title: The effect of flexible acrylic resin on masticatory muscle activity in implant-supported mandibular overdentures: a controlled clinical trial.
abstract: BACKGROUND
  It is not yet clear from the current literature to what extent masticatory muscle activity is affected by the use of flexible acrylic resin in the construction of implant-supported mandibular overdentures.
  
  
  OBJECTIVE
  To compare masticatory muscle activity between patients who were provided with implant-supported mandibular overdentures constructed from flexible acrylic resin and those who were provided with implant-supported mandibular overdentures constructed from heat-cured conventional acrylic resin.
  
  
  METHODS
  In this clinical trial, 12 completely edentulous patients were selected and randomly allocated into two equal treatment groups. Each patient in Group 1 received two implants to support a mandibular overdenture made of conventional acrylic resin. In Group 2, the patients received two implants to support mandibular overdentures constructed from "Versacryl" flexible acrylic resin. The maxillary edentulous arch for patients in both groups was restored by conventional complete dentures. For all patients, masseter and temporalis muscle activity was evaluated using surface electromyography (sEMG).
  
  
  RESULTS
  The results showed a significant decrease in masticatory muscle activity among patients with implant-supported mandibular overdentures constructed from flexible acrylic resin.
  
  
  CONCLUSIONS
  The use of "Versacryl" flexible acrylic resin in the construction of implant-supported mandibular overdentures resulted in decreased masticatory muscle activity.
authors.affiliation: Fixed and Removable Prosthodontics Department, Oral and Dental Research Division, National Research Centre, Giza, Egypt.
authors.forename: Eman Mostafa Ahmed
authors.initials: EM
authors.lastname: Ibraheem
authors.affiliation: Department of Prosthetic Dental Sciences, Al Farabi College for Dentistry and Nursing, Riyadh, Saudi Arabia.
authors.forename: Mohammad Zakaria
authors.initials: MZ
authors.lastname: Nassani
keywords: electromyography; flexible acrylic resin; implant-supported overdentures; muscle activity