title: Clinical adhesive sealing of the pulp chamber following endodontic treatment: influence of thermomechanical loading on microleakage.
abstract: OBJECTIVE
  To test the influence of thermomechanical loading and mode of cleaning the pulp chamber on coronal microleakage of adhesive sealings over root canal fillings.
  
  
  METHODS
  Root canals of molars were instrumented to size 60 taper .02 and filled with AH plus (Dentsply DeTrey) and a single gutta-percha cone size 55 taper .02. After removal of residual sealer with an alcoholmoistened foam pellet, different pretreatments were performed: groups 1 and 5: no further pretreatment; groups 2 and 6: use of a water cooled high-speed diamond bur; groups 3 and 7: etch-and-rinse with 37% H3PO4 for 10 s; groups 4 and 8: diamond bur and etching. Then Syntac (Ivoclar Vivadent) and two consecutive layers of Tetric flow (Ivoclar Vivadent) were applied. After placing glass-ionomer cement as a provisional restoration, teeth of groups 5 to 8 were additionally subjected to thermomechanical loading (chewing simulation of 200,000 cycles/50 N) and thermocycling (2880 cycles between 5 degrees C and 55 degrees C). A dye penetration test (methylene blue dye 5%, centrifugation for 3 min at 30 G) was used to evaluate linear dye penetration and dye penetration area. Statistical tests were performed using SPSS Win 12.0 (Kolmogorov-Smirnov test, two-way ANOVA, t-test).
  
  
  RESULTS
  Thermomechanical loading (TML) had a negative impact on coronal seal (two-way ANOVA, p < 0.001). Among TML groups, group 7 (etch-and-rinse) performed best, exhibiting the least influence of TML.
  
  
  CONCLUSIONS
  For adhesive sealing of the pulp chamber floor, the etch-and-rinse technique combined with a flowable resin composite showed promising results. Nevertheless, a stabilizing restoration should be placed as soon as possible.
authors.affiliation: Dental Clinic 1-Operative Dentistry and Periodontology, University of Erlangen-Nuremberg, Erlangen, Germany. ebert@dent.uni-erlangen.de
authors.forename: Johannes
authors.initials: J
authors.lastname: Ebert
authors.forename: Christian
authors.initials: C
authors.lastname: Löffler
authors.forename: Matthias Johannes
authors.initials: MJ
authors.lastname: Roggendorf
authors.forename: Anselm
authors.initials: A
authors.lastname: Petschelt
authors.forename: Roland
authors.initials: R
authors.lastname: Frankenberger
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D001732:Bite Force; D004396:Coloring Agents; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003754:Dental High-Speed Equipment; D003763:Dental Leakage / Q000145:classification*; D003786:Dental Pulp Cavity / Q000648:ultrastructure*; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry; D018130:Diamond / Q000737:chemistry; D004853:Epoxy Resins / Q000737:chemistry / Q000627:therapeutic use; D005899:Glass Ionomer Cements / Q000737:chemistry; D006171:Gutta-Percha / Q000737:chemistry / Q000627:therapeutic use; D006801:Humans; D008422:Materials Testing; D008751:Methylene Blue; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry / Q000627:therapeutic use*; D012389:Root Canal Obturation / Q000379:methods*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D013314:Stress, Mechanical; D013696:Temperature
chemical_list: D004396:Coloring Agents; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D004853:Epoxy Resins; D005899:Glass Ionomer Cements; D010756:Phosphoric Acids; D019279:Resin Cements; D012387:Root Canal Filling Materials; C078484:Syntac dentine adhesive; C534916:epoxy resin-based root canal sealer; C452226:tetric flow composite resin; D018130:Diamond; D006171:Gutta-Percha; C030242:phosphoric acid; D008751:Methylene Blue