The Effect of Denture Base Surface Treatments on Microlekage of Soft Lining Materials

Munther Kazanji,Nadia Jaffer

doi:10.33899/rden.2009.9109

Abstract

Aims: To evaluate the effect of two acrylic resin denture base surface trearments on microleakage of 4 soft denture lining materials (Tru–soft, Bony plus, UfiGel–P and Molloplast–B after 2 periods of storage and thermalcycling. Materials and methods: One hundred eighty specimens for microleakage were prepared in a disc shape 30 mm diameter and 4 mm thickness (2 mm for acrylic resin part and 2 mm for soft lining material part). Soft lining materials were bonded to three different groups of acrylic resin surface pretreatments (untreated, sandblasted and monomer treated denture base). These specimens underwent two aging procedures: Storage with two periods (one week and one month), and 500 cycles of thermalcycling inside 2% methylene blue dye. Results: Statistical analysis showed that treating the acrylic resin denture base by sandblasting increased microleakage of silicone–based linings (UfiGel–P and Molloplast–B)and decreased microleakage of acrylic–based linings (Tru–soft and Bony plus) in comparison to untreated denture base, while treating the denture base with MMA monomer positively decreased microleakage for all tested soft lining materials in relation to untreated and sandblasted denture base at one week storage, one month storage and at thermalcycling. Conclusions: For all types of denture base surface treatments, microleakage was inevitable, however, wetting the acrylic resin denture base with MMA monomer was more effective in reducing microkeakage than sandblasted and untreated denture bases.

Highlights

The use of soft denture lining materials is helpful in fabricating removable complete and partial dentures because of their ability to alleviate inflamed mucosa, resulting in a more equal distribution of functional load on denture–bearing tissues and improving the retention of the prosthesis [1], but these materials fail for many reasons, one of them is de–bonding of the lining material from the denture base which may be attributed to the microleakage between them [2].Microleakage defined as: The clinically undetectable passage of bacteria, fluids, molecules and even air between a cavity wall and a restorative material applied to it, this occurs because of a microscopic gap at the interface between the two different materials [3]
Two groups of acrylic resin denture base surface treatments were choosen besides untreated denture base, these were: Sandblasting group in which the acrylic resin denture base specimens were abraded in a sandblasting machine (Gerdent, Syria) using 250 μm aluminium oxide particles at a pressure of 6 bar and a monomer treated group in which the specimens of denture base were wetted by a cotton tipped applicator saturated with MMA monomer three times for 180 seconds
Microleakage values of the tested soft lining materials that were bonded to three denture base surface treatments were analyzed at each aging group separately

Summary

Introduction

The use of soft denture lining materials is helpful in fabricating removable complete and partial dentures because of their ability to alleviate inflamed mucosa, resulting in a more equal distribution of functional load on denture–bearing tissues and improving the retention of the prosthesis [1], but these materials fail for many reasons, one of them is de–bonding of the lining material from the denture base which may be attributed to the microleakage between them [2].Microleakage defined as: The clinically undetectable passage of bacteria, fluids, molecules and even air between a cavity wall and a restorative material applied to it, this occurs because of a microscopic gap at the interface between the two different materials [3]. The use of soft denture lining materials is helpful in fabricating removable complete and partial dentures because of their ability to alleviate inflamed mucosa, resulting in a more equal distribution of functional load on denture–bearing tissues and improving the retention of the prosthesis [1], but these materials fail for many reasons, one of them is de–bonding of the lining material from the denture base which may be attributed to the microleakage between them [2]. A roughened acrylic resin denture base by sandblasting was preferred by some investigators to improve the adhesion to a soft lining material (7 and 8), while methyl methacrylate monomer treatment of the acrylic resin denture base was preferred by others as such pretreatment dissolves some of the outer poly methyl methacrylate network and helps to allow a soft lining material to penetrate deeper into the denture base and produce a more intimate contact and reduction of microleakage [5, 9].

Methods

Results

Conclusion