Smoking and gingivitis: focus on inducible nitric oxide synthase, nitric oxide and basic fibroblast growth factor.

BACKGROUND: Periodontal disease pathogenesis has been associated with smoking. Gingivitis is a mild and reversible form of periodontal disease and it tends to progress to periodontitis only in susceptible individuals. In the present study, we aimed to examine the impact of smoking on host responses in gingivitis and to evaluate and compare the inducible nitric oxide synthase (iNOS) activity in gingival tissue and NO and basic fibroblast growth factor (bFGF) levels in the gingival crevicular fluid of patients with gingivitis and healthy individuals. MATERIAL AND METHODS: Forty-one participants were assigned to the gingivitis-smoker (n = 13), gingivitis (n = 13), healthy-smoker (n = 7) and healthy groups (n = 8). Clinical indices were recorded; gingival biopsy and gingival crevicular fluid samples were obtained from papillary regions. iNOS expression was evaluated by immunohistochemical staining. The immunoreactive cells were semiquantitatively assessed. For the quantitative determination of nitrite and nitrate in gingival crevicular fluid, the NO assay kit was used. The amount of bFGF in gingival crevicular fluid was determined by enzyme-linked immunosorbent assay. RESULTS: The gingivitis-smoker group demonstrated a stronger iNOS expression than the non-smoker gingivitis group. iNOS expression intensity was lower in the non-smoker healthy group compared to that in healthy-smokers. No significant gingival crevicular fluid NO and bFGF level changes were observed between groups. Among patients with gingivitis, a positive correlation was detected between gingival crevicular fluid NO and bFGF levels (r = 0.806, p = 0.001). CONCLUSIONS: Our data suggest that smoking has significant effects on iNOS expression but not on gingival crevicular fluid NO or bFGF levels in healthy and patients with gingivitis. However, our results suggest that bFGF might be involved in the regulation of NO production via iNOS.

Localized alveolar bone necrosis following the use of an arsenical paste: a case report.

AIM: To describe some toxic effects of arsenic trioxide in the mouth, to condemn its continued use, and present a case in which a tooth was preserved despite significant bony destruction. SUMMARY: A case is presented in which severe alveolar bone necrosis resulted from leak-age of an arsenical devitalization paste into the periodontium. The tooth was root canal treated before root amputation, and restored with a cuspal coverage restoration. The tooth was observed to be symptomless and functional at the one-year follow-up. KEY LEARNING POINTS: * Arsenic and its compounds have no place in contemporary endodontics. * Dentists should protect their patients by avoiding the use of arsenic-containing materials and refusing to use products whose constituents are not known. * Localized bone necrosis may not require tooth extraction. Depending on the severity of the case, the tooth may be preserved by a combination of endodontic, periodontal,prosthodontic and maintenance therapies.

Genetic diversity of Porphyromonas gingivalis and its possible importance to pathogenicity.

During recent years much effort has been put into understanding the genetic composition of the oral populations of black-pigmented anaerobic bacteria. One of them, Porphyromonas gingivalis, is a putative periodontopathogenic organism considered to be particularly relevant in the etiology of adult periodontitis. It has been shown in studies using molecular typing methods that most bacterial populations consist of numerous genetic clones, and that only a small proportion of these clones cause disease. Elucidation of a possible association of genotypic profiles with either disease or clinical healthy condition is important for understanding the pathogenic characteristics of bacteria. Studies addressing this issue as it relates to P. gingivalis are reviewed in the present article. Genotypic characterization of P. gingivalis strains has revealed extensive heterogeneity in natural populations of this bacterium. Some of the potential virulence factors of P. gingivalis have been purified and cloned and methods have been established to identify their genes. Although no studies have clearly defined the relationship between a specific genotype of P. gingivalis and periodontal status of the host, it seems that molecular typing tools, which are undergoing rapid improvements, will allow us to distinguish between virulent and avirulent strains of the same species in the near future.

Chitosan film enriched with an antioxidant agent, taurine, in fenestration defects.

A natural polysaccharide, chitosan (poly-N-acetyl glucosaminoglycan), which is a nontoxic and bioabsorbable polymer, has been shown to have hemostatic and antibacterial effects. An amino acid, taurine, is considered to be beneficial for regulating the inflammation process. The purpose of this study was to investigate the synergistic effects of taurine and chitosan in the experimental defects at the vestibular bone of maxillary canine teeth in six dogs. Chitosan films were prepared as delivery system with or without taurine and placed in the randomly chosen defects. Biopsies were performed on the postoperative seventh day and routine histological procedures were performed for light and electron microscopic evaluations. For each group, 30 different microscopic areas were examined and the numbers of macrophages and neutrophils in these areas were counted. The mean numbers of both macrophages and neutrophils were found statistically different between the chitosan film incorporated with taurine and free chitosan groups (p < 0.0001 p > 0.05). In addition to the increase in cell counts in both groups, the cytological alterations were more obvious in the chitosan film group incorporated with taurine. Accordingly, taurine appears to enhance the acceleration effect of chitosan on wound healing at early periods. This effect could be considered beneficial in tissue repair in destructive diseases like periodontitis.

Salivary arginase in patients with adult periodontitis.

Human saliva has been shown to possess enzymatic activities, one of which is derived from arginase. Arginase is known to be an arginine-depleting enzyme belonging to the L-arginine/nitric oxide pathway. The aim of this study was to examine the possible role of arginase activity of saliva in the pathogenesis of periodontal disease. Mixed saliva samples were collected from 20 adult periodontitis patients and 15 systemically and periodontally healthy subjects. Salivary arginase and total protein contents were determined by using spectrophotometrical enzyme analysis and salivary arginase was expressed as specific activity. Periodontal disease status was determined by clinical periodontal assessments including probing pocket depth, clinical attachment level, plaque index and gingival index. While the increase in total protein was not statistically significant, arginase levels in the patient group were significantly higher than the controls. All periodontal indices were found to be significantly higher in the periodontitis group, but no meaningful correlation was observed between the biochemical and periodontal variables in both groups. Furthermore, no significant correlation existed between the amount of arginase and total protein. In conclusion, it was suggested that salivary arginase activity in periodontitis along with the arginine-nitric oxide pathway may be involved in the disease process by using the common substrate L-arginine and inhibiting nitric oxide production.

The effect of a collagen membrane in regenerative therapy of two-wall intrabony defects in dogs.

Guided tissue regeneration that supports the periodontal ligament and bone cells in achieving healthy attachment between teeth and alveolar bone following periodontal therapy has been repeatedly described in the literature. The aim of the present study was to assess the effect of an absorbable collagen membrane used in guided tissue regeneration procedures in two-wall intrabony defects. For this purpose, periodontal defects were surgically created around mandibular teeth in nine dogs. In a randomly chosen quadrant in each dog, a collagen membrane was shaped to cover the interproximal bone defect and adjacent root surface. No collagen membrane was placed over the control defects. Block biopsies of test and control sites were obtained from three dogs at 30 days, three dogs at 60 days, and three dogs at 90 days after the procedures. Histomorphologic and histometric evaluations were performed. We observed that both collagen membrane treated and control defects demonstrated similar amounts of new attachment and bone. However, gingival recession and postoperative keratinized tissue loss were observed in most of the sites. Although there was a tendency towards new attachment in both groups, the gingival tissue loss due to recession led to limited regeneration.

Intrafamilial transmission of black-pigmented, putative periodontal pathogens.

Porphyromonas gingivalis and Prevotella intermedia are black-pigmented, putative periodontopathogenic bacteria considered to cause some forms of periodontal disease. Porphyromonas gingivalis and P. intermedia can be transmitted between humans and produce periodontal disease in susceptible hosts. In this article, studies using molecular typing methods for determining the transmission of black-pigmented, putative periodontopathogens between family members are reviewed. As individuals living close to each other are more prone to transmit bacteria, the studies on transmission of periodontopathogens have been performed on family members. It has been shown that black-pigmented bacteria are not only transferred between spouses but also between parents and child. Since only a limited number of studies have been done, longitudinal and controlled studies should be carried out to elucidate further the transmittance potential of these bacteria.

The correlation of gingival crevicular fluid interleukin-8 levels and periodontal status in localized juvenile periodontitis.

Localized juvenile periodontitis (LJP) is an early-onset periodontal disease characterized by progressive bone loss involving the permanent first molar and incisor teeth. Approximately 70% to 75% of LJP patients have impaired neutrophil chemotaxis towards a number of chemoattractants including N-formyl-methionyl-leucyl-phenyl-alanine, complement fragment C5a, leukotriene B4, and interleukin 8 (IL-8). The aim of the present study was to observe the role of IL-8 in the pathogenesis of LJP. Fourteen individuals who were systemically and periodontally healthy and 24 systemically healthy individuals diagnosed with LJP (based on the results of clinical periodontal assessments and radiographic examination) were recruited for this study. Gingival crevicular fluid (GCF) samples were obtained from anterior teeth in each subject before treatment. After evaluation of GCF amount from paper strips, enzyme-linked immunoabsorbent assay was employed to determine the amount of IL-8 in GCF. The amount and concentration of IL-8 measured was 894.5 +/- 435 pg, and 445.3 +/- 468 pg/microl for the experimental group and 747.3 +/- 543 pg and 684.7 +/- 548 pg/microl, for the control group. The correlation among the levels of cytokine and clinical parameters was assessed. It was observed that the concentration of IL-8 demonstrated a negative correlation with gingival index in the LJP group. In addition, no significant correlation was found among the total amount and concentration of IL-8, GCF volume, and clinical parameters in the control group. IL-8 is thought to enhance host defense mechanisms against gram-negative bacteria, thus providing protection against periodontal infections. Our data demonstrate that, when both the total amount and concentration of IL-8 are taken into consideration, no significant difference between LJP and healthy subjects is shown. This may indicate a less active IL-8 production compared with healthy subjects in spite of the dense Gram bacterial stimulation in LJP.