To determine the effect of slight differences in pin alignment markings on pin alignment and occlusal contacts, left and right second premolar and first molar occlusal contact areas were compared before and after the height of the incisal pin was increased. One Kavo Protar 3 articulator with an incremental type of calibrated guide pin was used for the study. Ten polyvinylsiloxane right and left posterior interocclusal records of occluded impact resistant resin casts were made at five different pin positions: 0, 50, 150, 250 and 500 Ám. The use of a computerized image analysis program provided quantitative measurements of light transmitted through the occlusal records. T-tests were used to statistically determine effects of the initial 50 Ám increase in incisal pin alignment. Data of certain areas for other pin heights were incomplete due to an unpredictable increase of material thickness beyond the measuring threshold of this study. Data was gathered from analysis of the second premolar and the first molar areas bilaterally. There were statistically significant differences from a 0 to 50 Ám raise of the incisal guide pin (P < 0.05). Statistics at other pin heights were not performed because data were incomplete due to an increase in material thickness that could not be predicted based on current literature. Precise alignment of incisal pin is required to assure occlusal precision in restorative dentistry.
Keywords: articulator, incisal guide pin, interocclusal recording material, occlusal contacts