Showing papers in "Journal of Periodontology in 2003"

The Contribution of Interleukin-1 and Tumor Necrosis Factor to Periodontal Tissue Destruction

Abstract: Interleukin (IL)-1 and tumor necrosis factor (TNF) represent proinflammatory cytokines that stimulate a number of events which occur during periodontal disease. These include the induction of adhesion molecules and other mediators that facilitate and amplify the inflammatory response, the stimulation of matrix metalloproteinase, and bone resorption. The activity of these cytokines coincides with the critical events that occur during periodontal disease, namely, loss of attachment and bone resorption. The use of antagonists to IL-1 and TNF in experimental periodontitis have demonstrated a cause-and-effect relationship between the activity of these cytokines and the spread of an inflammatory front to deeper areas in the connective tissue, loss of connective tissue attachment, osteoclast formation, and loss of alveolar bone. In addition, the loss of fibroblasts that occurs during infection with periodontal pathogens is, in part, mediated by TNF. Thus, much of the damage that occurs during periodontal tissue ...

Ridge Preservation with Freeze-Dried Bone Allograft and a Collagen Membrane Compared to Extraction Alone for Implant Site Development: A Clinical and Histologic Study in Humans

Abstract: Background: Tooth extraction typically leads to loss of ridge width and height. The primary aim of this 6-month randomized, controlled, blinded, clinical study was to determine whether ridge preservation would prevent post-extraction resorptive changes as assessed by clinical and histologic parameters. Methods: Twenty-four patients, 10 males and 14 females, aged 28 to 76 (mean 51.5 ± 13.6), requiring a non-molar extraction and delayed implant placement were randomly selected to receive either extraction alone (EXT) or ridge preservation (RP) using tetracycline hydrated freeze-dried bone allograft (FDBA) and a collagen membrane. A replaced flap, which did not completely cover the sockets, was used. Following extraction, horizontal and vertical ridge dimensions were determined using a modified digital caliper and an acrylic stent, respectively. Prior to implant placement, a 2.7 × 6.0 mm trephine core was obtained and preserved in formalin for histologic analysis. Results: The width of the RP group decreased...

Dimensions of peri-implant mucosa: an evaluation of maxillary anterior single implants in humans.

Abstract: Background: Attempts have been made to evaluate the biologic dimension of osseointegrated implants; however, most are histologic studies in animals, and the effect of soft tissue support from adjacent teeth on the interproximal dimension of the peri-implant mucosa for anterior single implants has not been addressed. This study clinically evaluated the dimensions of the periimplant mucosa around 2-stage maxillary anterior single implants in humans after 1 year of function. The influence of the peri-implant biotype was also examined Methods: Forty-five patients (20 males and 25 females) with a mean age of 47.3 years were included in this study. A total of 45 maxillary anterior single implant crowns with a mean functional time of 32.5 months (range, 12 to 78) were evaluated. The dimensions of peri-implant mucosa were measured by bone sounding using a periodontal probe at the mesial (MI), mid-facial (F), and distal (DI) aspects of the implant restoration and the proximal aspects (MT, DT) of adjacent natural t...

Obesity and periodontal disease in young, middle-aged, and older adults.

Abstract: Background: The growing prevalence of increased body weight and obesity in the United States has raised significant public health concerns. Obesity has been implicated as a risk factor for several chronic health conditions, as well as being associated with increased mortality. Recently, an association between obesity and periodontal disease was found in a Japanese population. The purpose of the present study is to examine the relation between body weight and periodontal disease in a representative United States sample. Methods: Participants in the third National Health and Nutrition Examination Survey (NHANES III) who were ≥18 years and had undergone a periodontal examination were selected for the analysis (n = 13,665). Body mass index (BMI) and waist circumference (WC) were used as measures of overall and abdominal fat content, respectively. Univariable and multivariable logistic regression models were used to estimate the association between increased body weight and periodontal disease. BMI and WC were...

Vertical distance from the crest of bone to the height of the interproximal papilla between adjacent implants.

Abstract: Background: As patient demand increases for more natural restorations in the esthetic zone, clinicians must have the highest level of skill and knowledge to maintain or reform the interdental papilla between teeth, between implants and teeth, and between adjacent implants To date, there are no reports that have measured the distance from the contact point to the bony crest between implants One reason for this may be the fact that, with two adjacent implants, the contact point of the crown can be established at any distance from the gingival margin according to the restorative dentist's specifications Therefore, in this study, the height of the soft tissue to the crest of bone was measured between two adjacent implants independent of the location of the contact point The purpose of this study was to determine the range and average height of tissue between two adjacent implants Methods: A total of 136 interimplant papillary heights were examined in 33 patients by eight different examiners in five private dental offices After administration of appropriate local anesthesia, a standardized periodontal probe was placed vertically from the height of the papilla to the crest of bone The measurements were rounded off to the nearest millimeter Results: The mean height of papillary tissue between two adjacent implants was 34 mm, with a range of 1 mm to 7 mm Conclusions: Clinicians should proceed with great caution when placing two implants adjacent to each other in the esthetic zone In most cases, only 2, 3, or 4 mm of soft tissue height (average 34 mm) can be expected to form over the interimplant crest of bone These results showed that modification of treatment plans may be necessary when esthetics are critical for success

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

Abstract: 849 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 of 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 × 10 4 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.

Periodontal disease and preterm birth: results of a pilot intervention study.

Abstract: Background: Previous case-control and prospective studies have shown an association between the presence of periodontitis and the risk of preterm birth (PTB). The goal of this pilot trial was to determine the feasibility of conducting a trial to determine whether treatment of periodontitis reduces the risk of spontaneous preterm birth (SPTB). Methods: Three hundred sixty-six (366) women with periodontitis between 21 and 25 weeks' gestation were recruited and randomized to one of three treatment groups with stratifi- cation on the following two factors: 1) previous SPTB at <35 weeks and 2) body mass index <19.8 or bacterial vaginosis as assessed by gram stain. The treatment groups consisted of: 1) dental prophylaxis plus placebo capsule; 2) scaling and root planing (SRP) plus placebo capsule; and 3) SRP plus metronidazole capsule (250 mg t.i.d. for one week). An additional group of 723 pregnant women meeting the same criteria for periodontitis and enrolled in a prospective study served as an untreated refe...

Periodontal regeneration in humans using recombinant human platelet-derived growth factor-BB (rhPDGF-BB) and allogenic bone.

Abstract: Background: Purified recombinant human platelet-derived growth factor BB (rhPDGF-BB) is a potent wound healing growth factor and stimulator of the proliferation and recruitment of both periodontal ligament (PDL) and bone cells. The hypothesis tested in this study was that application of rhPDGF-BB incorporated in bone allograft would induce regeneration of a complete new attachment apparatus, including bone, periodontal ligament, and cementum in human interproximal intrabony defects and molar Class II furcation lesions. Methods: Nine adult patients (15 sites) with advanced periodontitis exhibiting at least one tooth requiring extraction due to an extensive interproximal intrabony and/or molar Class II furcation defect were entered into the study. Eleven defects were randomly selected to receive rhPDGF-BB. Following full-thickness flap reflection and initial debridement, the tooth roots were notched at the apical extent of the calculus, the osseous defects were thoroughly debrided, and the tooth root(s) wer...

Five-year clinical, microbiological, and radiological outcome following treatment of peri-implantitis in man.

Abstract: Background: The aim of this study was to evaluate the longterm outcome of a combined surgical and antimicrobial treatment of peri-implantitis lesions in humans. Methods: Nine partially dentate individuals with titanium implants demonstrating a marginal bone loss of ≥ three threads as compared to baseline measurements made from 1-year intraoral radiographs, bleeding on probing, and/or suppuration from the peri-implant sulci were included in the study. In each individual, subgingival bacterial samples were obtained and subjected to microbiological analysis by culture. Surgical exposure of the lesions and cleaning of the implants using hydrogen peroxide were performed. The patients were given systemic antibiotics according to a susceptibility test of target bacteria. The treatment was evaluated clinically, microbiologically, and radiograpically at 6 months, 1 year, and 5 years. Results: Seven out of 26 implants with peri-implantitis at baseline were lost during the 5-year follow-up period despite a significa...

The Role of Gingipains in the Pathogenesis of Periodontal Disease

Abstract: Gingipains are trypsin-like cysteine proteinases produced by Porphyromonas gingivalis, a major causative bacterium of adult periodontitis. HRgpA (95 kDa) and RgpB (50 kDa), products of 2 distinct but related genes, rgpA and rgpB, respectively, are specific for Arg-Xaa peptide bonds. Kgp, a product of the kgp gene, is specific for Lys-Xaa bonds. HRgpA and Kgp are non-covalent complexes containing separate catalytic and adhesion/ hemagglutinin domains, while RgpB has only a catalytic domain with a primary structure essentially identical to that of the catalytic subunit of HRgp. HRgpA and RgpB induce vascular permeability enhancement through activation of the kallikrein/kinin pathway and activate the blood coagulation system, which, respectively, are potentially associated with gingival crevicular fluid production and progression of inflammation leading to alveolar bone loss in the periodontitis site. Kgp is the most potent fibrinogen/fibrin degrading enzyme of the 3 gingipains in human plasma and is involved in the bleeding tendency at the diseased gingiva. HRgpA activates coagulation factors and degrades fibrinogen/fibrin more efficiently than RgpB due to the adhesion/hemagglutinin domains, which have affinity for phospholipids and fibrinogen. Gingipains degrade macrophage CD14, thus inhibiting activation of the leukocytes through the lipopolysaccharide (LPS) receptor, and thereby facilitating sustained colonization of P. gingivalis. Gingipains play a role in bacterial housekeeping and infection, including amino acid uptake from host proteins and fimbriae maturation. Based on the important activities of gingipains in the bacterial infection and the pathogenesis of periodontitis, the bacterial proteinases can be targets for periodontal disease therapy. Immunization with RgpB, HRgpA, or a portion of HRgpA catalytic domain attenuated P. gingivalis induced disorders in mice. In addition, a trypsin-like proteinase inhibitor retarded P. gingivalis growth specifically. Gingipains are potent virulence factors of P. gingivalis, and are likely to be associated with the development of periodontitis. It is, therefore, suggested that gingipain inhibition by vaccination and gingipain-specific inhibitors is a useful therapy for adult periodontitis caused by P. gingivalis infection.

Effect of non-surgical Periodontal therapy on glycemic control in patients with type 2 diabetes mellitus

Abstract: Background: The literature suggests that an alteration in glucose metabolism occurs as a result of antibacterial periodontal therapy. The objective of this study was to monitor the effect of non-surgical periodontal therapy on glycemic control in patients with type 2 diabetes mellitus (DM). Methods: Thirty type 2 DM subjects with periodontitis were randomly divided into two groups. Group 1 (G1), 15 subjects, received one-stage full-mouth scaling and root planing (FMSRP) plus amoxicillin/clavulanic acid 875 mg; group 2 (G2), 15 patients, received only FMSRP. At baseline and after 3 months, the glycated hemoglobin (HbA1c) values, fasting glucose, and clinical parameters (with computerized probing and individualized acrylic stents) were recorded. Following therapy, the subjects were enrolled in a 2-week interval maintenance program for 3 months. Results: After treatment, both groups showed clinical improvements. A probing depth (PD) reduction of 0.8 ± 0.6 mm (P <0.05) occurred in G1 and 0.9 ± 0.4 mm in G2 (P...

Neutrophil-Mediated Tissue Injury in Periodontal Disease Pathogenesis: Findings from Localized Aggressive Periodontitis

Abstract: Neutrophils play a major role in the host response against invading periodontopathogenic microorganisms. Localized aggressive periodontitis (LAgP) is associated with various functional abnormalities of neutrophils. Based on the recent findings, LAgP neutrophils are not "hypofunctional" or "deficient." They are "hyperfunctional," and their amplified activity is responsible for the tissue destruction in periodontal disease. Several signal transduction abnormalities are associated with elevated neutrophil function in LAgP. There is a strong correlation between defective chemotaxis and decreased intracellular Ca2+ levels; total calcium-dependent protein Kinase C (PKC) activity of neutrophils is significantly lower than healthy subjects; and there is a marked increase in diacylglycerol (DAG) accompanied by a pronounced decrease in DAG kinase activity. In a separate set of experiments on the involvement of the inducible cyclooxygenase isoform (COX-2) and the role of novel lipid mediators in the pathogenesis of periodontal disease, crevicular fluid samples from LAgP patients were found to contain prostaglandin E2 (PGE2) and 5-LO-derived products, leukotriene B4 (LTB4), and the biosynthesis interaction product, lipoxin LXA4. Neutrophils from peripheral blood of LAgP patients, but not from healthy volunteers, also generated LXA4, suggesting that this immunomodulatory molecule may have a role in periodontal disease. Lipoxin generation and its relationship to PGE2 and LTB4 can be visualized as an important marker for the pathogenesis of periodontal disease. Thus, major advances in our understanding of the role of the neutrophil in host defense against periodontal organisms have been made through studies of LAgP. LAgP is used as an example of a severe periodontal disease that is related to abnormal neutrophil function. In this model, it appears that a hyperresponsiveness of the neutrophil, due to cell priming/predisposition, results in enhanced tissue damage.

Periodontal disease and diabetes mellitus: The role of tumor necrosis factor-α in a 2-way relationship

Abstract: It is generally accepted that obesity is associated with many other multiple-risk factor syndromes such as hypertension, hyperlipidemia, type 2 diabetes mellitus, and periodontal disease. The number of obese people is increasing rapidly in both western and eastern countries. Adipocytes in the adipose tissues of obese people produce large quantities of biologically active molecules such as leptin, an important molecule regulating energy expenditure and body weight. Therefore, adipocyte-derived active molecules, named adipocytokines, are candidate molecules accounting for the close association between obesity and other multiple-risk factor syndromes. The proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) is produced by adipocytes, and its blood concentration is elevated in obese patients and declines with weight loss. Studies have demonstrated that TNF-alpha suppresses insulin action via its specific receptor; hence, it exacerbates insulin resistance. In addition to adipocytes, monocytes/macrophages produce large quantities of TNF-alpha. Thus, TNF-alpha, produced from monocytic cells due to inflammatory diseases, may have an additive influence on insulin sensitivity to adipocyte-derived TNF-alpha. Here, we hypothesized that 1) TNF-alpha produced by the adipose tissues of obese patients acts as a risk factor for periodontal inflammation, and 2) TNF-alpha produced due to periodontal inflammation may be an additional important factor influencing insulin sensitivity in both obese and type 2 diabetic patients. We believe that this interaction is a possible mechanism accounting for a 2-way relationship between type 2 diabetes and periodontal disease.

Diagnosis of periodontal diseases.

Abstract: At the present time, the diagnosis and classification of periodontal diseases are almost entirely based on traditional clinical assessments. Supplemental quantitative and qualitative assessments of the gingival crevicular fluid and subgingival microflora can potentially provide useful information about the patient's periodontal disease. In certain situations, these supplemental risk-assessment tests may be particularly valuable in establishing the endpoint of therapy prior to placing patients on a periodontal maintenance program. Although the clinical utility of none of these tests has been validated, their further development is warranted. A genetic test for susceptibility to periodontitis has become commercially available. How best to use this and future host-based tests in clinical practice remains to be determined. Probing depth and clinical attachment loss measurements obtained with periodontal probes are practical and valid methods for assessing periodontal status. Computer-linked, controlled-force electronic periodontal probes are commercially available and are currently in use by some practitioners. Many of the logistical problems associated with subtraction radiography are being overcome and this powerful diagnostic tool may soon come into widespread use. Future developments in this and other imaging techniques are likely to have a profound effect on our approach to the diagnosis of periodontal diseases.

Effect of ER:YAG and diode laser irradiation on the root surface: morphological and thermal analysis.

Abstract: 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 di...

Immediate Functional and Non-Functional Loading of Dental Implants: A 2- to 60-Month Follow-Up Study of 646 Titanium Implants

Abstract: Background: The aim of this study was the evaluation, from a clinical point of view, of implants subjected to immediate functional loading (IFL) and to immediate non-functional loading (INFL) in various anatomical configurations. Methods: The study included 152 patients who had given their informed consent. A total of 646 implants were inserted. The implants were placed in 39 totally edentulous mandibles, 14 edentulous maxillae, 23 edentulous posterior mandibles, 16 edentulous anterior mandibles, 16 edentulous anterior maxillae, and 15 edentulous posterior maxillae. Fifty-eight implants were used to replace single missing teeth. In 65 cases, IFL was carried out for 422 implants. INFL was carried out in 116 cases, (224 implants). Results: In the IFL group 6 of 422 implants failed (1.4%); in the INFL group 2 of 224 implants failed (0.9%). All the other implants appeared, from clinical and radiographic observations, to have successfully osseointegrated and have been functioning satisfactorily since insertion...

Relationship of destructive periodontal disease to the acute-phase response.

Abstract: Background: Destructive periodontal diseases have been associated with an increased risk of atherosclerotic complications; however, the potential mechanisms are yet to be defined. Inflammation plays a central role in atherosclerosis since C-reactive protein (CRP), an acute-phase protein monitored as a marker of inflammatory status, has been identified as a major risk factor for atherosclerotic complications. Recent reports that destructive periodontal diseases can increase CRP values present the possibility that the acute-phase response may link these 2 disease processes. The objective of the present investigation was to determine the effect of destructive periodontal disease status, severity, and progression on components of the acutephase response in an urban minority population. Methods: Clinical measurements recorded included probing depth, attachment level, gingival erythema, bleeding upon probing, suppuration, and plaque. Disease progression was defined as a>2 mm loss of attachment 2 months post-baselin...

Platelet-rich plasma-derived fibrin clot formation stimulates collagen synthesis in periodontal ligament and osteoblastic cells in vitro

Abstract: 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 ...

Role of the microgap between implant and abutment: a retrospective histologic evaluation in monkeys.

Abstract: Background: It has been hypothesized that a certain width of the peri-implant mucosa is required to enable a proper epithelialconnective tissue attachment and, if this soft tissue dimension is not adequate, bone resorption will occur to ensure the establishment of attachment with an appropriate biological width. The reason for the accelerated bone loss around submerged 2-piece implants in the first year after the restoration is not known, but one possibility is that the gap between components plays a role in this process. Recent studies have shown that for all 2-part implants, the bone crest level changes appeared dependent on the location of the microgap. Methods: The aim of the present study was a retrospective histologic evaluation in monkeys of the bone response to implants inserted 1 to 2 mm above the alveolar crest (group 1, 15 implants), at the level of the alveolar crest (group 2, 12 implants), or 1 to 1.5 mm below the alveolar crest (group 3, 13 implants). These implants had been early loaded, im...

Molecular interaction of Porphyromonas gingivalis with host cells: implication for the microbial pathogenesis of periodontal disease.

Abstract: Porphyromonas gingivalis is a predominant periodontal pathogen, which expresses a number of potential virulence factors involved in the pathogenesis of periodontitis. Among them, fimbriae are a critical factor to mediate the bacterial interaction with host tissues, which promotes the bacterial adhesion to and invasion of the targeted sites. Fimbriae are capable of binding to human salivary components, commensal bacteria, and a variety of host cells including macrophages, epithelial cells, and fibroblasts. Human extracellular matrix (ECM) proteins such as vitronectin and fibronectin play important roles in cellular signal transduction via binding to receptor integrins. Fimbriae showed significant binding affinity to ECM proteins and clearly inhibited the molecular interactions between vitronectin/fibronectin and their receptor alphavbeta3 and alpha5beta1 integrins overexpressed on Chinese hamster ovary (CHO) cell strain. P. gingivalis fimbriae are likely to interrupt the cellular signaling via ECM proteins/integrins in periodontal regions. Fimbriae are also thought to be critically important in invasive events of the organism to host cells. The fimA genes, encoding FimA (a subunit of fimbriae), of P. gingivalis strains are classified into 5 types, I to V. Recent clinical investigations demonstrated the close relationship between the organisms with type II fimA and periodontitis development. Recombinant FimA (rFimA) proteins of types I to V were generated to compare their adhesion/invasion abilities to human gingival fibroblasts (HGF) and a human epithelial cell line (HEp-2 cells), respectively. There were no significant differences in the adhesion ability of microspheres (MS) coated with these rFimAs to HGF; however, the adhesion of type II rFimA-MS to HEp-2 cells was significantly greater than that of other rFimA types. It was also observed that the type II rFimA-MS markedly invaded the epithelial cells and accumulated around the nuclei. Collectively, these findings suggest that fimbriae of P. gingivalis, especially type II, are involved in the initiation and progression of human periodontitis.

Gene therapy of bone morphogenetic protein for periodontal tissue engineering.

Abstract: Background: The reconstruction of lost periodontal support including bone, ligament, and cementum is a major goal of therapy. Bone morphogenetic proteins (BMPs) have shown much potential in the regeneration of the periodontium. Limitations of BMP administration to periodontal lesions include need for highdose bolus delivery, BMP transient biological activity, and low bioavailability of factors at the wound site. Gene transfer offers promise as an alternative treatment strategy to deliver BMPs to periodontal tissues. Methods: This study utilized ex vivo BMP-7 gene transfer to stimulate tissue engineering of alveolar bone wounds. Syngeneic dermal fibroblasts (SDFs) were transduced ex vivo with adenoviruses encoding either green fluorescent protein (Ad-GFP or control virus), BMP-7 (Ad-BMP-7), or an antagonist of BMP bioactivity, noggin (Ad-noggin). Transduced cells were seeded onto gelatin carriers and then transplanted to large mandibular alveolar bone defects in a rat wound repair model. Results: Ad-noggin...

Expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in healthy and diseased human gingiva.

Abstract: Background: The purpose of this study was to quantify the amount of matrix metalloproteinases such as MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, and MMP-13 and tissue inhibitors of metalloproteinases TIMP-1 and TIMP-2 expressed by human gingival explants in culture media and the area fraction (AA%) of gingival collagen fibers according to the degree of inflammation, to investigate a possible correlation between these enzymes and collagen loss. Methods: Gingival tissue specimens from 6 healthy controls (group 1), 17 patients with mild gingival inflammation (group 2), 10 patients with moderate gingival inflammation (group 3), and 9 patients with severe gingival inflammation (group 4) were placed in organ culture for 3 days. The MMPs and TIMPs in the culture media were quantified using zymography, dot blotting, and Western blotting. Paraffin gingival sections were stained with sirius red F3Ba for visualization of collagen fibers, then the area fraction (AA%) occupied by the gingival fibers was determined by automate...

Bucco-lingual bone remodeling around implants placed into immediate extraction sockets: a case series.

Abstract: Background: Implants placed immediately after tooth extraction have shown high percentages of clinical success. Few studies in the scientific literature have observed the horizontal bone remodeling in the buccallingual direction after immediate placement of implants. The aim of this study was to analyze bone healing and coronal bone remodeling around 15 implants placed immediately after tooth removal without the use of guided bone regeneration (GBR) techniques. Methods: Ten patients received a total of 15 implants placed immediately after removal of 15 single-rooted teeth. All implants were placed within the alveolar confines, limiting, in most cases, small periimplant bone defects. After implant placement, the distance from the buccal to lingual bone plate was measured. No membranes or filling materials were used. Primary flap closure was performed in all cases. Results: At second-stage surgery, all peri-implant defects were completely filled and the distance from buccal to lingual bone was measured agai...

Evaluation of human recession defects treated with coronally advanced flaps and either enamel matrix derivative or connective tissue. Part 1: Comparison of clinical parameters.

Abstract: Background: Recession defects around teeth have been treated with a variety of surgical techniques. Most of the literature suggests that the subepithelial connective tissue graft has the highest percentage of mean root coverage with the least variability. Previous studies have demonstrated that enamel matrix derivative (EMD) has the ability to improve clinical parameters. The purpose of this study was to compare the clinical efficacy of enamel matrix derivative placed under a coronally advanced flap to subepithelial connective tissue placed under a coronally advanced flap in patients with recession type defects. Methods: Twenty patients with incisors or premolars presenting with a facial recession of ≥4 mm in contralateral quadrants of the same jaw were treated; 17 patients completed the study. One tooth in each patient was randomized to receive either a coronally advanced flap with a subepithelial connective tissue graft (control) or a coronally advanced flap with EMD (test). Clinical parameters measured...

Antimicrobial periodontal treatment decreases serum C-reactive protein, tumor necrosis factor-alpha, but not adiponectin levels in patients with chronic periodontitis

Abstract: Background: Elevated levels of C-reactive protein (CRP) and decreased plasma adiponectin are associated with increased risk of atherosclerosis. Furthermore, recent observations suggested that adiponectin and tumor necrosis factor-α(TNF-α) suppressed each other’s production. Since periodontal disease has been suggested to act as a risk factor for atherosclerosis, we examined the effects of antimicrobial periodontal treatment on CRP, adiponectin, and TNF-α levels. Methods: Fifteen chronic periodontitis patients with various systemic conditions at high risk for atherosclerosis were enrolled in the study. Patients were non-surgically treated with topical application of antibiotics and mechanical debridement of calculus once a week for 1 month. Before and after therapy, CRP, adiponectin, and TNF-α levels were measured. Results: Both CRP and TNF-α levels were signifi- cantly decreased after treatment (P <0.01 and P <0.03, respectively), while adiponectin levels did not change significantly. Conclusions: Periodo...

Surgical crown lengthening: evaluation of the biological width.

Abstract: Background: Previous surgical crown lengthening studies have investigated positional changes of the free gingival margin but not the biological width. Histological studies utilizing animal models have shown that postoperative crestal resorption allowed reestablishment of the biological width. However, very little work has been done in humans. Therefore, the purpose of this study was to evaluate the positional changes of the periodontal tissues, particularly the biological width, following surgical crown lengthening in human subjects. Methods: Twenty-three (23) patients who needed surgical crown lengthening to gain retention necessary for prosthetic treatment and/or to access caries, tooth fracture, or previous prosthetic margins entered the study. The following parameters were obtained from line angles of treated teeth (teeth requiring surgical crown lengthening) and adjacent teeth with adjacent and non-adjacent sites: plaque and gingival indexes, free gingival margin, probing depth, attachment level, bon...

Treatment of ligature-induced peri-implantitis by lethal photosensitization and guided bone regeneration: A preliminary histologic study in dogs

Abstract: Background: The purpose of this pilot study was to evaluate the healing potential and reosseointegration in ligature-induced peri-implantitis defects adjacent to various dental implant surfaces following lethal photosensitization. Methods: A total of 36 dental implants with 4 different surface coatings (9 commercially pure titanium surface [CPTi]; 9 titanium plasma-sprayed [TPS]; 9 hydroxyapatite [HA]; and 9 acid-etched [AE]) were inserted in 6 male mongrel dogs 3 months after extraction of mandibular premolars. After a 2-month period of ligature-induced peri-implantitis and 12 months of natural peri-implantitis progression, only 19 dental implants remained. The dogs underwent surgical debridement of the remaining dental implant sites and lethal photosensitization by combination of toluidine blue O (100 µg/ml) and irradiation with diode laser. All exposed dental implant surfaces and bone craters were meticulously cleaned by mechanical means, submitted to photodynamic therapy, and guided bone regeneration ...

Bone-Implant Contact on Machined and Dual Acid-Etched Surfaces After 2 Months of Healing in the Human Maxilla

Abstract: Background: Recent clinical studies indicate that an implant with a textured surface may be loaded sooner than traditional healing protocols have recommended. In a previous study, the 6-month bone-implant contact for dual acid-etched and machined implant surfaces was reported to be 72.96% and 33.98%, respectively. In 1991, a minimum of 50% bone-implant contact was considered necessary for loading to ensure long-term survival of the implant. This study evaluated the 2-month bone-implant contact for dual acidetched and machined implant surfaces to determine if this criterion had been met. Methods: Custom manufactured implants (2 mm diameter and 5 mm length), having on one side a machined surface and on the other side a dual acid-etched surface, were placed in the posterior maxilla of 11 patients, allowed to integrate for 2 months, then removed using a 4 mm internal diameter trephine with irrigation. Sections were processed and stained for histologic and histomorphometric analysis. The parameters calculated ...

Perspective of cytokine regulation for periodontal treatment: fibroblast biology.

Abstract: Efforts to understand the pathogenesis of periodontal diseases have been underway for decades. Studies of immunological aspects in addition to the structural components of gingival fibroblasts showed that the fibroblasts actively participate in immune and inflammatory events in periodontal diseases. Future strategies for the prevention and treatment of periodontal diseases should biologically regulate fibroblast activities. These cells are surrounded by monocyte-derived proinflammatory cytokines such as interleukin-1 beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), and lymphocyte-derived interleukin-6 (IL-6) in inflamed gingival tissue. Recent anti-cytokine therapy for inflammatory diseases including rheumatoid arthritis aimed to inhibit the binding of cytokines to targeted cells such as fibroblasts and condrocytes. IL-1beta and TNF-alpha are thought to be therapeutic targets because these cytokines are essential for the initiation of inflammatory immune reactions and are produced for prolonged periods in inflammatory diseases. IL-6 is also a target, because it is abundantly present in inflammatory lesions and activates fibroblasts in the presence of soluble IL-6 receptor. In addition, these cytokines accelerate gingival fibroblasts to produce collagenolytic enzymes, resulting in tissue destruction. Soluble receptors for IL-1beta and TNF-alpha are suggested to be candidates for therapeutic molecules, but soluble receptor for IL-6 is suggested to be a factor-stimulating fibroblast. This paper will review the utilization of soluble receptors specific to inflammatory cytokines which potentially stimulate fibroblasts to regulate biological events involved in the pathogenesis of periodontal diseases.

Evidence-based Mucogingival Therapy. Part 2: Ordinary and Individual Patient Data Meta-Analyses of Surgical Treatment of Recession Using Complete Root Coverage as the Outcome Variable

Abstract: Background: The literature (1970-2000) on the outcome of surgical root coverage has been revised and summarized in a companion paper. The overall conclusion was that the various procedures are effective, but it was not possible to determine which procedure was best indicated in different clinical conditions. In this study, meta-analysis techniques were used to seek evidence for guiding clinical decisions when planning root coverage surgery. The aim of this study was to illustrate the differences between meta-analyses applied to summarized and individual patient data (IPD) and to present suggestions for reducing the costs of IPD meta-analysis. Methods: Only clinical trials and case series that included data on the number of teeth treated, baseline recession depth (BRD) and the proportions of postoperative complete root coverage (CRC) were considered. The first group of meta-analyses (the outcome of each procedure based on summarized data) covered 65 studies dealing with coronally advanced flap (CAF), epith...