In vitro evaluation of shear bond strength of nanocomposites to dentin.
OBJECTIVE
To compare the shear bond strength of nanocomposites to dentin using three different types of adhesive systems; and to test few specimens under Scanning Electron Microscope (SEM) for analysing whether the bond failure is adhesive or cohesive.


METHODS
Sixty human premolar teeth were selected and were randomly grouped, with 20 specimens in each group: group 1 - fluoride releasing dentin bonding agent; group 2 - antibacterial containing dentin bonding agent; and group 3 - one step conventional self etch adhesive. Each group was treated with its respective bonding agents, composite resin build up was done, and shear bond strengths were tested using Instron Universal testing machine. Few of the specimens were tested under SEM.


RESULTS
The results were statistically analysed using One-way ANOVA and paired t-test. It was observed that group 3 has the highest shear bond strength followed by group 2, and then group 1. Adhesive failures and mixed failures were most frequent types of failures as seen under SEM.


CONCLUSIONS
Addition of antimicrobial agent decreases the bond strength of dentin bonding agent and addition of fluoride further decreases the bond strength. From SEM results it can be concluded that the zone of failure could not be defined and also that the failure mode was independent of the dentin bonding agent used.
Senior Lecturer, Department of Conservative Dentistry and Endodontics, Ideas Dental College , Gwalior, Madhya Pradesh, India .
Swati
S
Gupta
Senior Lecturer, Department of Conservative Dentistry Dentistry and Endodontics, Malla Reddy Institute of Dental Sciences , Hyderabad, Telangana, India .
Vinay Kumar
VK
Vellanki
Associate Professor, Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Melaka Manipal Medical College , Melaka, Malaysia .
Vikram K
VK
Shetty
Senior Lecturer, Department of Conservative Dentistry and Endodontics, Ideas Dental College , Gwalior, Madhya Pradesh, India .
Sudhanshu
S
Kushwah
Reader, Department of Prosthodontics and Crown & Bridge, Maharaja Ganga Singh Dental College & Research Centre , Sri Ganganagar, Rajasthan, India .
Geeta
G
Goyal
Professor & Head, Department of Conservative Dentistry and Endodontics, Krishnadevaraya College of Dental Sciences , Bangalore, Karnataka, India .
S M Sharath
SM
Chandra
Antibacterial; Dentin bonding agents; Fluorides; Nanocomposites; Self etch adhesives; Shear bond strength; Total etch adhesives