Abstract: Objective The aim of this study was to modify the custom impression technique for soft tissue around a dental implant, to compare the clinical working time and material consumption for fabricating custom impression coping with conventional and modified methods, and to evaluate the clinical applicability of the modified method. Methods From October to December 2020, 20 implant-supported interim restorations of the maxillary anterior teeth were collected in the Department of Prosthodontics, Peking University School and Hospital of Stomatology. The conventional and modified methods were used to fabricate custom impression coping by self-controlled trial. Within the conventional method, a silicone matrix was used to capture the emergence profile of the interim restoration, thereafter a custom impression coping was made accordingly. In the modified method, a prefabricated reusable resin base embedding an implant analog was made. The base and a flowable silicone were used to register the soft-tissue transition zone created by the interim restoration. Finally, the tissue contour was transferred to the impression post. The working time and material consumption of the two methods were recorded and compared. Results In terms of clinical time, the average time of fabricating the index by the modified method was (323.6±20.3)s, which was significantly lower than that of the conventional method (482.8±43.5)s The average time of making impression coping with the conventional and modified methods were (213.4±10.9) s and (215.6±9.8) s, respectively. There was no significant difference between the two groups (P>0.05). In terms of the material consumption, the improved method does not require the use of self-cure resin, while the average weight of the self-cure resin of the conventional methods were (427.5±72.2) mg. There was significant difference between the two groups (P< 0.05). Regarding the consumption of the silicone matrix, the modified method was (524.5±29.1) mg, which was significantly lower than that of the conventional method (14473.1±732.6)mg. The difference between the two methods was significant. The average weight of pattern resin of the conventional and modified methods were (80.0±13.4) mg and (82.0±17.4) mg, respectively. The difference between the two groups was not significant (P>0.05). Conclusions The clinical working time and material consumption spent on fabricating the custom impression coping by the modified method were less than those of the conventional method. Therefore, the modified method of custom impression for soft tissue may save chairside time and materials. It is worthy of clinical application..

Key words: Dental implant, Esthetic, Emergence profile, Impression