Under the experimental conditions, ProTaper left significantly less gutta-percha and sealer than Mtwo instruments. Complete removal of materials did not occur with any of the instrument systems investigated.

This study evaluated the antibacterial effects, physical properties and bonding strengths of conventional glass-ionomer cements (GICs) containing antibiotics and determined the optimal concentration of antibiotics addition for use with the ART approach. Fuji IX GIC was used as a control. Three antibiotic mixtures, ciprofloxacin, metronidazole and minocycline, were added to powdered GIC (Fuji IX) to obtain concentration ratios of 1.5, 3.0 and 4.5% w/w. The antibacterial activity of each GIC was evaluated against Streptococcus mutans or Lactobacillus casei using agar-diffusion methods. The release of antibiotics was analyzed by high-performance liquid chromatography (HPLC). The compressive strength and bonding strength to dentin were measured and compared with those of control samples. The results were analyzed using the Mann-Whitney test and Wilcoxon test. All tested groups showed a significantly greater inhibition with growth of the selected bacteria in comparison to the control groups (p < 0.01). However, the 3% and 4.5% concentration ratios of antibiotics had significantly lower compressive strength and lower bond strength to dentin than the control group (p = 0.003). The GIC-containing antibiotics were effective in inhibiting S Mutans and L Casei. The addition of a 1.5% antibiotic mixture was optimal to giving appropriate physical and bonding properties.

None of the techniques removed the Ca(OH)(2) dressing completely. CanalBrush and ultrasonic agitation of NaOCl were significantly more effective than irrigant-only techniques.

No abstract

Hero 642 rotary instruments transported canals less, especially at the middle and coronal thirds of the root canals than stainless steel K-files. Hero 642 instruments had better centreing ability.