Mechanical characterization and ion release of bioactive dental composites containing calcium phosphate particles.
J Mech Behav Biomed Mater
; 84: 161-167, 2018 08.
Article
em En
| MEDLINE
| ID: mdl-29783203
OBJECTIVE: to verify the effect of the addition of dicalcium phosphate dihydrate (DCPD) particles functionalized with di- or triethylene glycol dimethacrylate (DEGDMA or TEGDMA) on the degree of conversion (DC), post-gel shrinkage (PS), mechanical properties, and ion release of experimental composites. METHODS: Four composites were prepared containing a BisGMA/TEGDMA matrix and 60â¯vol% of fillers. The positive control contained only barium glass fillers, while in the other composites 15â¯vol% of the barium was replaced by DCPD. Besides the functionalized particles, non-functionalized DCPD was also tested. DC after 24â¯h (nâ¯=â¯3) was determined by FTIR spectroscopy. The strain gage method was used to obtain PS 5â¯min after photoactivation (nâ¯=â¯5). Flexural strength and modulus (nâ¯=â¯10) were calculated based on the biaxial flexural test results, after specimen storage for 24â¯h or 60 days in water. The same storage times were used for fracture toughness testing (FT, nâ¯=â¯10). Calcium and phosphate release up to 60 days was quantified by ICP-OES (nâ¯=â¯3). Data were analyzed by ANOVA/Tukey test (alpha: 5%). RESULTS: Composites containing functionalized DCPD presented higher DC than the control (pâ¯<â¯0.001). The material containing DEGDMA-functionalized particles showed higher PS than the other composites (pâ¯<â¯0.001). After 60 days, only the composite with DEGDMA-functionalized DCPD presented fracture strength similar to the control, while for flexural modulus only the composite with TEGDMA-functionalized particles was lower than the control (pâ¯<â¯0.001). FT of all composites containing DCPD was higher than the control after 60 days (pâ¯<â¯0.005). Calcium release was higher for the composite with non-functionalized DCPD at 15 days and no significant reductions were observed for composites with functionalized DCPD during the observation period (pâ¯<â¯0.001). For all the tested composites, phosphate release was higher at 15 days than in the subsequent periods, and no difference among them was recorded at 45 and 60 days (pâ¯<â¯0.001). CONCLUSIONS: DCPD functionalization affected all the studied variables. The composite with DEGDMA-functionalized particles was the only material with strength similar to the control after 60 days in water; however, it also presented the highest shrinkage. The presence of DCPD improved FT, regardless of functionalization. DCPD functionalization reduced ion release only during the first 15 days.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Resinas Sintéticas
/
Fosfatos de Cálcio
/
Fenômenos Mecânicos
Idioma:
En
Revista:
J Mech Behav Biomed Mater
Assunto da revista:
ENGENHARIA BIOMEDICA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Holanda