This document discusses dentin bonding agents. It begins with an introduction noting that proper union between restorative materials and tooth structure is important, as gaps can lead to problems. The document then covers definitions, factors affecting bonding, conditioning and priming of dentin, the different generations of dentin bonding agents, and their mechanisms of action. It discusses the role of water and bonding in other clinical situations. The conclusion states that modern dentin bonding agents have improved through developments like the total etch technique, providing better bonding to dentin. Overall bonding outcomes are better but not yet ideal, and further clinical trials are still needed.

1. CONTENTS
 Introduction
 Definition
 Factors affecting
 Conditioning
 Bonding to dentin
 Priming
 Dentin bonding agents
 Mechanism
 Evolution
 Role of water
 Bonding in other clinical situations
 Additives
 Success/failure
 Water treeing
 Conclusion
 References
DENTIN BONDING AGENTS

2. INTRODUCTION
 Major Problem – Proper Union
 Gap – Create Problems
 Process Of Inventions – Various
Techniques And Modalities
BONDING
Adhesive techniques
Adhesive agents
ADHESIVE
AGENTS
Dentin
hyper
sensitivity
Pit and
fissure
sealants
Beneath
amalgam

3. BASIC PRINCIPLES
Adhesive
Substance added to produce adhesion
Adherend
Material to which it is applied
Adhesion
force or the intermolecular
attraction
Factors affecting
SURFACE ENERGY WETTING CONTACT ANGLE

4. TOOTH AS A SUBSTRATE FOR BONDING
 Contrast in composition of
enamel and dentin influence
the bonding
 Presence of moisture in
dentin
 Dentinal fluid- outward flow
 Moisture – external factors
Important factor – smear layer
Smear unit - contaminant

5. Requisite of an ideal bonding agent
High bond strength to dentin .
Biocompatibility.
Minimize micro leakage.
Prevent recurrent caries and marginal staining.
Easy to use and minimally technique sensitive.
Good shelf life.
Be compatible with a wide range of resins.
Non toxic and non sensitizing.
seal the tooth surfaces from oral fluids.

6. enamel
untouched pellicle
ground
Smear
layer
Pellicle and smear layer
Surface contaminants
Micro organisms
plaque
 Objective – remove contaminants, raise energy
 Conditioning – remove organic layer
 Etching – demineralization
 Removes – pellicle & surface enamel
 Creates porous layer
 Increase wettability, surface area & surface energy
Conditioning enamel and etching
Cleaning wash dry Isolate
Acid
application
wash

7. PATTERNS OF ETCHING IN ENAMEL
Etched surface – matt white / frosty
Other alternatives
Recent advances
Resin tags
Micro
tags
Macro
tags
• 37% PA – most common
• Time – 10-15 seconds
etchant
gel
liquid
High fluoride Acid resistant 60 seconds

8. BONDING TO DENTIN
 Comparatively difficult – Complex tissue
 Living tissue
 Direct connection – pulp
 Bonding of resin composite-dentin
 Micromechanical attachment
Treatment of dentin for optimal bonding
Conditioning of dentin
Role of smear layer
Priming
Hybrid layer
resin
Demineralised
Primed
Inter tubular dentin
Effects of
conditioning
chemical
thermal
mechanical

9. DENTIN BONDING AGENTS
Based on
generations
Smear layer
Number of clinical
application steps
and how they
interact
CLASSIFICATION

10. WATER TREEING PHENOMENON
• This phenomenon does not occur in self etching primers because the etched and
primed dentin is covered by a comparatively thick hydrophobic resin layer
• In such a case a resin modified glass ionomer is used before placing composite
restorations.
Water treeing
phenomenon
Remnant
water theory
Water-flux
theory

11. REFERENCES
• Sturdevant’s art and science of operative
dentistry
• Philips science of dental materials
• Pickards manual of operative dentistry
• Materials used in dentistry mahalakshmi
• Buonocore MG, Wileman W, Brudevold F:
Simple methods of increasing adhesion of
acrylic filling materials to enamel surfaces, J
Dent Res 34(6):849, 1955
• Asmussen E: Clinical relevance of physical,
chemical and bonding properties of
composite resins, Oper Dent 10:61, 1985
CONCLUSION
• Dentin bonding agents have dramatically improved in
recent years.
• The major breakthrough has been the “total etch”
technique, in which the smear layer is removed
simultaneously with the enamel etching.
• The primers and bonding agents of multicomponent
systems and combined primer/agent of one-bottle
systems provide a dramatic bond to both the
collagen and etched hydroxyapatite of the dentin.
• Although dentin bonding agents are not yet
considered “ideal” materials, they are certainly close.
Hopefully more controlled clinical trials will be
forthcoming, allowing choices of material and
technique to be made on a sound scientific basis.

12. Thank you