Antimicrobial potential of essential oils mouthrinses with and without alcohol: a randomized clinical trial

Aim: This study aimed to compare the microbiological potential and gustatory perception of essential oils (EO) mouthrinses containing and not containing alcohol. Methods: Twenty healthy adult volunteers rinsed with 10mL of the following test solutions: EO with alcohol, EO without alcohol, or a control solution (saline solution with mint essence). A washout period of at least seven days was adopted after a single-use protocol of the respective solution. All participants used all three tested substances. Antimicrobial potential was assessed by counting salivary total viable bacteria both before and after each rinse. Gustatory perception was evaluated using the Visual Analogue Scale (VAS). Multiple comparisons were performed with the Wilcoxon test, using Bonferroni correction. Results: Both EO solutions presented a higher antimicrobial potential in comparison to the control solution (p<0.017). However, no significant difference in antimicrobial potential was observed between EO containing or not containing alcohol (p=0.218). VAS of EO with alcohol (median: 2.7) was similar to control solution (median: 1.6) (p=0.287). A better gustatory perception was observed of the EO without alcohol (median 7.6) when compared to the control solution (p<0.0001). When EO groups were compared, EO without alcohol also demonstrated a significantly better gustatory perception (p=0.001). Conclusion: Mouthrinse containing EO without alcohol presented a better taste perception when compared to the EO with alcohol, but no difference was observed in the antimicrobial potential of both EO solutions after a single rinse protocol

Role of Candida albicans on enamel demineralization and on acidogenic potential of Streptococcus mutans in vitro biofilms

Abstract There is growing evidence that C. albicans is associated with dental caries, but its role on caries development needs to be better clarified. Objective: To evaluate at the hard tissue level the effect of C. albicans on the cariogenic potential of S. mutans biofilms focusing on the mineral profile of induced carious lesions. This study also aimed to evaluate the effect of C. albicans on the acidogenic potential of S. mutans biofilms. Methodology: Dual-species (CA+SM) and single-species biofilms (CA or SM) were grown on the surface of enamel slabs in the presence of glucose/sucrose supplemented culture medium for 24, 48 and 72 hours. Demineralization was evaluated through percentage of surface microhardness change (%SMC) and transversal microradiography analysis (ILM and LD) and pH of the spent medium was recorded daily. Data were analyzed by two-way ANOVA followed by Bonferroni correction. Results: %SMC was statistically different among the biofilms at each time point being the highest for SM biofilms and the lowest for CA biofilms which also differed from CA+SM biofilms [SM (24 h: 47.0±7.3; 48 h: 66.3±8.3; 72 h: 75.4±3.9); CA (24 h: 7.3±3.3; 48 h: 7.1±6.4; 72 h: 6.6±3.6); CA+SM (24 h: 35.9±7.39.1; 48 h: 47.2±9.5; 72 h: 47.6±9.5)]. pH of spent medium was statistically lower for SM biofilms compared to the other biofilms at each time point and remained constant over time while pH values increased from 24 to 72 h for both CA and CA+SM biofilms [SM (24 h: 4.4±0.1; 48 h: 4.4±0.1; 72 h: 4.5±0.1); CA (24 h: 6.9±0.3; 48 h: 7.2±0.2; 72 h: 7.5±0.2); CA+MS (24 h: 4.7±0.2; 48 h: 5.1±0.1; 72 h: 6.1±0.6)]. IML and LD for SM biofilms increased over time while no difference was observed from 24 to 72 h for the other biofilms. Conclusions: The present data suggest that C. albicans has low enamel demineralization potential and the presence of C. albicans can reduce both the cariogenic and acidogenic potentials of S. mutans biofilms.

In vitro and in vivo evaluations of glass-ionomer cement containing chlorhexidine for Atraumatic Restorative Treatment

Abstract Objectives: Addition of chlorhexidine has enhanced the antimicrobial effect of glass ionomer cement (GIC) indicated to Atraumatic Restorative Treatment (ART); however, the impact of this mixture on the properties of these materials and on the longevity of restorations must be investigated. The aim of this study was to evaluate the effects of incorporating chlorhexidine (CHX) in the in vitro biological and chemical-mechanical properties of GIC and in vivo clinical/ microbiological follow-up of the ART with GIC containing or not CHX. Material and Methods: For in vitro studies, groups were divided into GIC, GIC with 1.25% CHX, and GIC with 2.5% CHX. Antimicrobial activity of GIC was analyzed using agar diffusion and anti-biofilm assays. Cytotoxic effects, compressive tensile strength, microhardness and fluoride (F) release were also evaluated. A randomized controlled trial was conducted on 36 children that received ART either with GIC or GIC with CHX. Saliva and biofilm were collected for mutans streptococci (MS) counts and the survival rate of restorations was checked after 7 days, 3 months and one year after ART. ANOVA/Tukey or Kruskal-Wallis/ Mann-Whitney tests were performed for in vitro tests and in vivo microbiological analysis. The Kaplan-Meier method and Log rank tests were applied to estimate survival percentages of restorations (p<0.05). Results: Incorporation of 1.25% and 2.5% CHX improved the antimicrobial/anti-biofilm activity of GIC, without affecting F release and mechanical characteristics, but 2.5% CHX was cytotoxic. Survival rate of restorations using GIC with 1.25% CHX was similar to GIC. A significant reduction of MS levels was observed for KM+CHX group in children saliva and biofilm 7 days after treatment. Conclusions: The incorporation of 1.25% CHX increased the in vitro antimicrobial activity, without changing chemical-mechanical properties of GIC and odontoblast-like cell viability. This combination improved the in vivo short-term microbiological effect without affecting clinical performance of ART restorations.

Analysis by confocal laser scanning microscopy of the MDPB bactericidal effect on S. mutans biofilm CLSM analysis of MDPB bactericidal effect on biofilm

Since bacteria remain in the dentin following caries removal, restorative materials with antibacterial properties are desirable to help maintaining the residual microorganisms inactive. The adhesive system Clearfil Protect Bond (PB) contains the antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide (MDPB) in its primer, which has shown antimicrobial activity. However, its bactericidal effect against biofilm on the dentin has been little investigated. Objective: The aim of this study was to analyze by confocal laser scanning microscopy (CLSM) and viable bacteria counting (CFU) the MDPB bactericidal effect against S. mutans biofilm on the dentin surface. Material and methods: Bovine dentin surfaces were obtained and subjected to S. mutans biofilm formation in BHI broth supplemented with 1% (w/v) sucrose for 18 h. Samples were divided into three groups, according to the primer application (n=3): Clearfil Protect Bond (PB), Clearfil SE Bond, which does not contain MDPB, (SE) and saline (control group). After the biofilm formation, Live/ Dead stain was applied directly to the surface of each sample. Next, 10 µL of each primer were applied on the samples during 590 s for the real-time CLSM analysis. The experiment was conducted in triplicate. The primers and saline were also applied on the other dentin samples during 20, 90, 300 and 590 s (n=9 for each group and period evaluated) and the CFU were assessed by colonies counting. Results: The results of the CLSM showed that with the Se application, although non-viable bacteria were detected at 20 s, there was no increase in their count during 590 s. In contrast, after the PB application there was a gradual increase of non-viable bacteria over 590 s. Conclusions: The quantitative analysis demonstrated a significant decrease of S. mutans CFU at 90 s PB exposure and only after 300 s of Se application. Protect Bond showed an earlier antibacterial effect than Se Bond.

Estudo microbiológico comparativo entre sabão de clorexidina 2% e um novo sabão antisséptico para lavagem pré-operatória das mãos / Microbiological study comparing 2% chlorhexidine soap and a new antiseptic soap for preoperative handwashing

Objetivos: avaliar, por meio de estudo microbiológico, dois tipos de sabão propostos para a lavagem das mãos na preparação dos cirurgiões no tempo pré-operatório; comparando um sabão com potência antibacteriana já conhecida e um novo sabão formulado a partir de óleos vegetais. Materiais e métodos: Dez voluntários fizeram a escovação das mãos, segundo protocolos pré-estabelecidos para a rotina de medidas de antissepsia em centros cirúrgicos, com 3 sabões diferentes, sendo um sabão comum (comercial) sem poder antisséptico que serviu como Grupo Controle (I), um sabão de digluconato de clorexidina a 2% (Grupo II) e um novo sabão feito a partir de óleos vegetais numa concentração de 20%, que foi desenvolvido pelo Instituto de Química Unesp/araraquara no Grupo de Materiais Fotônicos, denominado surfactante a 20% (Grupo III). antes de lavar as mãos, logo após e uma hora depois com o uso de luvas cirúrgicas, foi realizada a coleta microbiológica. Resultados: Pelos resultados da aNoVa, verificam-se as seguintes diferenças significativas para o número de colônias bacterianas: entre tipos de sabão (menor número de colônias no sabão do Grupo II), entre tempos (redução do número de colônias no sabão do Grupo II) e efeito significativo da interação sabão versus tempo. Conclusão: o sabão de digluconato de clorexidina 2% mostrou um comportamento melhor em reduzir o número de colônias bacterianas das mãos imediatamente após a lavagem e continuou sendo superior após uma hora com o uso de luvas, quando comparado ao sabão de surfactante a 20%.

Objective: To evaluate, by means of a microbiologic study, two kinds of soaps suggested by surgeons for presurgical handwashing, comparing a well-known antibacterial soap with a new soap formulated from vegetable oils. Materials and methods: Ten volunteers performed handwashing according to previously established protocols for routine antisepsis in operating rooms using 3 different soaps: a common, commercially marketed soap, serving as the control group (Group 1), with no antibacterial characteristics; a soap with 2% chlorhexidine (Group II); and a new soap formulated from vegetable oils at a concentration of 20%, known as surfactant, which was designed by the Chemistry Institute (Unesp/Araraquara - Grupo de Materiais Fotônicos) (Group III). The microbiological samples were collected immediately before and after handwashing and one hour later with the volunteer wearing surgical gloves. Results: ANOVA revealed that the following significant differences are found in the number of bacterial colonies: between soap types (a smaller number of colonies in the Group II soap), between periods (reduction in the number of colonies in the Group II soap), and the significant effect of the soap versus time interaction. Conclusion: The 2% chlorhexidine soap performed better in reducing the number of bacterial colonies on the hands immediately after handwashing and after one hour with the use of surgical gloves, when compared to the 20% surfactant soap.

Effect of light-activation on the antibacterial activity of dentin bonding agents

Aim: This study evaluated the effect of light-activation on the antibacterial activity of dentin bonding systems. Methods: Inocula of Streptococcus mutans and Lactobacillus casei cultures were spread on the surface of BHI agar and the materials were applied and subjected or not to light-activation. Zones of bacterial growth inhibition around the discs were measured. Results: Excite, Single Bond and the bond of Clearfil SE Bond (SE) and Clearfil Protect Bond (CP) did not show any antibacterial activity. The strongest inhibitory activity was observed for the primers of CP and Prompt (PR) against S. mutans and the primers of SE andPB against L. casei. Conclusion: Light-activation significantly reduced or suppressed the antibacterial activity of the initially active uncured dentin bonding systems.

Fundamental mechanisms of immune response to oral bacteria and the main perspectives of a vaccine against dental caries: a brief review / Mecanismos fundamentais de resposta imune contra bactérias bucais e as principais perspectivas para uma vacina anticárie: uma breve revisão

Dental caries may be defined as a complex multifatorial disease in that a broad group of biological, socio-economic and cultural factors interact directly or indirectly in the establishment and colonization of cariogenic microorganisms within the microbial community of the dental biofilm. Innate and adaptative immunity are two fundamental aspects of the immune system response against infections, such as dental caries. Besides, the majority of pathogenic infectious agents enter the organisms by the oral route. Consequently, the mucosal tissue, associated exocrine glands and saliva contributes to the protection of the oral cavity because contain cells responsible for antigen internalization and antibodies specific to oral bacteria. Macrophages are phagocytic cells that can internalize and kill bacteria by several mechanisms of internalization, including endocytosis, macropinocytosis and phagocytosis. Streptococcus mutans is the major pathogen of dental caries due to its ability to adhere and accumulate on tooth surfaces, using different virulence factors (AgI/II, Gtf, Gbps). Recent studies demonstrated protection against experimentally induced dental caries for vaccines containing intact or peptides from antigen I/II, Gtf or Gbp and vaccines containing a combination of antigens. The present review summarizes the fundamental mechanisms of host immune responses to oral bacteria and the main perspectives of a vaccine against dental caries.

A cárie dentária pode ser definida como uma doença complexa multifatorial causada por fatores biológicos, socioeconômicos e culturais que interagem direta ou indiretamente na colonização e estabelecimento de microrganismos cariogênicos na comunidade microbiana do biofilme dentário. As imunidades inata e adaptativa são os dois aspectos fundamentais de resposta do sistema imune contra infecções, como a cárie dentária. Além disso, a maioria dos agentes infecciosos patogênicos entra no organismo por via oral. Consequentemente, o tecido mucoso, associado com as glândulas exócrinas e a saliva contribuem para a proteção da cavidade bucal por conterem células responsáveis pela internalização de antígenos ou anticorpos contra as bactérias bucais. Os macrófagos são células fagocíticas que podem internalizar e eliminar bactérias por diversos mecanismos de internalização, como a endocitose, macropinocitose e fagocitose. Streptococcus mutans é o principal patógeno da cárie dentária por sua habilidade em aderir e acumular nas superfícies dentárias, usando diferentes fatores de virulência (AgI/II, Gtf e Gbps). Estudos recentes têm demonstrado proteção contra cárie induzida experimentalmente utilizando vacinas contendo antígenos intactos ou peptídeos a partir de AgI/II, Gtf ou Gbps ou uma combinação de antígenos. A presente revisão sumariza os mecanismos fundamentais de resposta imune contra bactérias bucais e as principais perspectivas de uma vacina anticárie.

Genetic polymorphism of Streptococcus mutans strains associated with incomplete caries removal

Aim: Despite the antibacterial properties of dental materials, the survival of residual bacteria under restorations has been demonstrated after incomplete caries removal. The aim of this study was to evaluate the genetic polymorphism of Streptococcus mutans strains isolated from deep dentinal lesions before and three months after incomplete caries removal. Methods: Samples of carious dentin were collected from 33 primary and/or permanent molars before and after indirect pulp treatment and processed for microbiological isolation of mutans streptococci (MS). After three months of the dental treatment, positive cultures for MS were detected in only ten of these teeth. DNA of MS isolates were obtained and subjected to polymerase chain reaction (PCR) for identification of S mutans. The arbitrary primed-PCR method (primer OPA-13) was used to detect the genetic polymorphism of S. mutans strains. Results: Identical or highly related S. mutans genotypes were observed in each tooth, regardless of the collect. Considering each tooth separately, a maximum of nine genotypic patterns were found in each tooth from all the collects. In addition, at least one genotypic pattern was repeated in the three collects. Genetic diversity was observed among the S. mutans isolates, obtained from different teeth after three months of the dental treatment. Conclusions: The persistence of identical genotypic patterns and the genetic similarity among the isolates, from the same tooth in distinct collects, showed the resistance of some S. mutans strains after incomplete caries removal treatment.

Genetic polymorphism of Streptococcus mutans in Brazilian family members

O objetivo deste estudo foi determinar, através da técnica de reacão em cadeia da polimerase com primers arbitrários (AP-PCR) a capacidade de diferenciar clones geneticamente distintos de Streptococcus mutans e estabelecer o grau de similaridade intrafamilial para os isolados. Para o presente estudo, foram selecionadas 22 famílias brasileiras. Amostras de saliva foram coletadas de todos os membros das famílias. Das criancas com idade entre 5-18 meses obteve-se amostras de placa dental. Após o isolamento das colônias com características morfológicas, realizou-se a identificacão bioquímica com base na fermentacão de carboidratos. O polimorfismo genético de Streptococcus mutans foi pesquisado através da técnica de AP-PCR utilizando-se o primer OPA-13. Os fragmentos de DNA obtidos foram amplificados e comparados através de eletroforese em gel de agarose. Dentre as espécies identificadas nas 22 famílias analisadas, o pai apresentou cepas com similaridade genética aos dos bebês em três das famílias analisadas; em 12 famílias a mãe apresentou cepas com similaridade com as cepas de Streptococcus mutans do bebê e 7 bebês apresentaram cepas de S. mutans com similaridade genética das cepas do irmão mais velho. A técnica de AP-PCR foi eficaz em demonstrar a heterogeneidade genética de Streptococcus mutans entre os membros das famílias brasileiras analisadas.