title: In vitro splint rigidity evaluation--comparison of a dynamic and a static measuring method.
abstract: OBJECTIVE
  The aim of this in vitro study was to investigate a dynamic and static tooth mobility assessment method in terms of reproducibility and correlation.
  
  
  METHODS
  A custom-made artificial model was used. The central incisors simulated 'injured' teeth with increased mobility, and the lateral incisors served as 'uninjured' teeth with physiological mobility. To assess tooth mobility, three consecutively repeated measurements were taken, in the vertical and horizontal dimensions before and after splinting, using the Periotest method as well as the Zwick universal testing machine. Reproducibility of the measurements was tested using anova and the Bonferroni post hoc test (α = 0.05). Correlation was analysed using Spearman's rank correlation (α = 0.05).
  
  
  RESULTS
  No significant differences were found when comparing the three consecutively taken Periotest values and the vertical Zwick values (P > 0.05). In the horizontal dimension, the first Zwick values differed from the second and third values (P < 0.05). Only a few random correlations (P < 0.05) were found when comparing the two assessment methods. Horizontal and vertical measurements within one method did not correlate (P > 0.05).
  
  
  CONCLUSIONS
  The Periotest and vertical Zwick values are highly reproducible. The measurements of the two methods do not correlate; therefore, a conversion of Periotest values into metric displacement data is not feasible. The two methods provide different valuable information about tooth mobility. The Periotest method describes the damping characteristics of the periodontal ligament while the Zwick method reveals quantitative metric values.
authors.affiliation: Dental Clinic 1 - Operative Dentistry and Periodontology, Friedrich-Alexander-University, Erlangen, Germany. berthold@dent.uni-erlangen.de
authors.forename: Christine
authors.initials: C
authors.lastname: Berthold
authors.forename: Friedrich Johannes
authors.initials: FJ
authors.lastname: Auer
authors.forename: Sergej
authors.initials: S
authors.lastname: Potapov
authors.forename: Anselm
authors.initials: A
authors.lastname: Petschelt
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry; D003799:Dental Stress Analysis / Q000295:instrumentation; D055119:Elastic Modulus; D004867:Equipment Design; D007180:Incisor / Q000293:injuries / Q000503:physiopathology; D008953:Models, Anatomic; D009969:Orthodontic Wires; D010513:Periodontal Ligament / Q000293:injuries / Q000503:physiopathology; D010517:Periodontics / Q000295:instrumentation; D015203:Reproducibility of Results; D013165:Splints; D013314:Stress, Mechanical; D014084:Tooth Avulsion / Q000503:physiopathology; D014086:Tooth Mobility / Q000503:physiopathology
chemical_list: D003188:Composite Resins; D003764:Dental Materials