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.
Keywords alkasite - microtensile bond strength - microleakage - antibacterial effect
