History of Endodontics aae/abe



Download 0.95 Mb.
Page22/29
Date conversion20.11.2016
Size0.95 Mb.
1   ...   18   19   20   21   22   23   24   25   ...   29

EAL





  1. Suzuki 1942 – Original study (Dogs), flow of current thru teeth, electrical resistance between PDL & oral mucous membrane (lip) = constant value 6.5K ohms, speculated could measure length of root canal using electrical resistance




  1. Sunada 19621st EAL - applied Suzuki’s findings to humans, using direct current, constant resistance between PDL & mucous membrane (lip) = 6.5 K ohms




  1. Kobayashi 1995 3rd generation EAL - developed the Ratio Method. Root ZX simultaneously measures the impedance of 2 frequencies at 8 and 0.4 kHz and calculates a quotient of the impedance values expressed as a location of file on the EAL




  1. Baumgartner – Root ZX accurately locates minor diameter ~90% of the time

EAL


  1. Ounsi/Naamanex vivo, Root ZX accurately locates (+/- 0.5 mm) the AF (“Apex” mark): 84.2%, AC (“0.5” mark): 50%. Use the AF mark only!




  1. Shabahangin vivo/ex vivo, Root ZX accurately locates (+/- 0.5 mm) the AF: ~96% (using the “0.5” mark NOT “APEX” as indicator for AF)




  1. Fouad/Krell 1990 – Eval of 5 EALs: 55-75% +/- 0.5 mm of AF;  0.5 mm is clinically appropriate based on practice of subtracting 1 mm from EAL length


How accurate is radiographic working length estimation?


  1. Weiger 2001 – Radiographic WL 0-2mm short of apex causes unintentional overinstrumentation in 51% of premolars and 22% of molars.




  1. Fouad/Krell 1990 – Radiographic WL Accuracy: 53% (eval of 5 EALs)




  1. Hembrough 1993 – Max DB/P canals, Radiographic WL Accuracy: 88.5%, EAL Accuracy (SonoMark III): 73.1%. Radiograph better than EAL.



Uses of EAL





  1. Katz – root length measurement in primary dentition




  1. Fuss - locate root perforations



Does any solution effect the Root ZX?


No

  1. Meares et al – Root ZX not adversely affected by presence of NaOCl (w/in 0.5 mm of AF 83%)

  2. Jenkins JOE 2001– No difference in length determination as a function of the seven irrigants used (w/in 0.31 mm of AF): 2% Lidocaine, 5.25% NaOCl, RC prep, EDTA, Peridex, Hydrogen Peroxide, Saline

Does apical resorption affect the Root ZX?


No

  1. Goldberg – Apical root resorption did not effect determination of FWL



Does Pre-Flaring help with the Root ZX?


Yes

  1. Ibarrola – Apical foramen could be reached more consistently by preflaring the canals before obtaining working length with EAL (13/16 vs 14/16)



Does pulp status matter with the Root ZX?


NO

  1. Dunlap 1998 – In Vivo, NO statistical difference in accuracy for AF between between vital and non-vital cases with Root ZX (Vital= 0.2 mm, Necrotic= 0.5 mm, NSD). Necrotic cases had more readings past the AF.




  1. Pommer – vital more accurate than non vital with non ratio units

Can you use an EAL with a pacemaker patient?





  1. Garofalo 2002In Vitro, 4 of 5 EALs tested did not cause inhibition or interfere with normal pacemaker function




  1. Wilson/Baumgartner 2006In Vivo, 2 EALs and 1 EPT did not interfere with cardiac pacemaker or cardioverter/defibrillator in 27 patients




  1. Baddour JADA 2011 – Review – No antibiotics needed for pacemakers/cardiodefibrillators


Irrigation


Is an Irrigant Necessary?


  1. Baker JOE 197570% more debris remaining in canals instrumented w/o irrigation; Flushing action of solvent  debris;  volume,  solvent effect




  1. VandeVisse/Brilliant JOE 1975 – Instrumentation without irrigation – Files bind/separate and block canals with debris; #50 file  debris extrusion




  1. Bystrom & Sundqvist 1981 – Mechanical instrumentation reduced the number of bacteria 100 – 1000 fold and bacteria persisted even after 4 visits




  1. Peters – While instrumentation of canals increased volume and surface area, all instrumentation techniques left 35% or more of the canals’ surface area unchanged (Paque/Peters60-80% Oval shaped canal surface undebrided)

Instrumentation w/o Irrigation: Debris, Files binding/separating, Inability to completely clean



How large should the apical preparation be for irrigation?


  1. Salzgeber/Brilliant JOE 1977 – Canal must be instrumented to size 35 hand file (.02)/Gates #2 for irrigation to penetrate the apical extent of the canal (Mand. Molars & R.O. Dye)




  1. Abou-Rass/Piccinino 1982 – A 30 gauge irrigation needle can be placed in the apical 1/3 of the canal when the apex is size #30.




  1. Boutsioukis/Van der Sluis IEJ 20103-D computational flow dynamics, canals instrumented to a 35/.06 or greater improved apical irrigation flow (side vent needle – 30 g)




  1. Chow 1983 – Size 40




  1. Ramz 1977


Discuss Irrigation Devices


  1. Kahn/Rosenberg 1995 – The Max-i-Probe syringes (side-vented 2mm from closed end) were the most effective instrument used to clear dye from the simulated canals in both the mandibular and maxillary positions. Canals were instrumented to size 30 or 35 file. Compared with end-vented Monoject syringes, Cavi-Endo (ultrasonic), and Micromega (sonic) irrigation devices.




  1. Siu/Baumgartner 2010 – In vivo, EndoVac vs. Conventional side vented needle (30 g), evaluated Tissue debris (cleanliness): 3 mm from WL: EndoVac = Conventional, 1 mm from WL: EndoVac > Conventional




  1. Desai/Himel 2009 – In vitro, EndoVac no debris extrusion, Endo Activator (sonic) insignificant debris extrusion, Max-i-Probe = Ultrasonic = Rinsendo for significantly greater debris extrusion periapically



Delivery of Irrigation
Side-Vented Needle:

  1. Boutsioukis/Van der Sluis IEJ 2010 – 3-D computational flow dynamics - side vent needle (30 g) - irrigant flow 1.5 mm beyond tip




  1. Boutsiouskis/Lambrianidis JOE 2010 – Side vent needle (30 g) achieved adequate irrigant replacement within 1.0 - 1.5 mm apical to tip


Passive Ultrasonic Irrigation (PUI):

  1. Van der Sluis IEJ 3-D computational flow dynamics - Irrigant flow 3.0 mm beyond ultrasonic tip


Irrigation and Dentinal Tubules


  1. Buck/Eleazer 1999 – In vitro infection of dentinal tubules; Irrigants can peneterate well into tubules, effectiveness dependent on type of bacteria




  1. Orstavik/Haapasalo 1990 – In vitro (dentin sections) infection of dentinal tubules. Presence of smear layer impaired ability of irrigants and medicaments from penetrating into the dentinal tubules. Resistance of E. faecalis infection to intracanal medicaments may be partly due to density of tubular infection.




  1. Pashley


Irrigation and Biofilms


  1. Clegg 2006Polymicrobial biofilm created on root dentin hemisections, SEM analysis: 6% & 3% NaOCl – Disrupt & Eliminate biofilm; 1% NaOCl & 1% NaOCl/EDTA – Disrupt but not eliminate biofilm; 2% CHX – No disruption of biofilm; 6% NaOCl only irrigant to render bacteria non-viable, disrupt and eliminate biofilm




  1. Dunavant 2006 - E. faecalis biofilm grown in flow cell system% Bacteria Kill: 6% NaOCl>1%NaOCl>>Smear Clear>2%CHX>REDTA>MTAD




  1. Wang/Shen/Haapasalo 2012E. faecalis biofilms in dentinal tubules. Utilized Confocal Laser Scanning Microscopy (CLSM) for evaluation of biofilm disinfection. Qmix = 6% NaOCl > 2% CHX or 2% NaOCl for antibacterial effects on 1-day old biofilm (“young”) but 6% NaOCl > QMix > 2% NaOCl or CHX for 3-week old biofilm (“mature”)


Mechanisms of Action
ZehnderIrrigation Review:

  1. NaOCl: Halogen releasing compound, High pH, Chlorine oxid (HOFR)

  2. CHX: Bisguanide, Strong base, no tissue disol., more effect. on Gram +

  3. EDTA: Polyprotic acid, chelating metal ions (Ca+2), mild antibact.


EstrellaNaOCl Mechanisms of Action:

  1. Tissue Solvent – Hypochlorous acid releases chlorine, formation of chloramines, and leads to amino acid degradation and hydrolysis

  2. Antibacterial effectsHOFR = Chlorine

    1. Inhibits bacterial enzymes/disrupts cellular metabolism thru Chlorine oxidation

    2. Strong Base – pH > 11 – similar mechanisms to CaOH2

      1. Interferes with cell membrane integrityphospholipid degradation

      2. Inhibits enzyme activity through protein denaturation

Discuss NaOCl. What concentration is best?


  1. Harrison/Baumgartner 1978 – 5.25% is safe for clinical use, does not increase Inter-appt pain (measure of clinical toxicity)




  1. Hand/Harrison 1978 – Dilution of 5.25% NaOCl significantly inhibits the Tissue dissolving ability of NaOCl




  1. Rosenfeld JOE 1978 – 5.25% NaOCl dissolves vital pulp tissue/predentin (non-specific), does not dissolve calcified tissues or lateral canal tissues




  1. Harrison/Hand 1981- Dilution of 5.25% NaOCl significantly inhibits the Antibacterial properties of NaOCl


Discuss NaOCl. What concentration is best? Continued


  1. Cunningham 1980 – 2.6% sodium hypochlorite solution at room temp was found to be equally effective as a collagen-dissolving agent when compared to 5.25% at body or room temp. Inc. temp, inc. efficiency.




  1. Stojicic/Haapasalo 2010 – NaOCl & Bovine muscle tissue dissolution:  dissolution =  Conc. NaOCl (5.8%, 4%, 2%, 1%),  Temperature (45 vs. 37 C),  Agitation (UltraSonic, Sonic, Pipetting),  Surface active agent




  1. Clegg 2006Polymicrobial biofilm created on root dentin hemisections, SEM analysis: 6% & 3% NaOCl – Disrupt & Eliminate biofilm; 1% NaOCl & 1% NaOCl/EDTA – Disrupt but not eliminate biofilm; 2% CHX – No disruption of biofilm; 6% NaOCl only irrigant to render bacteria non-viable and eliminate biofilm from hemisections



Discuss NaOCl. What concentration is best? Continued


  1. Dunavant 2006 - E. faecalis biofilm grown in flow cell system% Bacteria Kill: 6% NaOCl>1%NaOCl>>Smear Clear>2%CHX>REDTA>MTAD




  1. Wang/Shen/Haapasalo 2012E. faecalis biofilms in dentinal tubules. Utilized Confocal Laser Scanning Microscopy (CLSM) for evaluation of biofilm disinfection. Qmix = 6% NaOCl > 2% CHX or 2% NaOCl for antibacterial effects on 1-day old biofilm (“young”) but 6% NaOCl > QMix > 2% NaOCl/CHX for 3-week old biofilm (“mature”)




  1. Bystrom & Sundqvist 1985 – No difference was noted between the antibacterial effect of 0.5% and 5% NaOCl. The combined use of EDTA/NaOCl was more efficient, but did not eliminate all the bacteria. Bacteria that survive the instrumentation and irrigation rapidly increase in numbers between appointments.


Heating the NaOCl & Tissue dissolution


  1. Cunningham 1980 -  Heat (37 vs 22),  Tissue disolution effect of NaOCl




  1. Stojicic/Haapasalo 2010 – NaOCl & Bovine muscle tissue dissolution:  dissolution =  Conc. NaOCl (5.8%, 4%, 2%, 1%),  Temperature (45 vs. 37 C),  Agitation (UltraSonic, Sonic, Pipetting),  Surfactant


Discuss Sodium Hypochlorite accident


  1. Becker 1974 – Case report – swelling, ecchymosis, severe pain, hemorrhage w/in canal – Tx: Antibiotics, Corticosteroids, Anaglesics




  1. Gluskin – Tx: long acting anesthetic (marcaine), irrigation with saline to dilute, antibiotics (Amoxicillin), analgesics, steroids, cold compress

Discuss EDTA as an irrigant
EDTA = Ethylene Diamine Tetraacetic Acid

  • Act as metal ion chelator, strips Ca+2 ions from mineralized dentin (softens dentin)

  • Polyprotic acid

  1. Nygaard-Otsby 1957 – 1st to discuss EDTA as root canal irrigant, softening dentin allows instrumentation of curved canals




  1. Zehnder 2006 – EDTA is effective demineralizing agent, highly biocompatible, removes inorganic smear layer, limited antiseptic capacity




  1. Haapasalo 2010 – Review – EDTA dissolves inorganic material, including hydroxyapatite. No effect on organic tissue. No antibacterial effect.

EDTA – a disodium salt solution that collects Ca ions and replaces with Na, making dentin softer – Chelates Ca+2 ions (binds/strips from dentin)



RC Prep – introduced by Stewart

Old formulation – 3.8% EDTA, Urea peroxide, propylene glycol, carbowax



New formulation – 3.8% EDTA, Urea peroxide, propylene glycol


  1. del Rio 1975 - Old formulation remained after instrumentation




  1. del Rio 1976 – RC Prep caused increased apical leakage of radioactive iodine, less was noted in cases sealed with gutta-percha than with silver wires.




  1. Schafers 2002 - New formulation improved cleanliness of the root canal walls in the coronal and middle parts of the root canal




  1. Peters IEJ 2005EDTA liquid > Glyde (EDTA) Paste -  Max. Torque values (ProFile),  Full Torsional load over time (ProFile/ProTaper); Glyde  Apical directed force (ProFile)

What is the smear layer?


  1. McComb & Smith JOE 19751st to describe the smear layer: Smear Layer = surface layer completely obscuring the dentinal tubules composed of superficial debris and embedded erythrocytes scattered over the surface




  1. Mader/Baumgartner 1984SEM analysis of smear layer - found 2 components:

    1. Surface Layerthin layer, amorphous/irregular - 1-2 microns thick

    2. Dentinal Tubule Layer – irregular finger projections into dental tubules, variable distances up to 40 microns




  1. Sen 1995 – The smear layer is made up of inorganic and organic debris. (Pulpal tissues, Dentin debris, bacteria, bacterial TEBs: Toxins/Enzymes/Byproducts)

Does the smear layer effect the apical or coronal seal?

YES


  1. Cergneux/Holz 1987 – Better apical seal occurred when the smear layer was removed with EDTA




  1. Jeansonne 1997 – Less coronal leakage was seen when the smear layer was removed. AH-26 displayed less leakage than Roth’s 811sealer


NO


  1. Madison/Krell 1984– Apical seal (dye leakage) for obturation is not improved by irrigation w/EDTA. Compared NaOCl vs NaOCl+EDTA. No difference in apical seal integrity with or without smear layer removal.


Should the smear layer be removed?

YES

  1. Torabinejad 2002 – Infected cases - removal of smear layer to decrease bacterial infection and improve adaptation of obturation materials




  1. White/Goldman 1984 Penetration into dentinal tubules by filling materials is possible after the smear layer removal




  1. Wang/Shen/Haapasalo 2013 – Smear layer reduces the effectiveness of irrigants (6% NaOCl, 2% CHX, QMix) – E faecalis biofilm/dent. tubules




  1. Cergneux/Holz 1987 – Better apical seal when smear layer removed




  1. Jeansonne 1997 – Better coronal seal when smear layer removed

NO

  1. Drake 1994 – do NOT remove smear layer, smear layer inhibits bacterial penetration of dentinal tubules

How much/long should EDTA be used?


  1. Crumpton – In vitro, 1 mL/1 min of 17% EDTA = 10 mL/1 min of 17% EDTA for smear layer removal; Use 1 mL for 1 min to remove smear layer




  1. Saito/Webb – In vitro, 1 min EDTA rinse




  1. Calt/Serper 20021 minute irrigation of EDTA is effective in removing the smear layer. A 10 min application of EDTA causes excessive peritubular (intertubular) dentinal erosion




  1. Schilder EDTA self-limiting at 7 hours

Discuss EDTA/NaOCl combination for irrigation:


  1. Yamada/Goldman 19831st to evaluate EDTA/NaOCl combination as a final flush to remove both inorganic and organic components; For overall canal cleanliness (SEM), use final flush w/ 10ml of 17% EDTA (inorganic-smear layer) followed by 10 ml of 5.25% NaOCl (organic-debris)




  1. Baumgartner/Mader 1987 – 5.25% NaOCl and 17% EDTA more effective than NaOCl and saline for smear layer removal. NaOCl/EDTA combination removed all smear layer as well as pulpal remnants/predentin on uninstrumented side

Discuss MTAD

Mix + Tetracycline + Acid + Detergent

  1. Torabinejad 2003 – MTAD appeared similar to EDTA in solubizing effect on pulp and dentin. It had a high binding affinity of doxycycline for dentin.




  1. Torabinejad 2003 – MTAD killed E. Faecalis in human dentinal tubules in 5 minutes and was more effective than 5.25% NaOCl.




  1. Torabinejad 2003 – 1.3% NaOCl is recommended for irrigation to compliment MTAD (reduced antibacterial properties)




  1. Torabinejad 2003 – Components:

    1. Doxycycline – Prevents E. Faecalis in 100% of samples

    2. Acid – Removes smear layer w/out erosion of dentin

    3. Tween-80 (Detergent) – Reduces surface tension, increases dentin penetration

Is Chlorhexidine an effective irrigant?


  1. Jeansonne 1994 – Ex Vivo, No difference in antimicrobial activity (ex vivo, pulpal pathosis) between 2% CHX and 5.25% NaOCl, but NaOCl had added advantages of tissue dissolution. CHX is an excellent irrigating alternative for NaOCl allergic patients, perforations and teeth with open apices.




  1. White 1997 – Antimicrobial activity lasted 72 hours after use with 2% CHX, 0.12% produced 6 –24 hrs. CHX binds to dentin and is released over time = substantivity




  1. Haapasalo – CHX antibacterial effects: Permeates cell wall/membrane, attacks cytoplasmic membrane, allowing leakage of cellular contents




  1. Siqueira 2001 – Only 2% CHX was able to eliminate most of both 1 & 3 day E. Faecalis biofilms (opposes Dunavant and Wang/Shen/Haapasalo).

Is Chlorhexidine an effective irrigant? Continued



  1. Hartwell 2003 – CHX 0.12% did not adversely affect the apical seal of Roths cement at 270 and 360 days when used as an endo irrigant.




  1. Gomes 20032% CHX was more effective against E. faecalis than CaOH2 (disturbs bacterial cell wall osmotic equilibrium) see also Orstavik/Haapasalo




  1. Baumgartner 2003CaOH2 + 2%CHX was more effective killing E. faecalis in the dentinal tubules than CaOH2 + H2O.




  1. Basrani – 2% CHX better than 0.12% for Antibacterial effects




  1. YuShen/Haapasalo – CHX + US = Better antibacterial action



QMiX

QMiX = EDTA + CHX + Detergent (Smear layer removal + Antibacterial)
1   ...   18   19   20   21   22   23   24   25   ...   29


The database is protected by copyright ©dentisty.org 2016
send message

    Main page