title: A comparative evaluation of impact strength of conventionally heat cured and high impact heat cured polymethyl methacrylate denture base resins: an in vitro study.
abstract: The denture bases made by using polymethyl methacrylates of Acrylic resin family have excellent physical properties, simple to process and easy to reline, rebase and repair. One of the inherent disadvantages of this material is the liability to break during function. The strength assessment of acrylic resins have been made generally by transverse defection tests.
  
  
  OBJECTIVE
  To evaluate the impact strength valves of certain brands of commercially available denture base resins and suggest their suitability.
  
  
  METHODS
  The denture bases we made using polymethyl methacrylates of acrylic resin family because they have excellent physical properties, simple to process and easy to reline and rebase. Six commercial brands of polymethyl meth- acrylate, namely Stellon (DPI-India), Acralyn-H (Asian Acrylate, India), Trevalon (Dentsply-England), Lucitone 199 (Dentsply/ York division), Acralyn-H (Super Unbreakable), Trevalon HI (Dentsply, Detray division, England) were tested by breaking them using Analog Pendulum (ASTM D 256).
  
  
  RESULTS
  From the entire study the maximum impact strength was reported for Acralyn-H super unbreakable (Asian Acrylates, India) 62.19 joules.
  
  
  CONCLUSIONS
  All the analysis led to conclusion that there is basic change in material composition within and among the different groups of denture base resins.
  
  
  CONCLUSIONS
  The complete dentures made using denture base resins with high impact strength valves (e.g. Acralyn-H super unbreakable) will be more durable and can be used by the patient for considerable period of time, i.e. beyond 4 to 5 years.
authors.affiliation: Professor and Head, Department of Prosthodontics, Government Dental College, RIMS, Kadapa, Andhra Pradesh, India.
authors.forename: R
authors.initials: R
authors.lastname: Narendra
authors.affiliation: Associate Professor, Department of Prosthodontics, Government Dental College, RIMS, Kadapa, Andhra Pradesh, India, e-mail: drchalam_77@yahoo.co.in.
authors.forename: N Simhachalam
authors.initials: NS
authors.lastname: Reddy
authors.affiliation: Associate Professor, Department of Prosthodontics, Government Dental College, RIMS, Kadapa, Andhra Pradesh, India.
authors.forename: Sashi Deepth
authors.initials: SD
authors.lastname: Reddy
authors.affiliation: Assistant Professor, Department of Prosthodontics, Government Dental College, RIMS, Kadapa, Andhra Pradesh, India.
authors.forename: C R Sashi
authors.initials: CR
authors.lastname: Purna
authors.affiliation: Professor and Head, Department of Conservative and Endodontics Government Dental College, RIMS, Kadapa, Andhra Pradesh, India.
authors.forename: M Chandra
authors.initials: MC
authors.lastname: Shekar
authors.affiliation: Professor and Head, Department of Oral and Maxillofacial Surgery Government Dental College, RIMS, Kadapa, Andhra Pradesh, India.
authors.forename: S
authors.initials: S
authors.lastname: Balasubramanyam
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D003819:Denture Bases; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D008768:Methylmethacrylates / Q000737:chemistry; D058105:Polymerization; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D013314:Stress, Mechanical; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D003764:Dental Materials; D008768:Methylmethacrylates; D014867:Water; C070869:stellon C; C040291:Lucitone; C029883:Trevalon universal; D019904:Polymethyl Methacrylate