Decontamination of Gutta-percha Cones employed in Endodontics / Descontaminação de cones de guta-percha empregados em endodontia

ABSTRACT The guttapercha cones used in endodontic treatment are produced in aseptic conditions and their composition includes zinc oxide, which is responsible for antibacterial activity. However, there is the possibility of microbial contamination by manipulation, aerosol or during storage. Although several chemical agents have been tested for their decontamination, there is no consensus on the best disinfection protocol to be used. The aim of this study was to evaluate the decontamination of guttapercha cones contaminated with the bacteria Enterococcus faecalis, by using chlorhexidine digluconate (CHX) and sodium hypochlorite (NaClO) at different concentrations for short exposure times. For this purpose, guttapercha cones (size 40) were selected at random from a sealed box and immersed for 1 min in a microbial suspension. Then they were immersed in specific Petri dishes for different groups containing: CHX 2%, NaClO 1% or NaClO 2.5% for 30 s or 1 min, and subsequently placed in tubes containing BHI broth. After incubating the tubes for 48 h, it was observed that 1% and 2.5% NaClO and 2% CHX were effective for decontaminating the cones at those exposure time intervals. Microbial growth was detected in one of the replicates of the group with CHX applied for 30 s. To prevent the possibility of failures at this stage, the exposure time of guttapercha cones to the decontaminating agent should not be reduced.

RESUMO Os cones de gutapercha utilizados no tratamento endodôntico são produzidos em condições assépticas e possuem óxido de zinco em sua composição, responsável pela atividade antibac te riana. No entanto, existe a possibilidade de contaminação microbiana por manipulação, aerossol ou seu armazenamento. Embora vários agentes químicos já tenham sido testados para sua descontaminação, não há consenso sobre o melhor proto colo de desinfecção a ser usado. Nosso objetivo foi avaliar a descontaminação de cones de gutapercha contaminados com a bactéria Enterococcus faecalis, utilizando digluconato de clorexidina (CHX) e hipoclorito de sódio (NaClO) em diferentes concentrações e tempos de exposição curtos. Para esse fim, 40 cones de gutapercha foram selecionados aleatoriamente, de uma caixa selada e imersos por 1 min em uma suspensão microbiana. Em seguida, foram imersos em placas de Petri específicas para diferentes grupos contendo: CHX 2%, NaClO 1% ou 2,5%, nos tempos de exposição de 30s e 1min e subseqüentemente imersos em tubos contendo caldo BHI. Após incubação dos tubos por 48 h, observouse que NaClO 1% e 2,5% e CHX 2% foram eficazes para a descontaminação dos cones nesses intervalos de tempo de exposição. Em uma das réplicas do grupo com CHX aplicado por 30s foi detectado crescimento microbiano. O tempo de exposição dos cones de gutapercha ao agente de desconta minação não deve ser reduzido para evitar a possibilidade de falhas nesse estágio.

Efeito do extrato da própolis e do digluconato de clorexidina sobre a formação de biofilme por Candida albicans em resina acrílica / Effect of propolis extract and chlorhexidine digluconate on the biofilm formation by Candida albicans in acrylic resin

Objetivo: avaliar in vitro a ação antimicrobiana do extrato da própolis (EP) e do digluconato de clorexidina (DCHX) na formação de biofilme por Candida albicans em resina acrílica termopolimerizada. Métodos: o efeito do EP e DCHX em biofilmes de C. albicans foi avaliado pela quantificação de Unidades Formadoras de Colônias (UFCs), pela quantificação da biomassa por cristal violeta e de polissacarídeos por safranina. Para tanto, C. albicans foram pré-aderidas em corpos de prova e somente em microplacas de poliestireno, posteriormente foi realizado o tratamento com diferentes concentrações de EP (221 µg/mL e 443 µg/mL) e DCHX (0,25% e 0,5%). Resultados: foi demonstrada uma redução significativa na formação de biofilme por C. albicans com ambas as substâncias testadas e em todas as concentrações. Conclusão: de acordo com os resultados, observou-se que ambos os tratamentos foram eficazes na redução do biofilme e que o EP, por ser um produto natural, de baixo custo e sem afeitos colaterais, representa uma alternativa inovadora para o tratamento da candidose oral em usuários de próteses removíveis.(AU)

Objective: to evaluate in vitro the antimicrobial action of propolis extract (EP) and chlorhexidine digluconate (DCHX) in the biofilm formation by Candida albicans in thermopolymerized acrylic resin. Methods: the effect of EP and DCHX on C. albicans biofilms were evaluated through the quantification of Colony Forming Units (CFU's), the quantification of biomass by violet crystal and polysaccharides by safranin. For this purpose, C. albicans were pre-adhered to specimens and only on polystyrene microplates and subsequently the treatment was performed with different concentrations of EP (221 µg/mL and 443 µg/mL) and DCHX (0.25% and 0,5%). Results: a significant reduction in the biofilm formation by C. albicans was demonstrated, with both substances tested and in all concentrations. Conclusion: according to the results, it was observed that both treatments were effective in reducing biofilm and EP, being a natural product, low cost and without side effects, represents an innovative alternative for the treatment of oral candidiasis in users removable dentures.(AU)

Evaluation of the physical and antifungal effects of chlorhexidine diacetate incorporated into polymethyl methacrylate

Abstract This study aimed to evaluate the physical properties and antifungal activities of polymethyl methacrylate (PMMA) acrylic resins after the incorporation of chlorhexidine diacetate salt (CDA). Methodology: First, acrylic resin specimens were fabricated with Vipi Cor® and DuraLay® resins with and without the incorporation of 0.5%, 1.0% or 2.0% CDA. The residual monomer and CDA release were measured at intervals ranging from 2 hours to 28 days using ultraviolet spectrometry combined with high-performance liquid chromatography. The antifungal activity against C. albicans was evaluated with the agar diffusion method. Fourier transform infrared spectroscopy was used to analyze the degree of resin conversion. Finally, the water sorption values of the resins were also measured. Results: The incorporated CDA concentration significantly changed the rate of CDA release (p<0.0001); however, the brand of the material appeared to have no significant influence on drug release. Subsequently, the inhibition zones were compared between the tested groups and within the same brand, and only the comparisons between the CDA 2% and CDA 1% groups and between the CDA 1% and CDA 0.5% groups failed to yield significant differences. Regarding the degrees of conversion, the differences were not significant and were lower only in the CDA 2% groups. Water sorption was significantly increased at the 1.0% and 2.0% concentrations. Conclusions: We concluded that the incorporation of CDA into PMMA-based resins enabled the inhibition of C. albicans growth rate, did not alter the degrees of conversion of the tested resins and did not change the release of residual monomers.

In vitro evaluation of Eugenia dysenterica in primary culture of human gingival fibroblast cells

Abstract: Eugenia dysenterica is a Brazilian tree investigated for its properties and bioactive compounds, which are believed to have both pharmacological and phytochemical therapeutic effects. The leaves of this tree contain tannins, flavonoids, terpenes, and saponins, with reportedly beneficial effects to the human body. Despite these therapeutic applications, its effects have never been tested on oral tissues. Therefore, the aim of the present study was to evaluate the cytotoxic and antioxidant effects and the anti-inflammatory and repair properties of the acetone fraction of E. dysenterica on primary culture of human gingival fibroblasts and on the immortalized murine macrophage cell line (RAW 264.7). For this purpose, a metabolic activity assay, a wound healing assay, a nitric oxide assay, and RT-qPCR were performed. The assays revealed a cytoprotective effect of this plant, suggested by the increase in the expression of SOD1 and NRF2. An antioxidant potential effect was observed in the DPPH• assay. However, the fraction of E. dysenterica did not show anti-inflammatory activity. In conclusion, Eugenia dysenterica may promote cytoprotection when associated with chlorhexidine digluconate because of its antioxidant effect. However, additional studies are necessary on other human dental tissues using other parts of the plant in order to develop a possible mouthwash to assist patients with oral disorders.

Atividade antimicrobiana de Stevia rebaudiana Bertoni e de adoçantes não calóricos sobre bactérias cariogênicas: estudo in vitro / Antimicrobial activity of Stevia rebaudiana Bertoni and non-caloric sweeteners on cariogenic bacteria: in vitro study

Objetivo: avaliar a atividade antimicrobiana in vitro da planta Stevia rebaudiana Bertoni e de adoçantes não calóricos sobre o crescimento de Streptococcus mutanse Lactobacillus casei, micro-organismos cariogênicos presentes na cavidade bucal. Materiais e método: o estudo foi realizado utilizando as cepas padrões de S.mutans (UA159) e L. casei (ATCC7469). Foram avaliados diferentes compostos não calóricos substitutos dasacarose nas concentrações de 1%, 5% e 10%: eritritol(ER), Fit Sucralose® (SU), Stevita® (ST), solução de Steviarebaudiana Bertoni (SSr) e, como controle positivo,digluconato de clorexidina (DC). A análise do efeito inibitório desses compostos no crescimento das bactériasfoi feita por meio da técnica de difusão em ágar. Resultado:observou-se que existe um efeito inibitório decrescimento de ambos os micro-organismos por parte da SSr e do ER, enquanto os demais adoçantes testa dosnão tiveram efeito inibitório sobre esses micro-organismos.Conclusão: os resultados demonstram que SSR eER apresentam efeito inibidor no crescimento das cepastestadas de S. mutans e L. casei. (AU)

Objective: The study evaluated the in vitro antimicrobial activity of the Stevia rebaudiana Bertoni plant and non-caloric sweeteners on the growth of Streptococcus mutans and Lactobacillus casei, which are cariogenic microorganisms present in the oral cavity. Materials and method: The study was conducted using the standard strains of S. mutans (UA159) and L. casei (ATCC7469). Different non-caloric compounds were evaluated at concentrations of 1%, 5%, and 10%: erythritol (ER), Fit Sucralose™ (SU), Stevita™ (ST), Stevia rebaudiana Bertoni solution (SSr), and chlorhexidine digluconate (CD) as positive control. The inhibitory effect of these compounds on the growth of bacteria were analyzed by the agar diffusion technique. Result: There was a growth inhibition effect for both microorganisms by SSr and ER, whereas the other sweeteners tested had no inhibitory effect on the microorganisms. Conclusion: The results showed that SSr and ER present an inhibitory effect on the growth the strains tested of S. mutans and L. casei. (AU)

Cymbopogon citratus essential oil: effect on polymicrobial caries-related biofilm with low cytotoxicity

Abstract The objective of this study was to evaluate the effects of Cymbopogon citratus essential oil and its main compound (citral) against primary dental colonizers and caries-related species. Chemical characterization of the essential oil was performed by gas chromatography/mass spectroscopy (GC/MS), and the main compound was determined. Antimicrobial activity was tested against Actinomyces naeslundii, Lactobacillus acidophilus, S. gordonii, S. mitis, S. mutans, S. sanguinis and S. sobrinus. Minimum inhibitory and bactericide concentrations were determined by broth microdilution assay for streptococci and lactobacilli reference, and for clinical strains. The effect of the essential oil on bacterial adhesion and biofilm formation/disruption was investigated. Negative (without treatment) and positive controls (chlorhexidine) were used. The effect of citral on preformed biofilm was also tested using the same methodology. Monospecies and microcosm biofilms were tested. ANOVA or Kruskal-Wallis tests were used (α=0.05). Cytotoxicity of the essential oil to human keratinocytes was performed by MTT assay. GC/MS demonstrated one major component (citral). The essential oil showed an inhibitory effect on all tested bacterial species, including S. mutans and L. acidophilus. Essential oil of C. citratus (10X MIC) reduced the number of viable cells of lactobacilli and streptococci biofilms (p < 0.05). The essential oil inhibited adhesion of caries-related polymicrobial biofilm to dental enamel (p < 0.01). Citral significantly reduced the number of viable cells of streptococci biofilm (p < 0.001). The essential oil showed low cytotoxicity to human keratinocytes. Based on these findings, this study can contribute to the development of new formulations for products like mouthwash, against dental biofilms.

Effect of Ocimum gratissimum in Mouthrinses on De Novo Plaque Formation. A Randomized Clinical Trial

Resumo O objetivo do presente estudo foi avaliar clinicamente em humanos o efeito antiplaca de Ocimum gratissimum (Og). Quinze adultos saudáveis participaram deste estudo cruzado, duplo-cego, por meio de um modelo de acúmulo de placa parcial de 3 dias. Os voluntários aboliram qualquer método mecânico de higiene oral e foram inicialmente designados para usar os seguintes enxaguatórios bucais: água destilada (solução AD), digluconato de clorexidina a 0,12% (solução CLX) ou 10% Og (solução Og). O índice de placa (IPL) foi registrado em todos os dentes inferiores no final do experimento e os testes estatísticos Kruskal-Wallis (α=0,05) e Mann-Whitney (α=0,05) foram utilizados para estimar a diferença entre os grupos. Os resultados clínicos demonstraram diferença estatisticamente significante entre os três grupos (p<0,05), favorecendo os grupos CLX e Og; entretanto o grupo CLX foi mais efetivo que o grupo Og (p<0,05). Os enxaguatórios bucais contendo digluconato de clorexidina e Og a 10% foram capazes de reduzir a formação de nova placa bacteriana, mas Og mostrou resultados mais limitados em comparação ao digluconato de clorexidina.

Abstract The aim of this study was to evaluate the antiplaque effect of Ocimum gratissimum (Og) by in vivo investigation. Fifteen healthy volunteers participated in a crossover, double-blind clinical study, using a 3-day partial-mouth plaque accumulation model. The participants abolished any method of mechanical oral hygiene and they were randomly assigned to initially use just the following mouthrinses: distilled water (DW solution), 0.12% chlorhexidine digluconate (CLX solution) or 10% Og (Og solution). The plaque index (PLI) was recorded in all mandibular teeth at the end of the trial and the Kruskal-Wallis (α=0.05) and Mann-Whitney (α=0.05) tests were used to estimate the difference among groups. The clinical results showed statistically significant difference among the groups (p<0.05), favoring the CLX solution and Og solution, but the first was more effective (p<0.05). The mouthrinses containing 0.12% chlorhexidine digluconate and 10% Og were able to inhibit plaque re-growth, however Og showed more limited results in comparison to CLX.

in vitro comparison of antimicrobial effects of curcumin-based photodynamic therapy and chlorhexidine, on aggregatibacter actinomycetemcomitans

Introduction: Considering the importance of prevention in periodontal diseases and the important role of Aggregatibacter actinomycetemcomitans in induction and progression of these diseases, the aim of the present in vitro study was to compare the antimicrobial effects of chlorhexidine digluconate [CHX], curcumin and light-emitting diode [LED] laser, on this bacterium

Methods: Antimicrobial activity of curcumin [5 mg/ml], CHX [2%], LED [120 J/cm[2]] and LED + curcumin [120 J/cm[2] + 2.5 mg/ml] against A. actinomycetemcomitans were tested in vitro, using micro-broth dilution test. One-way analysis of variance [ANOVA] and Tukey's HSD tests served for statistical analysis

Results: Regarding the minimum inhibitory concentration [MIC], CHX had a significantly lower MIC than curcumin [P<0.05]. Sorted out by bacterial growth from lowest to highest, were CHX, LED + curcumin, curcumin, and LED groups. All the differences were found to be statistically significant [P<0.05] except for the LED group

Conclusion: We conclude that curcumin is an effective substance in preventing the growth of A. actinomycetemcomitans, whose impact is reinforced when used simultaneously with photodynamic therapy [PDT]

Effect of green tea as a protective measure against dental erosion in coronary dentine

Abstract The aim of this study was to evaluate the effect of green tea as a protective measure on eroded dentin. Disks of human coronary dentin were selected based on surface hardness and randomly assigned to 3 groups (n = 10): DW - distilled water, CHX - 0.2% chlorhexidine digluconate, and GT - green tea. The disks were allowed to acquire pellicle for 2 hours and were then subjected to 3 cycles per day of demineralization (C6H8O7 0.05 M, pH 3.75, 60 s), treatment (DW or CHX or GT, 5 min) and remineralization (artificial saliva, 60 min) over a period of 3 days. Changes in the dentin were determined by loss of surface hardness (%SHL) and mechanical profilometry analysis at the end of each day. Data were analyzed by two-way ANOVA followed by Tukey’s test for %SHL and profilometry (p < 0.05). Significant reductions in dentin hardness loss were observed only for the CHX group when compared to the DW group (p < 0.05). However, there was no significant difference between the CHX and GT groups (p > 0.05). A significant difference was observed between DW and GT treatments for wear and roughness measurements (p < 0.05). The green tea extract solution was able to reduce the wear and roughness caused by dentin erosion under the conditions of this study.

Antimicrobial activity and substantivity of Uncaria tomentosa in infected root canal dentin

Abstract The aim of this study was to analyze the antimicrobial activity and substantivity of Uncaria tomentosa Willd DC (cat's claw, CC) in root dentin contaminated with Enterococcus faecalis. Forty-eight human premolars were contaminated with E. faecalis (ATCC 29212) and randomly divided into four groups according to the irrigant used during chemomechanical preparation (CMP): CC group: 2% CC gel; CHX group: 2% chlorhexidine digluconate gel (CHX); NaOCl group: 5.25% sodium hypochlorite (NaOCl); and SS group: sterile saline (SS). Microbiological samples were collected before (S1) and after (S2) CMP and after 7 days (S3). Colony-forming units (CFU/mL) at the different sampling times and comparisons among the groups were statistically analyzed by Wilcoxon and Kruskal-Wallis tests (p < 0.05). Significant bacterial reduction was achieved in all groups after CMP (p < 0.05). Results show no significant difference between S3 and S2 (p > 0.05) in the CC and CHX groups. Bacterial load was higher in S3 than in S2 samples (p < 0.05) in the NaOCl and SS groups. Our results suggest antibacterial effect of 2% CC gel against E. faecalis in infected dentin, in addition to antibacterial substantivity of 2% CC and 2% CHX up to 7 days.

Antimicrobial activity of different disinfectants against cariogenic microorganisms

Abstract The aim of this study was to assess the in vitro antimicrobial effects of chlorhexidine digluconate (CHX), polyhexamethylene biguanide (PHBM), and octenidine dihydrochloride (OCT) on cariogenic microorganisms by using their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). CHX, PHBM, and OCT were diluted in distilled water to the final test concentrations. Using the in-tube dilution method, Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus rhamnosus, and Actinomyces viscosus were cultivated on blood agar and Mueller-Hinton broth (MHB) at 37°C for 48 h. They were read using a spectrophotometer to detect MIC. To determine MBC, samples in the range of the turbidity threshold after 24 h were transferred onto blood agar and evaluated for growth after 24 h. Different MICs and MBCs were observed in all disinfectants against each microorganism. The lowest MIC and MBC against S. mutans (60 mg/L) were obtained from PHBM. The lowest values against L. rhamnosus (15 mg/L, 30 mg/L), A. viscosus (30 mg/L), and L. acidophilus (15 mg/L, 30 mg/L) were determined by OCT. PHBM and OCT have the potential to be replaced with CHX because they were effective against cariogenic microorganisms.

Influence of Cariogenic Challenge on Bond Strength Stability of Dentin

The aim of this study was to evaluate the effect of cariogenic challenge on the microtensile bond strength values (μTBS) of dentin pre-treated with chlorhexidine digluconate (CHX) or sodium hypochlorite (NaOCl). Thirty-six sound molars were selected and randomly assigned to 3 dentin pre-treatments (distilled water - control, 2% CHX and 10% NaOCl) and 4 aging protocols (24h control, biofilm without cariogenic challenge, biofilm with cariogenic challenge, and 18-month water storage). The same etch-and-rinse adhesive system and composite resin were used for all groups (n=30 beams). For the biofilm groups, dental microcosm biofilms originated from saliva of a healthy donor were grown on the samples with a defined medium enriched with mucin, with or without 10% sucrose, according to the group. After the experimental period, the microtensile test was performed. Data were analyzed with ANOVA followed by Tukey test (p<0.05). The pre-treatment did not influence μTBS for all aging conditions (p=0.188), but the type of aging affected the bond strength (p<0.001). Cariogenic challenge and water storage aging affected the bond stability resulting in a decrease of the μTBS, but the pre-treatments did not influence the μTBS.

O objetivo neste estudo foi avaliar o efeito do desafio cariogênico na resistência de união (RU) da dentina pré-tratada com clorexidina (CRX) ou hipoclorito de sódio (NaOCl). Trinta e seis molares hígidos foram selecionados e randomizados de acordo com 3 pré-tratamentos dentinários (controle, CRX a 2% e NaOCl a 10%) e 4 protocolos de envelhecimento (controle 24h, biofilme sem desafio cariogênico, biofilme com desafio cariogênico, e armazenamento de 18 meses em água). O mesmo sistema adesivo e resina composta foram usados para todos os grupos (n=30). Biofilme dental de microcosmo originado da saliva de doador saudável foi desenvolvido sobre as amostras com meio enriquecido com mucina adicionada ou não com sacarose a 10%, de acordo com o grupo. Após o período experimental, o teste de microtração foi realizado. Os dados de microtração foram analisados com ANOVA a dois fatores e teste de Tukey (p<0,05). O pré-tratamento não influenciou os valores de RU para todos os protocolos de envelhecimento (p=0,188), porém o tipo de envelhecimento influenciou os valores de RU (p<0,001). O desafio cariogênico e o armazenamento em água afetaram a estabilidade adesiva resultando na diminuição dos valores de RU e o pré-tratamento não influenciou os valores de RU.

[In vitro antifungal efficacy of different intracanal irrigant against Candida Albicans]

An intracanal irrigant is essential for a successful root canal therapy. The aim of this study was to compare the antifungal efficacy of 5.25% sodium hypchlorite, 2% chlorhexidine gluconate and 94% carvacrol against Candida albicans in vitro. In this experimental study, after crown removal and canal preparation of 48 extracted human maxillary centreal incisors, they were randomly divided into 3 experimental groups of 14 teeth, plus 3 teeth as positive and 3 as negative controls. A suspension of Candida albicans [ATCC-10261] was injected into the experimental and positive control group root canals. The teeth were then incubated for 72 hours. Then, each group was rinsed with one of the irrigants for 1 minute and samples were taken from the canals and inoculated on plates. After 48 hours of incubation, the colony growth was assessed and colony forming units [CFUs] served as a measure of antifungal activity. Data were analyzed using the Kruskal Wallis test. In carvacrol, sodium hypochlorite and chlorhexidine gluconate groups, 6, 10 and 1 specimen did not show bacterial growth and the mean CFU was 86.3, 53.3 and 271.2 in the mentioned groups, respectively. Carvacrol and 5.25% sodium hypochlorite had similar antifungal efficacy against Candida albicans and this effect was significantly greater than that 2% chlorhexidine gluconate

Antimicrobial activity of different filling pastes for deciduous tooth treatment

Guedes-Pinto paste is the filling material most employed in Brazil for endodontic treatment of deciduous teeth; however, the Rifocort® ointment has been removed. Thus, the aim of this study was to investigate the antimicrobial potential of filling pastes, by proposing three new pharmacological associations to replace Rifocort® ointment with drugs of already established antimicrobial power: Nebacetin® ointment, 2% Chlorhexidine Gluconate gel, and Maxitrol® ointment. A paste composed of Iodoform, Rifocort® ointment and Camphorated Paramonochlorophenol (CPC) was employed as the gold standard (G1). The other associations were: Iodoform, Nebacetin® ointment and CPC (G2); Iodoform, 2% Chlorhexidine Digluconate gel and CPC (G3); Iodoform, Maxitrol® ointment and CPC (G4). The associations were tested for Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), Streptococcus oralis (S. oralis), Enterococcus faecalis (E. faecalis), Escherichia coli (E. coli), and Bacillus subtilis (B. subtilis), using the methods of dilution on solid medium – orifice agar – and broth dilution. The results were tested using statistical analysis ANOVA and Kruskal-Wallis. They showed that all the pastes had a bacteriostatic effect on all the microorganisms, without any statistically significant difference, compared with G1. S. aureus was statistically significant (multiple comparison test of Tukey), insofar as G2 and G3 presented the worst and the best performance, respectively. All associations were bactericidal for E. coli, S. aureus, S. mutans and S. oralis. Only G3 and G4 were bactericidal for E. faecalis, whereas no product was bactericidal for B. subtilis. Thus, the tested pastes have antimicrobial potential and have proved acceptable for endodontic treatment of primary teeth.

How erosive drinks and enzyme inhibitors impact bond strength to dentin

Concern has been raised about the bonding of restorative procedures to an erosive lesion, given the change in organic and inorganic composition and structure of this substrate. This in vitro study evaluated the effect of erosive drinks and an enzyme inhibitor (2% chlorhexidine digluconate – 2% CHX) on bond strength to dentin. Sixty sound human third molars were selected, and the occlusal enamel was flattened, exposing the dentin surface. The specimens were randomly divided into three groups: AS-Artificial saliva (control group), RC- Regular Cola and ZC- Zero Cola. Twenty specimens were immersed in their respective solution for 1 minute, 3 times a day, over the course of 5 days. After acid etching and before bonding with Adper Single Bond 2, half of the samples of each group (n = 10) were treated with 2% CHX, whereas the other half (n = 10) were not, forming the control group (CONV). All the specimens were restored with Filtek Z250 composite resin filled in Tygon tubes (0.48 mm2), yielding six microcylinders for microshear bond strength testing. Three composite resin microcylinders of each specimen were tested after 1 month, and the remaining microcylinders were tested after 6 months. Failure modes were determined using a stereomicroscope (40x). The data were statistically analyzed by three-way ANOVA and Tukey tests (α = 0.05). Overall bonding was reduced after 6 months, regardless of treatment. The 2% CHX enhanced bond strength after 1 month only in the ZC group, and did not enhance bonding performance to demineralized dentin by erosive protocol after 6 months in any group.

Influence of time, toothpaste and saliva in the retention of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes

Objectives: The intraoral transmission of cariogenic and periodontopathogenic species seems to be facilitated by contaminated toothbrushes and other oral hygiene devices. The aim of this investigation was to analyze the in vitro retention and survival rate of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes. The impacts of human saliva and antimicrobial toothpaste on these parameters were further evaluated. Material and Methods: Part I: Four toothbrushes (Colgate 360°, Curaprox CS5460 ultra soft, elmex InterX, Trisa Flexible Head3) were contaminated by S. mutans DSM 20523 or S. sanguinis DSM 20068 suspensions for three minutes. Bacteria were removed from the toothbrushes after either three minutes (T0) or 24 hours (T24) of dry storage and grown on Columbia blood agar plates for the quantification of colony-forming units (CFUs). Part II: The effects of saliva from a caries-active or a caries-inactive person and of toothpaste containing 0.12% chlorhexidine digluconate were also tested. Results: Part I: After three minutes of dry storage, approximately one percent of the bacteria were still detectable on the toothbrushes. After 24 hours, S. sanguinis exhibited a more pronounced decrease in viable cell numbers compared with S. mutans but the differences were not significant (Kruskal-Wallis test, p>0.05). Part II: The addition of human saliva from a caries-active or caries-inactive person slightly increased the retention of both streptococcal species at T0. The use of toothpaste had no influence on the amount of viable streptococci at T0, but it reduced the microbial load after 24 hours of storage. There were only slight nonsignificant differences (p>0.05) between the four toothbrushes. Conclusions: In vitro bacterial retention and survival of S. sanguinis and S. mutans on different toothbrushes occurred. Within the limitations of this study, the use of human saliva or an antimicrobial toothpaste ...

Addition of Chlorhexidine Gluconate to a Glass Ionomer Cement: A Study on Mechanical, Physical and Antibacterial Properties

The objective of this work was to determine the effect of different concentrations of chlorhexidine digluconate (CHX) on setting time, surface hardness, maximum tensile bond strength and antibacterial activity of a glass ionomer cement (GIC). The material used as control was Ketac Molar Easymix GIC. CHX was incorporated into the GIC during its manipulation at concentrations of 0.5, 1.0 and 2.0%. Antimicrobial activity against S. mutans and L. acidophilus was evaluated by means of agar diffusion test. Tensile bond strength data were analyzed statistically using Analysis of variance and Tukey's test. Setting time, Vickers hardness and agar diffusion test were analyzed using Kruskal-Wallis and Mann-Whitney tests at a significance level of 5%. It was observed that adding CHX at concentrations of 1% and 2% increased significantly the setting time of the material (p=0.012 and p=0.003, respectively). There was no significant difference between control and 0.5% CHX groups regarding the setting time. Addition of 2% CHX decreased significantly the surface hardness in relation to the control group (p=0.009), followed by the 1% CHX group (p=0.009). The tensile bond strength of the material also decreased significantly after adding CHX at a concentration of 2% (p=0.001). Addition of CHX promoted formation of an inhibition halo in both bacterial strains for all concentrations. The results showed that the best option for clinical use of GIC with CHX is at 0.5% concentration, since antibacterial activity increased and the physical-mechanical properties remained unchanged.

O objetivo deste trabalho foi determinar o efeito de diferentes concentrações de gluconato de clorexidina (CLX) sobre o tempo de presa, dureza superficial, resistência máxima a tração e atividade antibacteriana de um cimento de ionômero de vidro (CIV). O material utilizado como controle foi o CIV Ketac Molar Easymix. O gluconato de CHX foi incorporado no CIV durante a sua manipulação, em concentrações de 0,5, 1,0 e 2,0%. Atividade antimicrobiana contra S. mutans e L. acidophilus foi avaliada por meio de teste de difusão em ágar. Análise de variância (ANOVA) e teste de Tukey foram usadas para avaliar a resistência a tração do material. Para avaliar tempo de presa, dureza Vickers e teste de difusão em ágar foram usados os testes de Mann-Whitney e Kruskal-Wallis ao nível de significância de 5%. Observou-se que a adição de CHX, em concentrações de 1% e 2%, aumentou significativamente o tempo de presa do material (p = 0,012 e p = 0,003, respectivamente). Não houve diferença significativa entre os grupos controle e CHX 0,5% em relação ao tempo de presa. A adição de 2% de CHX diminuiu significativamente a dureza superficial, em relação ao grupo controle (p = 0,009), seguido pelo grupo 1% de CHX (p = 0,009). A resistência à tração do material também diminuiu significativamente após a adição de CHX a uma concentração de 2% (p = 0,001). A adição de CHX promoveu formação de halo de inibição em ambas as linhagens bacterianas para todas as concentrações. Os resultados mostraram que a melhor opção para o uso clínico de CIV com CHX está numa concentração de 0,5%, uma vez que a atividade antibacteriana aumentada e as propriedades físico-mecânicas permaneceram inalteradas.

Comparación de los efectos antibacterianos de aseos bucales con matrica, Persica® y gluconato de clorhexidina en pacientes de UCI con ventilación mecánica: ensayo clínico doble ciego y aleatorio / Comparison of the antibacterial effects of matrica & PersicaTM and chlorhexidine gluconate mouthwashes in mechanically ventilated ICU patients: a double blind randomized clinical trial

Background:Accumulation of bacteria in the pharynx is one of the risk factors of pneumonia due to ventilation. One of the methods of prevention from accumulation of bacteria in the pharynx is the use of oral solutions. Chlorhexidine is considered as the gold standard, but it has various side effects. Aim:Present study was aimed to determine and compare anti-bacterial effects of the chlorhexidine gluconate 0.2%, herbal mouthwash of Matrica® (chamomile extracts) 10%, PersicaTM 10% and normal saline in intensive care unit patients. Methods:In this double blind randomized clinical trial, 80 patients who were admitted in ICU divided into four groups of 20 patients each one. Researchers applied PersicaTM to group one, chlorhexidine gluconate mouth wash 0.2% to group two and third group received Matrica, finally in the control group, normal saline were used. In order to culturing of Staphylococcus aureusand S. pneumoniae,salivary samples were obtained without any stimulation after six minimums oral rinsing. The data were processed in SPSS17 software and analyzed by appropriate statistical tests. Results:Decreased rate of bacterial colonies after intervention in the whole four groups was significant (p < 0.001). The mouth wash of chlorhexidine (p < 0.001), PersicaTM (p: 0.008) and Matrica (p: 0.01) had a significant antibacterial effect on S. aureusand S. pneumoniae(p < 0.001). Conclusion:Herbal oral mouthwash of persica and matrica has the effect on S. pneumoniae and S. aureusof oropharynx area in mechanically ventilated patients. However, there is a need for further research to be considered as an alternative to chlorhexidine for prevention of VALP in ICU patients.

Introducción:La presencia y acumulación de bacterias en la cavidad oral es un factor de riesgo para el desarrollo de neumonía asociada a ventilación mecánica. Uno de los métodos para prevenir esta acumulación en la faringe es el uso de soluciones orales. Al respecto, clorhexidina es considerada el estándar de oro, pero tiene varios efectos colaterales. Objetivo:Determinar y comparar el efecto antibacteriano de gluconato de chorhexidina al 0,2%, aseo bucal con preparado en base a hierba matrica (extracto de chamomile) al 10%, Persica® al 10% y solución salina fisiológica (NaCl 9%0) en pacientes de la unidad de cuidados intensivos ingresados para ventilación mecánica. Métodos:Ensayo doble ciego, randomizado, sobre 80 pacientes ingresados en UCI, divididos en cuatro grupos de 20 miembros cada uno. El grupo I recibió Persica®, el grupo II aseo bucal con gluconato de clorhexidina al 0,2%, el grupo III recibió matrica y, finalmente, el grupo IV-control recibió solución salina fisiológica. Con la finalidad de cultivar Staphylococcus aureus yS. pneumoniae,se obtuvieron muestras de saliva sin efectuar estímulo alguno tras un mínimo de seis lavados bucales. Los datos fueron procesados en el software SPSS17 y analizados por tests estadísticos apropiados. Resultados:La disminución en el recuento de colonias bacterianas, después de la intervención, fue significativa en los cuatro grupos (p < 0,001). El aseo bucal con clorhexidina (p < 0,001), Persica® (p: 0,008) y matrica (p: 0,01) tuvo un significativo efecto antibacteriano sobre las especies S. aureusy S. pneumoniae(p < 0,001). Conclusión:El aseo bucal con solución en base a hierbas de Persica® y matrica tiene un efecto sobre S. pneumoniae y S. aureusde la cavidad oral en pacientes en régimen de ventilación mecánica. No obstante, se requiere de mayores estudios para considerarlo una alternativa a clorhexidina para la prevención de neumonías en pacientes de UCI.

Tenascin and Fibronectin Expression after Pulp Capping with Different Hemostatic Agents: A Preliminary Study

This study investigated the expression of extracellular matrix glycoproteins tenascin (TN) and fibronectin (FN) in pulp repair after capping with calcium hydroxide (CH), following different hemostasis protocols. Class I cavities with a pulp exposure were prepared in 42 human third molars scheduled for extraction. Different hemostatic agents (0.9% saline solution, 5.25% sodium hypochlorite and 2% chlorhexidine digluconate) were used and pulps were capped with CH cement. After 7, 30 or 90 days, teeth were extracted, formalin-fixed, and prepared for immunohistochemical technique. Hemostatic agents did not influence the expression of TN and FN. Both glycoproteins were found in the entire the pulp tissue and around collagen fibers, but were absent in the mineralized tissues. In the predentin, TN showed positive immunostaining and FN had a variable expression. Within 7 days post-treatment, a slightly more pronounced immunostaining on the pulp exposure site was observed. Within 30 days, TN and FN demonstrated a positive expression around the dentin barrier and at 90 days, a thin and linear expression of TN and FN was delimitating the reparative dentin. In conclusion, hemostatic agents did not influence TN and FN expression. Immunostaining for TN and FN was seen in different regions and periods, demonstrating their role in pulp repair.

Este estudo investigou a expressão das glicoproteínas Tenascina (TN) e Fibronectina (FN) da matriz extracelular no reparo pulpar após capeamento com hidróxido de cálcio (HC), seguindo diferentes protocolos de hemostasia. Cavidades de classe I com exposição pulpar foram preparadas em 42 terceiros molares humanos indicados para extração. Diferentes agentes hemostáticos (solução salina a 0,9%, hipoclorito de sódio a 5,25% e clorexidina a 2%) foram usados e as polpas foram capeadas com cimento de HC. Após 7, 30 ou 90 dias, os dentes foram extraídos, fixados em formalina e preparados para análise imunoistoquímica. Os agentes hemostáticos não influenciaram a expressão de TN e FN. Ambas glicoproteínas foram encontradas em todo tecido pulpar, ao redor das fibras colágenas e estiveram ausentes nos tecidos mineralizados. Na pré-dentina, a TN mostrou forte imunoexpressão e a FN teve uma expressão variável. Após 7 dias, foi observada uma expressão levemente mais pronunciada no lugar da exposição pulpar. Aos 30 dias, a TN e a FN demonstraram uma expressão mais forte sob a barreira dentinária e aos 90 dias, uma expressão fina e linear da TN e FN apresentava-se delimitando a dentina reparativa. Em conclusão, os agentes hemostáticos não influenciaram e expressão da TN e da FN. A imunoexpressão da TN e FN foi observada em diferentes regiões e períodos, demonstrando o seu papel no reparo pulpar.

Effects of the medicinal plants Curcuma zedoaria and Camellia sinensis on halitosis control

Volatile sulphur compounds (VSC) are the gases mainly responsible for halitosis (bad breath). The aim of this research was to evaluate the effects of medicinal plants on halitosis control. Two commonly used plants were tested: Curcuma zedoaria and Camellia sinensis (green tea). These plants were prepared as an aqueous solution and used as mouthwashes, compared with a standard mouthwash of 0.12% chlorhexidine gluconate and a placebo (water). The experiment was conducted with 30 volunteers from the School of Dentistry of São Jose dos Campos, Univ. Estadual Paulista - UNESP, SP, Brazil. Each volunteer tested the four mouthwashes. The Cysteine Challenge Method, modified for this study, was used for initial breath standardization. Four breath assessments were conducted after volunteers rinsed orally with acetylcysteine: one before the test mouthwash was used; the second, one minute after its use; a third 90 minutes later; and the last 180 minutes later. The results showed that chlorhexidine gluconate lowered VSC production immediately, and that this effect lasted up to 3 hours, while the tested plants had immediate inhibitory effects but no residual inhibitory effects on VSC. We concluded that Curcuma zedoaria and Camellia sinensis, prepared as infusions and used as mouthwashes, did not have a residual neutralizing effect on VSC.