Methods: Seven provisional self‑curing materials were investigated, four were commercial: Quicktemp2 (QT, Schottlander), Protemp4 (PT, 3M‑ESPE) as composite based resins; Trim (TR, Bosworth) and Snap (SN, Parkell) as poly (ethyl methacrylate), PEM based resins, and three PEM (Lucite International) based experimental materials with different monomers (Sigma‑Aldrich): isobutyl methacrylate (IB), n‑butyl methacrylate (nB) and tetrahydrofurfuryl methacrylate (TH).
PS and exotherm of six specimens (8mm diameter×1mm thickness) per material were studied for 2h at 37oC, using the Bonded‑disk method. The results were statistically analysed (Mann-Whitney Test and Kruskal‑Wallis Test, p<0.05).
Results: There was no significant difference in exotherm of TR (40.54±0.95oC) and SN (41.32±0.82oC), and between QT (39.68±1.15oC) and PT (39.30±0.60oC). PT had a significantly lower exotherm than TR and SN. TH had a significantly lower exotherm (40.15±0.33oC) than SN, and this value was not significantly different from that of QT and TR. Exotherm of SN was significantly higher than the commercial composite based and three experimental TCBs ( TH, IB:38.72±0.30oC and nB:38.88±0.30oC).
PS of SN was significantly higher after 2h (6.67%±0.59) compared with all commercial TCBs. TH had a significantly lower PS after 2h (5.77%±0.54) than the other experimental materials, IB (6.89%±0.43) and nB (6.72%±0.36). There was no significant difference in PS after 2h between TH and the commercial composite resins QT (5.40%±0.16) and PT (5.43%±0.35). TR, SN and TH showed no significant increase in PS with time (5min, 10min and 2h after mixing) but nB, IB, QT and PT showed differences with time.
Conclusion: The Bonded‑disk method shows QT, PT, TR and TH as having low PS. TH emerges as a promising TCB material and merits further research.