The influence of powder liquid ratio on the flexural strength of fibre reinforced acrylic resin material

Abstract

Introduction: Often the powder liquid (P/L) ratio of polymethyl methacrylate (PMMA) resins is changed to modify the handling properties of the material. While it is known that this may influ­ ence the mechanical properties of unreinforced PMMA resin, little is known about its effect on fibre reinforced resin. Purpose: The purpose of this study was to determine how different P/L ratios influence the flexural strength (FS) of a glass fibre reinforced autopolymerizing PMMA resin used for fabr icating fixed partial dentures. Results: FS values of all reinforced subgroups were significant­ ly higher than the values of the unreinforced subgroups (p<O.OS). Among the 3 unreinforced subgroups the difference in FS was in­ significant (p>O.OS) . Within the reinforced group there was a sig­ nificant difference between the control group, which had a higher median FS value than the two other subgroups (p<O.OS). Conclusion: When reinforcing PMMA resin with glass fibre, it is important to use the recommended P/L ratio. For unrelnforced PMMA resin the P/L ratio can be changed within limits without adverse effects on the FS.