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Bonding to Enamel and Dentin (ramkumaradhikari)
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PRESENTED BY:
RAM KUMAR ADHIKARI
BDS FINAL YEAR
KU REGD. NO: A011320-09
KANTIPUR DENTAL COLLEGE TEACHING HOSPITAL AND RESEARCH CENTRE
CONTENTS
• KEY TERMS
• DEFINITION
• IDEAL REQUIREMENTS
• PROBLEMS IN BONDING OF DENTIN
• CHRONOLOGY OF DEVOLPMENT
• BONDING TO DENTIN
• ROLE OF SMEAR LAYER IN DENTIN BONNDING
• CONDITIONING OF DENTIN
• DENTIN BONDING AGENTS AND GENERATIONS
• COMPONENTS OF BONDING AGENTS
• INDICATIONS FOR CLINICAL EXAMINATION
• CRITICAL STEPS IN BONDING
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KEY TERMS
Dentin Bonding:
• The process of bonding a resin to conditioned dentin.
Dentin Bonding Agent:
• A thin layer of resin between conditioned dentin and the resin matrix of composite
Dentin Conditioner:
• An acidic agent that dissolves the inorganic structure in dentin, resulting in a collagen mesh that allows
infiltration of an adhesives.
Hybrid Layer:
• An intermediate layer of resin, collagen, and dentin produced by acid etching of dentin and resin
infiltration into the conditioned dentin.
Resin Tag:
• Extension of resin that has penetrated into etched enamel or dentin.
Smear Layer:
• Poorly adherent layer of ground dentin produced by cutting a dentin surface.
INTRODUCTION
• The first meaningful proof of intraoral
adhesion was reported in 1995 by
Michael Buonocore.
• He etched the enamel surface with acids
and then placed an acrylic restorative
material on the micromechanically
roughened surface. The monomers of the
acrylic resin wet the etched surface,
flowed into the etch pits, and generated
retentive tags.
• One of the surface conditioning agents he
used, phosphoric acid, is still the most
widely used etchant today for bonding to
enamel and dentin.
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Buonocore etched enamel with 85% phosphoric acid for 2 minutes and reported the acid:
1. cleaned the surface,
2. increased the surface area, and
3. possibly made sites available for bonding through the creation of a more
reactive surface.
Electron micrographs. A, Unetched enamel. Note that the enamel rod ends are about 0.5 μm in diameter and that they
are arranged in 3- to 6-μm clusters. B, Etched enamel. Note that the rods have been dissolved out of their 3- to 6-μm
clusters and that the organic matrix remains.
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Adherend 1 Adherend 2
Adhesive System
or Luting Cement
Interface 2Interface 1
AdhesiveInterface 1
DENTAL ADHESION
Diagrammatic representation of dental adhesive system, where Adherend 1
is enamel, dentin or both.
Adhesive is bonding agent,
Adherend 2 is composite resin
ENAMEL BONDING
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ENAMEL BONDING
Enamel
• the hardest tissue in the human body
• consists of 95 percent mineralized inorganic substance
• hydroxyapatite arranged in a dense crystalline structure and a small amount of protein
and water
ENAMEL BONDING
• To bond to enamel, it is very important to focus on the mineral component (hydroxyapatite) of
enamel.
• Buonocore, 1955
• was the first to reveal the adhesion of acrylic resin to acid etched enamel.
• used 85 percent phosphoric acid for etching
• Silverstone revealed that the optimum concentration of phosphoric acid should range between
30 to 40 percent to get a satisfactory adhesion to the enamel.
• IF
the concentration is greater than 50 percent
monocalcium phosphate monohydrate may get precipitated on etched surface
concentrations lower than 30 percent,
dicalcium phosphate monohydrate is precipitated which interferes with adhesion.
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ENAMEL BONDING (CONTD.)
• Percentage of etchants used:
• 37 %
• Use of lower concentrations of phosphoric acid
and reduced etching time has shown to give an
adequate etch of the enamel while avoiding
excessive demineralization of the dentin
• Acid application time: ideally 10 seconds
• studies show that enamel should not be
etched for more than 15 to 20 seconds
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STEPS FOR ENAMEL BONDING
• Clean and wash the teeth with water. Isolate to prevent any
contamination from saliva or gingival crevicular fluid
• Apply acid etchant in the form of liquid or gel for10 to 15
seconds. Deciduous teeth require longer time for etching
than permanent teeth because of the presence of aprismatic
enamel in deciduous teeth
• Wash the etchant continuously for 10 to 15 seconds
• Note the appearance of a properly etched surface. It should
give a frosty white appearance on drying
• If any sort of contamination occurs, repeat the procedure
• Now apply bonding agent and low viscosity monomers over the
etched enamel surface.
• Generally, enamel bonding agents contain Bis-GMA or UDMA with
TEGDMA added to lower the viscosity of the bonding agent.
• The bonding agents due to their low viscosity, rapidly wet and
penetrate the clean, dried, conditioned enamel into the
microspaces forming resin tags.
• The resin tags which form between enamel prisms are known as
Macrotags.
STEPS FOR ENAMEL BONDING
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The finer network of numerous small tags are formed across the end of each
rod where individual hydroxyapatite crystals were dissolved and are known as
microtags.
These microtags are more important due to their larger number and greater
surface area of contact. The formation of resin micro and macro tags within
the enamel surface constitute the fundamental mechanism of enamel-resin
adhesion.
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DENTIN BONDING
• Bonding to dentin has been proven more difficult and less reliable and predictable than
to enamel.
• This is basically because of difference in morphologic, histologic and compositional
differences between enamel and dentin.
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ENAMEL VS DENTIN
In enamel, it is 95 percent inorganic hydroxyapatite by volume, in dentin it is 50 percent.
Dentin contains more water than does enamel.
• Hydroxyapatite crystals
– have a regular pattern in enamel whereas in dentin, hydroxyapatite
crystals are randomly arranged in an organic matrix
• The presence of the smear layer
– makes wetting of the dentin by the adhesive more difficult
• Dynamic structure of dentin
– shows changes due to aging, caries or operative procedures.
ENAMEL VS DENTIN
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• Fluid present in dentinal tubules
constantly flows outwards
which reduces the adhesion of
the composite resin.
• Dentin contains dentinal tubules
which contain vital processes of
the pulp, odontoblasts.
– This makes the dentin a sensitive
structure
ENAMEL VS DENTIN
CONDITIONING OF DENTIN
• For removal or modification of the smear layer, many acids or/and
calcium chelators are used
• Commonly used 37 percent phosphoric acid
• Not only removes the smear layer but also exposes the microporous
collagen network into which resin monomer penetrates
• Usually, it forms exposed collagen fibrils which are covered with an
amorphous layer, a combination of denatured collagen fibers and the
collapsed residual collagen layer.
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CONDITIONING OF DENTIN
• For removal or modification of the smear layer, many acids
or/and calcium chelators are used.
• Commonly used 37 percent phosphoric acid.
• Not only removes the smear layer but also exposes the
microporous collagen network into which resin monomer
penetrates.
• Usually, it forms exposed collagen fibrils which are covered with
an amorphous layer, a combination of denatured collagen fibers
and the collapsed residual collagen layer.
Electron micrographs. A, The dentin surface prior to conditioning, and B, the dentin surface after conditioning.
The demineralized surface has voids that a primer can penetrate.
A B
A B
A, Scanning electron micrograph of etched dentin showing exposed collagen fibers. B, Higher magnification
shows the characteristic collagen banding in intertubular collagen. Superficial collagen was dissolved by
collagenase to remove the most superficial collagen fibers that were damaged by tooth preparation.
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PRIMING OF DENTIN
• Primers are agents which contain monomers having a hydrophilic
end with affinity for exposed collagen fibrils and a hydrophobic
end with affinity for adhesive resin
• Commonly used primers have HEMA and 4-META monomers,
dissolved in organic solvents.
• Primers are used to increase the diffusion of resin into moist and
demineralized dentin and thus optimal micromechanical bonding.
PRIMING OF DENTIN
• For optimal penetration of primer into demineralized dentin, it
should be applied in multiple coats.
• It is preferred to keep the dentin surface moist, otherwise collagen
fibers get collapsed in dry condition resisting the entry for primer
and adhesive resin.
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MOIST VS DRY DENTIN
• By etching dentin, the smear layer and minerals from it are removed,
exposing the collagen fibers.
• Areas from where minerals are removed are filled with water. This
water acts as a plasticizer for collagen, keeping it in an expanded soft
state.
• Thus, spaces for resin infiltration are also preserved. But these collagen
fibers collapse when dry and if the organic matrix is denatured.
• This obstructs the resin from reaching the dentin surface and forming a
hybrid layer.
• The desired effect of acid etching, which is increased permeability.
• For this reason, presence of moist/wet dentin is needed to achieve
successful dentin bonding.
• When primer is applied to wet/moist dentin, water diffuses from the
primer to the organic solvent and the solvent diffuses along with the
polymers into the demineralized dentinal matrix and tubules.
MOIST VS DRY DENTIN
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WET BONDING
• Primers consisting of hydrophilic resin monomers dissolved in water miscible
organic solvents like ethanol and acetone are used.
• Acetone-based primers are dependent on a moist dentin surface for
hybridization because the acetone displaces water present in the inter-fibrillar
spaces of the collagen network and carry hydrophilic resin along with it for
hybridization
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DRY BONDING
• Water-based primers are used.
• Water-based primers are not dependent on moist dentin because of their
ability to self-wet a dried dentin surface and thus separating the collapsed
collagen fibers.
• Studies show that moist dentin is friendly with all primer types, it is advisable
to have moist dentin for resin-dentin bonding.
• To get moist dentin after etching, do not dry the dentin with compressed air
after rinsing away etchant.
• Instead use high-volume evacuation to remove excess water and then blot the
remaining water present on the dentin surface using gauze or cotton to leave
dentin optimally moist.
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Bonding agents can be defined as material of low viscosity, when
applied on the tooth surface and forms thin film after setting.
This thin film strongly bonded to tooth surface, on which the
viscous composite restorative resin is applied. This sets forming an
integrated resin restoration
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Biocompatible
Non toxic, Non irritant, Non poisonous
Low film thickness, Low viscosity
Form strong permanent bond
Good dimensional stability
Low thermal conductivity
Good shelf life
Prevent micro leakage
ETCHING: dissolution of substrate, removed by rinsing to enhance
intimate contact of adhesive.
PRIMING: cleaning, structural alteration and increasing
adhesiveness of the substrate.
ADHESIVES: monomer (or related) that penetrates and
establishes intimate contact with conditioned tissue substrate,
polymerizes, and forms a strong bond between a such substrate
and restorative material.
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ADHESIVE RESINS
Hydrophobic monomers
BIS-GMA
UDMA
Diluent
TEGDMA
Wetting agent
HEMA
Dentin is a dynamic tissue that shows changes due to ageing, caries or
restorative procedures.
Dentinal tubules are filled with dentinal fluid which constantly flow
outward from the pulp.
Dentin has a considerable amount of organic material and water.
Dentin is close to pulp, so different chemical used for bonding and
etching may irritate the pulp.
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The molecule designed for dentin bonding were represented by an
M-R-X molecule.
M- methacrylate group for bonding to resin matrix of composite
resin
R- spacer such as hydrocarbon chain
X-functional group for bonding to organic or inorganic component
of dentin.
ROLES OF SMEAR LAYER
• Whenever tooth surface is cut with hand or rotary instruments , it causes small
particles of the cut tooth surface to the tooth producing the smear layer.
• Smear layer is defined as any debris ,calcific in nature ,produced by reduction or
instrumentation of enamel, of dentin or cementum.
• It has two phases
• Solid phase-made up of cutting debris , primarily denatured collagen and mineral.
• Liquid phase- made up of tortuous fluid filled channels around the cutting debris.
• Bacteria entrapped in smear layer can survive and multiply beneath the restoration.
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Retention of smear layer:-
1)lowers dentin permeability
2)prevent decrease in bond strength
3)lowers effect of pulpal pressure on
bond strength
Recent generations adhesives involves
modification of smear layer to
facilitate bonding
ROLE OF WATER IN BONDING PROCESS
• Water act as a plasticizer for collagen and keep it in soft state.
• If dentin is excessively dried it will leads to collapse of dentin .
• If critical water concentration exists, that prevents collapse of collagen
network and allows expansion of dried dentin.
• Critical amount of water is essential for bonding but an over wet condition
decreases bond strength and formation of blister like structures at the
interface.
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HYBRID LAYER
• This is the zone where the adhesive resin of the dentin bonding agent micromechanically
interlocks within the inter tubular dentin and surrounding collagen fibers
• Hybrid layer is formed in following manner:-
1. Etching removes smear layer and exposes collagen fibers
It also removes hydroxyapetite with in the intertubular dentin
2. Primers penetrate the collagen network.
3. Adhesive resins along with the primers form resin micro tags within the intertubular dentin
• Hybrid layer also called resin-dentin interpenetration/ interdiffusion zone
Scanning electron micrograph of the transition
between composite resin (C)–adhesive (A), adhesive–
hybrid layer (H), and hybrid layer –dentin
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Based on generations
First generation bonding agent
Second generation bonding agent
Third generation bonding agent
Fourth generation bonding agent
Fifth generation bonding agent
Sixth generation bonding agent
Seventh generation bonding agent
Based on smear layer treatment
Smear layer modifying agents
Smear layer removing agents
Smear layer dissolving agents.
Based on number of steps
Three step
Two step
Single step.
EVOLUTION OF DENTIN BONDING AGENTS
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FIRST GENERATION
• Developed in 1960s
• Relied on adhesion to smear layer
• No. of steps involved were two; etching of enamel +
application of adhesive
• Did not recommend dentin etch
• Low bond strength (2–3 MPa).
FIRST GENERATION
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SECOND GENERATION
• Developed in 1970s
• Did not recommend dentin etching
• Low bond strength (4–6 MPa)
• Relied on adhesion to smear layer but some of them employed
• Use of mild cleansing agent
• No. of steps involved were two; etching of enamel + application of adhesive
• Problems with second generation bonding agents:
• Low bond strength
• Unstable interface between dentin and resin because of the insufficient
knowledge about the smear layer.
SECOND GENERATION
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THIRD GENERATION
• Employed the concept of conditioning and
priming before application of bonding agent
• Involved removal or modification of smear layer
• Three steps application, i.e.
• Etching of enamel + Application of primer +
Bonding agent application
• High bond strength and reduced micro-leakage.
THIRD GENERATION DENTIN BONDING SYSTEMS
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THIRD GENERATION USED ACIDS LIKE
2% nitric acid
2.5% maleic acid with HEMA
10% citric acid with 3% ferric chloride
10% phosphoric acid
Eg:- Tenure, Scotch bond, Gluma C&B metabond
FOURTH GENERATION
• They were made available in the mid 1990s.
• Fourth generation bonding agents represent
significant improvements in the field of adhesive
dentistry.
• These agents are based on total etch technique
and moist bonding concept.
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FOURTH GENERATION
• Mechanism of bonding: The fourth “generation” is characterized by the process of
hybridization at the interface of the dentin and the composite resin.
• Hybridization is the phenomenon of replacement of the hydroxyapatite and water
at the dentin surface by resin. This resin, in combination with the collagen fibers,
forms a hybrid layer.
• In other words, hybridization is the process of resin interlocking in the
demineralized dentin surface.
• This concept was given by Nakabayashi in 1982.
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FOURTH GENERATION DENTIN BONDING AGENTS
COMPONENTS OF FOURTH GENERATION DENTIN
BONDING AGENTS
• The fourth generation adhesives consist of:
1. Conditioner (Etchant):
• Commonly used acids are 37 percent
phosphoric acid, nitric acid, maleic
acid, oxalic acid, pyruvic acid,
hydrochloric acid, citric acid or a
chelating agent
• Use of conditioner/etchant causes
removal or modification of the smear
layer, demineralizes peritubular and
intertubular dentin and exposes
collagen fibrils
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COMPONENTS OF FOURTH GENERATION DENTIN BONDING
AGENTS (CONTD.)
• Primer: consist of monomers like HEMA (2-Hydroxyethyl methacrylate) and 4-META
(4-Methacryloxyethyl trimellitate anhydride) dissolved in acetone or ethanol
• they have both hydrophilic as well as hydrophobic ends which have affinity for the
exposed collagen and resin respectively
• primer increases wettability of the dentin surface, bonding between the dentin and
resin, and encourages monomer infiltration of demineralized peritubular and
intertubular dentin.
• Adhesive: The adhesive resin is a low viscosity, semi filled or unfilled resin which
flows easily and matches the composite resin. Adhesive combines with the monomers
to form a resin reinforced hybrid layer and resin tags to seal the dentin tubules
COMPONENTS OF FOURTH GENERATION DENTIN BONDING
AGENTS
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FIFTH GENERATION DENTIN BONDING AGENTS
• Developed in mid 1990s
• Uses two steps, i.e. Total etching + Application of
primer and bonding agent
• Primer + Bonding agent are available in single bottle
• High bond strength
• Easy to use
• Reduced postoperative sensitivity
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FIFTH GENERATION DENTIN BONDING AGENTS
• The basic differences between the fourth and fifth generation dentin bonding
agents is the number of basic components of bottles.
• The fourth generation bonding system is available in two bottles, one
consisting of the primer and the other the adhesive, the fifth generation
dentin bonding agents are available in one bottle only.
• This makes the fifth generation bonding agents simpler and faster than
the fourth generation systems
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SIXTH GENERATION DENTIN BONDING AGENTS
• Self-etching primer and adhesive:
• Available in two bottles:
• Primer
• Adhesive
• Primer is applied prior to the adhesive
• Water is the solvent in these systems.
• Self etching adhesive
• Available in two bottles:
• •Primer
• Adhesive
• A drop from each bottle is taken, mixed and applied to the tooth surface, for example,
Prompt L-pop.
• Mechanism of bonding: In these agents as soon as the decalcification process starts, infiltration
of the empty spaces by the dentin bonding agent is initiated
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ADVANTAGES OF SELF ETCHING PRIMERS
• Comparable adhesion and bond strengths to enamel and dentin
• Reduces postoperative sensitivity becausee they etch and prime simultaneously
• They etch the dentin less aggressively than total etch products
• The demineralized dentin is infiltrated by resin during the etching process
• Since they do not remove the smear layer, the tubules remain sealed, resulting in less
sensitivity
• They form a relatively thinner hybrid layer than traditional product which results in complete
infiltration of the demineralized dentin by the resin monomers. This results in increased bond
strength
• Much faster and simpler technique
• Less technique sensitive as fewer number of steps are involved for the self etch system
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• Bond strengths to enamel are typically lower than for total-etch adhesives.
• Some materials do not adequately etch uncut enamel.
• Bond strengths to auto-curing composites are poor.
• Clinical performance not yet time proven; bond durability questionable, especially for all-in-one
types (hydrolysis).
• The bond strength to dentin and enamel is lower than the fourth and fifth generation system.
DISADVANTAGES OF SELF-ETCHING PRIMERS
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SEVENTH GENERATION BONDING AGENTS
• They achieve the same objective as the sixth generation systems
except that they simplified the multiple sixth generation materials
into a single component, single bottle one-step self-etch adhesive,
thus avoiding any mistakes in mixing.
• Developed in late 2000s
• All in one concept, i.e. components available as single component
• Uses self etch primer
• Good bond strength
• No postoperative sensitivity.
SEVENTH GENERATION BONDING AGENTS
• Seventh generation bonding agents also have disinfecting and desensitizing
properties. They have attained consistently lower bond strengths than the
fourth and fifth-generation adhesives.
• Both the sixth and seventh generation adhesives are self etching, self priming
adhesives which are minimum technique sensitive. The seventh generation
DBAs have shown very little or no postoperative sensitivity.
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SEVENTH GENERATION BONDING AGENTS
• Dual cured self etched adhesive for direct and indirect restoration
with self-, light-, and dual cured resin material
EIGHTH GENERATION BONDING AGENTS
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SMEAR LAYER MODIFYING AGENTS
Adhesive which modify the smear layer and incorporated into the bonding process.
They require one or two steps.
The use single adhesive or primer and adhesive.
E.g.
One step
- Prime and bond 2.1
Two step
- Optec universal bond
SMEAR LAYER REMOVING AGENTS
Adhesive which completely removes the smear layer are subdivided into two and
three step application.
A two step process involves dentin conditioning followed by combined primer and
adhesive whereas a three step process involves separate conditioning priming and
bonding application.
Multiple bottle
e.g. All bond 2, Scotchbond multipurpose
One bottle
e.g. OptiBond SOLO
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SMEAR LAYER DISSOLVING AGENTS
Adhesive which remove smear layer rather than remove it.
The process is accomplished in two steps using a combined conditioner
and primer (self etching primer) followed by application of adhesive resin.
Advantages:
No rinsing
Quick application
HYBRID LAYER AND HYBRIDIZATION
• A dentin bonding agent is a low viscosity unfilled or semifilled resin
for easy penetration and formation of a hybrid layer.
• When a bonding agent is applied, part of it penetrates into the
collagen network, known as intertubular penetration and the rest
of it penetrates into dentinal tubules called intratubular
penetration.
• In intertubular penetration, it polymerises with primer monomers
forming a hybrid layer/resin reinforced layer
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HYBRIDIZATION (GIVEN BY NAKABAYACHI IN 1982)
• Hybridization is the process of formation of a hybrid layer.
• The hybrid layer is the phenomenon of formation of a resin
interlocking in the demineralized dentin surface. The hybrid layer is
responsible for micromechanical bonding between tooth and resin
HYBRIDIZATION (GIVEN BY NAKABAYACHI IN 1982)
Diagrammatic representation of hybrid layer
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HYBRIDIZATION (GIVEN BY NAKABAYACHI IN 1982)
• When dentin is treated with a conditioner, it exposes the collagen
fibril network with interfibrillar microporosities. These spaces are
filled with low viscosity monomers when primer is applied.
• This layer formed by demineralization of dentin and infilteration of
monomer and subsequent polymerization is called the hybrid
layer.
• Hybridoid layeris that area of demineralized dentin into which
resin fail to penetrate
ZONES OF THE HYBRID LAYER
1. Top layer: Consists of loosely arranged collagen fibrils and
interfibrillar spaces filled with resin.
2. Middle layer: Consists of interfibrillar spaces in which
hydroxyapatite crystals have been replaced by resin
monomer because of the hybridization process.
3. Bottom layer: Consists of almost unaffected dentin with a partly
demineralized zone of dentin
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SMEAR LAYER
• Basically, when a tooth surface is altered using hand or rotary instruments, cutting debris are smeared
on the enamel and dentin surface, this layer is called the smear layer
STRUCTURE
• Smear layer has an amorphous, irregular and granular appearance.
• Cameron (1983) and Mader (1984) described that smear layer
consists of two separate parts:
• 1. One superficial and loosely attached to the underlying dentin
• 2. The other consisting of plugs of dentinal debris in the orifices of
dentinal tubules
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DEPTH
• The smear layer has an average depth of 1 to 5 µm but in the dentinal
tubules, it may go up to 40 µm. The depth of the smear layer depends on
following factors:
• Dry or wet-cutting of the dentin
• Type of instrument used
• Chemical composition of irrigating solution when doing root canal treatment.
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COMPONENTS OF THE SMEAR LAYER
• The inorganic material in the smear layer is made-up of tooth
structure and some nonspecific inorganic contaminants
• The organic components may consist of heated coagulated
proteins (gelatin formed by the deterioration of collagen heated by
cutting temperature), necrotic or viable pulp tissue and
odontoblastic processes, saliva, blood cells and microorganisms
ROLE OF THE SMEAR LAYER
• The smear layer is apparently responsible for:
• Acting as a physical barrier for bacteria and bacterial products
• Restricting the surface area available for diffusion of both small and large
molecules
• Resistance to fluid movement
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DISADVANTAGES OF THE SMEAR LAYER
• Bonding to the smear layer forms a weak union because the
smear layer can be torn away from the underlying matrix.
• Since this layer is nonhomogeneous and a weakly adherent
structure, it may slowly disintegrate, dissolving around a leaking
filling material, thus creating a void.
DISADVANTAGES OF THE SMEAR LAYER
• Smear layer on root canal walls acts as an intermediate physical
barrier and may interfere with adhesion and penetration of sealers
into dentinal tubules
• The prescence of a smear layer causes possibility for leakage of
microorganisms and a source of substrate for bacterial growth
• Presence of viable bacteria which may remain in the dentinal
tubules and make use of the smear layer for sustained growth and
activity
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CONCLUSION
• ADHESIVE DENTISTRY HAS REVOLUTIONIZED RESTORATIVE DENTAL
PRACTICE DURING PAST 30 YEARS. TODAY, WE ALL ARE IN THE AGE
OF ADHESIVE DENTISTRY. IMPROVED ADHESIVE MATERIAL HAVE
MADE RESIN BASED COMPOSITE RESTIORATION MMORE RELIABLE
AND LONG STANDING
REFERENCES
CLINICAL OPERATIVE DENTISTRY- PRINCIPLES AND PRACTICE – RAMYA RAGHU
CRAIG’S RESTORATIVE DENTAL MATERIALS
OPERATIVE DENTISTRY – VIMAL.K.SIKRI
STURDEVANT’S ART & SCIENCE OF OPERATIVE DENTISTRY
PHILLIPS' SCIENCE OF DENTAL MATERIALS
