title: Flexural strength and hardness of resins for interim fixed partial dentures.
abstract: BACKGROUND
  Materials used for the fabrication of interim restorations must satisfy biological, esthetic, and functional needs. Strength and wear resistance are two important physical properties contributing to clinical efficiency.
  
  
  OBJECTIVE
  The objective of this in vitro study was to evaluate and compare the flexural strength and hardness of five resins used for the fabrication of interim fixed partial dentures.
  
  
  METHODS
  Five groups containing ten specimens of each material were fabricated in customized brass split molds with dimensions 65 × 10 × 2.5 mm. The materials subjected to this study were Revotek LC (group RLC), Protemp II (group PSC), Acry-lux V with regular monomer (group AHC), Acry-lux V with self-cure monomer (group ASC), DPI self-cure tooth molding powder (group DSC). The specimens were polymerized according to the manufacturers' instructions and were evaluated for flexural strength using a universal testing machine and for hardness using a microhardness tester.
  
  
  METHODS
  The mean of the five groups was compared using one way analysis of variance (ANOVA) and pair-wise comparison was done using Tukeys honesty significance difference (HSD) test. P ≤.05 was considered to be statistically significant.
  
  
  RESULTS
  Flexural test results showed that group AHC (79.8950 MPa) had the highest flexural strength followed, in descending order, by group PSC (77.9700 MPa), group ASC (63.7150 MPa), group RLC (58.8110 MPa), and group DSC (51.9840 MPa). Statistically, the difference was found to be highly significant among all the groups. The hardness tests showed that group AHC (17.6900 KHN) had the highest hardness value followed, in descending order, by group PSC (15.9400 KHN), group RLC (12.6000 KHN), group ASC (11.2500 KHN), and group DSC (8.7700 KHN). Statistically, the difference was found to be highly significant among all the groups.
  
  
  CONCLUSIONS
  Group AHC, representing a heat-polymerizing resin, showed the highest flexural strength and hardness values as compared to auto-polymerizing resins and light-polymerizing resin.
authors.affiliation: Department of Prosthodontics, KMCT Dental College, Kozhikode, Kerala, India. drliju_jo@yahoo.com
authors.forename: Liju Jacob
authors.initials: LJ
authors.lastname: Jo
authors.forename: Kamalakanth K
authors.initials: KK
authors.lastname: Shenoy
authors.forename: Sanath
authors.initials: S
authors.lastname: Shetty
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D003799:Dental Stress Analysis; D003819:Denture Bases; D003779:Denture Design; D003830:Denture, Partial, Fixed; D003833:Denture, Partial, Temporary; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D018583:Pliability; D019904:Polymethyl Methacrylate / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D003188:Composite Resins; C505099:Revotec LC; C561675:acry-lux V; D019904:Polymethyl Methacrylate; C069714:Protemp