Evaluation of the remineralising capacities of modified saliva substitutes in vitro

ObjectiveIn this in vitro study the effects of various calcium and phosphate additions to a commercially available saliva substitute on remineralisation of demineralised dentin were investigated.DesignBovine dentin specimens (n = 70) were prepared. Before and after demineralisation (37 °C, pH 5.0, 5 days), one-quarter of each specimens surface was covered with nail varnish (control sound/demineralised tissue). Specimens were exposed either to original Saliva natura (SN 0) or to three modified versions (SN 1, SN 2 and SN 3) formulated with different degrees of saturation with respect to octacalciumphosphate (OCP) and dicalcium phosphate dihydrate (DCPD) for 2 and 5 weeks (37 °C). An aqueous solution (Buskes remineralising solution) served as positive control (PC). Differences in mineral loss (deltadeltaZ) and lesion depth (deltaLD) before and after storage were evaluated from microradiographs.ResultsAfter both storage periods dentin specimens immersed in SN 0 revealed significantly higher mineral losses (indicated by deltadeltaZ) and higher lesion depths (indicated by deltaLD) compared to all other solutions (p < 0.05; ANOVA). Specimens stored in SN 1 and 3 showed significantly higher mineral losses compared with PC (p < 0.05). No differences could be observed between SN 2 and PC (p > 0.05). Only SN 2 significantly remineralised from 2 to 5 weeks storage (p < 0.05; t-test).ConclusionsAn experimental Saliva natura solution (SN 2) with SOCP = 2 and SDCPD = 1.4 showed highest remineralising capacity. Similar or better remineralisation could not be achieved with slightly higher or lower saturated solutions.