Mulder, RiaanNoordien, NaeemahRossouw, Shaun2022-12-052022-12-052019Mulder, R. et al. (2019). In vitro analysis of techniques that alter the surface hardness of a glass ionomer restorative material. The Journal of Contemporary Dental Practice, 20(12), 1362-1366.1526-371110.5005/jp-journals-10024-2702http://hdl.handle.net/10566/8185Ab s t r A c t Aim: The aim of this in vitro study was to compare the eect of dierent manipulation techniques on the surface hardness of ChemFil Rock glass ionomer.Materials and methods: The changes in Vickers surface hardness ( VH) of ChemFil Rock were evaluated after the application of ve manipulation techniques and compared with one control group (n = 60). The manipulation techniques included: nger pressure set, electronic piezo producing a high frequency set, air piezo producing a low frequency set, heat-set achieved with a curing light and the last technique was a combination of electronic piezo followed by heat-set. Standard set was the control.Results: The average surface hardness for the standard set was 49.5 VH. No statistical dierences were demonstrated when the means were compared for nger pressure set (49.2 VH) or the air piezo set (48.49 VH) with standard set. The electronic piezo (54.21 VH) and the heat-set (57.5 VH) had an increased mean surface hardness when compared to other techniques. Heat-set had the highest surface hardness demonstrating a signicant statistical dierence when compared with standard set, nger pressure set, air piezo set as well as the combination of electronic piezo (p < 0.05).Conclusion: The surface hardness of the glass ionomer cement (GIC) material assessed in this study can be predictably improved by applying the heat-set technique. A command set can be achieved with the electronic piezo or the air piezo, however, the surface hardness will only increase with the use of the electronic piezo.enGlass ionomer cementLaboratory researchLED dental curing lightsurface microhardnessUltrasonic scalerArticle