title: Fracture resistance of Class II glass-ionomer cement restorations.
abstract: OBJECTIVE
  To investigate in vitro the effect of retentive grooves, GIC type and insertion method on the fracture resistance of Class II glass-ionomer cement (GIC) restorations.
  
  
  METHODS
  Premolars were divided into 12 groups (n = 10) according to three variables: retentive grooves [presence (PR) or absence AR)], GICs type [Ketac-Molar (KM), Fuji VIII (F8) and RelyX Luting (RX)], and insertion method [syringe injector (SI) or spoon excavator (SE)]. The specimens were subjected to fracture resistance test. Data were submitted to three-way ANOVA and multiple comparisons were performed using a Tukey test (P < 0.05).
  
  
  RESULTS
  Mean fracture resistance values (Kgf) +/- standard deviations (SD) were: KM (PR+SI) = 65.66 +/- 2.5; KM (PR+SE) = 62.58 +/- 2.1; KM (AR+SI) = 57.11 +/- 1.9; KM (AR+SE) = 51.94 +/- 2.3; F8 (PR+SI) = 63.05 +/- 2.1; F8 (PR+SE) = 60.12 +/- 2.3; F8 (AR+SI) = 55.11 +/- 1.9; F8(AR+SE) = 49.20 +/- 1.6; RX (PR+SI) = 50.99 +/- 2.4; RX (PR+SE) = 48.81 +/- 2.5; RX (AR+SI) = 45.53 +/- 2.6; RX (AR+SE) = 41.88 +/- 3.0. Statistically significant differences were observed among all the groups tested (P = 0.001). There was significant difference when pooled means for GIC type were compared with retentive grooves (P = 0.01) and when pooled means for retentive grooves were compared with insertion method (P = 0.01).
authors.affiliation: Department of Operative Dentistry, University of North of Paraná, Brazil.
authors.forename: Terezinha Jesus
authors.initials: TJ
authors.lastname: Esteves Barata
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bresciani
authors.forename: Ticiane
authors.initials: T
authors.lastname: Cestari Fagundes
authors.forename: Daniela Francisca
authors.initials: DF
authors.lastname: Gigo Cefaly
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Pereira Lauris
authors.forename: Maria Fidela
authors.initials: MF
authors.lastname: Lima Navarro
mesh_terms: D001641:Bicuspid; D003188:Composite Resins / Q000737:chemistry; D003737:Dental Cavity Preparation / Q000145:classification; D017268:Dental Prosthesis Retention; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000145:classification* / Q000295:instrumentation; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D003188:Composite Resins; C530340:Fuji VIII; D005899:Glass Ionomer Cements; C084550:Vitremer; C110712:ketac-molar