title: An 18-month longitudinal study on a new silicon-based sealer, RSA RoekoSeal: a leakage study in vitro.
abstract: OBJECTIVE
  Because leakage along root fillings may increase or decrease during the long period after filling, the accumulated leakage data measured repeatedly after filling are clinically more relevant than the data measured just once shortly after filling. The aim of this study was to determine the long-term sealing ability of a recently developed root canal sealer RSA RoekoSeal (Roeko Dental Products, Langenau, Germany).
  
  
  METHODS
  Eighty extracted human mandibular premolars were equally divided into 4 groups (n = 20) and root canal instrumented. Canals in group 1 were obturated with laterally compacted gutta-percha points and RSA, in groups 2 to 4 with vertically compacted warm gutta-percha using RSA in group 2, Pulp Canal Sealer (Kerr, Romulus, Mich) in group 3, and no sealer in group 4. With the use of a fluid transport model, leakage along entire root fillings was measured before post space preparation. After post space preparation, leakage along the remaining apical root fillings was measured repeatedly at 1 week, 1, 2, 6, 12, and 18 months respectively and recorded in microliters per day.
  
  
  RESULTS
  Before post space preparation, groups 1 and 2 leaked significantly less than groups 3 and 4 (P = .001), whereas no significant difference existed between the groups 1 and 2 (P = .317) or between the groups 3 and 4 (P = .074). For each group, a summation of the leakage at all time intervals after the post space preparation showed that the 2 RSA groups leaked significantly less than the other 2 groups (P =.000). However, no significant difference existed between the 2 RSA groups (P = .993) and between the groups 3 and 4 (P = .149).
  
  
  CONCLUSIONS
  RSA used in combination with either cold laterally compacted or warm vertically compacted gutta-percha provided a consistent seal during a period of 18 months.
authors.affiliation: Department of Cariology Endodontology Pedodontology, Academic Centre for Dentistry Amsterdam, The Netherlands. m.wu@acta.nl
authors.forename: Min-Kai
authors.initials: MK
authors.lastname: Wu
authors.forename: Emilios
authors.initials: E
authors.lastname: Tigos
authors.forename: Paul R
authors.initials: PR
authors.lastname: Wesselink
mesh_terms: D001641:Bicuspid; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D003763:Dental Leakage / Q000145:classification*; D005500:Follow-Up Studies; D006171:Gutta-Percha / Q000627:therapeutic use; D006358:Hot Temperature; D006801:Humans; D006813:Humidity; D008137:Longitudinal Studies; D008422:Materials Testing; D011176:Post and Core Technique; D012387:Root Canal Filling Materials / Q000737:chemistry*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D012825:Silicon / Q000737:chemistry; D018709:Statistics, Nonparametric; D013696:Temperature; D019227:Tooth Apex / Q000473:pathology; D015035:Zinc Oxide-Eugenol Cement / Q000627:therapeutic use
chemical_list: D003738:Dental Cements; D012387:Root Canal Filling Materials; D015035:Zinc Oxide-Eugenol Cement; C465381:roeko seal; C076543:Kerr Pulp Canal Sealer; D006171:Gutta-Percha; D012825:Silicon