Rationale,aims and objectives:The aim of this in vivo study was to evaluate the clinical 1 year follow-up of silica and flouroapatite reinforced glass carbomer filling material.Materials and Methods:In this study, total of 100 restorations were performed.All cavities were prepared conventionally.Half of the restorations were restored with nano composite resin (TEP) (Tokuyama Estelite, Tokuyama Dental, Japan) and the other half were restored with glass carbomer material (GC) (GCP Dental, The Netherlands). Each restorative material was applied according to the manufacturer’s instructions. Restorations were evaluated with modified USPHS criteria at the end of the first week, 6 months and 12 months.Data were analyzed using Fisher’s Exact Chi-Square test, Fisher Freeman Halton Test and Continuity (Yates) Correction.Wilcoxon sign test was used for intra-group comparisons of the parameters.Statistically significance was evaluated at p <0.05.Results:When the filling materials were compared with each other, statistically significant difference was observed at the 12th month on the marginal discoloration. Statistically significant difference was observed between the two materials in the 6th month on the marginal adaptation (p<0.05).Conclusions:In view of this results, there is a need to improve the physical properties of the GC filling material and further in vivo study. Clinical Relevance:Due to not provide good marginal sealing for Class II cavities, it is suggested that GC systems are applied to Class I cavities for now. Key Words; Glass-carbomer; Glass-ionomer cement; Resin composite; Clinical trial ClinicalTrials.gov Identifier: NCT04127929 (16.10.2019)