Cleaning Paste Research Articles

Effects of pre-cementation cleaning protocols on bond strength of indirect composite resin restorations contaminated with saliva.

Objective: Compare the effects of different pre-cementing cleaning protocols on adhesive bond strength (MPa) in indirect composite resin restorations contaminated with saliva. Materials and Methods: 110 tests bodies of indirect composite resin, divided into 2 groups: with no contamination (NC); with contamination (WC); distributed in 22 subgroups (n = 5) according to the Ultrasound (U) variables; Cleaning Paste (CP); Ethanol 96 ° (E), Application times: 5-20-30-180s. Five cylinders (1mm high x 0.7 Ø) of cement (Variolink Esthetic LC) per sample made on treated and light-cured surfaces (20s). After 24hrs / 37ºC + distilled water, they were subjected to the RUA test (0.5 mm / min) until fracture point in a universal test machine. Analyzed with one-way ANOVA and post hoc Tukey test (α = 0.05).Results: Contaminated CP30’’ was the protocol with the highest binding resistance (14.57 ± 1.01) (p <0.05). Conclusion: The gold standard technique - corresponding to ultrasonic washing - is unrecommended for cleaning indirect composite resin restoration, seen as there are other more effective protocols to eliminate surface contaminants. Cleaning paste and Ethanol in times of 20’’ or 30’’ are suggested.

Influence of different cleaning procedures on the shear bond strength of 10-methacryloyloxydecyl dihydrogen phosphate-containing self-adhesive resin cement to saliva contaminated zirconia.

Purpose To evaluate the effect of different cleaning methods on the shear bond strength (SBS) of a 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing self-adhesive resin cement to zirconia after saliva contamination.Methods Sixty zirconia specimens were randomly divided into four groups (n=15) according to treatment surface. Except for the control group, all samples were contaminated with saliva and were then rinsed with water-spray and air-dried. Subsequently, the specimens were either treated with a cleaning paste (CP), with argon plasma (AP), or did not undergo an additional cleaning process (WS). An MDP-containing self-adhesive resin cement was applied onto the ceramic surfaces. Specimens were stored in water (24 hours) followed by thermocycling (5°C to 55°C for 10.000 cycles). SBS tests were performed in a universal testing machine, and the results (MPa ± SD) were statistically analyzed using ANOVA and Bonferroni post-hoc test. Fractured surfaces were examined to identify the failure types using a stereomicroscopy and SEM.Results The surface cleaning treatment (p<0.05) significantly affected the results. The highest SBS values were observed in the control group (12.16 ± 1.22 MPa) and were statistically comparable to values for the CP group (11.38 ± 1.65 MPa). The AP group (9.17 ± 1.06 MPa) showed significantly higher bond strength than the WS group (6.95 ± 1.20 MPa), but it showed significantly lower strength than the control and CP groups.Conclusions The CP application was the most effective method in removing saliva contamination. The AP treatment could not restore the SBS to the same level as uncontaminated specimens.

Effect of Different Cleaning Regimens on the Adhesion of Resin to Saliva‐Contaminated Ceramics

The aim of this study was to evaluate the influence of different cleaning regimens on the microshear bond strength (μSBS) of three different all-ceramic surfaces after saliva contamination. Cubic ceramic specimens (3 × 3 × 3 mm(3) ) were prepared from three types of ceramics: zirconium dioxide (Z), leucite-reinforced glass ceramic (E), lithium disilicate glass ceramic (EX; n = 12/subgroup). A total of 144 composite resin cylinders (diameter: 1 mm, height: 3 mm) were prepared. Three human-saliva-contaminated surfaces of ceramic specimens were cleaned with either water spray (WS), with 0.5% sodium hypochlorite solution (HC), or with a cleaning paste (CP). Control surface (C) was not contaminated or cleaned. Composite cylinders were bonded to each surface with a resin luting cement. All specimens were stored at 37°C in deionized water until fracture testing. μSBS tests were performed in a universal testing machine (0.5 mm/min), and the results (MPa ± SD) were statistically analyzed (two-way ANOVA, Bonferroni a = 0.05). Fractured surfaces were analyzed to identify the failure types using an optical microscope at 50× magnification. Two representative specimens from all groups were examined with scanning electron microscopy. μSBS test results were significantly affected by the saliva cleaning regimens (p = 0.01) and the ceramic types (p = 0.03). The interaction terms between the ceramic type and saliva cleaning regimen were also significant (p < 0.05). There were no significant differences among the μSBS values (MPa ± SD) for the Z group (C = 17.5 ± 8.8; WS = 16.0 ± 4.9; HC = 17.6 ± 5.8; CP = 16.6 ± 7.5; p > 0.05). In the EX group, C resulted in significantly higher μSBS values (32.6 ± 7.4) than CP (17.4 ± 8.9), WS (15.6 ± 7.3), and HC (14.3 ± 4.5) (p < 0.05); however, C (20.4 ± 7.1) and HC (19.2 ± 7.5) showed higher μSBS values than CP (13.8 ± 4.8) and WS (10.9 ± 5.7) in the E group. Some cohesive failures within the luting resin were observed in the E and EX groups, whereas only adhesive failures were seen in zirconia groups for all surface treatments. Different ceramic surface cleaning regimens after saliva contamination of the zirconium dioxide revealed μSBS similar to the control group, whereas all surface cleaning regimens tested significantly decreased the bond strength values in the lithium disilicate glass ceramic. The leucite-reinforced glass-ceramic group benefited from 0.5% sodium hypochlorite solution cleaning with increased bond strengths. Adhesive cementation of zirconia presents a clinically challenging protocol, and the cementation surface contamination of the zirconia restorations and the inadequate removal of the contaminants increase the risk of failure, as for all ceramic types. This study demonstrated that surface cleaning regimens should be applied according to different ceramic properties.