Detection of periodontal bacteria in atheromatous plaque by nested polymerase chain reaction.

BACKGROUND: In recent years, increasing evidence regarding the potential association between periodontal diseases and cardiovascular diseases has been identified. The available evidence underlines the importance of detecting periodontal pathogens on atheromatous plaque as the first step in demonstrating the causal relationship between the two conditions. The main aim of this investigation is to detect periodontitis-associated bacteria from carotid artery atheromatous plaque from patients who received an endarterectomy using strict sample procurement and laboratory procedures. METHODS: Atheromatous plaque from endarterectomies from carotid arteries were scraped and homogenized, and bacterial DNA was extracted. To obtain a representative concentration of amplicons, two amplifications of the bacterial 16S ribosomal-RNA gene were carried out for each sample with universal eubacteria primers by a polymerase chain reaction (PCR). A nested PCR with specific primers for the target bacteria was performed next. Statistical tests included the χ(2) test. RESULTS: Forty-two atheromatous plaque were analyzed. All of them were positive for ≥1 target bacterial species. The bacterial species most commonly found was Porphyromonas gingivalis (78.57%; 33 of 42), followed by Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) (66.67%; 28 of 42), Tannerella forsythia (previously T. forsythensis) (61.90%; 26 of 42), Eikenella corrodens (54.76%; 23 of 42), Fusobacterium nucleatum (50.00%; 21 of 42), and Campylobacter rectus (9.52%; four of 42). The simultaneous presence of various bacterial species within the same specimen was a common observation. CONCLUSION: Within the limitations of this study, the presence of DNA from periodontitis-associated bacteria in carotid artery atheromatous plaque retrieved by endarterectomy is confirmed.

MMP-13 and TIMP-1 determinations in progressive chronic periodontitis.

UNLABELLED: Matrix metalloproteinase (MMP)-13 is a collagenase involved in extracellular matrix degradation either by its direct degradative effects or by processing bioactive substrates. The aim of this study was to determine the levels of MMP-13 and tissue inhibitor of metalloproteinase (TIMP)-1 in gingival crevicular fluid (GCF) and gingival biopsies obtained from active and inactive sites during chronic periodontitis progression. MATERIALS AND METHODS: This was a longitudinal study in which chronic periodontitis patients with moderate to severe disease were included and followed until they developed progression determined by the tolerance method. GCF samples were obtained from periodontitis, active, inactive and healthy sites and additional gingival biopsies were taken from active and inactive sites. MMP-13 and TIMP-1 determinations were carried out by immunodot blots and immunowestern blots. RESULTS: In progressive periodontitis, MMP-13 and TIMP-1 remained unchanged between active and inactive sites, but as the TIMP-1 relative levels increased together with MMP-13 elevation in inactive samples, an inverse correlation was observed in active sites. Besides, MMP-13 was undetectable in healthy controls. CONCLUSION: Chronic periodontitis is characterized by increased MMP-13 expression. During disease progression, active sites tended to decrease TIMP-1 levels in association with MMP-13 elevation.

A sorbent tube for oral malodour monitoring.

Volatile sulphur compounds (VSCs) and particularly hydrogen sulphide are considered as the predominant gases causing oral malodour. In this paper, a simple alarm sensor has been developed for VSCs determination in mouth air. The device consists of a glass tube packed with a solid sensing phase. The VSCs react with the sensing phase to produce a change in the colour of the sensor visible with a naked eye. Different "reagents" were investigated to develop the sensing phase (neocuproine + Cu(II), bathocuproine + Cu(II), resazurin, 2,6-dichlorophenolindophenol and lead acetate), finding the neocuproine + Cu(II) as the best for our purposes. Also, different substrates such as Amberlite XAD-4 and XAD-7 and different trademarks of silica gel were tested as solid supports, being selected the silica gel. A device consisting of a glass tube packed with the sensing phase was optimized and tested with halitosis patients as a rapid illness test and the results compared with those obtained with a commercially available instrument, the Halimetertrade mark, used for the determination of VSCs in mouth air. The results exhibited acceptable agreement between the proposed "qualitative" alarm sensor and a commercially available technique selected as reference, showing the possibility of using this "visual sensor" to control the halitosis and its evolution with an eventual treatment, by the own patient.