Evaluation of occlusal contacts in the dental laboratory: influence of strip thickness and operator experience.

PURPOSE: The purpose of this study was to evaluate the influence of recording strip thickness and of operator-dependent factors on the assessment of contact area on a cast mounted on an articulator. MATERIALS AND METHODS: Thirteen dental students and 13 experts (dentists and dental technicians) performed occlusal maneuvers on casts mounted on an articulator, using recording strips of 8- and 40-micron thickness. Contact area, force, and time of biting relative to each group of operators using each type of paper were compared. RESULTS: Both groups obtained significantly greater contact areas with the thicker strip. Students applied significantly stronger but shorter bitings than experts, but obtained smaller contact areas, particularly with the thinner strip. In operators, the extension of contact markings using the 8-micron strip was closely related to the biting time but not to the occlusion force, while neither time nor force of biting had a significant influence when using the 40-micron strip. CONCLUSION: The assessment of occlusal contact in the dental laboratory was significantly influenced by paper thickness, operator experience, biting force, and time. The 40-micron strip was less influenced by operator experience, strength, and duration of biting.