2. Introduction
Advent of composite resin has shifed us to
the age of adhesive dentistry
Adhesives have modified cavity preparation
concept from “ extension for prevention” to
“restriction with conviction” with the
invention of acid etching with 85%
phosphoric acid in 1955 by Bunocore.
3. Adhesion
Refers to micromechanical coupling of
restoration to tooth structure
Dental adhesive system consists of a
conditioner ,primer and bonding agent
5. Ideal Bonding Agent
Eliminates post-operative sensitivity
Thin film thickness
No marginal discoloration
Ease of use
Reasonable shelf life
Bond strength
Moderate cost
(Christenseen 2005)
6. Generations of Adhesives
8 generations :
1st & 2nd without etching
3rd acid etch,separate primer margin staining
4th hybrid layer, concept of wet bonding
5th primer and adhesive in 1 bottle
6th self –etchprimers,decreased
sensitivity,bond strength lower than 5th
7th All in one
8th self-etch self-adhere flowable composite
(Optibond [Kerr]
7. New Classification
Etch and Rinse system
Self –Etch
- Two bottles applied separately
- Two bottles mixed as one solution
- All -in-one
8.
9. Interaction With Dental Hard
Tissues
With Enamel
With Dentin
Quality of dentin bonds thought to be
determined by the depth of demineralization
and extent of the diffusion and impregnation
of the monomer (Tay FR et al 2001)
This zone of exposed collagen may be
unstable and subjected to hydrolysis (Sano H
et al)
10. - To avoid this ,self
etching systems that donot
require smear layer removal
these latest adhesives based
on simplification and
application time (Oper Dent
2003)
28. • Although the smear layer thickness had no
effect on resin-dentin bond strength, thick
smear layers adversely affected the mean gap
width,The etch-and-rinse adhesive systems
showed higher microBS and lower mean gap
widths (Kenshima et al 2005)
• the one-step, low pH, acetone-based self-
etching adhesive promoted the higher bond
strength values, which were statistically
similar to those obtained with the two-step,
water-based self-etching adhesive (Pegado et
al 2010)
29. Glass Ionomer Adhesives
Based on resin-modified GIC
Conditioner polyalkanoic acid hybrid layer
0.5um
The shear bond strength of the glass-ionomer
adhesive to dentin proved to be independent
of the smear layer thickness (El Askary et al
2008)
30. Newer generations of adhesives appear to be
more tolerant of saliva contamination (Dunn
2004)
Shear bond str. & numbers of gap-free
restorations increased significantly with
drying time (Jacobsen et al 2006)
Following a correct application procedure,
the etch-and-rinse, self-etch and self-
adhesive luting agents are equally effective in
bonding to enamel and dentin (Van Merbeek
2007)
31. Wettability is similar between self-etching
and total-etch adhesives.The smear layer
affects slightly the wettability of self-etching
adhesives (Rosales et al 2008)
Enamel bonding was generally more effective
with phosphoric-acid etching. Enamel
bonding performance of 2-step self-etching
adhesives was improved when phosphoric
acid was applied on enamel selectively
(Frankenberger et al 2008)