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A New Nano-Chitosan Irrigant with Superior Smear Layer Removal and Penetration

MetadataDetails
Publication Date2016-07-01
JournalDOAJ (DOAJ: Directory of Open Access Journals)
AuthorsM.Z. Kassaee, Shabnam Hosseini, S. Hossein Elahi, Behnam Bolhari
InstitutionsArak University of Technology, Tarbiat Modares University
Citations12
AnalysisFull AI Review Included

Technical Documentation & Analysis: Nano-Chitosan Irrigant Wettability Study

Section titled “Technical Documentation & Analysis: Nano-Chitosan Irrigant Wettability Study”

This documentation analyzes the research paper “A New Nano-Chitosan Irrigant with Superior Smear Layer Removal and Penetration” to identify key technical requirements and demonstrate how 6CCVD’s specialized MPCVD diamond materials can serve as enabling substrates for advanced surface science, biomedical research, and sensor development in this field.


This study successfully demonstrated that Nano-Chitosan (Nano-CS) is a highly effective endodontic irrigant, exhibiting superior wettability and smear layer removal compared to traditional agents like NaOCl and EDTA.

  • Core Achievement: Nano-CS achieved significantly lower sessile contact angles (down to 43.77°) on dentin compared to NaOCl (down to 49.08°) and regular Chitosan (down to 48.81%), indicating superior penetration and wettability.
  • Key Mechanism: The small particle size (nano-scale) enhances capillary penetration into the complex dentin structure, while its superb chelating ability ensures effective smear layer removal.
  • Surface Science Requirement: The methodology relies critically on precise sessile contact angle measurement, requiring highly controlled and reproducible substrate surfaces for fundamental analysis.
  • 6CCVD Value Proposition: While the study used dentin, 6CCVD provides Optical Grade Single Crystal Diamond (SCD) substrates (Ra < 1nm) which serve as the ideal, inert, ultra-smooth reference surface necessary to decouple surface chemistry effects from topographical heterogeneity inherent in biological samples.
  • Advanced Applications: The high wettability and biocompatibility of Nano-CS suggest potential integration with advanced diamond-based electrochemical sensors (Boron-Doped Diamond, BDD) for in situ monitoring of irrigant concentration and efficacy.

The following hard data points were extracted from the sessile contact angle measurements comparing Nano-CS to common endodontic irrigants.

ParameterValueUnitContext
Lowest Nano-CS Sessile Contact Angle43.77°Achieved at 17.0% concentration (v/v)
Lowest CHX Sessile Contact Angle27.69°Achieved at 2.0% concentration (v/v) (Highest penetration)
Lowest NaOCl Sessile Contact Angle49.08°Achieved at 6.0% concentration (v/v)
Lowest CS Sessile Contact Angle48.81°Achieved at 17.0% concentration (v/v)
Lowest EDTA Sessile Contact Angle48.32°Measured at 17.0% concentration (v/v)
Control Liquid Contact Angle72.00°MilliQ water (High surface tension/poor wetting)
Nano-CS Concentration Range Tested0.2 - 17.0% (v/v)Aqueous solutions in distilled water
Final Dentin Polishing Roughness0.05”mAl₂O₃ suspension used for final surface preparation
Nano-CS Antibacterial Potency53.14%Against Enterococcus faecium in 15 minutes

The experiment focused on synthesizing Nano-CS and precisely measuring the wettability of various irrigants on prepared dentin surfaces.

  1. Nano-CS Synthesis: Chitosan (100,000-300,000 Da) was dissolved in 2% acetic acid, followed by the addition of tripolyphosphate (TPP). The resulting Nano-CS was isolated via high-speed centrifugation, rinsed, and freeze-dried.
  2. Substrate Preparation (Dentin): Extracted human maxillary molar roots were cut, embedded in araldite resin, and polished sequentially using abrasive papers (120/P120 up to 600/P1200 SiC) and then felted with diamond and 0.05 ”m Al₂O₃ suspension.
  3. Solution Preparation: Aqueous solutions of Nano-CS, CS, NaOCl, CHX, and EDTA were prepared across a wide concentration range (0.2% to 17.0% v/v or wt/wt).
  4. Contact Angle Measurement: A 1.00 ”l droplet of each solution was placed on the coronal root dentin. The sessile contact angle was measured using a camera setup and analyzed via Image J and AutoCAD 2014 software.
  5. Wettability Assessment: Penetration was assessed as an inverse function of the sessile contact angle; lower angles indicate better wetting and higher penetration.

The fundamental surface science explored in this paper—specifically the relationship between surface energy, wettability, and penetration—requires highly controlled substrates. 6CCVD specializes in providing the world’s most stable, inert, and ultra-smooth materials, enabling researchers to isolate variables and achieve reproducible results beyond the limitations of biological substrates like dentin.

To replicate or extend the fundamental surface energy measurements described in this research, 6CCVD recommends the following materials:

6CCVD MaterialRecommended GradeApplication Relevance
Single Crystal Diamond (SCD)Optical Grade (Type IIa)Ideal reference substrate for fundamental wettability studies. SCD is chemically inert, non-porous, and offers the lowest achievable surface roughness (Ra < 1 nm), allowing researchers to decouple the effects of surface chemistry from topography.
Polycrystalline Diamond (PCD)High Purity GradeSuitable for large-area testing arrays or flow cells where chemical inertness is critical, but the highest optical clarity is not required. Available in large dimensions (up to 125mm).
Boron-Doped Diamond (BDD)Heavy Doping (Electrochemical)Enabling material for next-generation biomedical sensors. BDD electrodes can be integrated into microfluidic devices to monitor the concentration, degradation, or electrochemical activity of Nano-CS irrigants in situ during endodontic procedures.

The precision required for contact angle measurement demands highly specific substrate characteristics. 6CCVD’s advanced fabrication capabilities directly address these needs:

  • Ultra-Low Roughness Polishing: We offer SCD polishing down to Ra < 1 nm and inch-size PCD polishing down to Ra < 5 nm. This level of surface quality is essential for minimizing topographical interference (capillary penetration effects) and achieving true thermodynamic equilibrium contact angles, which is a known challenge in the paper (Section: Discussions).
  • Custom Dimensions: For developing large-scale testing platforms or microfluidic chips, 6CCVD provides custom plates and wafers up to 125 mm in diameter (PCD) and custom thicknesses for SCD (0.1 ”m to 500 ”m).
  • Precision Metalization: If the research extends to integrating heating elements or sensor contacts, 6CCVD offers in-house metalization services, including Ti/Pt/Au, W, Pd, and Cu layers, deposited directly onto the diamond surface.

6CCVD’s in-house PhD team specializes in diamond surface science and electrochemical applications. We offer authoritative professional support for projects involving:

  • Surface Energy Analysis: Assisting researchers in selecting the optimal diamond substrate (SCD vs. PCD) and polishing specification to achieve reproducible surface energy measurements for biomedical liquids.
  • Biocompatibility Studies: Providing high-purity diamond materials for advanced in vitro testing, ensuring material inertness does not interfere with the observed biological or chemical effects of agents like Nano-CS.
  • Sensor Integration: Consulting on the design and fabrication of BDD electrodes for electrochemical sensing of active agents (like chlorhexidine or Nano-CS derivatives) in complex biological environments.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Our primary objective was to measure root canal penetrations of aqueous antibacterial nano-chitosan (Nano-CS), for the first time. The second objective was to compare and contrast such penetrations to those of chitosan (CS) itself, as well as sodium hypochlorite (NaOCl), chlorhexidine (CHX) and ethylenediamintetraacetic acid (EDTA), at the routinely used concentrations. Molar roots were split longitudinally by a rotary diamond saw. Nano-CS was made by dissolving CS in acetic acid and adding tripolyphosphate (TPP), followed by a freeze-drying process. Dentin penetrations are estimated through measurements of sessile contact angles. Penetrations of the probed irrigants were assessed as inverse functions of their sessile contact angles. Accordingly, all Nano-CS solutions showed smaller sessile angles compared to those of NaOCl, CS, and EDTA samples. Hence, Nano-CS appeared to be a superior irrigant for demonstrating a higher penetration than the latter three. It fell only behind CHX, yet, the superb chelating ability of Nano-CS enabled it to remove smear layer to a larger extend than all of our other irrigants including CHX. Nano-CS could be considered as a new irrigant. Higher penetration was its main advantage over CS, and commercial NaOCl, and EDTA. This was verified by the smaller sessile contact angle of Nano-CS. Anticipated chelating effect of Nano-CS could anchor more efficient removal of smear layer. This was another advantage of Nano-CS over other irrigants including CHX. Other advantages of Nano-CS included its reported biocompatibility, biodegradability and antibacterial effects. Commercialization of Nano-CS was deemed in the near horizon.