Effect of blood contamination and decontamination protocols on acetone-based and ethanol-based total etch adhesive systems

Effect of contamination and decontamination methods on the bond strength of adhesive systems to dentin: A systematic review

INTRODUCTION

In a suitable condition, it is important to perform any dental restorative procedure using an operatory field isolated. Then, the aim of this study was to compare the bond strength of composite restorations to dentin affected by any contamination agent through a systematic review.

METHODS

This systematic review was performed following the PRISMA 2020 guidelines. The literature search was conducted until September 2022 by scanning the following databases: Embase, PubMed, Scielo, Scopus, and Web of Science. Manuscripts evaluated the bond strength of resin-based materials to permanent human dentin contaminated with blood or saliva were selected for full-text review. The risk of bias was assessed by the RoBDEMAT tool.

RESULTS

A total of 3750 papers resulted from the search from all databases. After the full-text reading, a total of 62 articles remained for the qualitative analysis. The contamination agents used were blood, saliva, and hemostatic agents. A great variety of protocols were used to contaminate the dentin surface, and the contamination process occurred in several steps of the bonding process, including before and after the etching process, after the primer application and after the adhesive application. Also, several decontamination procedures were tested, including reapplication of the etching material, rinsing with water, chlorhexidine or sodium hypochlorite and reapplication of the adhesive system.

CONCLUSION

Any contamination with blood or saliva impaired the bond strength of resin-based materials to dentin. Decontamination procedures including water-spray and reapplication of the bonding system could revert the impairment produced by the saliva or blood contamination. The use of hemostatic agents as a method of blood decontamination is not recommended.

CLINICAL SIGNIFICANCE

Clinicians should avoid contamination during a bonding procedure, otherwise, a reduction in the bond quality is expected.

Universal adhesive application to contaminated/non-contaminated dentin with three different protocols: An in vitro shear bond strength and SEM analysis

This study aimed to comparatively evaluate the shear bond strength (SBS) of a universal adhesive to contaminated/non-contaminated dentin when applied with three different protocols. One-hundred-eighty dentin samples were divided randomly into 12 groups (n=15). The groups were created by combining four dentin contamination conditions (non-contaminated or contaminated with blood, hemostatic, or blood+hemostatic) with three application protocols for Single Bond Universal (no-preconditioning or preconditioning with the 35% phosphoric or 1% gallic acid). Following thermal cycling, the SBS test was performed. Data were analyzed using two-way-ANOVA and Tukey's HSD (p<0.05). Dentin surfaces subjected to phosphoric acid, gallic acid, or hemostatic were examined using scanning electron microscope (SEM) analysis. SBS results were influenced by both the dentin contamination (p<0.001) and application protocol (p<0.001). A significant interaction was found between the two factors (p=0.005). The highest bonding performance to contaminated dentin -at all contamination conditions- was achieved with the gallic acid preconditioning.

Bond strengths of three-step etch-and-rinse adhesives to silane contaminated dentin

This study aimed to evaluate the effect of silane coupling agent contamination on the microtensile bond strength (µTBS) of 3-step etch-and-rinse adhesives on dentin. Flat occlusal dentin surfaces were prepared and randomly divided into 8 groups (n=20) based on the tested adhesives; Scotchbond Multi-purpose or Optibond FL, with contamination of an experimental silane (2 vol% of 3-m ethacryloxypropyltrimethoxysilane at pH 4.5) before acid-etching, after-etching or after-priming; while the groups without silane contamination served as controls. µTBS data were analyzed by two-way ANOVA and Tukey's HSD tests at a significance level of 0.05. Additional specimens of contaminated dentin were used to analyze changes in the organic molecules by Fourier transform infrared spectroscopy (FTIR). Silane contamination before acid-etching did not significantly change µTBS (p>0.05), but contamination after-etching and after-priming significantly decreased µTBS of both adhesives (p<0.05). Silane contamination had an adverse effect on the dentin bond strength of 3-step etch-and-rinse adhesives especially after-priming.

Comparative evaluation of the effect of decontamination protocol on the shear bond strength of eighth generation bonding agent to contaminated dentin: an in vitro study

Introduction

This in vitro study aims to evaluate and compare the effect of decontamination protocol - based on sodium hypochlorite - NaOCl, as a decontaminating agent, followed by the application of a collagen cross-linking agent like sodium ascorbate or Proanthocyanidin on the shear bond strength of eighth generation bonding agent to contaminated dentin (saliva, blood and blood followed by hemostatic agent).

Methods

The buccal surfaces of extracted premolars were flattened to expose the dentine. The teeth were then randomly divided into 3 groups based on the contaminant used (saliva, blood and blood followed by hemostatic agent). Decontamination protocol was carried out with sodium hypochlorite followed by application of either of the two collagen cross-linking agents (sodium ascorbate/proanthocyanidin) in each group. FuturaBond DC (eighth generation) bonding agent was used to bond composite to dentin surfaces which was subjected to shear bond strength testing. Data was analyzed by one-way ANOVA and Tukey test.

Results

All the groups (contaminated with saliva, blood, or hemostatic agent) showed a decrease in shear bond strength of composite resin to dentin. The shear bond strength of composite resin to dentin was least affected by contamination with saliva followed by contamination with blood and was most affected by contamination with a hemostatic agent.

The decontamination protocol carried out showed that the combination of NaOCl and Proanthocyanidin improved the shear bond strength of composite to dentin significantly more than the combination of NaOCl and sodium ascorbate or of sodium hypochlorite used alone.

Penetration of Different Impression Materials into Exposed Dentinal Tubules during the Impression Procedure

Adhesive restorations have been shown to guarantee excellent performance and longevity, although this comes with some disadvantages. Among these, the vulnerability of dentine to different agents has been widely evaluated. The aim of this study was to evaluate the possible penetration of impression materials into freshly cut dentine. Dentine from 27 teeth was impressed with polyether (Impregum Penta L) (nine teeth) and with polyvinyl siloxane (Aquasil Ultra LV) (nine teeth). The surface of nine teeth after the impressions were used as the control. Specifically, the extroflections caused by the imprinting of the dentinal tubules on the impression material, the so-called impression tags, were measured. Furthermore, the presence of the material inside the tubules was examined. Scanning electron microscopy analysis showed material tags for all of the experimental groups. The mean lengths (±SD) were 22.6 (±11.0) µm for polyether, 21.8 (±12.8) µm for polyvinyl siloxane and 11.3 (±7.0) µm for the tooth control, with mean diameters (±SD) of 2.8 (±0.5), 2.4 (±0.7) and 3.1 (±0.7) µm, respectively. Fractal analysis showed fractal dimensions of 1.78 (±0.03), 1.77 (±0.03) and 1.71 (±0.03), respectively. These data demonstrated that the impression materials can remain inside the dentinal tubules, which can adversely affect the adhesive procedures.

Effect of Decontamination Treatments on Micro-Shear Bond Strength between Blood-Saliva-Contaminated Post-Etched Dentin Substrate and Composite Resin

Blood–saliva contamination negatively affects the bonding potential of adhesive agents. The study aimed to assess the effect of various cleaning protocols on micro-shear bond strength (μSBS) between blood–saliva-contaminated post-etched dentin and composite resin in total-etch and self-etch adhesives. The cleaning methods tested were water rinsing, 37.5% phosphoric acid (H3PO4) re-etching, 6% sodium hypochlorite (NaoCl), 2% chlorhexidine gluconate (CXG), isopropyl alcohol (IPA), and pumice. Nono-hybrid composite cylinders with a 3-mm diameter and 2-mm height were directly cured over the dentin substrate, stored for 24 h, and subjected to 12,000 thermocycles. The shear force was exerted with a 200-μm knife-edged chisel-shaped head from a universal testing machine. The type of failure was assessed with stereomicroscope magnified images. The obtained data were evaluated by Kruskal–Wallis and Mann–Whitney U post-hoc tests. Water-rinsed contaminated dentin surfaces showed substantially reduced μSBS in the total etch from 25.93 to 20.29 Mpa and the corresponding values for the one-step self-etch adhesive were 10.10 to 8.8. Re-etching with 37.5% H3Po4 resulted in a recovery of bonding potential in both total-etch (24.58 Mpa) and self-etch adhesive (9.23 Mpa). Alternately, NaoCl and pumice cleaning showed promising results for the total-etch (23.51 Mpa) and self-etch (7.79 Mpa).

Effect of various bleaching treatments on shear bond strength of different universal adhesives and application modes

Objectives

The aim of this in vitro study was to evaluate the bond strength of 2 universal adhesives used in different application modes to bleached enamel.

Materials and Methods

Extracted 160 sound human incisors were used for the study. Teeth were divided into 4 treatment groups: No treatment, 35% hydrogen peroxide, 16% carbamid peroxide, 7.5% carbamid peroxide. After bleaching treatments, groups were divided into subgroups according to the adhesive systems used and application modes (n = 10): 1) Single Bond Universal, etch and rinse mode; 2) Single Bond Universal, self-etch mode; 3) Gluma Universal, etch and rinse mode; 4) Gluma Universal, self-etch mode. After adhesive procedures nanohybrid composite resin cylinders were bonded to the enamel surfaces. All specimens were subjected to shear bond strength (SBS) test after thermocycling. Data were analyzed using a 3-way analysis of variance (ANOVA) and Tukey post hoc test.

Results

No significant difference were found among bleaching groups (35% hydrogen peroxide, 16% carbamid peroxide, 7.5% carbamid peroxide, and no treatment groups) in the mean SBS values. There was also no difference in SBS values between Single Bond Universal and Gluma Universal at same application modes, whereas self-etch mode showed significantly lower SBS values than etch and rinse mode (p < 0.05).

Conclusions

The bonding performance of the universal adhesives was enhanced with the etch and rinse mode application to bleached enamel and non-bleached enamel.