IADR Abstract Archives
Acid solutions effect of Epigallocatechin-3-gallate and/or Chitosan: dentin mechanical properties
Objectives: To evaluate the effect of experimental phosphoric acids containing Epigallocatechin-3-gallate (EGCG) and/or Chitosan (CH) for improve the durability of resin-dentin bonded interface (adhesion and dentin microhardness), in 2 periods time (24h and 12 months) and with and without mechanical cycle.
Methods: 120 sound molars were polished to expose the superficial dentin and randomized treated according to the groups: (G1) 35% phosphoric acid (Ultra-Etch), (G2) experimental 35% phosphoric acid (EPA), (G3) EPA with chlorhexidine, (G4) EPA with EGCG, (G5) EPA with CH, (G6) EPA with EGCG+CH. After conditioning, was applied adhesive system (Scotchbond Multipurpose Adper) and composite resin (Filtek Z350 XT) according to manufacturer's instructions. Sixty teeth were cycled (60 cycles/minute - 1 Hz, 40N load, 300,000 cycles = 12 months of chewing). Then, the root portion of the all teeth was removed using a cut machine, and the samples were cut in half obtained 2 halves. One of the halves of each tooth was stored individually in containers containing deionized water in a stove at 37°C for 12 months to simulate aging. The other halves were sectioned into dentin beans (0.8mm x 0.8mm) and submitted to analysis of microtensile (n=10, 5 beans/tooth, 0.5mm/min, 50kgf load) and microhardness (n=10, 3 indentations, 10g load, 30s). After 12 months of aging the same methodology was performed for the other halves.
Results: Data were analyzed by ANOVA three-way and Tukey test (p<0.05). Observed that in adhesion the G5 showed worst results and different of G2 and after 1 year G2 and G6 were different of other groups (p<0.05). In microhardness G3 and G6 showed higher microhardness (p<0.05) and after 1 year G6 maintained highest values (p<0.05). The mechanical cycle and time affected negatively the adhesion and microhardness (p<0.05).
Conclusions: Concluded that occurred the improvement stability of adhesion and microhardness of phosphoric acid solution when added EGCG+CH.
Methods: 120 sound molars were polished to expose the superficial dentin and randomized treated according to the groups: (G1) 35% phosphoric acid (Ultra-Etch), (G2) experimental 35% phosphoric acid (EPA), (G3) EPA with chlorhexidine, (G4) EPA with EGCG, (G5) EPA with CH, (G6) EPA with EGCG+CH. After conditioning, was applied adhesive system (Scotchbond Multipurpose Adper) and composite resin (Filtek Z350 XT) according to manufacturer's instructions. Sixty teeth were cycled (60 cycles/minute - 1 Hz, 40N load, 300,000 cycles = 12 months of chewing). Then, the root portion of the all teeth was removed using a cut machine, and the samples were cut in half obtained 2 halves. One of the halves of each tooth was stored individually in containers containing deionized water in a stove at 37°C for 12 months to simulate aging. The other halves were sectioned into dentin beans (0.8mm x 0.8mm) and submitted to analysis of microtensile (n=10, 5 beans/tooth, 0.5mm/min, 50kgf load) and microhardness (n=10, 3 indentations, 10g load, 30s). After 12 months of aging the same methodology was performed for the other halves.
Results: Data were analyzed by ANOVA three-way and Tukey test (p<0.05). Observed that in adhesion the G5 showed worst results and different of G2 and after 1 year G2 and G6 were different of other groups (p<0.05). In microhardness G3 and G6 showed higher microhardness (p<0.05) and after 1 year G6 maintained highest values (p<0.05). The mechanical cycle and time affected negatively the adhesion and microhardness (p<0.05).
Conclusions: Concluded that occurred the improvement stability of adhesion and microhardness of phosphoric acid solution when added EGCG+CH.