RESUMEN
OBJECTIVE@#This study aims to evaluate the reliability of the software Picpick in the measurement of the cusp inclination angle of a digital model.@*METHODS@#Twenty-one trimmed models were used as experimental objects. The chairside digital impression was then used for the acquisition of 3D digital models, and the software Picpick was employed for the measurement of the cusp inclination of these models. The measurements were repeated three times, and the results were compared with a gold standard, which was a manually measured experimental model cusp angle. The intraclass correlation coefficient (ICC) was calculated.@*RESULTS@#The paired t test value of the two measurement methods was 0.91. The ICCs between the two measurement methods and three repeated measurements were greater than 0.9. The digital model achieved a smaller coefficient of variation (9.9%).@*CONCLUSIONS@#The software Picpick is reliable in measuring the cusp inclination of a digital model.
Asunto(s)
Modelos Dentales , Reproducibilidad de los Resultados , Programas InformáticosRESUMEN
Objective:To survey the continuous change features of cusp angle in anatomic artificial teeth,and to investigate their effects on occlusal balance.Methods:28 artificial teeth of a complete denture were measured by optical three-dimensional(3D)scan-ner and the corresponding digital models were constructed using the reverse engineering software Surfacer 1 0.5.The working side cusp slopes of lateroprotrusive movement including the maxillary buccal cusp distal slopes and the mandibular buccal cusp mesial slopes were studied.The straight lines from bottom to top of cusp were constructed and the corresponding projected curves in occlusal surface were generated.The angulation values of straight line and the continuous change values of projected curve were calculated.Results:The angulation values of artificial teeth cusp inclination including straight line and corresponding projected curve were obtained.The maxillary working cusp inclination varied from 1 3.7°to 25.6°,and the mandibular working cusp inclination varied from 1 1 .3°to 37.7°.Conclusion:The relatively large differences of the cusp inclination among traditional anatomic artificial teeth and the convex form of the cusp are disadvantage factors to set up stable centric stop and unhindered chew course.
RESUMEN
Objective:To study the influence of cusp inclination of artificial posterior teeth on abutment displacement of unilateral distal-extension telescope crown denture.Methods:Study models of mandibular unilateral distal-extension and telescope crown dentures with the cusp inclination of 0?,12?,25? and 33? were respectively prepared. When food chip was masticated on the occlusal surface and the dentures were loaded by 29.4 N, 49 N or 68.6 N, the abutment displacement was measured.Then the data were calculated and reciprocally compared with statistical analyses. Results:Between anatomic and 25? semi-anatomic artificial posterior teeth, there were significant differences in the buccolingual and vertical abutment movement(P0.05). The parallel, inclination, twist-like and vertical movement of abutment increased with the increase of the load on the denture. The difference among different level of load was statistically significant (P