bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Repeated Local Minocycline Administration on Periodontal Healing Following Guided Tissue Regeneration
Authors: Yoshinari Nobuo , Tohya Tosyo , Kawase Hitoshi , Matsuoka Masanori , Nakane Mitsuo , Nakane Mitsuo , Mitani Akio , Koide Masanori , Inagaki Koji , Fukuda Mitsuo , Noguchi Toshihide 
Published: February 2005

Background: Infection after a periodontal surgical site has been prepared for guided tissue regeneration (GTR) is one of the common complications that can compromise healing. The purpose of this study was assess the effect of repeated local antimicrobial therapy following GTR for improving clinical attachment gains, and to histologically evaluate the various cell populations and bacterial contamination of the retrieved expanded polytetrafluoroethylene membrane (ePTFE).Methods: Forty periodontal intrabony defects in 40 patients were treated by a flap procedure that included the use of ePTFE membranes to allow GTR. Patients were randomly assigned to 2 treatment groups: 20 patients were treated with the ePTFE alone (control group), and the other 20 were treated with the ePTFE combined with the administration of a weekly repeated local application of minocycline ointment for 8 weeks after membrane placement (test group). The membranes were retrieved 6 weeks after the initial surgery and sectioned serially in a coronal‐apical plane. The sections were then divided into 9 fields and examined by light microscopy for the presence of inflammatory cells and oral bacteria. Clinical measurements were taken at the time of baseline examination and at a 6 month follow‐up examination after removal of the ePTFE.Results: At the 6‐month follow‐up examination, control and test groups showed significant improvement; i.e., reduction in the probing depth and increased clinical attachment gain compared with the values at the baseline examination. However, the mean clinical attachment gain of the test group (3.0 ± 0.3 mm) was significantly (P = 0.03) greater than that of the control group (2.0 ± 0.5 mm). Histologically, the total number of the cells of both groups was similar. In both groups, mononuclear cells were dominant and fibroblasts, neutrophils, and plasma cells were rarely encountered. There was a tendency for the number of macrophages to be somewhat higher in the control group. The total number of bacteria in the test group was significantly less than that in the control group. The number of bacteria in both control and test groups decreased toward the apical portion.Conclusions: In the present study, clinical attachment gain of intrabony defects following GTR was favorable with repeated local administration of minocycline ointment. However, a complete microbial eradication was not achieved. J Periodontol 2001;72:284‐295.
Comparison of Calcium Sulfate and Autogenous Bone Graft to Bioabsorbable Membranes Plus Autogenous Bone Graft in the Treatment of Intrabony Periodontal Defects: A Split‐Mouth Study
Authors: Orsini Marco , Orsini Giovanna , Benlloch Dunia , Aranda Juan Jose , Lazaro Pedro , Sanz Mariano , De Luca Massimo , Piattelli Adriano 
Published: February 2005

Background: Current literature shows that calcium sulfate can be used in guided tissue regeneration. Its biocompatibility and resorbability give it significant advantages in the treatment of periodontal and endodontic defects. Clinically guided tissue regeneration procedures have demonstrated significant positive clinical change, beyond that achieved with debridement alone, in treating intraosseous defects. The aim of the present investigation was to evaluate the clinical results obtained with autologous bone plus calcium sulfate, and to compare them with the results obtained using autologous bone plus membrane.Methods: A total of 12 patients were treated in the present investigation. A split‐mouth design was utilized. Twelve 3‐wall periodontal defects were treated with calcium sulfate plus autologous bone graft (test) and compared with 12 contra‐lateral defects treated with a bioabsorbable membrane plus autologous bone graft (control). Before the surgical procedure, patients were instructed about oral hygiene and scaling and root planing (SRP) was completed. Probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were recorded at baseline and 6 months.Results: There were no statistical differences between test and control defects at baseline. BOP was 58% and 50% for control and test defects, respectively. Mean PD was 7.75 ± 0.96 mm (control) and 8.0 ± 1.28 mnn (test). Mean CAL was 8.58 ± 1.31 mm (control) and 8.83 ± 0.91 mm (test). At 6 months, mean PD was 3.41 ± 0.51 (P = 0.0022) for control defects and 3.58 ± 0.51 (P = 0.0022) for test defects. CAL showed a mean gain of 5 ± 0.85 for controls (P = 0.0022) and 5.25 ± 0.75 for test defects (P = 0.0022). Thus, there was a mean reduction of PD of 4.33 mm (56%) for control sites and 4.42 mm (55%) for test sites. The mean clinical attachment gain was 3.57 mm for control sites and 3.58 mm for test sites. As there were no shamoperated controls, it is not clear that the healing of these test or control‐treated sites was any better than similar 3‐walled defects sham operated.Conclusions: Both therapies led to short‐term improvement of the measured parameters; neither was superior to the other. J Periodontol 2001;72:296‐302.
Thrombin‐Stimulated Growth, Clustering, and Collagen Lattice Contraction of Human Gingival Fibroblasts Is Associated With Its Protease Activity
Authors: Chang Mei‐Chi , Chan Chiu‐Po , Wu Hui‐Lin , Chen Ruey‐Song , Lan Wan‐Hong , Chen Yi‐Jane , Jeng Jiiang‐Huei 
Published: February 2005

Background: Thrombin is a serine protease produced following gingival tissue injury or inflammation. It regulates the functional behavior of injury‐neighboring cells via the activation of specific protease‐activated receptors (PAR). Thrombin's role in gingival tissue healing and inflammatory response processes is not yet well understood.Methods: We investigated the effects of thrombin on gingival fibroblast (GF) growth [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐tetrazolium bromide (MTT) assay], collagen lattice contraction, and associated morphological changes.Results: Thrombin (>1 U/ml), but not thrombin receptor (PAR‐1) agonist peptide (SFLLRN, single letter amino acid code, abbreviated as TRAP, 1 to 50 μg/ml), stimulated the growth and clustering of cultured human GF in vitro. Growth‐stimulatory effects of thrombin were inhibited by D‐Phe‐Pro‐ArgCH2Cl (PPACK), a serine protease inhibitor. By contrast, trypsin (>10 μg/ml), a PAR‐2 activator, suppressed the growth of GF. Thrombin (>0.2 U/ml) and TRAP (10 to 25 μg/ml), but not trypsin, prostaglandin E2 (0.01 to 0.5 μg/ml), or bovine serum albumin (BSA) (1 to 80 μg/ml), induced the GF‐populated collagen lattice contraction within 30 to 60 minutes of exposure. The thrombin‐induced collagen lattice contraction was inhibited by PPACK (20 μg/ml) and an actin filament polymerization inhibitor, cytochalasin B (1 μg/ml). The collagen lattice contraction induced by TRAP was also inhibited by cytochalasin B, but not by PPACK. Using a reversetranscriptase polymerase chain reaction (RT‐PCR), the expression of PAR‐1, and to a lesser extent PAR‐3, was observed for human GF, although little PAR‐2 and PAR‐4 expression was noted.Conclusions: These results indicate that thrombin is important in periodontal wound healing and inflammatory processes by promoting the growth and contraction of GF. The stimulatory effects of thrombin are associated with its protease activation of thrombin receptors. J Periodontol 2001;72:303‐313.
Participation of Periodontal Ligament Cells With Regeneration of Alveolar Bone
Authors: Isaka Jun , Ohazama Atsushi , Kobayashi Makoto , Nagashima Chizu , Takiguchi Takashi , Kawasaki Hideyuki , Tachikawa Tetsuhiko , Hasegawa Kohji 
Published: February 2005

Background: It is important to clarify the participation of periodontal ligament (PDL) cells in the regeneration of alveolar bone to establish a reliable approach for obtaining periodontal regeneration. The aim of this study was to determine whether PDL cells play an important role in alveolar bone repair during the course of periodontal regeneration.Methods: In an in vitro study, the expression of the osteoblast phenotype, such as alkaline phosphatase activity and parathyroid hormone‐dependent 3′,5′‐cyclic adenosine monophosphate accumulation, was investigated in dog PDL cells (DPLC) and dog bone cells isolated from mandibles (DBC). In a related study, the roots of mandibular third premolars extracted from aged dogs were divided into a PDL(+) group, in which the PDL was preserved, and a PDL(‐) group, in which the PDL was removed. These roots were respectively transplanted into surgically created bone cavities with buccal and interproximal bone defects in an edentulous area, prepared in advance by extraction of mandibular fourth premolars. These bone defects with the transplanted roots were completely covered with submerged physical barrier membranes. New bone formation and new connective tissue attachment, which require new cementum and insertion of functionally oriented new collagen fibers of periodontal ligament, were histomorphometrically assessed, and were compared between the PDL(+) and PDL(‐) groups 6 weeks after transplantation.Results: Both cultured DPLC and DBC exhibited the osteoblast phenotype. New connective tissue attachment was observed only in the PDL(+) group. However, alveolar bone was almost completely regenerated to the original bone height in both the PDL(+) and PDL(‐) groups, and the amount of newly formed bone was not significantly different between the 2 groups.Conclusions: DPLC retain the capability to differentiate into an osteoblast lineage and may act in the regeneration of periodontal ligament with new cementum formation, whereas these cells may have a limited influence on alveolar bone formation during the course of periodontal regeneration. J Periodontol 2001;72:314‐323.
Characterization of Proliferation and Cellular Wound Fill in Periodontal Cells Using an In Vitro Wound Model
Authors: Oates Thomas W. , Mumford John H. , Carnes David L. , Cochran David L. 
Published: February 2005

Background: The therapeutic success of periodontal regenerative therapy may be compromised by our limited understanding of the wound healing process. Wound healing requires the coordination of complex cellular and molecular interactions. Recently, using an in vitro wound model, our laboratory has shown that gingival fibroblasts (GF) fill an in vitro wound more rapidly than periodontal ligament cells (PDL). This suggests that there may be differences in the levels of proliferation for these 2 cell types during the wound healing process. Such specific cell type differences may be significant in clinical outcomes of regenerative therapy. Therefore, the aim of this research was to characterize and compare the levels of both proliferation and cellular wound fill between GF and PDL using our in vitro wound model.Methods: Primary cultures of human PDL and GF cells were established from explanted tissue, and passaged to 12‐well tissue culture plates. Triplicate cultures of both cell types were grown to confluence and in vitro wounds were mechanically created, removing a 3 mm wide band of the cell layer across the diameter of the wells. The wells were then incubated for 2, 6, or 9 days in media containing either 0.1% or 10% fetal bovine serum (FBS). At each time point, cells were pulsed with 5‐bromo, 2‐deoxyuridine (BrdU), fixed, and nuclei stained to measure DNA synthesis (as a measure for proliferation). Cells were counter stained with cytoplasmic stain to measure cell number. Quantitative analysis distant from (area of interest [AOI 1]), next to (AOI 2), and within the wound boundaries (AOI 3 and 4) was accomplished using computer‐assisted histomorphometry.Results: The levels of proliferation and cellular fill for each cell type were assessed relative to time and AOI. Overall, the PDL displayed greater (P <0.01) levels of proliferation than the GF. For both cell types, proliferation was found to be significantly (P <0.001) greater at day 2 compared to other time points. PDL displayed greater levels of proliferation than GF in all AOI, with this difference reaching significance (P <0.02) within the cell layer (AOI 1 and 2). When comparing levels of cellular fill in 10% FBS, GF displayed greater wound fill than the PDL. This difference was significant at day 6 (P <0.05) for both the marginal (AOI 3) and central (AOI 4) portions of the wound.Conclusions: These findings, demonstrating unique differences between PDL and GF with respect to proliferation and wound fill in an in vitro model, suggest that there may be cell‐specific differences in cellular activity critical to periodontal wound healing. In addition, the results of this study show that the cellular proliferation response may not accurately reflect the overall wound healing response. J Periodontol 2001;72:324‐330.
Enamel Matrix Derivative Induces Matrix Synthesis by Cultured Human Periodontal Fibroblast Cells
Authors: Haase H.R. , Bartold P.M. 
Published: February 2005

Background: Periodontal wound healing and regeneration require that new matrix be synthesized, creating an environment into which cells can migrate. One agent which has been described as promoting periodontal regeneration is an enamel matrix protein derivative (EMD). Since no specific growth factors have been identified in EMD preparations, it is postulated that EMD acts as a matrix enhancement factor. This study was designed to investigate the effect of EMD in vitro on matrix synthesis by cultured periodontal fibroblasts.Methods: The matrix response of the cells was evaluated by determination of the total proteoglycan synthesis, glycosaminoglycan profile, and hyaluronan synthesis by the uptake of radiolabeled precursors. The response of the individual proteoglycans, versican, decorin, and biglycan were examined at the mRNA level by Northern blot analysis. Hyaluronan synthesis was probed by identifying the isotypes of hyaluronan synthase (HAS) expressed in periodontal fibroblasts as HAS‐2 and HAS‐3 and the effect of EMD on the levels of mRNA for each enzyme was monitored by reverse transcription polymerase chain reaction (RTPCR). Comparisons were made between gingival fibroblast (GF) cells and periodontal ligament (PDLF) cells.Results: EMD was found to significantly affect the synthesis of the mRNAs for the matrix proteoglycans versican, biglycan, and decorin, producing a response similar to, but potentially greater than, mitogenic cytokines. EMD also stimulated hyaluronan synthesis in both GF and PDLF cells. Although mRNA for HAS‐2 was elevated in GF after exposure to EMD, the PDLF did not show a similar response. Therefore, the point at which the stimulation of hyaluronan becomes effective may not be at the level of stimulation of the mRNA for hyaluronan synthase, but, rather, at a later point in the pathway of regulation of hyaluronan synthesis. In all cases, GF cells appeared to be more responsive to EMD than PDLF cells in vitro.Conclusions: EMD has the potential to significantly modulate matrix synthesis in a manner consistent with early regenerative events. J Periodontol 2001;72:341‐348.
Is Loss of Attachment Due to Root Planing and Scaling in Sites With Minimal Probing Depths a Statistical or Real Occurrence?
Authors: Gunsolley John C. , Yeung Gabriel M. , Butler James H. , Waldrop Thomas C. 
Published: February 2005

Background: Following root planing and scaling many studies have implied an association between a loss of clinical attachment at sites with initially shallow pockets (1 to 3 mm) and gains in attachment level for deeper probing depths. However, these effects are also consistent with a statistical phenomenon referred to as regression towards the mean. This principle suggests that extreme values will moderate the next time they are recorded. The purpose of this report was to estimate the effect that regression towards the mean has on perceived changes in attachment level after root planing and scaling.Methods: During the initial examination, 2 different investigators conducted 2 full‐mouth probings. Two quadrants were randomly selected to be root planed and scaled until the root surfaces were smooth by tactile touch of an explorer. The 2 remaining quadrants were not treated. At 4 to 6 weeks after treatment, another full mouth probing was done. An examiner who was blind to the quadrants that had been scaled measured attachment level and probing depth after therapy. This study design provided periodontal measurements before and after root planing and scaling, measurements before and after a period of 4 to 6 weeks of no therapy, and duplicate measurements at the beginning of the study.Results: Using the repeat examination when no true change could occur, shallow sites (≤3 mm of probing depth) showed average negative differences between repeat attachment level measurements (‐0.23 mm), which mimicked loss of periodontal attachment. Deep sites, (>6 mm) showed average positive values (0.40) mimicking gain in attachment level. These results suggest that regression towards the mean is a significant effect in this data set. Both shallow non‐scaled and scaled sites had similar differences in repeat measures (‐0.28 mm, ‐0.25 mm) which were also similar to and not statistically different from changes after therapy for both non‐scaled (‐0.21 mm) and scaled sites (‐0.08 mm). Thus not only does this data set exhibit regression towards the mean, but it explains the majority of perceived loss of periodontal attachment after scaling at sites that have minimal probing depth.Conclusions: These results suggest that the majority of perceived loss of attachment due to scaling at sites of minimal probing depth that have been reported in many studies may be due a statistical phenomenon called regression towards the mean. J Periodontol 2001;72:349‐353.
Dental Unit Waterline Contamination and Its Possible Implications During Periodontal Surgery
Authors: Putnins Edward E. , Di Giovanni Davide , Bhullar Amandeep S. 
Published: February 2005

Background: Dental unit waterline contamination has become a concern to clinical dentistry. This concern arises from the fact that bacteria sloughed from established biofilms in dental unit waterlines increase heterotrophic bacteria counts in water exiting these units.Methods: Scanning microscopy and bacterial viability staining were used to examine the sessile and planktonic biofilm present in dental unit waterlines and water samples, respectively. In addition, the limulus amebocyte assay was used to measure the lipopolysaccharide (LPS) levels in water samples.Results: All dental unit waterlines were coated with a wellestablished biofilm made up of filamentous and bacillus‐like microorganisms. Water samples collected from these dental units contained high numbers of individual bacteria and bacterial aggregates. A viability staining technique identified signifi‐cantly more bacteria in water than could be cultured, and 64% of the total bacterial population stained as nonvital. Since the bacterial load (viable and nonviable) was high, we examined the LPS in dental unit water samples. The mean LPS levels in water collected from high‐speed and air/water lines in use were 480 and 1,008 endotoxin units (EU)/ml. This was significantly higher than the mean level of 66 EU/ml found in water samples collected from adjacent clinic sinks. The LPS level at the start of the day (2,560 EU/ml) was reduced by 70% with 1 minute of flushing (800 EU/ml). Flushing times of 5 and 10 minutes were not able to reduce LPS levels to zero.Conclusion: The presence of high heterotrophic bacterial counts, sloughing biofilm, and high LPS levels are discussed in relation to patient risk and periodontal wound healing biology. J Periodontol 2001;72:393‐400.
Evaluation of Ultrasonic Scaling Unit Waterline Contamination After Use of Chlorine Dioxide Mouthrinse Lavage
Authors: Wirthlin M. Robert , Marshall Grayson W. 
Published: February 2005

Background: An infection control problem in dental operatories which is not fully controlled is waterline contamination by heterotrophic mesophilic bacteria. These bacteria are present in water supplies as a planktonic phase and adhere to the lumen of tubings as a biofilm comprised of their external cell surface glycocalyx and by production of extracellular carbohydrate polymers. The adherent film is most difficult to remove. The accumulated planktonic phase can be reduced significantly by flushing water from the lines before use in patient treatment, but will return when the equipment is idle through the accumulation of more planktonic phase and by slough of the biofilm surface‐adsorbed phase not yet enmeshed in the carbohydrate matrix. Chlorine dioxide has antimicrobial activity against many bacteria, spores, and viruses. It is used in water supply treatment as a disinfectant and slime preventive and has an advantage over chlorine in that carcinogenic trihalomethanes are not generated.Methods: This study compared use of phosphate buffer‐stabilized chlorine dioxide (0.1%) mouthrinse as a lavage in ultrasonic dental scaler units with the use of tap water as a control. Sterile water flushed through the units onto heterotrophic plate count (HPC) sampler plates was cultured 7 days at room temperature and colonies were counted at 12×. One test and one control unit were used for biopsy of internal tubing and scanning electron microscopy imaging.Results: The HPC counts, in colony forming units (CFU)/ml, were reduced 3‐ to 5‐fold by flushing tap water through the units, but they returned after units were idle overnight. When phosphatebuffered chlorine dioxide mouthrinse was used as a lavage, CFU/ml were reduced 12‐ to 20‐fold. Holding chlorine dioxide in waterlines overnight reduced recurrent buildup compared to water (P <0.05). Scanning electron microscopy images indicated a significant reduction of biofilm coverage by chlorine dioxide as compared to water (P <0.001).Conclusions: Phosphate‐buffered chlorine dioxide mouthrinse was effective in these short‐term trials for control of waterline contamination in ultrasonic dental scaling units. It should prove as useful in dental professional waterline applications as it has in industrial uses for biofilm control. J Periodontol 2001;72:401‐410.
Effect of Nicotine on Fibroblast β1 Integrin Expression and Distribution In Vitro
Authors: Austin Gregory W. , Cuenin Michael F. , Hokett Steven D. , Peacock Mark E. , Sutherland Donald E. , Erbland John F. , Billman Michael A. 
Published: February 2005

Background: Integrins are a family of transmembrane cell surface glycoproteins, and those with the β1‐subunit function in both cell‐to‐cell and cell‐to‐substrate adhesion. The purpose of this study was to determine nicotine's effect on the expression and distribution of the β1 integrin subunit on the human gingival fibroblast cell surface.Methods: Pure nicotine was diluted in medium to the following concentrations: 0 (control), 0.025, 0.05, 0.1, 0.2, and 0.4 μM. Human gingival fibroblasts (HFG) were grown for 24 hours in each concentration and fluorescein‐labeled with a mouse monoclonal anti‐human β1 antibody and secondarily incubated with a urease‐labeled anti‐mouse IgG antibody. After a final wash, the cells were incubated with urea/bromcresol blue substrate for 15 minutes at 37°C and measured in a microplate reader at 570 nm.Results: The integrin β1‐subunit was detected on the HGF surface membrane by fluorescence labeling, and cell‐enzymelinked immunosorbent assay testing demonstrated its decreased expression with increasing nicotine concentrations that were statistically different at the concentrations of 0.2 and 0.4 μM versus controls (P <0.05).Conclusions: Nicotine concentrations of 0.2 and 0.4 μM significantly decrease β1 integrin expression in human gingival fibroblasts that may affect cell‐cell and cell‐substratum adhesion during wound healing. J Periodontol 2001;72:438‐444.