Abstract
BACKGROUND: Heat polymerized acrylic (HPA) resins are known to have high porosity that contributes to increased surface roughness and microcrack formation in stress areas. This facilitates the attachment and growth of polymicrobial biofilms contributing to increased antimicrobial resistance. This research aims to study avocado seeds effect on denture-plaque microorganism mono-species and polymicrobial biofilm on HPA resin. METHODS: This study uses 144 samples (n=144), namely HPA resin discs covered with mono-species and polymicrobial biofilms. The discs are soaked for 8 hours in the 5%, 10%, 15%, 20% avocado seed extract, positive control (alkaline peroxide), and negative control (aquadest). Each disc is shaken with a vortex mixer for 1 minute, and 100 μL is added into 96-well microplates with three times repetition and incubated for 24 hours. A microtiter plate biofilm formation assay is then conducted. The inhibition values are determined from the percentage inhibition value formula which requires absorption values from a microplate reader (595 nm). The research data are analyzed using a univariant test, and a one-way ANOVA test, accompanied by Welch ANOVA on non-homogenous data. RESULTS: In this research, it is found that the MBIC (50) of avocado seed extract against the mono-species of C. albicans (5%), C. glabrata (5%), A. odontolyticus (15%), S. gordonii (15%), S. aureus (10%), while against polymicrobial was 20%. There is a significant effect of soaking HPA resin in avocado seed extract on the inhibition of mono-species and polymicrobial biofilms with a value of p<0.001 (p<0.05). CONCLUSION: The MBIC (50) of avocado seed extract in polymicrobial biofilm group is higher than that in the mono-species biofilm groups. Hence, 20% avocado seed extract is concluded as the effective concentration to inhibit denture-plaque microorganism biofilm.