Dr William Ha BDSc GCResCommPhD (Endodontic Biomaterials) FPFA

Endodontic Biomaterials

Overview

• Part 1: Irrigants • Part 2: Medicaments• Part 3: Obturation materials

and MTA

• What’s out there?• What makes it better?• What makes it worse?• What should I use?

• And what is the literature that answers these questions?

Overview

• Part 1: Irrigants • Part 2: Medicaments• Part 3: Obturation materials

and MTA

• What’s out there?• What makes it better?• What makes it worse?• What should I use?

• And what is the literature that answers these questions?

What’s out there?

Dutner 2012. Gopikrishna 2013

0.5-6% NaOCl

• NaOCl acts on organic material, degrading fatty acids, neutralises amino acids and interferes with cellular metabolism.

Del Carpio-Perochena 2015

17% EDTA

• EDTA chelates calcium and hence:• Softens dentine to make instrumentation

easier• Has less file fracture risk than NaOCl• Breaks down the smear layer (debris

from chemo-mech prep)

• EDTA brands are mixed with Cetrimide (antiseptic detergent), but is not as anti-bacterial as NaOCl

Ostby 1957, Pashley 1984, Hampson 1964, Hulsmann 2003, Frithjof 1963, Shantiaee 2014

2% Chlorhexidine

Antibacterial

But unable to dissolve pulp tissue.

Does not dissolve biofilm

Does not remove organic debris

NOT to be used as a sole irrigant

2mg/mL is actually 0.2% (bacteriostatic) not 2% (bactericidal)

Goncalves 2016, Haapasalo 2010, Haapasalo 2011, Mohammadi 2014

Saline: 0.9% NaCl

• Only useful for flushing out irrigants and other debris

• But is otherwise inferior to other irrigants

Irrigants: What makes it better?

NaOCl strength &

time

Radcliffe 2004

NaOCl strength &

time

Radcliffe 2004

International NaOCl preferences

Dunter 2012, Gopikrishna 2013

NaOCl & tissue dissolution

Room temperature 37oC 45oC

1% NaOCl -5.52% -0.29% 1.72 %

2% NaOCl 3.95% 8.25% 14.18%

4% NaOCl 18.13% 24.93% 33.61%

5.8% NaOCl 27.28% 38.31% 48.18%

Stojicic 2010

NaOCl is the key player

Dunter 2012, Gopikrishna 2013

Primary Irrigant used by US Endodontists Primary Irrigant used by Indian Endodontists

9 out of 10 endodontists

predominately use NaOCl

Surfactants (Surface active agents)

• Reduce surface tension - how detergents help water mix with oil• Hypochlorite with surfactants• Endosure Hypochlor 1%• Endosure Hypochlor 4% Forte• Hypocelle 1%• Hypocelle 4%• Chlor Xtra 6%

• Hypochlorite without surfactants• ADM Hypochlorite 1%• ADM Hypochlorite 4%• CanalPro NaOCl 3%• CanalPro NaOCl 6%• Halas Hypochlorite 1%• Halas Hypochlorite 4

Surfactants

Rossi-Fedele 2013

Surfactants

Less Stable Guastalli Journal of Endodontics 2015 41,1344-48

No difference in tissue dissolution De-deus Journal of Endodontics 2013 39, 1039-43

Rossi-Fedele 2013

Increased tissue dissolution Almedia Brazilian Dental Journal 2013 24,477-81

Increased dentine tubule penetration Palazzi Minerva Stomatol 2016 65,368-377

Increased tissue dissolution Estevez Journal of Endodontics 2017 43, 1161-65

Increased dentine tubule penetration Palazzi Brazilian Dental Journal 2016 27, 208-16

Increased antibacterial activity Giardino Iran Endodontic Journal 10, 174-8

Surfactants

• Better penetration of hypochlorite• Better antibacterial activity,

• Increased tissue dissolution

• But there are still problems with stability.

Palazzi 2016, Wang 2012, Estevez 2017, Gustalli 2015

EDTA makes NaOCl

penetrate better

• The use of EDTA before NaOCl removes the smear layer to open the dentinal tubules to facilitate deeper penetration of NaOCl. (Gulabivala 2005) The combined use of EDTA and NaOCl is more efficient than NaOCl alone. (Bystrom 1985)

• The use of additive EDTA to NaOCl has a mild positive effect. But, in re-treatment, there is significantly positive effect. (Ng 2001)

• “EDTA + NaOCl is good”

NaOCl immediately added to EDTA will exert its full antibacterial activity. But, EDTA should not be premixed with NaOCl prior to irrigation it will de-activate the ingredients. (Senna 2018)

• “EDTA + NaOCl is bad”

EDTA will cause NaOCl to lose some activity. Hence, copious amounts of NaOCl should be administered to wash out the remnants of EDTA. (Grawher 2003)

EDTA Time

• For purposes of removing the smear layer, the optimal regimen is a final rinse with • 1 mL of 17% EDTA for 1 minute • followed by a 3-mL rinse with 6% NaOCl • Using a 28-gauge or 30-gauge irrigating needle tips • Placed 1 mm short of working length

Saito 2008

Why do I need to be 1mm from the apex?

Darcey 2016

Getting 1mm from the apexPTN X2

(ISO 25 tip, ~06 taper) Nearest ISO Nearest binding irrigant tip

Distance from working length (mm)

File diameter (mm) Nearest File size

Needle outerdiameter (mm)

Birmingham gauge (G)

9 0.84 80 0.81 20

8 0.77 80 0.71 21

7 0.70 70 0.71 22

6 0.63 60 0.64 23

5 0.56 55 0.57 24

4 0.50 50 0.51 25

3 0.43 40 0.41 27

2 0.37 35 0.36 28

1 0.31 30 0.31 30

0 0.25 25 0.26 31

In anISO 25 (X2) preparation

Gauge 30 (ISO 31) vs

Gauge 27 (ISO 41)

In anISO 30 (X3) preparation

Gauge 30 (ISO 31) vs

Gauge 27 (ISO 41)

Realistically

If you want to irrigate 1mm short of the apex with a Gauge 30, you need to prep to at least ISO 30

If you want to irrigate to a prep size of ISO 25, your irrigant should be 2mm short of the apex. Otherwise your irrigant needle will bind at 1mm short of the apex and can lead to extrusion.

Getting your irrigant to length

• For irrigants to be effective, irrigants need to be close to the apical region and a 30 gauge needle is more effective than a larger gauge needle

• Closed-end side vented needles are more effective than standard or notch tip in removing dye

Abou-Rass 1982, Kahn 1995, Boutsiokis 2010

Not all LA needles are Luer lock Morita needles are Luer Lock, Septodont needles are not

If using a 27 G needle, prep to size ISO 30 (e.g. X3)

If using a 30 G needle, prep to at LEAST size ISO 25 (e.g. X2)

Khademi 2006, Boutsiokis 2010

Apical size and Irrigant Gauge

Method Size 25 file at apex , step back flaring Size 40 at apex, step back flaring

Clearance Quality Clean to apical third

Clean to mid root-only

Clean to coronal third-only

Clean to apical third

Clean to mid root-only

Clean to coronal third-only

Irrigant into chamber-only and stirred in canal with 15 file

54% 40% 6% 52% 48% 0%

23 Gauge to mid root (roughly ISO 60)

60% 33% 6% 70% 30% 0%

30 Gauge to apical third (roughly ISO 30)

90% 8% 2% 98% 2% 0%

Abou-Rass 1982

Why we activate / agitate

Gubivala 2010, de Gregorio 2009

Vapour lock

Irrigant activation: Average parameters and differences

Virdee 2017

Manual dynamic activation 90-120 sec 30/02-40/06 GP 100 strokes

Passive ultrasonic activation 60-120 sec 15/02-20/02 File setting ~5

Sonic activation 60-90 sec 25/04 2mm from WL

Apical negative pressure 90-360 sec 3 cycles 0 mm from WL

• There is no clear difference in outcomes between methods for a particular technique to be recommended. All improve intracanal smear layer and debris removal compared to conventional needle irrigation

• Gutta percha similar to the apical size is pumped up and down• Tapered (06) GP is better than a non-tapered (02) GP.• Moves irrigant laterally, but not apically

Manual dynamic activation / “GP pumping”

Jiang 2012

Clean groove < 50% debris > 50% debris 100% debrisConventional irrigation

0% 0% 0% 100%

MDA (non tapered GP)

0% 5% 45% 50%

MDA (tapered GP) 5% 50% 45% 0%

Passive ultrasonic 55% 45% 0% 0%

Negative apical pressure

0% 0% 35% 65%

• Tip resembling GP point in dimension is inserted and activated• Saves manual pumping up and down and provides greater lateral energy• Slightly better than using manual dynamic activation

• Moves irrigant laterally, but not apically

Sonic activation (Endoactivator)

de Gregorio 2010

Final irrigation PLUS:

Apical third Middle third

No activation 3.16+0.958 3.47+0.874

Master cone(Manual dynamic)

2.21+1.032 2.05+1.05

Endoactivator(Sonic activation)

1.75+0.55 1.88+0.857

1 = clean, 5 = unclean

• Also known as Passive Ultrasonic Irrigation (PUI)• Passive = should NOT be touching the walls as it may file the tooth creating debris• Difficult to remain passive at length in curved canals

• Endodontic ultrasonic file is inserted and activated• Moves irrigant laterally, but not apically

Passive Ultrasonic Activation

de Gregorio 2010

Sonic activation (EDDY, VDW)

• Connects to certain ultrasonic handpieces• Ie. 5000-6000Hz instead of 190Hz for Endoactivator (Dentsply)• Longer tips (28mm) than Endoactivator (22mm)

• Seems to clean as well as passive ultrasonic irrigation• May be better than the Endoactivator• But some studies say there’s no difference

• New so studies are few

Urban 2017, Conde 2016

• Fine suction tip is inserted into the canal and sucks down irrigant• Moves irrigant apically, but not laterally• Prevents extrusion better than normal irrigation

Negative Apical Pressure(EndoVac)

de Gregorio 2010, Mitchell 2010

Vs conventional irrigation (positive pressure)

Ultrasonic activation and Negative apical pressure

Spoorthy 2013

Conventional irrigation

Negative apical pressure

Passive ultrasonic irrigation

Combined

Activation types, another study

Passive Ultrasonic

Negative apical pressure

Combined Positive pressure (conventional irrigation)

Reached working length, n (%) 37.5% 100% 100% 25%

Lateral canals penetrated, n (%)2 mm (from WL) 25% 0% 69% 0%

4.5 mm (from WL) 69% 13% 94% 0%6 mm (from WL) 94% 25% 94% 0%

Spoorthy 2013

EndoVac is OFF the market• The suction tip is Gauge 28 (ISO 32)

• Fine tips could easily get clogged with debris

• Lots of wires

• You could use endodontic suction tips• E.g. Roeko Surgitip

• But the out diameters are too large• E.g. Gauge 23 (ISO 60)

But the problem with passive ultrasonic irrigation• Activated files cut and can cause transportation• Possible creation of debris and hence increasing smear layer

Group Dissolution distance in inner simulated accessory canals

Dissolution distance in outer simulated accessory canals

Transportation

No NaOCl activation 0.1 + 0.1 mm 0.1 + 0.2 mm 0.00 + 0.00 mm

Straight SS US file 2.0 + 0.9 mm 2.0 + 1.4 mm 0.15 + 0.05 mm

Prebent SS US file 1.5 + 1.1 mm 1.4 + 0.6 mm 0.05 + 0.05 mm

NiTi US file 1.6 + 0.9 mm 2.9 + 1.2 mm 0.00 + 0.00 mm

S plastic tips 0.2 + 0.2 mm 0.2 + 0.2 mm 0.00 + 0.00 mm

Al-Jadaa 2009

Hypochlorite penetration (µm) over time, concentration, temperature

Two minutes 5 minutes 20 minutes

Zou 2010

Temperature and time with 2% NaOCl

Nio 2017

So should I heat up my irrigant?

• Temperature rises above 10oC during endodontic treatment can cause irreversible damage to the PDL resulting in ankylosis and resorption.

• Although the use of the use of heated instrument with the pulp space typically does not reach the PDL. Prolonged use of heat can be transmitted to the PDL.

Eriksson 1983, Atrizadeh 1971, Buchanan 1994, Barnes 2017

Heating NaOCl

• But it takes 30 seconds for irrigant in the canal to reach body temperature. Irrespective if it was heated (66deg) or at room temperature (19 deg)

de Hemptinne 2015

Heat and file fracture

• Heated temperatures increases the risk of file fracture and shouldn’t be used during rotary instrumentation.• If heated irrigant is to be used, it should be used as the final rinse

before obturation.

Shen 2018, radiograph from Dentistry IQ

File fracture

• If your file fractures, you won’t be able to instrument to the apex.

(PTU in 10-20o canals)

Shanitaee 2014

LASERS – will they get to the apex?

A summary

• I can send you more information on lasers but I figured not many members use lasers.

How it works Advantages Disadvantages Cleaning ability References

Photon Induced Photoacoustic Streaming (PIPS)

Low energy LASER explodes the water, producing shockwaves,

Removes some smear layer

Can lead to greater apical extrusion of debris

Doesn’t reduce bacteria as much as the EndoActivatorbut some samples have negative cultures. I.e. it’s ’hit or miss’. Likely affected by the shape of the canal

Arslan 2018, Balic 2016

Diode Lasers Heat up irrigant Heat is known to improve irrigant reactivity

Heat can result in PDL damage

Less effective than EndoActivator

Bago 2012

Photo-Activated Disinfection

Chemical dyes are absorbed by bacteria

Low energies are safer

The use of a dye is an extra step

No more effective than using an EndoActivator

Bago 2012

If Chuck Norris was an Endodontist

Chuck is the reason MB2 is hiding

What makes irrigants worse?

Things that reduce NaOCl efficiency

• NaOCl efficacy is reduced by:• Smear layer• Biofilm• Pus• Small canal or small prep sizes• Calcific obstructions

Del Carpio-Perochena 2015

Irrigants: What makes it worse?

Rossi-Fedele 2012

Mixture Byproducts Undesirable result Author (Year)NaOCl + EDTA Cl2 gas, Glioxilic acid Loss of chlorine activity

Degradation of EDTAGrawehr 2003Zehnder 2005, 2006Baumgartner 1987Clarkson 2011

NaOCl + CHX Orange-brown precipitate Potentially toxic compound Krishnamurthy 2010Basrani 2007Vivaqua-Gomes 2002Zehnder 2006Bui 2008Marchesan 2007

CHX + EDTA Salt, white precipitate Loss of chlorine activityChemical degradation of CHX

Rasimick 2008

NaOCl + CHX = Orange brown precipitate

• Possibly para-chloroaniline, toxic and carcinogenic• Difficult to remove

Orhan 2016

Precipitates form a chemical smear layer

Silva 2017

NaOCl stability

• The stability and shelf life is adversely affected by • Heat• Sunlight (including indirect sunlight)• Unsealed lids• Dilution into multiple containers

Clarkson 2001

Preloading Hypo

• Open syringes will drop in strength

• Metal needles can rust• Rubber stoppers can

degrade

Clarkson 2001

NaOCl extrusion

• Mostly maxillary teeth, probably due to decreased bone thickness;

• Slight tendency for cases with periapical lesions. Possibly with apical resorption opening constriction and decreased surrounding bone;

• Cases sometimes have over-instrumentation or perforations;

• Slightly more with open ended needles;• Needles range from 23 to 28 G; and• High flow rate (common with larger diameter

needles)

Boutsiokis 2013, Bosch-Aranda 2012

Increased apical pressure leads to extrusion

• Increased apical size reduces apical pressure

• Increased taper reduces apical pressure

• Side venting reduces pressure more than flat

Boutsiokis 2010

NaOCl extrusion

prevention

Identify higher risk cases (maxillary teeth, PA lesions, perforations and over instrumentation)Identify

Use a closed (side venting) Luer-lok irrigation needleUse

Avoid wedging the needle into the root canalAvoid

Reduce the rate of flow by using smaller irrigation tips (towards 30 G)Reduce

Boutsiokis 2013

Chlorhexidine extrusion

• There does not appear to be any literature on chlorhexidine extrusion

• Chlorhexidine has the potential to cause anaphylaxis in the dental setting

• 26 cases in Auckland City hospital from 1998-2009

• There have been two deaths in the UK associated with irrigation of dry socket.

Pemberton 2016, Willis 2009, Daly 2012

Irrigants: What should I use?

Irrigant choicesProperty NaOCl CHX EDTA Saline Studies

Outcomes Better Worse Good with NaOCl No evidence Ng 2001

Antibacterial effect in dentine Best Better Worst Worst Morgental 2013

Ability to dissolve pulp Best Poor or Zero Some Zero Okino 2004, Beltz 2003, Arslan 2015

Risk of periapical tissue irritation Worst Mild Mild Best Increased pulp dissolution = increase tissue damage

Ability to remove smear layer Worst Worst Best Worst Poletto 2017

Risk of rotary fracture Worst Mixed reports Good Good Boessler 2007, Peters 2005, Shanitaee 2014, Abuhaimed 2018,

Popovic 2016

Removal of CaOH Worst No evidence Best No evidence Da Silva 2011

Interaction with CaOH Good Mixed reports Bad Dilution Hamed 2014, Farhad 2012, George 2008, Siqueira 2003

Effect on resin bonding agents Mixed results Good Bad No evidence Mohammadi 2017

Interaction with MTA Stains Retards setting Retards setting Good Marciano 2015, Ha 2015

Interaction with NaOCl Toxic precipitate Precipitate / deactivation Dilution Rossi-Fedele 2012

Interaction with CHX Toxic precipitate Precipitate / deactivation Dilution Rossi-Fedele 2012

Interaction with EDTA Precipitate / deactivation Precipitate / deactivation Dilution Rossi-Fedele 2012

Interaction with Saline Dilution Dilution Dilution

Aqueous 17% EDTA vs 15% EDTA-gel/paste

Property Aqueous 17% EDTA 15% EDTA-gel ReferenceDebris and smear layer removal Better Worse Akhlaghi 2009, Chen 2011, Cruz 2014

File fracture risk Better Worse Boesssler 2007, Peters 2005, Shanitaee 2014

Apex locator accuracy Better Worse Shin 2012

Aqueous 17% EDTA vs 19-25% EDTA-gel/pasteProperty Aqueous 17% EDTA 19-25% EDTA-gel ReferenceDebris and smear layer removal Equal Equal Dotto 2007, Wadhwani 2011

4 Philosophies to irrigant use

NaOCl-centric

Alternating EDTA & NaOCl

EDTA first, NaOCl after

NaOCl + EDTA + CHX

NaOCl centric:

NaOCl for preparationBefore obturation, EDTA then NaOCl

• The more time hypochlorite is in the canal, the more biofilm and pulp remnants will be removed.

• Aims to minimise apical movement of live bacteria from the coronal area to the apex

Alternating EDTA with NaOCl

EDTA & NaOCl alternation

S1: Before chemo-mechanical prepS2: Sample after chemo-mechanical prepS16: Sample collected on the 14th day after chemo-mechanical prep

Control group: Saline-onlyCI: Conventional irrigation: irrigation with 1ml 5.25% NaOCl with a final rinse of 1ml 17% EDTA followed by 1ml of NaOClAI: Alternating irrigation: irrigation with 1ml 5.25% NaOCl, instrumentation and intracanal aspiration and irrigation with 200µL of 17% EDTA, instrumentation and intracanal aspiration.Final rinse with with 1mL of 5.25% NaOCl Soares 2010

EDTA for prep, then NaOCl after prep• Prevents and removes OBSTRUCTIONS

• EDTA Removes smear layer and medicament residue better during mechanical preparation

• EDTA reduces the risk of rotary fracture, softens dentine to make preparation easier

• Until the apical preparation has reached ISO 30, NaOCl will not be able to reach the apex. You might as well use an irrigant that will make your life easier

• Until the working length is determined, irrigating with EDTA has less extrusion risk than NaOCl

Ostby 1957, Da Silva 2011, Abbott 1991, Shanitaee 2014

EDTA for prep, then NaOCl after prep

• EDTA-alone detaches more E.faecalis than NaOCl-alone (but alternating is best)

Ozdemir 2010,

NaOCl prep, EDTA after prep, CHX final rinse

NaOCl first to kill a broader range of bacteria and acts against biofilm and residual pulp tissue.

EDTA to remove the smear layer and prevent NaOCl interacting with CHX

CHX last as it a more specific activity against certain bacteria and candida. It has less activity against biofilm and residual pulp tissue.

This has lost popularity as a meta-analysis in 2011 showed there were greater failures when CHX was used.

Mohammadi 2009, Haapasalo 2011, Ng 2011

My Irrigant recommendations

NaOCl-centric - If calcific obstructions are less of an issue (e.g. wide canals) OR there is substantial organic tissue (inflamed or necrotic pulp) to remove

Alternating EDTA and NaOCl is good for routine cases

EDTA for prep and NaOCl after is good when you have calcifications, narrow canals or where perforation or extrusion is a risk.

Don’t use the NaOCl+EDTA+CHX method

My irrigation activation recommendations

Best after chemo-mechanical preparation is complete for better diffusion of energy as there is less debris encountered.

Cleaning laterally:

•Ultrasonic NiTi > Ultrasonic SS > EDDY > Endoactivator > Manual pumping

Cleaning apically:

•Negative apical pressure and/or •Prep to a size ISO 30 and/or•Use Gauge 30 needles

Cleaning in general

•Higher concentrations of NaOCl are better and use with EDTA

Combining methods leads to better cleaning.

Re treatment solvents

Disslution Chloroform Eucalyptol Orange Oil EndoSolv E

Gutta Percha Best Average Average Average Scelza 2008, Gomes 2013, Pecora 1993, Hwang 2015

AH Plus (epoxy) Best Worst Average Average Alzraikat 2016, Bayram 2015, Mushtaq 2012

AH 26 (epoxy) Better Worse Alzraikat 2016

RealSeal SE(methacrylate) Best Worst Average Average Alzraikat 2016, Bayram 2015

MTA Fillapex (salicylate) Best Worst Average Average Alzraikat 2016, Bayram 2015

Sealapex (salicylate) Better Worse Alzraikat 2016

TubliSeal (eugenol) Best Worst Average Average Alzraikat 2016, Bayram 2015

If Chuck Norris was an Endodontist

Chuck’s tears remove all biofilm and the smear layer. Unfortunately he has never cried.

Questions?

• Any further questions,please feel welcome to email me at • w.ha@uq.edu.au

• Or add me on Facebook or LinkedIn• https://www.facebook.com/liamha• https://www.linkedin.com/in/drwilliamha/