Rational design of EDTA-incorporated nanoflowers as novel and effective endodontic disinfection against biofilms.

The ethylenediaminetetradiacetic acid (EDTA) is one of the most commonly used irrigation solutions. Although EDTA has a very low antimicrobial property, it is used to remove inorganic part of smear layer in areas of root canal system. Herein, we developed EDTA-incorporated nanoflowers (EDTA NFs), for the first time, as novel and effective irrigation solution with quite high antimicrobial property to provide complete disinfection in root canal system. We both systematically elucidated the formation of the EDTA NFs with various techniques, and their catalytic and antimicrobial activities in the presence of hydrogen peroxide (H2O2) were documented through intrinsic EDTA property and peroxidase-like activities.

Effect of different coronal restorations on the fracture resistance of teeth with simulated regenerative endodontic treatment: An in vitro study.

This study investigated the effect of different coronal restorations on the fracture resistance (FR) of immature teeth with simulated regenerative endodontic treatment. A total of 120 lower premolars were divided into eight groups. Except for negative control, the root canals were instrumented with rotary files and Peeso reamers. Fifteen instrumented teeth were acted as positive control (unrestorated). In the remaining 90 teeth, regenerative endodontic treatment procedures were performed. Ninety teeth were randomly divided into 6 groups according to coronal restoration type; Filtek Z550, Filtek Bulk fill Restorative (FBR), SDR+Filtek Z550, EverX+Filtek Z550, Ribbond+FBR and Ribbond+SDR+Filtek Z550. After thermal ageing, the restorated teeth were subjected to vertical loading force. FR values was obtained as follows: Negative control > Ribbond+FBR = Ribbond+SDR+Filtek Z550 > Filtek Z550 = FBR =SDR+Filtek Z550 = EverX+Filtek Z550 > Positive control, (P < 0.05). The use of Ribbond in combination with composite resin enhanced the FR of teeth.

Effect of two different temperatures on resistance to cyclic fatigue of one Curve, EdgeFile, HyFlex CM and ProTaper next files.

This study compared the cyclic fatigue resistance (CFR) of three controlled memory (CM) nickel-titanium rotary files (One Curve, EdgeFile and HyFlex CM) in comparison with a file (ProTaper Next) made from M-wire nickel-titanium alloy at two different temperatures (room and intracanal) in an s-shaped canal. One hundred and sixty files were tested to determine the CFR of OneCurve, EdgeFile, HyFlex CM and ProTaper Next in an artificial canal at room and at intracanal temperature. The number of cycles to failure was recorded, and data were analysed. At both temperatures, ProTaper Next exhibited the lowest CFR compared with the other files (P < 0.05). At room temperature, there was no difference among the three CM files regarding CFR (P > 0.05). At intracanal temperature, OneCurve and EdgeFile exhibited more CFR than the HyFlex CM (P < 0.05). Testing at intracanal temperature caused a significant decrease in CFR of all tested files compared with testing at room temperature.