The effect of two types of disinfectant on shear bond strength, hardness, roughness of two types of soft liners

Abstract

Background: Poor oral hygiene results in accumulation of dental plaque and dental biofilms, especially in elderlywith denture, regular cleaning of the dentures using chemical or physical methods can minimize the risk of(stomatitis) in denture users. The aim of this study was to evaluate the effect of two types of disinfectant on somemechanical properties of two types of soft liners.Materials and methods: 180 specimens from 2 types of soft liners (Mollosile, Viscogel) were prepared and divided into2 major groups, mollosile group, viscogel group for each test and each major group is divided into 3 subgroups, eachsubgroup includes 10 specimens. Hardness and roughness test specimens were consist of two discs, acrylic disc withdimensions(4mm,15mm)thickness, diameter respectively and soft liner disc with dimensions (2mm,15mm) thickness,diameter respectively. For shear bond test, specimens were prepared from two blocks of acrylic measuring (75mm,25mm, 5mm)length, width, depth respectively with stopper (3mm) and handle of (13mm) thickness and soft linermaterial in the space between the two acrylic blocks. All specimens were stored in distilled water for 24 hours at 37Cothen they were immersed into water(control group) , Solo, Chlorhexidine 0.2 % disinfectant (test groups) for 8 hours tosimulate the weekly exposure time of soft liner with disinfectant. A profilometer device was used to measure theroughness property and Shore A for hardness property and Micro-computer controlled electronic universal testingmachine for shear bond property.Results: The results revealed that there was a significant difference in roughness mean values for each soft liner afterimmersed in disinfectant solutions while there was no significant difference in mean values of (hardness, shear bondstrength) for each soft liner after immersed into disinfectant solutions.Conclusion: Disinfectant solutions (SOLO, CHLORHEXIDINE) had no effect on hardness and shear bond strength of softliners (MOLLOSILE, VISCOGEL) while they had effect on surface roughness by decreasing the surface roughness ofthese soft liners which is a favorable condition.