title: Do resin cements influence the cuspal deflection of teeth restored with composite resin inlays?
abstract: The aim of this study was to evaluate the influence of different resin cements on the cuspal deflection of endodontically treated teeth restored with composite resin inlays. Sixty upper premolars were randomly divided into five groups (n=12): 1 - sound teeth; 2 - cavity; 3 - Rely X ARC; 4 - RelyX Unicem; 5 - SeT. The teeth from groups 2, 3, 4 and 5 received a MOD preparation and endodontic treatment. Impressions were made with vinyl polysiloxane and poured using type IV die stone in groups 3, 4 and 5. Inlays with composite resin were built over each cast and luted with the resin cements. A 200 N load was applied on the occlusal surface, and cuspal deflection was measured using a micrometer. After 24 h, cuspal deflection was measured again using a 300 N load. The Student t-test showed that there was no statistically significant difference between the 200 N and 300 N occlusal loads only for the sound teeth group (p = 0.389) and the RelyX ARC group (p = 0.188). ANOVA and Tukey'test showed that the sound teeth had the lowest mean cuspal deflection, differing statistically from the other groups (p<0.05). The highest cuspal deflections were obtained in the SeT group and the cavity group, with no statistical difference between them. Intermediate values were obtained in RelyX ARC group and RelyX Unicem group, which differed statistically. The self-adhesive resin cements RelyX Unicem and SeT showed less capacity to maintain the stiffness of the tooth/restoration complex than the conventional resin cement RelyX ARC.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Pontifical Catholic University of Rio Grande do Sul, Brazil.
authors.forename: Helen C V
authors.initials: HC
authors.lastname: da Rosa
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Pontifical Catholic University of Rio Grande do Sul, Brazil.
authors.forename: Maurem L
authors.initials: ML
authors.lastname: Marcondes
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Pontifical Catholic University of Rio Grande do Sul, Brazil.
authors.forename: Niélli C
authors.initials: NC
authors.lastname: de Souza
authors.affiliation: Department of Preventive Dentistry, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: João B B
authors.initials: JB
authors.lastname: Weber
authors.affiliation: Department of Dental Materials, School of Dentistry, Pontifical Catholic University of Rio Grande do Sul, Brazil.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Spohr
mesh_terms: D003188:Composite Resins; D003799:Dental Stress Analysis; D006801:Humans; D007284:Inlays; D008422:Materials Testing; D019279:Resin Cements; D013314:Stress, Mechanical; D019553:Tooth, Nonvital / Q000628:therapy
chemical_list: D003188:Composite Resins; D019279:Resin Cements