Comparative analysis of bacterial content, levels of lipopolysaccharides and lipoteichoic acid in symptomatic and asymptomatic endodontic infections at different stages of endodontic treatment.

OBJECTIVES: This study aimed to detect the presence of specific bacteria and to evaluate the levels of lipopolysaccharides (LPS) and lipoteichoic acid (LTA) in symptomatic necrotic root canals associated with acute apical abscess (symptomatic group - GI). It also aimed to compare the findings with those presented by asymptomatic necrotic root canals (asymptomatic group - GII) in the different stages of the endodontic treatment. MATERIALS AND METHODS: Microbiological samples were collected from 20 root canals, including purulent collection from acute apical abscesses, before and after chemo-mechanical preparation (CMP) preparation (CMP) with chlorhexidine gel 2% and after 30 days of intracanal medication (ICM) with (Ca[OH]2) + chlorhexidine. The culture method was used to evaluate the efficacy of CMP and ICM. Nested PCR was used to detect the presence of 17 specific bacteria. Levels of LPS were measured by using limulus amebocyte lysate, whereas enzyme-linked immunosorbent assay was used for the quantification of LTA. RESULTS: CMP was effective in reducing the microbial load in both groups (P < 0.05). LPS levels were higher in GI than in GII (P < 0.05). There was a significant reduction in the LPS levels after CMP and ICM (P < 0.05) in GI and GII. LTA levels were significantly reduced in GI after ICM and in GII after CMP and ICM (both P < 0.05). Fusobacterium nucleatum and Enterococcus faecalis were frequently identified in both groups, alone or in combination with each other. CONCLUSION: Different species were detected in all stages of the endodontic treatment. CMP was able to reduce bacterial content and the levels of LPS, but not of LTA in the symptomatic group. High levels of LPS were correlated with spontaneous pain and pain to percussion in the symptomatic group. CLINICAL RELEVANCE: This clinical study showed that chemo-mechanical preparation was able to reduce bacterial load and levels of LPS, but not of LTA in the symptomatic group. Elevated levels of LPS were correlated with the presence of symptomatology.

Oral bacterial decontamination using an innovative prototype for photocatalytic disinfection.

OBJECTIVES: The aim of this study was to evaluate the effectiveness of a prototype photocatalytic device for bacterial decontaminations of the oral cavity. METHODS: Sixty-four subjects (18-65) were selected and randomly assigned to eight groups (n = 8), according to oral disinfection protocol: (G1): distilled water (control); (G2): 1.5% hydrogen peroxide (HP); (G3): 3.0% HP; (G4): 0.12% chlorhexidine (CHX); (G5): Germinator; (G6): 1.5% HP + Germinator; (G7): 3.0%HP + Germinator; (G8): 0.12% CHX + Germinator. Stimulated saliva was collected before and after a 3-min mouthwash and/or Germinator application. The patients were kept relaxed and retained saliva 5-10 min, spitting out into the tube for 3 min. The percentage bacterial reduction was checked by counting the colony-forming units (CFUs) after culturing on blood agar plates. Data were subjected to one-way ANOVA followed by Tukey's post hoc test (α = 5%) for statistical significance. RESULTS: The highest bacterial reduction was observed in groups 3 (3.0% HP), 6 (1.5% HP + Germinator), and 7 (3.0% + Germinator), with no statistically significant difference between them (p > 0.05). Groups 6 (1.5% HP + Germinator) and 8 (0.12% CHX + Germinator) showed higher bacterial reduction than groups 2 (1.5% HP) and 4 (0.12% CHX) (p < 0.05). Finally, group 5 (Germinator) showed higher bacterial reduction than control group (DW) and group 4 (0.12% CHX) (p < 0.05). CONCLUSIONS: The photocatalytic disinfection was effective against oral bacteria and improved the antimicrobial action of 1.5% HP and 0.12%. CLINICAL SIGNIFICANCE: The photocatalytic disinfection can be an alternative protocol to provide the oral decontamination.

Influence of the apical limit of instrumentation and photodynamic therapy on the postoperative pain of lower molars with asymptomatic apical periodontitis.

INTRODUCTION: The aim of present study was to evaluate the influence of apical limit of instrumentation and PDT on the postoperative pain of lower molars with asymptomatic apical periodontitis. METHODS: Forty patients were included in the present study and were divided into 4 groups (n=10), according to apical limit of instrumentation and use of PDT: instrumentation at 0.0 measurement; instrumentation at 0.0 measurement+PDT; instrumentation 1mm beyond 0.0 measurement; instrumentation 1mm beyond 0.0 measurement+PDT. In the PDT, the root canals were filled with 0.01% methylene blue, remaining for 5 min. The low-intensity laser was used with 100 mW, 660-690 nm wavelength), using intra-canal fibre. Root canals were irradiated for 90 s, delivering total dose of 9 J and energy density of 320 J/cm2. After root canal preparation and PDT protocols, root canals were filled with gutta-percha and AH Plus endodontic sealer, being sealed with composite resin.The evaluation of postoperative pain was performed by visual analog scale after 24, 48, 72 hours and 7 days. Data were analysed by specific statistical tests, at level of 5%. RESULTS: No statistical significant difference was observed among experimental groups in all evaluation periods, as well as in the intragroup analysis over time, regarding postoperative pain and analgesic medication consumption (p>0.05). CONCLUSIONS: Apical limit of instrumentation and PDT have no influence on the postoperative pain of lower molars with asymptomatic apical periodontitis.

Influence of ultrasonic activation on antimicrobial activity of a new final irrigant containing glycolic acid: An in vitro study.

This study evaluated the influence of ultrasonic activation (US) on the antimicrobial activity of a new final irrigant containing glycolic acid (GA). Extracted teeth were used, being 70 to counting of colony-forming units (CFUs) and 35 to confocal laser scanning microscopy. Samples were inoculated with Enterococcus faecalis and divided into 7 groups: distilled water + US; 17% EDTA; Qmix; 17% GA; 17% EDTA + US; QMix + US; and 17% GA + US and kept in contact with test solution for 1 min in the groups with or no US. In the CFUs, the highest bacterial reduction was observed in QMix + US group, followed by QMix and GA + US. In the confocal evaluation, the lowest number of viable cells was observed in EDTA + US, with no statistical difference from QMix, QMix + US and GA + US (P > 0.05). The use of US improves the antimicrobial activity of EDTA and GA, being statistically different from the isolated use of these final irrigants in both evaluation tests.

Effect of reciprocating instrumentation on chlorhexidine substantivity on human dentin: chemical analysis followed by confocal laser microscopy

The present research analyzed the reciprocating instrumentation associated to chlorhexidine (CHX) substantivity as its correlation with E. faecalis viability in ex vivo root canals. Eighty extracted single-rooted human teeth were used, being 40 to high-performance liquid chromatography (HPLC) and 40 to confocal laser scanning microscopy (CLSM). In both, teeth were decoronated and the cervical third was prepared. In the CLSM analysis, the root canals were inoculated with E. faecalis for 14 days. Samples were divided into 4 groups (n=10) according to instrumentation technique: no instrumentation and irrigation with distilled water (control); manual instrumentation (K-File); rotary instrumentation (ProTaper Next); and reciprocating instrumentation (Reciproc R25). Two percent chlorhexidine was applied as irrigating substance in experimental groups. Longitudinal grooves resulted in 2 halves root and 20 proof bodies in each group. Samples were divided by chance in two groups (n=10) and the outcomes were evaluated after two days and one week. The retained chlorhexidine and live cells after instrumentation techniques in each evaluation time was measured by HPLC and CLSM, respectively. Specific analysis was applied for experimental tests (p≤0.05). Both rotary as well as reciprocating techniques significantly reduced the amount of chlorhexidine on dentin in all observation periods (p<0.05). After evaluation times, all experimental groups presented lower live cells compared to control, but without statistically difference. Intragroup comparisons in times of evaluation showed no differences in instrumentation techniques, in chlorhexidine retention and number of live cells (p>0.05). Reciprocating instrumentation does not interfere on chlorhexidine substantivity.

Association between history of orthodontic treatment and sociodemographic factors in adolescents.

The aim of this study was to assess history of orthodontic treatment and its determinants in adolescents. This was a crosssectional study conducted in the city of Passo Fundo, Brazil, on a representative sample of adolescents aged 15 to 19 years, regularly enrolled in 20 high schools. A structured questionnaire was applied to assess demographic, behavioral and health variables. The association between history of orthodontic treatment and the dependent variables was analyzed by the chi-square test or Fisher's exact test. Additionally, multivariate regression with robust variance was performed. A total 736 students were examined and interviewed, of whom 57. 6% had undergone orthodontic treatment, while 42. 4% had not. In the multivariable analysis, the following variables were significantly associated with history of orthodontic treatment: female (PR= 1. 26; 95% CI: 1. 11-1. 43), white (PR= 1. 32; 95% CI: 1. 11-1. 56), mothers with higher level of education (PR=1. 49; 95% CI: 1. 28 -1. 74), tooth loss (PR=1. 21; 95% CI: 1. 06-1. 39), and concern about oral health (PR=0. 69; 95% CI: 0. 61-0. 78). Attending a private school was not significantly associated with history of orthodontic treatment (p>0. 05). This study found a high rate for history of orthodontic treatment among adolescents, associated with gender, ethnicity, adolescent's mother with higher education, and tooth loss. Concern about oral health was a protective factor for orthodontic treatment.

Esse estudo objetivou verificar o histórico de tratamento ortodontico e seus fatores associados. Esse estudo transversal foi conduzido na cidade de Passo Fundo, Brasil, com uma amostra representativa dos adolescentes regularmente matriculados no ensino médio, com idades entre 15 e 19 anos, de 20 escolas. Um questionário estrutura foi aplicado para acessar variáveis demográficas, comportamentais e de saúde. As associações entre histórico de tratamento ortodontico e as variáveis independentes foram analisadas pelos testes de qui-quadrado ou exato de Fisher. Além disso, regressão multivariada com variáncia robusta foi realizada. 736 estudantes foram examinados e entrevistados. Tratamento ortodontico foi realizado por 57,6% dos adolescentes, enquanto que 42,4% dos participantes nao o mencionaram. Na análise multivariada, as seguintes variáveis estiveram significativamente associadas com histórico de tratamento ortodôntico: sexo feminino (PR= 1,26; 95%CI: 1,11-1,43), branco (PR= 1,32; 95%CI: 1,11-1,56), mâes com alto nivel educacional (PR=1,49; 95%CI: 1,28-1,74), perda dentária (PR=1,21; 95%CI: 1,06-1,39) epreocupaçâo com a saúde bucal (PR=0,69; 95%CI: 0,61-0,78). Ir a uma escola fiprivada nao esteve significativamente associado com histórico de tratamento ortodôntico (p>0,05). Esse estudo demonstrou que altos niveis de histórico de tratamento ortodôntico são encontrados em adolescentes e isso está associado com sexo, etnia, alta escolaridade da mae do adolescente eperda dentária. Preocupaçâo com a saúde bucal mostrou-se como um fator protetorpara o tratamento ortodôntico.

Association between history of orthodontic treatment and sociodemographic factors in adolescents / Associação entre histórico de tratamento ortodôntico e fatores sociodemográficos em adolescentes

The aim of this study was to assess history of orthodontic treatment and its determinants in adolescents. This was a crosssectional study conducted in the city of Passo Fundo, Brazil, on a representative sample of adolescents aged 15 to 19 years, regularly enrolled in 20 high schools. A structured questionnaire was applied to assess demographic, behavioral and health variables. The association between history of orthodontic treatment and the dependent variables was analyzed by the chisquare test or Fisher's exact test. Additionally, multivariate regression with robust variance was performed. A total 736 students were examined and interviewed, of whom 57.6% had undergone orthodontic treatment, while 42.4% had not. In the multivariable analysis, the following variables were significantly associated with history of orthodontic treatment: female (PR= 1.26; 95% CI: 1.11 ­ 1.43), white (PR= 1.32; 95% CI: 1.11 ­ 1.56), mothers with higher level of education (PR=1.49; 95% CI: 1.28 ­ 1.74), tooth loss (PR=1.21; 95% CI: 1.06 ­ 1.39), and concern about oral health (PR=0.69; 95% CI: 0.61 ­ 0.78). Attending a private school was not significantly associated with history of orthodontic treatment (p>0.05). This study found a high rate for history of orthodontic treatment among adolescents, associated with gender, ethnicity, adolescent's mother with higher education, and tooth loss. Concern about oral health was a protective factor for orthodontic treatment (AU)

Esse estudo objetivou verificar o histórico de tratamento ortodôntico e seus fatores associados. Esse estudo transversal foi conduzido na cidade de Passo Fundo, Brasil, com uma amostra representativa dos adolescentes regularmente matricu lados no ensino médio, com idades entre 15 e 19 anos, de 20 escolas. Um questionário estrutura foi aplicado para acessar variáveis demográficas, comportamentais e de saúde. As associações entre histórico de tratamento ortodôntico e as variáveis independentes foram analisadas pelos testes de quiquadrado ou exato de Fisher. Além disso, regressão multivariada com variância robusta foi realizada. 736 estudantes foram examinados e entrevistados. Tratamento ortodôntico foi reali zado por 57,6% dos adolescentes, enquanto que 42,4% dos participantes não o mencionaram. Na análise multivariada, as seguintes variáveis estiveram significativamente associadas com histórico de tratamento ortodôntico: sexo feminino (PR= 1,26; 95%CI: 1,11 ­ 1,43), branco (PR= 1,32; 95%CI: 1,11 ­ 1,56), mães com alto nível educacional (PR=1,49; 95%CI: 1,28 ­ 1,74), perda dentária (PR=1,21; 95%CI: 1,06 ­ 1,39) e preocupação com a saúde bucal (PR=0,69; 95%CI: 0,61 ­ 0,78). Ir a uma escola privada não esteve significativamente associado com histórico de tratamento ortodôntico (p>0,05). Esse estudo demonstrou que altos níveis de histórico de tratamento ortodôntico são encontrados em adolescentes e isso está associado com sexo, etnia, alta escolaridade da mãe do adolescente e perda dentária. Preocupação com a saúde bucal mostrouse como um fator protetor para o tratamento ortodôntico (AU)

Effectiveness of final decontamination protocols against Enterococcus faecalis and its influence on bond strength of filling material to root canal dentin.

AIM: The aim of this study was to evaluate the effectiveness of final decontamination protocols against Enterococcus faecalis and their influence on bond strength of filling material to root canal dentin. MATERIAL AND METHODS: Ninety root canals were enlarged with ProTaper system and inoculated with E. faecalis for 15days. Sixty samples were randomly divided into six groups (n=10) and subjected to following protocols: G1-distilled water(control), G2-2% chlorhexidine, G3-QMix, G4-6.5% grape seed extract, G5-photodynamic therapy with optical fiber and G6-photodynamic therapy without optical fiber. The percentage of bacterial reduction was checked by counting of CFUs. The remaining 30 samples were subjected to the same decontamination protocols (n=5) and filled with gutta-percha and AH Plus sealer in order to perform the push-out test. Data from both tests were subjected to one-way ANOVA followed by Tukey's post hoc procedure (α=0.05). RESULTS: The greatest bacterial reduction was observed for 2% chlorhexidine, QMix and 6.5% grape seed extract, with no statistically significant difference between them. Photodynamic therapy, with and without optical fiber, demonstrated a significantly higher reduction than distilled water, with no statistically significant difference between them (p<0.05). For the push-out test, final decontamination protocols showed similar bond strength values (p<0.05), with the highest incidence of cohesive failure in all groups. CONCLUSIONS: The tested final decontamination protocols showed effectiveness against E. faecalis and did not interfere with the bond strength of filling material to root canal dentin.