COMPARING THE MARGINAL DISCREPANCY AND FRACTURE RESISTANCE OF DIFFERENT CERAMIC VENEER PREPARATION DESIGNS AND ASSESMENT OF MICROTENSILE BOND STRENGTH BETWEEN NORMAL AND FLUOROSED TEETH – AN IN VITRO STUDY.

DR. R. HIMABINDU; DR. B. PRASAD

Volume : VIII, Issue : IV, April - 2019

COMPARING THE MARGINAL DISCREPANCY AND FRACTURE RESISTANCE OF DIFFERENT CERAMIC VENEER PREPARATION DESIGNS AND ASSESMENT OF MICROTENSILE BOND STRENGTH BETWEEN NORMAL AND FLUOROSED TEETH – AN IN VITRO STUDY.

Dr. R. Himabindu, Dr. B. Prasad

Abstract :

PURPOSE OF THE STUDY: To compare the marginal discrepancy and fracture resistance of porcelain laminate veneers faicated with three different tooth preparation designs and assessment of micro tensile bond strength of veneers prepared on normal and fluorosed teeth with the same preparation design. MATERIALS AND METHODOLOGY: 50 extracted maxillary teeth were collected, 40 normal and 10 fluorosed teeth. Three different preparation designs were chosen for 30 normal tooth samples. Group I (n=10) is with Window preparation design, Group II (n=10) with Butt joint preparation and Group III (n=10) with Incisal overlap design. Remaining 20 samples are to be tested for Micro Tensile Bond Strength between Group A (n=10, normal teeth) and Group B (n=10, fluorosed teeth) with only Incisal overlap design . Veneers were faicated with IPS Empress Esthetic Ingots. The first 30 samples are tested with Stereomicroscope for assessment of marginal discrepancy followed by measurement of fracture resistance with Universal Testing Machine at an angle of 45⁰. Micro Tensile Bond Strength is evaluated in between Normal and Fluorosed teeth with Universal Testing Machine. RESULTS: Highest marginal discrepancy value of ceramic veneers was found in the Incisal overlap preparation (Group 3) at both incisal and cervical areas and least found with Butt joint preparation (Group 2). Fracture resistance was least in Window preparation (Group 1) and highest in Incisal overlap preparation (Group 3). There is statistically significant difference found between all the three groups. Values from Micro Tensile Bond Strength test between veneers on normal (group A) and fluorosed teeth (Group B) did not result in any statistical significant values . CONCLUSION: Marginal discrepancy was minimal in Butt joint preparation. Fracture resistance was significant with Incisal overlap design though it had higher marginal discrepancy. Presence of fluorosis did not influence the bond strength values between normal and fluorosed teeth.