in the Murine Thigh Muscle Implantation Model
Authors: Garraway R. , Young W.G. , Daley T. , Harbrow D. , Bartold P.M.
Published: March 2012

Early studies have demonstrated that implantation of laboratory preparations of demineralized freeze dried bone (DFDB) into the thigh muscle of mice induces ectopie osteoinduction. However, with the development of commercial preparations of DFDB for clinical use, concerns have been raised as to the osteoinductive properties of such preparations. The aim of this study was to investigate the osteoinductive potential of some commercial preparations of DFDB compared to a newly developed product which incorporates DFDB into a collagen sponge. Commercial preparations of DFDB or the DFDB/collagen sponge were inserted into the thigh muscles of 60 adult Swiss CD‐1 mice. At the completion of each experimental period (7, 14, 30, 90 and 180 days), the animals were sacrificed, and the hindquarters of the mice were radiographed. The area where each graft had been placed was then excised, processed for light microscopy, and stained with hematoxylin and eosin or von Kossa's stain. Histological analysis of the DFDB/collagen sponges demonstrated significant remineralization which increased with time. Remineralization of the DFDB/collagen sponges was verified by radiographs which showed a significant increase in radiopacity over time. There was no radiographic evidence of mineralized tissue formation or remineralization in any of the commercial DFDB samples studied. At all time points studied, histological analyses failed to show evidence of bone formation for any of the preparations. The results suggest that commercially available DFDB is not osteoinductive in the murine model and question the use of such materials in clinical periodontics. The results found for the DFDB/collagen sponge indicate a different mechanism of activity from DFDB as evidenced by its rapid remineralization. The role this remineralization process has in osteoinduction is unknown and requires further study. J Periodontol 1998;69:1325–1336.