Objectives: To detect marginal adaptation of a light curing composite resin to enamel and dentine using different self-etching adhesive systems.
Methods: The class-II cavities with lateral margins in enamel and cervical margins in dentine were filled with Clearfil AP-X (Kuraray, Japan) after application of the following self-etching bonding systems: A – Prompt-L-Pop (3M Espe, Germany), B - SE-Bond (Kuraray, Japan), C - Etch&Prime 3.0 (Degussa, Germany), D - One Up Bond F (Tokuyama, Japan), and E - Syntac classic (Vivadent, Liechtenstein) as control. The marginal integrity of the restorations was detected by SEM analysis of the restorations before (Ø) and after thermo cycling (TC) and after mechanical loading (ML). Statistics: n = 10, Kruskal-Wallis and Mann-Whitney tests.
Results: Percentage frequency of gap formation at the restorations interfaces to enamel and dentine:
|
|
|
A |
B |
C |
D |
E |
|
enamel |
Ø |
18,2 |
0,8 |
7,2 |
13,3 |
1,6 |
|
TC |
51,8 |
1,6 |
41,2 |
30,0 |
2,4 |
|
|
ML |
70,0 |
20,1 |
72,4 |
77,3 |
3,5 |
|
|
dentine |
Ø |
1,5 |
4,6 |
15,7 |
5,9 |
32,1 |
|
TC |
16,0 |
5,7 |
62,6 |
35,3 |
55,2 |
|
|
ML |
22,3 |
12,1 |
75,9 |
61,3 |
82,2 |
The gap rates at the interface to enamel were significantly higher when the self-conditioning bonding systems (A – D) were used in comparison to the acid-etch system (E). The groups A and B showed significantly less gaps than the groups C, D and E at the interfaces to dentine.
Conclusions: Non of the adhesive systems tested provided perfect adaptation over the entire margin length under the conditions of this study. Within the group of self-etching adhesives B was most successful in bonding to both, enamel and dentine. However, the acid-etch multi-step system E showed almost perfect adaptation to enamel but failed in bonding to dentine.