A comparative study of bulk-fill composites: degree of conversion, post-gel shrinkage and cytotoxicity
Braz. oral res. (Online)
;
32: e17, 2018. tab, graf
Article
in English
| LILACS
| ID: biblio-889495
ABSTRACT
Abstract Bulk-fill composites are claimed to be restorative materials used in deep preparations and effectively photoactivated in layers up to 4 mm. The aim of the present study was to evaluate the degree of conversion, post-gel volumetric shrinkage, and cytotoxicity of six bulk-fill and two conventional composites. Degree of conversion was determined by FTIR spectroscopy; post-gel volumetric shrinkage was determined using the strain gauge method; and cytotoxicity in human fibroblasts was evaluated indirectly by the MTT assay. Data were subjected to one-way ANOVA/Tukey's test (α = 0.05). All materials, including bulk-fill and conventional composites, were classified as non-toxic, with cell viability higher than 70%. Bulk-fill composites exhibited volumetric shrinkage similar to or lower (1.4 to 0.4%) than that of conventional composites (1.7-2.1%). However, only four of the bulk-fill composites were able to sustain a homogeneous conversion at the 4-mm depth. Despite their non-toxicity and shrinkage similar to that of conventional materials, not all commercial bulk-fill materials were able to maintain a conversion as high as 80% of the superficial layer, at the 4-mm depth, indicating some failure in the bulk-fill design of some commercial brands. Therefore, the use of bulk-fill materials in dental practice is advantageous, but special attention should be given to the selection and correct use of the materials.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Composite Resins
/
Polymerization
Limits:
Humans
Language:
English
Journal:
Braz. oral res. (Online)
Journal subject:
Dentistry
Year:
2018
Type:
Article
/
Project document
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Ibirapuera/BR
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