title: Improved quality of root fillings provided by general dental practitioners educated in nickel-titanium rotary instrumentation.
abstract: OBJECTIVE
  To test the hypothesis that an increased utilization of nickel-titanium rotary instrumentation (NTRI) by general dental practitioners will lead to an increased frequency of good quality root fillings. A second aim was to determine whether the educational format would exert influence on the quality.
  
  
  METHODS
  Dentists were assigned at random to three intervention groups: a 4-h lecture (L-group, n = 40); a 4-h lecture plus a full day hands-on course (LH-group, n = 40); or a control group receiving no instruction (n = 68). The control group received education later on in the study. Radiographs of two root filled molar teeth per dentist were selected at random before the start of the education program and after a 6-month clinical learning period. Using length, seal and shape of root-fillings a 5-level variable was created.
  
  
  RESULTS
  The rate of good quality root fillings increased after the introduction of NTRI. Calculated over all types of roots the frequency of excellent (score 1) root fillings increased from 31% to 51% (P = 0.006) in the L-group and from 27% to 47% (P = 0.016) in the LH-group. The frequency of low quality root-fillings (score 5) dropped in the L-group from 22% to 16% (P = 0.29) and in the LH-group from 13% to 9% (P = 0.48). No statistically significant difference was seen among the controls.
  
  
  CONCLUSIONS
  When NTRI technology replaced manual stainless steel techniques the rate of good quality root fillings increased. A significant drop in the rate of low quality root fillings was not found.
authors.affiliation: Public Dental Service, Gothenburg, Sweden. a.molander@odontologi.gu.se
authors.forename: A
authors.initials: A
authors.lastname: Molander
authors.forename: D
authors.initials: D
authors.lastname: Caplan
authors.forename: G
authors.initials: G
authors.lastname: Bergenholtz
authors.forename: C
authors.initials: C
authors.lastname: Reit
mesh_terms: D003722:Dental Alloys; D003762:Dental Instruments; D004497:Education, Dental / Q000379:methods*; D004708:Endodontics / Q000193:education*; D005792:General Practice, Dental / Q000193:education; D006801:Humans; D009532:Nickel; D011787:Quality of Health Care; D012389:Root Canal Obturation / Q000592:standards*; D018915:Root Canal Preparation / Q000295:instrumentation*; D014025:Titanium
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium