Nanostructural changes in dentine caused by endodontic irrigants

Abstract

Objective: To study nanostructural dentinal changes produced by endodontic irrigants. Study Design: Experimental study. Nanoindentations were performed on peritubular (PD) and intertubular dentine (ID) with an atomic force microscopy. Stiffness and adhesion force were determined before and after application of 5.25% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA). Normalized differences before and after treatment for stiffness and adhesion forces were calculated. A paired T-test was used to compare stiffnes and adhesion force before and after irrigants application. Results: After treatment with EDTA there was a 29.80% reduction in stiffness in ID and a 63.53% reduction in PD. Adhesion force was reduced by 21.22% and 8.21% respectively. After treatment with 5.25% NaOCI stiffness was reduced by 2.49% in ID and increased by 15.01% in PD. Adhesion force increased by 25.11% and 23.97% respectively. Conclusions: 17% EDTA reduced stiffness and adhesion force in ID and PD. Treatment with NaOCI at 5.25% had no significant effect on stiffness but did affect adhesion force in ID and PD. Key words:Atomic force microscope, stiffness, adhesion force, peritubular dentine, intertubular dentine.

Bioactive Chitosan Nanoparticles and Photodynamic Therapy Inhibit Collagen Degradation In Vitro

“…It has been known for some time that varying concentrations of chelating agents, such as EDTA, acids, and disinfecting agents such as sodium hypochlorite (NaOCl), have demonstrated an ability to undermine dentin microhardness and elasticity (60)(61)(62)(63), while a more recent study has reported that dentin subject to prolonged calcium hydroxide (CaOH) exposure, demonstrates a decreased resistance to fracture (162).…”

“…The use of 5.25% NaOCl has been reported to decrease Young's modulus of dentin, in addition to its flexural stress (62). Reduction in dentin elasticity after treatment with NaOCl has also been reported (60,61,63). This may be due to the dissolution of the organic component of the dentin by NaOCl.…”

“…Changes in the organic and inorganic components of dentin will affect the mechanical properties of dentin. Various concentrations of chelating agents, including ethylenediaminetetraacetic acid (EDTA) and citric acid, can reduce dentin microhardness (60,61,63). Sodium hypochlorite (NaOCl) is the most commonly used endodontic antimicrobial irrigant, which has the ability to dissolve the organic material.…”

Potensi Larutan Chitosan 0,2% Sebagai Alternatif Bahan Irigasi Dalam Perawatan Saluran Akar Gigi

“…Perubahan rasio kalsium-fosfat (Ca/P) di dentin dinding saluran akar oleh EDTA juga dapat merubah proporsi komponen organik dan inorganik yang berdampak mempengaruhi kekerasan, permeabilitas serta solubilitas dentin. 7 Sumber EDTA juga tidak dijumpai secara alamiah sehingga dianggap sebagai polutan. Mengingat masih dijumpainya kelemahan dari bahan irigasi NaOCL dan EDTA tersebut di atas, masih perlu dicari dan dikembangkan alternatif bahan irigasi yang bersifat biokompatibel, efektif dan aman sehingga dapat meminimalisasi dampak yang merugikan struktur gigi maupun jaringan periapikal.…”

Effect of gaseous ozone and light‐activated disinfection on the surface hardness of resin‐based root canal sealers

“…Generally, the hardness test can serve as an indirect method for measuring how well the materials have set. For example, higher values of hardness are indicative of more extensive polymerization of dental resins (Barón et al ., ). It has been reported that disinfection agents, especially peroxide‐based lubricants and NaOCl, can adversely affect the setting of resins that cure by a free‐radical polymerization mechanism (Onay et al ., ) and may indirectly affect surface hardness of resin‐based sealers.…”