Nanoleakage for Self-Adhesive Resin Cements used in Bonding CAD/CAD Ceramic Material to Dentin

Abstract

Objectives:To determine nanoleakage of CAD/CAM ceramic blocks bonded to dentin with self-adhesive resin cement.Methods:Eighteen sound extracted human molars were sterilized and sectioned into 3 mm-thick dentin sections. Trilux Cerec Vitablocks (Vita) were also sectioned into 3 mm sections, surface-treated using 5% hydrofluoric acid-etchant, and then coated with silane primer (Vita). Trilux and dentin sections were cemented together by means of three resin cements: Rely-X Unicem (3M/ESPE), BisCem (Bisco), and Calibra (Dentsply), according to manufacturers’ recommendations. Calibra was used in conjunction with Prime/Bond-NT adhesive (Dentsply), while the other two are self-adhesive. The bonded specimens were stored for 24h in distilled water at 37°C. Specimens were vertically sectioned into 1 mm-thick slabs, yielding up to six per specimen. Two central slabs were randomly chosen from each specimen making up the cement groups (n=12). Each group was subdivided into two subgroups (n=6), a control and a thermocycled subgroup (5–55°C) for 500 cycles. Slabs were coated with nail polish up to 1 mm from the interface, immersed in a 50% silver nitrate solution for 24h, and tested for nanoleakage using Quanta Environmental SEM and EDAX. Data were statistically analyzed using two-way ANOVA and Tukey’s post-hoc tests.Results:Rely-X Unicem and Calibra groups demonstrated no significant difference in the percentage of silver penetration, while the BisCem group revealed a significantly higher percentage (P≤.05). Thermocycling (500 cycles) did not have a statistically significant effect on the percentage of silver penetration (P>.05).Conclusions:One self-adhesive-resin cement demonstrated a similar sealing ability when compared with a standard resin cement. Thermo-cycling did not significantly increase dye penetration under the test conditions.

Fracture Strength and Nanoleakage of Weakened Roots Reconstructed Using Relined Glass Fiber–Reinforced Dowels Combined with a Novel Prefabricated Core System

“…For years, “extent of microleakage” was used to evaluate the sealing ability of cemented restorations; however, in 1994, Sano et al described a new pattern of microleakage that occurred in the absence of gaps and which resulted from subsurface porosity of demineralized dentin. This form of leakage was detected on a microscopic, as opposed to a macroscopic, level and was thus referred to as “nanoleakage.”…”

“…This form of leakage was detected on a microscopic, as opposed to a macroscopic, level and was thus referred to as "nanoleakage." 23 Nanoleakage is a leakage pattern occurring within the nanometer-sized spaces within the hybrid layer and the adhesive/resin interface. 24 According to Abo El Naga, nanoleakage "is an important indicator for judging the material's sealing ability and quality of the hybrid layer, which in turn affects the material's longevity.…”

Cervical and incisal marginal discrepancy in ceramic laminate veneering materials: A SEM analysis

“…Therefore, autoradiography is still a qualitative and a sensitive technique for determining leakage. [ 20 ]…”

Does the use of a novel self-adhesive flowable composite reduce nanoleakage?

“…Nanoleakage analysis results were conveyed in terms of silver deposition percentages at the three representing points, then the extent of silver penetration was calculated to work out the total silver nitrate penetration of the tested interface, which represents the most commonly used material for nanoleakage, owing to its easy migration within the interface zone as a result of its nano-scaled diameter molecule (0.059 nm). 18 , 48 Also, it induces a contrast that gives a clear electron microscopic picture presenting the degree of penetration into the interface. Finally it has the potential to prevent any further penetration that might occur while preparing a specimen, due to its immobilization potentiality.…”

“…For many years, the longevity of bonded restorations has been expressed in terms of microleakage extent measurements. 18 This leakage around resin composite restoration decreases restoration longevity, as it might lead to postoperative sensitivity, marginal discoloration, secondary caries, pulpal inflammation, and eventually partial or complete loss of that restoration. 19 , 20 However, the latter may be due to either imperfections or improper cavity preparation.…”