Physicochemical and microbiological assessment of a dental adhesive doped with cashew nut shell liquid.

To evaluate i) the inhibitory and bactericidal activity of cashew nut shell liquid (CNSL) and its isolated compounds (anacardic acid and cardol) against oral bacteria; ii) the biofilm formation inhibition, resin-dentin bond strength and physicochemical properties of a dental adhesive incorporated with these substances. The antibacterial effect of CNSL, anacardic acid, and cardol were assessed by determining the minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations. Effect in inhibiting biofilm formation of the adhesive incorporated with the substances (15 µg/ml) against a mixed-species biofilm of Streptococcus mutans and Candida Albicans and was determined by direct contact test. Additional Analysis included microtensile bond strength (µTBS) test, elastic modulus (EM), flexural strength (FS), degree of conversion (DC), water sorption (WS) and solubility (SL). The data were submitted to statistical analysis by one-way ANOVA and Tukey's test (p < 0.05). CNSL, anacardic acid and cardol showed antibacterial activity for all strains tested, with MIC and MBC values ranging from 3.12 to 25 µg/ml. There was no growth of colonies forming units in the adhesives incorporated with the substances. EM increased in the adhesive incorporated with anacardic acid, decreased after incorporation of cardol and it was not affected by incorporation of CNSL. The substances tested showed no effect in FS, DC, WS, SL and µTBS. In conclusion, the CNSL, anacardic acid and cardol showed antibacterial effects against oral bacteria and, the incorporation of substances did not reduce the performance of the adhesive.

Antibacterial activity of salvia officinalis L. against periodontopathogens: An in vitro study.

Being aware of the remarkable antimicrobial potential of S. officinalis L., we aimed to evaluate the antimicrobial activity of the S. officinalis dichloromethane crude extract (SOD), dichloromethane-soluble fractions (SODH and SODD), SODD subfractions (SODD1 and SODD2), and pure substances (manool, salvigenin, and viridiflorol) against periodontopathogens. This bioassay-guided study comprises five antimicrobial tests-determination of the Minimum Inhibitory Concentration (MIC), determination of the Minimum Bactericidal Concentration (MBC), determination of the antibiofilm activity, construction of the Time-kill curve (determination of Bactericidal Kinetics), and determination of the Fractional Inhibitory Concentration Index-on six clinical bacterial isolates and three standard bacterial strains involved in periodontal disease. SOD has moderate activity against most of the tested bacteria, whereas SODD1, SODH1, SODH3, and manool afford the lowest results. The Porphyromonas gingivalis (ATTC and clinical isolate) biofilm is considerably resistant to all the samples. In association with chlorhexidine gluconate, only SODH1 exerts additive action against P. gingivalis (clinical isolate). Therefore, SODH1 and manool are promising antibacterial agents and may provide therapeutic solutions for periodontal infections.

Effect of the aging of titanium and zirconia abutment surfaces on the viability, adhesion, and proliferation of cells and the adhesion of microorganisms.

STATEMENT OF PROBLEM: The longevity of dental implants depends on the maintenance of peri-implant tissue and absence of inflammation. How the physical-chemical properties intrinsic to each material over time can affect adhesion, given constant cell turnover and biofilm development, remains unclear. PURPOSE: The purpose of this in vitro study was to evaluate the influence of aging on the viability, adhesion, and proliferation of normal oral keratinocytes (Nok-si) and on the multispecies biofilm formation of Fusobacterium nucleatum (F. nucleatum), Porphyromonas gingivalis (P. gingivalis), and Streptococcus sanguinis (S. sanguinis). MATERIAL AND METHODS: Zirconia (ZrO2) and titanium (Ti) disks were analyzed by surface roughness, water contact angle, and X-ray diffraction before and after aging in an autoclave. The Nok-si cell viability was evaluated by using a 3-(4.5-dimethylthiazole-2-yl)2.5-diphenyl tetrazolium bromide assay (MTT), morphology by scanning electron microscopy (SEM), and proliferation and adhesion by using a confocal microscope. Multispecies biofilms were analyzed quantitatively by colony-forming units per milliliter (CFU/mL) and qualitatively by SEM. RESULTS: For Ti, the aging process affected the roughness and wettability. However, for ZrO2, the aging did not affect roughness but did affect wettability and the ratio of the tetragonal to monoclinic phase (P<.05). A significant difference was found in the bacterial growth for Ti (nonaged and aged) in relation to the control, and no differences were found in Ti before and after aging; however, ZrO2 had increased growth of microorganisms after aging. For ZrO2, a statistically significant difference was found between aged ZrO2 and the control (P<.001). CONCLUSIONS: The results indicate that, after the aging, Ti showed better cell adhesion and proliferation and lower biofilm adhesion than zirconia.

Laryngeal Cancer Attributable Factors and the Influence on Survival Rates: A Single Brazilian Institution Experience

Abstract Introduction Epidemiological studies focused on prognostic factors associated with laryngeal cancer in the Brazilian population are poorly reported in the literature. Objective To evaluate the influence of certain risk factors on the survival rates of patients with squamous cell carcinoma (SCC) of the larynx. Methods This retrospective study was conducted on adult patients who were admitted to the outpatient clinic of the head and neck department in a tertiary care hospital. Evaluation of the influence of risk factors on the survival rates of patients registered in the hospital with laryngeal SCC was performed based on age, sex, initial stage, time of evolution, habits, educational levels and relapse and death. Overall survival (OS), disease-free survival (DFS) and clinical-demographic data were analyzed using the Kaplan-Meier method, Log-rank test and Cox regression. Results A total of 107 patients with a mean age of 59.8 years (range 19-81) were included in this study. Stages III and IV were associated with decreased DFS (p = 0.02) and OS (p = 0.02). Smoking patients had a greater period of disease evolution than non-smoking patients (p = 0.003). Alcohol consumption in smokers increased the risk of death by 2.8 (p = 0.002) compared with non-drinking smokers. Male patients presented lower DFS average when compared with female patients (p = 0.04). Conclusion Our study confirms that male gender, smoking habit combined with alcohol consumption, and advanced stages were strongly associated with poor prognosis.

Laryngeal Cancer Attributable Factors and the Influence on Survival Rates: A Single Brazilian Institution Experience.

Introduction Epidemiological studies focused on prognostic factors associated with laryngeal cancer in the Brazilian population are poorly reported in the literature. Objective To evaluate the influence of certain risk factors on the survival rates of patients with squamous cell carcinoma (SCC) of the larynx. Methods This retrospective study was conducted on adult patients who were admitted to the outpatient clinic of the head and neck department in a tertiary care hospital. Evaluation of the influence of risk factors on the survival rates of patients registered in the hospital with laryngeal SCC was performed based on age, sex, initial stage, time of evolution, habits, educational levels and relapse and death. Overall survival (OS), disease-free survival (DFS) and clinical-demographic data were analyzed using the Kaplan-Meier method, Log-rank test and Cox regression. Results A total of 107 patients with a mean age of 59.8 years (range 19-81) were included in this study. Stages III and IV were associated with decreased DFS ( p = 0.02) and OS ( p = 0.02). Smoking patients had a greater period of disease evolution than non-smoking patients ( p = 0.003). Alcohol consumption in smokers increased the risk of death by 2.8 ( p = 0.002) compared with non-drinking smokers. Male patients presented lower DFS average when compared with female patients ( p = 0.04). Conclusion Our study confirms that male gender, smoking habit combined with alcohol consumption, and advanced stages were strongly associated with poor prognosis.

Susceptibility to Oral Antiseptics and Virulence Factors Ex Vivo Associated with Candida spp. Isolated from Dental Prostheses.

PURPOSE: To isolate Candida spp. from dental prosthesis users' saliva and to evaluate the isolates for the presence of several virulence factors. This research also aimed to investigate the antifungal activity of 3 commercial mouthwashes/oral antiseptic formulations containing 0.12% chlorhexidine, 0.07% cetylpyridinium, or 0.075% cetylpyridinium against planktonic and sessile (biofilm mode) yeast cells. MATERIALS AND METHODS: Forty-three Candida yeasts were isolated from 32 of 70 selected patients, and the virulence factors of C. albicans, C. krusei, C. glabrata, C. tropicalis, and C. parapsilosis species were investigated by polymerase chain reaction (PCR) and proteinase in plates. Minimum inhibitory concentration (MIC), and in vitro biofilm assay evaluated the antifungal activity of antiseptics. RESULTS: C. albicans, C. krusei, C. glabrata, C. tropicalis, and C. parapsilosis were detected in mono and mixed cultures. Only C. albicans displayed genes related to adhesion and proteinases (ALS2, ALS3, SAP1, and SAP3). The aspartate proteinase activity was found in 60.46% of isolates. The tested antiseptic formulations exhibited a MIC less than 1.25% toward yeasts in the planktonic mode. According to XTT ((2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) assay results, most Candida isolates and all mixed cultures formed biofilms within 24 hours. The evaluated antiseptic formulations were also active against biofilms. CONCLUSION: Most virulence factors investigated here (ALS2, ALS3, SAP1, and SAP3) occurred in the majority of the Candida spp. isolates, especially in C. albicans. The tested mouthwash formulations were effective against all the yeast isolates in both the planktonic and sessile growth modes. Developing alternative therapies that can avoid or control biofilm formation is necessary to prevent oral candidiasis and other Candida spp. infections.

Risk of Fungal Infection to Dental Patients.

Fungi can cause various diseases, and some pathogenic fungi have been detected in the water of dental equipment. This environment offers suitable conditions for fungal biofilms to emerge, which can facilitate mycological contamination. This study verified whether the water employed in the dental units of two dental clinics at the University of Franca was contaminated with fungi. This study also evaluated the ability of the detected fungi to form biofilms. The high-revving engine contained the largest average amount of fungi, 14.93 ± 18.18 CFU/mL. The main fungal species verified in this equipment belonged to the genera Aspergillus spp., Fusarium spp., Candida spp., and Rhodotorula spp. Among the isolated filamentous fungi, only one fungus of the genus Fusarium spp. did not form biofilms. As for yeasts, all the Candida spp. isolates grew as biofilm, but none of the Rhodotorula spp. isolates demonstrated this ability. Given that professionals and patients are often exposed to water and aerosols generated by the dental procedure, the several fungal species detected herein represent a potential risk especially to immunocompromised patients undergoing dental treatment. Therefore, frequent microbiological monitoring of the water employed in dental equipment is crucial to reduce the presence of contaminants.

Endodontics pastes formulated with copaiba oil: action on oral microbiota and dentin bridge formation in dogs / Pastas endodônticas formuladas com óleo de copaíba: ação na microbiota bucal e formação de ponte dentinária em cães

This study analysed the effect of pastes formulated with calcium hydroxide P.A. and different vehicles (saline solution - paste A and Copaifera langsdorffii Desfon oil - paste B) on oral microorganisms and dentin bridge formation in dogs. The antimicrobial action of the pastes and their components was analysed by the minimum inhibitory concentration in agar gel technique. The components were diluted and tested on fifteen standard strains of microorganisms associated with endodontic diseases. The microorganisms were cultivated and after incubation data was analysed using One-Way ANOVA and Turkey's test (P≤0.05). Four superior incisors of ten animals were used to evaluate dentin bridge formation. Two incisors were capped with paste A (GA) and two with paste B (GB). After 90 days, the teeth were extracted for histological analysis and the degree of dentin bridge formation evaluated. Data was analysed by the Kruskal-Wallis test (P<0.05). The pastes and their components were classified in the following decreasing order of antimicrobial action: calcium hydroxide P.A., paste A, paste B and Copaifera langsdorffii Desfon oil. Calcium hydroxide P.A. showed significantly higher antimicrobial action than the pastes or their vehicles. No significant difference was observed between the two pastes in dentin bridge formation. Based on the microorganisms studied, it can be concluded that the pastes analysed showed similar antimicrobial potential but differed significantly from their individual components. No significant difference was observed in dentin bridge formation between the different pastes tested.

Foi avaliada a ação de pastas formuladas com hidróxido de cálcio P.A. e diferentes veículos (solução fisiológica - pasta A e óleo de Copaifera langsdorffii Desfon - pasta B) sobre microrganismos bucais e formação de ponte dentinária em cães. A ação antimicrobiana das pastas e de seus componentes individuais foi avaliada pela técnica da concentração inibitória mínima pela diluição em ágar. Os materiais foram diluídos e avaliados contra quinze cepas padrão de microrganismos relacionados a doenças endodônticas. Os microrganismos foram cultivados e, após a incubação, os dados foram analisados (Anova One-Way, Tukey, P≤0,05). Para a avaliação da formação de ponte dentinária, quatro incisivos superiores de dez animais foram tratados, sendo dois capeados com pasta A (GA) e dois com a pasta B (GB). Após 90 dias, os dentes foram extraídos para obtenção de cortes histológicos, com o objetivo de se avaliar o grau de formação de ponte dentinária. Os dados obtidos foram submetidos à análise estatística (Kruskal-Wallis, P<0,05). Segundo a ação antimicrobiana, os materiais foram classificados em ordem decrescente: hidróxido de cálcio P.A., pasta A, pasta B e óleo de Copaifera langsdorffii Desfon, com diferenças estatisticamente significantes entre o hidróxido de cálcio P.A., as pastas e os veículos. Ao final do estudo, observou-se que as duas pastas avaliadas foram semelhantes quanto à formação de ponte dentinária. Considerando-se os microrganismos selecionados, conclui-se que as pastas avaliadas foram semelhantes entre si em termos de potencial antimicrobiano, diferindo dos componentes individuais. Em relação à formação de ponte dentinária, não foram observadas diferenças significantes entre os dentes tratados com as diferentes pastas.

Influencia de los tipos de anclaje de los filamentos en la retención de streptococcus mutans en cepillos dentales: estudio preliminar / Influence of the types of filaments anchoring in the retention of streptococcus mutans on toothbrushes: preliminary study

Este estudio evaluó la retención del S. mutans (ATCC 25175) en los cepillos dentales Oral B Complete® y Sensodyne Esmalte Care®, que poseen distintas características de fijación y anclaje de los filamentos en sus partes activas. Nueve cepillos dentales de cada marca comercial fueron esterilizados en autoclave y, a continuación, inoculados con S. mutans (ATCC 25175), previamente desarrollado en caldo Brain Heart Infusion (BHI). Los análisis de retención bacteriana se realizaron en los tempos de 04, 12 y 24 horas de incubación, a 37ºC y en microaerofilia, en triplicata. En esas etapas, los cepillos fueron lavados con agua esterilizada e introducidos en tubos Falcon con caldo BHI, del cual fueron preparadas diluciones decimales hasta 10-3 para las cuatro primeras horas, hasta 10-4 para 12 horas, y hasta 10-5 para 24 horas de incubación. Alícuotas de esas diluciones fueron sembradas en la superficie del Ágar BHI, siendo las placas incubadas en microaerofilia por 24h a 37ºC. Tras la incubación, fue realizado un recuento de las unidades formadoras de colonia por mL (UFC/mL) y el análisis estadístico (Tests de Tukey pareado, p?0,05). Fueron observadas diferencias estadísticamente significantes (p?0,05) entre lo tiempos de evaluación de 12 horas. Concluyese que el cepillo dental Oral B Complete® presentó, comparativamente a Sensodyne Esmalte Care®, mayor retención del S. mutans (ATCC 25175).

This work evaluated the retention of S. mutans ATCC 25175 in the Oral B Complete and Sensodyne Esmalte Care toothbrushes that have distinct characteristics of insertion and anchorage of the filaments in its active parts. Nine toothbrushes of each trademark were sterilized in autoclave and, following this procedure, inoculated with S. mutans ATCC 25175, previously developed in Brain Heart Infusion (BHI).The analyses of bacterial retention occurred in the times of 04, 12 and 24 hours after incubation, at 37ºC and in microaerophilic, in triplicate. In these stages, the toothbrushes were washed with sterilized water and enclosed in Falcon tubes with BHI broth, of which decimal dilutions up to 10-3 were made for the four first hours, up to 10-4 for 12 hours, and up to 10-5 for 24 hours of incubation. Aliquots of these dilutions were sown in the surface of agar BHI, and the Petri dishes were incubated in microaerophilic for 24 hours, in a temperature of 37ºC. After the incubation, the counting of the colony forming units and the statistical analysis (Tukey Test paired, p?0.05) were performed. Significant statistical differences were observed (p?0.05) between the times of evaluation of 12 hours. It was concluded that the Oral B Complete toothbrush presents, compared with Sensodyne Esmalte Care, greater retention of S. mutans ATCC 25175.

Uso da nanocobertura de prata (B-Safe) para controlar a contaminação na prática da prótese sobreimplantes: avaliação clínica quantitativa com dois anos de acompanhamento / Use of a silver nanocoating technology (B-Safe) to control contamination on the practice of implant-supported prostheses: a 2-year follow-up quantitative clinical evaluation

Objetivos: este trabalho avaliou a adesão de microrganismos em mangueiras com nanotecnologia de prata para prevenção da contaminação em procedimentos aplicáveis à prótese sobreimplantes. Material e métodos: após 24 meses de uso clínico, 20 segmentos de mangueiras foram divididos em dois grupos iguais (com e sem B-Safe, dez elementos cada) e colocados em tubos de ensaio contendo 10 mL de caldo BHI, incubados a 37ºC em condições de aerobiose. Depois, foram realizadas diluições decimais seriadas de alíquotas de 50,0 µL em dois meios de cultura: ágar sangue e ágar-sabourad dextrose, bem como a incubação das placas de Petri a 37ºC por 24/48h em aerobiose. Diferenças nas contagens de microrganismos (UFC/mL) foram analisadas pelos testes Anova e Tukey (p ≤ 0,05). Resultados: houve turvação do meio de cultura em todos os tubos do grupo controle, sendo que a contagem das colônias formadas revelou um alto nível de contaminação em mangueiras convencionais (ágar-sangue: 2.025 UFC/mL e agar-dextrose: 483 UFC/mL). Os tubos do grupo controle não apresentaram turvação, tampouco unidades formadoras de colônias. Conclusão: a tecnologia da nanocobertura de prata incorporada à linha de água do consultório pode impedir a contaminação durante os procedimentos clínicos para confecção das próteses sobreimplantes.

Objectives: this study evaluated the adherence of microorganisms to tubes with silver nanotechnology to prevent contamination in implant-supported associated procedures. Material and methods: after 24 months of clinical use, twenty tubes segments were divided into two equal groups (with and without B-Safe, ten elements each) and were placed in test tubes containing 10.0 mL of BHI broth, which were incubated at 37°C in aerobic condition. After this time, serial decimal dilutions of 50.0 µL aliquots were made on two culture media: blood agar and sabourad dextrose agar, followed by the incubation of the Petri dishes at 37ºC in aerobiosis. Differences in microorganism counts (CFU/mL) were analyzed by Anova and Tukey (p ≤ 0.05). Results: there was turbidity of the culture medium in all test tubes of control group, and the counting of colonies formed revealed a high level of contamination in conventional tubes (blood agar: 2.025 CFU/mL and dextrose agar: 483 CFU/mL). The tubes of control group showed no turbidity or colonies forming units. Conclusion: the silver nanocoating incorporated into the waterline of the dental office can prevent contamination during clinical procedures for implant-supported prostheses

Adsorção de Candida albicans em resinas utilizadas em bases de próteses removíveis / Adsorption of Candida albicans in resins used for manufacture of removable prosthesis bases

A resina acrílica termoativada tem sido o material de escolha para confecção de bases de próteses removíveis há mais de 60 anos. Mais recentemente, as resinas ativadas por micro-ondas e as semi-rígidas foram introduzidas, porém pouco ainda se sabe a respeito da capacidade de retenção de biofilme nesses materiais, especialmente do último. Esse estudo avaliou a adsorção de Candida albicans em quatro resinas utilizadas em bases de próteses removíveis. Os materiais avaliados foram: Onda-Cryl (Clássico, polimerização por microondas), QC-20 (Dentsply, polimerização térmica de ciclo curto), Lucitone (Denstply, polimerização térmica) e Odontoflex (Odontoloflex, resina de poliamida termo-injetada). Dez corpos-de-prova (10,0X5,0X2,0mm) foram preparados para cada material, de acordo com as recomendações dos fabricantes. Os corpos-de-prova foram esterilizados (121ºC, 25min, 1 atm), colocados em tubos contendo 10,0mL de caldo RPMI (Inlab) inoculados com C. albicans ATCC 28366 (106 CFU/mL) e incubados em shaker (48h/37ºC). A seguir, os corpos-de-prova foram transferidos para outros tubos de ensaio e lavados com água destilada esterilizada (10s), sendo novamente colocados em caldo RPMI sob agitação (10s). Aliquotas do caldo RPMI foram semeadas em meio de cultura sólido agar Sabouraud (Difco), que foi então incubado (48h/37ºC). As colônias formadas foram contadas e os resultados analisados (Anova One-Way, Tukey, p≤0,05). De acordo com a adsorção de C. albicans ATCC 28366, os materiais foram classificados na seguinte ordem decrescente: 1) Odontoflex (690.000UFC/mL), 2) OndaCryl (454.000UFC/mL), 3) Lucitone 550 (256.000UFC/mL) e 4) QC-20 (254.000UFC/mL). Odontoflex e Onda-Cryl diferiram significantemente (p≤0,05) entre si e dos outros materiais. Lucitone 550 e QC-20 foram similares em termos de adsorção da levedura. Conclui-se que a maior retenção de C. albicans ATCC 28366 foi observada para a resina de poliamida e menor para a resina termoativada QC 20.

Heat-activated resin has been selected as material for the preparation of removable prosthesis basis for over 60 years. Microwave-activated and semi-rigid resins have been introduced more recently; however, little is known about their ability to retain biofilms, especially in the case of semi-rigid materials. Therefore, this study evaluated C. albicans adsorption onto four resins employed in removable prosthesis basis. The materials Onda-Cryl (Classic, microwave polymerization), QC-20 (Dentsply, short-cycle heat-activated polymerization), Lucitone (Denstply, heatactivated polymerization), and Odontoflex (Odontoloflex, thermally injected polyamide resin) were investigated. Ten specimens (10.0X5.0X2.0mm) were prepared for each material, following the manufacturer's instructions. The samples were sterilized (121ºC, 25min, 1 atm), placed in tubes containing 10.0 mL of RPMI broth (Inlab) inoculated with C. albicans ATCC 28366 (106 CFU/mL), and incubated in a shaker (48h/37ºC). Next, the specimens were transferred to other test tubes and washed with sterilized distilled water (10s), and were then placed in RPMI broth, under agitation (10s). Aliquots of the RPMI broth were seeded in solid agar Sabouraud culture medium (Difco), which was then incubated (48h/37ºC). The resulting colonies were counted, and the data were analyzed (Anova One-Way, Tukey, p≤0.05). On the basis of C. albicans ATCC 28366 adsorption, the materials were classified in the following decreasing order: 1) Odontoflex (690,000CFU/mL), 2) Onda-Cryl (454,000CFU/mL), 3) Lucitone 550 (256,000CFU/mL), and 4) QC-20 (254,000CFU/mL). Odontoflex and Onda-Cryl were significantly different (p≤0.05), and they were also statistically different from the other tested materials. Lucitone 550 and QC-20 were similar in terms of yeast adsorption. In conclusion, larger and smaller C. albicans ATCC 28366 retention were verified for the polyamide resin and the heat-activated resin QC 20, respectively.

Assessment of antimicrobial effect of Biosilicate® against anaerobic, microaerophilic and facultative anaerobic microorganisms.

This study assessed the antimicrobial activity of a new bioactive glass-ceramic (Biosilicate®) against anaerobic, microaerophilic, and facultative anaerobic microorganisms. Evaluation of the antimicrobial activity was carried out by three methods, namely agar diffusion, direct contact, and minimal inhibitory concentration (MIC). For the agar diffusion technique, bio glass-ceramic activity was observed against various microorganisms, with inhibition haloes ranging from 9.0 ± 1.0 to 22.3 ± 2.1 mm. For the direct contact technique, Biosilicate® displayed activity against all the microorganisms, except for S. aureus. In the first 10 min of contact between the microorganisms and Biosilicate®, there was a drastic reduction in the number of viable cells. Confirming the latter results, MIC showed that the Biosilicate® inhibited the growth of microorganisms, with variations between ≤ 2.5 and 20 mg/ml. The lowest MIC values (7.5 to ≤ 2.5 mg/ml) were obtained for oral microorganisms. In conclusion, Biosilicate® exhibits a wide spectrum of antimicrobial properties, including anaerobic bacteria.

A influência da disposição das cerdas de escovas dentais manuais na remoção de placa dental / The influence of manual toothbrush bristle arrangement on dental plaque removal

This crossover study aimed to compare plaque removal efficiency of two manual toothbrushes with identical design, the exception being the pattern of bristle arrangement. Twenty-six subjects were selected following inclusion and exclusion criteria. Dental plaque was scored before and after seven days of use of each toothbrush (Sanifill Smooth® – T1 andSanifill Active Smooth® – T2) employing the Turesky Plaque Index. Plaque Index values were handled with parametrical statistics employing Analysis of Variance (p<0.05) and, later, the Tukey Test. At the end of the trial, each subject was asked which toothbrush they preferred. Results: plaque scores for toothbrush T1 were not statistically different from those for toothbrush T2. Subjects showed a distinct preference for toothbrush T1. Conclusion: there was no differencein terms of plaque removal when toothbrushes T1 and T2 were compared, although patients showed a higher preference for toothbrush T1. Thus the different toothbrushes bristles arrangements did not influence the dental plaque removal.

Este estudo cruzado se propôs a comparar a eficiência de remoção de placa dental de duas escovas manuais com modelos idênticos, exceto para o padrão da disposição das cerdas. Vinte e seis sujeitos foram selecionados de acordo com critérios de inclusão e exclusão. Placa dental foi mensurada antes e após sete dias de uso com cada uma das escovas (Sanifill Smooth® – T1 and Sanifill Active Smooth® – T2) utilizando-se o Índice de Placa de Turesky. No final do estudo, cada paciente foi questionado sobre qual a escova preferida. Os valores do Índice de Placa para T1 não foram estatisticamente diferentes para os da escova T2. Não houve diferença em termos de remoção de placa quando as escovas T1 e T2 foram comparadas, embora os pacientes tenham demonstrado grande preferência pela escova T1. Assim, as diferenças nas disposições das cerdas das escovas dentais manuais não influenciaram na remoção de placa dental.

Color stability of dental ceramics submitted to artificial accelerated aging after repeated firings.

STATEMENT OF PROBLEM: Color stability is an important factor to ensure the long-term clinical success of ceramic restorations. There is a lack of information on how color is affected by fabrication procedures, such as the number of firings. PURPOSE: The purpose of this study was to evaluate the effects that the number of firings and type of substrate have on the color stability of dental ceramic submitted to artificial accelerated aging. MATERIAL AND METHODS: Sixty specimens were fabricated: 30 metal ceramic (Verabond II + IPS d.SIGN) and 30 all-ceramic (IPS d.SIGN). Specimens were divided into 3 groups (n=10), and submitted to 2, 3, or 4 firings (+/-900 degrees C), respectively, according to the manufacturer's instructions. Color readings were obtained with a spectrophotometer before and after artificial accelerated aging, and L*, a*, and b* coordinates and total color variation (Delta E) were analyzed (2-way ANOVA, Bonferroni, alpha=05). RESULTS: For metal ceramic specimens, differences for the L* coordinates were significant (P<.05) only for the group submitted to 3 firings. With respect to the all-ceramic specimens, smaller L* coordinates were obtained for greater a* and b* coordinates, indicating that the greater the number of firings, the darker and more reddish/yellowish the specimen. All Delta E values, for all groups, were below 1.0. All-ceramic specimens submitted to 3 and 4 firings presented Delta E means differing statistically (P<.05) from those of the metal ceramic group. CONCLUSIONS: The type of substrate and number of firings affected the color stability of the ceramic material tested. Artificial accelerated aging did not produce perceptible color stability changes (Delta E<1.0).

Polymerization shrinkage stress of composites photoactivated by different light sources.

The purpose of this study was to compare the polymerization shrinkage stress of composite resins (microfilled, microhybrid and hybrid) photoactivated by quartz-tungsten halogen light (QTH) and light-emitting diode (LED). Glass rods (5.0 mm x 5.0 cm) were fabricated and had one of the surfaces air-abraded with aluminum oxide and coated with a layer of an adhesive system, which was photoactivated with the QTH unit. The glass rods were vertically assembled, in pairs, to a universal testing machine and the composites were applied to the lower rod. The upper rod was placed closer, at 2 mm, and an extensometer was attached to the rods. The 20 composites were polymerized by either QTH (n=10) or LED (n=10) curing units. Polymerization was carried out using 2 devices positioned in opposite sides, which were simultaneously activated for 40 s. Shrinkage stress was analyzed twice: shortly after polymerization (t40s) and 10 min later (t10min). Data were analyzed statistically by 2-way ANOVA and Tukey's test (alpha=5%). The shrinkage stress for all composites was higher at t10min than at t40s, regardless of the activation source. Microfilled composite resins showed lower shrinkage stress values compared to the other composite resins. For the hybrid and microhybrid composite resins, the light source had no influence on the shrinkage stress, except for microfilled composite at t10min. It may be concluded that the composition of composite resins is the factor with the strongest influence on shrinkage stress.

Polymerization shrinkage stress of composites photoactivated by different light sources

The purpose of this study was to compare the polymerization shrinkage stress of composite resins (microfilled, microhybrid and hybrid) photoactivated by quartz-tungsten halogen light (QTH) and light-emitting diode (LED). Glass rods (5.0 mm x 5.0 cm) were fabricated and had one of the surfaces air-abraded with aluminum oxide and coated with a layer of an adhesive system, which was photoactivated with the QTH unit. The glass rods were vertically assembled, in pairs, to a universal testing machine and the composites were applied to the lower rod. The upper rod was placed closer, at 2 mm, and an extensometer was attached to the rods. The 20 composites were polymerized by either QTH (n=10) or LED (n=10) curing units. Polymerization was carried out using 2 devices positioned in opposite sides, which were simultaneously activated for 40 s. Shrinkage stress was analyzed twice: shortly after polymerization (t40s) and 10 min later (t10min). Data were analyzed statistically by 2-way ANOVA and Tukey's test (a=5 percent). The shrinkage stress for all composites was higher at t10min than at t40s, regardless of the activation source. Microfilled composite resins showed lower shrinkage stress values compared to the other composite resins. For the hybrid and microhybrid composite resins, the light source had no influence on the shrinkage stress, except for microfilled composite at t10min. It may be concluded that the composition of composite resins is the factor with the strongest influence on shrinkage stress.

Este estudo comparou a contração de polimerização de resinas compostas fotoativadas por luz halógena (QTH) e diodo emissor de luz (LED). Foram confeccionados bastões de vidro (5,0 mm x 5,0 cm), e uma de suas extremidades sofreu jateamento com óxido de alumínio, sobre a qual foi aplicado um adesivo e fotoativado com luz halógena. Os bastões de vidro foram acoplados verticalmente, em pares, em uma máquina universal de ensaios (EMIC DL-2000) e as resinas compostas aplicadas no bastão inferior. A distância entre os bastões foi padronizada em 2 mm e um extensômetro foi acoplado a eles. As resinas foram fotoativadas (n=20), sendo 10 por QTH e 10 por LED utilizando dois aparelhos posicionados em lados opostos, acionados simultaneamente por 40 s. A tensão de contração foi analisada em dois momentos: logo após a polimerização (t40s) e 10 min após (t10min). A tensão de contração apresentada por todas as resinas foi maior em t10min do que em t40s, independente da fonte ativadora. A resina de micropartículas apresentou menores valores de tensão de contração com valores estatisticamente significantes em relação às demais resinas. Para as resinas híbrida e microhíbrida não houve influência da unidade ativadora sobre a tensão de contração, com exceção para a resina de micropartículas em t10min. Concluiu-se que a composição da resina composta foi o fator que mais interferiu na tensão de contração da resina composta.

Effectiveness of a new toothbrush design versus a conventional tongue scraper in improving breath odor and reducing tongue microbiota.

For centuries, specific instruments or regular toothbrushes have routinely been used to remove tongue biofilm and improve breath odor. Toothbrushes with a tongue scraper on the back of their head have recently been introduced to the market. The present study compared the effectiveness of a manual toothbrush with this new design, i.e., possessing a tongue scraper, and a commercial tongue scraper in improving breath odor and reducing the aerobic and anaerobic microbiota of tongue surface. The evaluations occurred at 4 moments, when the participants (n=30) had their halitosis quantified with a halimeter and scored according to a 4-point scoring system corresponding to different levels of intensity. Saliva was collected for counts of aerobic and anaerobic microorganisms. Data were analyzed statistically by Friedman's test (p<0.05). When differences were detected, the Wilcoxon test adjusted for Bonferroni correction was used for multiple comparisons (group to group). The results confirmed the importance of mechanical cleaning of the tongue, since this procedure provided an improvement in halitosis and reduction of aerobe and anaerobe counts. Regarding the evaluated methods, the toothbrush's tongue scraper and conventional tongue scraper had a similar performance in terms of breath improvement and reduction of tongue microbiota, and may be indicated as effective methods for tongue cleaning.

Effectiveness of a new toothbrush design versus a conventional tongue scraper in improving breath odor and reducing tongue microbiota

For centuries, specific instruments or regular toothbrushes have routinely been used to remove tongue biofilm and improve breath odor. Toothbrushes with a tongue scraper on the back of their head have recently been introduced to the market. The present study compared the effectiveness of a manual toothbrush with this new design, i.e., possessing a tongue scraper, and a commercial tongue scraper in improving breath odor and reducing the aerobic and anaerobic microbiota of tongue surface. The evaluations occurred at 4 moments, when the participants (n=30) had their halitosis quantified with a halimeter and scored according to a 4-point scoring system corresponding to different levels of intensity. Saliva was collected for counts of aerobic and anaerobic microorganisms. Data were analyzed statistically by Friedman's test (p<0.05). When differences were detected, the Wilcoxon test adjusted for Bonferroni correction was used for multiple comparisons (group to group). The results confirmed the importance of mechanical cleaning of the tongue, since this procedure provided an improvement in halitosis and reduction of aerobe and anaerobe counts. Regarding the evaluated methods, the toothbrush's tongue scraper and conventional tongue scraper had a similar performance in terms of breath improvement and reduction of tongue microbiota, and may be indicated as effective methods for tongue cleaning.

Atividade antibacteriana do extrato hidroalcoólico bruto de Stryphnodendron adstringens sobre microorganismos da cárie dental / Antibacterial activity of the crude hydroalcoholic extract of Stryphnodendron adstringens on dental caries microorganisms

Objetivo: O Stryphnodendron adstringens (barbatimão) é uma leguminosa do cerrado brasileiro, considerada como planta medicinal devido à sua ação cicatrizante, antiinflamatória, hemostática, anti-séptica e anti-diarréica. Este trabalho avaliou a atividade antibacteriana do extrato hidroalcoólico bruto do barbatimão contra microrganismos da cárie dental. Metodologia: Para determinação da Concentração Inibitória Mínima (CIM) do extrato hidroalcoólico bruto de barbatimão sobre as cepas padrão Enterococcus faecalis, Streptococcus salivarius, Streptococcus sanguinis, Streptococcus mitis, Streptococcus mutans, Streptococcus sobrinus e Lactobacillus casei foi utilizado o método da diluição em caldo. Resultados: O extrato hidroalcoólico bruto de barbatimão foi ativo frente aos microrganismos S. mitis e L. casei. A CIM do extrato do barbatimão variou de 350 a >400µg/mL. Conclusão: A ação antibacteriana observada sugere o uso do extrato de barbatimão como adjuvante no controle da cárie dental.

Purpose: Stryphnodendron adstringens ('barbatimão') is a medicinal plant of the Leguminoseae family from the Brazilian 'cerrado'. This plant is used in folk medicine because of its healing, anti-inflammatory, antiseptic, and hemostatic effects. The aim of this work was to evaluate the antibacterial activity of the 'barbatimão' crude hydroalcoholic extract against cariogenic microorganisms. Methods: The broth dilution method was used to determine the Minimum Inhibitory Concentration (MIC) of the 'barbatimão' hydroalcoholic extract against Enterococcus faecalis, Streptococcus salivarius, Streptococcus sanguinis, Streptococcus mitis, Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus casei. Results: The 'barbatimão' hydroalcoholic extract showed antibacterial activity against S. mitis e L. casei, with MIC ranging from 350 to >400µg/mL. Conclusion: These results suggest that the 'barbatimão' hydroalcoholic extract might be used as an adjuvant measure to control dental caries.

Effect ofartificial accelerated aging on color stability and surface roughness of indirect composites.

Direct and indirect composite resins have different forms of polymerization. Some materials require a post-cure system associating light and heat enhancing clinical properties. This study assessed the changes in color and surface roughness of three indirect composite resins after accelerated aging. Twelve specimens (15 x 2 mm) were obtained for each tested material. Subsequently, the first measurements for roughness tests and colorimetric spectrophotometry (CIE L*a*b* scale) were performed. Specimens were subject to accelerated aging for 384 hours. New measurements were then performed to evaluate the resulting change. Accelerated aging produced color change and increased surface roughness in all composite resins. Solidex resin showed color changes above the clinically accepted value (DeltaE = 4.31 +/- 0.22), and roughness values (Ra = 0.088 +/- 0.008 microm) statistically lower than that of Artglass (Ra = 0.141 +/- 0.026 microm) and Targis (Ra = 0.124 +/- 0.02 microm) (p<0.001). All the indirect resins tested showed color change and increased roughness after accelerated aging. Solidex showed color stability above a quantitative level considered clinically acceptable and lower roughness values compared to the other resins.