bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Vitro Evaluation of the Mitogenic Effect of Platelet‐Derived Growth Factor‐BB on Human Periodontal Ligament Cells Cultured with Various Bone Allografts
Authors: Papadopoulos C.E. , Dereka X.E. , Vavouraki E.N. , Vrotsos I.A. 
Published: February 2005

Background: Several studies have documented the role of growth factors in periodontal regeneration. It has been shown that platelet‐derived growth factor (PDGF) is a potent stimulator of human periodontal ligament (PDL) cells. A variety of bone graft materials are used to treat osseous defects caused by periodontal disease. We evaluated the mitogenic effect of PDGF on human PDL cells cultured with different allografts to determine which of the allografts with or without PDGF promoted periodontal regeneration.Methods: Two human demineralized freeze‐dried allografts of cortical (DFDBA) and cancellous (DFBA) bone and a non‐demineralized freeze‐dried allograft (FBA) from cancellous bone were used alone or supplemented with PDGF‐BB. Human PDL cultures were derived from the mid‐root of 2 maxillary premolars extracted for orthodontic reasons. Cells were grown separately in 24‐well dishes with or without 20 mg of each bone allograft. On day 2 of quiescence, new medium was added with 10 ng/ml of PDGFBB. DNA synthesis was estimated by measuring [3H] thymidine incorporation to determine the effects of the test agents on cell proliferation. Cells were processed and subjected to scintillation counting after 48 hours of incubation. Counts per minute (cpm/well) were determined for each sample.Results: There was no statistically significant difference (P <0.05) on PDL cell proliferation when the allografts were used alone. PDL cells exhibited significantly greater proliferative responses to the 2 demineralized bone allografts, DFDBA and DFBA, when combined with PDGF‐BB. A statistically significant difference on DNA synthesis was noticed when PDGF‐BB was added to PDL cells cultured with FBA. PDL cells displayed no significant increase in mitogenic activity when cultured with PDGF‐BB alone.Conclusions: The findings of this study demonstrate the beneficial role of DFDBA, DFBA, and FBA as synergic agents with PDGFBB to periodontal regeneration. The significant ability of the 2 decalcified bone allografts, DFDBA and DFBA, combined with PDGF to stimulate PDL cell proliferation might be a useful adjunct in the treatment of periodontal defects. J Periodontol 2003;74:451‐457.
Microvascular Response in the Periodontal Ligament Following Mucoperiosteal Flap Surgery
Authors: Nobuto Takahiro , Imai Hisao , Suwa Fumihiko , Kono Tomoo , Suga Hitoshi , Jyoshi Katuzi , Obayashi Kazuyoshi 
Published: February 2005

Background: When the mucoperiosteal flap is elevated, the gingivo‐periosteal vascular plexus and periodontal ligament (PDL) vascular plexus sever their connection with the circulatory tracts that pass through alveolar bone. We studied the effect exerted on the PDL vascular plexus during restoration of the circulatory tract.Methods: We performed experimental mucoperiosteal flap surgery in adult beagle dogs. Histological specimens, prepared after injecting India ink into the blood vessels on postoperative days 5, 7, 14, 21, 28, and 42, were examined under a light microscope. In addition, vascular corrosion cast specimens of the PDL, into which acrylic resin was injected, were observed using a scanning electron microscope.Results: On postoperative day 5, the PDL vascular plexus had formed new blood vessels toward the bone side and root side, and bone resorption of the alveolar bone proper had initiated primarily around the opening of the Volkmann's canal. From postoperative day 7 to 14, the PDL vascular plexus formed new vessels on the bone side and root side accompanied by bone resorption of the alveolus, and demonstrated a complicated vascular architecture, which gradually organized and transformed into a mesh structure from postoperative day 21. Osteogenesis was initiated and encircled the newly formed vessels, and the alveolar bone proper recovered to a flat morphology. Judging from the quantity of new vessels and bone resorption, the width of the PDL space seemed to be the greatest on postoperative day 14.Conclusions: When the mucoperiosteal flap was elevated, active wound healing was activated because of angiogenesis from the PDL, which possesses a microcirculatory system. Moreover, it was suggested that angiogenesis of the PDL vascular plexus and subsequent bone resorption of alveolar bone might temporarily reduce the tooth‐supporting function and cause postoperative mobility. J Periodontol 2003;74:521‐528.
Guided Bone Regeneration Around Titanium Plasma‐Sprayed, Acid‐Etched, and Hydroxyapatite‐Coated Implants in the Canine Model
Authors: Conner Kenneth A. , Sabatini Robert , Mealey Brian L. , Takacs Vincent J. , Mills Michael P. , Cochrann David L. 
Published: February 2005

Background: Endosseous dental implants with rough surfaces have been designed to improve early healing, especially in areas of poor bone or insufficient bone quantity. The aim of this study was to histomor‐ phometrically assess the bone‐to‐implant contact on 3 different rough‐surfaced implants following guided bone regeneration.Methods: Mandibulaf premolars and first molars were extracted in 12 dogs, and healing was allowed for 6 months. Six implant osteotomy sites were prepared, 3 per side, followed by the creation of 7.3 mm wide by 5 mm deep surgical defects in the coronal section of the osteotomy sites. Ten‐mm long titanium screw‐type implants with titanium plasma‐sprayed (TPS), hydroxyapatite‐coated (HA), or acid‐etched (AE) surfaces were placed; the surrounding defects were filled with canine demineralized freeze‐dried bone allograft: implants/grafts were covered with expanded polytetrafluoroethylene membranes; and the tissue was closed. Following a healing period of 4 months, the animals were sacrificed and mandibular blocks were harvested for histomorphometric analysis.Results: The mean percentage of bone‐to‐implant contact in the defect and non‐defect areas for the different implant surfaces was: AE 16.24% defect, and 28.78% non‐defect; TPS 25.08% defect, and 16.96% non‐defect; and HA 48.25% defect and 26.60% non‐defect. Within the defect, the mean difference in the bone‐to‐implant contact was significant for HA compared to TPS (P<0.0001) and HA versus AE (P<0.0001); TPS versus AE was not significant (P = 0.063). In the non‐defect areas, the mean difference in the bone‐to‐implant contact was not significant for AE versus TPS (P = 0.010); all other comparisons were not significant. There were 18 membrane exposures in the 72 implant sites. Data were analyzed again to assess the impact of membrane complications. Using a 1‐way analysis of variance, the bone‐to‐implant contact was compared between the sites with and without membrane complications.Conclusion: In this study, the bone‐to‐implant contact was greatest when an HA‐coated implant was used. J Periodontal 2003;74:658‐668
Minocycline‐Induced Staining of Torus Palatinus and Alveolar Bone
Authors: Ayangco Lilibeth , Sheridan Phillip J. 
Published: February 2005

Background: Minocycline hydrochloride, an analog of tetracycline, is widely used in the treatment of acne. Its use has been associated with discoloration of teeth, bone, and other tissues.Methods: A case is presented involving a patient with minocycline‐induced staining of the torus palatinus and alveolar bone.Results: No treatment was rendered since the patient was not concerned with the appearance of the discoloration. The patient's dermatologist elected to change antibiotics.Conclusions: Patients on long‐term minocycline therapy should be made aware of the possibility of pigmentation of bone and soft tissue that may be reversible with discontinuation of therapy; however, minocycline‐induced staining of the permanent dentition may not be reversible. J Periodontol 2003;74:669‐671.
Untreated Periodontal Disease: A Follow‐Up on 30 Cases
Authors: Harris Randall J. 
Published: February 2005

Background: Many studies have shown that periodontal disease can be successfully treated. However, there is limited documentation as to what happens when periodontal disease is left untreated. This study examined patients in a private practice who were diagnosed with periodontal disease and did not complete any treatment. The goal was to see what happened to this group of untreated patients.Methods: Thirty patients with periodontal disease were included in this study. After a mean period of 2.1 years without periodontal treatment, the patients were re‐examined and the changes which occurred evaluated.Results: There was a statistically significant increase in probing depth (3.43 mm to 3.95 mm) and attachment loss (4.19 mm to 4.77 mm) and a statistically significant decrease in the number of teeth present (23.37 to 22.67). Twenty‐one teeth were lost, which was 3.0% of the teeth present at the time of initial diagnosis. The rate of tooth loss was 0.32 teeth/patient/year. The teeth that were lost had deeper recession, probing depths, and attachment loss than the teeth that were retained. Patient factors evaluated could not be associated with statistically significant changes in the clinical parameters, except that smokers had a greater number of sites gaining ≥2 mm of attachment and patients with the poorest oral hygiene had a greater percent of sites breaking down. However, certain site specific variables could be associated with statistically significant changes in the clinical parameters. These included sites: with bleeding on probing, associated with molar furcations, on interproximal surfaces, at posterior teeth, with probing depths ≥3.43 mm, with probing depths ≥7 mm, attachment loss ≥7 mm, and teeth with increased mobility.Conclusions: This group of patients with untreated periodontal disease had greater breakdown and tooth loss than one would expect to see in a group of patients if their periodontal disease was treated. J Periodontol 2003;74:672‐678.
Treatment of Angular Bone Defects with a Composite Bone Grafting Material in Combination with a Collagen Membrane
Authors: Zitzmann Nicola U. , Rateitschak‐Plüss Edith , Marinello Carlo P. 
Published: February 2005

Background: The purpose of this study was to evaluate the effect of a bioabsorbable collagen barrier (CB) in combination with a composite bone substitute (deproteinized bovine bone mineral with collagen, DBBM + C) in periodontal regeneration of angular bone defects in humans using a new application technique.Methods: Twelve patients participated, each contributing at least 1 defect site, which exhibited a probing depth (PD) of ≥5 mm, a clinical attachment level (CAL) of ≥6 mm, and was positive for bleeding on probing (BOP) following initial therapy. Twenty‐two angular bone defects were filled with DBBM + C. A hole was placed in the membrane, which was then pulled over the tooth. The observation period was 2 years and included measurements of plaque, gingivitis, tooth mobility, PD, CAL, soft tissue recession, and bone level as assessed from standardized radiographs.Results: The residual PD and CAL were reduced to 3.3 mm (PD) and 5.6 mm (CAL) with a CAL gain of 3.2 mm at 24 months. The radiographic defect reduction (bone fill) was 4.0 mm after surgery and 2.2 mm at 24 months. The changes measured clinically and radiographically were more pronounced in sites with a deep intrabony defect component than in sites with shallow ones.Conclusions: These findings indicate that angular bone defects can be successfully treated with DBBM + C in combination with CB. A degradation of the filler material seems to occur particularly during the first 6 months, but without affecting the clinical parameters, which improved consistently. J Periodontol 2003;74:687‐694.
Root Coverage in Molar Recession: Report of 50 Consecutive Cases Treated with Subepithelial Connective Tissue Grafts
Authors: Harris Randall J. 
Published: February 2005

Background: The purpose of this study was to evaluate root coverage of molar recession defects.Methods: Fifty patients with a molar recession defect on one molar were treated with a subepithelial connective tissue graft. The procedure was performed as previously reported.Results: Complete root coverage was obtained in 29 of the 50 defects (58%). A mean root coverage of 91.1% was obtained. There was a statistically significant decrease in recession depth (4.4 mm to 0.5 mm), increase in quantity of keratinized tissue (0.9 mm to 3.1 mm), decrease in probing depth (3.0 mm to 2.3 mm), and decrease in attachment level loss (7.4 mm to 2.8 mm).Conclusion: The subepithelial connective tissue graft is an effective method to obtain root coverage of recession defects on molars. J Periodontol 2003;74:703‐708.
Novel Isolation of Alkaline Phosphatase‐Positive Subpopulation from Periodontal Ligament Fibroblasts
Authors: Murakami Yuya , Kojima Takehisa , Nagasawa Toshiyuki , Kobayashi Hiroaki , Ishikawa Isao 
Published: February 2005

Background: Periodontal ligament fibroblasts (PDLFs) are the cells essential for periodontal regeneration. PDLFs comprise a heterogeneous cell population and consist of several cell subsets that differ in their function. It is known that PDLFs produce osteoblast‐related extracellular matrix proteins and show higher alkaline phosphatase (ALP) activity compared with gingival fibroblasts (GFs), implying that PDLFs have osteogenic characterisitics. The aim of the present study was to isolate the osteogenic population of PDLFs according to their expression of ALP.Methods: PDLFs and gingival fibroblasts were separated into two populations, ALP‐positive and ALP‐negative, with an immunomagnetic method using a monoclonal antibody against human bone type ALP and magnetic beads conjugated with a secondary antibody. Expression of basic fibroblast growth factor (bFGF) receptor and transforming growth factor (TGF)‐β receptor was investigated in these two populations. Osteoblastrelated molecules, osteocalcin, and bone sialoprotein; ALP activity; and effect of bFGF on proliferation were also compared.Results: Effective separation was confirmed in both PDLFs and GFs by flow cytometry. The expression of FGF receptor (FGFR) and TGF‐β receptor was significantly higher in ALPpositive PDLFs than in ALP‐negative PDLFs. ALP‐positive PDLFs also expressed higher mRNA levels of osteocalcin and bone sialoprotein compared with ALP‐negative PDLFs. The mitogenic effect of bFGF on ALP‐positive PDLFs was greater than that of ALP‐negative PDLFs.Conclusions: These results indicate that osteoblastic and/or cementoblastic PDLF subsets could be isolated from the PDLF populations using an immunomagnetic method. Magnetic isolation of PDLFs may be a useful tool to obtain the cells which will potentially induce mineralization on the root surface. J Periodontol 2003;74:780‐786.
Effect of Er:YAG and Diode Laser Irradiation on the Root Surface: Morphological and Thermal Analysis
Authors: Theodoro Letícia H. , Haypek Patrícia , Bachmann Luciano , Garcia Valdir G. , Sampaio José E.C. , Zezell Denise M. , Eduardo Carlos de P. 
Published: February 2005

Background: The aim of the present study was to compare the effects of Er:YAG and diode laser treatments of the root surface on intrapulpal temperature after scaling and root planing with hand instruments.Methods: Fifteen extracted single‐rooted teeth were scaled and root planed with hand instruments. The teeth were divided into 3 groups of 5 each and irradiated on their buccal and lingual surfaces: group A: Er:YAG laser, 2.94 μm/100 mJ/10 Hz/ 30 seconds; group B: diode laser, 810 nm/1.0 W/0.05 ms/30 seconds; group C: diode laser, 810 nm/1.4 W/0.05 ms/30 seconds. The temperature was monitored by means of a type T thermocouple (copper‐constantan) positioned in the pulp chamber to assess pulpal temperature during and before irradiation. Afterwards, the specimens were longitudinally sectioned, and the buccal and lingual surfaces of each root were analyzed by scanning electron microscopy.Results: In the Er:YAG laser group, the thermal analysis revealed an average temperature of −2.2 ± 1.5°C, while in the diode laser groups, temperatures were 1.6 ± 0.8°C at 1.0 W and 3.3 ± 1.0°C at 1.4 W. Electronic micrographs revealed that there were no significant morphological changes, such as charring, melting, or fusion, in any group, although the specimens were found to be more irregular in the Er:YAG laser group.Conclusions: The application of Er:YAG and diode lasers at the utilized parameters did not induce high pulpal temperatures. Root surface irregularities were more pronounced after irradiation with an Er:YAG laser than with a diode laser. J Periodontol 2003;74:838‐843.
Platelet‐Rich Plasma Contains High Levels of Platelet‐Derived Growth Factor and Transforming Growth Factor‐β and Modulates the Proliferation of Periodontally Related Cells In Vitro
Authors: Okuda Kazuhiro , Kawase Tomoyuki , Momose Manabu , Murata Masashi , Saito Yoshinori , Suzuki Hironobu , Wolff Larry F. , Yoshie Hiromasa 
Published: February 2005

Background: Platelet‐rich plasma (PRP) is a fraction of plasma, in which platelet‐derived growth factor (PDGF) and transforming growth factor‐β(TGF‐β) are thought to be concentrated. It is plausible that topically‐applied PRP up‐regulates cellular activity and subsequently promotes periodontal regeneration in vivo. However, the concentrations of these growth factors in PRP have not been specifically determined and the biological effects PRP at the cellular and molecular levels have not been determined.Methods: PRP obtained from 20 healthy subjects was prepared from plasma by centrifugation. These PRP preparations were immediately subjected to an evaluation for PDGF‐AB and TGF‐β1 using enzyme‐linked immunosorbent assay (ELISA) kits. The biological effects of the PRP preparations were evaluated on osteoblastic, epithelial, fibroblastic, and periodontal ligament cells. Cellular mitogenic activity was evaluated by counting cell numbers or evaluating 5‐bromodeoxyuridine (BrdU) incorporation. Expression of alkaline phosphatase (ALP) was immunocytochemically evaluated.Results: In the PRP preparations, platelets were concentrated up to 70.9 104 cells/μl (283.4% of the unconcentrated plasma). The levels of PDGFAB and TGF‐β1 were also concentrated up to 182.0 ng/ml (440.6%) and 140.9 ng/ml (346.6%), respectively. Scatter plots revealed significant correlations between platelet counts and levels of these growth factors. PRP stimulated osteoblastic DNA synthesis and cell division (138% of control), with simultaneous down‐regulation of ALP, but suppressed epithelial cell division (80% of control). PRP also stimulated DNA synthesis in gingival fibroblasts and periodontal ligament cells.Conclusions: These data demonstrated that both PDGF‐AB and TGF‐β1 were highly concentrated in the PRP preparations. It is suggested PRP modulates cell proliferation in a cell type‐specific manner similar to what has been observed with TGF‐β1. Since synchronized behavior of related cell types is thought to be required for successful periodontal regeneration, it is further suggested these cell type‐specific actions may be beneficial for periodontal regenerative therapy. J Periodontol 2003;74:849‐857.
Platelet‐Rich Plasma‐Derived Fibrin Clot Formation Stimulates Collagen Synthesis in Periodontal Ligament and Osteoblastic Cells In Vitro
Authors: Kawase Tomoyuki , Okuda Kazuhiro , Wolff Larry F. , Yoshie Hiromasa 
Published: February 2005

Background: Platelet‐rich plasma (PRP) contains several growth factors, including platelet‐derived growth factor (PDGF) and transforming growth factor‐β (TGF‐β), at high levels. We have demonstrated the PRP functions like TGF‐β to modulate cell proliferation in a cell‐type specific manner. In addition, PRP forms gel‐like materials in several, but not all, cell cultures tested. This study was designed to investigate PRP's action on extracellular matrix production in periodontal ligament (PDL) and osteoblastic MG63 cell cultures.Methods: PRP was prepared from the plasma obtained from autologous blood of healthy volunteers and stored at −20°C until used. Cells treated with PRP (0.5% to 2%) were immunocytochemically stained for type I collagen and fibrin and the viscosity of the culture media was visually evaluated. Fibrinogen in PRP was detected by immunodot‐blotting while endogenous thrombin expression in cells was detected by a modified enzymelinked immunosorbent assay.Results: Gel‐like material rapidly (<30 minutes) formed in cultures of either PDL or osteoblastic MG63 cell cultures after addition of PRP (≥0.5%). PRP changed cell shape and up‐regulated type I collagen at 24 hours. Fibrinogen was detected in the PRP preparations and insoluble fibrin networks were found in the newly formed gel‐like material. PRP's action on collagen synthesis was mimicked by purified fibrinogen and blocked by thrombin inhibitor. Thrombin was expressed both in PDL and MG63 cells.Conclusions: These findings demonstrated that the gel‐like material formed in cell cultures of either PDL or MG63 cells is fibrin clot that is capable of up‐regulating collagen synthesis in the extracellular matrix. Our data suggest the possibility that fibrinogen, converted to fibrin, in combination with growth factors present in PRP might effectively promote wound healing at sites of injury in periodontal tissue. J Periodontol 2003;74:858‐864.
Mandibular Fracture Caused by Peri‐Implant Bone Loss: Report of a Case
Authors: Meijer Henny J.A. , Raghoebar Gerry M. , Visser Anita 
Published: February 2005

bold>Background: A major complication related to excessive bone loss around implants is fracture of the mandible. This complication is most likely to occur in a very atrophic mandible. A 57‐year‐old woman presented with progressive pain and swelling that had been present for 5 days in the right frontal region of the mandible. An intraoral radiograph revealed a radiolucency around one of the implants in the interforaminal region.Methods: Ten years earlier, 4 hollow‐screw implants of 10 mm length had been inserted in the interforaminal region of the edentulous mandible. Throughout the 10‐year postoperative period, no adverse clinical events were seen; however, during the last 7 years, no radiographic follow‐up was performed. Mobility was tested after removal of the bar, on which one of the implants appeared to be mobile. The mobile implant was removed together with the fibrous tissue.Results: At a recall visit 2 weeks later, a radiograph revealed a fracture of the mandible at the explantation site. Characteristic features of the hollow‐screw implant are the hollow body and the transverse openings in the side walls of the implant. It has been reported that these characteristic features can enhance infection and rapid bone loss, but a case of mandibular fracture has never been described.Conclusion: Radiographs should be taken on a regular and perhaps more frequent basis to diagnose excessive bone loss, so that measures can be taken to prevent the risk of mandibular fracture. J Periodontol 2003;74:1067‐1070.