The Effect of Apple Vinegar as an Irrigation Solution to Dental Root

Canal Microstructure

Rudy Djuanda

, Eliza Madyanty

, Almira Anggarini Witjaksono

Vinna Kurniawati Sugiaman

and Natallia Pranata

Department of Restorative Dentistry, Faculty of Dentistry, Maranatha Christian University, Jalan Prof. Suria Sumantri,

Bandung, Indonesia

Faculty of Dentistry, Maranatha Christian University, Bandung, Indonesia

Department of Oral Biology, Faculty of Dentistry, Maranatha Christian University, Bandung, Indonesia

Keywords: Irrigation, Apple Vinegar, SEM, Microstructure, Erosion, Smear Layer.

Abstract: NaOCl and EDTA are the standard of irrigation solutions. However, long-term use can cause unwanted

effects. Apple vinegar is acidic so it can cause demineralization. This research was conducted to determine

the effect of apple vinegar as an irrigation solution on the dentin microstructure of the root canals. This

research is a laboratory experiment with a posttest only control group design. 24 post-extraction mandibular

premolars were divided based on the irrigation solution used, namely 2.5% NaOCl, 100%, 75%, 75%, 25%,

12.5%, 6.25% apple vinegar, and aquadest. The microstructural changes observed with the Scanning Electron

Microscope at 2000 magnification. The assessment of cleanliness used the Hulsmann scoring while the

erosion was used the criteria of Torabinejad. The cleanliness in the positive control had an average score of

1. The 100% apple vinegar solution group had a score of 1.67. In the lower apple vinegar concentration group

had a greater average score. The average dentin erosion scores of each group were compared with the positive

control with p-value ≥ 0.05. Apple vinegar as an irrigation solution affects the dentin microstructure of the

root canal. There was no erosion, but the cleanliness of the smear layer increased according to the increase of

concentration.

1 INTRODUCTION

Root canal treatment is influenced by

chemomechanical thorough debridement of the pulp

tissue, dentine debris, and microorganisms. Root

canal irrigation solution used during root canal

treatment provides chemical and mechanical effects.

Chemical debridement is indispensable to remove

smear layers, especially on teeth with complex

internal anatomy or other irregularities that may have

been missed by instrumentation during mechanical

debridement. The mechanical effect of irrigation is

produced by the flow of the irrigation solution during

the cleaning and formation of root canals. Irrigation

solution can remove debris, dissolving tissues, and

disinfect the root canal system. Bacteria are a major

etiological factor in the development of pulp and

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periapical lesions. Research shows that the irrigation

solution which has antibacterial properties have better

effectiveness.(Borzini et al., 2016; Kirchhoff et al.,

2014)

The most effective time to irrigate a root canal is

40 minutes. Ethylene Diamine Tetraacetic Acid

(EDTA) and Sodium Hypochlorite (NaOCl) are

irrigation solutions widely used in endodontics.

Long-term use of EDTA and NaOCl at high

concentrations can cause undesirable effects on the

root canal wall, such as flexural strength,

microhardness, root canal dentin roughness, and

significantly reduced elastic modulus. EDTA is used

most as a 17% neutralized solution. The EDTA

solution reacts with calcium ions in the dentin to form

soluble calcium chelates. The pH of the EDTA

solution is an important factor that affects the

126

Djuanda, R., Madyanty, E., Witjaksono, A., Sugiaman, V. and Pranata, N.

The Effect of Apple Vinegar as an Irrigation Solution to Dental Root Canal Microstructure.

DOI: 10.5220/0010745900003113

In Proceedings of the 1st International Conference on Emerging Issues in Technology, Engineering and Science (ICE-TES 2021), pages 126-130

ISBN: 978-989-758-601-9

cleaning of the root canal walls. NaOCl served as a

disinfectant that was widely used in the late 19th

century. Organic tissue can react with NaOCl,

resulting in saponification, neutralization of amino

acids, and can also dissolve necrotic tissue. NaOCl

solution is more ideal than other irrigation

solutions.(Kaya et al., 2011; Calaletin Topbas &

Adiguzel, 2017)

Apple vinegar is made from crushed and extracted

apples. Acetobacter bacteria and yeast are added to

start the fermentation process. At the beginning of the

process, sugar is converted to alcohol and then

alcohol is converted into vinegar. The acetic and

malic acids in vinegar cause a sour taste and low pH.

Apple cider vinegar also contains vitamins B1, B2,

B3, B5, B6, B7, B9, pectin, flavonoids, polyphenols,

and minerals.(Mohanty et al., 2017; Nazni et al.,

2015) In traditional medicine believed apple vinegar

has an antibacterial effect. Several studies have

examined the bactericidal activity and bacteriostatic.

This activity depends on the concentration of acetic

acid, incubation time, number of bacteria, and

temperature.(Kalaba et al., 2019; Ulbricht & Basch,

2016) Acidic conditions can cause the demineralized

dentin.(Kaya et al., 2011; Omar et al., 2016)

Demineralization will cause changes in the dentin

microstructure. It is necessary to investigate the

influence of the dentin microstructure if apple vinegar

is used as an irrigation solution.

2 METHODS (AND MATERIALS)

This is experimental laboratory research with a

posttest only control group design. The 24 post-

extraction of mandibular premolars were planted in

wax blocks. The tooth was prepared for the root

canals treatment using the crowndown technique.

These samples were divided into 8 groups. Each

group was given a different irrigation solution. Group

I is a positive control will be given 2.5% NaOCl

solution. Groups II to VII are the test group. Various

concentrations of apple vinegar will be used as an

irrigation solution. Group II will be given a 100%

apple vinegar solution, group III 75% apple vinegar,

group IV apple vinegar 50%, group V apple vinegar

25%, group VI 12.5%, and group VII 6.25%. Group

VIII is a negative control, using aquadest as the

irrigation solution. The groups can be seen in Figure

Figure 1: Group category of irrigation solution.

Samples after being treated, the split into 2 halves

using a diamond disk and chisel. The apical part was

placed on the metal stub, then coated with Pd Au to

make it more conductive at the time of observation.

The dentin microstructure was observed using a

Scanning Electron Microscope (SEM). Taking

pictures of the specimen chamber was done with a

2000 magnification. Dentin microstructural changes

observed by the cleanliness and erosion in one-third

of the root canal. Cleanliness is determined by the

presence of a smear layer and the percentage of

visible dentinal tubules. The guidelines used are

based on the Hulsmann scoring system.(Mancini et

al., 2021) Score 1: there is no smear layer and dentinal

tubules clearly visible. Score 2: There was a small

amount of smear layer and more than 50% open

dentinal tubules. Score 3: There is a smear layer

almost along the wall of the root canal and dentinal

tubules are less than 50% open. Score 4: The entire

root canal wall was covered by a smear layer and the

dentinal tubules were not clearly visible. The average

scoring is then analyzed statistically by non-

parametric test Kruskal-Mann continued Whiteney.

The observations of the erosion score for each

group was classified according to the criteria of

Torabinejad et al. (Görduysus et al., 2015;

Torabinejad et al., 2003) Score 0: the smear layer

covers almost all the surface of the dentin, little or no

open at all. Score 1: no erosion: all tubules appear

normal. Score 2: moderate erosion: eroded

peritubular dentin. Score 3: severe erosion: the

intertubular dentin is crushed and the tubules are

connected to each other. ANOVA analysis was used

to compare the erosion scores between groups.

3 RESULTS AND DISCUSSION

SEM images in each group are represented by Figure

2-5. Microstructural changes in each group were

observed and categorized based on scoring.

The Effect of Apple Vinegar as an Irrigation Solution to Dental Root Canal Microstructure

127

A. Group I, positive control, used 2.5% NaOCl irrigation

solution, there was no smear layer, no erosion, the dentinal

tubules were clear and normal.

B. Group VIII, negative control, using aquadest, the entire root

canal wall was covered by a smear layer.

Figure 2: SEM images (original magnification of ×2000) of

representative specimens of group I (A), and group VIII

(B).

A. Group II, using 100% apple vinegar irrigation solution, no

smear layer, no erosion, most of the dentin tubules were open.

B. Group III, using 75% apple vinegar irrigation solution, there

was a small amount of smear layer, no erosion, the dentinal

tubules looked normal and more than 50% open.

Figure 3: SEM images (original magnification of ×2000) of

representative specimens of group II (A), and group III (B).

A. Group IV, using a 50% apple vinegar irrigation solution.

B. Group V, using a 25% apple vinegar irrigation solution.

In both groups, there was a small number of smear layers, no

erosion, the dentinal tubules were normal and less than 50%

open.

Figure 4: SEM images (original magnification of ×2000) of

representative specimens of group IV (A), and group V (B).

A. Group VI, using 12.5% apple vinegar irrigation solution.

B. Group VII, using 6.25% apple vinegar irrigation solution.

In both groups, there was a small number of smear layers, no

erosion, the dentinal tubules were normal and less than 50%

open.

Figure 5: SEM images (original magnification of ×2000) of

representative specimens of group VI (A), and group VII

(B).

Cleanliness of the root canal dentin, which is

determined by the presence of smear layer and dentin

tubules visibility, an average score of 1, in the

positive control group, 2.5% NaOCl irrigation

solution. Group II, 100% apple vinegar irrigation

solution, had an average score of 1.67. The smaller

concentration of apple vinegar, the greater the scoring

average. The average scoring in each group can be

seen in Figure 6.

Figure 6: The average score cleanliness of dentin.

The cleanliness smear layer of apple vinegar with

100% concentration had no significant results with

positive control. The group of 100% apple vinegar

has the same effect as good as 2.5% NaOCl solution.

The cleanliness smear layer increased accordingly

increased the concentration of apple vinegar.

Erosion microstructure of each group after

observed then made the average, as seen in Table 1.

The average value highest in the positive control

group was 1.42. These data indicate that there is no

erosion and dentinal tubules are seen as normal in all

test groups.

ICE-TES 2021 - International Conference on Emerging Issues in Technology, Engineering, and Science

128

Table 1: The average score of dentin microstructure

erosion.

Test Groups

Average

Score

NaOCl

2.5%

Significan

II. Apple vinegar 100% 0,81

1,43

0,858

III. Apple vinegar 75% 0,83 0,257

IV. Apple vinegar 50% 1,08 1,858

V. Apple vinegar 25% 0,75 0,139

VI. Apple vinegar 12,5% 1,42* 0,999*

VII. Apple vinegar 6,25% 0,83 0,257

*Indicates the concentration of apple vinegar, whose erosion is

close to NaOCl

The average score after analyzed statistically, a

significant difference between groups, with p-value ≥

0.05. The test group that had a significance value

close to NaCl was the 75% apple vinegar group.

The irrigation solution in endodontic treatment

has a very important role, such as an antibacterial,

lubricating the dentin walls, dissolving the smear

layer, and increasing the sealer bonding

ability.(Pereira et al., 2012; Calaletin Topbas &

Adiguzel, 2017) The use of apple vinegar as an

irrigation solution in root canal treatment has good

potential.(Kirchhoff et al., 2014) The results of this

study are in line with several previous studies

regarding changes in dentin microstructure caused by

irrigation solutions.(Borzini et al., 2016; Celalettin

Topbas & Adiguzel, 2017) The cleanliness and dentin

erosion using apple vinegar irrigation solution is

similar to NaOCl.

Previous research has found that apple vinegar

contains citric, malic, and lactic acids.(Kirchhoff et

al., 2014; Mohammadi et al., 2017) Citric acid is a

weak organic acid having the molecular formula

in the form of a white crystalline powder at

room temperature, in anhydrous or monohydrate

form. Citric acid has an antibacterial effect.(Dewi et

al., 2020)

Citric acid can lower the pH and further suppress

the oxidation of nicotinamide adenine dinucleotide

(NADH), which resulted in the death of bacteria.

Citric acid change the local pH environment that can

prevent the absorption of essential nutrients by

microorganisms because of the permeability of cell

walls which in turn cause damage and cell death,

particularly in gram-negative bacteria.(Dewi et al.,

2020; Kirchhoff et al., 2014; Mohammadi et al.,

2017)

Citric acid also could remove the smear layer. The

removal of the smear layer occurs by forming a

complex bond (chelate) with the calcium content

contained in the inorganic debris of the smear layer.

Citric acid is also known as dentin conditioning, its

dentine conditioning properties can dissolve dentin

hydroxyapatite so that the collagen fibril tissue will

open. Citric acid is 10% better than ultrasound

irrigations for removing the smear layer from the root

apex.(Gutmann et al., 1994)

Apart from citric acid, malic acid with the

molecular formula C

is the main acid found in

many fruits, including apples, apricots, blackberries,

blueberries, cherries, grapes, mirabella, peaches,

pears, and plums which were first obtained from

apple juice by Carl. Wilhelm Scheele in

1785.(Setyawati & Nur, 2020)

Malic acid is a carboxylic acid group that could

whiten teeth by oxidizing the surface of the tooth

enamel to become neutral and causing a whitening

effect. Malic acid has a very low molecular weight so

that it can diffuse into enamel and dentin, and can

oxidize the surface of tooth enamel by releasing

oxygen-free in the double bonds of organic and

inorganic compounds in teeth.(Kirchhoff et al., 2014)

Lactic acid with the molecular formula

CHOHCOOH is often associated with dental

caries. The use of lactic acid with a concentration of

20% applied for 10 seconds will produce a

demineralized surface, while at a concentration of

30% it will remove the smear layer, increase the

diameter of the dentinal tubules, and affect the

collagen matrix (Kirchhoff et al., 2014).

4 CONCLUSIONS

Apple vinegar as an irrigation solution affects the

dentin microstructure of the root canals. There was no

erosion, but the cleanliness of the smear layer

increased according to the increase in the

concentration of apple vinegar.

ACKNOWLEDGEMENTS

We thank Faculty of Dentistry of Maranatha Christian

University for the technical support during the

research. This research received grant from

Maranatha Christian University.

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