Impact of arbitrary and mean transfer of dental casts to the articulator on centric occlusal errors
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Thomas R. Morneburg & Peter A. Prِschel
- چاپ و سال / کشور: 2010
Description
When fabricating dental restorations, casts are usually transferred to the articulator based on arbitrary hinge axes or mean values instead of true hinge axis points. Using arbitrary hinge axis points or mean values can lead to occlusal errors if the vertical relation is changed in the articulator (e.g., when a centric record is used). This study predicted the probability of occlusal errors occurring in a group of subjects when casts are mounted based on arbitrary hinge axis points or mean values. In 57 healthy volunteers, true hinge axis points, arbitrary hinge axis points, right infraorbital point, maxillary incisal point, and the palatal cusps of the second molars were determined. Mean hinge axis points were established based on Balkwill angles between 17پ‹ and 25پ‹. Occlusal errors evoked by cast mounting in relation to arbitrary or mean axes compared to true hinge axes were calculated. Errors were determined for vertical relation settings of 2 and 4 mm. With 2 mm vertical relation, occlusal errors .340 ƒتm occurred with a 10% probability with arbitrary hinge axis mounting. At the same probability level, the error increased moderately to .440 ƒتm with mean value mounting and a Balkwill angle of 17پ‹. With a Balkwill angle of 25پ‹ occlusal errors .1,120 ƒتm occurred with 10% probability. Occlusal errors increased considerably with a vertical relation setting of 4 mm. If vertical relation shall be altered, a transfer of the casts according to arbitrary hinge axes is recommended. If casts are transferred according to mean values, errors are bigger depending on the articulator used
Clin Oral Invest (2011) 15:427–434 DOI 10.1007/s00784-010-0395-9 Received: 16 July 2009 / Accepted: 16 February 2010 / Published online: 25 March 2010
