Comparison of Bond strength between acrylic based soft liner and two different denture bases (3Dprinted and conventional denture base).

Introduction:
Soft lines used in case of sore or atrophied mucosa, alleviate inflamed mucosa and for obturators
after maxillofacial surgery. but These liners have several problems such as the loss of softness,
porosity and poor tear strength, which is of the most serious problems with soft denture liners is
the failure of adhesion between the soft denture liner and the denture 2 That may be lead to failure
as a result.
Material and methods:
The samples were divided into two groups (n =40) according to the type of denture base materials:
Group I: 3D printed denture base with Acrylic based soft liner (Acrostone Dental &
Medical Supplies), Group II: heat cured acrylic denture base with Acrylic based soft liner
(Acrostone Dental & Medical Supplies).
The samples were tested by shear applied by tensile mode of force. samples were tested by
(Instron) the universal testing machine at a crosshead speed of 40 mm/min until complete
separation of soft-liner material from the acrylic plates. The maximum force at the point of failure
leading to separation was recorded.
Result:
Bond strength in Group I (acrylic soft liner with conventional heat cured denture base) showed a statistically significant difference when compare to group II (the acrylic based soft liner to 3D printed denture base)Shows P value of 0.000*.
CONCLUSION
Based on our study findings of this in vitro study, 3Dprinted denture base with acrylic based soft liners had statistically significant lower tensile bond strength values to the conventional heat cured one