Changes in roughness of denture base and reline materials by chemical disinfection or microwave irradiation: surface roughness of denture base and reline materials

Objective

The effect of disinfection by immersion in sodium perborate solution and microwaveirradiation on surface roughness of one denture base resin (Lucitone 550 -L), 3hard chairside reline resins (Tokuyama Rebase II-TR, New Truliner-NT, Ufi Gelhard-UH) and 3 resilient reline materials (Trusoft-T; Sofreliner-S, Dentusil-D)was evaluated.

Material and methods

Thirty specimens of each material were made and divided into 3 groups: Control -not disinfected; P - daily disinfection by immersing in sodium perborate solution(3.8%); MW - microwave disinfection (6 min/650 W). Roughness measurements weremade after polymerization (baseline) and after 1, 3 and 28 days. Roughnessdifferences relative to the baseline readings were analyzed by Student''s t-test(P=0.05).

Results

At baseline, Trusoft showed the highest (P<0.001) mean surface roughness (3.54µm), and its surface roughness was significantly reduced after 28 days ofdisinfection by immersion in sodium perborate (P=0.013). Roughness measurements ofmaterial Trusoft were not performed after microwave disinfection due to the severealterations on the surface. In the 3 groups evaluated, changes in roughness weresignificant for materials Ufi Gel hard (from 0.11 to 0.26 µm; P≤0.041) and NewTruliner (0.19 to 0.76 µm; P≤0.019). The roughness of materials Lucitone 550 (0.37µm), Tokuyama Rebase II (0.37 µm), Sofreliner (0.49 µm) and Dentusil (0.38 µm)remained unaffected (P>0.05).

Conclusions

The roughness of the hard reline materials Ufi Gel hard and New Truliner wasadversely affected by microwave disinfection, immersion in water or in sodiumperborate. Microwave disinfection caused severe alterations on the surface of theresilient liner Trusoft.