History of Endodontics aae/abe



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Does not interact with NaOCl, Recommended as Final rinse following NaOCl


  1. Stoijicic/Haapasalo 2012QMiX and 2% NaOCl were equally effective and superior to 1% NaOCl, 2% CHX, and MTAD at killing E. faecalis and plaque bacteria in planktonic and biofilm (3 wk old) conditions




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


Irrigant Interactions

NaOCl & CHX:

Basrani – Parachloroanaline (PCA) brown ppt, mutagenic/carcinogenic

Nowicki – No parachloroanaline (PCA) in brown ppt
NaOCl & EDTA:

Zehnder – EDTA reduces free Cl-, NaOCl ineffective as antibacterial/tissue solvent

Grawehr – same as Zehnder, EDTA inhibits NaOCl’s antibacterial and tissue disolution properties through reduction of free Chlorine ions in solution
EDTA & CHX:

Racemic – white salt ppt
Long Term EDTA:

Calt/Serper10 min rinse of dentin bars resulted in excessive intertubular dentin erosion
Final Rinse – EDTA  NaOCl (See Yamada/Goldman):

Qian/Haapasalo 2011 – Intertubular dentinal erosion due to NaOCl after EDTA

Niu – Same findings as Qian/Haapasalo

Ultrasonics

What about ultrasonics? How do they work?
Cunningham 1982 Ultrasonic preps (endosonic file/irrigation) produced significantly cleaner canals and reduced smear layer better than hand instruments. Ultrasonic energizes/activates/warms irrigating solution =  solvent action
Goodman/Reader 19851st to discuss PUI – step-back vs. step-back + PUI: Step-back+PUI greater cleaning ability (isthmus 1, 3 mm/main canal 1 mm)
Ahmad/Pitt Ford 1987Acoustic streaming, not cavitation, exists with the Cavi-Endo and aids in debridement of large straight canals.
Walmsley 1989 – If endosonic files are constrained (bind) near the tip, their motion and effectiveness is decreased. Use sonic files loose in the canals.
Zeltner – Temperature increase during use of ultrasonic instrumentation improves antibacterial effect

Do ultrasonics remove bacteria?
Yes

  1. Hoshino 1998 – Ultrasonic irrigation with 5.5% NaOCl eradicated bacteria from infected dentin.




  1. Carver 2007 – Hand/Rotary/PUI Necrotic Mandibular Molars (Mesial roots) – 1 min7x more likely to have negative culture – than Hand/Rotary only. Antibacterial effect


No


  1. Hicks 1989 – Cavi-endo and hand instrumentation were equally effective in removing bacteria form the root canal.



Are Ultrasonics effective in canal cleaning?

Yes


  1. Archer/Reader 1992 – Combination step-back with ultrasonic instrumentation (3 min) resulted in a cleaner preparation than step-back technique alone in both the canals and isthmus.




  1. Hutter 1999 – 3 min passive activation of either sonic or ultrasonic produced significantly cleaner canals than hand instrumentation alone. Also, there was NSD in cleaning efficacy between sonic and ultrasonic activation.




  1. Gutarts 2005 – In Vivo, Hand/Rotary/PUI vs. Hand/Rotary only. 1 min PUI Vital Mand Molars (Mesial roots) – Sig. Cleaner Main canal/isthmuses




  1. Burleson 2007 – In Vivo, Hand/Rotary/PUI vs. Hand/Rotary only. 1 min PUI Necrotic Mand Molars (Mesial roots) – Significantly Cleaner Canal/Isthmuses (1, 2, 3 mm levels)

Are Ultrasonics effective in canal cleaning?
No


  1. Walker – NSD between sonic, ultrasonic and hand instrumentation regarding debris removal and canal wall planing in curved canals.




  1. Holz 1989 – Ultrasound in association with EDTA did not enhance the dissolving capability of this chelating agent. Neither NaOCl nor EDTA successfully removed the smear layer in the apical portion of the canal.



Ultrasonics & CaOH2


  1. Metzler/Montgomery In vitro, extracted teeth, PUI (CaviEndo, 2 min) and CaOH2 (7 days) are equal at cleaning main canals and isthmuses and are more effective than hand instrumentation + irrigation (2.6% NaOCl) alone at debriding the apical isthmuses (1 mm). Recommends 1 visit treatment – PUI irrigation (2 min), 2 visit treatment – CaOH2 (7 days).


Ultrasonics & Cardiac pacemakers/Implanted defibrillators


  1. Roedig 2010 - Ultrasonic scalers (magnetostrictive) and battery operated curing light DO interfere with pacemakers/defibrillators; EPTs, Electrosurge do not. See also: Garofalo (5 EALs), Wilson/Baumgartner (2 EALs, 1 EPT)




  1. Gomez 2013 – In vitro, Piezoelectric ultrasonics do NOT interfere with pacemakers/cardiodefibrillators

Obturation
Rational for filling 0.5 mm – 1.0 mm short of the radiographic apex
Kuttler – distance from the major (AF) to the minor diameters (AC)

0.525 mm (18-25y/o)

0.659 mm (>55 y/o)

Burch – measured from the occlusal aspect of the major diameter (AF) to the apex

Average distance for all roots = 0.59 mm




  1. SchaefferMeta Analysis of Termination of Obturation: Healed %: Group A (0-1 mm short of RA) > Group B (1-3 mm short) >> Group C (overextended past apex); Overall success: Group A 2.7% better than B and 26.2% better than C




  1. Ricucci/Langeland – I/O to the AC to prevent injury to the periapical tissues and foreign body rxn/tissue necrosis due to extrusion of sealer/gp; I/O to 1 mm short of RA should NOT be used as this may end up overinstrumenting

Discuss the Hollow Tube Theory
Richert & Dixon 1931 – Hollow tube theory: the root canal must be filled to the end of the tooth to prevent outward diffusion of circulatory elements which cause inflammation.
Disproved by: (TGW)

Torneck 1967 – This study tested the reaction of rat connective tissue to polyethylene tube implants. Best prognosis for repair was a sterile empty tube; followed by a sterile

tube with sterile tissue. Worst prognosis was with sterile tube and infected tissue.


Goldman 1965 – Teflon rods were implanted in guinea pigs. An interchange of tissue fluids into and out of the tube occurred. There was no evidence of inflammation at the open end of the rods. Disputes the “Hollow Tube” theory
Wenger 1978 – Polyethylene tubes obturated flush at one end and 1mm short at the opposite end with gutta percha and Grossman’s cement were implanted in rat tibias. The Gutta-Percha, the set Grossman’s cement and the polyethylene implant were well tolerated by the rat intraosseous tissue. There was no inflammatory response at either end of the polyethylene tubes.

Gutta-Percha
What is in gutta-percha?

Friedman 197520% gutta-percha, 66% zinc oxide, 11% heavy metal sulfates (i.e.: Barium sulfate- radiopacifier), and 3% waxes and/or resins (plasticizer).
Does age affect gutta-percha?

Kolokuris 1992 – Moisture makes gutta-percha more plastic and workable. Store in the fridge and at high humidity.
Sorin 1979Rejuvenate by alternating heating and quenching. Immersion in hot tap water (above 55 degrees C) then remove and immerse in cold tap water or alcohol for several seconds and ready for use. Cones treated as such remain stable for months.


Is Gutta-Percha biocompatible?


  1. Pascon/Spangberg 1990 – In vitro, warmed/dissolved gp - toxicity of gp is attributable to leakage of Zinc ions into the fluids




  1. Sjogren & Sundqvist 1998 – Mouse peritoneal macrophages, when exposed to gutta-percha particles, release factors which have a bone resorbing activity that is primarily due to enhanced production of IL-1.




  1. Nair 1995Large pieces of GP were well encapsulated by a collagenous capsule and the surrounding tissue was free of inflammation. Fine particles evoked an intense, localized inflammatory response, characterized by the presence of macrophages and multinucleated giant cells.


Properties of Gutta-Percha:



  1. Marciano 1993 – Both natural and commercial GP mainly have a 1-4 trans stereochemical structure (not altered by heating during GP fabrication process) and that the coloring agent is erythrosin




  1. Schilder 1974 – Thermomechanical Properties of Gutta Percha: Gutta percha exists in a beta semicrystalline state. It undergoes 2 phase transformations upon heating from 0-100C. The Beta to Alpha transition occurs at 42-49C; the Alpha to Amorphous at 53-59C. GP is Compactable, NOT compressible.

  46   56  Amorphous  slowly cooled  


  46   56  Amorphous  normal cooling  

Is latex allergy a concern with Gutta Percha?


  1. Johnson JOE 2001No cross-reactivity to latex was observed with any of the raw or clinically used gutta-percha products. The absence of gutta-percha proteins that can react with Hevea latex-specific IgE antibody supports the minimal potential for commercially available gutta-percha to induce allergic symptoms in individuals sensitive to latex.




  1. Hamann JADA 2002 – No detectable cross-reactivity between latex and commercial gutta-percha points. Gutta-percha alone is not likely to induce symptoms in patients with type I NRL allergy.




  1. Kleier JOE 1999 – Although no cross-reactivity w/GP DDS may take the following precautions

    1. Pre-test GP w/ latex sensitive pt by allergist

    2. consider premed w/ prednisone and diphenylhydramine

    3. prepare for the management of allergic rx w/ EpiPen

Latex allergy vs Gutta Percha


  1. Costa/Johnson JOE 2001 – Gutta-percha does not have the same allergenicity as latex

Gutta-percha and gutta-balata are derived from the Paliquium gutta and Mimusops globsa trees, respectively, that are in the same botanical family as the rubber tree Hevea brasiliensis. For this reason the potential for immunological cross-reactivity between the gutta-percha and gutta-balata used in endodontics and natural rubber latex (NRL) has been the subject of some controversy, because these products may be used in latex-allergic individuals. The objective of this study was to investigate the potential cross-reactivity between gutta-percha, gutta-balata, and NRL. Physiological extracts of seven commercially available gutta-percha products, raw gutta-percha, raw gutta-balata, and synthetic transpolyisoprene were each analyzed for cross-reactivity with NRL in a competitive radioallergosorbent test inhibition assay. No detectable cross-reactivity was observed with any of the raw or clinically used gutta-percha products. In contrast the raw gutta-balata released proteins that were cross-reactive with Hevea latex. We conclude that the absence of gutta-percha proteins that can react with Hevea latex-specific IgE antibody supports the minimal potential for commercially available gutta-percha to induce allergic symptoms in individuals sensitized to NRL. Because gutta-balata is sometimes added to commercial gutta-percha products caution should be exercised if products containing gutta-balata are used in endodontic care of latex-allergic individuals.



History of Obturation Techniques


  1. Schilder – Warm vertical compaction




  1. Yee – Injection thermoplasticized (warm) gutta percha




  1. Wm. Ben Johnson – 1st Carrier based obturation (ss file + warm gp)




  1. Buchanan – Continuous Wave Warm Vertical technique



Is Obturation more important than Instrumentation/Irrigation?

NO

Sabeti 2006 – Mixed German shepards, PN/AP, Instrumentation/Irrigation  Obturtion. Equal healing w/ and w/o obturation + coronal seal (@190 days). Healing depends on microbial elimination, host response, and bacteria tight seal coronally. Not Obturation.
Nair 2006 – Microbial status of apical root canal system of Mandibular Molars with AP after ONE visit NSRCT. Histo sectioning/SEM analysis: 88% canals harbored intraradicular bacteria BIOFILMS within DIALs: Dentinal Tubules (DTs), Isthmuses (I), Apical Ramifications (ARs), and Lateral Canals (LCs). Residual infection may communicate with the PDL/AP and elicit host response/derive nutrient source, promoting post-tx AP. (Vera/Siqueira)
**Entombing bacteria in GP and nutritional starvation (Peters/Wesselink) may NOT be effective, may need maximal microbial killing through CaOH2 (negative culture studies: Bystrom/Sundqvist, Sjogren, Shuping/Trope)

What spreader is best for lateral compaction? How far should it be placed?


  1. Schmidt JOE 2000 - Niti spreaders penetrate farther w/ less force than stainless, minimizing risk of vertical root fractures




  1. Joyce JOE 1998 – Niti spreaders induce stress patterns that spread out along the surface of the canals reducing the risk of vertical root fx.




  1. Walton JOE 1981 – Less leakage occurs with deeper spreader penetration (w/in 1mm or 2mm of FWL)




  1. Trope JOE 1991 – Dye study, less leakage with finger spreaders than D11T




  1. Messer JOE 1999 – Max loads and strain generated with finger plugger were lower than those generated with a hand spreader D11T. (even lower than the values at fracture). Therefore lateral compaction should not be a factor causing vertical root fracture.

Compare lateral compaction and warm vertical compaction


  1. Brothman JOE 1980 – Vertical vs Lateral – Veritcal filled more lat canals, was denser on radiograph but no difference was seen histologically, apical 1/3rd was filled equally well with both techniques.




  1. Hoskinson OOOO 2002 – Vertical vs Lateral – no difference in success, presence of AP was biggest factor, success decreased 18% for every 1mm in size of pre-operative periapical lesion.




  1. Jacobson/Baumgartner JOE 2002 – Compared post-obturation leakage in Lateral vs Continuous Wave Warm Vertical obturated canals - Lateral condensation resulted in significantly faster coronal leakage; NSD in overall leakage between the two techniques at the end of the test period.



Compare lateral compaction and warm vertical compaction


  1. C. Reader JOE 1993 – Lateral vs Warm Lateral vs Warm Vertical to fill simulated lateral canals – NSD in quality of fill between techniques but more GP was found in lateral canals with warm techniques (See Riccuci/Siqueira)




  1. Peng JOE 2007Meta-Analysis Cold Lateral vs. WVNo difference: Post op pain, Long term outcomes, Obturation quality; WV more overextensions




  1. Dulac JOE 1999 – In vitro, resin blocks w/ simulated lateral canals, Evaluated ability to obturate lateral canals: CWWV and Carrier Based (CB) better than Cold Lateral for obturating lateral canals in all 3 thirds of canal




  1. De Chevigny (Toronto study) – NSRCT - WV vs. Cold Lateral – Healed rate 10% higher w/ WV


Does obturation cause vertical root fractures?


  1. Holcomb/Pitts JOE 1987Excessive lateral force can cause VRF. Suggested condensation forces <2.5lb as “safe limited load”. This corresponds with 70% of the minimum load resulting in fractures. Fractures usually occur facio-lingually.




  1. Lindauer/Hicks JOE 1989 – Described lateral forces acceptable for treatment of mesial roots of mandibular molars without causing vertical root fractures (2.2 lbs to 10.8 lbs)

NOTE: THIS DATA CONFLICTS WITH HOLCOMB’S FINDINGS


  1. Meister 1980 – Retrospective Chart review (32 cases): Excessive lateral condensation forces caused VRFs: 84.38%



Do warm Gutta Percha techniques damage the PDL?


  1. Sweatman/Baumgartner JOE 2001 – Ex vivo (max centrals), thermocouples @ levels 0, 2, 4, 6 mm from apex. Evaluated change in radicular temp. (internal, external) using System B (200, 250, 300 C) and Obtura II (185 C) to 4-5 mm from apex. At no level did external root temperature increase more than 10 C.




  1. Gutmann JOE 1987 – In vitro/in vivo (dogs). Max temp change with Obtura thermoplast GP was 1.1 C. No inflamm/necrosis in PDL. In Vivo, PDL microcirculation  rise in external root surface




  1. Lipski JOE 2006 – In vitro, Mand/Max Incisors, Obtura II (160), Thermocamera; Outer root surface: Max: 8.5 C, Mand: 22.1 C (Caution in thin roots!)




  1. Erikkson/Albrektson - >10 C is threshold for bony necrosis

What do you know about Thermafil?


  1. Juhlin/Walton JOE 1993 – In vitro (plastic blocks), curved canal preparations, SEM/stereomicroscopic evaluation of fillMost variations in apical 1/3rd – Stripping of gutta percha from carrier, lack of sealer, Length control problems




  1. Baumgartner JADA 1995 – Lateral vs Thermafil – Thermafil leaked more, maybe due to stripping of carrier upon insertion.




  1. Gutmann IEJ 1993 – Thermafil looked better on radiograph than lateral condensation but caused more overextensions.

    1. Overfilling was common problem with Thermafil

    2. Lat condensation had more leakage at 7 days, but no difference at 24 hrs and 5 months.




  1. Wilcox – Retreatment of Thermafil

How do you sterilize Gutta Percha points?


  1. Senia JOE 1975 – Gutta percha points may be sterilized by a one minute immersion in 5.25% NaOCl.




  1. Frank JOE 1983 – NaOCl 5.25% killed spores in 1 minute




  1. Subha JOE 2013 – CHX for 1 minute rapid sterilization of GP cone


How long for sealer to set?

ZOE:

  1. Allan/WaltonRoth’s not completely set at 8 weeks; 4 weeks (Tubliseal)

Resin epoxy (hydrophobic):

  1. Allan/Walton - 4 weeks (AH26)

CaOH2:

  1. Allan/Walton – 4 weeks (SealApex)

Compare Resilon vs. Gutta Percha

Resilon = Polyester based root canal filing material (dimethacrylate polymer + Bioactive glass + CaOH2)



Tay/Pashley 2007 – Review of Monoblock theory

Monoblock:

Yes

  1. Shipper/Trope 2004 – Bacterial leakage model, Resilon/Epiphany superior to Gutta Percha/AH26 or GP/Epiphany

No

  1. Gesi/Pashley 2005compared interfacial strengths of Resilon/Epiphany and Gutta Percha/AH Plus using push out test. GP/AH Plus group exhibited significantly higher interfacial strength than the Resilon group. GP/AH Plus failed at the GP/sealer interface, Resilon failed at sealer/dentin interface. Low interfacial strengths in both groups challenges the concept of strengthening root filled teeth with resin materials.

  2. Raina/Tay/Pashley 2007 – Resilon/Epiphany sealed 17 mm root canals as well as GP/AH plus and does not create a monoblock root filling

  3. Kim/Tay 2010 – Review of methacrylate resin sealers. No benefit of methacrylate based sealers in conjunction with adhesive root filling materials

Obturation materials


  1. Gutta Percha




  1. Resilon/Real Seal – Polyester polymer (resin methacrylate, bioactive glass, CaOH2)




  1. Carrier based




  1. C-Point – Polyamide polymer w/nylon core – “self sealing”




  1. Bioceramic – Calcium silicate/Calcium phosphate


Sealers

  1. Calcium Hydroxide:

    1. Sealapex

    2. Apexit; Apexit-Plus

    3. Vitapex (CaOH2 + iodoform)

  2. Resin epoxy (hydrophobic):

    1. AH-26; AH-Plus

  3. Resin methacrylate (hydrophilic): Self-adhesive systems (no etching primer needed)

    1. Real Seal

    2. EndoREZ

    3. Epiphany

  4. Zinc Oxide Eugenol:

    1. Roth’s (511/515- slow/med set silver, 801/811- slow/med set stainless)

    2. Tubliseal/Tubliseal EWT

    3. Kerr/Kerr EWT

  5. Bioceramics (Calcium silicate/Calcium phosphate):

    1. BC Sealer

  6. MTA Silicate Resin (Dicalcium silicate, Tricalcium silicate, Tricalcium aluminate):

    1. MTA Fillapex

  7. Glass Ionomer:

    1. Ketac Endo

Sealers

  1. Brown JOE 1994 – Roth’s (ZOE) displayed less apical leakage than Ketac endo (glass ionomer) in a vacuum dye test.




  1. Weiss JOE 1997 – Ketac Endo possesses a short-acting very potent and diffusable antibacterial activity, whereas Roth’s extends its effect over 7 days after setting.




  1. Mickel JOE 1999 – Roth’s sealer had better antimicrobial activity than 3 CaOH2 sealers.




  1. Kontakiotis/Wu/Wesselink IEJ 1997 – Evaluated Sealer thickness. Compared 0.05 mm (thin) vs 0.3 mm (thick) before and after 2 yr water storage in root specimens. Thick layers of ROTH and Pulp Canal Sealer EWT leaked more than thin layers. No difference for AH-26, SealApex, Ketac-Endo. After 2 yrs, all sealers leaked more than before storage in water, with Pulp Canal Sealer EWT leaking more than others.

Sealers


  1. Allan/Walton JOE 2001AH26, Sealapex, and Tubliseal were partially set after 1 wk and set was complete after 4 wks. Roth’s was very slow, as none were completely set at 8 wks. Sealers on the glass slap set much more rapidly. In conclusison, under simulated clinical conditions, sealers set slowly (particularly Roth’s) and were more delayed than when tested in vitro.




  1. Hume 1984 – Cytoxic effects of ZOE as pulp capping agent: Eugenol is cytotoxic, neurotoxic. Diffuses through dentin. Fresh not set form.




  1. Leyhausen JOE 1999 – Genotoxicity and Cytotoxicity of resin-based sealers (AH-Plus, AH-26)

    1. AH-Plus: Slight to no cellular injuries, No mutagenicity

    2. AH-26: Cytotoxic due to formaldehyde release, not in AH Plus




  1. Langeland – All sealers toxic when mixed – reduced on setting

Is sealer extrusion a concern?


  1. Bernath IEJ 2003

    1. Apex & Grossman’s (ZOE) = no periapical inflammation if confined to canal

    2. AH-26 & Endomethasone = + periapical inflam even if confined to canal

    3. All 4 initiated periapical inflammation if overfilled




  1. Baumgartner/Svec JOE 1983 - Extrusion of sealer or gutta-percha was associated with increased pain in vital cases w/o AP. Overall incidence of post-obturation pain was 47.6% (14% Severe)




  1. Augsburger/Peters JOE 1990Extruded sealer did NOT prevent healing, was removed from apical tissues over the 6 year follow-up period.

Is sealer extrusion a concern? continued


  1. Loushine 2011 – All sealers tested (AH Plus, Endo Rez, BC Sealer) were initially cytotoxic. AH Plus became non-cytotoxic over 6 week period while BC Sealer remained moderately cytotoxic.




  1. Ruparel/Diogenes 2014 – Effect of Endo sealers on Trigeminal neuronal activity. ZOE (fresh/set forms) and AH-Plus (fresh form) evoked significant CGRP release while EndoSequence BC and RealSeal Sealer reduced CGRP release. Eugenol alone evoked 7.5x inc in CGRP release. **Periapical extrusion of sealer (esp ZOE) may lead to direct activation of nociceptors/neurogenic inflammation/central sensitization/chronic pain




  1. Huang 2002Calcium hydroxide sealers (SealApex) were less cytotoxic than ZOE sealers and Resin epoxy sealers (AH-Plus, AH-26) for Human PDL cells

Discuss Sargenti paste

AAE Position Paper (Sargenti paste, N2, RC2B)

  1. Sargenti technique – No rubber dam needed, Length – somewhere near apex, objective is chemical fixation (not clean and shape), opposes irrigation, suggests trying to keep N2 paste in canals but it is “well tolerated” in PA tissues. 4-7% paraformaldehyde, contains lead tetroxide.




  1. Newton 1980 – Monkey study, demonstrated at 6 mo and 1 yr that teeth obturated with N2 technique and RC2B paste developed severe apical pathosis Granuloma, Abscess, or Osteomyelitis




  1. Spangberg 1974Formaldehyde is responsible for extensive tissue necrosis. Not resorbable therefore must be surgically removed if expressed beyond apex




  1. Hata/Toda 1989Systemic distribution of 14C labeled formaldehyde: blood, lymph nodes, liver, kidneys, spleen




  1. AAE Paper – Destruction of periapical tissues, paresthesia, dysathesia, pain

What internal matrix material can be used when repairing a perforation?

  1. Hydroxyapetite - Lemon

  2. DFDBA - Hartwell

  3. Gelfoam – Walia, Hartwell

  4. CaOH2 – Peterson, Frank & Weine

  5. Collacote – Rosenberg

  6. Calcium phosphate – Chau

  7. Calcium sulfate – Alhadainey


Torabinejad OOO 1996 – Case report: MTA used in furcation perforation, no internal matrix is recommended.
Baumgartner JOE 1998 – Perforations repaired with MTA leaked less than amalgam
Saunders JOE 2002 – MTA leaked less than those repaired with Vitrebond

Discuss lateral root perforations


  1. Fuss/Trope 1996 – REVIEW article on Root Perforations:

Prognostic Factors:

    1. Time – Immediate repair  success (Seltzer 1970)

    2. Size – Smaller the perf,  success – ability to seal

    3. Location - #1 factorCritical zone = Level of crestal bone/connective tissue/epithelial attachment – Lowest success due to bacterial infection/epithelial downgrowth/sulcular communciation  bone loss (perforation above or below this level is better!)

See also Jew; Mente (86%), Krupp/Hulsmann (73%, 2 prognostic factors – Pre-op RL associated with perforation and Sulcular communication)


Goals: Arrest inflammatory rxns, Preserve or promote regrowth of tissue attachment adjacent to perforation, Prevent bacterial infection (and subsequent downgrowth of epithelium)

MTA & Perforation Repair


  1. Holland JOE 2001No inflammation was seen and cementum was deposited over MTA in this dog study of lateral root perforations




  1. Main/Torabinejad 2004 – Retrospective, Immediate MTA & Perforation Repair – 16/16 (100%) healed at 12-45 months post-repair with MTA: 5 lateral, 5 strip, 3 furcal, and 3 apical perforations




  1. Mente JOE 2010 - Retrospective, Immediate MTA root perf repair (Furcal, Crestal, Mid root, Apical root): Success: 18/21 (86%) healed at 1 year. No Predictors for success. Healed = No clinical/radiographic signs/symptoms, PAI  2.




  1. Krupp/Hulsman 2013 – Retrospective, MTA perf repair (90 teeth), Success: 73% at 1 year. Prognostic predictors: Pre-op RL associated w/ perforation and Sulcular communication with the perforation

Geristore & Perforation Repair


  1. Dragoo 1997 – Geristore (compomer) as a subgingival root repair material promoted healing with epithelial and connective tissue attachment




  1. Hammad/Al-Omairi 2011 – In vitro (rat CT implentation), GMTA>Geristore for severity of CT inflammatory reactions at 1 wk – 1 month




  1. Gupta 2013 – In vitro (cell culture), Geristore >MTA for viability & attachment of PDL fibroblasts


Post-Obturation

Should we use orifice sealers after obturation? What material ?


  1. Saunders IEJ 1997Vitrebond is an effective barrier for preventing microleakage in the pulpal floor.




  1. Wolcott JOE 1999 – Pigmented Vitrebond glass ionomer cement fulfills the criteria for an ideal barrier better than Ketac-bond or GC America barriers




  1. Wolanek JOE 2001Clearfil (composite) barrier showed no leakage, No barrier group showed positive bacterial penetration in 15 to 76 days. NOTE: Eugenol containing sealer had no effect on the bonding agent.

Do posts cause VRFs?


  1. Obermayr




  1. Peters – VRF from occlusal loading of posts




  1. Ross 1980 – Carbon fiber, Parallel sided posts least likely to cause VRFs




  1. Tamse/Fuss JOE 2001Etiology of VRFs: Post placement (Screw posts, tapered cast posts), Lateral condensation




  1. Dean/Jeansonne JOE 1998Carbon post/composite bu teeth had NO root fractures while parallel and tapered metal post groups had root fractures upon 45 deg loading


How much room should be left for a post space?


  1. Neagley OOO 1969 & Madison JOE 1984 - Agree that at least 4 mm of apical gutta percha should remain following post space preparation.




  1. Mattison J Prosthetic Dentistry 19845-6 mm of gutta percha is necessary for an adequate apical seal. Use rotary inst to remove GP.




  1. Goerig J Prosthetic Dentistry 1983 – Post should be 2/3 the length of the root and 10-15 mm in length, leaving at least 4-5 mm of gutta percha apically. Posts should be parallel and cemented, not screwed.




  1. Baba/Goodacre 2009: Leave 4-5 mm gutta percha for an apical seal


Posts & Ferrule:


  1. Nissan 2008 – When ferrule is 2mm, Post length is non contributory

Should you place a post immediately to avoid leakage?

YES

  1. Wu/Wesselink 1998; Metzger JOE 2000 –Both agree; Post prepared canals (apical 4mm gp) have inferior seal, post and core should be immediately completed after root canal treatment.




  1. Sato JOE 2002 & Fox IEJ 1997 - Both agree; Permanently cemented, prefabricated post and core produced the best seal; leakage was significantly greater with the temporary post/crown.




  1. Barrieshi/Walton – Obturated/post spaced prepared canals – unsealed – apical penetration by 90 daysrecommends immediate restoration




  1. Fan/Wu/Wesselink 1999 – Immed. Post space leaked less than delayed post space preparation

NO

  1. Lemon JOE 1981 – NSD in apical leakage with immediate vs delayed post space preparation.

What technique is best for making a post space?


  1. Todd 1983 J Prosthetic Dentistry – NSD between heat, Peeso, and Gates on apical seal. 4 mm apical seal is recommended for less leakage.




  1. Mattison 1990 J Prosthetic Dentistry – Significantly less leakage was observed with the heated plugger technique at the 3 mm and 5 mm levels when compared to both the GPX and the Gates-Glidden groups.



Does Ferrule affect root fracture?


  1. Sathorn 2005 - Inadequate ferrule increases chance of root fracture

  2. Tan 2005 – Uniform 2mm ferrule increases root resistance to fracture

  3. Nissan 2008 – When ferrule is 2mm, Post length is non contributory


Does eugenol in sealer affect the retention of the post?

YES

  1. Nemetz 1992Residual eugenol in the canal substantially decreased retention of Paraposts luted with Panavia composite resin cement. Irrigation with Ethyl Alcohol or Etching 37% phosphoric acid restored the retention.

NO

  1. Hagge IEJ 2002Kerr EWT, AH-26 and Sealapex did not affect the retention of endodontic posts luted with Panavia cement; therefore eugenol avoidance is unnecessary when selecting sealers.




  1. Schwartz/Walker 1998 JOEType of sealer (Roth’s or AH-26) had no effect on post retention with either cement (ZnPO4 or Panavia). Post retention was significantly greater with the zinc phosphate cement than the resin cement.




  1. Boone 2001 JOE – NSD in retention between types of sealer or post cementation times with Panavia. The mechanical removal of the sealer-impregnated dentin from the canal walls during post-space prepartation is a critical step in achieving optimum post retention when resin cement is used.

Does a post put stress on the tooth or cause tooth fractures?


  1. Tamse/Fuss 1999 – VRFs caused by posts, lateral condensation




  1. Peters – VRF from occlusal loading of posts




  1. Dean/Jeansonne JOE 1998Carbon post/composite bu teeth had NO root fractures while parallel and tapered post groups had root fractures upon 45 deg loading


What is in Cavit? What are it’s properties? Does it seal?


  1. Widerman JADA 1971 – Cavit has twice the linear expansion and half the compressive strength of ZOE; Composition of Cavit =

    1. Calcium sulfate

    2. Glycol acetate

    3. Triethanolamine

    4. Polyvinyl acetate

    5. Polyvinylchloride acetate

    6. Red pigment




  1. Webber 1978 OOO – A 3.5mm thickness of Cavit should be used in order to prevent leakage.




  1. Bobotis/Pashley 1989 JOE – Cavit, Cavit-G, TERM and glass ionomer cement provided leakproof seals during the 8 wk testing period. IRM did not.

What is in Cavit? What are it’s properties? Does it seal? Cont.


  1. Eleazer 2001 JOE – Cotton trapped between the wall of the tube and the filling material dramatically reduced the sealing quality of the temporary restoration.




  1. Stark 1990 OOO – Cavit had the best sealing ability, IRM showed the maximum dye penetration.




  1. Beach/Hutter JOE 1996 – Cavit provided a bacterial leakage-free seal for 3 wks.




  1. Mayer JOE 1997 – Cavit showed less leakage in the dye penetration test and fewer marginal crevices.




  1. Deveaus JOE 1999 – In-vitro leakage test – cavit leaked less than TERM, IRM, and Fermit.

Is Glass Ionomer superior to Cavit or IRM?

YES

  1. Barthel JOE 1999 – In vitro, Bacterial leakage (turbidity) study – Glass ionomer >> IRM > Cavit; At 30 days only G.I. prevented bacterial leakage




  1. Seiler AGD 2006 – In vitro, Bacterial leakage (turbidity) study – Glass Ionomer (GI) and Resin modified Glass Ionomer (RMGI) >> ZOE (IRM) for sealing capabilities


Is TERM superior to Cavit or IRM?

YES

  1. Anderson/Pashley 1989 – In vitro, fluid filtration study, Multisurface temporary restorations: TERM statistically superior seal compared with Cavit and IRM




  1. Bobotis/Pashley – In vitro, 8 wks fluid filtration, TERM = Cavit > IRM

Are Endodontically teeth more brittle ?


  1. Sedgley JOE 1992Vital dentin was 3.5% harder than endodontically treated dentin however the biomechanical properties of endo treated teeth and their contralateral vital pairs indicates that teeth do NOT become more brittle following endodontic treatment.




  1. Huang 1991 – Neither NSRCT nor dehydration decrease the tooth’s physical properties




  1. Papa/Messer - Dentinal moisture content: Vital teeth: 12.35%, Non-Vital teeth: 12.10%. NSDs




  1. Panitvisai – NSRCT teeth have greater cuspal deflection than those without


Is cuspal coverage important for endodontically treated posterior teeth?


  1. Aquilino/Caplan 2002 – Chart review - Endodontically treated teeth NOT crowned after obturation were lost at a 6.0x greater rate than teeth crowned after obturation




  1. Salehrabi/Rotstein – 97% Survival, 3% that did not were more often not crowned




  1. Linn 1994 JOE – Endodontically treated molars are considered susceptible to bulk fracture because of loss of tooth bulk. It is more important to cover cusps than to preserve tooth structure (including a marginal ridge) in endodontically treated molars.



Effect of Coronal Restoration/Leakage


  1. Ray/TropeCoronal seal more important than quality of RCT, Xray only,

Healed: GE/GR: 91.4%, PE/GR: 67.6%, GE/PR: 44.1%, PE/PR: 18.1%

  1. Gillen 2011Meta-analysis – 1 yr recall, Majority radiographic recall only. Odds ratios: AR/AE 2.8x more likely no AP than IR/AE, AR/AE 2.7x more likely no AP than AR/IE. Equal odds for healing with both scenarios.

  2. Ng – Quality of Coronal restoration Sig. effects success of NSRCT/RETX

  3. Swanson/Madison dye leakage, loss of coronal seal/coronal microleakage led to contamination of obturated canal w/in 3 days

  4. Khayat/Torbinejadbacterial leakage – No coronal seal, obturated - complete contamination of entire length w/in 30 days of loss of seal

  5. Magura/Newtondye leakage/histo eval - Recommends retreatment if exposed (or IRM remains) for 3 months (clinically significant leakage)

  6. Barrieshi/WaltonMixed anaerobic community developed/exposed to obturated/post space prepared canals – SEM analysis- apical penetration by 90 days - recommends immediate restoration of post space canal (Wu/Wess.)

Non-vital Bleaching. Does it cause resorption? How?


  1. Spasser 1961;Nutting/Poe – Sodium perborate – “walking bleach” technique: seal cotton pellet soaked in a mixture of Superoxol and Sodium perborate in the access cavity of the tooth for a period of 4 to 7 days. Superoxol is a strong oxidizing agent which breaks down the darkly pigmented macromolecules into smaller lighter colored molecules.




  1. Harrington/Natkin JOE 1979 – 7 cases of external cervical root resorpiton. Theory: Superoxol (+ heat) seeps through patent dentinal tubules and initiates an inflammatory resorptive response in the cervical area.




  1. Lado 1983 – Theory: 30% H2O2 denatures dentin exposed at the cervical margin, inciting an inflammatory response by clastic cells within the PDL.


Non-vital Bleaching. Does it cause resorption? How? Continued


  1. Cvek EDT 1985 – Theory: damage to the periodontium, caused by the bleaching agent at the time of treatment, may heal or be followed by ankylosis. When the situation is complicated by bacterial contamination of the gingival sulcus, progressive inflammatory changes in the periodontium is possible.




  1. Pathways of the Pulp Walking bleach results in cervical root resorption 6-8%, if heat is used to activate the superoxol the rate rises to 18-25% (Pathways).




  1. Madison & Walton JOE 1990 – Theory: resorption occurs when heat is used by driving the Superoxol through the dentinal tubules, thereby directly altering the cementum.


Non-vital Bleaching. Does it cause resorption? How? Continued


  1. Heithersay EDT 1997 Hydroxyl radical was generated after thermocatalytic bleaching w/ 30% H2O2. This radical may be one mechanism underlying PDL breakdown and resorption after bleaching.




  1. Rotstein - Internal bleaching & ECR – 30% H2O2 leakage through dentinal tubules at CEJ with no cemental layer – exposed mineralized dentin – damages dentin, initiates inflammation and external cervical root resorption




  1. Papadopoulos EDT 1996 – All CEJ junction types showed leakage of H2O2 from the chamber, but teeth with gaps (10%) at the CEJ had higher leakage values compared to the other 2 types.




  1. Neuvald JOE 2000 – CEJ Configuration of Cementum/Enamel joint – 60% overlap, 30% butt joint, 10% Gap

Regression of Internal Bleaching


  1. Ho/Goerig 1989 – 4% Color Regression after 6 months




  1. Abbott 2009 – 87% Good color change, 13% Acceptable color change; 4% Regression after one year



Success of Internal Bleaching


  1. Rotstein/Friedman JOE 1993 – Compared Internal bleaching prognosis of Sodium perborate + H2O vs Hydrogen Peroxide. Ex Vivo study, Sodium perborate mixed with: 30% H2O2, 3%H2O2, or H20. 1 year follow up. Results: Sodium perborate + H2O = Sodium perborate + 30% H2O2 (100% maintain color)


Preventing Resorption



  1. West JOE 1994 - Proposed the location and shape of an intracoronal bleach barrier




  1. Rotstein JOE 1992 – Bovine/human teeth – evaluated radicular penetration of 30% H2O2 based on thickness and material for barrier. Recommmends placing a 2 mm protective base (Glass ionomer) to the CEJ level to avoid radicular penetration of H2O2


Can You Bleach tetracycline stained teeth? (Intrinsic stain)


  1. Abou-Rass JOE 1982 – Found intentional RCT and internal bleaching is sometimes an effective treatment for tetracycline stains when other methods cannot be applied.




  1. Walton JOE 1982 – External bleaching is ineffective long term for tetracycline stains but internal bleaching is effective.


How does bleaching affect restoration of the tooth?


  1. Torneck JOE 1993 – Bond strength (resin polymerization) is adversely effected by bleaching




  1. Silva IEJ 2001 – Microleakage increased as a function of bleaching, short term use of CaOH2 after bleaching decreased microleakage

Retreatment


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