Q U I N T E S S E N C E I N T E R N AT I O N A L
Influence of pulpotomy medicaments on the ultrastructure and shear bond strength of a self-etch adhesive to primary tooth dentin Hanaa Shalan, DDS1/Salwa Awad, DDS2/ Abeer Abd-El Sallam El-Fallal, DDS3
Objective: To compare the effect of the pulpotomy medicaments glutaraldehyde, ferric sulfate, and formocresol on the structure and shear bond strength of a self-etch adhesive to the dentin of primary teeth. Method and Materials: Forty human primary molars were sectioned mesiodistally and divided into four groups: group I (control group), dentin specimens were soaked in distilled water for 48 hours; group II, dentin specimens were soaked in 2% glutaraldehyde; group III, dentin specimens were soaked in formocresol; and group IV, dentin specimens were soaked in 15.5% ferric sulfate. All specimens were rinsed with tap water and dried with air. AdheSE One (a self-etch adhesive) and Valux Plus composite resin were applied to the dentin surfaces. The molecular structure PG UIF BEIFTJWF JUTFMG BOE BEIFTJWF XJUI DPNQPTJUF SFTJO XFSF UFTUFE VTJOH BO '5*3 spectrometer. Shear bond strength was tested with a universal testing machine. Failure modes analyses were performed with a scanning electron microscope (SEM). Results: Glutaraldehyde showed little changes in the molecular structure of the adhesive itself and adhesive with composite. However, ferric sulfate and formocresol affected the molecular structure of the adhesive alone and the adhesive with composite. The highest mean value of shear bond strength was for the glutaraldehyde group (11.17 ± 4.87 MPa). Ferric sulfate and formocresol significantly reduced shear bond strength after the application of pulpotomy medicaments (7.45 ± 3.73 and 5.31 ± 3.30 MPa, respectively). SEM analysis revealed that most of the specimens failed in cohesive and mixed modes. Conclusion: This study revealed that formocresol and ferric sulfate adversely affect the shear bond strength and molecular structure of the adhesive system to primary dentin. (Quintessence Int 2012;43:517–523)
Key words: bond strength, ferric sulfate, formocresol, glutaraldehyde, infrared, pulpotomy medicaments
In pediatric dentistry, pulpotomy is the
on the enamel of succedaneous teeth.3
most widely accepted clinical procedure
To avoid these harmful effects, alternative
for endodontically treating primary teeth.1
agents for vital pulpotomy procedures are
Formocresol has been widely used as a
being sought. Glutaraldehyde is consid-
pulpotomy agent in pediatric dentistry.2
ered a substitute for formocresol in primary
/VNFSPVT QSPCMFNT IBWF CFFO JEFOUJ-
teeth because of its better tissue fixative
fied with the application of formocresol,
properties and superior crosslinking abili-
including postoperative systemic transport
ties.4 Two percent buffered glutaraldehyde
of the medicament and possible effects
was an effective agent and showed high success rates in the pulpotomy of pri-
1
2
3
Lecturer,
Department
of
Pediatric
Dentistry,
Mansoura
mary teeth.5 Ferric sulfate has received
University, Mansoura, Egypt.
some attention as a pulpotomy agent.6–8
Associate Professor, Department of Pediatric Dentistry,
It has demonstrated good clinical and
Mansoura University, Mansoura, Egypt.
radiographic success in human clinical
Associate Professor, Department of Dental Materials, Mansoura
trials.9 A clinical study compared the effec-
University, Mansoura, Egypt.
tiveness of ferric sulfate to formocresol and
Correspondence: Dr Abeer Abd-El Sallam El-Fallal, Department of Dental Materials, Faculty of Dentistry, Mansoura University, Gomhouria St, Mansoura 35516, Egypt. Email: elfallal3@ yahoo.com, elfallal3@mans.edu.eg
VOLUME 43 t /6.#&3 6 t +6/& 2012
showed that the success rates were 85% and 86% for formocresol and ferric sulfate, respectively.10
517
Q U I N T E S S E N C E I N T E R N AT I O N A L Shalan et al
Traditionally, pulpotomized primary teeth
compressed air for 5 seconds. The experi-
have been restored with stainless steel
mental group specimens were soaked for 48
DSPXOT 3FUSPTQFDUJWF TUVEJFT IBWF TIPXO
hours14 in 2% glutaraldehyde (QuantomiX)
higher success rates for teeth restored with
(group II), formocresol (Produits Dentaires)
stainless steel crowns than those restored
(group
with amalgam or composite.11,12
(Astringedent,
III),
and
15.5%
Ultradent)
ferric (group
sulfate IV).
All
However, stainless steel crowns require
specimens were rinsed with tap water for 15
removal of sound tooth structure not directly
seconds and dried with oil-free compressed
involved in the decay process, thereby
air for 5 seconds before bonding.
resulting in increased susceptibility to tooth
Masking tape with a circular hole (3 mm
fracture. They also provide an unesthetic
in diameter) was applied to the prepared
solution to the clinical problem.13
dentinal surface so the dentin adhesive was bonding
applied to a standardized area. The applica-
agents, a previous study has demonstrated
tion of the adhesive system (AdheSE One,
that bonded restoration of pulpotomized
Ivoclar Vivadent) was carried out according
primary teeth strengthens the remaining
to the manufacturer’s instructions.
With
the
development
of
tooth structure.14 However, the cresol com-
A polytetrafluororethylene mold (3 mm
ponent of formocresol leads to a reduction
in diameter and 3 mm in height) was
in the bond durability of composite resin
used to build the composite resin cylinders
and dentin-bonding systems.15,16
(Valux Plus composite resin, 3M ESPE)
To date, the biochemical effects of the
perpendicular to the dentinal surface of
pulpotomy medicaments formocresol, glu-
all specimens (Fig 1) in a two-layer incre-
taraldehyde, and ferric sulfate on the bond
ment technique. Composite cylinders were
strength of adhesive restorations in primary
cured using a light-curing unit (Visilux2,
teeth have been uncertain. Therefore, this
3M
study was undertaken to determine the
closed containers filled with distilled water
effect of surface contamination with the
at 37°C for 24 hours.
ESPE).
Specimens
were
stored
in
different pulpotomy medicaments on the structure and shear bond strength of den-
FTIR spectrum
tin-bonding agents to primary teeth.
The molecular structure of the junction region (adhesive and dentin, as well as composite, adhesive, and dentin without and with pulpotomy medicaments) was
METHOD AND MATERIALS
FWBMVBUFE VTJOH B .BUUTPO '5*3 Spectrometer in the Spectral Analysis Unit, Chemistry Department, Faculty of Science,
Forty noncarious human primary molars
Mansoura University, Mansoura, Egypt.
were stored at room temperature in an aqueous solution of 1% chloramine for no longer
Shear bond strength test
than 3 weeks before use.16 The crowns
The shear bond strength determined using
were sectioned longitudinally in a mesiodis-
B VOJWFSTBM UFTUJOH NBDIJOF *OTUSPO 3
tal direction using diamond disks with water
Instron) at a crosshead speed of 1 mm/min
coolant. The buccal and lingual surfaces
using a blade parallel to the adhesive inter-
of the crowns were embedded in autopo-
face between the adhesive and dentin (Fig
lymerizing resin, with the buccal or lingual
2).14 The values were calculated by dividing
surfaces exposed. Dentin surfaces were
the peak load at failure by the specimen
ground flat with 180- to 600-grit sandpaper
surface area and expressed in MPa.
to obtain a flat dentinal surface. A total of 80 dentin surfaces were randomly allocated into
Fracture analysis
one control and three experimental groups
Fractured specimens were examined by
of 20 specimens each. In group I (control
using a scanning electron microscope (SEM)
group), dentin specimens were soaked in
(LEO 435 VP, Leo Electron Microscopy) to
distilled water for 48 hours, rinsed with tap
identify the mode of bond failure (adhesive,
water for 15 seconds, and blown dry with
cohesive, or a combination).
518
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Q U I N T E S S E N C E I N T E R N AT I O N A L Shalan et al
Fig 1 Specimen mounted in a composite resin cylinder. Fig 2 (right) Shear bond strength test using a universal testing machine.
Statistical analysis
$ ) CFDBNF XFBL BOE / ) CBOET CFDBNF
Descriptive data were analyzed using SPSS
medium strength and split. Formocresol
*#. .FBO WBMVFT TUBOEBSE EFWJBUJPOT
mainly affected C-C, which also became
POF XBZ BOBMZTJT PG WBSJBODF "/07" BOE
XFBL 5IF / ) CBOE DIBOHFE UP NFEJVN
the Student t test were calculated. Statistically
and broad compared with the control (adhe-
significant differences were set at P ≤ .05.
TJWF XJUIPVU NFEJDBNFOUT $ 0 $ $ / ) and C-H represent the organic structure of dentin, adhesive, and composite resin.) In Fig 4, the junction region presents
RESULTS
'5*3 DIBSBDUFSJTUJDT PG DPNQPTJUF BEIFsive, and dentin. Glutaraldehyde showed
FTIR spectrum
MJUUMF DIBOHFT JO UIF '5*3 TQFDUSVN IPX-
'5*3 TQFDUSPTDPQZ SBOHFE GSPN UP
ever, ferric sulfate showed changes in the
4,000 cm-1. The infrared spectra of the
bands, which became less strong than the
junction region of all four groups are shown
control group. Splitting of the C-O band
in Figs 3 and 4. Figure 3 shows penetra-
and shifting of the overlapped bands occur.
tion of medicaments through the adhesive
Also, the C-H band became slightly sharper
layer, leading to changes in the band length
than in the control group. Formocresol
(stretching) and changes in the band angle
produced changes to the carbonate band
(bending). Glutaraldehyde affected the C-O
where shifting occurs. The overlapped C-H
band, where shifting occurred from 1,049
BOE / ) CBOET CFDBNF XFBLFS UIBO UIF
to 1,041 cm-1, and it had medium intensity
control group.
compared with the control group without
Table 1 shows means and standard
medicaments. Slight shifting of C-C and
deviations of the shear bond strength val-
/ ) CBOET GSPN UP DN-1 and
ues for each group. Intergroup comparison
3,417 to 3,444 cm-1 occurred. However, the
(Table 2) showed a statistically significant
C-H band showed no change. Ferric sulfate
difference in shear bond strength between
affected the C-O band where it became
groups I and III, groups II and IV, and
sharp and strong. Shifting of C-C occured.
groups II and III (P < .05).
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519
Q U I N T E S S E N C E I N T E R N AT I O N A L Shalan et al
a
a
b
b
c
c
d
d
Fig 3 Molecular structure of the junction region (adhesive and dentin with and without pulpotomy medicaments). (a) Control, (b) glutaraldelhyde, (c) formocresol, and (d) ferric sulfate.
Table 1
Mean values and SDs of shear bond strength in MPa for different groups
Fig 4 Molecular structure of the junction region (composite as well as adhesive and dentin with and without pulpotomy medicaments). (a) Control, (b) glutaraldelhyde, (c) formocresol, and (d) ferric sulfate.
Table 2
Comparison of the shear bond strengths of different groups
Groups
Mean ± SD
Groups
t test
P value
I
9.59 ± 4.44
I vs II
1.72
.29
II
11.17 ± 4.87
I vs III
3.45
.001*
III
5.31 ± 3.30
I vs IV
1.65
.10
IV
7.45 ± 3.73
II vs III
2.30
.02*
II vs IV
2.71
.01*
III vs IV
1.918
.06
SD, standard deviation.
P > .05, no significant difference between two groups. *Indicates that the values are statistically significant
Table 3
different from each other.
No. of specimens with different modes of failure
Groups
C
M
A
I
2
5
3
II
12
7
1
III
6
8
6
IV
8
7
5
C, cohesive failure; M, mixed; A, adhesive failure.
520
Modes of failure for the adhesive system are presented in Table 3. The SEM evaluation revealed that most of the specimens failed in cohesive and mixed modes. Few showed adhesive failure, which is illustrated in Fig 5.
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Q U I N T E S S E N C E I N T E R N AT I O N A L Shalan et al
a
b
c
Fig 5 SEM showing modes of failure. (a) Cohesive failure within the bonding layer, (b) mixed failure with maintenance of composite over half of the specimen, and (c) adhesive failure revealing open dentinal tubules.
DISCUSSION
junction region with the dentin occurred. This may explain the insignificant increase in the shear bond strength. This result is
Pulpotomy is the accepted therapy for the
in agreement with the results of Cilli and
management of cariously exposed pulps
Prakki,21 who reported that glutaraldehyde
8
in symptom-free primary molars. For long-
primer application may affect demineralized
term success of pulpotomized teeth, strong
dentin properties and improve resin-dentin
durable bonds at the restoration-tooth inter-
bond strength. However, other studies22,23
face are necessary. A self-etch adhesive
have shown that glutaraldehyde decreases
system was used in this study, since there
the shear bond strength of adhesives to
is a trend away from older multicompo-
bovine dentin.
nent bonding systems toward simplified
For the ferric sulfate and formocresol
consolidated adhesives. With a self-etch
groups, there were marked changes in
approach, there are no individual etching,
the structure of the adhesive alone and
rinsing, and drying steps, which reduces
adhesive and composite resin at the junc-
not only the clinical application time but also
tion region with the dentin, which may
the sensitivity of the technique and the risk
explain the significant reduction in shear
of manual errors during the application pro-
bond strength compared with the control
cess.17 Composite resins were introduced in
group. Several studies have reported that
pediatric dentistry as restorative materials,
ferric sulfate decreased the bond strength
and as a result of their esthetic, physical,
of adhesives on primary dentin. A suit-
and mechanical properties, as well as a low
able explanation for reduced shear bond
resistance to bulk fractures, they can be
strength was due to the chemical reaction
accepted as an alternative to glass iono-
of iron and sulfate ions with blood proteins,
mers and compomer restorative materials.18
causing coagulation of collagen or plasma
Infrared spectroscopy is based on the
proteins in dentinal fluid, which affected
interaction between electromagnetic radia-
the dentin surface architecture and bond
tion and natural vibrations of the chemical
strength.24â&#x20AC;&#x201C;26
bonds among the atoms that compose the
have shown that formocresol decreased
matter. For a material to absorb radiation in
the bond strength of adhesives on pri-
the infrared region, two conditions should be
mary dentin. The authors speculated that
fulfilled: There must be coincidence (reso-
inhibition of polymerization is the greatest
nance) among the frequencies of the infra-
cause of the reduced bond strength by
red radiation and molecular vibration, and
formocresol, since when it is present on
the natural vibration must cause a change
the dentin surface, it reacts with radicals
in the dipole moment during vibration.19,20
and inhibits polymerization. Therefore, the
Also,
several
studies16,24,27
For the glutaraldehyde group, it was
mechanical strength of resin is decreased
found that few changes in the structure of
at the resin-dentin interface, which affects
the adhesive and composite resin at the
bond strength.
VOLUME 43 t /6.#&3 6 t +6/& 2012
521
Q U I N T E S S E N C E I N T E R N AT I O N A L Shalan et al
SEM evaluation of the failure mode after
5. Shumayrikh NM, Adenubi JO. Clinical evaluation of
shear bond strength testing showed a pre-
glutaraldehyde with calcium hydroxide and glu-
dominance of cohesive failure on dentin surfaces. These results are in accordance with previous studies.14,28 However, a study
taraldehyde with zinc oxide eugenol in pulpotomy of primary molars. Endod Dent Traumatol 1999;15: 259–264. 6. Gravenmade EJ. Some biochemical considerations
by O‘Keefe et al29 found no correlation
of fixation in endodontics. J Endod 1975;1:233–237.
between the mode of bond failure and
7. Kopel HM, Bernick S, Zachrisson E, DeRomero SA.
bond strength values. Therefore, correlation
The effects of glutaraldehyde on primary pulp tis-
between the mode of bond failure and bond
sue following coronal amputation: An in vivo histologic study. ASDC J Dent Child 1980;47:425–430.
strength values was attempted.
8. Ranly DM, Garcia-Godoy F, Horn D. Time, concentration and pH parameters for the use of glutaraldehyde as a pulpotomy agent: An in vitro study. Pediatr Dent 1987;9:199–203.
CONCLUSION
9. Ibricevic H, Al-Jame Q. Ferric sulfate as pulpotomy agent in primary teeth: Twenty month clinical follow-up. Clin Pediatr Dent 2000;24:269–272.
The following four points can be concluded from the results of this study:
10. Hutch KC, Paschos E, Hollwick R, Crispin A. Effective ness of four pulpotomy techniques. Randomized control trial. J Dent Res 2005;84:1144–1148.
1. Glutaraldehyde
showed
the
highest
11. Holan G, Fuks A, Keltz N. Success rate of formocresol
mean value of the shear bond strength
pulpotomy in primary molars restored with stain-
and little change in the structure of the
less steel crowns vs amalgam. Pediatr Dent 2002;
adhesive and composite resin at the dentin junction. 2. Ferric sulfate and formocresol showed significant
reduction
24:212–216. 12. Guelmann
in
shear
bond
M,
McIlwain
MF,
Primosch
RE.
Radiographic assessment of primary molar pulpotomies restored with resin-based materials. Pediatr Dent 2005;27:24–27.
strength and marked changes in the
13. Srinivasan V, Patchett CL, Waterhouse PJ. Is there
structure of the adhesive and composite
life after Buckley‘s formocresol? Part I: A narrative
resin at the dentin junction.
review of alternative interventions and materials.
3. SEM analysis showed a predominance
Int J Pediatr Dent 2006;16:117–127.
of cohesive failure on dentin surfaces
14. El-Kalla IH, Garcia-Godoy F. Fracture strength of
after the application of pulpotomy medi-
adhesively restored pulpotomized molars. ASDC J
caments. 4. Formocresol and ferric sulfate adversely affect the molecular structure of the adhesive system of primary dentin.
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