Inflammatory response to chlorhexidine, minocycline HCl and doxycycline HCl in an in vivo mouse model.

Aim: To examine the effect of locally delivered antimicrobial drugs on the inflammatory response in an in vivo mouse chamber model.

Material And Methods: Two weeks following chamber implantation, 24 BALB/c mice, in the experimental group, were given an intra-chamber challenge of heat-killed Porphyromonas gingivalis, followed immediately by injection of the specific antimicrobial drug: 2000 microg/ml chlorhexidine (CHX); 1500 microg/ml minocycline HCl;and 1500 microg/ml doxycycline HCl (concentrations achieved in the periodontal pocket with commercial controlled-release delivery systems). A second group of 24 animals received only the antimicrobial treatment without P.

IL-10 gene transfer attenuates P. gingivalis-induced inflammation.

IL-10 is an anti-inflammatory cytokine secreted by stimulated Th2 lymphocytes that can down-regulate inflammatory responses to bacterial challenge. We hypothesized that local delivery of IL-10 using gene-transfer will down-regulate inflammatory responses. We examined the effect of IL-10 plasmid injection on the local cytokine response.

Periodontal destruction is associated with coronary artery disease and periodontal infection with acute coronary syndrome.

Background: Coronary artery disease (CAD) is a highly prevalent disease with significant morbidity and mortality. Periodontal disease has been suggested to influence this disease and has been associated with CAD in some epidemiologic studies. However, this relation is still controversial.

The effect of immunization on the response to P. gingivalis infection in mice is adjuvant-dependent.

Aim: Studies on vaccines against the periodontal pathogen Porphyromonas gingivalis have produced conflicting results, but no consideration has been given to the role of different adjuvants in these vaccines. We have previously shown that an intra-chamber challenge with heat-killed P. gingivalis was modified by immunization with different adjuvants.

Probing depth changes following 2 years of periodontal maintenance therapy including adjunctive controlled release of chlorhexidine.

Background: Multicenter clinical trials have established that the adjunctive use of the subgingival controlled release of chlorhexidine, (CHX chip), significantly reduces probing depth (PD), improves clinical attachment levels, and reduces bleeding on probing compared to scaling and root planing (SRP) alone for periods of up to 9 months. The present report is based on a phase IV clinical trial to examine the adjunctive use of the CHX chip for routine periodontal maintenance therapy (RPMT) over 2 years.

Methods: Eight hundred thirty-five (835) patients were recruited into the study.

Interferon-gamma deficiency attenuates local P. gingivalis-induced inflammation.

Infection with the periodontal pathogen Porphyromonas gingivalis causes a strong local inflammatory reaction. Using IFNgamma-deficient mice, we tested the hypothesis that the absence of IFNgamma would result in a reduction of the local pro-inflammatory response to P. gingivalis.

The effect of titanium surface roughness on the adhesion of monocytes and their secretion of TNF-alpha and PGE2.

Dental implant surfaces are important in determining the tissue/surface interaction. One of the first cells to adhere to the implant surface is the monocyte. This study examines the effect of surface roughness on monocyte adhesion and cytokine secretion.

The relationship between periodontal diseases and diabetes: an overview.

Diabetes mellitus, caused by the malfunction of insulin-dependent glucose and lipid metabolism, presents with the classical triad of symptoms: polydypsia, polyuria, and polyphagia which are often accompanied by chronic fatigue and loss of weight. Complications of diabetes mellitus include retinopathy, nephropathy, neuropathy, and cardiovascular disease. Periodontal diseases are infections affecting the periodontium and resulting in the loss of tooth support.

Histomorphologic changes in the gingiva and pulp of overretained primary teeth.

This study examined the influence of overretention on the tissues of human primary teeth. The range of overretention was two to thirty-two years. Light microscopy and computerized morphometry were utilized for histologic assessment of twenty-five sites of twenty-one teeth.

Repeat bacterial challenge in a subcutaneous chamber model results in augmented tumour necrosis factor-alpha and interferon-gamma response, and suppression of interleukin-10.

The present study compared the effect of a single or a repeat challenge with the Gram-negative pathogen Porphyromonas gingivalis on the local inflammatory response within subcutaneous chamber model in mice. Subcutaneous chambers were implanted 2 weeks prior to the final challenge. The repeat-challenge (REP) group received two intrachamber bacterial injections 14 days apart, while the single-injection group (SIN) received only a single bacterial challenge.

Haim-Munk syndrome and Papillon-Lefèvre syndrome are allelic mutations in cathepsin C.

Of the many palmoplantar keratoderma (PPK) conditions, only Papillon-Lefèvre syndrome (PLS) and Haim-Munk syndrome (HMS) are associated with premature periodontal destruction. Although both PLS and HMS share the cardinal features of PPK and severe periodontitis, a number of additional findings are reported in HMS including arachnodactyly, acro-osteolysis, atrophic changes of the nails, and a radiographic deformity of the fingers. While PLS cases have been identified throughout the world, HMS has only been described among descendants of a religious isolate originally from Cochin, India.

Effects of tetracyclines on the pathologic activity of endotoxin: in vitro and in vivo studies.

Lipopolysaccharide (LPS) is considered to be one of the major virulence factors of Gram-negative bacteria. Recently, tetracyclines (TTCs) were found to prevent the patho-physiological changes associated with LPS in vivo and the secretion of inflammatory mediators in vitro. However, the mechanism by which TTCs prevents LPS-induced pathology in vivo is still unclear.

An in vivo study of the chlorhexidine release profile of the PerioChip in the gingival crevicular fluid, plasma and urine.

The release profile of chlorhexidine from the PerioChip (Chip), a biodegradable local delivery system that contains 2.5 mg of chlorhexidine gluconate (CHX) in a cross-linked hydrolyzed gelatin matrix, into the gingival crevice, was evaluated in an in vivo, open label, single-center, 10-day pharmacokinetic study conducted on 19 volunteers with chronic adult periodontitis. Each volunteer had a single chip inserted into each of 4 selected pockets, with probing pocket depths of between 5-8 mm, at time 0.

The description of a unique population with a very high prevalence of localized juvenile periodontitis.

The reported prevalence of localized juvenile periodontitis (LJP) amongst teenagers and young adults varies greatly. The etiology of LJP has been related to Actinobacillus actinomycetemcomitans (Aa), and it has also been suggested that there may be a transmission of Aa within families resulting in the familial distribution of the disease. This study describes the high prevalence of LJP in adolescents, 12-20 years of age, from a group of nuclear families living and functioning in a closed, closely knit community.

Epidemiological and clinical aspects of periodontal diseases in diabetics.

The association between diabetes mellitus and periodontal disease has long been discussed, with conflicting conclusions. On the one hand, numerous reports indicate a high prevalence of periodontal disease in diabetics compared to healthy controls, while others fail to show such a relationship. Clarification of this dilemma has been occurring as the diagnostic criteria for periodontal disease destruction improve and the number and size of the populations surveyed grow.

Delayed immediate implants: alveolar bone changes during the healing period.

Delaying the placement of immediate fixtures by 6-8 weeks after extraction of the natural dentition allows for the elimination of associated infective processes, the achievement of maximum osteoblastic activity that theoretically could help the osseointegration process and complete wound covering that simplifies the placement of grafts or membranes. This study examines the healing associated with 21 fixtures in 14 patients. The fixtures were placed into sockets 6-8 weeks after tooth extraction without the use of barrier membranes or bone substitutes.

The effects of 17 beta-estradiol on chondrocyte differentiation are modulated by vitamin D3 metabolites.

Both 17 beta-estradiol (17 beta) and the vitamin D metabolites, 1,25-(OH)2D3(1,25) and 24,25-(OH)2D3(24,25), regulate endochondral bone formation in vivo and in vitro. The effects of 17 beta are sex-specific and cell maturation-dependent. Similarly, the effects of 1,25 and 24,25 are cell maturation-dependent, with 1,25 affecting growth zone chondrocytes (GC) and 24,25 affecting resting zone chondrocytes (RC).

Bacterial lipopolysaccharide induces early and late activation of protein kinase C in inflammatory macrophages by selective activation of PKC-epsilon.

Experiments from our and other laboratories have shown that specific inhibitors of protein kinase C (PKC) inhibited the secretion of nitric oxide, TNF alpha, and IL-1 beta from lipopolysaccharide (LPS)-stimulated macrophages, suggesting an important role for PKC in the inflammatory response. The present study was designed to investigate the mechanism whereby LPS stimulates PKC activity in inflammatory macrophages. Mouse macrophages were stimulated with 0-1 microgram/ml LPS for 0-18 hours, and PKC activity was detected in cell lysates.

Subgingival delivery of therapeutic agents in the treatment of periodontal diseases.

This article reviews the current status of controlled local delivery of antibacterial agents in the treatment of periodontitis. The principle of local intrapocket delivery of antibacterial agents and their delivery are discussed. The dosage forms include fibers, film/slabs, and injectable systems, some of which are degradable, while others are not and need to be removed at the termination of the treatment.

Tetracycline inhibits Porphyromonas gingivalis lipopolysaccharide-induced lesions in vivo and TNF alpha processing in vitro.

Lipopolysaccharides (LPS) are considered one of the more important virulence factors related to the pathogenesis of periodontal diseases. Based on tetracycline (TTC) ability to bind divalent metal ions, the present study was designed to examine the effect of TTC on P. gingivalis LPS-induced lesions in vivo and on LPS-induced TNF alpha production in vitro.

Genetic studies of syndromes with severe periodontitis and palmoplantar hyperkeratosis.

The Papillon-Lefèvre and Haim Munk syndromes are characterized by the presence of both palmoplantar hyperkeratosis (PPK) and severe early onset periodontitis. It is the early onset periodontal disease component that distinguishes these from other more common forms of PPK. It has been proposed that the periodontal disease component may be a casual association in individuals with PPK.

Sustained local delivery of chlorhexidine in the treatment of periodontitis: a multi-center study.

The safety and efficacy of a degradable, subgingivally placed drug delivery system containing 2.5 mg chlorhexidine (CHX) were evaluated in a randomized, blinded, multi-center study of 118 patients with moderate periodontitis. A split-mouth design was used to compare the treatment outcomes of scaling and root planing (SRP) alone with the combined use of SRP and the CHX in pockets with probing depths of 5 to 8 mm.

Partial expression of the Papillon-Lefèvre syndrome in 2 unrelated families.

The Papillon-Lefèvre syndrome (PLS) is a rare, autosomal recessive trait that is characterized by palmar plantar keratosis (PPK) and severe, early onset periodontitis, affecting both deciduous and permanent dentitions. The clinical presentation of PLS is variable; the disease occurs so infrequently as to limit clinical cases for study. The exception is a few families with extensive consanguinity in which numerous cases occur.