Streptococcus Mutans Biofilm Influences on the Antimicrobial Properties of Glass Ionomer Cements.

The aim of this study was to evaluate the in vitro antibacterial and biofilm inhibition properties of glass ionomer restorative cements. Ketac Nano, Vitremer, Ketac Molar Easymix and Fuji IX were analyzed using the following tests: a) agar plate diffusion test to evaluate the inhibitory activity of cements against S. mutans (n=8); b) S. mutans adherence test by counting colony-forming units after 2 h of material/bacteria exposure (n=10); c) biofilm wet weight after seven days of bacterial accumulation on material disks, with growth medium renewed every 48 h (n=10); d) pH and fluoride measurements from the medium aspired at 48 h intervals during the 7-day biofilm development (n=10). Data from the a, b and c tests were submitted to Kruskal-Wallis and Mann-Whitney tests and the fluoride-release and pH data were submitted to two-way ANOVA and Tukey tests (a=5%). Vitremer followed by Ketac Nano showed the greatest inhibitory zone against S. mutans than the conventional ionomers. Vitremer also showed higher pH values than Ketac Nano and Fuji IX in the first 48 h and released higher fluoride amount than Ketac Nano e Ketac Molar Easymix throughout the experimental period. The chemical composition of restorative glass ionomer materials influenced the antibacterial properties. The resin modified glass ionomer (Vitremer) was more effective for inhibition of S. mutans and allowed greater neutralization of the pH in the first 48 h. However, the type of glass ionomer (resin modified or conventional) did not influence the weight and adherence of the biofilm and fluoride release.

Streptococcus Mutans Biofilm Influences on the Antimicrobial Properties of Glass Ionomer Cements

Abstract The aim of this study was to evaluate the in vitro antibacterial and biofilm inhibition properties of glass ionomer restorative cements. Ketac Nano, Vitremer, Ketac Molar Easymix and Fuji IX were analyzed using the following tests: a) agar plate diffusion test to evaluate the inhibitory activity of cements against S. mutans (n=8); b) S. mutans adherence test by counting colony-forming units after 2 h of material/bacteria exposure (n=10); c) biofilm wet weight after seven days of bacterial accumulation on material disks, with growth medium renewed every 48 h (n=10); d) pH and fluoride measurements from the medium aspired at 48 h intervals during the 7-day biofilm development (n=10). Data from the a, b and c tests were submitted to Kruskal-Wallis and Mann-Whitney tests and the fluoride-release and pH data were submitted to two-way ANOVA and Tukey tests (a=5%). Vitremer followed by Ketac Nano showed the greatest inhibitory zone against S. mutans than the conventional ionomers. Vitremer also showed higher pH values than Ketac Nano and Fuji IX in the first 48 h and released higher fluoride amount than Ketac Nano e Ketac Molar Easymix throughout the experimental period. The chemical composition of restorative glass ionomer materials influenced the antibacterial properties. The resin modified glass ionomer (Vitremer) was more effective for inhibition of S. mutans and allowed greater neutralization of the pH in the first 48 h. However, the type of glass ionomer (resin modified or conventional) did not influence the weight and adherence of the biofilm and fluoride release.

Resumo O objetivo neste estudo foi avaliar in vitro as propriedades antibacterianas e a inibição do biofilme de cimentos de ionômero de vidro restauradores. Ketac Nano, Vitremer, Ketac Molar Easymix and Fuji IX foram avaliados através dos seguintes testes: a) teste de difusão em ágar para avaliar a inibição de S. mutans nos cimentos (n=8); b) adesão de S. mutans pela contagem de unidades formadoras de colônia após 2h de exposição material/bactéria (n=10); c) peso do biofilme úmido após sete dias de acúmulo bacteriano nos discos do material, com meio de cultura renovado após 48 h (n=10); d) mensuração do pH e liberação de flúor do meio aspirado nos intervalos de 48 h durante 7 dias de crescimento do biofilme (n=10). Os dados dos testes a, b e c foram submetidos aos testes Kruskal-Wallis e Mann-Whitney e os dados de liberação de flúor e pH a ANOVA dois fatores e Tukey (a = 5%). Vitremer seguido pelo Ketac Nano mostrou maior zona de inibição contra S. mutans quando comparados aos ionômeros convencionais. Vitremer também apresentou valores de pH mais elevados do que Ketac Nano e Fuji IX nas primeiras 48 h e liberou maior quantidade de flúor do que Ketac Nano e Ketac Molar Easymix durante todo o período experimental. A composição química dos ionômeros de vidro restauradores influenciou nas propriedades antibacterianas. O ionômero de vidro modificado por resina (Vitremer) foi mais eficaz na inibição de S. mutans e permitiu maior neutralização do pH nas primeiras 48 h. No entanto, o tipo de ionômero de vidro (modificado por resina ou convencional) não influenciou no peso e adesão do biofilme e na liberação de flúor.

In situ bacterial accumulation on dental restorative materials. CLSM/COMSTAT analysis.

PURPOSE: To evaluate the influence of different restorative materials on the biofilm structure accumulated in situ. METHODS: 15 discs of each material (ceramic; resin composite; resin-modified and conventional glass-ionomers; amalgam) were adapted to palatal devices in order to accumulate biofilm in situ, under a cariogenic challenge (20% sucrose solution, 10x/day). After 7 days, the specimens were carefully removed and visualized by confocal laser scanning microscopy (CLSM). The images were analyzed qualitatively (descriptive analysis about cell viability and architecture) and quantitatively using COMSTAT software (area, bio-volume, mean thickness, maximum thickness and roughness coefficient of the biofilm). The statistical analysis was performed by using the Kolmogorov-Smirnov and Kruskal-Wallis tests (P ≤ 5%). RESULTS: The medians of the biofilm parameters analyzed showed no statistical difference regarding different materials. However, qualitatively, glass-ionomer cements and amalgam showed visually a prevalence of non-viable cells forming small clusters distributed by the biofilm, and voids were presented in smaller proportion in the biofilm volume compared to composite and ceramic.

Child toothbrush abrasion effect on ionomeric materials.

The purpose of the study was to evaluate the abrasive effect of different toothbrushes-soft-cross bristles (CB), extra-soft-parallel bristles (ES), and soft-parallel bristles (S)-on the surface roughness of conventional (C) and resin-modified (V) glass ionomer cements in vitro. Eight specimens of each material were prepared for each group: (1) V and CB; (2) V and ES; (3) V and S; (4) C and CB; (5) C and ES; and (6) C and S. Specimens were stored at 37 degrees C/24 hours and 100% humidity, polished, and initially analyzed with a surface roughness-measuring device. Next, they were fixed to the tooth-brushing device and abraded via toothbrushes, using a dentifrice slurry, performed at 250 cycles/minute with a 200 g load. The specimens were washed, dried, and analyzed identically with the same device. There was no significant interaction between material and toothbrush types. After tooth-brushing, V showed significantly higher surface roughness than C and CB and created higher surface roughness than S. No difference was observed between these toothbrushes and ES. Regardless of the toothbrush type used, resin-modified glass ionomer cement showed the highest roughness values.

The influence of 30-day-old Streptococcus mutans biofilm on the surface of esthetic restorative materials--an in vitro study.

OBJECTIVE: To evaluate the effects of Streptococcus mutans biofilm/restorative materials interaction on surface roughness, hardness and morphology of materials tested. METHODS: Empress 2 (E2), Filtek Supreme (FS), Vitremer (V) and Ketac Molar Easymix (KM) were tested. Twenty-five disks of each material were made and divided into three storage groups: (1) 100% relative humidity (n=5); (2) growth medium (BHI and 1% sucrose) (n=5); (3) S. mutans biofilm-growth medium (n=15). Before storage, hardness measurements were immediately obtained from group 1 specimens. After 30 days of storage, the specimens were cleaned in order to obtain the surface roughness and hardness values, besides morphology analysis by scanning electron microscopy. RESULTS: The surface roughness and hardness values obtained from E2 and FS specimens did not present statistically significant differences among the groups 1, 2 and 3 and between immediate and 30-day-old specimens of each material. However, group 3 specimens of V and KM showed statistically significant higher surface roughness means than other groups. Group 1 specimens of V and KM also showed higher hardness values than the immediate values. Group 3 specimens of V presented decreased hardness values compared with other groups. The scanning electron micrographs showed an increase in surface degradation from group 1 to group 3 for FS, V and KM. CONCLUSIONS: Thirty-day-old biofilm promotes a negative effect on the surface morphology of FS, V and KM, on the surface roughness of V and KM and on the hardness of V.