Duration of Immersion and Type of Immersion Solution Distort the Outcome of Push-Out Bond Strength Testing Protocols

Abstract

This study aimed to investigate the influence of immersion duration and the type of immersion solution on the outcome of push-out bond strength (POBS) tests. Root canals of 120 straight single-rooted teeth were instrumented to a diameter of 1.5 mm and irrigated with 5 mL of 3% NaOCl. Four horizontal slices with a thickness of 1 mm were cut, representing the mid-portion of the root. The specimens (n = 480) were irrigated with 17% ethylenediaminetetraacetic acid(EDTA) for 60 seconds, then twice with distilled water (DW) for 30 s each. The canals were filled with either AH Plus (Dentsply Sirona, Konstanz, Germany) or BioRoot RCS (Septodont, St. Maur-des-Fossés, France) (n = 240). Separated into four groups per type of sealer (n = 60), the specimens were incubated at 37 °C covered with gauze moistened in DW or phosphate-buffered saline (PBS) for either one or eight weeks. Dislodgement resistance was measured and POBS was calculated. Statistical analysis was performed using the analysis of variance (ANOVA) test and the Student–Newman–Keuls test (p = 0.05). AH Plus showed higher POBS when stored in PBS compared to DW, irrespective of the incubation period (p < 0.05). BioRoot RCS displayed higher POBS when stored in DW compared to PBS after eight weeks of incubation (p < 0.05). No difference was found after one week of incubation (p > 0.05). Irrespective of the sealer or the immersion solution, POBS decreased from one week to eight weeks (p < 0.05). Mixed failure modes were found in all groups irrespective of sealer, immersion medium, or immersion period. POBS decreased after a longer incubation time in both immersion solutions. Duration of immersion and the type of immersion solution had a significant impact on the outcome of the POBS testing protocol.

Influence of long -term thermal cycling and masticatory loading simulation on bond strength of roots filled with epoxy resin and calcium silicate based sealers

“…Hence, because of the different methodologies used in the various studies, a direct comparison with other POBS studies was difficult. Nevertheless, the POBS of AH Plus sealer was primarily better than that of BioRoot RCS, which was consistent with POBS after aging reported previously [ 14 – 16 , 28 ]. The improved bonding might be related to the covalent connections between the amino groups of the dentinal collagen and epoxy resin [ 29 ] so that the resulting polymer is heavily cross-linked and is thus rigid and strong [ 30 ] compared with the interaction of calcium silicates to dentin.…”

Short and Long-Term Solubility, Alkalizing Effect, and Thermal Persistence of Premixed Calcium Silicate-Based Sealers: AH Plus Bioceramic Sealer vs. Total Fill BC Sealer

“…In previous studies evidence was found that the solubility, alkalizing potential, and bond strength of calcium silicate-based sealers depend on the immersion solution [ 4 , 15 ]. It was assumed that the precipitation of hydroxy apatite on the surface of calcium silicate-based materials after contact to phosphate concludes in a decrease of solubility [ 4 ].…”

Influence of the use of chelating agents as final irrigant on the push‐out bond strength of epoxy resin‐based root canal sealers: A systematic review

“…Even minor differences in the testing protocol might lead to a distortion of results, and duration of immersion and type of immersion solution displayed a significant impact on the push‐out bond strength (13). An alternative to obtaining clinically relevant results from push‐out bond strength tests is to use immersion solutions simulating body fluids as phosphate‐buffered saline (PBS) (13).…”

“…Donnermeyer et al (2019) evaluated the effect of the type and duration of immersion on the results of the push-out bond strength protocols and showed that the push-out bond strength of AH Plus was significantly higher than that of BioRoot RCS when comparing the same immersion solutions and immersion periods, and showed that the percentage of adhesive failure modes has increased while increasing sample storage time (13). Even minor differences in the testing protocol might lead to a distortion of results, and duration of immersion and type of immersion solution displayed a significant impact on the push-out bond strength (13). An alternative to obtaining clinically relevant results from push-out bond strength tests is to use immersion solutions simulating body fluids as phosphate-buffered saline (PBS) (13).…”

“…It has been shown that the final irrigation solution relevantly influences the dislodgment resistance of AH Plus in laboratory (13), becoming an important issue from a clinical point of view. Although this parameter cannot be clinically measured, it is important to collect the best scientific evidence about the actual impact of root canal final irrigation protocols using chelating agents on the epoxy-based root canal sealers, even if only laboratory studies could be conducted with this purpose.…”