Influence of sodium hypochlorite on fracture properties and corrosion of ProTaper Rotary instruments

Berutti, Elio; Angelini, Emma Paola Maria Virginia; Rigolone, Mauro; Migliaretti, Giuseppe; Pasqualini, Damiano

doi:10.1111/j.1365-2591.2006.01134.x

Cited by 106 publications

(99 citation statements)

References 39 publications

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“…Sodium hypochlorite is an oxidative solution which breaks down polymer chains that cause structural deformations to a wide range of materials (Berutti et al, 2006;Yamauti et al, 2003). Some studies have confirmed the capacity of this substance to cause alterations during the process of disinfecting gutta-percha cones, especially when the solution is used at concentrations higher than 2.5% (Valois et al, 2005a,b).…”

Section: Introductionmentioning

confidence: 95%

SEM evaluation of thermoplastic endodontic materials alterations after disinfection: A new experimental model

Grecca

Porto

Fontanella

et al. 2010

Microscopy Res & Technique

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This study assessed a new experimental model to analyze the effects of sodium hypochlorite solution 2.5% for 10 min and chlorhexidine 2% for 15 s on cones surface alterations. Twenty five gutta-percha and 25 thermoplastic synthetic polymer-based cones had their last 1 mm from the tapered end examined by scanning electron microscopy (SEM) before and after being exposed to the disinfectant solutions. To allow the surfaces to be compared, the samples were not metalized, a voltage of 1 kV was used and the images were captured within standardized angles. The samples were immersed on the test solutions. The comparison of the alterations of the cones was performed using the software program Adobe Photoshop CS. A measurement was taken of the standard deviations of the pixel intensity in this area, higher standard deviations represent more irregular areas. Differences in standard deviation before and after disinfection for each cone were compared between groups by means of analysis of variance supplemented by the Tukey test. Gutta-percha cones showed higher standard deviations than Resilon cones (P < 0.001). In the gutta-percha cones, sodium hypochlorite generated more irregular areas than chlorhexidine and the control group (P < 0.001). The present study has demonstrated the feasibility of using a modified SEM method. This opens opportunities to the use of new and precise tools for evaluating a sample in different moments.

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Section: Introductionmentioning

confidence: 95%

SEM evaluation of thermoplastic endodontic materials alterations after disinfection: A new experimental model

Grecca

Porto

Fontanella

et al. 2010

Microscopy Res & Technique

View full text Add to dashboard Cite

show abstract

“…However, the potential for fracture of these instruments is still a main concern associated with their use 2,3) . Root canal curvature 4) , instrument geometry 5,6) , working speed 7) , the use of irrigant 8) , torque and sterilization procedures 9,10) , metal surface treatments 11) , heat treatment 12) , metallurgic characterization of the NiTi alloys 13) , and repeated clinical use 14,15) are factors that might enhance instrument fatigue. Moreover, these factors show different effects on the lifespans of different NiTi instrument systems.…”

Section: Introductionmentioning

confidence: 99%

Deflecting load of nickel titanium rotary instruments during cyclic fatigue

et al. 2012

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The dispersion of the lifetime of NiTi instruments, and their deflecting load (DL) changes during cyclic fatigue were investigated. A total of 120 ProFile NiTi rotary instruments were tested using a specially designed cyclic fatigue testing apparatus with three pins. Using these pins, the instrument was bent and rotated at 300 rpm to fracture. DL was recorded using a load cell attached to the central pin. For each sample, the working time was converted to number of cycles to fracture (NCF) and the mean DL (DLm) was calculated. The averages of NCF and DLm of 120 samples were 584.3±180.5 cycles and 6.44±0.91 N, respectively. All samples showed a sequential decrease in DL during rotation. Based on the present study, it is impossible to estimate the lifetime of a NiTi instrument from NCF. Thus, the change in DL could be an alternative criterion to determine the remaining lifetime.

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“…A recent study showed that fi les immersed in 5.25 % of sodium hypochlorite had significantly less resistance to fracture when they underwent cyclic fatigue. 49 …”

Section: Irrigation and Irrigantsmentioning

confidence: 99%