Effect of Using Fiber Reinforcement Ribbond® System on Marginal Adaptation of Fluoride Releasing Restorations: An In Vitro Study

Abstract

Aim: To assess the impact of using Ribbond® fibers on the marginal adaptation of three Giomer restorative materials at the gingival margin in class II restorations.Materials and Methods: Three Giomer restorative materials were evaluated; BEAUTIFIL II (SHOFU INC., Kyoto, Japan), BEAUTIFIL II LS (SHOFU INC., Kyoto, Japan), BEAUTIFIL-Bulk Restorative (SHOFU INC., Kyoto, Japan). Sixty human mandibular molars were collected. Standardized occluso-mesial box-only cavities were prepared. The cavities were allocated into 6 groups (n = 10) according to the type of restorative material; Group 1: Nanohybrid Giomer: BEAUTIFIL II (BE), Group 2: Low-shrinking nanohybrid Giomer: BEAUTIFIL II LS (BLS), Group 3: Bulk-fill Giomer: BEAUTIFL-Bulk Restorative (BBR), Group 4: Nanohybrid Giomer: BEAUTIFIL II + Fiber Reinforcement Ribbond® System (BE+R), Group 5: Low-shrinking nanohybrid Giomer: BEAUTIFIL II LS + Fiber Reinforcement Ribbond® System (BLS+R), Group 6: Bulk-fill Giomer: BEAUTIFL-Bulk Restorative + Fiber Reinforcement Ribbond® System (BBR+R). All restorations were thermocycled for 10,000 cycles between 5°C-55°C. Scanning electron microscope (SEM) was used to analyze the gingival margins of the restorations at 50× magnification to determine the length of the gap (non-continuous) margin. Shapiro-Wilk test, two way analysis of variance (ANOVA) test and Sidak’s multiple comparisons test were used to analyze the results statistically. Results: The mean percentage of non-continuous margins for the groups was as follows: BE (29.47±1.88), BLS (28.59±1.74), BBR (12.30±1.43). BE+R (15.44±1.31), BLS+R (10.70±0.92), BBR+R (15.20±0.99).Conclusions: The use of Ribbond® fibers improves the marginal adaptation at the gingival margins of class II of incrementally-packed Giomer restorative materials.