ABSTRACT
Since recurrent caries are one of the major causes of failure in resin restorations, the production of antibacterial resin composites was always under investigation. The aim of this study was to evaluate the efficacy of fissure sealants containing nanosilver particles against the Streptococcus mutans. In this experimental study, the antibacterial properties of two sealants [with fluoride [Clinpro 3M] and without fluoride [Concise 3M] was investigated with 0, 0.01, 0.02, 0.03, 0.04, 0.05% w/w after adding nano-silver using direct contact test. Sealants formed on the walls of 500ml micro tube and after curing, they left in contact with bacterial suspension. In periods of 3, 24, 48h, a 10 microl volume of liquid medium was placed in blood agar culture and after 24 h incubation at 37°C, the number of S.mutans colony was counted by colony counter. Data were analyzed using ANOVA and T-test. Results reported sealants with fluoride comparing to non fluoride ones had significant effect on inhibition of S.mutans growth [P<0.001]. The direct contact test demonstrated that by increasing the amount of nano particles, the bacterial growth was significantly diminished [P<0.001]. While sealants with fluoride demonstrated antibacterial effect, sealants with incorporation of higher weight percentage of nanosilver particles, had stronger and more significant antibacterial effect in direct contact test
ABSTRACT
The aim of this study was to evaluate and compare the in vitro effect of the Erbium-Doped Yttrium Aluminum Garnet [Er:YAG] laser with different radiation distances and high-speed rotary treatment on the shear bond strength of flowable composite to enamel of human permanent posterior teeth. Freshly extracted human molar teeth with no caries or other surface defects were used in this study [n=45]. The teeth were randomly divided into 3 groups. Group 1: treated with non-contact Er:YAG Laser and etched with Er:YAG laser, Group 2: treated with contact Er:YAG Laser and etched with Er:YAG laser, Group 3 [control]: treated with diamond fissure bur and etched with acid phosphoric 37%. Then the adhesive was applied on the rtemisi of the teeth and polymerized using a curing light appliance. Resin cylinders were fabricated from flowable composite. Shear bond strength was tested at a crosshead speed of 0.5 mm/min. The amount of Shear Bond Strength [SBS] in the 3 treatment groups was not the same [P<0.05] .The group in which enamel surfaces were treated with diamond fissure bur and etched with acid [rtemis group] had the highest mean shear bond strength [19.92 +/- 4.76] and the group in which the enamel surfaces were treated with contact Er:YAG laser and etched with Er:YAG laser had the lowest mean shear bond strength [10.89 +/- 2.89]. Mann-whitney test with adjusted P-value detected significant difference in shear bond strength between the control group and the other 2 groups [P < 0.05]. It was concluded that both contact and non-contact Er:YAG laser treatment reduced shear bond strength of flowable resin composite to enamel in comparison with conventional treatment with high speed rotary. Different Er:YAG laser distance irradiations did not influence the shear bond strength of flowable composite to enamel
ABSTRACT
Mesiodens is the most common supernumerary tooth occurring in 0.15% to 1.9% of The population. A racial variation is believed in the prevalence of supernumeraries. The purpose of This cross-sectional study was to determine the prevalence of mesiodens. 2687 Iranian children 6-9 years old were selected and peripcal radiographs were taken. The general prevalence of mesiodens was found to be 1.6% [1.11, 2.08]. Males showed a higher prevalence of mesiodens than that of females 5:10. A maxillary occlusal radiograph is highly recommended to make clear. The presence or absence of supernumerary teeth