Clinical applicational comparison of digital impression and silicon rubber impression technique in posterior implant-supported single crown restoration

Abstract

Objective: To investigate the clinical effect and satisfaction of partially edentulous patients restored with posterior implant-supported single crown by digital impression technique and traditional silicon rubber impression, in order to provide clinical reference. Methods: Sixty-four partially edentulous patients who visited the Department of Prosthodontics, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University between March 2018 and January 2021 were enrolled. There were 31 male and 33 female, and the age of the group of patients was (49.3±13.3) years. The 113 implants placed in this group of patients were divided into digital impression group (n=70) and silicone rubber impression group (n=43) according to different impression techniques, and were restored with screw-retained full zirconia single crown, and the patients were followed up for 3-36 months after treatment. The implant survival rate, upper prosthesis, peri-implant soft tissue status, marginal bone loss and patients satisfaction were recorded to evaluate the clinical effects of two impression techniques in posterior implant-supported single crown. Results: In sixty-four patients, digital impression accounted for 62% (40/64), and silicon rubber impression accounted for 38% (24/64), the survival rate of 113 implants was 100% (113/113). The prevalence of interproximal contact loss, food impaction and mechanical complication of the upper full zirconia single crown restorations were 22.7% (41/181), 8.0% (9/113) and 2.7% (3/113) separately. All the mechanical complications were abutment screw loosening. All patients maintained good oral hygiene status, the incidences of peri-implantitis and peri-implant mucositis were 0.9% (1/113) and 4.4% (5/113) respectively. The marginal bone loss was (0.24±0.11) mm. The median of satisfaction visual analogue scale score in patients was 9-10, but no statistically significant differences of all the above results were observed between the two impression techniques (P>0.05). Conclusions: The clinical effect of partially edentulous patients restored with posterior implant-supported single crown using two different impression techniques is good and the satisfaction of patients is high, but the long-term clinical effect remains to be further observed.