BY DR.TAMALE FRED

1. TOOTH ISOLATION
AND MATERIALS USED
IN ENDODONTICS
Makerere University
BDS IV

2. Materials used in endodontics

3. MATERIALS USED
 Irrigants and lubricants –used during canal preparation
 Intracanal medicaments –maintain canal in disinfected
state
 Obturating materials
 Used during endodontic surgery and repair

4. IRRIGANTS AND LUBRICANTS
Functions of irrigants
Used to flush debris from the root canal
 Disinfect the canals
 Lubrication of instruments used to shape canals
 Opening dentinal tubules by removal of smear layer
 Dissolve necrotic tissue
PROPERTIES
Able to dissolve tissues and debris
Non toxic
Low surface tension
Able to remove smear layer
Able to sterilize or disinfect
Able to lubricate instruments
Broad spectrum antimicrobial properties

5. Factors that affect activity of
irrigating solutions
 Concentration
 Contact
 Presence of organic tissue
 Quantity of irrigant used
 Gauge of the needle
 Surface tension of irrigant
 Temperature of the irrigant
 Frequency of irrigation
 Canal diameter
 Age of irrigant

6. EXAMPLES
Chemically non active solutions
 Water, normal saline , local anesthetic solutions
Chemically active material
 Alkalis; sodium hypochlorite 0.5-5.25%
 Chelating agents ; EDTA, citric acid ,
 Oxidising agents ; Hydrogen and carbamide peroxide
 Antibacterial agents; chx, bisdequalinium acetate
 Acids ; 30% hydrochloric acid
 Enzymes ;streptokinase , papain, trypsin

7. Sodium hypochlorite
 0.5-5.25%
 Antibacterial and antifungal
 Excellent tissue dissolvinging ability
 Effectiveness introduced by increasing temperature to
around 60-70
 Apical reaction
 Adverse effects on mechanical properties of dentine
 Needs Rubber dam to prevent injury to soft tissues

8. Mechanism of action of
NaOCL
Ionises in water to form sodium ions and hypochlorite ions,
that establishes an equlibrium with hypochlorous acid.
Between PH 4-7 chlorine exists predominately as
hypochlorous ,the active moeity while above PH 9 it exists
as hypochlorite(less effective)
It is the hypochlorous moeity that is responsible for in
activation of bacteria by disrupting oxidative
phosphorylation and DNA synthesis

9. Advantages
 it causes dissolution of pulpal remnants
 Causes dissolution of organic components
 Antibacterial and bleaching action
Disadvantages
 Can be corrossive
 Bad odour and taste
 Can cause inflammation of gingiva
 Irritant to tissues if extruded periapically


10. Hydrogen peroxide
Clear , odourless liquid
3%-30% concentration available
3% solution is used as an irrigant
Mechanism of action
it rapidly dissociates into water and oxgyen ,on coming in
contact with tissue enzymes catalase and peroxidase, the
liberated oxygen produces bacteriacidal effect
Rapid release of oxygen on contact with organic tissue
results in bubbling action which aids in mechanical
debridement by dislodging particles of necrotic tissue and
dentinal debris

11. Chlorhexidine
 Most potent bisguanide
 Optimal antimicrobial action at PH 5.5-7.0
 2% concentration is used in irrigation
 Plaque control activity of 0.2%
 Broad spectrum anti microbial
 Bacterial static at low concentration and
bactericidal at high concentration
 More effective on gram postive than gram
negative

12. Mechanism of action
2% Chlorhexidine digluconate is capable of electrostatically binding to
negatively charged bacterial surfaces.
The antimicrobial activity of CHX against gram-positive bacteria and
yeasts is attributed to its ability to permeate the microbial cell wall
and cause coagulation of the cytoplasmic components.
Moreover, CHX is very effective against E. faecalis, which is one of the
most common Pathogens identified in root canal–filled teeth exhibiting
clinical failure.
The most important clinical characteristic of chlorhexidine is its
substantivity, which refers to its sustained action within the root
canal.

13. Limitations of CHX
 CHX lacks tissue-dissolving ability.
 It does not remove the smear layer and hence has to be
employed in conjunction with other irrigants
 Stains teeth

14. Chelating agents
EDTA
Chelating agent
Contains four acetic acid groups attached to ethylenediamine
Has little anti bacterial activity
However on direct exposure for extended time EDTA releases bacterial surface
proteins by combining with metal ions from cell envelope leading to bacterial
death
It is non toxic
functions
Lubrication
Emulsification
Smear layer removal when used together with HOCl by acting on inorganic
component dentin.

15.  Mechanism of action
Inhibits growth of bacteria and ultimately
destroys them by starvation because EDTA
chelates with metalic ions in medium which are
needed for growth of microorganisms
It forms a stable bond with calcium and dissolve
dentine, but when all chelating ions have reacted
, an equilibrium is reached which prevents
further dissolution

16. Uses of EDTA
Dentine dissolving properties
Enlarges canals
Reduces time needed for debridement
Forms of EDTA
R-EDTA
EDTAT-C
EDTAT
RC PREP
OTHER CELATING A GENTS INCLUDE ; citric acid ,
polyacrylic acid

17. MTAD
Composition
 Tetracycline:
 It is bacteriostatic broadspectrum antibiotic
 It has low pH and acts as calcium chelator
 It removes smear layer
 It has property of substantivity
 It promotes healing.
 Citric acid: It is bactericidal in nature and removes
smear layer.
 Detergent (Tween 80): It decreases surface tension.

18. Properties of MTAD
 It is an effective solution for removal of most of the smear
layer.
 It kills most significant bacterial stains, i.e. E. faecalis
which has been shown to resistant to many intracanal
medicaments and irrigants
 It is biocompatible
 It has minimal effect on properties of teeth
 MTAD has similar solubilizing effects on pulp and dentin to
those of EDTA

19.  IMPORTANT
Irrigants should be used in large volumes and never
delivered with excessive force

20. INTRACANAL MEDICAMENTS
 A medicament is an anti microbial a gent that is placed
inside the root canal between treatment appointments in
an attempt to destroy microorganisms and prevent
infection
FUNCTIONS
Primary –anti microbial, antisepsis, disinfection
Secondary –hard tissue formation, pain control, exudation
control, resorption control

21. PROPERTIES
 Anti bacterial
 Penetrates dentinal tubules
 Biocompatible
 Eliminate pain
 Radio opaque
 Should not stain teeth
 Induce calcific barrier control exudation and
bleeding

22. Indications of intracanal
medicaments
 ƒTo dry persistently wet or the so-called weeping canals
 ƒƒTo eliminate any remaining microbes in the pulp space
 ƒƒTo render root canal contents inert
 ƒƒTo neutralize tissue debris
 ƒƒTo act as a barrier against leakage from an
interappointment dressing in symptomatic cases

23. Calcium hydroxide
Available in powder and paste form
Functions
 Inhibits root resorption
 Stimulates periapical healing
 Encourages mineralization
Indications
 Weeping canals
 Treatment of phoenix abscess
 For apexification
 During pulpotomy
 As sealer for obturation
 To decrease postoperative pain after over instrumentation,
it is used in combination with Ledermix

24. Mechanism of action of
Ca(OH)2
 Damaging the cytoplasmic membrane
 Protein denaturation
 Damaging bacterial DNA

25. Effects of calcium hydroxide
 Physical;-acts as a physical bacteria for ingress of
bacteria
 Destroys the remaining bacteria by limiting space for
multiplication
 Chemical;-it shows antiseptic action because of its high
PH
 -inhibits DNA replication
 -suppresses enzymatic activity and disrupts cell
membrane

26. Essential oils
 Eugenol
Chemical essence of clove oil effects depend on tissue
concentrations of eugenol
Anti-inflamatory activity – low doses
Cytotoxic effects- high doses
Uses
Intracanal medicament
Root canal sealer
Temporary sealing agent

27. aldehydes
 Formaldehyde, paraformaldehyde and glutaraldehyde
are commonly used intracanal medicaments in root canal therapy.
• These are water-soluble protein denaturing agents and are
considered among the most potent disinfectants.
• They are mainly applied as disinfectants for surfaces and
medical equipment which cannot be sterilized, but they are quite
toxic and allergic and some even may be carcinogenic

28. Formocresol
 Formocresol contains formaldehyde as its main ingredient and is still widely
used medicament for pulpotomy procedures in primary teeth but its toxic
and mutagenic properties are of concern .
Composition of formocresol
• Formaldehyde — 19%
• Cresol — 35%
• Water and glycerine — 46%
Uses: Used as dressing for pulpotomy to fix the retained pulpal tissue.
Paraformaldehyde
• It is polymeric form of formaldehyde and is commonly found as component of
some root canal obturating material like endomethasone.
• It slowly decomposes to give out formocresol, its monomer.
• Its properties are similar to formaldehyde that is toxic, allergenic and
genotoxic in nature

29. Phenolic compounds
Phenol
Liquefied phenol (Carbolic acid) consists of 9 parts of phenol and 1 part of water.
Uses
• It is used for disinfection before periapical surgery.
• It is also used for cauterizing tissue tags that resist removal with broaches or
files.
Parachlorophenol
Composition
2parts of parachlorophenol+3 parts of camphor
CAMPHOR IS ADDED BECAUSE;
• Has diluent action
• Prolongs the antimicrobial effect
• Reduces the irritating effect of PCP
• Serves as a vehicle for the solution.

30. Materials used in obturation
Requirements of a good obturating material
 ƒThe material should be easily introduced into the root canal.
 ƒƒIt should seal the canal laterally as well as apically.
 ƒƒIt should not shrink after being inserted.
 ƒƒIt should set slowly.
 ƒƒIt should be impervious to moisture.
 ƒƒIt should be bactericidal or, at least, should discourage the growth of
bacteria.
 ƒƒIt should be radiopaque.
 ƒƒIt should not stain the tooth structure.
 ƒƒIt should not irritate periradicular tissues or affect the tooth structure.
 ƒƒIt should be sterile, or easily and quickly sterilized immediately before
insertion.
 ƒƒIt should be easily removable from the root canal

31. Obturation materials
 Conventional materials
SILVER- used inform of prefabricated cones
- not fit to anatomy of root canals, it also undergoes corrosion
 ŠSilver cones are no longer recommended in endodontic practice.

32. Currently used core materials in
obturation
GUTTA PERCHA
Composition ;- ƒ
 20% gutta-percha (matrix)
 ƒƒ66% zinc oxide (filler)
 ƒƒ11% heavy-metal sulfates (radiopacifier)
 ƒƒ3% waxes or resins (plasticizer)
Available in different sizes
 Extra fine
 Fine
 Medium fine
 Fine medium
 Medium
 Large
 Extra large

33. Properties of GUTTAPERCHA
 It does not shrink after insertion unless it is plasticized
with a solvent or heat.
 It is easily sterilized prior to insertion and does not
encourage bacterial growth.
 It is radiopaque, nonstaining, and impervious to
moisture.
 It can be removed easily from the root canal if
necessary.
 It is probably the least toxic and least irritating root
canal filling material.

34.  RESILON
Alternative to guttapercha
 Composition;- It is a polycaprolactone core material with
difunctional methacrylate resin, bioactive glass, bismuth
and barium salts as fillers, and pigments.

35. MTA(mineral trioxide
aggregate)
 Can be used as obturation material as well as canal
sealant because of its superior physiochemical and
bioactive properties
 Indications -MTA obturation combined with root-end
resection
 Teeth with open apices
 Internal resorption
Dens in dente

37. TYPES OF MTA
 Grey MTA
Contains tricalcium aluminoferrite which is
responsible for the grey colour so it cannot be used
for anterior teeth
Has larger particles
Longer setting time
Greater compressive strength

38.  White MTA
Ferrous oxide is replaced magnesium oxide so no
discolouration
Smaller particle size
Shorter setting time
Less compressive strength

39. PROPERTIES OF MTA
 Compressive strength –it takes 3hrs for mta to solidify,
has compressive strength equal to IRM and EBA but less
than amalgam
 PH-has initial ph of 10.2 which rises to 12.5 after 3hrs
after mixing
 Radiopacity-less radiopaque compared to EBA, amalgam
and IRM
 Solubility –no sign of solubility though solubility may
increase if more water is used in mixing

40.  Marginal adaptation MTA expands during
setting making excellent in the sealing
ability
 Antibacterial and anti fungal mta has
antibacterial and anti fungal properties
especially against E.feacalis
 Biocompatibility less cytotoxic and not
mutagenic
 Tissue regeneration-capable of activation of
cementoblasts and production of cementum,
facilitates regeneration of PDL, allows bone
healing

41. Limitations of MTA
 Difficulty in retreatment following
MTA obturation, especially in curved
canals
 Potential for discoloration,
especially when used in the anterior
esthetic zone

42. ROOT CANAL SEALERS
properties
 Antimicrobial agent
 Binding agent
 As lubricant.
 Radiopacity

43.  Materials used as sealants
ZINC OXIDE EUGENOL(grossmanns formula)
composition- ZnO, stabellite resin, bismuth subcarbonate,
barium sulfate, sodium borate, liquid eugenol
RESIN BASED SEALANTS-
Composition- liquid epoxy bisphenol resin
Powder bismuth oxide 60%, hexamethylene triamine 25%,
silver 10%

44. ISOLATION
Provides comfort to patient
• Protects patients from swallowing or aspirating foreign bodies
• Protects patient’s soft tissues—tongue, cheeks by retracting
them from operating field.
Operator related factors:
• A dry and clean operating field
• Infection control by minimizing aerosol production
• Increased accessibility to operative site
• Improved properties of dental materials, hence better results
are obtained
• Protection of the patient and operator
• Improved visibility of the working field and diagnosis.
• Less fogging of the dental mirror
• Prevents contamination of tooth preparation
• Hemorrhage from gingiva does not enter operative site

45. Isolation with a rubber dam
 Thin sheet of metarial applied to isolate teeth during
treatment
 Made of latex or non latex material
 Develoveped in 19th century by barnum

46. Why use a rubber dam?
 Provides a clean dry disinfected field
 Protects patients from
-aspiration of instruments
-patients from drugs and irrigating solutions
-clinician –minimizing risk of cross contamination
-clinician from litigation in case a patient swallows
instruments
 Improves visibility
 Increases effeciency
 Soft tissue retraction

47. Components of rubber dam
 Rubber dam material
Thin, flat sheet of latex into which holes are punched for
teeth to be exposed during treatment
Pre cut:two sizes 5х5 inches and 6х6
Rolls cut by a physcian
Various colours (yellow,blue, green)

48.  Rubber dam frame
Designed to retract and stabilize the dam
Metal/plastic frames

49.  Rubber dam retainer/clamp
Anchor the dam to tooth requiring treatment
Made of stainless steel
Aid in soft tissue retraction
Each camp consists of bow and two jaws
Winged or wingless

50.  Availabe from various manufactures
 Designed for all classes of teeth
 Basic uncomplicated procedures
Butterfly clamp for anterior
Universal premolar clamp
Mandibular molar clamp
Maxillary molar clamp

51.  Complicated cases
Minimal coronal tooth structure-clamps with apically
inclined jaw, clamps with serrated jaw
Severely broken tooth- silver glickman clamp

52.  Rubber dam punch
Used to create hole in the dam
Has a series of holes on a rotating disc
Holes are selected according to size of tooth

53.  Rubber dam forceps
Holds and caries the retainer during placement

54. Methods of rubber dam placement
 One step techinique
Rubber dam, clamp and frame
Attach dam to frame, position clamp in the dam, hold clamp with rubber forceps
Dam clamp and frame placed over tooth as one unit
Tuck rubber and wings

55.  Two step technique
A clamp placed first, dam attached to frame gently
stretched over the clamp
Clamp is tested to ensure no rocking

56. END