Ultrasonic Irrigation In Endodontics

Ultrasonic Irrigation

Ultrasonic irrigation has shown to clean the root canals or eliminate bacteria from the walls better than conventional methods. The use of ultrasonics causes a continuous flow of an irritant in the canal, thus preventing the accumulation of debris in the canal.

Mechanism of Action:

When a small file is placed in the canal and ultrasonic activation is given, ultrasonic energy passes through the irrigating solution and exerts its “acoustic streaming or scrubbing” effect on the canal wall. This mechanical energy warms the irrigant (sodium hypochlorite) and dislodges debris from the canal. The combination of activation and heating of irrigating solution is adjunct in cleaning the root canal.

Read And Learn More: Endodontics Notes

Ultrasonic Irrigation Advantages:

• It cleans the root canal walls better than conventional ones
• It removes the smear layer efficiently
• It dislodges the debris from the canal better due to the acoustic effect

Ultrasonic Irrigation Disadvantages:

• Ultrasonic preparation of the canal is found to be unpredictable
• It can lead to excessive cutting of canal walls and may damage the finished preparation

Newer Irrigating Solutions

Electrochemically Activated Solution:

• It is produced from tap water and low-concentrated salt solutions
• The principle of electrochemically activated (ECA) is transferring liquid into the metastable state via electrochemical unipolar action using a reactor
• Electrochemical treatment in anode and cathode chambers results in the synthesis of two types of solutions, that is, anolyte (produced in anode chamber) and catholyte (produced in cathode chamber)
• Anolyte solution has also been termed as super oxidized water or oxidative potential water. The pH of an anolyte can be acidic (anolyte), neutral (anolyte neutral), or alkaline (anolyte neutral cathodic). Earlier, acidic anolyte was used but now neutral and alkaline solutions are preferred

Advantages of electrochemically activated solution:

• Nontoxic to biological tissues
• Less or no allergic reaction
• Effctive with a wide range of microbial spectra
• Combined use of NaOCl and ECA solution has been shown to remove the smear layer

Ozonated Water Irrigation:

• Ozone is an unstable gas which can oxidize any biological unit. Ozonated water is shown to be a powerful antimicrobial agent against bacteria, fungi, protozoa, and viruses

Advantages of ozonated water:

• Its potency
• Ease of handling
• Lack of mutagenicity
• Rapid microbial effects

Ruddle’s Solution:

It is of 17% EDTA, 5% NaOCl and hypaque.

Mechanism of Action:

• Hypaque is an aqueous radiopaque solution of iodide salts, namely, diatrizoate and sodium iodine
• The use of EDTA lowers the surface tension and allows better penetration of sodium hypochlorite
• The solvent action of sodium hypochlorite clears the contents of the root canal system and thus enables hypaque component to flow into every nook and corner of the canal system such as fracture, perforation, missed canals, and defective restoration

Ruddle’s Solution Uses:

• Useful for visualization of root canal anatomy, missed canal, perforation, etc.
• Helps in the diagnosis of internal resorption, its size, and site
• Helps in the visualization of blockage, perforation, ledge, and canal transportation
• Helps in the management of iatrogenic errors

Photoactivated Disinfection:

Photoactivated disinfection (PAD) is based on the concept that nontoxic photosensitizers can be localized in certain tissues and activated by light of the suitable wavelength to produce oxygen and free radicals which are cytotoxic to cells of the target tissue. Methylene blue, toluidine blue, and chlorine p6 are commonly used photosensitizers which release oxygen when exposed to the low-power laser.

Advantages of PAD:

• Most effctive antimicrobial agent
• Effectively kills Gram-negative, Gram-positive, aerobic and anaerobic bacteria
• Overcomes the problems of antibiotic resistance
• Kills bacteria present in complex biofilm such as sub-gingival plaque which is typically resistant to the action of antimicrobial agents
• Does not pose any thermal risk due to the low power of the PAD laser
• Does not cause any sensitization
• Nontoxic

A Mixture of a Tetracycline Isomer, an Acid, and a Detergent (MTAD):

MTAD was introduced in 2000 as a final rinse for disinfection of root canal system. Torabinejad et al. have shown that MTAD is able to safely remove the smear layer and is effctive against Enterococcus faecalis.

Composition:

• Tetracycline:
  • It is a bacteriostatic broad-spectrum antibiotic
  • It has low pH and acts as a calcium chelator
  • It removes the smear layer
  • It has the property of substantivity
  • It promotes healing
• Citric acid: It is bactericidal in nature and removes the smear layer
• Detergent (Tween 80): It decreases surface tension

Advantages of MTAD:

• It is an effctive solution for the removal of the smear layer
• It kills E. faecalis which has been shown to be resistant to many intracanal medicaments and irrigants
• It is biocompatible
• MTAD has similar solubilizing effects on pulp and dentin to those of EDTA
• The high binding affinity of doxycycline present in MTAD for dentin allows a prolonged antibacterial effect (it is the main difference between MTAD and EDTA)

Q-MIX:

Q-Mix 2 in 1 is a colorless and odorless solution which consists of 17% EDTA and 2% chlorhexidine which can kill 99.99% of the bacteria. To be used as a final rinse, continuous irrigation of root canal is done for 60–90 s.

Functions:

Kills 99.99% of planktonic bacteria

Penetrates biofilm

Advantages of Q-MIX:

• Less demineralization of dentin as compared to EDTA
• It does not cause erosion of dentin like NaOCl when NaOCl is used as a final rinse after EDTA

Herbal Irrigants

Herbal irrigants are becoming popular now due to their biocompatibility, antimicrobial activity, and antioxidative and anti-inflammatory nature. The following are commonly used herbal irrigants:

Triphala and Green Tea Polyphenols:

Triphala’s fruit is rich in citric acid. It has a chelating property which helps in removing the smear layer. Green tea polyphenols possess antioxidant, anti-cariogenic, anti-inflammatory, and antimicrobial properties. J. Prabhakar et al. showed that Triphala and Green tea polyphenols have significant antimicrobial activity against E. faecalis biofilm.

Turmeric:

It possesses anti-inflammatory, antioxidant, antimicrobial, and anticancer activity. Studies have shown its antibacterial activity against E. faecalis and thus can be used as for root canal irrigation.

German Chamomile and Tea Tree Oil:

The active component of tea tree oil is terpinene-4-ol which possesses anti-inflammatory, analgesic, and antimicrobial properties. It helps in removing the smear layer and has activity against E. faecalis.

Allium sativum (Garlic):

Its active component is allicin which destroys the bacterial cell wall and thus can be used as root canal irrigant.

Azadirachta indica (Neem):

Neem possesses antifungal, antibacterial, antioxidant, and anticarcinogenic activity. Naiyak Arathi et al. in their study showed that ethanolic extract of neem has significant activity against E. faecalis.

Propolis:

Propolis is a resinous substance which honey bees collect from poplars and conifers. It shows antioxidant, anti-inflammatory and antibacterial activities against Streptococcus sobrinus and Streptococcus mutans. Studies have shown its antimicrobial activity comparable to that of sodium hypochlorite.

Myristica fragrans (Nutmeg):

Its main constituent myristic acid has antibacterial properties.

Spilanthes Calva DC:

Moulshree Dube et al. showed that the antibacterial efficacy of the methanolic extract of Spilathes calva DC is comparable to sodium hypochlorite.

Acacia nilotica (Babool):

Acacia nilotica have antimicrobial, antioxidant, and antibiotic properties. Research have shown that a 50% concentration of acacia shows the highest activity against E. faecalis.

Aloe vera:

Aloe vera has antibacterial and antifungal activity. It has been found to be effctive against E. faecalis and resistant microorganisms of root canals.

Method Of Irrigation

• The solution should be introduced slowly and passively into the canal
• The needle should never be wedged into the canal and should allow an adequate backflow
• The blunted needles of 26 gauge or 27 gauge is preferred
• In the case of small canals, deposit the solution in a pulp chamber. The fie carries the solution into the canal. The capillary action of a narrow canal will stain the solution.
• To remove the excess fluid, either the aspirating syringe or a 2 × 2 inches folded gauze pad is placed near the chamber. To further dry the canal, remove the residual solution with paper point
• Regardless of the delivery system, irrigants must never be forcibly inserted into apical tissues
• For effctive cleaning, the needle delivering the solution should be in close proximity to the debris to be removed
• In the case of large canals, tip of the needle should be introduced until resistance is felt, then withdraw the needle 2–3 mm away from that point and irrigate the canal passively. For removal of the solution, a sterile gauge pack or paper points should be used
• In order to clean effectively in both anterior and posterior teeth canals, a blunt bend of 30° in the center of the needle can be given to reach the optimum length to the canal
• The volume of irrigant is more important than concentration or type of irrigant

Various delivery systems for irrigation:

• Stropko irrigator
• 27-gauge needle with a notched tip
• Needle with bevel
• Monojet endodontic needle
  • 23-gauge
  • 27-gauge
• ProRinse—25-, 28-, 30-gauge probes
• Ultrasonic handpiece

Ideal properties of irrigating needle:

• An irrigating needle should
• Blunt
• Allow backflow
• Flexible
• Longer in length
• Easily available
• Cost-effctive

Different Needle Designs:

• Stropko Irrigator:

In this system, a combination of delivery and recovery of irrigant is present in one probe. It is specially used when a surgical operating microscope is used for procedures.

27-Gauge Needle with Notched Tip:

This needle is preferred as its notched tip allows backflow of the solution and does not create pressure in the periapical area. So, it ensures optimum cleaning without damage to the periapical area.

Needle with Bevel:

Needle with bevel, if gets lodged into the canal, there is a risk of forcing irrigant past the apex.

Monojet Endodontic Needle:

This is an efficient irrigant long blunt needle that can be inserted to the full length of the canal to ensure optimum cleaning.

ProRinse probe:

The design of this needle produces an upward flushing motion for complete canal irrigation. Its side port dispersal pre- vents solution and debris from being expressed through the apex and closed, rounded end reduces the risk of apical damage

Micro brushes and Ultrasonic:

In this, bristles are attached to braided wires or flexible plastic cores. An optimal-sized micro brush can be attached to a rotary or ultrasonic handpiece. These micro brushes have tapers like nonstandardized gutta-percha cones. These are used in conjunction with sodium hypochlorite and EDTA to produce clean canals.

Endovac (Apical Negative Pressure Irrigation System):

The EndoVac apical negative pressure irrigation system draws fluid apically by way of evacuation. Instead of applying positive pressure, it uses suction to pull the irrigant down the canal. This system is comprised of the following parts:

1. Master delivery tip, which allows a constant flow of irrigant without overflow
2. Microcannula, which removes coarse debris left in the canal from instrumentation
3. Microcannula, which removes microscopic debris at the apical 1 mm via 28 gauze needle with 12 laser-drilled microscopic evacuation holes

Precautions:

• Confirm the integrity of the rubber dam seal
• Protect patient’s eyes and clothing from sodium hypochlorite spill
• Never place the MDTs delivery tip closer than 5 mm from the coronal opening of the canal
• For optimal use of the EndoVac system, the canal should be instrumented to a minimum of 35 No. at a 4% taper or 45 No, if 2% taper
• Make sure no air bubbles are trapped in the prefilled syringes, as this will cause uncontrolled irrigant extrusion after releasing the plunger pressure

Positive Pressure versus Apical Negative Pressure:

Irrigation involves the placement of an irrigating solution into the canal system and its evacuation from the tooth. It is done by placing an end-port or side-port needle into the canal and expressing solution out of the needle to be suc- turned coronally. This creates a positive pressure system with force created at the end of the needle, which may lead to the solution being forced into the periapical tissues.

In an apical negative pressure irrigation system, the irrigation solution is expressed coronally, and suction at the tip of the irrigation needle at the apex creates a current flow down the canal toward the apex and is drawn up the needle. But true apical negative pressure only occurs when the needle is used to aspirate irrigants from the apical termination of the root canal.

The apical suction pulls irrigating solution down the canal walls toward the apex, creating a rapid, turbulent current force toward the terminus of the needle.