Evaluation of the tensile and peel bond strength of the silicone and acrylic soft liner following denture base surface treatment: An In Vitro study

Harishnath, V (2007) Evaluation of the tensile and peel bond strength of the silicone and acrylic soft liner following denture base surface treatment: An In Vitro study. Masters thesis, Tamil Nadu Government Dental College and Hospital, Chennai.

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Abstract

INTRODUCTION : Denture soreness with associated pain is one of the most alarming situations seen in complete denture wearers. The predisposing causes for denture soreness may vary and depends upon fabrication of the prosthesis and bio-acceptability of denture bearing and supporting tissues. Technical errors such as over extension and under extension of prosthesis can be well managed by correcting these errors. Denture soreness, which occur due to tissue intolerance to the denture particularly in chronic systemic disorders such as diabetes mellitus. Mere correction of the technical errors alone will not be much helpful to treat the denture soreness due to hard acrylic resin bases in debilitating patient. Hard acrylic denture bases are liable to stress the mucosa beyond its physiological levels of tolerance leading to inflammation and resorption. Excessive resorption of the residual ridges may cause impairment of stability of the denture bases, which is accompanied by soreness, pain and discomfort to the patient masticatory system. AIMS OF THE STUDY : 1. To study the tensile and peel bond strength of the auto polymerized acrylic and silicone based soft liners bonded to the heat cure acrylic denture base whose surface is pretreated with methyl metha acrylate. 2. To study the tensile bond strength of the auto polymerized acrylic and silicone based soft liners bonded to the heat cure acrylic denture base. 3. To study the peel bond strength of the auto polymerized acrylic and silicone based soft liners bonded to heat cure acrylic denture base. 4. To study the surface topography of the heat cure acrylic denture base before and after surface pretreatment with methyl metha acrylate by scanning electron microscope. MATERIALS AND METHODS : The present study was conducted to evaluate the peel and tensile bond strength of some of the commercially available soft liners with denture base resin and the effect of surface pretreatment of acrylic denture base with methyl methacrylate. In addition to this the surface topography of the heat cure acrylic denture base is observed before and after surface pretreatment with methyl metha acrylate by scanning electron microscope. TENSILE BOND STRENGTH : A total of 40 acrylic blocks of dimensions 40 x 10 x 10mm were prepared in heat cure denture base resin. The polymethyl metha acrylate blocks were ground with 320-grit silicone carbide paper to remove surface irregularities and excess material. These 40 blocks were then divided into 4 groups : 1. Group A, 2. Group B, 3. Group C, 4. Group D. Each group contains 5samples and each sample consists of two acrylic blocks with soft liner interposed. Group A and C samples surfaces were not treated with methyl metha acrylate. Group B and D samples surface were treated with methyl metha acrylate for 180 seconds. Auto polymerized silicone soft liner were bonded to group A and B. Auto polymerized acrylic soft liner were bonded to group C and D. RESULTS : An invitro study was conducted to evaluate the peel and tensile bond strength of some of the commercially available soft liners with acrylic denture base and the effect of surface pretreatment of denture base with methyl metha acrylate. In addition to this the surface topography of the heat cure denture base is observed before and after surface pretreatment with methyl metha acrylate by scanning electron microscope. Tensile and peel bond strength tests were carried out with a universal testing machine named Lloyed instrument. Five samples from each group were tested at a constant cross head speed of 5mm/min12. The tensile and peel bond strength were recorded. All data’s were tabulated and statistical comparisons were made by one-way ANOVA variance and Tukey-HSD multiple range comparison test. CONCLUSION : Within the limitations of this in vitro study, the following conclusion were drawn: 1. Treating the acrylic denture base surface with methyl metha acrylate for 180 seconds significantly improved the bond strength of silicone based soft liner to the acrylic denture base. Considering the results of both tensile and peel bond strength test together, the use of methyl methacrylate pretreatment for 180 seconds was found to be the most effective method to increase bonding ability of the silicone soft liner to acrylic denture base. 2. The tensile and peel bond strength of acrylic soft liner bonded to pretreated surface of the acrylic denture base doesn’t shows any significant improvement with acrylic soft liner bonded to the untreated surface of the acrylic denture base. 3. The results of scanning electron microscope shows wetting of the acrylic denture base with methyl methacrylate for 180 seconds, smoothened the acrylic denture base surface and the pores on the surface were found to be more prominent than the untreated surface of the acrylic denture base.

Item Type: Thesis (Masters)
Uncontrolled Keywords: tensile, peel bond strength, silicone, acrylic soft liner, denture base surface treatment.
Subjects: DENTAL > Prosthodontics and Crown and Bridge
Depositing User: Kambaraman B
Date Deposited: 19 Jan 2018 01:25
Last Modified: 19 Jan 2018 01:25
URI: http://repository-tnmgrmu.ac.in/id/eprint/5467

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