EFFECT OF BLOOD CONTAMINATION USING SELF-ETCHING SELF-ADHESIVE FLOWABLE COMPOSITE AND NANOHYBRID COMPOSITE ON THE SHEAR BOND STRENGTH TO DENTIN – AN IN-VITRO STUDY

*Dr. Harshita Karwatkar, Dr. Vartul Dwivedi, Dr. Sanjeev Kumar Tyagi, Dr. Diya Gilla, Dr. Pratibha Mishra, Dr. Ushma Sharma

ABSTRACT

Background: Shear bond strength (SBS) is a key factor in the success of restorative materials, reflecting their
adhesion to dentin. Blood contamination can interfere with resin infiltration and compromise bonding. Self-etching
self-adhesive flowable composites offer ease of application, while nanohybrid composites provide superior
mechanical properties. Comparing their SBS under uncontaminated and contaminated conditions helps assess their
clinical performance. Aim: To compare and evaluate the shear bond strength (SBS) of self-etching self-adhesive
flowable composite and nanohybrid composite to dentin under uncontaminated conditions and after contamination
with blood. Materials and Methods: Sixty extracted human premolars were prepared with standardized Class V
cavities and divided into two groups: uncontaminated, and blood-contaminated. Each group was subdivided into
two subgroups (n = 15): self-etching self-adhesive composite and nanohybrid composite. SBS was measured using
a universal testing machine. Data were analysed using independent t-test, one-way ANOVA, two-way ANOVA,
Tukey post-hoc test, and Levene’s test. Results: Under uncontaminated conditions, nanohybrid composite showed
significantly higher SBS than self-etch composite (p < 0.001). Blood contamination caused the greatest reduction
in SBS, with self-etch composite performing significantly better than nanohybrid composite (p < 0.001).
Significant differences were observed among subgroups and between factors (p < 0.001). Conclusion: Nanohybrid
composite performs best under ideal conditions, while self-etch composite shows greater resistance to
contamination. Blood contamination has the most detrimental effect on dentin bonding.

Keywords: Shear bond strength, dentin, nanohybrid composite, self-etch composite, contamination, in-vitro study.