Root Canal Therapy
Root Canal Therapy (RCT)
The most widely used technique to treat
pulpal and periapical diseases
To remove the infected substances
To obturate canal in three dimension
Access opening
obtain access to the canal
2,clean and shape the canal
根管预备
3,intracanal medication
4,obturate the root canal
RCT procedures
1,Access opening
2,Root canal preparation
3,Intracanal medication
4,Root canal obturation
The primary objective of an access
opening is to provide straight line
access to the root canal system.
Step 1,ACCESS OPENING
Root Canal Preparation
Step 2:
1,Objective
2,Instruments
3,Working length
4,PAF and MAF
5,Irrigation
6,Instumentation technique
1,Objective of root canal preparation
Cleaning
Shaping
Cleaning
? Remove all organic debris from root
canal system
? Eliminate bacteria from the root canal
Shaping
obturation of the canals
Irrigation of the canals
2,Endodontic instruments for
cleaning and shaping
Hand
–files
–reamers
–broaches
Rotary
–Gates-Glidden
-Nickel titanium
Instrument types
K reamer
扩孔钻
K file
K 锉
Flex0file
K Flex
H file
H 锉
Unifile
0.5 ~ 1个切嵴 /mm
(10~30 度角）
1.5~2.5个切嵴 /mm
(25~40 度角）
？个切嵴 /mm
(60~65 度角）
Anatomy of ISO instrument
for cutting
D1,a point at the beginning of the tip
D2,a point at the end of the blades
Length between D1 and D2 is 16mm
Length of working part
shaft
handle
The numbering system:
Diameter of D1 in hundredths of a millimeter
Size 10,The diameter of the tip is 0.1mm
Size 55,The diameter of the tip is 0.55mm
For example:
Colour coding system
white yellow red blue green black
15 20 25 30 35 40
45 50 55 60 70 80
90 110 120 130 140 150
06 pink
08 grey
10 Purple
taper,0.02mm/mm
10mm
11mm
12mm
13mm
a
b
c
dX=1mm
Taper = d – c / X
= (13 – 12) /1
= 1
The full length of the instrument:
Standard,25mm Short:21mm
Long,31mm
A thin,flexible,fragile pointed metal
instrument with sharp projections
curving backwards
to remove pulp tissue or other easily
engaged materials from the pulp canal
Barbed Broach
Rotary instrumentation
Rotary burs are essential for root canal
shaping/Flaring,
Rotary files have made a significant
leap forward with the advent of
Nickel-titanium,
Root canal preparation will always
require a skillful clinician and hand
files.
Gates-Glidden Burs
Used in a low-speed hand-piece for opening
canal orifices and coronal root canal
preparation,
It is self-centering,therefore care must be taken
to avoid thinning the furcation wall of canals,
Designed to break away from the tip,making
for easy retrieval.
GG Burs diameter
#1=.50 mm
#2=.70 mm
#3=.90 mm
#4=1.10 mm
#5=1.30 mm
#6=1.50 mm
3,Working Length
The distance from a coronal reference
point to the point at which canal
preparation and obturation should
terminate,
Clinically,the working length landmark is at the apical
constriction,Usually 0.5-1.0mm short of the apical
foramen,
Where is
APICAL CONSTRICTION
Methods for WL
Tactile
Radiographic
Electric
Once the coronal 2/3 have been shaped,
the experienced clinician can detect a
sudden rise in resistance as the file
approaches the apex,
Tactile
橡皮片
Rubber stop
Reference point
If the trial length is within 1.5mm
from the working length,make the
correction and proceed,
Otherwise,adjust the length and take
a new working length radiograph.
Electric Measurement
不同设计的根尖定位仪的准确性比较
定位仪 测量准确性
阻抗型 (第一,二代 )
Endex(差值型 )
Root ZX(比值型 )
55%-75%
89.64%
96.20%
1990 Fouad AF,1993 Frank AL,1998 Pagavino G,1996 Shabahang S
(解剖根尖孔内 0.5mm)
根尖孔直径 0.9mm
Root ZX 测量 X线片测量
4,Primary apical file (PAF) and
Maxiamum apical file MAF)
PAF is the minimum apical file which
can bind at the apical constriction
MAF should be 3 sizes larger than PAF
Step back N
D ebris s cor e
x ? s
mesial 35 15 0.46 ? 0.54
mesial 60 15 0.20 ? 0.40
P < 0.01
Cleanness after step back instrumentation
(Lumley,Int Endod J 2000;33:262-5)
Trope M,Ray HL,Oral Surg
1992; 73:99-102.
The resistance to fracture will be
reduced by 33% after using GG #3
Procedures error,ledge,transportation,peforation
5,Irrigation
Goals of irrigation
Lavage debris
Tissue dissolution
Antibacterial action
lubrication
Irrigation solutions:
Sodium Hypochloride
Hydrogen peroxide
NaCl
EDTA
Ultrasound irrigation
Stock,Int Dent J 1991;
41:175-82
Debris Without debris
Lee SJ,Wu MK,Wesselink PR,The efficacy of ultrasonic irrigation to remove
artificially placed dentine debris from different-sized simulated plastic root
canals,Int Endod J,2004 Sep;37(9):607-12
After ultrasonic irrigation,the debris score for the size
20,.04 taper group was significantly higher than that for
the size 20,.06 group (P = 0.040) and the size 20,.08 group
(P = 0.006) groups
6,Instrumention technique
(1) Standard method
(2) Step-back technique
(4) Step-down preparation;
Crown down pressureless technique
(3) Modified double-flare preparation
(5) NiTi instrumentation
Standardized technique
The taper is only 2% after preparation
When taper is larger than 4% ( 4% ~12%),
the canal shape is suitable for obturation
2% 10 %5%
Step back technique
逐步后退法
Apical preparation
Step back
Flaring coronal part
Crown-down technique (根向预备技术 )
Intracanal Medication
Step 3:
To eliminate the remaining bacteria;
To provide a barrier against leakage;
To reduce inflammation
Calcium hydroxide is recommended
Objectives of intracanal medication
Enimilate the bacteria
Dissolve the remaining pulp tissue
Encourage the deposition of hard tissue
Calcium Hydroxide
Medication
Obturation
Step 4:
1,Objectives
2,Pre-requisites
3,Materials
4,Instruments
5,Obturation technique
To eliminate leakage of irritants from the
oral cavity and/or periapical tissues into the
root canal system
To seal in irritants that cannot be removed
during cleaning and shaping
Irritants,Microbial,Products of pulp tissue
degeneration,Toxins
? Objectives of obturation
Pre-requisites
? Tooth properly isolated to eliminate
canal contamination during obturation
? Canal system cleaned,shaped and dried
? Absence of significant signs and
symptoms
Root canal filling materials
Most commonly used Materials
for root canal obturation
Gutta percha points
Root canal Sealer
root canal sealer
Obturation
? Objectives of obturation
? Pre-requisites
? Root canal filling materials
? Instruments for obturation
? Obturation techniques
Spreader
Plugger
Instruments for obturation
Spreader
Plugger
Tips are pointed
Hand spreaders eg,GP3,D11T,
D11S
Finger spreaders eg,#25
Spreaders
Obturation techniques
Methods of obturation
? Lateral condensation
? Vertical condensation
? Solid core carrier insertion
? Thermoplastic injection
? Mechanic obturation
? Continuous wave condensation
? Microseal technique
? NIT technique
Lateral condensation is the standard
method and should be mastered before
learning other methods
Involves the compaction of the primary master
cone and sealer against the apical foramen
Condensing additional accessory gutta percha
cones alongside the master cone fills the
remainder of the canal
What is lateral compaction?
A,Fit master cone
B,Make a space with spreader
C,Add accessory cones until canal
obturated
Procedures
1,选择合适的侧向加压器 2,试尖
? Load sealer on file (one size smaller
than MAF);
? Place into canal (1mm short from WL);
? Rotate file counterclockwise while
withdrawing
? Do not flood the canal with sealer
Sealer placement
3,涂根管封闭剂
Coat apical 5mm of master cone with
sealer
Insert master cone slowly to working
length in order to allow air and sealer
to escape
Master cone placement
4,插入主牙胶尖
Insert marked spreader between master
cone and canal wall to within 1 mm short
of WL;
The pressure exerted is directed along
long axis of tooth and should not exceed
5lb ;
The taper of spreader creates the lateral
force
Using the spreader
5,侧向加压 6,插入补充尖
Place accessory cone in created
space
Repeat until spreader can be
advanced no more than 2-3 mm into
the canal beyond the CEJ
Accessory cone placement
Sear the excess GP off with a heated
instrument to level of CEJ
Using cool end of plugger vertically
condense gutta percha at orifice
Take radiograph before removing rubber
dam
Finishing
7,切断根管口的牙胶尖 8,垂直加压
Pre-fill Post-fill
Radiolucencies,Are there voids,
indicating incomplete obturation?
Density,Is there uniform density from
coronal to apical?
Length,Does material extend to WL?
Shape,Does fill reflect shape of the canal,
tapered from coronal to apical?
Radiographic evaluation of obturation
Overfill implies a 3D fill that is too long
Overextension is underfilled (not 3D) and
long.
Overfill versus overextension
–An incomplete obturation of the root
canal space with resultant voids
Reason:
–Inadequate taper in preparation
–Improper spreader/cone placement
Underfill
Schilder 1975
Ruddle 1992
Vertical Condensation
1,Plugger trial
垂直加压器
2,GP trial
Non ISO GP
Heat carrier
3,Obturate lateral canals in coronal part
4,Obturate lateral canals in middle part
5,Obturate canal in apical part
6,Obturate main canal in middle part
7,Obturate canal in coronal part
Thermafil obturation
pre-op
Rubber dam
Working length
Step back preparation
MAF
ultrasonic
Coating sealer
Thermafil insertion
sear Thermafil
Post op
3m after treatment
THANKS
Root Canal Therapy (RCT)
The most widely used technique to treat
pulpal and periapical diseases
To remove the infected substances
To obturate canal in three dimension
Access opening
obtain access to the canal
2,clean and shape the canal
根管预备
3,intracanal medication
4,obturate the root canal
RCT procedures
1,Access opening
2,Root canal preparation
3,Intracanal medication
4,Root canal obturation
The primary objective of an access
opening is to provide straight line
access to the root canal system.
Step 1,ACCESS OPENING
Root Canal Preparation
Step 2:
1,Objective
2,Instruments
3,Working length
4,PAF and MAF
5,Irrigation
6,Instumentation technique
1,Objective of root canal preparation
Cleaning
Shaping
Cleaning
? Remove all organic debris from root
canal system
? Eliminate bacteria from the root canal
Shaping
obturation of the canals
Irrigation of the canals
2,Endodontic instruments for
cleaning and shaping
Hand
–files
–reamers
–broaches
Rotary
–Gates-Glidden
-Nickel titanium
Instrument types
K reamer
扩孔钻
K file
K 锉
Flex0file
K Flex
H file
H 锉
Unifile
0.5 ~ 1个切嵴 /mm
(10~30 度角）
1.5~2.5个切嵴 /mm
(25~40 度角）
？个切嵴 /mm
(60~65 度角）
Anatomy of ISO instrument
for cutting
D1,a point at the beginning of the tip
D2,a point at the end of the blades
Length between D1 and D2 is 16mm
Length of working part
shaft
handle
The numbering system:
Diameter of D1 in hundredths of a millimeter
Size 10,The diameter of the tip is 0.1mm
Size 55,The diameter of the tip is 0.55mm
For example:
Colour coding system
white yellow red blue green black
15 20 25 30 35 40
45 50 55 60 70 80
90 110 120 130 140 150
06 pink
08 grey
10 Purple
taper,0.02mm/mm
10mm
11mm
12mm
13mm
a
b
c
dX=1mm
Taper = d – c / X
= (13 – 12) /1
= 1
The full length of the instrument:
Standard,25mm Short:21mm
Long,31mm
A thin,flexible,fragile pointed metal
instrument with sharp projections
curving backwards
to remove pulp tissue or other easily
engaged materials from the pulp canal
Barbed Broach
Rotary instrumentation
Rotary burs are essential for root canal
shaping/Flaring,
Rotary files have made a significant
leap forward with the advent of
Nickel-titanium,
Root canal preparation will always
require a skillful clinician and hand
files.
Gates-Glidden Burs
Used in a low-speed hand-piece for opening
canal orifices and coronal root canal
preparation,
It is self-centering,therefore care must be taken
to avoid thinning the furcation wall of canals,
Designed to break away from the tip,making
for easy retrieval.
GG Burs diameter
#1=.50 mm
#2=.70 mm
#3=.90 mm
#4=1.10 mm
#5=1.30 mm
#6=1.50 mm
3,Working Length
The distance from a coronal reference
point to the point at which canal
preparation and obturation should
terminate,
Clinically,the working length landmark is at the apical
constriction,Usually 0.5-1.0mm short of the apical
foramen,
Where is
APICAL CONSTRICTION
Methods for WL
Tactile
Radiographic
Electric
Once the coronal 2/3 have been shaped,
the experienced clinician can detect a
sudden rise in resistance as the file
approaches the apex,
Tactile
橡皮片
Rubber stop
Reference point
If the trial length is within 1.5mm
from the working length,make the
correction and proceed,
Otherwise,adjust the length and take
a new working length radiograph.
Electric Measurement
不同设计的根尖定位仪的准确性比较
定位仪 测量准确性
阻抗型 (第一,二代 )
Endex(差值型 )
Root ZX(比值型 )
55%-75%
89.64%
96.20%
1990 Fouad AF,1993 Frank AL,1998 Pagavino G,1996 Shabahang S
(解剖根尖孔内 0.5mm)
根尖孔直径 0.9mm
Root ZX 测量 X线片测量
4,Primary apical file (PAF) and
Maxiamum apical file MAF)
PAF is the minimum apical file which
can bind at the apical constriction
MAF should be 3 sizes larger than PAF
Step back N
D ebris s cor e
x ? s
mesial 35 15 0.46 ? 0.54
mesial 60 15 0.20 ? 0.40
P < 0.01
Cleanness after step back instrumentation
(Lumley,Int Endod J 2000;33:262-5)
Trope M,Ray HL,Oral Surg
1992; 73:99-102.
The resistance to fracture will be
reduced by 33% after using GG #3
Procedures error,ledge,transportation,peforation
5,Irrigation
Goals of irrigation
Lavage debris
Tissue dissolution
Antibacterial action
lubrication
Irrigation solutions:
Sodium Hypochloride
Hydrogen peroxide
NaCl
EDTA
Ultrasound irrigation
Stock,Int Dent J 1991;
41:175-82
Debris Without debris
Lee SJ,Wu MK,Wesselink PR,The efficacy of ultrasonic irrigation to remove
artificially placed dentine debris from different-sized simulated plastic root
canals,Int Endod J,2004 Sep;37(9):607-12
After ultrasonic irrigation,the debris score for the size
20,.04 taper group was significantly higher than that for
the size 20,.06 group (P = 0.040) and the size 20,.08 group
(P = 0.006) groups
6,Instrumention technique
(1) Standard method
(2) Step-back technique
(4) Step-down preparation;
Crown down pressureless technique
(3) Modified double-flare preparation
(5) NiTi instrumentation
Standardized technique
The taper is only 2% after preparation
When taper is larger than 4% ( 4% ~12%),
the canal shape is suitable for obturation
2% 10 %5%
Step back technique
逐步后退法
Apical preparation
Step back
Flaring coronal part
Crown-down technique (根向预备技术 )
Intracanal Medication
Step 3:
To eliminate the remaining bacteria;
To provide a barrier against leakage;
To reduce inflammation
Calcium hydroxide is recommended
Objectives of intracanal medication
Enimilate the bacteria
Dissolve the remaining pulp tissue
Encourage the deposition of hard tissue
Calcium Hydroxide
Medication
Obturation
Step 4:
1,Objectives
2,Pre-requisites
3,Materials
4,Instruments
5,Obturation technique
To eliminate leakage of irritants from the
oral cavity and/or periapical tissues into the
root canal system
To seal in irritants that cannot be removed
during cleaning and shaping
Irritants,Microbial,Products of pulp tissue
degeneration,Toxins
? Objectives of obturation
Pre-requisites
? Tooth properly isolated to eliminate
canal contamination during obturation
? Canal system cleaned,shaped and dried
? Absence of significant signs and
symptoms
Root canal filling materials
Most commonly used Materials
for root canal obturation
Gutta percha points
Root canal Sealer
root canal sealer
Obturation
? Objectives of obturation
? Pre-requisites
? Root canal filling materials
? Instruments for obturation
? Obturation techniques
Spreader
Plugger
Instruments for obturation
Spreader
Plugger
Tips are pointed
Hand spreaders eg,GP3,D11T,
D11S
Finger spreaders eg,#25
Spreaders
Obturation techniques
Methods of obturation
? Lateral condensation
? Vertical condensation
? Solid core carrier insertion
? Thermoplastic injection
? Mechanic obturation
? Continuous wave condensation
? Microseal technique
? NIT technique
Lateral condensation is the standard
method and should be mastered before
learning other methods
Involves the compaction of the primary master
cone and sealer against the apical foramen
Condensing additional accessory gutta percha
cones alongside the master cone fills the
remainder of the canal
What is lateral compaction?
A,Fit master cone
B,Make a space with spreader
C,Add accessory cones until canal
obturated
Procedures
1,选择合适的侧向加压器 2,试尖
? Load sealer on file (one size smaller
than MAF);
? Place into canal (1mm short from WL);
? Rotate file counterclockwise while
withdrawing
? Do not flood the canal with sealer
Sealer placement
3,涂根管封闭剂
Coat apical 5mm of master cone with
sealer
Insert master cone slowly to working
length in order to allow air and sealer
to escape
Master cone placement
4,插入主牙胶尖
Insert marked spreader between master
cone and canal wall to within 1 mm short
of WL;
The pressure exerted is directed along
long axis of tooth and should not exceed
5lb ;
The taper of spreader creates the lateral
force
Using the spreader
5,侧向加压 6,插入补充尖
Place accessory cone in created
space
Repeat until spreader can be
advanced no more than 2-3 mm into
the canal beyond the CEJ
Accessory cone placement
Sear the excess GP off with a heated
instrument to level of CEJ
Using cool end of plugger vertically
condense gutta percha at orifice
Take radiograph before removing rubber
dam
Finishing
7,切断根管口的牙胶尖 8,垂直加压
Pre-fill Post-fill
Radiolucencies,Are there voids,
indicating incomplete obturation?
Density,Is there uniform density from
coronal to apical?
Length,Does material extend to WL?
Shape,Does fill reflect shape of the canal,
tapered from coronal to apical?
Radiographic evaluation of obturation
Overfill implies a 3D fill that is too long
Overextension is underfilled (not 3D) and
long.
Overfill versus overextension
–An incomplete obturation of the root
canal space with resultant voids
Reason:
–Inadequate taper in preparation
–Improper spreader/cone placement
Underfill
Schilder 1975
Ruddle 1992
Vertical Condensation
1,Plugger trial
垂直加压器
2,GP trial
Non ISO GP
Heat carrier
3,Obturate lateral canals in coronal part
4,Obturate lateral canals in middle part
5,Obturate canal in apical part
6,Obturate main canal in middle part
7,Obturate canal in coronal part
Thermafil obturation
pre-op
Rubber dam
Working length
Step back preparation
MAF
ultrasonic
Coating sealer
Thermafil insertion
sear Thermafil
Post op
3m after treatment
THANKS
