Tobacco Upregulates P. gingivalis Fimbrial Proteins Which Induce TLR2 Hyposensitivity

Tobacco smokers are more susceptible to periodontitis than non-smokers but exhibit reduced signs of clinical inflammation. The underlying mechanisms are unknown. We have previously shown that cigarette smoke extract (CSE) represents an environmental stress to which P. gingivalis adapts by altering the expression of several virulence factors - including major and minor fimbrial antigens (FimA and Mfa1, respectively) and capsule - concomitant with a reduced pro-inflammatory potential of intact P. gingivalis.We hypothesized that CSE-regulation of capsule and fimbrial genes is reflected at the ultrastructural and functional levels, alters the nature of host-pathogen interactions, and contributes to the reduced pro- inflammatory potential of smoke exposed P. gingivalis. CSE induced ultrastructural alterations were determined by electron microscopy, confirmed by Western blot and physiological consequences studied in open-flow biofilms. Inflammatory profiling of specific CSE-dysregulated proteins, rFimA and rMfa1, was determined by quantifying cytokine induction in primary human innate and OBA-9 cells. CSE up-regulates P. gingivalis FimA at the protein level, suppresses the production of capsular polysaccharides at the ultrastructural level, and creates conditions that promote biofilm formation. We further show that while FimA is recognized by TLR2/6, it has only minimal inflammatory activity in several cell types. Furthermore, FimA stimulation chronically abrogates the pro-inflammatory response to subsequent TLR2 stimulation by other TLR-2-specific agonists (Pam3CSK4, FSL, Mfa1) in an IkappaBalpha- and IRAK-1-dependent manner.These studies provide some of the first information to explain, mechanistically, how tobacco smoke changes the P. gingivalis phenotype in a manner likely to promote P. gingivalis colonization and infection while simultaneously reducing the host response to this major mucosal pathogen

Bond strength of different endodontic sealers to dentin: push-out test

OBJECTIVE: The aim of this in vitro study was to evaluate the bond strength of different root canal sealers to dentin. MATERIAL AND METHODS: Forty extracted single-rooted human teeth were examined and the coronal and middle thirds of the canals were prepared with a 1.50 mm post drill (FibreKor Post System, Pentron). The teeth were allocated in two experimental groups, irrigated with 2.5% NaOCl+17% EDTA or saline solution (control group) and instrumented using Race rotary files (FKG) to a size #40 at the working length. Then, the groups were divided into four subgroups and filled with Epiphany sealer (Group 1), EndoREZ (Group 2), AH26 (Group 3) and Grossman's Sealer (Group 4). After 2 weeks of storage in 100% humidity at 37ºC, all teeth were sectioned transversally into 2-mm-thick discs. Push-out tests were performed at a cross-head speed of 1 mm/min using a universal testing machine. The maximum load at failure was recorded and expressed in MPa. RESULTS: Means (±SD) in root canals irrigated with 2.5% NaOCl and 17% EDTA were: G1 (21.6±6.0), G2 (15.2±3.7), G3 (14.6±4.5) and G4 (11.7±4.1).Two-way ANOVA and Tukey's test showed the highest bond strength for the Epiphany's group (p< 0.01) when compared to the other tested sealers. Saline solution decreased the values of bond-strength (p<0.05) for all sealers. CONCLUSION: Epiphany sealer presented higher bond strength values to dentin in both irrigating protocols, and the use of 2.5% NaOCl and 17% EDTA increased the bond strength values for all sealers

Periodontal Health Knowledge and Smoking are Associated with Periodontal Treatment Need according to Tooth Brushing Levels

Objective: The aim of this study is to determine whether periodontal health knowledge is associated with frequency of tooth brushing and periodontal treatment need. Methods: Four hundred and two subjects participated in the study. Data on sociodemographic vari-ables (age, gender, marital status, income, and education), general health, smoking behaviour, tooth cleaning habits and knowledge on periodontal health/disease were collected with a questionnaire. Periodontal treatment need was examined using the Community Periodontal Index of Treatment Needs (CPITN). According to the CPITN scores, the treatment needs were grouped as minimum (CPITN = 0), low-level (CPITN = 1−2), or high-level (CPITN = 3−4). Results: Statistical differences were found between the frequency of tooth brushing and smoking status, marital status, periodontal health knowledge and periodontal treatment needs. Gender (females), place of residence (urban areas), education and periodontal health knowledge had positive relationship with tooth brushing frequency, while smoking and periodontal treatment need had negative relationship. When multivariate logistic regression analysis was applied, age, marriage and poor periodontal know-ledge were associated with increased low-level periodontal treatment needs, and age, marriage and smoking were associated with increased high-level periodontal treatment need. Conclusion: In the limits of this study, we suggest that gender, smoking habits, marital status, place of residence, education and periodontal health knowledge are determining factors related to tooth brush-ing frequency. Periodontal knowledge and smoking are associated with periodontal treatment needs. Keywords: Periodontal health knowledge, periodontal treatment need, smoking, tooth brushing levels "Los Conocimientos de Salud Periodontal y el Hábito de Fumar se Encuentran Asociados con la Necesidad de Tratamiento Periodontal de Acuerdo con los Niveles de Cepillado Dental" RESUMEN Objetivo: El objetivo de este estudio fue determinar si el conocimiento de salud periodontal se halla asociado con la frecuencia del cepillado dental y la necesidad de tratamiento periodontal. Métodos: Cuatrocientos dos sujetos participaron en el estudio. Mediante encuestas, se recogieron datos sobre las variables sociodemográficas (edad, género, estado civil, ingreso, y educación), salud general, comportamiento hacia el fumar, hábitos de limpieza de los dientes, y conocimientos en relación con la enfermedad/salud periodontal. Se examinó la necesidad de tratamiento periodontal usando Sin embargo el Índice de Necesidades de Tratamiento Periodontal de la Comunidad (CPITN), De conformidad con las puntuaciones de CPITN, las necesidades de tratamiento se clasificaron como mínimas (CPITN = 0), bajo nivel (CPITN = 1-2), o alto nivel (CPITN = 3-4). Resultados: Se encontraron diferencias estadísticas entre la frecuencia del cepillado dental con el estatus en torno al hábito de fumar, estado civil, conocimiento de salud periodontal y necesidades del tratamiento periodontales. El género (las hembras), lugar de residencia (las áreas urbanas), la edu-cación y el conocimiento de salud periodontal guardaron una relación positiva con la frecuencia del cepillado dental, mientras que el fumar y la necesidad de tratamiento periodontal, guardaban una relación negativa. Al aplicar el análisis de regresión logística multivariante, se halló que la edad, el matrimonio y el pobre conocimiento periodontal se encuentran asociados con el aumento de la necesidad de de alto nivel. Conclusión: En los límites de este estudio, se sugiere que el género, hábito de fumar, estado civil, lugar de residencia, educación, y conocimientos de salud periodontal, son factores determinantes relaciona-dos con la frecuencia de cepillado dental. El conocimiento periodontal y el hábito de fumar están asociados con las necesidades del tratamiento periodontales. Palabras claves: Conocimientos de salud periodontal, necesidad de tratamiento periodontal hábito de fumar, niveles de cepillado denta