Remaining Double Bonds in Light- and Autocure Resins for Splints

Objectives: The aim of this study was to investigate the differences between light curing and autocuring of resins for occlusal splints regarding the quantity of remaining double bonds. Methods: The quantity of remaining double bonds was determined using a fourier transform infrared spectrometer (FTIR technique). Infrared spectra were obtained from uncured and cured resin composites. The following four light curing resins were used: Acrylight, Primosplint, and Triad TranSheet (Colorless and Pink). These resins were cured using the curing oven Targis Power for 10 minutes. Furthermore, the autocuring resin Palapress was used. Two different types of samples were prepared. Sample type A: Cured specimens (n=5 per group) were produced in thin films between two glass plates. In order to investigate the boundary layer phenomenon, both polished and unpolished specimens were used in each case. Sample type B: Occlusal splints (n=5 per group) of all resins were produced in an articulator. Data were statistically analysed using one-way ANOVA with Scheffé test. Results: The quantity of remaining double bonds of the unpolished light-cured resin plates ranged between 19.3–51.9%. Autocuring of Palapress resulted in significantly higher values (41.7%) compared to the light-cured resins Triad TranSheet Pink and Primosplint (p<0.05). The quantity of remaining double bonds of the polished resin plates ranged between 17.7-52.8% and those of the occlusal splints between 11.2-41.8%. For a given resin composite, there were statistically significant differences between the unpolished and polished specimens (p<0.05) but no statistically significant differences between the resin plates and the occlusal splints (p>0.05). Conclusion: Concerning the quantity of remaining double bonds, some light cured resins exhibited significantly lower values than the autocuring resin, suggesting that these materials can be an alternative for occlusal splints.