Evaluation of the Survey Line Validity and Satisfaction When Using the Intraoral Surveyor Model II on the Customized Model

Abstract

     The purpose of this study was to compare the validity of the survey lines on the customized model between the intraoral surveyor model II and the Ney surveyor and satisfaction when using the intraoral surveyor model II on the customized model. Twelve examiners were the first to third year postgraduate students.  The result would be considered about (1) evaluation of validity of the survey line by using the Ney surveyor and the intraoral surveyor model II and (2) the satisfaction questionnaire about the use of the intraoral surveyor model II. The difference between the distances of the two survey lines in each customized tooth was measured at the midpoint of two survey lines which was the intersected area between the lines and groove by using the stereo microscope with X30 magnification. Four customized models with four customized teeth, which were the measuring teeth, included upper right first premolar (14), upper right second molar (17), upper left second molar (27), and upper left canine (23), were sandblasted with aluminium oxide (Al₂O₃) to create the surface roughness. Then groove was created at midbuccal surface of upper left canine, proximal surface of upper right first premolar, upper right second molar and upper left second molar. Two color pencil leads including black and red colors, were used between two types of surveyor.

     The results showed that most of examiners had mean difference between the distances of two survey lines higher than the control group (0.045 ± 0.026 millimeters). The two one-sided test (TOST) at the acceptance criterion was 0.026. The confidence interval of four examiners, was about 33.3%, contained completely in the equivalence interval. That meant four examiners had validity of the survey line of the intraoral surveyor model II. The results of the satisfaction questionnaire represented that almost examiners satisfied both of use and design of the intraoral surveyor model II in high level. Suggestion in part of use, as surveying in the posterior teeth, was at moderate level. And suggestion in part of design, was height of the surveying rod, was at moderate level. It can be concluded that the intraoral surveyor model II can be used to evaluate guiding plane or path of placement and removal of the prosthesis and transferred to the patient’s mouth if it develops following the suggestions. Moreover, the examiner should be familiar with the device when using.