Microbial leakage and marginal adaptation of alkasite restorative material in Class II cavities: an in vitro study

This study aimed to determine the relationship between the interfacial properties of proximal cavities (microbial leakage and marginal adaptation) and restorative materials (alkasite, resin composite, and glass hybrid).

This study involved 66 human third molars that were left intact. Standardized Class II cavities were done on the mesial surface. The samples were then divided into five groups: (i) Cention N (CN, Ivoclar Vivadent), (ii) Filtek Z350XT (FZ, 3M ESPE), (iii) EQUIA Forte (GC Corporation), and (iv) two controls. For 40 days, a dual-chamber model containing Streptococcus mutans was used to study microbial leakage. Qualitative assessments of the sectioned samples were also carried out using a scanning electron microscope (SEM). Moreover, this study employed descriptive and Kaplan-Meier analyses, alongside a one-way analysis of variance for additional descriptive comparisons (p < 0.05).

Across different restorative materials, notable variations in microbial leakage were recorded. From the supplementary analysis between CN and FZ, a statistically significant difference was demonstrated (p = 0.037). In comparison to other restorative systems, CN also produced a prolonged mean time before microbial leakage occurred. For the interfacial properties of the restorative systems, illustrative information was offered via the SEM images.

Regarding microbial leakage, all restorative systems presented their occurrence (despite the constraints of this study). When assessing CN and FZ restorative systems, a slower rate of microbial leakage was also concluded for CN. For the tooth-restoration interface, qualitative data were verified through SEM observations.