1. Photoelastic analysis of the influence of prosthetic material on the stress distribution in bone around implant
Sijia ZHANG ; Jianyu ZENG ; Jia LI ; Ru ZHANG ; Juanya YIN ; Hui WANG
Chinese Journal of Stomatology 2018;53(1):30-35
Objective:
To provide a reference for a suitable alternative treatment choice for implant-supported prostheses, and to explore the influence of 3 types of prosthetic material on the stress distribution around implant.
Methods:
The implant-abutment analogs were embedded individually into photoelastic resin blocks, which were medical pure titanium castings reproducing the surface and outline of implant (diameter 4.3 mm, length 11.5 mm) and esthetic abutment (regular profile, 1 mm). The prostheses were divided into 3 groups according to the type of prosthetic material. Each group consisted of 5 samples. The samples of composite resin ceramic and zirconia group were milled by chair-side computer aided design and computer aided manufacture (CAD/CAM) system. The samples of porcelain-fused-to-metal crown group were made manually and a pre-arranged silicone rubber impression of CAD/CAM crown would guide to shape the veneer porcelain. Each set was submitted to a 300 N compressive load axially or obliquely (75°). The stress value in the peri-implant bone at the level of the neck, neck1/3, middle1/3 and root1/3 of the sections (0.5, 1.5, 2.5, 3.5 mm) from implant was analyzed by digital photoelasticity, and the stress cushioning effect of 3 types of prosthetic material was comprehensively evaluated.
Results:
The time spent reaching the stress peak of composite resin ceramic group [(1.58±0.08) s, axially; (2.75±0.21) s, obliquely] was larger than that of the zirconia group [(1.40±0.12) s, axially; (2.30±0.25) s, obliquely] (