Measurement of composite shrinkage using a fibre optic Bragg grating sensor

Abstract

Fibre Bragg grating is used to determine resin-based composite shrinkage. Two composite resins (Freedom from SDI and Z100 from 3M) were tested to determine the polymerization contraction behaviour. Each sample of resin was prepared with an embedded fibre Bragg grating. A LED activation unit with wavelength from 430 nm to 470 nm (Dabi Atlante) was used for resin polymerization. The wavelength position of the peak in the optical reflection spectra of the sensor was measured. The wavelength shift was related to the shrinkage deformation of the samples. Temperature and strain evolution during the curing phase of the material was monitored. The shrinkage in the longitudinal direction was 0.15 +/- 0.02% for resin Z100 (3M) and 0.06+/-0.01% for Freedom (SDI); two-thirds of shrinkage occurred after the first 50 s of illumination.

Cuspal Displacement Induced by Bulk Fill Resin Composite Polymerization: Biomechanical Evaluation Using Fiber Bragg Grating Sensors

“…However, at the beginning of the second curing light exposure, an expressive and prolonged expansion peak could be observed during all the 30-second irradiation time. These events can be interpreted as the thermal expansion effect caused either by the heat from the curing light or by the exothermic nature of the free radical polymerization of dimethacrylate monomers, as pointed out by other authors [ 4 , 19 , 20 ]. When polymerization shrinkage exceeds thermal expansion in the first expansion peak, fast overall material shrinking takes place, evidenced by a sudden increase contraction strain [ 19 , 20 ].…”

“…These events can be interpreted as the thermal expansion effect caused either by the heat from the curing light or by the exothermic nature of the free radical polymerization of dimethacrylate monomers, as pointed out by other authors [ 4 , 19 , 20 ]. When polymerization shrinkage exceeds thermal expansion in the first expansion peak, fast overall material shrinking takes place, evidenced by a sudden increase contraction strain [ 19 , 20 ]. In opposite, the persistent expansion peak observed along the second irradiation period occurs when a considerable cross-linking of the monomer has already been achieved, meaning that the thermal effect has greater relative influence on the dimensional behavior of both resin composites.…”

“…Fiber Bragg grating (FBG) sensors can be used to perform real-time local temperature and strain measurements [ 17 – 20 ]. Fiber optical sensors have the advantage of presenting immunity to electromagnetic interference [ 21 ], small dimensions [ 17 – 20 ], high resolution and sensibility, chemical inertness [ 17 – 19 ], biocompatibility [ 17 ], long-term stability [ 20 ], multiplexing capability, possibility to be embedded in different structures [ 17 , 22 ], and ability to perform remote measurements [ 21 ].…”

Redes de Bragg utilizadas para mensuração da contração de polimerização de duas resinas acrílicas na moldagem aberta de prótese sobre implantes

“…Nela os postes de moldagem são unidos, e após a polimerização inicial da resina (por volta de 15 minutos), a esplintagem é seccionada com um disco de carborundum ou ponta diamantada em alta rotação e a união é restabelecida com uma pequena porção da mesma resina acrílica. 4 Sensores de fibra ótica têm sido aplicados em estudos biomédicos em análises de materiais odontológicos, 5 como cimentos resinosos [6][7][8] e resinas acrílicas, 9 e na validação de métodos de esterilização de materiais. Os sensores caracterizam-se pela capacidade de detecção de alterações térmicas e deformações mecânicas.…”

Characterization of different water/powder ratios of dental gypsum using fiber Bragg grating sensors

“…Characterization of different water/powder ratios of dental gypsum using fiber Bragg grating sensors [9][10][11][12] . Thus, during the last few years, research work devoted to studying and exploring the potential application of fiber optic technology in biomedicine has increased significantly [13][14][15][16] .…”