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.

Antibiofilm and Antibacterial Activities of Farnesol and Xylitol as Potential Endodontic Irrigants

This study investigated the antibiofilm and antibacterial effects of farnesol and xylitol in a series of experiments in order to evaluate their potential use as root canal irrigants. The following substances were tested: 0.2% farnesol; 5% and 20% xylitol; 0.2% farnesol plus 20% xylitol; and saline (control). For comparison with an established endodontic irrigant, 2.5% NaOCl was included in each test. Three experiments were conducted: the crystal violet assay, to evaluate the effects on the biofilm biomass; the dentin disinfection test, to evaluate the effects on bacterial viability in biofilms; and the root canal disinfection test, to simulate the use in the root canal environment. Farnesol was the most effective substance in reducing the biofilm biomass, followed by 20% xylitol. All substances affected bacterial viability in biofilms; farnesol showed the best results followed by the farnesol/xylitol combination. Irrigation with all substances significantly reduced the bacterial load (p<0.001), but only the farnesol/xylitol combination was significantly more effective than saline (p=0.02). NaOCl was more effective than any other substance tested in the three experiments (p<0.001). The findings demonstrated that farnesol affected both the biofilm biomass and the viability of cells in the biofilm, while 20% xylitol affected only the biofilm biomass. Although not more effective than NaOCl, the combination of these two antibiofilm substances has potential to be used in endodontics in certain situations.

Este estudo investigou os efeitos antibiofilme e antibacteriano de farnesol e xilitol em uma série de experimentos para avaliar seu uso potencial como irrigante de canais radiculares. As seguintes substâncias foram testadas: farnesol a 0,2%; xilitol a 5% e 20%; farnesol a 0,2% combinado com xilitol a 20%; e solução salina (controle). NaOCl foi testado para comparação. Três experimentos foram conduzidos: o teste do cristal violeta para avaliar os efeitos sobre a biomassa de biofilme, o teste da desinfecção de fragmentos de dentina para avaliar os efeitos na viabilidade bacteriana nos biofilmes e o teste da desinfecção de canal radicular para simular o uso no ambiente do canal radicular. Farnesol foi o mais eficaz, seguido por xylitol a 20%. Todas as substâncias afetaram a viabilidade bacteriana nos biofilmes; farnesol mostrou os melhores resultados, seguido pela combinação farnesol/xilitol. A irrigação com todas as substâncias reduziu significativamente a carga bacteriana (p<0,001), mas somente a combinação farnesol/xilitol foi significativamente mais eficaz que a solução salina (p=0,02). NaOCl foi mais eficaz que qualquer outra substância testada nos três experimentos (p<0,001). Os achados demonstraram que farnesol afetou tanto a biomassa de biofilme quanto a viabilidade das células no biofilme, enquanto que xilitol a 20% afetou a biomassa de biofilme. Embora não mais eficazes que NaOCl, combinações dessas duas substâncias antibiofilmes têm o potencial de ser usadas na Endodontia, em determinadas situações.

Effect of repeated immersion solution cycles on the color stability of denture tooth acrylic resins

OBJECTIVE: Chemical solutions have been widely used for disinfection of dentures, but their effect on color stability of denture tooth acrylic resins after repeated procedures is still unclear. The aim of this in vitro study was to evaluate whether repeated cycles of chemical disinfectants affected the color stability of two denture tooth acrylic resins. MATERIAL AND METHODS: Sixty disc-shaped specimens (40 mm x 3 mm) were fabricated from two different brands (Artiplus and Trilux) of denture tooth acrylic resin. The specimens from each brand (n=30) were randomly divided into 6 groups (n=5) and immersed in the following solutions: distilled water (control group) and 5 disinfecting solutions (1 percent sodium hypochlorite, 2 percent sodium hypochlorite, 5.25 percent sodium hypochlorite, 2 percent glutaraldehyde, and 4 percent chlorhexidine gluconate). Tooth color measurements were made by spectrophotometry. Before disinfection, the initial color of each tooth was recorded. Further color measurements were determined after subjecting the specimens to 7, 21, 30, 45, 60, and 90 immersion cycles in each tested solution. Color differences (ΔE*) were determined using the CIE L*a*b* color system. Data were analyzed using two-way repeated measures analysis of variance (ANOVA) followed by Tukey tests. The significance level was set at 5 percent. RESULTS: There were statistically significant differences in ΔE* among the 5 disinfectants and water during the 90 cycles of immersion for both denture tooth acrylic resins. Distilled water promoted the greatest color change in both denture tooth acrylic resins, nevertheless none of tested disinfectants promoted ΔE* values higher than 1.0 on these acrylic materials during the 90 cycles of disinfection. CONCLUSIONS: Repeated immersion cycles in disinfecting solutions alter ΔE* values, however these values do not compromise the color of the tested denture tooth acrylic resins because they are imperceptible to the human eye.

Saliva and tongue coating pH before and after use of mouthwashes and relationship with parameters of halitosis

OBJECTIVES: The aim of this work was to evaluate saliva and tongue coating pH in oral healthy patients with morning bad breath before and after use of different oral mouthrinses. MATERIAL AND METHODS: Saliva and tongue coating pH of 50 patients allocated in 5 groups were measured respectively by a digital pHmeter and color pH indicators, before, immediately after and 30 min after rinsing 5 different mouthrinses: cetilpiridine chloride associated with sodium chloride, triclosan, enzymatic solution, essential oil and distilled water. RESULTS: Only triclosan and essential oil increased salivary pH immediately after rising. The enzymatic solution decreased salivary and tongue coating pH immediately after rinsing. CONCLUSIONS: Salivary pH tended to be acidic while tongue coating pH tended to be alkaline, even after rising. Triclosan and essential oil mouthrinses increased salivary pH immediately after rinsing. Enzymatic solution decreased saliva and tongue coating pH immediately after rising.

Effect of inmersion desinfection with 0, 5 percent sodium hypochlorite and 2 percent glutaraldehyde on alginate and silicone: microbiology and SEM study / Efecto de la desinfección en inmersión con 0, 5 por ciento de hipoclorito sódico y glutaraldehído al 2 por ciento sobre alginato y silicona: estudio de la microbiología y SEM

The disinfection of dental impression materials has become an essential topic of universal concern, as it may be the first instance of microbial contamination during dental care. The purpose of this study is twofold: To determine the effectiveness of disinfection with 0.5 percent sodium hypochlorite and 2 percent glutaraldehyde solutions in irreversible hydrocolloid (alginate) and silicone impressions and to analyze the effect of disinfection on surface quality with a scanning electronic microscope. Atotal of 32 impressions (16 made of irreversible hydrocolloid and 16 made of silicone) were taken from maxillary dentate patients. Samples of 1cm2 (80 , irreversible hydrocolloid, 80 silicone) were obtained and distributed in ten groups: alginate in no disinfectant (control group 1, AL), alginate in 0.5 percent sodium hypochlorite (NaOCl) for 5 (AH5) and 10 minutes (AH10), alginate in 2 percent glutaraldehyde for 5 (AG5) and 10 minutes (AG10), silicone in no disinfectant (control group 2), silicone in 0.5 percent NaOCl for5 (SH5) and 10 minutes (SH10), and silicone in 2 percent glutaraldehyde for 5 (SG5) and 10 minutes (SG10). Each sample was divided into two segments (one for the microbiological and one for the SEM study). Microbiological samples were planted on blood agar, Mac Conkey agar, and Sabouraud agar, and identification was made by Gram´s stain. The samples were then processed by an SEM. Immersion in the 5 percent NaOCl and 2 percent glutaraldehyde for 10 minutes completely eliminated bacteria in the impressions, compared with the control group (P=0.000004). Immersion in 0.5 percent NaOCl and 2 percent glutaraldehyde for 5 and 10 minutes significantly inhibited bacterial growth in both the irreversible hydrocolloid and silicone impressions compared with control group (P<0.05). However, in the SEM study, immersion in both disinfectant solutions for 5 and 10 minutes did not significantly affect the surface quality of the irreversible hydrocolloid...

La desinfección de los materiales de impresión dental se ha convertido en un tema esencial, ya que puede ser el primer caso de contaminación microbiana durante la atención dental. El propósito de este estudio es doble: determinar la eficacia de la desinfección con hipoclorito sódico al 0,5 por ciento y 2 por ciento de glutaraldehído en soluciones de hidrocoloide irreversible (alginato) y las impresiones de silicona, para analizar el efecto de la desinfección en la calidad de la superficie con un microscopio electrónico de barrido. Un total de 32 impresiones (16 hechas de hidrocoloides irreversibles y 16 de silicona) superiores de pacientes dentados fueron estudiadas. Las muestras de 1cm2 (80, hidrocoloide irreversible, el 80 de silicona) fueron obtenidas y distribuidas en diez grupos: alginato sin desinfectante (grupo de control1, AL), alginato en el 0,5 por ciento de hipoclorito sódico (NaOCl) durante 5 (AH5) y 10 minutos (AH10), alginato en glutaraldehído al 2 por ciento durante 5 (GA5) y 10 minutos (AG10), silicona sin desinfectante (grupo de control 2), silicona en 0,5 por ciento de NaOCldurante 5 (SH5) y 10 minutos (SH10) y, en glutaraldehído al 2 por ciento durante 5 (SG5) y 10 minutos (SG10). Cada muestra se dividió en dos segmentos (uno para los análisis microbiológicos y uno para el estudio SEM). Las muestras microbiológicasse sembraron en agar sangre, agar MacConkey y agar Sabouraud, y la identificación se realizó por tinción de Gram. Las muestras fueron procesadas por un SEM. La inmersión en 5 por ciento NaOCl y 2 por ciento de glutaraldehído durante 10 minutos eliminó completamente las bacterias de las impresiones, en comparación con el grupo control (P = 0,000004). La inmersión en 0,5 por ciento de NaOCl y glutaraldehído al 2 por ciento durante 5 y 10 minutos, inhibió el crecimiento de bacterias, tanto en el hidrocoloide irreversible e impresiones de silicona en comparación con el grupo control (P <0,05). Sin embargo, en el estudio SEM...

Effect of sodium bicarbonate on Candida albicans adherence to thermally activated acrylic resin

The purpose of this study was to evaluate the effect of 5 percent sodium bicarbonate on the adherence of Candida albicans to thermally activated acrylic resin. Fifty 4 mm² specimens of acrylic resin were obtained using a metallic matrix. The specimens received chemical polishing, were sterilized and then immersed in Sabouraud broth, inoculated with Candida albicans standardized suspension. After 24 hours of incubation at 37ºC, the specimens were divided into four groups according to the substance used for disinfection (5 percent sodium bicarbonate, 0.12 percent digluconate chlorhexidine, vinegar and Corega Tabs). A control group was included, in which distilled water was used. The adhered microorganisms were dispersed, diluted and plated onto culture media to determine the number of colony-forming units (cfu/mL). The results were analyzed through the Mann-Whitney statistical test at the 5 percent level of significance. Only 0.12 percent digluconate chlorhexidine and 5 percent sodium bicarbonate presented a statistically significant difference (p = 0.0010 and p = 0.0156, respectively) compared to the control group, decreasing the number of cfu/mL. However, when the different disinfecting solutions were compared with each other, only 0.12 percent digluconate chlorhexidine presented a statistically significant difference in the reduction of cfu/mL. It was concluded that although 0.12 percent digluconate chlorhexidine was more effective in the reduction of Candida albicans adherence values to thermally activated acrylic resin, 5 percent sodium bicarbonate also proved to be a viable alternative.

In vitro antifungal action of different substances over microwaved-cured acrylic resins

OBJECTIVE: The presence of Candida albicans on the surfaces of denture-base acrylic resins is strongly related to the development of oral stomatitis. This study evaluated the antifungal action of different agents over microwave-cured acrylic resin without polishing specimens previously contaminated with Candida albicans. MATERIAL AND METHODS: Sixty specimens were immersed in BHI broth previously inoculated with the yeast and stored for 3 h at 37ºC. They were divided into 5 experimental groups (n=10): G1: 2 percent chlorhexidine solution (10 min); G2: 0.5 percent sodium hypochlorite (10 min); G3: modified sodium hypochlorite (10 min); G4: effervescent agent (5 min); G5: hydrogen peroxide 10v (30 min). The specimens of the control group 1 (C1) were not disinfected. Ten additional specimens of the control group 2 (C2) were not infected with the yeast, aiming to check the asepsis during the experiment. The disinfection agents were neutralized and the acrylic resin specimens were immersed in BHI Broth for 24 h. Culture media turbidity was evaluated spectrophotometrically according to the transmittance degree, i.e. the higher the transmittance the stronger the antimicrobial action. Statistical analysis was performed (Kruskal-Wallis Test, p<0.05). RESULTS: The results, represented by the medians, were: G1 = 40; G2 = 100; G3 = 100; G4 = 90; G5 = 100; C1 = 40; C2 = 100. CONCLUSIONS: This in vitro study suggested that sodium hypochlorite-based substances and hydrogen peroxide are more efficient disinfectants against C. albicans than 2 percent chlorhexidine solution and the effervescent agent.

Comparative study of the antimicrobial efficacy of chlorhexidine gel, chlorhexidine solution and sodium hypochlorite as endodontic irrigants

The purpose of this study was to assess the in vitro the antimicrobial efficacy of chlorhexidine gluconate gel as an endodontic auxiliary chemical substance compared to sodium hypochlorite (NaOCl) and chlorhexidine gluconate solution. The antimicrobial efficacy of the tested substances was evaluated using the agar diffusion test. The growth inhibition zones produced by 0.2 percent, 1 percent and 2 percent chlorhexidine gel were evaluated against 5 facultative anaerobic bacteria and 4 pigmented Gram-negative anaerobes, and compared to the results obtained by NaOCl and chlorhexidine solution. The largest growth inhibition zones were produced when the test bacteria were in contact with 2 percent chlorhexidine gluconate gel (11.79 mm), being significantly different (p<0.05) from the growth inhibition zones produced by all NaOClconcentrations, including 5.25 percent (9.54 mm). However, there was no statistically significant difference (p>0.05) between the growth inhibition zones obtained with equal concentrations of chlorhexidine solution and gel. The results of this study indicate that, as far as its antimicrobial properties are concerned, chlorhexidine gel has a great potential to be used as an endodontic auxiliary chemical substance.

O objetivo deste estudo foi avaliar in vitro a atividade antimicrobiana do gluconato de clorexidina gel, como irrigante endodôntico, comparando-o ao hipoclorito de sódio (NaOCl) e ao gluconato de clorexidina líquido. A atividade antimicrobiana das substâncias testadas foi avaliada pelo teste de difusão em ágar. As zonas de inibição de crescimento bacteriano produzidas pela clorexidina gel a 0,2 por cento; 1 por cento e 2 por cento foram observados frente a 5 espécies de bactérias anaeróbias facultativas e 4 espécies de anaeróbios estritos, Gram-negativos e produtores de pigmento negro; e comparados com os resultados obtidos pelo NaOCl e pela clorexidina líquida. As maiores zonas de inibição foram produzidas quando as bactérias testadas ficaram em contato com a clorexidina a 2 por cento em gel (11,79 mm), apresentando diferença estatisticamente significante (p<0,05) quando comparados às zonas de inibição de crescimento bacteriano produzidas por todas as concentrações avaliadas de NaOCl, incluindo 5,25 por cento (9,54 mm). No entanto, não houve diferença estatisticamente significante (p>0,05) comparando as zonas produzidas por concentrações equivalentes de clorexidina líquida ou gel. Os resultados indicaram que a clorexidina em gel tem grande potencial para ser usada como substância química auxiliar quanto às suas propriedades antimicrobianas.

The effect of 0.5% sodium hypochlorite and 2% glutaraldehyde spray disenfectants on irreversible hydrocolloid impression material.

Infection control has assumed prime importance in dentistry. It is a prime concern in prosthodontics as well, where impressions materials are most commonly used. Impression materials can act as a medium for cross infection. To prevent cross infection many products are being developed. Among them 0.5% Sodium hypochlorite and 2% Glutaraldehyde are considered effective. This study was done to asses the efficacy of 0.5% Sodium hypochlorite and 2% Glutaraldehyde on irreversible hydrocolloid impression material. The result of the study indicated that they are effective against both Gram positive and Gram negative organisms and their use is recommended.

Microbial contamination of tooth brushes and their decontamination.

With the dawn of the new century, dentistry has seen a new face in the fields of diagnosis, treatment and prevention. Twenty one children were asked to brush their teeth for five days. The brushes were put in Robertson's Cooked Meat broth and cultured. Growth of Streptococcus Mutans were seen. These brushes were then placed in disinfectants such as 0.2% chlorhexidine gluconate (Gp I), 1% sodium hypochlorite(Gp II) and water (Gp III) for 24 hrs and then cultured. Disappearance of growth of microorganisms was seen in Gp I and Gp II and remnants of growth seen in Gp III. It can be concluded that the use of disinfectant is a must for every individual at regular intervals.

Contamination of toothbrush at different time intervals and effectiveness of various disinfecting solutions in reducing the contamination of toothbrush.

The common devices used for oral hygiene measures are toothbrush, dentifrice and oral rinses. Present study was carried out to know the level of contamination of toothbrush after brushing and at the same time, to know the efficacy of various disinfecting solution in reducing their contamination. Thirty two children in the age group of 12-14, residing in Government Hostel were selected. They were divided into four groups of 8 each, and were supplied with toothbrushes. Toothbrushes were cultured to assess the contamination at different time intervals. Control group had shown the highest percentage of contamination. It was concluded that cleaning of the oral cavity is not the only procedure in maintaining the oral hygiene, the oral hygiene devices should also be kept clean.

Avaliaçäo microbiológica de soluçöes desinfetantes e barreiras protetoras, usadas como meio de controle de infecçäo nos procedimentos radiográficos em Odontologia / Microbiologic study of desinfectant solutions and protector barriers, used for infection control in the radiographic procedures in Dentistry

Essa pesquisa teve como objetivo avaliar, através de testes microbiológicos, a efetividade de soluçöes desinfetantes e barreiras mecânicas usadas para controle de infecçäo durante os procedimentos radiográficos em Odontologia. As soluçöes testadas foram: álcool 70 por cento (p/v); hipoclorito de sódio 1 por cento - liquido de Milton; Germpol Plus - fenóis, as quais foram friccionadas com gazes estéreis durante 30 segundos em ambos os lados dos filmes radiográficos intrabucais Kodak EP-21P e Agfa Dentus M2 Comfort. As barreiras usadas foram: filme de polietileno - LAFRApack; filme de PVC - FACILpack; e sacos plásticos transparentes, pequenos, vendidos a granel. Para os testes microbiológicos foram usados vários meios de cultura, incubaçäo em aerobiose e anaerobiose, e bactérias do tipo Streptococcus mutans, Staphylococcus aureus, Bacillus subtilis e Escherichia coli. Também foi realizado teste com microorganismo menor que as bactérias acima relacionadas, sendo utilizados bacteriófagos (fagos), que têm entre 50 e 70 mm. Com esses vírus de bactéria, testaram-se somente as barreiras...

A study of toothbrush contamination at different time intervals and comparative effectiveness of various disinfecting solutions in reducing toothbrush contamination.

Toothbrush contamination during the procedure of brushing was assessed at different time intervals of usage. A peak value of 100% contamination was found at 1 month interval. Hence, a method suggesting disinfection of the toothbrush was employed by comparing the effectiveness of various disinfecting solutions available in the market so that, the brush does not become a source of potential pathogens.