The Effect of Silicone Soft Denture Liner Immersion in Alkaline Peroxide and Sodium Hypochlorite cleanser on Hardness and Surface Roughness

Abstract

Soft denture liner applied in the intaglio surface of a denture base which directly touches the problematic ridge or mucosa,
functioning as a cushion for a cushioning effect, absorbing pressure and distributes balanced and equal pressure to the tissue
under it, helps with denture retention and as a conditioner on tissues that experience trauma. SDL usage for a long term period
can cause a lot of problems like its soft properties, bonding failure between SDL and denture basis, formation of porosity,
discoloration, solubility and microorganism colonialization. The change of physical and mechanical properties of SDL materials
can be caused by daily denture cleaning with immersion in chemical cleanser liquid like alkaline peroxide and sodium
hypochlorite 0,5%. This study aims to observe the effects of immersion in alkaline peroxide and sodium hypochlorite 0,5% to
self-cured and heat-cured silicone SDL surface hardness and roughness. 24 self-cure silicone SDL (mollosil) and heat-cured
(Molloplast B) samples made by a custom made metal mould with a 15 mm diameter and 10 mm height. Hardness
measurement samples (n=12) and surface roughness samples (n=12). The samples are divided into 3 groups (n=4) and preimmersed in Bi distilled water for 24 hours, stored in incubator at 370 C temperature as a simulation of the oral cavity. The
grouped samples are then immersed in alkalineperoxide, sodium hypochlorite 0,5% liquid cleansers, and Bi distilled water as a
negative control for an estimated time of 1 year. Surface hardness is measured using Shore A Durometer, SHU (shore hardness
unit) and surface roughness is measured using Atomic Force Microscope (AFM) in micrometers (µm). Data analysis results by
ANOVA shows that the effects of immersing self-cured and heat-cured silicone SDL on the three liquid cleaners; Bi distilled
water, alkaline peroxide, and sodium hypochlorite 0,5% to hardness and surface roughness is insignificant. The result of this
study concludes that self-cured and heat-cured silicone SDL immersion on alkaline peroxide, and sodium hypochlorite 0,5% is
safe to use as denture cleansing method because it will not alter physical and mechanical properties on both types of soft
denture liners.