VoxLim

HA008
Effectiveness of differents methods for cleaning arch wire
Araujo MTS, Canongia ACP, Lima CJ, Figueiredo LM, Puetter UT*,
Sant´Anna EF
Odontopediatria e Ortodontia - UNIVERSIDADE FEDERAL DO RIO DE JANEIRO.
E-mail: monicatirre@uol.com.br
Cleaning orthodontic archwires before reinsert in patients is necessary to reduce bacterial and
fungus biofilm. The aim of this study was to evaluate the best method of removing bacterial
and fungus biofilm. Methods: rectangular NiTi and SS wires segments from 3M and Morelli
and TMA wires from Morelli were separately divided into five groups. The wire segments were
contaminated with strains of S. mutans and C. albicas, with the exception of 4 segments of
each group that served as control. The groups were tested using six biofilm removal techniques:
friction of cotton roll with sodium hypochlorite 1% (RH); friction of cotton roll with 2%
chlorhexidine gluconate (RC); friction of cotton roll with 70% alcohol (RA); immersion in
enzymatic detergent (ID); friction of steel wool (SW) and friction of cotton roll without
chemical agents (R0). The wires were then placed in broth separately, and after an incubation
period, the optical density (OD) was measured to observe whether there was microbial growth.
The wire segments of each group were scanned with Electron Microscope (SEM) for qualitative
and quantitative analysis of treatment response. The data were submitted to one-way ANOVA
test and Tukey post-test. Results: 2% chlorhexidine and 1% sodium hypochlorite removed the
microorganisms completely while the other agents left a high microbial concentration.
HA009 Prospective longitudinal study of the dentoskeletal changes from the
use of the twin-force in the treatment of Class II malocclusion
Guimaraes‐Junior CH*, Henriques JFC, Janson G, Giampietro‐Brandão A,
Henriques RP, Almeida MR, Vedovello‐Filho M
Ortodontia - FACULDADES DA FUNDAÇÃO HERMÍNIO OMETTO.
E-mail: ibepo@terra.com.br
The objective of this study was to evaluate the dentoskeletal changes resulting from the
treatment of Class II malocclusion with a fixed functional appliance, associated with fixed
orthodontic appliance, by means of cephalometric analysis of the 86 lateral X-rays from the
43 subjects of both genders divided in two groups: Experimental Group (Group 1), with 23
patients at a mean initial age of 11.81 years, treated with the fixed functional appliance Twin
Force, for a mean period of 2.49 years and Control Group (Group 2), with 40 lateral X-
rays from 20 patients at a mean initial age of 12.54 years, presenting Class II malocclusion,
observed by a mean period of 2.19 years. It was evaluated the lateral cephalograms before
and after orthodontic treatment in the Group 1 and in the beginning and at the end of the
observation period in the Group 2. Initial and final dentoskeletal cephalometric variables and
changes with treatment were compared between the groups with t-test. The experimental
group presented a greater restriction of growth and anterior displacement of the maxilla
and a greater mandibular retrusion, because there was change in the occlusal plane and
anterior facial height. The Group 1 showed a significant improvement of maxillomandibular
relationship and the mandibular incisors, presented greater buccal inclination.
There were no statistically significant differences in the craniofacial growth pattern between the
groups; the Class II correction occurred almost entirely by dentoalveolar changes then skeletal.
HA010 Free radical concentration analysis via electron paramagnetic
resonance (EPR) for composite resin
Salomão FM*, Peron RAF, Poletto D, Borges HOI, Garbelini CCD,
Vicentin BLS, Di‐Mauro E, Hoeppner MG
Odontologia Restauradora - UNIVERSIDADE ESTADUAL PAULISTA - ARAÇATUBA.
E-mail: salomaofm@me.com
Translucent fiberglass post (FP) capacity to transmit light is a questionable property until
today. Free radical concentration (FRC) formed in a nanoparticulated composite resin (CR),
photopolymerized throughout a FP sectioned in different lengths was investigated using
Electron Paramagnetic Resonance (EPR). 15 CR samples were confectioned, divided in 5
groups (n=3), accordingly to FP length: Positive Control Group (+CG) - Polymerization device,
with 1200mW/cm2 potency, positioned directly over the samples; Negative Control Group
(-CG) - samples were not photopolymerized; Group 1 (G1) - 4mm FRC maintained the
LED 4mm away from the samples, during irradiation for photopolymerization; Group 2
(G2) - 6mm FP maintained the LED 6mm away from the samples, during irradiation for
photopolymerization; Group 3 (G3) - 8mm FP maintained the LED 8mm away from the
samples, during irradiation for photopolymerization. Samples were evaluated immediately
after photopolymerization. EPR Spectra analysis indicated that GC- was the only one not
present in the spectrum visible sign. GC+ presented the greater spectra intensity, that is, greater
FRC. G1 and G2 had similar FRC and that was greater than G3.
FRC declined from the use of FP and with the increasing distance from the LED tip and the
samples.
HA011 Influence of nanoparticle addition on the mechanical properties of
facial silicone subjected to accelerated aging
Nobrega AS*, Andreotti AM, Silva EVF, Sônego MV, Moreno A, Turcio KHL,
Sinhoreti MAC, Goiato MC
Materiais Odontológicos e Prótese - UNIVERSIDADE ESTADUAL PAULISTA - ARAÇATUBA.
E-mail: dha_sn@hotmail.com
The aim of this study was to evaluate the influence of nanoparticles addition in hardness, tear
strength and permanent deformation of Facial Silicone Silastic MDX4-4210. A total of 560
samples of Silastic were made, 280 for tear strength test, 140 for hardness test and 140 for
permanent deformation test. Nanoparticles added in the preparation of silicone samples were
zinc oxide, barium sulfate and titanium dioxide. For each test (except the tear strength test,
in which the samples are duplicated), 40 samples of silicone were made, with the addition of
each type of nanoparticles, totaling 120 samples, 10 samples of silicone with oil paint without
nanoparticles, and 10 samples only of silicone. For each type of nanoparticle added to the
facial silicone, 20 samples were prepared at a concentration of 1%, and 20 at a concentration
of 2%. For each concentration of nanoparticles oil paint was added in half of the samples
(10 samples). Samples were submitted to the tests before and after 1008 hours of accelerated
aging. Data were subjected to statistical analysis using nested ANOVA and Tukey tests. It can
be verified through the results that nanoparticles influenced the hardness, tear strength and
permanent deformation of the assessed groups
It is concluded that all evaluated nanoparticles influenced the hardness, tear strength and
permanent deformation, however the groups with addition of titanium dioxide nanoparticles
exhibited different hardness values of the clinically acceptable range. Accelerated aging
influenced all evaluated properties, regardless the addition of nanoparticles or oil paint (Apoio:
FAPESP - 2012/05270-3)
HA012
Influence of chlorhexidine on bond strength of self-etching adhesives
Andrade CO*, Salvio LA, Goes MF, Resende FO
Ore - UNIVERSIDADE FEDERAL DE JUIZ DE FORA.
E-mail: carol.ufjf@yahoo.com.br
Was investigated the microtensile bond strength of self-etching adhesive systems in dentin
treated with 2% chlorhexidine digluconate (CHX) in self-etching technique (ST) and totaletching
technique (TT). Occlusal surfaces of 20 human molars were removed to expose middle
dentin. Eight groups were created according to treatments: 1A, Clearfil SE (SE) with ST; 1B,
SE with ST and previous application of CHX; 2A, Scotchbond Universal (SBU) with ST; 2B,
SBU with ST and previous application of CHX; 1C, SE with TT; 1D, SE with TT and previous
application of CHX; 2C, SBU with TT; 2D SBU with TT and previous application of CHX.
A block of composite resin was build (5mm) on hybridized surface, and witch sample was
sectioned in 1mm2 sticks and subjected to microtensile test. After fractures, the samples were
evaluated on Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Analyser
(EDX). ANOVA two-ways and Tukey test (α = 0.05) statistical analysis was performed.
According to results, CHX interfered on ST reducing the bond strength values in groups 1B
(22,86±5,18) and 2B (27,02±5,58) comparing with 1A (39,77±11,56) and 2A (40,84±12,49).
However, the same did not happened in TT, that presented no statistical difference between
groups 1C (25,95±5,43) and 1D (28,09±4,20), 2C (31,53±9,22) and 2D (37,81±11,69).
Analysis by SEM revealed that ST groups presented cohesive adhesive fractures; and TT,
cohesive at the top of the hybrid layer was the most frequent type of fracture. EDX revealed
the presence of CHX crystals for ST, which was not found for TT.
CHX influenced in a negative way on the bond strength of adhesive systems on self-etching
technique.
HA013
Injectability of gray and white Portland cement for dental application
Alandia‐Román CC*, Silame FDJ, Pires‐de‐Souza FCP, Panzeri H
Materiais Dentarios e Prótese - UNIVERSIDADE DE SÃO PAULO - RIBEIRÃO PRETO.
E-mail: ccalandia@usp.br
Portland cement (PC) based Mineral Trioxide Aggregate (MTA) is widely accepted as the
preferred repair material in endodontics. Disposable extrusion devices for MTA are costly
instruments, as an alternative, medical stainless steel needles with similar diameters could be
used. The aim of this study was to evaluate a simple method for placing PC using medical
stainless steel needles and to compare the injectability (I) of white (WPC) and gray PC (GPC).
WPC-GPC containing 20% of Bismuth oxide were mixed with distilled water at powder-toliquid
ratios (PLR) of 3, 3.5 and 4.0g/ml, then placed into a 5ml syringe using needles with
inner diameter of 0.69mm (19G) to deliver the pastes. The percentage of paste extruded was
determined and the compressive strength (CS) and porosity (P) were also evaluated. GPC
was practically fully extruded (I=94.5%) at a PLR of 3g/ml, PLR´s of 3.5 and 4.0g/ml were
still injectable, however, the percentage of extruded cement decreased with increasing PLR´s
(I=84.5% and 60.2%).WPC showed reduced injectability at a PLR of 3g/ml (I=22.9%), PLR´s
of 3.5 and 4.0g/ml were not injectable at all (I=9.8% and 0%). CS and P were inversely
proportional and related to PLR, the increase of water content led to decreased CS and
increased P values for both GPC (CS= 26.9, 39.0and 44.9MPa/ P=22.3, 15.9 and 14.3%) and
WPC (CS= 21.5, 38.0and 40.5MPa/ P=26.3, 18.5 and 13.0%).
It was concluded that only GPC could be made injectable in this study and 19G needles
demonstrated to be a suitable alternative to existing MTA disposable delivery devices. (Apoio:
CAPES)
Braz Oral Res 2014;28(Suppl. 1):22-476 (Proceedings of the 31st SBPqO Annual Meeting) 33