Long-term reliability of semiadjustable articulator interchangeability.
OBJECTIVE
Interchangeability between articulators allows mounted casts to be accurately transferred from one articulator to another. The purpose of this study was to evaluate the interchangeability of Whip-Mix model #2240 articulators (Whip-Mix Corporation, Louisville, KY) that had been in clinical use for between 1 and 6 years.


METHODS
Forty-six Whip-Mix model #2240 articulators that had been in clinical use by students, practitioners, or laboratory technicians for between 1 and 6 years were evaluated for interchangeability using the Whip-Mix #2245 check system. The horizontal tolerance of the check system was 94 microns. The articulators were also evaluated in the vertical dimension at four locations around the check system cylinders using 26-micron shimstock. Vertical discrepancies between the cylinders were recorded as the thickness of 0, 1, 2, or more than 2 pieces of shimstock.


RESULTS
Thirty-eight of the articulators (83%) passed the test for interchangeability. These articulators were interchangeable with other Whip-Mix model #2240 articulators fabricated over a 5 1/2-year period (December 1990 to August 1996). In the vertical dimension, most articulators had discrepancies < or = 26 microns. Three articulators (6.5%) had vertical discrepancies greater than 52 microns.


CONCLUSIONS
(1) Eighty-three percent of Whip-Mix model #2240 articulators that had been in clinical use for between 1 and 6 years remained interchangeable within a tolerance of 94 microns in the horizontal dimension. (2) Only three articulators in this study (6.5%) had a vertical discrepancy at any location between the cylinders greater than 52 microns. (3) The model #2240 articulator has the potential to remain interchangeable during clinical use.
Price
R B
RB
Department of Dental Clinical Sciences, Faculty of Dentistry, Dalhousie University, Halifax, Canada. rbprice@is.dal.ca
Mansfield
W M
WM
D003725:Dental Articulators; D004867:Equipment Design; D015203:Reproducibility of Results