Evaluation of Superficial Micro hardness of two Composite Resins

Objective: To evaluate the superficial micro hardness, compeering the effect of two curing lights –Optilux401- Halogen (Demetron) and UltraLume 5 – Leds (Ultradent) and two composite resins – Z250/with camphoroquinone (3M ESPE) and Pyramid/ without camphoroquinone (Bisco) after 24 h of the preparation the of the specimens. Material and Methods: Metallic matrices were made, having an interning cavity with 2mm of thickness and 5 mm of diameter. Five specimens were made for each study group. Of specimens were photo polymerized in one increment for 40 seconds. The micro hardness machine MMT-3 (Bueheler) with a load of 50gf for 30 seconds, making eight impressions in the top and eight in the base. Results: G1 (Z250/Demetron/top) 69.125 +/- 7.959 HV; G2 (Z250/Demetrom/base) 63.803+/- 9.981 HV; G3 (Pyramid/Demetron/top) 58.215+/-5.773 HV; G4 (Pyramid/Demetron/base) 52.556+/-3.529 HV; G5 (Z250/UltraLume5/top) 67.853+/- 6.783 HV; G6 (Z250/ UltraLume5/base) 43.820 +/- 7.666; G7 (Pyramid/UltraLume5/top) 57.308+/- 6.512 HV and G8 (Pyramid/Ultralume5/base) 43.820+/-6.511 HV. The ANOVA test and Turkey HDS test were applied and demonstrated significant differences in the micro hardness Vickers considering all groups (p < 0,0001). Conclusion: G1 and G5 had the highest results; G4 and G8 presented the lowest; the micro hardness Vickers for G2, G3, G6 and G7 groups had similar results in the relation of composite resins that were used, the presences of camphoroquinone gave higher values of micro hardness. (Investigation realized with the support of PIBIC/UEPG).