BAOJ Dentistry
Sneha Sreedhar and Rashmi Nayak, BAOJ Dentistry 2017, 3: 1
3: 024
Research
A Comparative Assessment of Hydroxyl and Calcium Ion Diffusion from Calcium
Hydroxide Based Intracanal Medicaments in Primary Teeth - An In Vitro Study
Sneha Sreedhar1* and Rashmi Nayak2
Consultant pediatric dentist, Bhaktivedanta Hospital, Mumbai, India.
1
pedodontics and preventive dentistry, Manipal College of dental sciences, Manipal, India
2
Abstract
Aim
The aim of the present study was to compare and determine
quantitatively the diffusion of hydroxyl ions and calcium ions
through radicular dentin and cementum from three different
vehicles of calcium hydroxide pastes when used in primary teeth.
Material and Methods
60 roots of extracted primary molar teeth (20 per group) were
collected. The chemo-mechanical preparation was done. The teeth
were divided into 3 groups of different vehicles: (1) Group A (n=20)
- Calcium hydroxide with distilled water; (2) Group B (n=20)Calcium hydroxide with 0.2% chlorhexidine solution and (3)
Group C (n=20)-Calcium hydroxide with propylene glycol in form
of premixed syringes (Diapaste). The specimens were suspended in
deionised water .Diffusion of the Calcium ions and Hydroxyl ions
was determined using a digital pH meter and atomic absorption
spectrometer at 24 hours, 7 days and 14 days respectively.
Results
Two-way analysis of variance and Turkey’s test revealed that the
difference between the study groups was statistically not significant
with regards to pH and hydroxyl ion diffusion at end of study
period. However, for Group A, B achieved significantly higher
pH and hydroxyl ion values (P<.001), followed by Group C in the
seven day time period. In the calcium ion diffusion, a statistically
significant difference was observed with group C showing highest
release at the end of the study period.
Conclusion
All three formulations showed favorable results in terms of pH and
hydroxyl ion concentrations .However, propylene glycol proved
better as a vehicle in terms of slow and sustained action.
Keywords: Calcium Hydroxide; Endodontics; pH; Vehicle
Introduction
Endodontic treatment constitutes the last clinical resort for
maintaining primary teeth in the oral cavity. In order, to achieve
success with endodontic treatment it is necessary that all phases
be carried out with the aim of healing the periradicular tissues and
elimination of infection from the root canal system .The temporary
nature of the primary tooth does not justify conducting precarious
treatments where biologic principles are overlooked or neglected [1].
BAOJ Dentistry, an open access journal
Due to the tortuous and ribbon shaped anatomy of the primary
teeth, the clinician must rely primarily on chemical cleansing and
sterilization and secondarily on mechanical instrumentation [2].
In these clinical situations, the use of intra-canal medication is
required to complement the disinfection of the root canal system,
dentin tubules, and external surface of the root apex, which cannot
be achieved by chemo-mechanical preparation alone[3].
Calcium hydroxide is the most commonly used intra-canal
medicament. The role of calcium hydroxide in endodontics as a
medicament includes its ability to induce hard tissue formation,
intra-tubular occlusion, antibacterial actions and tissue-dissolving
capability [4]. It is suggested that calcium hydroxide placement in
the root canal elevates the pH, producing an alkaline environment
in the surrounding tissues by the diffusion of hydroxyl ions
through the dentinal tubules [5].When dissolved in water, calcium
hydroxide dissociates into hydroxyl ions and calcium ions. Both
Calcium and hydroxyl ions have a role in the healing process. The
presence of hydroxyl ions in a solution makes it alkaline and thus
antimicrobial and inhibits osteoclastic activity as well [6].
To be effective, calcium hydroxide has to be adequately placed
and condensed into the root canal space, in combination with a
carrying vehicle. Therefore, the type of vehicle used may either
facilitate or inhibit the ionic dispersion of the paste. Vehicles
commonly used are classified as aqueous, viscous, and oily. The
aqueous vehicle promotes a high degree of solubility. Viscous
water-soluble substances release ions more slowly for extended
periods. Oily vehicles that are non-water soluble provide the lowest
solubility and diffusion of the paste [7].
Considering the sparse studies reported in literature regarding
*Corresponding author: Sneha Sreedhar, Consultant pediatric dentist,
Bhaktivedanta Hospital,Mumbai, India, E-mail: [email protected]
Sub Date: January 14, 2017, Acc Date: February 2, 2017, Pub Date: February 8, 2017.
Citation: Sneha Sreedhar and Rashmi Nayak (2017) A Comparative Assessment of Hydroxyl and Calcium Ion Diffusion from Calcium Hydroxide
Based Intracanal Medicaments in Primary Teeth - An In Vitro Study. BAOJ
Dentistry 3: 024.
Copyright: © 2017 Sneha Sreedhar and Rashmi Nayak. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Volume 3; Issue 1; 024
Citation: Sneha Sreedhar and Rashmi Nayak (2017) A Comparative Assessment of Hydroxyl and Calcium Ion Diffusion from Calcium
Hydroxide Based Intracanal Medicaments in Primary Teeth - An In Vitro Study. BAOJ Dentistry 3: 024.
effects of calcium hydroxide based intra-canal medicaments in
primary teeth, the present study was undertaken. Thus the aim
of the present study was to compare and determine quantitatively
the diffusion of hydroxyl ions and calcium ions through radicular
dentin and cementum from three different vehicles of calcium
hydroxide pastes. The objectives were to determine maximum pH
obtained and time taken to reach the maximum pH, to quantify the
diffusion of hydroxyl and calcium ions. The hypothesis suggested
was null hypothesis that there is no difference in the diffusion
of hydroxyl and calcium ions from the three different calcium
hydroxide formulations in the primary teeth.
Methods
This study was approved by Institutional Ethics Committee, Kasturba Hospital, Manipal (process no. IEC 509/2012).
Sample size calculation.
The study was based on demonstrating a 5% difference of diffusion
of ions in between the groups, which was thought to be significant.
To give 80% power and a 5% significance level using a two sided
ANOVA test, a sample size of 15 in each group was calculated as
sufficient to detect the difference between the groups.
Sample Selection
To generate minimum of 15 samples per group a convenient
sample of 60 (20 in each group) was decided. For this purpose,
120 freshly extracted primary molar teeth were collected. The soft
tissue remnants on the tooth were removed with a soft brush and
stored in saline. The teeth were examined under stereomicroscope
(20 x magnifications, Speed fair company, Hong Kong) to rule out
surface resorption and furcation defects.
Page 2 of 8
2.Roots with single patent root canals. Exclusion criteria: Teeth
with perforation, resorption on their apical, middle or cervical
thirds of the roots
The specimens were obtained by transverse sectioning of the crown
2.0 mm coronal to the cement-enamel junction using a doubleface diamond disk (DENTSPLY, India) under water coolant. The
preparation of the entrance of the canal was done with Endo Access
bur. (DENTSPLY, India). The patency of the canals was ensured
using no 10K file .At this stage, 20 roots which had more than
one canal were excluded .Hemi-sectioning was carried out using
a double-face diamond disk under water coolant . Each root was
considered as a new specimen. The samples were stored in saline
solution at room temperature until further use.
Chemo-Mechanical Preparation
Each canal was individually shaped with 21mm K files (DENTSPLY,
India). Bio-mechanical root canal preparation was done using
series of files till no 35 K files. Irrigation was done during the chemo
mechanical preparation with 2.5 ml of 1% sodium hypochlorite
solution (Medilise chemicals, India) in each canal. At the end,
1ml of 17% EDTA (Pulp dent ,India) for 3minutes was used for
removal of smear layer and thereafter washing with saline[8] .The
samples were then randomized using simple randomization into
three groups based on the formulation to be used in the study.
There were 3 groups in the present study:
Group
Root canal filling material
A
Calcium hydroxide with distilled water
B
Calcium hydroxide with 0.2% chlorhexidine
C
Calcium hydroxide mixed with propylene glycol in form of
premixed syringes (Diapaste)
Preparation of Medicament
Electronic high precision balance (Sartorius, Germany) (Figure2)
was used for weighing of the medicament -Calcium hydroxide
powder (Deepthi Dental Products, India). After the calibration of
the instrument, Calcium hydroxide powder was weighed to 0.5 gms
and packed into sachets of butter paper. The paste was prepared in
the three groups as follows ; Group A: The paste was prepared by
mixing 0.5 gm of calcium hydroxide and 0.5 ml of distilled water
(Manipal Pharmaceutical Products, India) just prior to placement
of medicament.; Group B:The paste was prepared by mixing 0.5gm
of calcium hydroxide and 0.5 ml of a 0.2% chlorhexidine (Icpa
Health Products Ltd ,India) solution just prior to placement of
medicament; Group C: Diapaste(Diadent international, USA &
Canada) is an iodo form-free premixed calcium hydroxide, barium
sulfate paste with propylene glycol base.
Figure 1: High precision electronic balance
80 intact roots of extracted primary molar teeth were selected
based on the following inclusion criteria:
1.Primary molar teeth which are grossly decayed and un-restorable
with root intact.
BAOJ Dentistry, an open access journal
Volume 3; Issue 1; 024
Citation: Sneha Sreedhar and Rashmi Nayak (2017) A Comparative Assessment of Hydroxyl and Calcium Ion Diffusion from Calcium
Hydroxide Based Intracanal Medicaments in Primary Teeth - An In Vitro Study. BAOJ Dentistry 3: 024.
Page 3 of 8
7, before and after measurements of each time period. Before
each reading, the medium was homogenized by shaking the vial
to ensure uniform distribution of the hydroxyl ions. The pH was
determined by placing the pH electrode fully immersed in the
deionized water in each sample bottle, stirring the solution for 10
seconds and then recording the pH level. For each measurement,
the electrode of the pH meter was carefully rinsed with deionized
water and dried with absorbent paper to eliminate any residues
that might interfere with the measurements.
Figure 2: Digital pH meter
Placement of the medicament
Pre weighing of the samples before the placement of the medicament
was done using high precision electronic balance. The samples
were dried with paper points. Medication was then carried into
the root canal with 20K file for groups A and B. Premixed syringe
was used for samples of group C. The paste was further condensed
with an endodontic plugger. Complete filling of the root canals was
checked by the extrusion of paste through the apical foramen and
reflux through the root canal opening. Post weighing of samples
was then done. .The mean weight of medicament inside the root
canal obtained was 0.215 Gms.
Apical and Coronal Sealing
The apical foramen was sealed with sticky wax to prevent any
liquid from entering the canal space and a layer of nail varnish was
applied over the sticky wax (DENTSPLY, India) to make the tooth
more impermeable, so that the diffusion of ions only occurred
through the dentin of the roots and not through the apical foramen
[9]. The medicament was compressed with a cotton ball until
there is a 2-mm space mm for the gutta-percha (DiaDent Group
International Inc, India). Using composite resin (VOCO, India),
the roots were individually attached to a metal rod fashioned from
orthodontic wire (0.7-mm thick and 5-cm long) and suspended
from rubber caps of the vials containing 30 mL of double deionised
water. (Manipal pharmaceutical products, India)
Determination of pH, Hydroxyl and calcium ions concentrations
in the solution
The readings were obtained at 24 hrs, 7 days and 14 days. The
solution was changed at each observation period to prevent super
saturation of the medium. Then, the samples were frozen at 4ºC till
the readings were taken [8].
Measurement of pH
Figure 3: Stereomicroscope
Digital pH meter
Calculation of the Hydroxyl Ion Concentration
From the data of measurement of pH in different time period in all
the groups, pOH was tabulated using the equation – [10].
pH + pOH = 14 ….. (Eq 1)
or pOH = 14 – pH ….. (Eq 2)
Once pOH was determined [OH-] i.e. Hydroxyl ion concentration
was tabulated by the reverse mathematical operation employed to
find the pOH.
[OH-] = antilog (- pOH)
or [OH-] = 10-pOH or [OH-] = 10 ^ (-pOH)
or [OH-] = 10 ^(-(14-pH)) …. (Eq 3)
Measurement of Calcium ions
Atomic absorption spectrometry (AAS, GBC 902 Australia)
(Figure 4) was employed for the determination of Ca2+
concentrations in the medium. Prior to the analysis, a reading
was performed of the double deionized water used in the study
to determine whether it contains Ca2+, thereby establishing the
baseline for the equipment. The amount of Ca2+ (µg/ml) in the
double deionized water of the samples was then determined for
subsequent analysis.
Digital pH meter (Cyberscan, Eutech Instruments Pvt Ltd,
Singapore) {Figure 3} was employed for measurement for pH.
The pH meter was calibrated with distilled water of a known pH
BAOJ Dentistry, an open access journal
Volume 3; Issue 1; 024
Citation: Sneha Sreedhar and Rashmi Nayak (2017) A Comparative Assessment of Hydroxyl and Calcium Ion Diffusion from Calcium
Hydroxide Based Intracanal Medicaments in Primary Teeth - An In Vitro Study. BAOJ Dentistry 3: 024.
Page 4 of 8
( p<0.001) at 7th day between group A and Group B with Group
C, with Group C showing lower OH values compared to other 2
groups. But at the end of the study period, the difference between
the groups was statistically non-significant.
Results
Figure 4: Atomic Absorption Spectrometer
Graph 1 shows intergroup comparison of pH across the three time
periods. On application of repeated measures of ANOVA with post
hoc Tukey test, there was highly significant differences ( p<0.001)
at 7th day between group A and Group B with Group C, with Group
C showing lower pH values compared to other 2 groups. But at
the end of the study period, the difference between the groups was
statistically non-significant.
Graph 2: shows intergroup comparison of hydroxyl ion diffusion across
the three time periods
Legend
Group A: Calcium hydroxide with distilled water
Group B: Calcium hydroxide with chlorhexidine solution
Group C Calcium hydroxide with propylene glycol in form of premixed
syringes (Diapaste)
Graph 3 shows intergroup comparison of calcium ion diffusion
across the three time periods. There was highly significant difference between group B and Group A at 24 hrs with Group A showing
lower Calcium ion values than group B. On the 7th day, there was no
statistically significant difference between the three groups (P 0.67).
Graph 1: shows intergroup comparison of pH across the three time
periods
Group A: Calcium hydroxide with distilled water
Group B: Calcium hydroxide with chlorhexidine solution
Group C Calcium hydroxide with propylene glycol in form of premixed
syringes(Diapaste)
Graph 2
Shows intergroup comparison of hydroxyl ion diffusion across
the three time periods. There was highly significant differences
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Graph 3: shows intergroup comparison of calcium ion diffusion across
the three time periods
Volume 3; Issue 1; 024
Citation: Sneha Sreedhar and Rashmi Nayak (2017) A Comparative Assessment of Hydroxyl and Calcium Ion Diffusion from Calcium
Hydroxide Based Intracanal Medicaments in Primary Teeth - An In Vitro Study. BAOJ Dentistry 3: 024.
Legend
Group A: Calcium hydroxide with distilled water
Group B: Calcium hydroxide with chlorhexidine solution
Group C Calcium hydroxide with propylene glycol in form of premixed
syringes (Diapaste)
Discussion
This study was an experimental type of in vitro study conducted in
the Department of Pedodontics and Preventive Dentistry, Manipal
College of Dental Sciences, Manipal, Karnataka, in collaboration
with National Institute of Technology, Surathkal, Karnataka and
Jawaharlal Nehru Technological University, Hyderabad
The medicament used was calcium hydroxide. Since the
introduction of Calcium hydroxide for use in dentistry by Herman
in 1920 [2] This medicament has been reported to promote healing
in many clinical situations. Calcium release and an alkaline pH
are extremely important for the biological and microbiological
performance of the material. The diffusion of calcium hydroxide
through dentinal tubules has been evaluated in several studies.
The diffusion through dentinal tubules, apical foramen, secondary
and accessory canals allows the calcium hydroxide to reach
regions contaminated by microorganisms, areas of root resorption
and surrounding tissues, promoting its antimicrobial and antiresorptive action.
It has been asserted that all biological actions of calcium hydroxide
will be progressed by the ionic dissociation of Ca2+. And OH ions
(Leonardo et al. 1982, Estrela 1997) [11, 12]. The differences in
the velocity of ionic dissociation are related directly to the vehicle
employed to obtain the paste. Our study used three vehicles distilled
water, 0.2% chlorhexidine solution and a premixed formulation
containing calcium hydroxide with propylene glycol.
Our first vehicle was distilled water. One of the most common
and easiest ways to prepare a calcium hydroxide formulation is
to mix calcium hydroxide powder with water. Advantages of this
formulation being, easier to prepare and reduced chairside time
[11].
The usefulness of mixing 0.2% chlorhexidine with Calcium
hydroxide still remains unclear and controversial (Athanassiadis
et al. 2007) [13]. Chlorhexidine is a cationic bisguanide whose
optimal antimicrobial activity is achieved within a pH range of 5.5–
7.0. It has been shown that addition of chlorhexidine digluconate
to calcium hydroxide forms calcium digluconate and a precipitate
of chlorhexidine molecules (which is not soluble). (Signoretti et al,
2011) [14]. However studies have shown that the combined use of
chlorhexidine and calcium hydroxide in the root canal generates
excessive reactive oxygen species, which explains why this mixture
shows more efficacy in eliminating endotoxin, even though non
soluble chlorhexidine precipitate is formed.(Yeung et al,2007)
[15]. However, it has also been demonstrated that the alkalinity
of Calcium hydroxide when mixed with chlorhexidine remained
unchanged [Haenni S, 2003] [16]. Chlorhexidine was considered
as one of the vehicles in our study, to assess if the combination
BAOJ Dentistry, an open access journal
Page 5 of 8
had any advantage with respect to pH, hydroxyl and calcium ion
release.
Propylene glycol is a dihydric alcohol and has been used as a vehicle
and pharmaceutical solvent in several products. Its hygroscopic
nature permits the absorption of water, which ensures a good
sustained release of calcium hydroxide for long periods. Another
advantage of this substance is its consistency, which improves the
handling qualities of the paste (Bairy et al. 1993, Simon et al. 1995)
[17, 18]
Our study used only primary molar teeth with intact root.
Numerous studies have used various samples for assessment of
diffusion of calcium and hydroxyl ions like acrylic upper incisors
(Duarte et al 2009) [19]. Human permanent maxillary and
mandibular anterior single-rooted teeth (Chamberlain et al 2009)
[20], human permanent single rooted teeth (Rehman et al 1996,
Esberard et al 1996) [21, 22] mandibular premolars (Simon et al,
1995) [18]. Permanent canines (Minana et al, 2001) [23], singlerooted bovine roots (Camargo, 2006) [24] mixture of single and
multiple root canals of deciduous teeth (Nunes et al, 2005) [25]
polyethylene tubes (Fulzele, Baliga et al 2011) [26]. The study
conducted by Ximenes et al 2012 [8], used the primary molar teeth
for assessment of both calcium and hydroxyl ion diffusion.
In primary molar teeth, furcal radiolucency is commonly seen
unlike primary anterior teeth where radiolucency is seen at
the periapical region. Therefore, to assess the lateral diffusion
of intracanal medicament along the dentinal tubules, it was
imperative to collect primary molar teeth without any resorption,
perforation or surface defect. To rule out perforation/ resorption,
a high precision instrument i.e. stereomicroscope has been used
.The advantages of stereomicroscope over the traditional ones
being great working distance and depth of field thereby reducing
the chance of human error.
In the present study, the coronal portion of the tooth sample was
sectioned transversely 2mm above the CEJ to obtain a coronal seal
which more closely simulates a clinical scenario thereby ensuring
that medicament penetration occurred only through the radicular
dentine. Also the samples were suspended till the level of CEJ in
the deionized water so the diffusion of ions through the radicular
dentin was assessed. Which is according to study conducted by
Ximenes et al 2012[8].
It is suggested that the removal of the smear layer may facilitate
the diffusion of hydroxyl ions through the dentinal tubules and
improve the ability to kill bacteria [27].The removal of the smear
layer from the interior of the root canal also facilitates the diffusion
of ions through the dentin tubules, thereby enhancing the action of
the medication (Mori et al,2009; Foster et al,1993; Garcia-Godoy
,1987) [27,28,29].Therefore in the present study, prior to using an
intracanal Calcium hydroxide based medication, irrigation was
performed with 1 % sodium hypochlorite and 17% EDTA for 3
minutes to allow greater action of the medication. The samples
were there afterwards washed with saline to prevent any residual
chelating action of EDTA. (Saif et al, 2008) [30].
Volume 3; Issue 1; 024
Citation: Sneha Sreedhar and Rashmi Nayak (2017) A Comparative Assessment of Hydroxyl and Calcium Ion Diffusion from Calcium
Hydroxide Based Intracanal Medicaments in Primary Teeth - An In Vitro Study. BAOJ Dentistry 3: 024.
In our study, the root apex was sealed with sticky wax and nail
varnish for greater impermeability (Nunes et al, 2005) [9] and
coronally with guttapercha and composite (Ximenes et al 2012)
[8] to the ensure that the diffusion of ions occurred only through
radicular dentin.
The diffusion of ions is dependent on the volume of the medicament
in the canal. Keeping all other factors (the vehicle, length and
diameter of dentinal tubule) constant, it was hypothesized that
the more the volume, more will be the diffusion. Therefore,
standardization was done at every step of the study in terms of ratio
of powder and liquid, weight of medicament, and the biomechanical
preparation hence minimizing the possibility of bias.
For the assessment of OH- and Ca2+ diffusion, the roots remained
immersed in double deionized water for the time periods
established (24 hours, 7 days, and 14 days,).Double deionised
water is ultrapure water free of ions like Mg+2, Ca2+,Na+,Cl- which
can interfere with readings of the three variables.(pH,hydroxyl and
calcium ions), thereby reducing the confounding factors and error
[31].Unlike in previous studies, (Nerwich et al,1993; Simon et al,
1995; Nunes et al,2005) [4]. the double deionised water in which
the roots were immersed was replaced on every measurement day
to obtain the maximum diffusion of ions without saturating the
medium .The samples were frozen at 4 degrees Celsius till analysis.
It was in accordance to the study done by Ximenes et al, 2012[8].
We have assessed the diffusion of ions at 24hrs, 7 days and 14 days
.The period needed for calcium hydroxide to optimally disinfect
the root canal system is still unknown. Bystrom et al in 1985 [32].
demonstrated that calcium hydroxide effectively eliminated all
the microorganisms when the medicament was maintained for
4 weeks However, Jorgen et al in 1991[33] have reported that an
intracanal medication with calcium hydroxide for 1 week effectively
eliminated bacteria in the root canal in 100% of the cases. In a
clinical situation, since the obturating material in the primary teeth
is stronglyantibactericidal and it was assumed that an intermediate
dressing of 14 days could be employed. .So, a period of 14 days was
chosen in our study. Also, a change of dressing was not performed
between the time periods.
Atomic absorption spectrometer was used to determine Ca2+
ion concentration. It makes use of absorption spectrometry to
assess the concentration of an analyte in a sample. It requires
standards with known analyte content to establish the relation
between the measured absorbance and the analyte concentration
.It can detect the concentrations of analyteupto as low as 0.1ppm.
Unlike colorimetric method, the chances of human error and
contamination is almost nil [34].
In the present study, all three formulations of calcium hydroxide
facilitated a gradual increase in pH of the solution above neutral
pH but at the same time did not show a large rise either. There
may be various explanations for this marginal rise of pH. Primary
molar teeth with ribbon shaped canals do not accommodate as
much medicament as in permanent tooth. In our present study, the
cementum was left intact on the root surface and the two ends of
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Page 6 of 8
the specimen were sealed. However, in a clinical scenario, presence
of open apical foramina, areas of resorption and cementum loss
may result in greater rise of pH. Also, in this study the primary
molar teeth were sectioned and each root was considered as one
sample. But in clinical situations, the multirooted teeth when filled
with medicament may result in a greater diffusion of ions into
periapical region.
The minimal amount of hydroxyl ions capable of making a medium
unviable for bacterial proliferation by neutralizing the acid
environment remains unknown. However, as seen by the results
of the present study the medium into which the specimens were
suspended showed a steady rise in towards alkaline pH signifying
that ionic release takes place through dentin of primary roots.
These results are in accordance with Nerwich et al,1999 [4] who
reported that hydroxyl ions required 1-7 days to reach the outer
root dentine and 2-3 weeks to reach peak levels. All agents showed
peak pH and hydroxyl ion concentration at 7 days.
Although combining calcium hydroxide and chlorhexidine has
been viewed skeptically, the results of this study show it was capable
of raising the pH of the solution comparable to distilled water and
this result is accordance to that reported by Haenni S,2003[16] that
pH remained unchanged on combination with chlorhexidine.
With respect to calcium release, the greatest release was demonstrated by Calcium hydroxide with propylene glycol followed by
calcium hydroxide and distilled water.
Calcium hydroxide with chlorhexidine performed poorly when
compared to other two groups, in terms of the calcium ion release.
It was observed that there was an initial burst of calcium ion
followed by steep decrease to negligible amount (1.51µg/ml) at
end of study period. It has been reported that Calcium hydroxide
when mixed with chlorhexidine forms calcium digluconate and a
precipitate of chlorhexidine [14]. In our study, the medicament was
freshly mixed just prior to obturation of each sample and the roots
were suspended in double deionized distilled water immediately
following obturation. Hence it can be assumed that the initial burst
was due to the unbound calcium ions present in the medium and the
steep decrease of diffusion was due to decreased calcium available
for diffusion following the formation of calcium digluconate.The
nature and chemistry of calcium digluconate is still unclear and
needs further investigation.
Overall, the results of this study confirmed to findings reported in
literature that distilled water vehicle shows faster ionic dissociation
and viscous vehicles cause slow, constant and prolonged release of
ions Based on results of our study, the null hypothesis was rejected.
The limitation of the present study is that, in vivo conditions were
not simulated. The presence of the open apex (which was closed
in this study) which is also responsible for diffusion of ions to
periapical region, the presence of physiologic and pathologic root
resorption (present in most endodontic treatment cases) and the
presence of an inflammatory process which reduces the external
pH around the root all affect the action of intracanal medicaments.
Volume 3; Issue 1; 024
Citation: Sneha Sreedhar and Rashmi Nayak (2017) A Comparative Assessment of Hydroxyl and Calcium Ion Diffusion from Calcium
Hydroxide Based Intracanal Medicaments in Primary Teeth - An In Vitro Study. BAOJ Dentistry 3: 024.
Therefore more in-vitro studies with larger sample size need to be
conducted with simulated in vivo conditions.
Why This Study Is Important To Pediatric Dentists
• This study has shown that hydroxyl and calcium ions from the
different formulations of calcium hydroxide diffused through
the dentin and cementum of the roots of primary teeth
• This study has shown that peak concentrations for pH, Hydroxyl
ion observed at 14 days in all three groups.
Page 7 of 8
15.Yeung SY, Huang CS, Chan CP, Lin CP, Lin HN, et al. (2007) Antioxidant
and pro-oxidant properties of chlorhexidine and its interaction with
calcium hydroxide solutions. 40(11): 837-844.
16.HaenniS, Schmidlin P R, MuellerB, SenerB, Zehnder M (2003) Chemical and antimicrobial properties of calcium hydroxide mixed with irrigating solutions. 36(2): 100-105
17.Bairy I, Bhat KS, Shivananda PG (1993) An in vitro evaluation of antibacterial action of calcium hydroxide against causative organisms of
osteomyelits. 11(4): 238-242.
• .With given parameters, the vehicle of propylene glycol
performed the best in length and duration of action while the
distilled water vehicle caused rapid ionic release. Therefore in
cases where patient follow up is difficult, the vehicle of oil can
be preferred.
18.Simon S T, Bhat K S, Francis R (1995) Effect of four vehicles on the pH
of calcium hydroxide and the release of calcium ion. Oral Surg 80(4):
459-464.
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Citation: Sneha Sreedhar and Rashmi Nayak (2017) A Comparative Assessment of Hydroxyl and Calcium Ion Diffusion from Calcium
Hydroxide Based Intracanal Medicaments in Primary Teeth - An In Vitro Study. BAOJ Dentistry 3: 024.
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