EVALUATION AND COMPARISON OF SHEAR BOND STRENGTHS OF TWO CERAMIC REPAIR SYSTEMS AFTER TWO DIFFERENT SURFACE TREATMENTS - AN INVITRO STUDY

Objective: To evaluate and compare shear bond strength of two intra oral ceramic repair systems on metal substrate and ceramic substrate and to compare among groups to assess a better ceramic repair system after acid etching and laser surface treatment. Methodology: 40 Nickel chromium and 40 feldspathic ceramic specimens were fabricated and divided into two main groups which were further subdivided into four subgroups based on the repair systems used and surface treatments, which had ten specimens each. Hydrofluoric acid and Erbium-doped Yttrium aluminium garnet laser were used as surface treatments and two intra oral repair systems used were Bisco and Angelus. Bonded specimens were stored in distilled water for 24 hours before being thermocycled at 5?C to 55?C for 300 cycles with a 30-second dwell time. The specimens were stored for an additional 7 days before being subjected to shear force in a universal testing machine with a 10KN load cell at a crosshead speed of 0.5 mm/min. The bond strength values obtained were recorded in MPa and analyzed using independent t test. Results: The shear bond strength values obtained were highly significant for Bisco when compared to Angelus for both the metal and ceramic substrates. Similarly after acid etching and laser surface treatment, Bisco proved to be better. Conclusion:Bisco repair system had significantly higher shear bond strength values when compared to Angelus. Hence it is the preferred choice for intraoral repair of fractured metal ceramic restorations. Er: YAG laser surface treatment is the recommended surface treatment for intraoral repair.