Umer Daood1, Abhishek Parolia2, Jukka Matinlinna3, Cynthia Yiu4, Hany Mohamed Aly Ahmed5, Amr Fawzy6. 1. Division of Clinical Dentistry, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Bukit Jalil, Wilayah Persekutuan Kuala Lumpur, Malaysia. Electronic address: umerdaood@imu.edu.my. 2. Division of Clinical Dentistry, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Bukit Jalil, Wilayah Persekutuan Kuala Lumpur, Malaysia. 3. Dental Materials Science, Applied Oral Sciences, Faculty of Dentistry, The University of Hong Kong, 34 Hospital Road, Sai Ying Pun, Hong Kong SAR, China. 4. Pediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Pokfulam, Hong Kong, China Hong Kong Special Administrative Region. 5. Department of Restorative Dentistry, Faculty of Dentistry, University of Malaya, 50603, Kuala Lumpur, Malaysia. 6. UWA Dental School, University of Western Australia, Nedlands, WA 6009, Australia.
Abstract
OBJECTIVES: Evaluate a new modified quaternary ammonium silane irrigant solution for its antimicrobial, cytotoxic and mechanical properties of dentine substrate. METHODS: Root canal preparation was performed using stainless steel K-files™ and F4 size protaper with irrigation protocols of 6% NaOCl + 2% CHX; 3.5% QIS; 2% QIS and sterile saline. Biofilms were prepared using E. faecalis adjusted and allowed to grow for 3 days, treated with irrigants, and allowed to grow for 7 days. AFM was performed and surface free energy calculated. MC3T3 cells were infected with endo irrigant treated E. faecalis biofilms. Raman spectroscopy of biofilms were performed after bacterial re-growth on root dentine and exposed to different irrigation protocols and collagen fibers analysed collagen fibers using TEM. Antimicrobial potency against E. faecalis biofilms and cytoxicity against 3T3 NIH cells were also. Resin penetration and MitoTracker green were also evaluated for sealer penetration and mitochondrial viability. Data were analysed using One-way ANOVA, principal component analysis and post-hoc Fisher's least-significant difference. RESULTS: Elastic moduli were maintained amongst control (5.5 ± 0.9) and 3.5% QIS (4.4 ± 1.1) specimens with surface free energy higher in QIS specimens. MC3T3 cells showed reduced viability in 6%NaOCl+2%CHX specimens compared to QIS specimens. DNA/purine were expressed in increased intensities in control and 6% NaOCl + 2% CHX specimens with bands around 480-490 cm-1 reduced in QIS specimens. 3.5% QIS specimens showed intact collagen fibrillar network and predominantly dead bacterial cells in confocal microscopy. 3.5% QIS irrigant formed a thin crust-type surface layer with cytoplasmic extensions of 3T3NIH spread over root dentine. Experiments confirmed MitoTracker accumulation in 3.5% treated cells. SIGNIFICANCE: Novel QIS root canal irrigant achieved optimum antimicrobial protection inside the root canals facilitating a toxic effect against the Enterococcus faecalis biofilm. Root dentine substrates exhibited optimum mechanical properties and there was viability of fibroblastic mitochondria.
OBJECTIVES: Evaluate a new modified quaternary ammonium silane irrigant solution for its antimicrobial, cytotoxic and mechanical properties of dentine substrate. METHODS: Root canal preparation was performed using stainless steel K-files™ and F4 size protaper with irrigation protocols of 6% NaOCl + 2% CHX; 3.5% QIS; 2% QIS and sterile saline. Biofilms were prepared using E. faecalis adjusted and allowed to grow for 3 days, treated with irrigants, and allowed to grow for 7 days. AFM was performed and surface free energy calculated. MC3T3 cells were infected with endo irrigant treated E. faecalis biofilms. Raman spectroscopy of biofilms were performed after bacterial re-growth on root dentine and exposed to different irrigation protocols and collagen fibers analysed collagen fibers using TEM. Antimicrobial potency against E. faecalis biofilms and cytoxicity against 3T3 NIH cells were also. Resin penetration and MitoTracker green were also evaluated for sealer penetration and mitochondrial viability. Data were analysed using One-way ANOVA, principal component analysis and post-hoc Fisher's least-significant difference. RESULTS: Elastic moduli were maintained amongst control (5.5 ± 0.9) and 3.5% QIS (4.4 ± 1.1) specimens with surface free energy higher in QIS specimens. MC3T3 cells showed reduced viability in 6%NaOCl+2%CHX specimens compared to QIS specimens. DNA/purine were expressed in increased intensities in control and 6% NaOCl + 2% CHX specimens with bands around 480-490 cm-1 reduced in QIS specimens. 3.5% QIS specimens showed intact collagen fibrillar network and predominantly dead bacterial cells in confocal microscopy. 3.5% QIS irrigant formed a thin crust-type surface layer with cytoplasmic extensions of 3T3NIH spread over root dentine. Experiments confirmed MitoTracker accumulation in 3.5% treated cells. SIGNIFICANCE: Novel QIS root canal irrigant achieved optimum antimicrobial protection inside the root canals facilitating a toxic effect against the Enterococcus faecalis biofilm. Root dentine substrates exhibited optimum mechanical properties and there was viability of fibroblastic mitochondria.