74717284

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.

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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

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.

Dent Child 1999;66:238–242.

15. Sari S, Ozalp N, Ozer L. The effect of formocresol on bond strength of adhesive materials to primary dentine. Oral Rehabil 2004;31:671–674.

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17. Atash R, Vanden Abbeele A. Bond strengths of eight

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