Effects of cleaning agents and Candida Biofilms on dental resin integrity

The effects of Candida albicans biofilm growth under treatment with cleaning agents on the deterioration of denture acrylic resin (PMMA) and a nano-filled restorative composite resin were examined in vitro.

A total of 240 PMMA (Travelon™) and nano-filled composite (Filtek™ Z350XT) specimens were fabricated. Baseline surface hardness VHN, arithmetic mean surface roughness (Sa, in nm), and flexural strength (ISO 20795-1) were measured. The specimens underwent a Candida albicans ATCC 10231 biofilm challenge for 90 days and were then immersed in 1% sodium hypochlorite (NaOCl) or 15% aqueous patchouli extract (Pogostemon cablin). Power analysis (α = 0.05, power = 80%) was used to determine sample sizes and effect sizes, and partial eta-squared (η²) was calculated for all significant comparisons.

In comparison to PMMA (98.60 ± 0.55 VHN; p < 0.001, η² = 0.92), the nano-filled composite showed significantly greater baseline hardness (156.67 ± 0.58 VHN) and surface smoothness (Sa = 75.60 ± 5.20 nm vs. 256.30 ± 18.50 nm; p < 0.001, η² = 0.89). Greater PMMA surface roughness was associated with significantly higher biofilm accumulation and mechanical deterioration (14.14% flexural strength decrease; p < 0.001). Significant degradation occurred after exposure to NaOCl, and PMMA showed the greatest flexural strength loss (36.13%; p < 0.001). In contrast, no significant material degradation was observed with patchouli extract (p > 0.05). Both disinfectants demonstrated limited efficacy against mature biofilms, whereas NaOCl was highly effective against planktonic C. albicans.

In comparison to PMMA, nano-filled composite had superior surface and mechanical properties associated with enhanced resistance to chemical and biofilm-related deterioration. However, the constraints of the mono-species model warrant potential clinical consideration. NaOCl demonstrated substantial antifungal activity but was associated with severe material degradation, whereas patchouli extract preserved material integrity but exhibited modest anti-biofilm efficacy. Therefore, material-specific cleaning protocols might be warranted. Further investigation of complex models is necessary to balance antimicrobial effectiveness against long-term prosthetic durability.