EFFECT OF AMBIENT TEMPERATURE ON FILM THICKNESS AND TENSILE BOND STRENGTH OF A CONVENTIONAL GLASS IONOMER LUTING CEMENT: AN IN VITRO STUDY

*Dr. Samarth Kumar Agarwal, Dr. Romil Singhal, Dr. Sabeeha Hussain, Dr. Kumari Kalpana and Dr. Prakhar Khurana

ABSTRACT

The aim of the study was to evaluate the effect of variation in ambient temperature on film thickness and bond strength of luting GIC. The study was divided into two parts. Each part is divided into three groups according to temperatures; as in group I - 15⁰±2⁰C, group II - 25⁰±2⁰C and group III - 36⁰±2⁰C. For the film thickness, the luting GIC was mixed and placed between the two glass plates and a load of 15 kg was applied for one hour. The space between the glass plates was measured with and without cement by metallurgical microscope at 10x. To evaluate tensile bond strength, extracted permanent mandibular molar was cleaned and prepared with chamfer finish line. Occlusal surface was made flat and the tooth was embedded in auto-polymerized acrylic block. Impression of the tooth was made with copper tube technique and cast was obtained. A casting of dental alloy was fabricated and cemented on the tooth. Tensile bond strength was measured with Instron testing machine. Results showed that the maximum film thickness in group III was 26.78μm, followed by group II 24.52 μm, minimum film thickness was recorded 16.92 μm in group I, a statistical significant difference of p<0.001 was seen. The maximum tensile strength was 6.41 MPa for group I followed by 6.11 MPa for group II and minimum was 5.85 MPa in group III, with a statistical significant differences of p<0.001. Hence it was concluded that ambient temperature affects the film thickness and bond strength of luting GIC.

Keywords: Bond strength, film thickness, glass ionomer luting cement, ambient temperature metallurgical microscope.