1. DEPARTMENT OF CONSERVATIVE DENTISTRY &
ENDODONTICS
SEMINAR TOPIC
ENDODONTIC MISHAPS
Presented by :
SUKESH
KUMAR

2. Batch : 2007-08
INTRODUCTION:
 ARE THOSE UNFORTUNATE OCCURRENCE THAT
HAPPENS DURING THE TREATMENT,SOME OWING TO
INATTENTION TO DETAIL,OTHERS TOTALLY
UNPREDICTABLE.
 CLASSIFICATION:
1)ACCESS OPENING OF PULP SPACE
2)IN CANAL CLEANING & SHAPING
3)OBTURATION RELATED
4)MISCELLANEOUS
PROCEDURAL ERRORS RELATED TO ACCESS
OPENING
 PROPER ACCESS OPENING IS KEY TO ENSURE AN
ERRORLESS PROCEDURE DURING CLEANING &
SHAPING.IF NOT GAINED,IT WOULD BE BEGINNING OF
PROCEDURAL FAILURE.
 PRE-OPERATIVE RADIOGRAPHS WHICH PROVIDES
VITAL INFORMATION ABOUT THE ROOTCANAL
CONFIGURATION,CALCIFICATION SHOULD BE ABLE TO
READ THE RADIOGRAPHS.

3.  VISUAL ENHANCEMENT AIDS LIKE DENTAL
OPERATING MICROSCOPE(DOM) NOT ONLY HELPFUL
IN CHALLENGING CASES BUT ARE ALSO
RECOMMENDED ROUTINELY TO ENSURE HIGHEST
LEVEL OF ENDODONTIC CARE
.MAIN ERRORS DURING ACCESS OPENING ARE:
1)TREATING WRONG TOOTH
2)INCOMPLETE CARIES REMOVAL.
3)ACCESS OPENING THROUGH FULL COVERED
RESTORATIONS
4)INABILITY TO LOCATE EXTRACANALS(MISSED CANAL
ORIFICES)
5)INABILITY TO NEGOTIATE BLOCKED CANALS.
6)IATROGENIC PERFORATIONS(CERVICAL
PERFORATIONS)
1)TREATING THE WRONG TOOTH:
ARRIVING AT DIAGNOSIS & DESIGNING A TREATMENT
PLAN BEFORE BEGINNING ANY PROCEDURES CAN
DEFINITELY BRING DOWN THE NO.OF PROCEDURAL
MISHAPS THAT CAN OCCUR.
PREVENTION: SUITABLE MARKING ON RADIOGRAPH &
ALSO TOOTH IN QUESTION IN ORAL CAVITY BEFORE THE
APPLICATION OF RUBBERDAM.

4. 2)INCOMPLETE REMOVAL OF CARIES:
 SECONDARY CARIES UNDER EXISTING
RESTORATION IS ONE OF RESON FOR ENDODONTIC
THERAPY IN CERTAIN CASES.
 IT IS RECOMMENDED THAT AN EXISTING OLD
RESTORATION ESPECIALLY INVOLVING
.OCCLUSOPROXIMAL AREAS SHOULD BE REMOVED
IN TOTAL AND ACCESS CAVITY DESIGNED
ACCORDINGLY .
 ALL CARIES MUST BE REMOVED FROM A TEETH
RECEVING CONTEMPARY ENDODONTIC
TREATMENT.
 OTHER COMMON ERRORS OCCURS IN DISTAL
CARIOUS LESIONS INVOLVING PULP.
 CLINICIAN SHOULD REMEMBER THAT SECONDARY
CARIES IN AN ENDODONTICALLY TREATED TEETH
ULTIMATLY LEADS TO CORONAL LEKAGE AND
ENDODONTIC FAILURE.
 COMPLETE REMOVAL OF CARIOUS PROCESS
SHOULD BE FIRST PRINCIPLE OF ACCESS OPENING
BEFORE FOCUSSING ON CANAL ORIFICE LOCATION.
3) ACCESS OPENING THROUGH THE FULL COVERAGE
RESTORATION

5.  WHEN PATIENTS COMPLAINS WITH CROWN IN
TOOTH THAT IS PLANED FOR ENDODONTIC
TREATMENT , BEST SOLUTION IS TO REMOVE THE
CROWN AND PROCEED WITH TREATMENT.
 IF A SOFT CARIOUS LESION IS SUSPECTED UNDER
CROWN FROM A RADIOGRAPH , ONE SHOULD TAKE
A CLINICAL DECISION TO REMOVE THE CROWN
EVEN AT COST OF THE REMAINING TOOTH
STRUCTURE.
 BURS ARE AVAILABLE FOR CUTTING THROUGH
THE CERAMIC CROWN WITH OUT CHIPPING OF
CROWN .
4) MIXED CANAL ORIFICES :
 CAUSES : FAILURE TO EXTERNALIZE THE INTERNAL
ANATOMY WHILE STUDYING THE PRE OPERATIVE
RADIOGRAPH .
 LACK OF KNOWLEDGE PERTAINING TO ROOT
CANAL ANATOMY CONFIGURATION AND ITS
VARIATIONS.
 IMPROPER ACCESS AND NOT OBSERVING BASIC
CAVITY DESIGN FEATURES .
 ACCESS OPENING IN BOTH MAXILLARY AND
MANDIBULAR MOLARS ARE ALWAYS ON MESIAL
HALF OF OCCLUSAL SURFACE RARELY EXTENDING
ACROSS THE MIDLINE

6.  IN MAXILLARY PREMOLARS,OPENING IS ALWAYS
BUCCOLINGUAL WITH ONE CANAL UNDER BUCCAL
CUSP AND ONE UNDER PALATAL CUSP
 INCOMPLETE DEROOFING OF PULP CHAMBER AND
REMOVAL AND SHAPING OF LATERAL WALLS OF
PULP CHAMBER
5) CLUES IN LOCATING EXTRACANALS:
 CASE REPORT OF MANDIBULAR 1ST MOLAR WITH A
MIDDLE MESIAL CANAL
 CASE REPORT OF MANDIBULAR 2ND PREMOLARS
WITH 4 CANALS
PREVENTION AND ACTION:
 GOOD IOPA PREOPERATIVELY AND DURING ROOT
CANAL CLEANING AND SHAPING UNDER
MAGNIFICATION
 MULTIPLE RADIOGRAPHS IN VARYING
ANGULATION MADE CLINICIANS TO UNDERSTAND
BETTER ABOUT MORPHOLOGY OF TOOTH,AIDS IN
TRACING EXTRACANALS.
 NON USE OF SURGICAL LOUPES AND DOMS,DG 16
EXPLORERS,ISO K-FILE INSTRUMENTS TO LOCATE
ORIFICES.
6) IATROGENIC CERVICAL PERFORATION:
 CERVICAL PERFORATION USUALLY OCCURS IN
FORM OF GOUGING WHICH LEADS TO CROWN
PERFORATION CAUSED BY DIRECTING THE BUR
NON PARALLEL TO LONG AXIS OF TOOTH.

7. MANAGEMENT OF NON FURCAL CERVICAL
PERFORATION:
 PRIMARY PROTCOL IS HEMORRAHAGE CONTROL
WITH 1:50,000 EPINEPHRINE FOLLOWED BY
PERFORATION REPAIR WITH MTA
PREVENTION:
 ONE MUST STUDY THE CROWN ROOT ANGULATION
OF MAXILLARY LATERAL INCISORS AND
MANDIBULAR 1ST PREMOLAR TEETH BEFORE
PROCEEDING WITH TRETMENT AS THESE TEETH
ARE THOSE WITH NORMALLY EXHIBIT
SIGNIFICANT CROWN ROOT ANGULATION.
 INA STEP FOR COMPLETE CARIES REMOVAL CARE
SHOULD BE TAKEN NOT TO REMOVE HEALTHY
DENTIN AND UNDERMINING THE CROWN TOOTH
STRUCTURE WHICH MIGHT RESULT IN
PERFORATION
MANAGEMENT OF CERVICAL PERFORATION IN FURCAL
AREA:
 ONCE THERE IS FLOODING OF BLOOD INTO THE PULP
CHAMBER, ONE MUST SUSPECT A PERFOARTION
LIKELY INTO PERIODONTAL TISSUES OR FURCATION.
 THIS MUST IMMEDIATELY CONFIRMED WITH
RADIOGRAPHS.

8.  AM ELECTRONIC APEX LOCATOR IS VERY USEFUL IN
DIFFERNTIATING A BLEEDING CANAL FROM
PERFORATION
 MTA IS MATERIAL OF CHOICE FOR SEALING
PERFORATIONS
 ACCESS BUR PERFORATIONS FOR DEPTH AND
ANGULATION SHOULD BE CONFIRMED BEFORE
PROCEEDING WITH DESINGING ACCESS CAVITY
 STRAIGHT LINE ACCESS IS CARDINAL RULE IN ALL
ACCESS PREPARATION
 WITH MAXILLARY LATERAL AND MANDIBULAR 1ST
PREMOLAR ALWAYS FOLLOW “STAY LINGUAL RULE”
 IN DEALING WITH CALCIFICATIONS IN CHAMBER THE
PULP SPACE,THE ENDODONTIST MUST EXTERNALIZE
THE INTERNAL ANATOMY OF THE PULP SPACE.
 DOM IS RECOMMENDED AS GREATER MAGNIFICATION
AND ILLUMINATION ENABLES A CLINICIAN TO
PREVENT AND MANAGE PROCEDURAL ERRORS
 GOUGING AND PERFORATIONS OF CROWN CUASED BY
DIRECTING THE BUR NON PARALLEL TO THE LONG
AXIS OF THE TOOTH AFTER INITIAL PREPARATION .
PROCEDURAL ERRORS IN CANAL CLEANING AND
SHAPING
INCLUDES:
 CANAL BLOCKAGE AND LEDGE FORMATION
 DEVIATION FROM NORMAL CANAL ANATOMY

9.  SEPERATION OF INSTRUMENTS
 OBSTRUCTION BY PREVIOUS OBTURATING
MATERIALS
CANAL BLOCKAGE AND LEDGE FORMATION
 CANAL BLOCKAGE IS DUE TO APICAL PUSHING OF
DENTINAL DEBRIS WHICH HAS BEEN REMOVED
DURING CLEANING AND SHAPING
PREVENTION
 ALWAYS USE SMALLER SIZED INSTRUMENTS FRIST
 USE INSTRUMENTS IN SEQUENTIAL ORDER
 ALWAYS PRECURVE STAINLESS STEEL HAND
INSTRUMENTS
 USE COPIOUS AMOUNT OF IRRIGANTS AND ALWAYS
WORK IN WET CANAL
 USE REPRODUCBLE REFERNCE POINTS AND STABLE
SILICON STOPPERS ON INSTRUMENTS WHILE
CLENAING AND SHAPING
LEDGE IS AN ARTIFICIALLY CREATED IRREGULARITY IN
THE SURFACE OF ROOT CANAL WALL THAT PREVENTS
THE PASSAGE OF AN INSTRUMENTS TO THE APEX
CAUSES:

10.  NOT EXTENDING THE ACCESS CAVITY
SUFFICIENTLY TO ALLOW ADEQUATE ACCESS TO
THE APICAL PART OF THE ROOT CANAL
 COMPLETE LOSS OF CONTROL OF INSTRUMENT IF
THE ENDODONTIC TREATMENT IS THROUGH A
PROXINMAL RESTORATION
 INCORRECT ACCESSMENT OF CANAL CURVATURE
 ERRONEOUS CANAL LENGTH DETERMINATION
 FORCING AND DRIVING THE INSTRUMENT
 USING A NON CURVED STAINLESS STEEL
INSTRUMENT
 FAILURE TO USE THE INSTRUMENTS IN
SEQUENTIAL ORDER
 ATTEMPTING TO RETRIVE BROKEN INSTRUMENTS
 REMOVING OF FILLING MATERIALS DURING RE-
TREATMENT
 ATTEMPTING TO PREPARE CALCIFIED CANALS
PREVENTION OF LEDGE:
 PRE-OPERATIVE RADIOGRAPH TO ASSES AND
ANTICIPATE UNUSUAL CANAL CURVATURE
 PATENCY OF CANAL SHOULD BE MAINTAINED
 RECAPTULATION WITH SMALLER INSTRUMENTS IN
BETWEEN EACH CHANGE OF INSTRUMENT IS
RECOMMENDED
 WORK PASSIVELY WITHOUT FORCING THE
INSTRUMENT

11.  WORK SEQUENTIALLY INCREASING THE SIZES OF
INSTRUMENTS
LEDGE MANAGEMENT:
 EARLY RECOGNITION OF HAVING CREATED A
LEDGE IS SIGNIFICANT
 LEDGE CREATED BY SMALLER INSTRUMENTS ARE
EASIER TO BY PASS AND MAKE THE PATHWAY TO
MAIN CANAL EASIER WHILE LARGER
INSTRUMENTS CREATE A TABLE
 PRE-CURVE OR OVER CURVE THE APICAL 3-4MM OF
FILE WITH A SAME CURVATURE AS SEEN IN
RADIOGRAPH AND TEASE THE FILE UNTILL IT IS
ABLE TO BYPASS THE LEDGE
 IF THE LEDGE CLOSER TO APICAL
TERMINUS,COMPLETE THE CANAL CLEANING AND
SHAPING AND OBTURATE WITH INJECTABLE
THERMOPLASTIC OBTURATION TECHNIQUE.
DEVIATION FROM NORMAL CANAL ANATOMY
 ZIPPING IS THE TRANSPORTATION OF APICAL
PORTION OF CANAL
CAUSES
EXISTING CURVED CANAL THAT HAS BEEN
STRAIGHTENED

12.  WHEN USING STAINLESS STEEL
INSTRUMENTS,BASIC CARDINAL RULE IS
1. ALWAYS PRECURVE THE INITIAL SMALL SIZED
HAND INSTRUMENT
2. DO NOT SKIP SIZES OF INSTRUMENTS
3. NEVER ROTATE THE INSTRUMENTS IN CURVED
CANALS
 WHEN A FILE IS ROTATED IN CURVED CANAL AT
THE APICAL AREA,A BIOMECHANICAL DEFECT
RESULTS IN FORM OF AN ELBOW.
 IT PRODUCES AN ELLIPTICAL PREPARATION WHICH
IS CONE SHAPED MAKING THE APICAL THIRD
DIFFICULT TO OBTURATE.
 THIS ELLIPTICAL PREPARTION HAS THE “ELBOW”
OR APEX TOWARDS THE MIDDLE THIRD OF THE
CANAL AND THE BASE OR “ZIP” TOWARDS THE
CEMENTUM SURFACE.
 IF THE INSTRUMENT
REMAINS IN CANAL-INTERNAL
TRANSPORTATION
OUTSIDE THE CANAL-EXTERNAL
TRANSPORTATION
MANAGEMENT
PREVENTION IS THE BEST FORM OF MANAGEMENT
IN CASES OF ZIP,ANY TYPE OF OBTURATION CAN BE
USED BUT THERMOPLASTICIZED ARE PREFERRED

13. INSTRUMENT SEPERATION IN THE CANAL:
 INSTRUMENTS SEPARATE OR BREAK ONLY WHEN
THEY ARE USED INCORRECTLY OR OVERUSED
 THE PROGNOSIS AND MANGEMENT DEPENDS UPON
1. LEVEL OF INSTRUMENT SEPERATION IN THE CANAL
2. SIZE OF INSTRUMENT
3. DEGREE OF INFECTION BEYOND THE LEVEL OF
SEPERATION
 PARASHOS AND MESSER RECOMMENDED THE
FOLLOWING GUIDE LINES TO MINIMIZE THE
INCIDENCE OF INSTRUMENT SEPERATION
1. CREATE A GLIDE PATH AND PATENCY WITH SMALL
HAND FILES
2. ENSURE STRAIGHT LINE ACCESS AND GOOD
FINGER REST
3. USE A CROWN-DOWN SHAPING TECHNIQUE
4. USE STIFFER LARGER AND STRONGER FILES
5. USE A LIGHT TOUCH ON THE INSTRUMENTS
6. AVOID JERKING AND HURRING OF INSTRUMENTS
7. AVOID KEEPING THE FILE IN ONE
SPOT,PARTICULARLU IN CURVED CANALS
8. THE CANAL SHPOUL BE FLOODED WITH SODIUM
HYPOCHOLRITE AS THE INSTRUMENST IS PASSED
THROUGH THE CANAL

14. ObSTRUCTION FROM PREVIOUS OBTURATING
MATERIALS
 WHEN RETREATMENT OF A PREVIOUSLY TREATED
TOOTH BECOMES NECESSARY THE FILLING
MATERIAL MUST BE REMOVED OR BYPASSED
 BECAUSE MOST TEETH TO BE RETREATED ARE
SEALED WITH GUTTA PERCHA AND IN SOME CASES
SILVER CONES.THE FOLLOWING IS DISCUSSED TO
REMOVE AS A MATERIAL.
GUTTA PERCHA-CAN BE REMOVED BY
APPLICATION OF
 MECHANICAL FORCE IN THE FORM OF
INSTRUMENTATION
 HEAT TO SEAR AND SOFTEN
 SOLVENTS(CHLOROFORM,XYLOL,HALOTHANE,EUC
ALYPTUS OIL)
 ULTRASONICS
 COMBINATIONS OF ABOVE
 20 OR 25 H-FILE THROUGH THE ORIFICE OR GATES –
GLIDEN DRILL CAN BE USED
SILVER CONE-
IT IS NOT EASILY REMOVED AS GUTTA PERCHA
CONE UNLESS THE BUTT END OF SILVER CONE EXTENDS
INTO PULP CHAMBER

15.  IN SUCH CASES BUTT END OF SILVER CONE IS
VIBRATED WITH AN ULTRASONIC SCALER TO
BREAK THE CEMENTING MEDIA.
• THE CONE IS THEN GRASPED WITH A PAIR OF
NARROW
BEAKED(STIEGLITZ)PLIERS AND IS REMOVED
PROCEDURAL ERRORS IN OBTURATION:
UNDER FILLING OF GUTTA PERCHA:
 THIS HAPPENS MAINLY DUE TO LOSS OF WORKING
LENGTH AS A RESULT OF PACKING DENTINAL MUD
INTO PULP SPACE WITHOUT RECAPTUALTION OR
INSUFFICIENT IRRIGATION
 THE USE OF SMALL SIZE FILES TO DISLODGE THE
PACKED DENTINAL MUD AND IRRIGATION
WITHSODIUM HYPOCHLORITE IS FREQUENTLY
RECOMMENDED
OVER FILLING OF GUTTA PERCHA:
INSTRUMENTING BEYOND CONSTRICTION DURING ROOT
CANAL THERAPY SHOULD NOT ROUTINELY HAPPEN IF
BASIC BIOLOGICAL AND MECHANICAL PRINCIPLES ARE
OBSERVED AS CARDINAL RULES
OTHER PROCEDURAL ERRORS
ASPIRATIONAL OR INGESTION OF ENDODONTIC
INSTRUMENTS

16. -IT HAPPENS ONLY WHEN RUBBER DAM IS NOT IN PLACE
-IT CAN BE CLOINICAL DIASTER ENDING UP IN A LIFE
THREATENING SITUATIONS OR ENDING UP IN THE NEED
FOR MAJOR SURGERY TO REMOVE THE INSTRUMENT
IRRIGATION RELATED MISHAPS
-THE STANDARD REGIMEN OF IRRIGATION ROUTINELY IS
0.1-5.2% NaOCl WITH 17%EDTA WHICH IS PASSIVE IN
NATURE IN ENDO.
-SIGNS OF HYPOCHLORITE ACCIDENT
SEVERE AND EXCRUTIATING PAIN EVEN IN AREAS THAT
WERE PREVIOUSLY ANASTHETIZED FOR DENTAL
TREATMENT
SUDDEN FLOODIN OF CANAL WITH BLOOD AND TISSUE
FLUIDS
THERE MAY BE BALLONING OF TISSUES AND SWELLING
OF SOFT TISSUES.
MANAGEMENT
 INFORM AND COMMUNICATE WITH PATIENT THAT
THE INEVITABLE HAS HAPPENED
 IF NOT UNDER LOCAL ANESTHETIC,GIVE BLOCK
ANESTHESIA
 ALLOW THE BLEEDING FROM THE CANAL TO
CONTINOUSLY FLOW SINCE THIS IS A
PHYSIOLOGICAL DEFENCE MECHANISM

17.  FLOOD THE CANAL WITH NORMAL SALINE SO THAT
THE MUCH OF BLOOD ACCUMULATED WILL COME
OUT AND DECREASE THE PAIN
PREVENTION
 ALWAYS USE PASSIVE IRRIGATION AND NEVER
PUMP THE IRRIGANT INTO THE PULP SPACE
 IN OPEN APICES,NEVER FORCE IRRIGANT AT THE
APICAL FEW MM
 TO AVOID FLUSHING THE CANAL, KEEP THE
NEEDLE PASSIVELY FITTING IN THE CANAL AND
DONOT WEDGE IT AGAINST APICAL THIRD
AREA.THERE ARE SEVERAL DISPENSING NEEDLES
AVAIBLE WITH LATERAL OPENING AND THE MAIN
LUMEN OPENING 1MM FROM THE TIP WITH APICAL
END CLOSED.
COMPOSITES CLASSIFICATION
 BASED ON THE MEAN PARTICLE SIZE OF THE
MAJOR FILLER
1. TRADITIONAL COMPOSITES --- 8-12 um
2. SMALL PARTICAL COMPOSITES – 1 – 5um
3. MICROFILLED COMPOSITES ---- -0.04 – 0.4 um

18. 4. HYBRID COMPOSITES ------- 0.6 – 1 um
 BASED ON FILLER PARTICLE SIZE AND
DISTRIBUTION:-
1. MACROFILLERS ---- 10 TO 100 um
2. MIDIFILLERS ----- 1 TO 10 um
3. MINIFILLERS ----- 0.1 TO 1 um
4. MICROFILLERS ----- 0.01 TO 0.1 um
5. NANOFILLERS ----- 0.005 TO 0.01 um
 BASED ON METHOD OF POLYMERIZATION
1. SELF CURED , AUTO CURED , OR CHEMICALLY
CURED COMPOSITES
2. LIGHT CURED COMPOSITES
I. UV LIGHT CURED
II. VISIBLE LIGHT CURED
3. DUAL CURED COMPOSIES – BOTH LIGHT&SELF
CURING MECHANISMS
4. STAGED CURING COMPOSITES – INITIAL SOFT START
POLYMERIZATION FOLLOWED BY COMPLETE
 BASED ON MODE OF PRESENTATION
1. TWO PASTE SYSTEM
2. SINGLE PASTE SYSTEM
3. POWDER LIQUID SYSTEM

19. BASED ON USE
1. ANTERIOR COMPOSITES
2. CORE BUILD UP COMPOSITES
3. POSTERIOR COMPOSITES
4. LUTING COMPOSITES
 BASED ON THEIR CONSISTENCY
1. LIGHT BODY COMPOSITES – FLOWABLE
COMPOSITES
2. MEDIUM BODY COMPOSITES – MEDIUM VISCOSITY
COMPOSITES LIKE MICRO FILLED , HYBRID , MICRO
HYBRID COMPOSITES
3. HEAVY BODY COMPOSITES – PACKABLE
COMPOSITES
COMPOSITE CHEMISTRY

20.  Dental composite is composed of a resin matrix and filler
materials.
 Coupling agents are used to improve adherence of resin to
filler surfaces.
 Activation systems including heat, chemical and
photochemical initiate polymerization.
 Plasticizers are solvents that contain catalysts for mixture into
resin.
 Monomer, a single molecule, is joined together to form a
polymer, a long chain of monomers.
 Physical characteristics improve by combining more than one
type of monomer and are referred to as a copolymer.
 Cross linking monomers join long chain polymers together
along the chain and improve strength.

21. COMPOSITION OF COMPOSITE RESINS
 RESIN MATERIALS
 FILLERS
 COUPLING AGENTS
 ACTIVATOR – INITIATOR SYSTEM
 INHIBITORS
 OPITICAL MODIFIERS/ COLOURING AGENTS
RESIN MATERIALS
 BIS-GMA resin is the base for composite.
 In the late 1950's, Bowen mixed bisphenol A and
glycidylmethacrylate thinned with TEGDMA (triethylene
glycol dimethacrylate) to form the first BIS-GMA resin.
 Diluents are added to increase flow and handling
characteristics or provide cross linking for improved
strength.
 Common examples are:
 RESIN:- BIS-GMA bisphenol glycidylmethacrylate
 DILUENTS:- MMA methylmethacrylate
BIS-DMA bisphenol dimethacrylate
UDMA urethane dimethacrylate
 CROSS LINK DILUENTS

22. TEGDMA triethylene glycol dimethacrylate
EGDMA ethylene glycol dimethacrylate
COMPOSITE FILLERS
 Fillers are placed in dental composites to reduce shrinkage
upon curing.
 Physical properties of composite are improved by fillers,
however, composite characteristics change based on filler
material, surface, size, load, shape, surface modifiers, optical
index, filler load and size distribution.
 Materials such as strontium glass, barium glass, quartz,
borosilicate glass, ceramic, silica, prepolymerized resin, or
the like are used.
COUPLING AGENTS
 Coupling agents are used to improve adherence
of resin to filler surfaces.
 Coupling agents chemically coat filler surfaces and increase
strength.
 Silanes have been used to coat fillers for over fifty years in
industrial plastics and later in dental fillers. Today, they are
still state of the art.
 Silanes have disadvantages. They age quickly in a bottle and
become ineffective. Silanes are sensitive to water so the
silane filler bond breaks down with moisture.
 Water absorbed into composites results in hydrolysis of the
silane bond and eventual filler loss.
 Common silane agents are:

23. vinyl triethoxysilane
methacryloxypropyltrimethoxysilane
ACTIVATOR – INITIATOR SYSTEM
TYPE OF COMPOSITE ACTIVATOR INITIATOR
CHEMICALLY CURED N .N .DI METHYL P- TOLUIDINE BENZOYLPEROXIDE
LIGHT CURED
1. UV LIGHT TERTIARY AMINE BENZOIN METHYL ETHER
2 VISIBLE LIGHT DIMETHYL AMINO ETHYL CAMPHOROQUINONE
METHACRYLATE
INHIBITORS
 ADDED TO PREVENT SPONTANEOUS
POLYMERIZATION OF THE MONOMERS BY
INHIBITING THE FREE RADICALS
 BUTYLATED HYDROXY TOLUENE 0.01 % IS ADDED
AS INHIBITOR IN COMPOSITE RESINS
OPTICAL MODIFIERS / COLOURING AGENTS
 METAL OXIDES – MINUTE AMOUNT – PRODUCE
DIFFERENT
SHADES TO
COMPOSITES

24.  ALUMINIUM OXIDE & TITANIUM OXIDE – OPACITY
TO COMPOSITES
 ALL OPTICAL MODIFIERS AFFECT LIGHT
TRANSMISSION THROUGH THE COMPOSITES
RESINS. SO DARKER SHADES AND GREATER
OPACITES HAVE A LESSER DEPTH OF CURING THAN
LIGHTER SHADES
Physical Characteristics
 Following are the imp physical properties:-
 1) Linear coefficient of thermal expansion (LCTE)
 2) Water Absorption
 3) Wear resistance
 4) Surface texture
 5) Radiopacity
 6) Modulus of elasticity
 7) Solubility
Radiospacity
 One of the requirements of using a composite as a posterior
restorative is that it should be radiopaque.

25.  In order for a material to be described as being radiopaque,
the International Standard Organization (ISO) specifies that it
should have radiopacity equivalent to 1 mm of aluminium,
which is approximately equal to natural tooth dentine.
 However, there has been a move to increase the radiopacity to
be equivalent to 2 mm of aluminium, which is approximately
equal to natural tooth enamel.
 A majority of the composites described as all-purpose or
universal have levels of radiopacity greater than 2 mm of
aluminium

26. INDICATIONS
 1) Class-I, II, III, IV, V & VI restorations.
 2) Foundations or core buildups.
 3) Sealant & Preventive resin restorations.
 4) Esthetic enhancement procedures.
 5) Luting
 6) Temporary restorations
 7) Periodontal splinting.
CONTRAINDICATIONS
 1) Inability to isolate the site.
 2) Excessive masticatory forces.
 3) Restorations extending to the root surfaces.
 4) Other operator errors.
 5) high caries incidence and poor oral hygiene
ADVANTAGES
 1) Esthetics
 2) Conservative tooth preparation.
 3) Insulative.
 4) Bonded to the tooth structure.
 5) repairable.
 6) command set
 7) can be polished

27.  8) low thermal conductivity
DISADVANTAGES
 1) May result in gap formation when restoration extends to
the root surface.
 2) Technique sensitive.
 3) Expensive
 4) May exhibit more occlusal wear in areas of higher
stresses.
 5) Higher linear coefficient of thermal expansion.
STEPS IN COMPOSITE RESTORATION
 1) Local anaesthesia.
 2) Preparation of the operating site.
 3) Shade selection
 4) Isolation of the operating site.
 5) Tooth preparation.

28.  6) preliminary steps of enamel and dentin bonding.
 7) Matrix placement.
 8) Inserting the composite.
 9) Contouring the composite.
 10) polishing the composite.
PRINCIPLES OF ANTERIOR COMPOSITE RESTORATION
 1. Smile Design
 2. Color and Color Analysis
 3. Tooth Color
 4. Tooth Shape
 5. Tooth Position
 6. Esthetic Goals
 7. Composite Selection
 8. Tooth Preparation
 9. Bonding Techniques
 10. Composite Placement
 11. Composite Sculpture and
 12. Composite Polishing to properly restore anterior teeth
with composite:
SMILE DESIGN
 A dentist must understand proper smile design so composite restoration
can achieve a beautiful smile. This is true for extensive veneering and
small restorations.
 Factors which are considered in smile design include:-

29. A. Smile Form which includes size in relation to the face, size of one
tooth to another, gingival contours to the upper lip line, incisal edges
overall to the lower lip line, arch position, teeth shape and size,
perspective, and midline.
B. Teeth Form which includes understanding long axis, incisal edge,
surface contours, line angles, contact areas, embrasure form, height of
contour, surface texture, characterization, and tissue contours within an
overall smile design.
C. Tooth Color of gingival, middle, incisal, and interproximal areas and the
intricacies of characterization within an overall smile design.
COLOUR AND COLOUR ANALYSIS
 Colour is a study in and of itself. In dentistry, the effect of
enamel rods, surface contours, surface textures, dentinal light
absorption, etc. on light transmission and reflection is
difficult to understand and even more difficult replicate.
 The intricacies of understanding matching and replicating
hue, chroma, value, translucency, florescence; light
transmission, reflection and refraction to that of a natural
tooth under various light sources is essential but far beyond
the scope of this article.
4. TOOTH COLOUR
 Understanding tooth shape requires studying dental anatomy.
 Studying anatomy of teeth requires recognition of general
form, detail anatomy and internal anatomy.
 It is important to know ideal anatomy and anatomy as a result
of aging, disease, trauma and wear.

30.  Knowledge of anatomy allows a dentist to reproduce natural
teeth. For example, a craze line is not a straight line as often
is produced by a dentist, but is a more irregular form guided
by enamel rods.
5. 4. TOOTH SHAPE
 Understanding tooth shape requires studying dental anatomy.
 Studying anatomy of teeth requires recognition of general
form, detail anatomy and internal anatomy.
 It is important to know ideal anatomy and anatomy as a result
of aging, disease, trauma and wear.
 Knowledge of anatomy allows a dentist to reproduce natural
teeth. For example, a craze line is not a straight line as often
is produced by a dentist, but is a more irregular form guided
by enamel rods.

31. 5. TOOTH POSITION
 Knowledge of normal position and axial tilt of teeth within a
head, lips, and arches allows reproduction of natural beautiful
smiles.
 Understanding the goals of an ideal smile and compromises
from limitations of treatment allows realistic expectations of
a dentist and patient.
 Often, learning about tooth position is easily done through
denture esthetics.
 Ideal and normal variations of tooth position is emphasized in
removable prosthetics so a denture look does not occur.
6. ESTHETIC GOALS
 The results of esthetic dentistry are limited by limitations of
ideals and limitations of treatment.
 Ideals of the golden proportion have been replaced by
preconceived perceptions.
 Limitations of ideals are based on physical, environmental
and psychological factors.
 Limitations of treatment are base on physical, financial and
psychological factors.

32. 6. COMPOSITE SELECTION
 Esthetic dentistry is an art form. There are different levels of
appreciation so individual dentists evaluate results of esthetic
dentistry differently. Artistically dentists select composites
based on their level of appreciation, artistic ability and
knowledge of specific materials. Factors which influence
composite selection include
 A- Restoration Strength,
 B- Wear
 C- Restoration Color
 D- Placement characteristics.
 E- Ability to use and combine opaquers and tints.
 F- Ease of shaping.
 G- Polishing characteristics.
 H- Polish and colour stability
8. TOOTH PREPARATION
 Tooth preparation often defines restoration strength.
 Small tooth defects which receive minimal force require
minimal tooth preparation because only bond strength is
required to provide retention and resistance.

33.  In larger tooth defects where maximum forces are applied,
mechanical retention and resistance with increased bond area
can be required to provide adequate strength.
9. BONDING TECHNIQUES
 Understanding techniques to bond composite to dentin and
enamel provide strength, elimination of sensitivity and
prevention of micro-leakage.
 Enamel bonding is a well understood science. Dentinal
bonding, however, is constantly changing as more research is
being done and requires constant periodic review.
 Micro-etching combined with composite bonding techniques
to old composite, porcelain, and metal must be understood to
do anterior composite repairs.
10. COMPOSITE PLACEMENT TECHNIQUE
 Understanding techniques which allow ease of placement,
minimize effects of shrinkage, eliminate air entrapment and
prevent material from pulling back from tooth structure
during instrumentation determine ultimate success or failure
of a restoration.

34.  It is important to incorporate proper instrumentation to allow
ease of shaping tooth anatomy and provide color variation
prior to curing composite.
 In addition, a dentist must understand placement of various
composite layers with varying opacities and color to replicate
normal tooth structure.
11. COMPOSITE SCULPTURE
 Composite sculpture of cured composite is properly done if
appropriate use of polishing strips, burs, cups, wheels and
points is understood.
 In addition, proper use of instrumentation maximizes
esthetics and allows minimal heat or vibrational trauma to
composite resulting in a long lasting restoration.
12. COMPOSITE POLISHING
 Polishing composite to allow a smooth or textured surface
shiny produces realistic, natural restorations.

35.  Proper use of polishing strips, burs, cups, wheels and points
with water or polish pastes as required minimizes heat
generation and vibration trauma to composite material for a
long lasting restoration.
DIRECT POSTERIOR COMPOSITES
 Composites are indicated for Class 1, class 2 and class 5
defects on premolars and molars. Ideally, an isthmus width
of less than one third the intercuspal distance is required.
 This requirement is balanced against forces created on
remaining tooth structure and composite material.
 Forces are analyzed by direction, frequency, duration and
intensity.
 High force occurs with low angle cases, in molar areas, with
strong muscles, point contacts and parafunctional forces such
as grinding and biting finger nails.
 Composite is strongest in compressive strength and weakest
in shear, tensile and modulus of elasticity strengths.
 Controlling forces by preparation design and occlusal
contacts can be critical to restorative success.

36.  Failure of a restoration occurs if composite fractures, tooth
fractures, composite debonds from tooth structure or micro-
leakage and subsequent caries occurs.
 A common area of failure is direct point contact by sharp
opposing cusps.
 Enameloplasty that creates a three point contact in fossa or
flat contacts is often indicated.
 Tooth preparation requires adequate access to remove caries,
removal of caries, elimination of weak tooth structure that
could fracture, beveling of enamel to maximize enamel bond
strength, and extension into defective areas such as stained
grooves and decalcified areas.
 Matrix systems are placed to contain materials within the
tooth and form proper interproximal contours and contacts.
 Selection of a matrix system should vary depending on the
situation (see web pages contacts and contours in this
section).
 Enamel and dentin bonding is completed. Composite shrinks
when cured so large areas must be layered to minimize
negative forces.
 Generally, any area thicker than two millimeters requires
layering. In addition, cavity preparation produces multiple
wall defects.
 Composite curing when touching multiple walls creates
dramatic stress and should be avoided.
 Composite built in layers replicate tooth structure by placing
dentin layers first and then enamel layers.

37.  Final contouring with hand instruments is ideal to minimize
the trauma of shaping with burs.
 Matrix systems are removed and refined shaping and occlusal
adjustment done with a 245 bur and a flame shaped finishing
bur. Interproximal buccal and lingual areas are trimmed of
excess with a flame shaped finishing bur.
 Final polish is achieved with polishing cups, points,
sandpaper disks, and polishing paste.
INDIRECT POSTERIOR COMPOSITES
 Indirect laboratory composite is indicated on teeth that
required large restorations but have a significant amount of
tooth remaining.
 It is used when a tooth defect is larger than indicated for
direct composite and smaller than indicated for a crown.
 A common situation is fracture of a single cusp on a molar
or a thin cusp on a bicuspid.

38.  Force analysis is critical to success as high force will fracture
composite, tooth structure or separate bonded interfaces.
 High force is indicated on teeth furthest back in the mouth
for example, a second molar receives five times more force
than a bicuspid.
 Orthodontic low angle cases and large masseter muscles
generate high force.
 Sharp point contacts from opposing teeth create immense
force and are often altered with enameloplasty.
 Indirect composite restorations are processed in a laboratory
under heat, pressure and nitrogen to produce a more thorough
composite cure.
 Pressure and heat increase cure while nitrogen eliminates
oxygen that inhibits cure.
 Increased cure results in stronger restorations.
 Strength of laboratory processed composite is between
composite and crown strength and requires adequate tooth
support.
TOOTH PREPARATION
 Tooth preparation requires removal of existing restorations
and caries. Thin cusps and enamel are removed in

39. combination of blocking out undercuts with composite, glass
ionomer, flowable composite or the like.
 Tooth preparation requires adequate wall divergence to bond
and cement the restoration and ideally, margins should finish
in enamel. The restoration floor is bonded and light cured.
 Bonding agent is light cured to stabilize collagen fibers and
avoid collapse during restoration placement. A base of glass
ionomer or composite is used if thermal sensitivity is
anticipated.
 Restoration retention is judged by bonded surface area,
number and location of retentive walls, divergence of
retentive walls, height to width ratio and restoration internal
and external shape.
 Resistance form, reduction of internal stress and conversion
of potential shear and tensile forces is accomplished by
smoothing sharp areas and creating flat floors as opposed to
external angular walls.
Impressions are taken of prepared teeth, models poured and
composite restorations constructed at a laboratory. Temporaries are
placed and a second appointment made.
 At a second appointment, temporaries are removed and a
rubber dam placed. Restorations are tried on the teeth and
adjusted. Manufacturers directions are followed. In general,
bonding is completed on the tooth surfaces and bonding resin
precured.

40.  Matrix bands are placed prior to etching to contain etch
within prepared areas. Trimming of excess cement where no
etching has occurred is easier.
 Composite surfaces are silinated and dual cure resin cement
applied. Restorations are seated, excess resin cement is
wiped away with a brush and then facial and lingual surfaces
are light cured. Interproximal areas are flossed and then light
cured. Excess is trimmed with hand instruments and
finishing flame shaped burs.
 The rubber dam is removed and occlusion adjusted. Surfaces
are finished and polished.
COMPOSITE WEAR
 There are several mechanisms of composite wear including
adhesive wear, abrasive wear, fatigue, and chemical wear.
 Adhesive wear is created by extremely small contacts and
therefore extremely high forces, of two opposing surfaces.
When small forces release, material is removed. All surfaces
have microscopic roughness which is where extremely small
contacts occur between opposing surfaces.
 Abrasive wear is when a rough material gouges out material
on an opposing surface. A harder surface gouges a softer
surface. Materials are not uniform so hard materials in a soft
matrix, such as filler in resin, gouge resin and opposing
surfaces. Fatigue causes wear. Constant repeated force
causes substructure deterioration and eventual loss of surface

41. material. Chemical wear occurs when environmental
materials such s saliva, acids or like affect a surface.