OBJECTIVETo discuss the influence of reducing buccolingual width of artificial crown on distribution of biting force and masticatory efficiency in unilateral distal-extension implant denture and provide valuable information for the design of buccolingual width. To find a design that the biting force of implant prothesis was less evident than those on the contralateral natural teeth without compromising masticatory efficiency.

METHODST-Scan II occlusal analyzer and 722 grating spectrophotometer were used to analyze the distribution of biting force and masticatory efficiency in unilateral distal-extension implant denture. Heat-cured resin crowns with three different buccolingual width (group A: standard buccolingual width; group B: the buccolingual width was reduced by 1/4; group C: the buccolingual width was reduced by 1/3) were designed as follow, one was contoured with standard buccolingual width, the other two were made with reducd buccolingual width by 1/4 and 1/3.

RESULTSThe ratio of biting force (ROF) of group C was 16.25%, which was significantly lower than group A (27.38%) and B (22.60%) (P < 0.0083). The X axis displacement of center of occlusal force (COF) of group C was 2.0 mm, which was significantly difference with group A (1.5 mm, P = 0.004). The masticatory efficiency absorbance A value (MEA) of group C was 0.217, which was significantly lower than group A (0.345, P = 0.005) and B (0.289, P = 0.004).

CONCLUSIONSAccording to the study, the buccolingual width of the crown reduced by 1/4 was a more ideal design for unilateral distal-extension implant denture.