[Preliminary study on tactile function of implant-supported single crowns].

Objective To measure passive tactile threshold of implant-supported single crowns (ISSC) in six orthogonal orientations,to analyze impact factors,and to guide the occlusal adjustment in a personalized manner.Methods The passive tactile thresholds of 24 implant-supported single crowns (5 maxillary anterior teeth,7 maxillary posterior teeth and 12 mandibular posterior teeth) from 19 ISSC patients (8 men and 11 women,from 25 years old to 56 years old) were measured in six orthogonal orientations (four horizontal orientations of labial or buccal,lingual,mesial and distal,and two axial orientations of apical and coronal) using a digital test system for tactile function of teeth.SPSS 19.0 for windows was used to analyze impact factors,using double-sided test,with a significance level of 0.05.Paired-samples t test was used to test the difference between implant-supported single crowns and the controlled natural teeth,and between different time points.One-way ANOVA was used to test the difference between different orientations,maxilla-mandibular anterior-posterior,and men-women.Results The passive tactile thresholds of ISSC and control teeth were (1282 ± 709) and (40 ± 40) mN respectively.The difference was of statistical significance (P ＜ 0.001).The passive tactile thresholds of buccal-lingual,mesial-distal and axial of ISSC were (1334 ± 696),(1102 ± 605) and (1412 ± 791) mN respectively,of which,the difference between mesial-distal and axial was of statistical significance (P ＜ 0.05).The passive tactile thresholds of ISSC of maxillary anterior teeth,posterior teeth and mandibular posterior teeth were (1003 ± 616),(1302 ± 620) and (1386 ± 769) mN respectively,of which,the difference between maxillary anterior teeth and posterior teeth was of statistical significance (P ＜ 0.05).The passive tactile thresholds of ISSC of men and women were (1751 ±784) and (946 ± 393) mN respectively,the difference was of statistical significance (P ＜ 0.001).The passive tactile thresholds of ISSC of one-week and one-month after wearing the teeth were (1421 ± 826) and (1411 ± 814) mN respectively,the difference was of no statistical significance (P ＞ 0.05).Conclusions The passive tactile threshold of ISSC was more than 65 times as much as that of the natural teeth.There was statistical significance between different orientations,between maxillary anterior and posterior teeth,and between men and women.No statistical significance was found between maxillary and madibular posterior teeth and between one-week and one-month after wearing the teeth. Key words: Dental implants;  Touch;  Threshold limit values