bluuebunny/crossref_metadata_2025_split huggingface dataset:
Should Cementoblasts Express Alkaline Phosphatase Activity? Preliminary Study of Rat Cementoblasts In Vitro
Authors: Gao Jin , Symons Anne L. , Haase Helen , Bartold P. Mark 
Published: February 2005

Background: A well‐characterized cell culture model for cementoblasts is essential to understand the mechanisms of periodontal ligament (PDL) reattachment and regeneration. Whether cementoblasts express alkaline phosphatase (ALP) activity in vivo and in vitro remains to be determined.Methods: Using a 2‐step method of enzyme digestion/explant culture, osteoblasts, gingival/PDL fibroblasts, and cementoblasts were obtained from alveolar bone, gingiva, and the root surface of rat first molars and cultured. Initially, bone sialoprotein (BSP) was immunolocalized on tissue sections of periodontium and on cultured cells to distinguish mineral‐forming cells from fibroblasts. Proteins were extracted from these cells to assess ALP activity by using an enzyme assay. RNA was extracted from the same cell source to detect ALP mRNA by reverse transcriptase polymerase chain reaction (RT‐PCR).Results: Cultured PDL/gingival fibroblasts were spindle shaped. Osteoblasts were irregularly shaped, and cell clusters/nodules were observed as they approached confluence. The cementoblasts manifested a polygonal shape and had two morphotypes: osteoblast‐like and cuboidal or stratified. BSP was localized within the mineralized tissues and in osteoblasts and cementoblasts in culture and in tissue sections. The highest level of ALP activity was found in osteoblasts, a moderate level in PDL fibroblasts, and the lowest level in gingival fibroblasts. The cementoblasts lacked ALP activity, and this was reflected by a very weak signal (or no signal at all) for ALP mRNA in the cementoblasts.Conclusions: These studies indicate that cells consistent with a cementoblast‐like phenotype may be successfully cultured, and that they lack ALP activity. J Periodontol 1999;70:951‐959.
Periodontal Tissue Disposition of Azithromycin in Patients Affected by Chronic Inflammatory Periodontal Diseases
Authors: Blandizzi Corrado , Malizia Tecla , Lupetti Antonella , Pesce Diego , Gabriele Mario , Giuca Maria R. , Campa Mario , Tacca Mario Del , Senesi Sonia 
Published: February 2005

Background: The recognition that periodontal diseases are associated with specific pathogens has led to interest in the use of antibacterial drugs for inhibition of these microorganisms. On these bases, the present study was aimed at evaluating the tissue distribution of the new macrolide antibiotic azithromycin in patients subjected to oral surgery for chronic inflammatory diseases of both marginal and periapical periodontium.Methods: Thirty‐two patients were treated with azithromycin 500 mg/day orally for 3 consecutive days, and drug concentrations in plasma, saliva, normal gingiva, and pathological periodontal tissues were evaluated. For this purpose, samples of blood, saliva, normal gingiva, granulation tissue, and radicular granuloma or cyst wall (from dentigerous cyst) were collected during oral surgery or 0.5, 2.5, 4.5, and 6.5 days after the end of pharmacological treatment; then, azithromycin levels were measured by a microbiological plate assay, using Micrococcus luteus NCTC 8440 as the indicator organism.Results: The concentrations of azithromycin in plasma, saliva, normal gingiva, and pathological tissues reached the highest values 12 hours after the last dose (0.37 ± 0.05 mg/l, 2.12 ± 0.30 mg/l, 6.30 ± 0.68 mg/kg, and 11.60 ± 1.50 mg/kg, respectively) and then declined gradually. Consistent levels of the drug in normal gingiva and pathological tissues could be detected, however, up to 6.5 days, indicating that azithromycin was retained in target tissues for a long time after the end of treatment. Moreover, azithromycin levels in both normal gingiva and pathological tissues exceeded the minimum inhibitory concentrations of most pathogens involved in the pathophysiology of chronic inflammatory periodontal diseases. Notably, azithromycin levels in pathological tissues were significantly higher than those in normal gingiva 0.5, 2.5, and 4.5 days after the last dose.Conclusions: The present results indicate a marked penetration of azithromycin into both normal and pathological periodontal tissues, suggesting that azithromycin represents a promising option in both adjunctive and prophylactic treatments of chronic inflammatory periodontal diseases. J Periodontol 1999;70:960‐966.
Enhanced Production of Mineralized Nodules and Collagenous Proteins In Vitro by Calcium Ascorbate Supplemented With Vitamin C Metabolites
Authors: Rowe Dorothy J. , Ko Susan , Tom Xenia M. , Silverstein Steven J. , Richards David W. 
Published: February 2005

Background: Vitamin C or ascorbate is important in wound healing due to its essential role in collagen synthesis. To study wound healing in the periodontium, cells adherent to expanded polytetrafluoroethylene (ePTFE) augmentation membranes, recovered from edentulous ridge augmentation procedures, have been established in culture in our laboratories. The objective of this study was to determine whether treatment of these cells with a calcium ascorbate, which contains vitamin C metabolites (metabolite‐supplemented ascorbate), would increase the production of collagenous protein and mineralized tissue in vitro, as compared to unsupplemented calcium ascorbate (ascorbate).Methods: Cells derived from ePTFE membranes were cultured with β‐glycerophosphate and the test agents for 2 to 5 weeks, and the surface areas of the cell cultures occupied by mineralized nodules were measured using computerized image analysis. One experiment tested the effects of calcium threonate, one of the vitamin C metabolites in metabolite‐supplemented ascorbate. Incorporation of radioactive praline and glycine was used as a measure of total protein (radioactivity precipitated by trichloracetic acid) and collagenase‐digestible protein (radioactivity released by collagenase digestion.) Co‐localization of collagen and fibronectin was examined by immunofluorescence.Results: In vitro treatment of these cells with metabolite‐supplemented ascorbate increased the area of The cell cultures occupied by mineralized nodules after 5 weeks. Cell cultures treated with metabolite‐supplemented ascorbate also exhibited significant increases in total protein. The increase in collagenous proteins in these cultures accounted for 85% of the increase in total protein. The greatest difference between treatment groups was observed in the cell‐associated fraction containing the extracellular matrix. The additional collagen exhibited normal co‐distribution with fibronectin. In cultures treated with ascorbate spiked with calcium threonate, the area of mineralized tissue was significantly greater than in ascorbate‐treated cultures, but was less than the observed in cultures treated with metabolite‐supplemented ascorbate.Conclusions: In vitro treatment with ascorbate containing vitamin C metabolites enhanced the formation of the mineralized nodules and collagenous proteins. Calcium threonate may be one of the metabolites influencing the mineralization process. Identifying factors which facilitates the formation of mineralized tissue has significant clinical ramifications in terms of wound healing and bone regeneration.J Periodontal 1999:70:992‐999
Chronic Ulcerative Stomatitis: A Case Report
Authors: Lorenzana Eduardo R. , Rees Terry D. , Glass Marcia , Detweiler Jeffrey G. 
Published: February 2005

Background: Certain mucocutaneous diseases present with painful, ulcerative, or erosive oral manifestations. Chronic ulcerative stomatitis is a newly recognized disease of unknown origin which presents clinically with features of desquamative gingivitis. This report marks only the thirteenth case reported in the world literature. A review of previous reports and studies is presented along with a review of immunofluorescence techniques critical to proper diagnosis. These diseases are difficult to diagnose without the use of immunofluorescence techniques. A 54‐year‐old Caucasian woman presented with a 2‐ to 3‐year history of stomatitis and dry mouth.
Methods: Direct immunofluorescence revealed a speckled pattern of IgG deposits in the basal one‐third of the epithelium, while indirect immunofluorescence confirmed the presence of stratified epithelium‐specific antinuclear antigen (SES‐ANA), both pathognomonic for chronic ulcerative stomatitis.
Results: The patient was successfully treated using topical corticosteroid therapy. J Periodontol 2000;71:104‐111.
Enamel Matrix‐Derived Protein Stimulates Attachment of Periodontal Ligament Fibroblasts and Enhances Alkaline Phosphatase Activity and Transforming Growth Factor β1 Release of Periodontal Ligament and Gingival Fibroblasts
Authors: Van der Pauw Monique T. , Van den Bos Theo , Everts Vincent , Beertsen Wouter 
Published: February 2005

Background: Although it is claimed that enamel matrixderived proteins (EMP) can be used to promote new attachment formation around periodontally involved teeth, the underlying biological mechanism is not understood. It was the aim of the present study to investigate the effects of EMP on the behavior of human periodontal ligament (HPLF) and gingival fibroblasts (HGF) in vitro, with special focus on their attachment properties, the expression of alkaline phosphatase (ALP) activity, the release of transforming growth factor (TGF)β1, and their proliferative rate.Methods: Fibroblast populations were obtained from 10 individuals with a healthy periodontium and cultured in chemically defined medium on culture plates coated with EMP, purified collagen type I, or their respective vehicles. Experiments were performed in the absence of serum for periods up to 48 hours.Results: It was shown that HGF barely attached and spread on EMP‐coated substrata, whereas HPLF attached and spread within 24 hours. However, when cultured on purified collagen type I, both cell types showed rapid attachment and spreading. Furthermore, the expression of ALP activity was significantly enhanced under the influence of EMP, especially in HPLF. HPLF and HGF both released significantly higher levels of TGFβ1 in the presence of EMP. EMP did not influence 3H‐thymidine incorporation by HPLF and HGF.Conclusions: Our results indicate that HPLF and HGF respond differently to EMP. A more rapid attachment of HPLF to this substratum might contribute, during the initial stages of periodontal healing, to selective outgrowth and colonization of exposed root surfaces in vivo. J Periodontol 2000;71:31‐43.
Immunolocalization of c‐Myc and bcl‐2 Proto‐Oncogene Products in Gingival Hyperplasia Induced by Nifedipine and Phenytoin
Authors: Saito Keiichi , Mori Shiro , Tanda Naoko , Sakamoto Seizaburo 
Published: February 2005

Background: Hyperplastic gingival tissues show the histopathological characteristics of thick parakeratinized squamous epithelia with acanthosis and rete pegs elongated into the lamina propria. However, the pathogenic factors that contribute to the epithelial morphogenesis of this disease are obscure and remain to be studied.Methods: We immunohistochemically examined the expression of both c‐Myc and bcl‐2 oncoprotein, which can exert influence on the epithelial morphogenesis and homeostasis, in 12 hyperplastic gingival tissues induced by nifedipine and phenytoin as well as 5 control tissues using avidin‐biotin‐peroxidase complex methods.Results: Four specimens out of 5 nifedipine‐induced and 5 out of 7 phenytoin‐induced hyperplastic gingival tissues revealed the expression of c‐Myc oncoprotein, whereas no significant immunostaining of c‐Myc oncoprotein was found in 5 control tissues. The c‐Myc oncoprotein‐positive cells were observed to be localized in the basal and suprabasal cell layers of the hyperplastic gingival epithelia. Although all of the 12 hyperplastic gingival epithelia showed the distribution of bcl‐2 oncoprotein in the basal and suprabasal layer cells, in 5 control epithelia the bcl‐2 oncoprotein expression was slight and confined to the basal layer cells.Conclusions: The results of our present study indicate that the synergistic overexpression of c‐Myc and bcl‐2 oncoprotein may be related to the pathogenesis of gingival hyperplasia induced by nifedipine and phenytoin, especially to the morphogenesis of hyperplastic epithelia. J Periodontol 2000;71:44‐49.
Employing a Transgenic Animal Model to Obtain Cementoblasts In Vitro
Authors: D'Errico John A. , Berry Janice E. , Ouyang Hongjiao , Strayhorn Christopher L. , Windle Jolene J. , Somerman Martha J. 
Published: February 2005

Background: Proper formation of cementum, a mineralized tissue lining the tooth root surface, is required for development of a functional periodontal ligament. Further, the presence of healthy cementum is considered to be an important criterion for predictable restoration of periodontal tissues lost as a consequence of disease. Despite the significance of cementum to general oral health, the mechanisms controlling development and regeneration of this tissue are not well understood and research has been hampered by the lack of adequate in vitro experimental models.Methods: In an effort to establish cementoblast cell populations, without the trappings of a heterogeneous population containing periodontal ligament (PDL) cells, cells were obtained from the root surface of first mandibular molars of OC‐TAg transgenic mice. These mice contain the SV40 large T‐antigen (TAg) under control of the osteocalcin (OC) promoter. Therefore, only cells that express OC also express TAg and are immortalized in vitro. Based on results of prior in situ studies, OC is expressed by cementoblasts during root development, but not by cells within the PDL. Consequently, when populations are isolated from developing molars using collagenase/trypsin digestion, only cementoblasts, not PDL cells, are immortalized and thus, will survive in culture.Results: The resulting immortalized cementoblast population (OC/CM) expressed bone sialoprotein (BSP), osteopontin (OPN), and OC, markers selective to cells lining the root surface. These cells also expressed type I and XII collagen and type I PTH/PTHrP receptor (PTH1R). In addition to expression of genes associated with cementoblasts, OC/CM cells promoted mineral nodule formation and exhibited a PTHrP mediated cAMP response.Conclusions: This approach for establishing cementoblasts in vitro provides a model to study cementogenesis as required to enhance our knowledge of the mechanisms controlling development, maintenance, and regeneration of periodontal tissues. J Periodontol 2000;71:63‐72.
Effect of Cigarette Smoking on Periodontal Status of Healthy Young Adults
Authors: Machuca Guillermo , Rosales Isabel , Lacalle Juan R. , Machuca Carmen , Bullón Pedro 
Published: February 2005

Background: It has been shown that tobacco is a significant risk factor for periodontal disease; however, there have been few studies on young populations where problems of general health can be discounted. The purpose of this study was to examine the influence of tobacco consumption on the periodontal condition of a young, healthy population.Methods: The study population consisted of 304 young Caucasian males (average age 19.38 ± 0.72 years) entering the Armed Forces. All the subjects completed a self‐administered questionnaire on age, oral hygiene habits, previous dental examinations, and quantity and length of tobacco use. The periodontal examination consisted of the plaque index (PI); periodontal bleeding index (PBl); probing depth (PD); and clinical attachment level (CAL). One‐ and 2‐way ANOVA was used to compare data recorded between smokers and nonsmokers.Results: Forty‐six percent of subjects reported that they brushed their teeth at least once a day, but only 13% visited a dentist at least once a year. Over half (53%) were habitual smokers, 43% smoking between 5 and 20 cigarettes per day; 39% of the smokers had been smoking for less than 5 years. Mean Pl was 31.24 ± 14.88 (27.19 ± 15.93 for smokers and 35.78 ± 12.17 for non‐smokers), with significant differences between non‐smokers and those who smoked 5 to 20 cigarettes per day (26.85 ± 16.11, P <0.0001). Mean PBl was 42.29 ± 8.43 (non‐smokers 44.67 ± 6.53 and smokers 40.17 ± 9.46). Significant differences were found between the PBl of the non‐smokers and of those who smoked 5 to 20 cigarettes per day (39.90 ± 9.64, P <0.0001). There were also differences in the PBl between those who brushed their teeth once (40.53 ± 9.61) and twice (44.86 ± 5.9) a day (P <0.0001). Mean PD was 1.62 ± 0.43 mm (non‐smokers 1.56 ± 0.36 and smokers 1.68 ± 0.49). Deeper probing depths were recorded among smokers than among non‐smokers, with statistically significant differences (P <0.049); statistically significant differences were also found between those who attended (1.49 ± 0.50) and those who did not attend (1.65 ± 0.42) regular dental check‐ups (P <0.031). Mean CAL 1.75 ± 0.41 (non‐smokers 1.64 ± 0.32 and smokers 1.82 ± 0.44).Conclusions: It may be concluded that, even at such an early age, tobacco consumption affects the periodontal health. It is necessary to inform young smokers of the risk of tobacco use regarding periodontal health. J Periodontol 2000;71:73‐78.
Periodontal Probing: Probe Tip Diameter
Authors: Garnick Jerry J. , Silverstein Lee 
Published: February 2005

Background: Periodontal probing is one of the most common methods used in diagnosing periodontal disease. The purpose of this study was to determine the importance of the diameter of periodontal probing tips in diagnosing and evaluating periodontal disease.
Methods: The literature discussing periodontal probe diameters in human, dog, and monkey studies was reviewed and compared. Tip diameters varied from 0.4 to over 1.0 mm in these studies. Probe advancement between the gingiva and the tooth is determined by the pressure exerted on the gingival tissues and resistance from the healthy or inflamed tissue. The pressure is directly proportionate to the force on the probe and inversely proportionate to the probe tip diameter. The larger probing diameters reduced probe advancement into inflamed connective tissue. This effect of change in probe diameter reduced the pressure in a greater manner than an increase of similar change in probe force.
Results: In the studies reviewed, the pressure used to place the probe tip at the base of the periodontal sulcus/pocket was approximately 50 N/cm2 and at the base of the junctional epithelium, 200 N/cm2. A tip diameter of 0.6 mm was needed to reach the base of the pocket. Clinical inflammation did not necessarily reflect the severity of histological inflammation, and the recordings may not illustrate probing depth. Furthermore, probing depth did not identify anatomical locations at the base of the pocket.
Conclusions: Probe tips need to have a diameter of 0.6 mm and a 0.20 gram force (50 N/cm2) to obtain a pressure which demonstrates approximate probing depth. This pressure was needed to measure the reduction of clinical probing depth, which included formation of a long junctional epithelium as a result of therapy. In addition, different forces or diameter tips are needed to measure healthy or inflamed histological periodontal probing depths. J Periodontol 2000;71:96‐103.
Periodontal Disease Progression
Authors: Reddy Michael S. , Geurs Nico C. , Jeffcoat Robert L. , Proskin Howard , Jeffcoat Marjorie K. 
Published: February 2005

Background: The objective of this investigation is to use noninvasive, state‐of‐the‐art, diagnostic techniques to measure periodontal disease progression and model periodontal disease activity over time. In this investigation, digital subtraction radiography and an electronic controlled force periodontal probe capable of attachment level measurement were used to measure bone loss and attachment loss, respectively. The use of these nearly continuous measures of attachment and bone loss allowed detection of small amounts of disease activity and provided data to be used in modeling of the disease process over time.Methods: Forty‐four patients were studied for 18 months. Examinations used clinical attachment level measures at 1‐month intervals and quantitative radiology at 6‐month intervals. The sites were analyzed by regression for statistically significant changes. These data were used to determine sites of periodontal disease activity for testing various models of periodontal disease progression.Results: Overall 22.8% of sites lost attachment, 5.4% gained, and 71.7% demonstrated no statistically significant change. The mean time to lose 1 mm of attachment was 8.4 ± 0.6 months. In the first model tested a step‐wise discriminant analysis was used to determine whether or not baseline measurements of plaque (PI), gingival inflammation (GI), attachment loss, and probing depth (PD) could be used to derive a satisfactory model for disease progression. Although the overall model was statistically significant with PI, PD, and GI contributing to the model (Wilks' lambda = 0.859, F = 5.71, P <0.0012), its predictive power was relatively weak. A considerably stronger significant model resulted when the rate of attachment loss over the first 6 months, baseline PI, and baseline GI were included (Wilks' lambda = 0.712, F = 14.17, P <0.00001). A significant model also resulted when bone loss during the first 6 months and baseline probing depth were included (Wilks' lambda = 0.438, F = 61.48, P <0.00001). When the last model was applied to each site, the sensitivity in predicting disease progression was 80.0% and the specificity in ruling out progressive disease was 93.9%.Conclusions: This study indicates that clinically significant progression of attachment loss in posterior tooth sites occurs as a frequent event in adult periodontitis. The modeling data also suggest that short‐term (6 month) measures of periodontal disease progression greatly improve the ability to model attachment loss over a longer period in untreated periodontitis patients. J Periodontol 2000;71:1583‐1590.
Growth Factors Regulate Expression of Mineral Associated Genes in Cementoblasts
Authors: Saygin N. Esra , Tokiyasu Yoshihiko , Giannobile William V. , Somerman Martha J. 
Published: February 2005

Background: Knowledge of the responsiveness of cells within the periodontal region to specific bioactive agents is important for improving regenerative therapies. The aim of this study was to determine the effect of specific growth factors, insulin‐like growth factor‐I (IGF‐I), platelet‐derived growth factor‐BB (PDGFBB), and transforming growth factor‐β (TGF‐β) on cementoblasts in vitro and ex vivo.Methods: Osteocalcin (OC) promoter driven SV40 transgenic mice were used to obtain immortalized cementoblasts. Growth factor effects on DNA synthesis were assayed by [3H]‐thymidine incorporation. Northern analysis was used to determine the effects of growth factors on gene expression profile. Effects of growth factors on cementoblast induced biomineralization were determined in vitro (von Kossa stain) and ex vivo (re‐implantation of cells in immunodeficient (SCID) mice).Results: All growth factors stimulated DNA synthesis compared to control. Twenty‐four hour exposure of cells to PDGFBB or TGF‐β resulted in a decrease in bone sialoprotein (BSP) and osteocalcin (OCN) mRNAs while PDGF‐BB also increased osteopontin (OPN) mRNA. Cells exposed to IGF‐I for 24 hours exhibited decreased transcripts for OCN and OPN with an upregulation of BSP mRNA noted at 72 hours. In vitro mineralization was inhibited by continuous application of PDGF‐BB or TGF‐β, while cells exposed to these factors prior to implantation into SCID mice still promoted biomineralization.Conclusions: These data indicate IGF‐I, PDGF‐BB, and TGF‐β influence mitogenesis, phenotypic gene expression profile, and biomineralization potential of cementoblasts suggesting that such factors alone or in combination with other agents may provide trigger factors required for regenerating periodontal tissues. J Periodontol 2000;71:1591‐1600.