ความถูกต้องและความแม่นยำของการใช้ขี้ผึ้งบันทึกการสบยื่นในการตั้งค่าความเอียงแนวนำคอนดายล์: การศึกษานอกร่างกาย

Abstract

Using a semi-adjustable articulator in fabricating dentures requires setting up of condylar inclinations in the device to simulate the movement paths of condyles in each patient. This study aimed to evaluate the accuracy and reliability of using a protrusive wax record technique in setting up the condylar inclinations. Materials and Methods: One volunteer was chosen to take an impression and facebow for two sets of models before installing them into the articulator. Thirty dentists that fulfilled the requirements were included in this study. The participants filled out questionnaire about their experience in setting up condylar inclination. Part 1: The condylar inclinations of a semi-adjustable articulator with mounted fully dentate models were set and obscured from all participants, after which each participant was asked to make a protrusive wax record. Then, the condylar inclinations were changed by the researcher. Subsequently, each participant was asked to reset the condylar inclinations by utilizing his/her wax record. The time each participant spent on making a wax record and condylar inclination set up was recorded.Part 2: Thirtysets of protrusive wax records were prepared by the researcher, each composed of 3 different condylar inclination slopes. Then, each participant was asked to set the condylar inclinations by utilizing a randomly assigned set of records. The researcher read condylar inclination value and recorded. The error was calculated using the obtained value, then being adjusted to the absolute value. The obtained value and absolute errorvalue were then statistically analyzed. Results: There were no differences between the researcher’s preset and participants’ reset condylar inclinations (p<0.05). The mean errors in condylar inclination setting by using protrusive wax records were within an acceptablerange (<7 degrees). The setting accuracy was higher in condyle inclination with lower slope (p<0.05). There were no correlation between condylar inclination setting experience and accuracy of setting up condylar inclination. However, if the participantshadexperience more than 10 times, the errors tendedto be less than 10 degrees. The more time spent in recording and setting up condylar inclination, the fewer errors occurred. When the condylar inclination values obtained from all participants were compared, inter-rater reliability analysis revealed good agreement for the left condyle but poor agreement for the right condyle. Intra-rater reliability analysis showed good agreement of the condylar inclination value when an individual participant repeated the condylar inclination set up using the same wax record. Conclusion: The errors in condylar inclination setting by using protrusive wax records were within an acceptable range (<7 degrees). The setting accuracy was higher in condylar inclination with lower slope. When the condylar inclination values obtained from all participants were analyzed, the agreement was found to be good for the left condyle but poor for the right condyle. However, an individual participant had good agreement of the condylar inclination values when setting from the same wax record.