Heat treatment following surface silanization in rebonded tribochemical silica-coated ceramic brackets: shear bond strength analysis
J. appl. oral sci
;
21(4): 335-340, Jul-Aug/2013. tab, graf
Article
in English
| LILACS
| ID: lil-684573
ABSTRACT
OBJECTIVE:
This study aimed to evaluate the effects of heat treatment on the tribochemical silica coating and silane surface conditioning and the bond strength of rebonded alumina monocrystalline brackets. MATERIAL ANDMETHODS:
Sixty alumina monocrystalline brackets were randomly divided according to adhesive base surface treatments (n=20) Gc, no treatment (control); Gt, tribochemical silica coating + silane application; Gh, as per Gt + post-heat treatment (air flux at 100ºC for 60 s). Brackets were bonded to the enamel premolars surface with a light-polymerized resin and stored in distilled water at 37ºC for 100 days. Additionally, half the specimens of each group were thermocycled (6,000 cycles between 5-55ºC) (TC). The specimens were submitted to the shear bond strength (SBS) test using a universal testing machine (1 mm/min). Failure mode was assessed using optical and scanning electron microscopy (SEM), together with the surface roughness (Ra) of the resin cement in the bracket using interference microscopy (IM). 2-way ANOVA and the Tukey test were used to compare the data (p>0.05).RESULTS:
The strategies used to treat the bracket surface had an effect on the SBS results (p=0.0), but thermocycling did not (p=0.6974). Considering the SBS results (MPa), Gh-TC and Gc showed the highest values (27.59±6.4 and 27.18±2.9) and Gt-TC showed the lowest (8.45±6.7). For the Ra parameter, ANOVA revealed that the aging method had an effect (p=0.0157) but the surface treatments did not (p=0.458). For the thermocycled and non-thermocycled groups, Ra (µm) was 0.69±0.16 and 1.12±0.52, respectively. The most frequent failure mode exhibited was mixed failure involving the enamel-resin-bracket interfaces.CONCLUSION:
Regardless of the aging method, Gh promoted similar SBS results to Gc, suggesting that rebonded ceramic brackets are ...
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Silanes
/
Ceramics
/
Dental Bonding
/
Orthodontic Brackets
/
Silicon Dioxide
Type of study:
Evaluation studies
Limits:
Humans
Language:
English
Journal:
J. appl. oral sci
Journal subject:
Dentistry
Year:
2013
Type:
Article
Similar
MEDLINE
...
LILACS
LIS