Comparative Evaluation of Microshear Bond Strength of 5(th), 6(th) and 7(th) Generation Bonding Agents to Coronal Dentin Versus Dentin at Floor of Pulp Chamber: An In vitro Study.
BACKGROUND
Lack of seal and adhesion between the final restoration and tooth structure adversely affects the results of root canal treatment. Lots of adhesive bonding agents are marketed to overcome this deficiency and achieve successful restoration. So the study compares and evaluates the micro shear bond strength of coronal dentin and pulp chamber dentin using three different generation dentin bonding systems and to know clinical efficiency for clinical use.


METHODS
DIFFERENT GENERATION DENTIN BONDING SYSTEMS USED WERE: (1) One bottle total etch system (XP Bond-5(th) generation), (2) Two-step self-etch system (Clearfil SE Bond-6(th) generation) and (3) All-in-one system (G Bond-7(th) generation). Thirty human mandibular molars were collected out of which sixty samples were prepared by sectioning each tooth into coronal dentin and pulpal floor dentin. They were divided into two major groups. Group I: 30 Coronal dentin samples. Group II:30 Pulpal floor dentin samples. Both the groups were further subdivided depending on the bonding agent used. Subgroup Ia:XP Bond, Subgroup Ib:Clearfil SE Bond, Subgroup Ic:G Bond, Subgroup IIa:XP Bond, Subgroup IIb:Clearfil SE Bond, Subgroup IIc:G Bond. Resin composite was bonded to these samples and tested for micro-shear bond strength. The mean bond strengths and standard deviations were calculated and analyzed using one-way ANOVA test and Student's t-test (unpaired) and honestly significant difference post-hoc tests.


RESULTS
Coronal dentin showed higher values of micro shear bond strength than the pulpal floor dentin. All-in-one system (G Bond) showed least bond strength values to both the regions coronal dentin and pulpal floor dentin.


CONCLUSIONS
Factors affecting the shear bond strength are dependent on material (adhesive system), substrate depth and adhesive/depth interaction. Hence composition and substrate treatment should be considered for good adhesive. Chemical composition of adhesive system determines clinical successes.
Reader, Department of Conservative Dentistry and Endodontics, KLR'S Lenora Institute of Dental Sciences, Rajahmundry, Andhra Pradesh, India.
Velagala Lakshmi
VL
Deepa
Senior Lecturer, Department of Conservative Dentistry and Endodontics, KLR'S Lenora Institute of Dental Sciences, Rajahmundry, Andhra Pradesh, India.
Bhargavi
B
Damaraju
Senior Lecturer, Department of Conservative Dentistry and Endodontics, St. Joseph Dental College, Eluru, Andhra Pradesh, India.
Bollu Indira
BI
Priyadharsini
Reader, Department of Conservative Dentistry and Endodontics, Lenora Institute of Dental Sciences, Rajamundry, Andhra Pardesh, India.
Vummidisetti V
VV
Subbarao
Professor and Head, Department of Conservative Dentistry and Endodontics, KLR'S Lenora Institute of Dental Sciences, Rajahmundry, Andhra Pradesh, India.
K Rama Krishna
KR
Raju
All-in-one system; coronal dentin; microshear bond strength; pulpal floor dentin; self-etch; total etch