The influence of "C-factor" and light activation technique on polymerization contraction forces of resin composite
J. appl. oral sci
;
20(6): 603-606, Nov.-Dec. 2012. ilus, tab
Article
in English
| LILACS
| ID: lil-660629
ABSTRACT
OBJECTIVES:
This study evaluated the influence of the cavity configuration factor ("C-Factor") and light activation technique on polymerization contraction forces of a Bis-GMA-based composite resin (Charisma, Heraeus Kulzer). MATERIAL ANDMETHODS:
Three different pairs of steel moving bases were connected to a universal testing machine (emic DL 500) groups A and B - 2x2 mm (CF=0.33), groups C and D - 3x2 mm (CF=0.66), groups e and F - 6x2 mm (CF=1.5). After adjustment of the height between the pair of bases so that the resin had a volume of 12 mm³ in all groups, the material was inserted and polymerized by two differentmethods:
pulse delay (100 mW/cm² for 5 s, 40 s interval, 600 mW/cm² for 20 s) and continuous pulse (600 mW/cm² for 20 s). Each configuration was light cured with both techniques. Tensions generated during polymerization were recorded by 120 s. The values were expressed in curves (Force(N) x Time(s)) and averages compared by statistical analysis (ANOVA and Tukey's test, p<0.05).RESULTS:
For the 2x2 and 3x2 bases, with a reduced C-Factor, significant differences were found between the light curing methods. For 6x2 base, with high C-Factor, the light curing method did not influence the contraction forces of the composite resin.CONCLUSIONS:
Pulse delay technique can determine less stress on tooth/restoration interface of adhesive restorations only when a reduced C-Factor is present.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Bisphenol A-Glycidyl Methacrylate
/
Composite Resins
/
Light-Curing of Dental Adhesives
/
Curing Lights, Dental
/
Polymerization
Language:
English
Journal:
J. appl. oral sci
Journal subject:
Dentistry
Year:
2012
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
University of São Paulo/BR
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