2. Introduction
• Minimal intervention dentistry has recently
become the preferred mode of treatment for
dental caries, and minimal removal based on
clinical diagnosis and controlling further risk of
caries is now recommended.
• In fact, the discussion as to how much tissue
must be removed to arrest the caries process is
not new, and minimal intervention dentistry
still requires an objective diagnostic method
and clinical criteria for minimal removal of
caries.
IwamiY, Hayashi N,Yamamoto H, et al. Evaluating the objectivity of caries removal with a
caries detector dye using color evaluation and PCR. J Dent. 2007;35(9):749-754.
3. • Color and hardness have been used as the criteria for the clinical assessment of
carious dentin.
• In general, during the removal of caries in clinical situations, visual inspection is
used to evaluate the color of carious dentin, and detection with an excavator is used
to evaluate its hardness.
• However, the use of visual inspection and tactile procedures to estimate discoloration
and hardness of remaining dentin may not be a reliable guide,
LundeenTF, RobersonTM. Caries diagnosis and preventive treatment. In: Sturdevant CM, RobersonTM, Heymann JR, Sturdevant JR, eds.TheArt and
Science of Operative Dentistry. 3rd ed. St. Louis: Mosby; 1995:100-106.
4. • The subjective nature of these criteria, differences in assessments
between dentists are likely to result in differences in the quality
and quantity of dentin removed during operative interventions .
• In 1972, a technique using a basic fuchsin red stain was suggested
(and subsequently developed) to aid in the differentiation for the
layers of the carious dentin and today various commercially
available caries detector (CAD) dyes with different chemistries are
used to aid in differentiation of softened dentin
FusayamaT, Okuse K, Hosoda H. Relationship between hardness, discoloration, and microbial invasion in carious dentin. J Dent Res. 1966; 45(4):1033-1046
5. • Caries detector dyes (CDDs) have been used during visual
inspection of carious dentin to increase the objectivity of color
evaluation with the naked eye.
• Some studies have reported CDDs to be useful in overcoming the
difficulties inherent in classical techniques used for identifying
and removing carious dentin to ensure acceptable clinical
excavation by reliably staining irreversibly demineralized dentin
infected with bacteria without staining uninfected dentin.
Singh UP,TikkuA, ChandraA, et al. Influence of caries detection dye on bond strength of sound and carious affected dentin:An in-vitro study. J Conserv
Dent. 2011;14(1):32-35.
6. • However, other studies reported that the use of CDDs may result in excessive
dentin removal because the dyes are unable to discriminate between bacterially
infected and uninfected tissues so that partially demineralized dentin that is
devoid of bacterial infection may be inadvertently removed.
• Boston and Graver showed that the use of CDDs resulted in removal of tissue
beyond the level of bacterial invasion
• Kidd et al. found not only non-caries-specific staining of dentin, but also
increased staining at the enamel-dentin junction and in deeper layers of dentin
closer to the pulp.
Boston DW,Graver HT. Histological study of an acid red caries-disclosing dye. Oper Dent.
1989;14(4):186-192
Kidd EA, Joyston-Bechal S, Beighton D. Microbiological validation of assessments of caries
activity during cavity preparation. Caries Res. 1993;27(5):402-408
7. • In light of this knowledge, to prevent the removal of excessive dentin in
clinical situations, it has been recommended that dentin stained light
pink by CDDs not be removed.
• Although this has become acceptable practice, to date there has been no
detailed study examining the removal of residual dyes from lightly
stained tissue. Before restoration can begin, it is important to remove
CDD residue from stained tissue.
FusayamaT. Clinical guide for removing caries using a caries-detecting solution. Quintessence Int. 1988;19(6):397-401.
8. • A number of different cleaning agents have been suggested for this
purpose, including
- Sodium hypochlorite (NaOCl),
- Hydrogen peroxide (H2O2),
- Distilled water (DW).
• However, there is little knowledge regarding the effectiveness of
cleaning solutions in removing residual dyes.
• Therefore, this study used spectrophotometry to compare the
effectiveness of three different cleaning agents in removing
residual CDDs from the oral cavity.
9. Null
Hypothesis
• The following null hypotheses were examined:
(1) There is no difference between the cleaning
effects of different cleaning solutions;
&
(2) There is no difference between the staining
potential of different CDDs.
10. Materials
&
Methods
Three commercial CDDs
- Seek Caries Indicator (SCI),
- Caries Detector (CD),
- Caries Marker (CM)]
Three cleaning solutions
- Distilled water (DW)
- 3% Sodium Hypochlorite (NaOCl)
- 3% Hydrogen Peroxide
were used in this study
MATERIALS
11. Ninety freshly extracted human third-molar teeth were used in the
study.
Following extraction, teeth were cleaned with pumice to remove
any surface debris or contaminants and were stored in 0.1% thymol
solution at room temperature
Flat dentin discs were prepared from the occlusal surface of
molars by horizontally sectioning crowns 1.5 mm below the
dentin-enamel junction using a diamond disc at slow speed under
continuous water cooling
Specimens were cut to a size of 6 × 6 × 2 mm for ease of viewing
in a spectrophotometer window and then stored in distilled water
until use.
12. Specimens were divided into 3 groups
N=90
Group I
Seek Caries Indicator
n= 30
Group II
Caries Detector
n=30
Group III
Caries Marker
n=30
DistilledWater
(n= 10)
3% Sodium
Hypochlorite
(n=10)
3% Hydrogen
Peroxide
(n=10)
14. • Dentin surfaces were wiped with cotton pellets, and a
disposable brush was used to apply 1 drop of CDD to the dentin
surface of each sample.
• After 10 seconds, the CDDs were carefully cleaned for 10
seconds using a sponge pledget moistened with one of the
cleaning solutions
15. • A spectrophotometer (Vita Easyshade® Compact, Vident,
Brea, California) was used to measure the color of each
specimen
- Before CDD application (baseline)
- Immediately after cleaning.
• Samples were placed against a black background, and
color was measured from the central region of each
sample, with the tip of the spectrophotometer probe placed
at 90 to the central region of the dentin surface.
16. • All measurements were performed according to the manufacturer's instructions
by a single investigator (EG) experienced with use of the device.
• The spectrophotometer was calibrated by placing the probe tip on the calibration
port aperture prior to each measurement, and when two consecutive, identical
readings were generated, the value was accepted as the color measurement for
that sample, in line with the manufacturer's instructions.
17. Measurements were recorded using the Commission International del'Eclairage (CIE)
L*a*b* system, which measures color relative to a standard illuminant (A) against a
white background.
L* represents the lightness coordinate, with values ranging from 0 (black) to 100
(white);
a* and b* represent chromaticity coordinates along a red-green and yellow-blue axis,
respectively,
- Positive A* Values Indicating A Shift To Red,
- Negative A* Values A Shift To Green,
- Positive B* Values A Shift To Yellow, And
- Negative B* Values A Shift To Blue
19. Statistical
analysis
■ Assumptions of normal distribution
(Kolmogorov-Smirnov tests) were
checked for all the variables tested.
■ Data were analyzed by two-way analysis
of variance (ANOVA) and Tukey's HSD
tests (α = .05).
■ All statistical analysis was performed
using the statistical software SPSS for
Windows, Version 12.0.1 (SPSS Inc,
Chicago, Illnois).
20. Results
■ ANOVA results indicated that both CDD and
cleaning solutions had significant effects on
color change (P < .0001); however, there was
no significant interaction between the two
factors (P = .26).
■ Means and standard deviations of color
changes (ΔE*) and differences between the
CM, CD, and SCI group are listed.
22. • Statistically significant differences were observed between
cleaning agents for all CDDs groups (P < .05), with the smallest
color change observed in the 3% NaOCl sub-groups (P < .05)
and the largest in the DW sub-groups (P < .05).
• Moreover, SCI yielded significantly higher ΔE* values when
compared to CM and CD for all 3 cleaning sub-groups (P < .05).
23. Discussion
■ The present study found significant
differences between the effectiveness of the
3 different cleaning agents tested; thus, the
first null hypothesis was rejected.
■ For each of the CDDs tested, discoloration
was greater for the sub-groups cleaned with
distilled water and with 3% H2O2 when
compared to the sub-group cleaned with 3%
NaOCl.
24. • Furthermore, ΔE* values for the SCI groups were higher than those of the
other CDD groups for all 3 cleaning sub-groups (P < .05); thus, the second null
hypothesis regarding the staining potential of CDDs was also rejected.
• The modern concept of “minimal-invasive dentistry” calls for more
conservative removal of highly infected and irreversibly demineralized
carious tissue, with selective caries excavation geared towards preventing
lesion progression while maintaining the strength and stability of the
remaining tooth structure to guarantee long-term mechanical resistance
against intra-oral forces.
Tyas MJ, Anusavice KJ, Frencken JE, et al. Minimal intervention dentistry–a review. FDICommission Project 1-97. Int Dent J. 2000; 50(1):1-12.
25. • However, identifying the point at which caries excavation should end and restoration
begin is often clinically challenging. CDDs have been suggested as a possible solution
to this problem.
• Hydrogen Peroxide (H2O2) has been used in dentistry for more than 70 years for
cleaning, bleaching and disinfection, with its most common use as an oxidizing agent
applied directly to the tooth for bleaching purposes.
• The oxidizing capacity of H2O2 is controlled by the substrate and reaction environment
(i.e., temperature, pH and light).
Joiner A.The bleaching of teeth: a review of the literature. J Dent. 2006;34(7):412-419.
26. • Under alkaline conditions, H2O2 acts as a strong oxidizing agent
through the formation of free radicals, reactive oxygen molecules and
hydrogen peroxide anions.
• The 3% H2O2 used in this study has been recommended by the
manufacturer as a cleaning agent; however, it was less successful in
cleaning residual CDDs when compared to 3% NaOCl.
• This may be explained by the fact that CDDs contain a mixture of
dyes and alcohol derivatives, which is incompatible with oxidizing
agents like 3% H2O2.
Rossi-Fedele G, GuastalliAR. Effect of an alcohol-based caries detector on the surface tension of sodium hypochlorite preparations. Braz Dent
J. 2015;26(1):66-68.
27. • Distilled water is a commonly available material used to clean
debris and discolorants.
• It is also commonly used as a negative control agent in laboratory
studies because it does not modify the organic or inorganic
contents of dental tissue; hence, it is not surprising that this study
found DW to be unsuccessful in removing residual CDD from
dentin.
28. Sodium Hypochlorite (NaOCl) is a well-known disinfectant that has been reported to
- Clean Bacteria & Dentinal Debris,
- Denature Toxins By Dissolving Tissue
- Interfering With The Integrity Of The Cytoplasmic Membrane By
Irreversibly Inhibiting Enzyme Production
&
-Destroy Phospholipids Produced During Lipid Peroxidation.
• NaOCl successfully reduced the stains but not completely remove from the teeth
surfaces.
Ranly DM, Garcia-Godoy F. Current and potential pulp therapies for primary and young permanent teeth. J Dent. 2000;28(3):153-161.
29. • Even so it can be used in the oral cavity as a cleaning solution, and in
fact, the present study demonstrated a low concentration of NaOCl
(3%) can used to sufficiently remove residual CDD stains.
• However, clinicians must remain aware that exposure to NaOCl in
high concentrations can have a negative effect on dentin mechanical
properties, decreasing microhardness and increasing roughness.
Ari H, ErdemirA, Belli S. Evaluation of the effect of endodontic irrigation solutions on the microhardness and the roughness of root
canal dentin. J Endod. 2004;30(11):792-795.
30. • The results of the present study found that in comparison to baseline, dentin discoloration
caused by CDD application persisted even after cleaning.
• This may be related to the fact that each of the CDDs tested contains a glycol-based
solvent.
• Propylene glycol is a dihydric alcohol that allows the dye to penetrate very quickly and
deeply into the dentin.
• The low surface tension and higher diffusional nature of propylene glycol may result in
over-staining of the dentin.
Cruz EV, Kota K, Huque J, et al. Penetration of propylene glycol into dentin. Int Endod J. 2002;35(4):330-336.
31. • As a recent study noted, decreasing surface tension of the alcohol decreasing
surface tension of the alcohol based CDDs, it may limit the success of cleaning
agents.
• The differences in dyeing potential among the CDDs may be due to differences in
the molecules weight of the different colorants used.
• Specifically, dyes with lower molecule weight have been shown to exhibit higher
diffusional properties in porous tissues so that CDD dyes of low molecular weight
may over-stain dentin.
CvetkovicA, Picioreanu C, Straathof AJ, et al. Relation between pore sizes of protein crystals and anisotropic solute
diffusivities. J Am Chem Soc. 2005;127(3):875-879.
32. • This would explain why no statistically significant difference was found in the
staining potential of CD and CM, which contain the same colorant, whereas SCI,
which contains a different staining agent, exhibited significantly higher staining
potential.
• However, it is more likely due to the factors
(A) The affinity of the different dye mixtures with dentin tissue
(b) The overall absorption spectrum of the dyes
(as different dyes can absorb light differently at the same dye concentration – some
absorb light more than others).
33. In sum, within the limitations of this in vitro study, 3% NaOCl may be recommended
for use in cleaning residual CDDs from healthy and affected dental tissue.
However, it should be noted that this study was conducted with intact dental tissue, and
it would be wrong to assume that similar results will be obtained for caries-affected
tissue.
Considering that previous studies have shown dye solutions to easily penetrate into
more porous dental tissue, it is likely that caries affected dentin, which is less
mineralized and more porous than healthy dentin, would be much more readily stained
by CDDs.
34. • To achieve a selective and accurate staining of carious tissue dyes having
specific reactivity to carious specific functionalities should be used.
• Dyes having electrostatic bonding properties (Acid Red and Food Blue) have
been shown not to be selective in contrast to dyes carrying a hydrazine group
(Alexa Fluor 594 and LuciferYellow CH, Amino fluorescein) which bind
specifically to an ester- function in the carious tissue in a covalent manner.
OHDM -Vol. 14 - No. 4 - August, 2015
35. • Therefore, they concluded that modified proteins such as ester
functional groups in carious dentine can be stained with dyes carrying
a hydrazine group, thereby acting selectively in distinguishing
between sound and carious dentine.
• Moreover, a selective and covalently bonded dye will not stain
unaffected dentine and will be a support in judging the clinical end
point during caries excavation.
36. • Clinicians need to remain aware of the potential
discoloration associated with the use of CDDs and further
studies should be performed to provide more detailed
information about the effectiveness of cleaning agents used
in removing residual CDDs from affected dental tissue.
Because of potential carcinogenicity, the basic fuchsin stain was subsequently replaced by another dye, acid red solution
The study protocol was approved by the Ethics Committee of the Ondokuz Mayıs University Faculty of Dentistry (2016/345).
n statistics, test is a nonparametric test of the equality of continuous, one-dimensional probability distributions that can be used to compare two samples. It is named after Andrey Kolmogorov and Nikolai Smirnov. It shows maximum absolute difference between the two cumulative distribution function.
Tukeys It can be used to find means that are significantly different from each other.
Statistically significant differences were observed between cleaning agents for all CDDs groups (P < .05), with the smallest color change observed in the 3% NaOCl sub-groups (P < .05) and the largest in the DW sub-groups (P < .05) Moreover, SCI yielded significantly higher ΔE* values when compared to CM and CD for all 3 cleaning sub-groups ( < .05).
