ABSTRACT
OBJECTIVE: This study aimed to investigate the microtensile bond strength (µTBS), microleakage, and antibacterial effect of bulk fill resin composite with alkaline fillers (alkasite) (alkaline fillers such as barium aluminum silicate glass and ytterbium trifluoride) in comparison to incremental nanohybrid resin composite. MATERIALS AND METHODS: µTBS was evaluated by using 30 human mandibular molars. Teeth were randomly divided into three groups (C): nanohybrid resin composite (C0), self-cured alkasite (C1), and dual-cured alkasite (C2). Each group was subdivided into two subgroups according to the bulk thickness: 4 mm (T1) and 6 mm (T2). The occlusal enamel of teeth was removed and the resin composite was applied to a flat dentin surface. Then, teeth were sectioned into beams to be tested under tension. For microleakage testing, mesio-occlusal class II cavities were prepared in 15 molars and divided into three groups as mentioned before. Following this, cavities were restored, thermocycled, immersed in a dye, sectioned mesiodistally, and then dye penetration was assessed. The antibacterial effect of both tested materials was evaluated using agar disc diffusion and broth dilution methods against chlorhexidine as a control positive group. RESULTS: There was no significant difference in µTBS between all tested groups. Bulk fill self-cured alkasite showed the lowest microleakage value followed by bulk fill dual-cured alkasite and incremental nanohybrid resin composite, respectively. Also, cervical microleakage showed significantly higher mean value than the occlusal one. The antibacterial effect of alkasite was less than chlorhexidine. Alkasite showed maximum broth clarity at lowest tested bacterial concentration. CONCLUSION: Resin composite with alkaline fillers was characterized by good µTBS and marginal integrity with weak antibacterial effect.
ABSTRACT
OBJECTIVE: This study aimed to investigate the efficacy of the Galla chinensis extract (GCE) on early dentin lesion remineralization. MATERIALS AND METHODS: Seventy-two dentin specimens were divided into three groups according to the treatment solution. In group S1, specimens were treated with GCE; in group S2, the specimens were treated with sodium fluoride (NaF); meanwhile, specimens of group S3 were treated with distilled water (DW). Each group was further subdivided into two subgroups according to the treatment time (1 minute and 5 minutes). An in vitro pH-cycling model for 12 days was done. Subsequently, surface microhardness (SMH) of the specimens, elemental analysis, and their micromorphological appearance were evaluated. STATISTICAL ANALYSIS: Data were statistically analyzed. One-way analysis of variance was used to compare numerical (parametric) data between more than two separate groups followed by post hoc Tukey. RESULTS: There was no significant difference between the mean SMH of dentin between NaF and GCE groups. Regarding the time, the 5-minute treatment with NaF and DW groups recorded higher mean SMH value of dentin than the 1-minute treatment group. Meanwhile, for GCE groups, the 1-minute immersion recorded higher mean SMH value than the 5-minute immersion without any significant difference between them. The microhardness results were confirmed by environmental scanning electron microscope and energy dispersive X-ray analysis results. CONCLUSION: GCE could be used as an effective alternative for dentin remineralization.