Micro Push-Out Bond Strength of Resin Composite to Dentin in Primary Dentition Using Three Universal Adhesives with Different pH: An In Vitro Study

Abstract

To evaluate the bond strength of different universal adhesives on deciduous tooth dentineand their relationship with the composition and potential of hydrogen (pH). Methods: An in vitromicro push-out test on 150 samples (n = 50) per group per adhesive, namely, Adhese Universal(ADH; Ivoclar Vivadent), Futurabond U (FUT; Voco GmbH) (Test), and Scotchbond Universal withpre-conditioning (SCO; 3M) (Control), to record bond strength (BS) and type of adhesive failure.Results: The results of the different adhesives (megapascals (MPa)) varied, showing no statisticalsignificance. The corresponding averages are in MPa: ADH, 13.66 2.81; FUT, 14.48 2.88; SCO,14.98 3.96. Additionally, the frequency of type of failure was as follows: mixed (60.7%), adhesive(27.3%), and cohesive (12%). Conclusions: SCO, with a pH of 2.7, showed greater resistance tofracture, while FUT, with a pH of 2.3 and no pre-conditioning, approached the same values, being aone-step adhesive. No relationship was found between failure and type of adhesive.

Influence of 2% Chlorhexidine on the Bond Strength of Three Adhesive Systems on Primary Molars: An In Vitro Study

“…There are very few studies carried out using the novel adhesion test proposed in this study; only a single study carried out in 2021 by Del Rio and collaborators [23] coincides in the analysis of adhesion strength with this same resistance test, though it was disparate in terms of the non-use of CHX during the adhesive process in deciduous dentition and the higher percentage of orthophosphoric acid used in acid etching. If we compare the data provided by these authors [23] for universal adhesives with self-etch strategies, with a value of 13.66 ± 2.81 MPa, versus the values of our study for this same category of adhesive of 17.28 ± 9.48 MPa when applied without CHX pretreatment and 16.15 ± 8.53 MPa on average both when CHX was applied and when CHX was not applied, we do not observe large discrepancies; similarity also in the data with respect to universal adhesives with total-etch strategies with the value of 14.98 ± 3.96 MPa similar to 15.28 ± 4.45 MPa when applied without CHX pretreatment and 16.34 ± 4.90 MPa on average both when CHX was applied and when not applied, provided by the present study. Regarding self-etching adhesives, we also show the similarity of our results with respect to the study carried out in 2021, which provided a BS value of 14.48 ± 2.89 MPa, consistent with 20.41 ± 7.05 MPa when this type of adhesive was applied without CHX and 20.27 ± 5.89 MPa on average both when CHX was applied and when it was not applied, in our study.…”

“…Each disc was fixed to the bottom of the micropush-out device by placing the restoration in the hole of the plate. A cylindrical punch (0.8 mm diameter) made of steel from a universal testing machine (Hounsfield test equipment ® HTE, Croydon, UK), exerted force in the crown-apical direction until failure load (expressed in newtons (N)) was reached, with a speed of 0.5 mm/min [23]. Failure load values obtained were registered using the advanced testing software Metrotest (TechLab Systems, Itasca, IL, USA): software for control and management of the data in a single piece of test equipment.…”