<p>The Effect of Silver, Zinc Oxide, and Titanium Dioxide Nanoparticles Used as Final Irrigation Solutions on the Fracture Resistance of Root-Filled Teeth</p>

Abstract

This study was conducted to evaluate the effect of three nanoparticle solutions used as final root canal irrigants on the fracture resistance of endodontically treated roots. Materials and Methods: Sixty intact single-rooted premolar teeth were used after removing the crowns below the cementum-enamel junction to standardize the length of the remaining roots to 13 mm. After instrumenting the roots using ProTaper Universal rotary instruments up to size F4, the roots were randomly divided into six groups (n=10) according to the final irrigating solutions: Group 1: normal saline; Group 2: 2% chlorhexidine (CHX); Group 3: 17% EDTA+2.5% NaOCl; Group 4: 17% EDTA+0.1% silver nanoparticle (SNP) solution; Group 5: 17% EDTA+0.1% titanium dioxide nanoparticle (TNP) solution; Group 6: 17% EDTA+0.1% zinc oxide nanoparticle (ZNP) solution. After filling the root canals with gutta-percha and AH Plus sealer, the fracture resistance (FR) values were measured. The data were subjected to the one-way analysis of variance and the Tamhane post hoc test (p=0.05). Results: EDTA + NaOCl had the lowest FR value, followed by normal saline and CHX (p values < 0.05). No significant difference was found between the FR of roots irrigated with CHX and normal saline (p > 0.05). The application of nanoparticles (SNP, TNP, and ZNP) was associated with a significantly greater FR than that of other irrigation solutions (p values < 0.05). Conclusion: The final irrigation of root canals with nanoparticles enhanced the fracture resistance of the endodontically treated roots. The lowest FR value was observed for NaOCl.

<p>The Effects of Silver, Zinc Oxide, and Titanium Dioxide Nanoparticles Used as Dentin Pretreatments on the Microshear Bond Strength of a Conventional Glass Ionomer Cement to Dentin</p>

“…9 Three nanoparticles that have previously been used in the field of dentistry are silver nanoparticles (SNPs), zinc oxide nanoparticles (ZNP), and titanium dioxide nanoparticles (TNPs). 6,10 The biocompatibility of the SNPs especially in lower concentrations has been previously confirmed. 11 Moreover, SNPs have demonstrated broad-spectrum and long-term antibacterial and antiviral activities even in low concentrations.…”

The Potential Translational Applications of Nanoparticles in Endodontics

“…Using a AgNPs-based irrigant as a final rinse almost doubled the fracture resistance of endodontically treated teeth compared to when NaOCl was used. 47 An imidazolium-based AgNPs solution was found to increase dentine roughness, which may have implications regarding the adhesion of obturation and restorative materials to root canal walls. 48 AgNPs-based irrigants did not negatively interfere with the hardness and elastic modulus of dentine 49 or the bond strength and interface permeability of resin-bonded glass-fibre posts.…”

“… 36 Overall, it appeared that a number of studies investigating AgNPs in the context of root canal irrigation provided partial characterization and mainly stated the particle size, concentration and, if the nanoparticles were outsourced, the manufacturing companies. 37 , 39–42 , 44 , 47 , 49–51 , 54 , 56 Regardless of the source of nanoparticles, whether they may be purchased from third parties or synthesized by the researchers, declaring the relevant physicochemical properties can help strengthen the scientific value of future studies on nanoparticle applications in endodontics. 7 …”

“… 42 Its use as a final irrigant resulted in an approximately 400N greater mean fracture resistance of root canal treated teeth compared to when NaOCl was used. 47 On the other hand, another study reported the push-out bond strength of endodontic sealers was negatively affected following irrigation with a polymeric suspension containing AgNPs and ZnONPs, possibly due to the deposition of nanoparticles on the dentine surface which decreased sealer adhesion. 77 …”

“… 78 Using a titanium dioxide nanoparticle solution as a final rinse was found to result in double the mean fracture resistance of endodontically treated teeth compared to when NaOCl was used. 47 Iron oxide nanoparticles exhibited peroxidase-like activity when synthesized into an irrigating solution with hydrogen peroxide, resulting in antibiofilm and bactericidal activity against E. faecalis . 79 However, like AgNPs, metal and metal oxide nanoparticles may also possess a degree of cytotoxicity, hence risk assessment and biocompatibility studies are paramount before proceeding to in vivo research.…”