Author/Authors :
Fedorovna Byakova, Svetlana Department of Therapeutic Dentistry - Institute of Dentistry - I.M. Sechenov First Moscow State Medical University (Sechenov University) of the Ministry of Health of the Russian Federation - Mojaiskii val str - Moscow, Russia , Dezhurko-Korol, Viktoriya Andreevna Department of Therapeutic Dentistry - Institute of Dentistry - I.M. Sechenov First Moscow State Medical University (Sechenov University) of the Ministry of Health of the Russian Federation - Mojaiskii val str - Moscow, Russia , Novozhilova, Nina Evgenievna Department of Therapeutic Dentistry - Institute of Dentistry - I.M. Sechenov First Moscow State Medical University (Sechenov University) of the Ministry of Health of the Russian Federation - Mojaiskii val str - Moscow, Russia , Makeeva, Irina Mikhailovna Department of Therapeutic Dentistry - Institute of Dentistry - I.M. Sechenov First Moscow State Medical University (Sechenov University) of the Ministry of Health of the Russian Federation - Mojaiskii val str - Moscow, Russia , Lukashev, Alexander Nikolaevich E.I. Martsinovsky Institute of Medical Parasitology and Tropical Medicine - I.M. Sechenov First Moscow State Medical University (Sechenov University) - M. Pirogovskaya str - Moscow, Russia , Akhmadishina, Ludmila Vasilievna E.I. Martsinovsky Institute of Medical Parasitology and Tropical Medicine - I.M. Sechenov First Moscow State Medical University (Sechenov University) - M. Pirogovskaya str - Moscow, Russia , Semenov, Alexandr Mikhailovich Department of Biology - Lomonosov Moscow State University - Leninskie Gory - Moscow, Russia , Moisenovich, Mihail Mikhailovich Department of Biology - Lomonosov Moscow State University - Leninskie Gory - Moscow, Russia , Arkhipova, Anastasia Yurievna Department of Biology - Lomonosov Moscow State University - Leninskie Gory - Moscow, Russia , Ponirovsky, Evgeny Nikolaevich E.I. Martsinovsky Institute of Medical Parasitology and Tropical Medicine - I.M. Sechenov First Moscow State Medical University (Sechenov University) - M. Pirogovskaya str - Moscow, Russia
Abstract :
Introduction: This study aimed at assessing the quantitative effect of calcium hydroxide, 2% chlorhexidine gel, and 1.5% chlorhexidine linked to xanthan gel specifically against intratubular bacteria. Methods and Materials: Fifty-two semi-cylindrical bovine dentin specimens were infected with Enterococcus (E.) faecalis by centrifugation with subsequent 7-days incubation. The surface of specimens was disinfected with 3% H2O2. Scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and the count of bacterial colony-forming units (CFU/mg) were used to assess dentin infection. A total of 40 specimens were incubated for 2 weeks with one of the intracanal medication applied (10 samples for each group): 1) calcium hydroxide, 2) 2% chlorhexidine gel, 3) 1.5% chlorhexidine linked to xanthan gel and 4) sterile saline. Final passive ultrasonic irrigation with 3% sodium hypochlorite was performed in half of the total specimens. The effect of intracanal medications and irrigation against intratubular bacteria was assessed by bacterial culturing of dentin shavings. Two-Way ANOVA model was applied followed by post-hoc Tukey's test for multiple pair-wise comparisons of mean CFU/mg values. Results: SEM, CLSM, and bacterial culturing confirmed the absence of the surface biofilm on the root canal wall and showed vital intratubular bacteria at the depth up to 700 mm. Two-week application of 1.5% chlorhexidine with xanthan gel and 2% chlorhexidine gel significantly decreased intratubular bacterial counts compared with saline (P=0.0003 and P=0.0005, respectively). Subsequent passive ultrasonic irrigation with 3% sodium hypochlorite significantly reduced the number of intratubular bacteria in all groups except for the group with 1.5% chlorhexidine-xanthan gel (P=0.0054). Conclusion: This modified ex vivo model study showed ultrasonically activated irrigation with sodium hypochlorite had greater effect on intratubular bacteria counts compared with 2-week application of intracanal medications.
Keywords :
Confocal Laser Scanning Microscopy , Electron Scanning Microscopy , Enterococcus faecalis , Root Canal Irrigants
