Haewon Lee

5th year, group 14

Effect of various residual adhesive removal methods

on enamel surface after bracket debonding:

a Systematic Review

Master’s Thesis

Supervisor

PhD, Julija Urbonė

Kaunas, 2018

LITHUANIAN UNIVERSITY OF HEALTH SCIENCES

MEDICAL ACADEMY

ODONTOLOGY FACULTY

THE CLINIC OF ORTHODONTICS

Effect of various residual adhesive removal methods

on enamel surface after bracket debonding:

a Systematic Review

Master’s Thesis

The thesis was done

by student ................................................ Supervisor ............................................... (signature) (signature)

.....................................................

..........................................................................

... (name surname, year, group) (degree, name surname)

.............................. 20…. .............................. 20….

(day/month) (day/month)

Kaunas, 2018

EVALUATION TABLE OF THE MASTER’S THESIS

OF THE TYPE OF SYSTEMIC REVIEW OF SCIENTIFIC LITERATURE

Evaluation: ...............................................................................................................................

Reviewer: .................................................................................................................................. (scientific degree. name and surname)

Reviewing date: ...........................................

No.

MT parts

MT evaluation aspects

Compliance with MT

requirements

and evaluation

Yes Partially No

1

Summary

(0.5 point)

Is summary informative and in compliance with the thesis content and requirements?

0.3 0.1 0

2 Are keywords in compliance with the thesis essence?

0.2 0.1 0

3 Introduc-

tion, aim

and tasks

(1 point)

Are the novelty, relevance and significance of the work justified in the introduction of the thesis?

0.4 0.2 0

4 Are the problem, hypothesis, aim and tasks formed clearly and properly?

0.4 0.2 0

5 Are the aim and tasks interrelated? 0.2 0.1 0

6

Selection

criteria of

the studies,

search

methods and

strategy

(3.4 points)

Is the protocol of systemic review present? 0.6 0.3 0

7 Were the eligibility criteria of articles for the

selected protocol determined (e.g., year,

language, publication condition, etc.)

0.4

0.2

0

8

Are all the information sources (databases with

dates of coverage, contact with study authors to

identify additional studies) described and is the

last search day indicated?

0.2

0.1

0

9

Is the electronic search strategy described in such

a way that it could be repeated (year of search, the

last search day; keywords and their combinations;

number of found and selected articles according

to the combinations of keywords)?

0.4

0.1

0

10

Is the selection process of studies (screening,

eligibility, included in systemic review or, if

applicable, included in the meta-analysis)

described?

0.4

0.2

0

11

Is the data extraction method from the articles

(types of investigations, participants,

interventions, analysed factors, indexes)

described?

0.4

0.2

0

12

Are all the variables (for which data were sought

and any assumptions and simplifications made)

listed and defined?

0.4

0.2

0

13

Are the methods, which were used to evaluate the risk of bias of individual studies and how this information is to be used in data synthesis, described?

0.2

0.1

0

14

Were the principal summary measures (risk ratio, difference in means) stated?

0.4 0.2 0

15

Systemiza

- tion and

analysis of

data

(2.2

points)

Is the number of studies screened: included upon

assessment for eligibility and excluded upon

giving the reasons in each stage of exclusion

presented?

0.6

0.3

0

16

Are the characteristics of studies presented in the

included articles, according to which the data were

extracted (e.g., study size, follow-up period, type

of respondents) presented?

0.6

0.3

0

17

Are the evaluations of beneficial or harmful

outcomes for each study presented? (a) simple

summary data for each intervention group; b)

effect estimates and confidence intervals)

0.4

0.2

0

18 Are the extracted and systemized data from studies

presented in the tables according to individual tasks?

0.6

0.3

0

19

Discussio

n (1.4

points)

Are the main findings summarized and is their relevance indicated?

0.4 0.2 0

20 Are the limitations of the performed systemic review discussed?

0.4 0.2 0

21 Does author present the interpretation of the results?

0.4 0.2 0

22

Conclusion

s (0.5

points)

Do the conclusions reflect the topic, aim and tasks of the Master’s thesis?

0.2 0.1 0

23 Are the conclusions based on the analysed material?

0.2 0.1 0

24 Are the conclusions clear and laconic? 0.1 0.1 0

25

Reference

s (1

point)

Is the references list formed according to the requirements?

0.4 0.2 0

26

Are the links of the references to the text correct?

Are the literature sources cited correctly and

precisely?

0.2

0.1

0

27 Is the scientific level of references suitable for Master’s thesis?

0.2 0.1 0

28

Do the cited sources not older than 10 years old

form at least 70% of sources, and the not older

than 5 years – at least 40%?

0.2

0.1

0

Additional sections, which may increase the collected number of points

29 Annexes Do the presented annexes help to understand the analysed topic?

+0.2 +0.1 0

*Remark: the amount of collected points may exceed 10 points.

30

Practical

recomme

ndations

Are the practical recommendations suggested

and are they related to the received results?

+0.4

+0.2

0

31

Were additional methods of data analysis and their

results used and described (sensitivity analyses, meta-regression)?

+1

+0.5

0

32

Was meta-analysis applied? Are the

selected statistical methods indicated? Are

the results of each meta-analysis presented?

+2

+1

0

General requirements, non-compliance with which reduce the number of points

33

Gener

al

requir

ements

Is the thesis volume sufficient (excluding

annexes)?

15-20 pages (-2 points)

<15 pages (-5 points)

34 Is the thesis volume increased artificially?

-2 points -1 point

35 Does the thesis structure satisfy the requirements of Master’s thesis?

-1 point -2 points

36 Is the thesis written in correct language, scientifically, logically and laconically?

-0.5 point -1 points

37 Are there any grammatical, style or computer literacy-related mistakes?

-2 points -1 points

38 Is text consistent, integral, and are the volumes of its structural parts balanced?

-0.2 point -0.5 points

39 Amount of plagiarism in the thesis. >20% (not evaluated)

40

Is the content (names of sections and

sub- sections and enumeration of pages)

in compliance with the thesis structure

and aims?

-0.2 point

-0.5 points

41

Are the names of the thesis parts in

compliance with the text? Are the titles

of sections and sub-sections

distinguished logically and correctly?

-0.2 point

-0.5 points

42 Are there explanations of the key terms and abbreviations (if needed)?

-0.2 point -0.5 points

43

Is the quality of the thesis typography

(quality of printing, visual aids, binding)

good?

-0.2 point

-0.5 points

*In total (maximum 10 points):

Reviewer’s comments: _____________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

Reviewer’s name and surname Reviewer’s signature

０

TABLE OF CONTENTS

SUMMARY...................................................................................................................... 1

INTRODUCTION............................................................................................................ 2

SELECTION CRITERIA OF THE STUDIES. SEARCH METHODS AND

STRATEGY...................................................................................................................... 4

1 SYSTEMATIZATION AND ANALYSIS OF DATA................................................... 8

1.1 Study characteristics......................................................................................................... 11

DISCUSSION................................................................................................................... 18

CONCLUSIONS.............................................................................................................. 20

REFERENCES................................................................................................................. 21

１

SUMMARY

Objectives: The purpose of the present study is (1) to assess the effect of adhesive removal method

on enamel surface and (2) recommend the best method for adhesive remnant clean up.

Material and Methods: In this systematic review, identification of relevant literature has been

proceeded by PubMed and ScienceDirect electronic databases which searched the data published

from 1st of February 2008 up to 28th of February 2018 with these searching keywords: Orthodontic

brackets, debonding, adhesive removal, enamel surface, enamel damage.

Results: A total 193 scientific articles were identified which were related to keywords. Finally, 10

articles were selected. The present data included 454 extracted teeth that majority of them are

premolars. No meta-analysis could be performed due to the heterogeneity of quantitative result which

caused by different enamel surface assessment instruments Our tasks are to review and to analyze

efficiency of available adhesive removal methods on extracted human teeth to minimize enamel

damage after debonding fixed appliance. The result in the present systematic review shows that the

most destructive tools are diamond bur, ultrasonic scaler, adhesive removing plier, and laser which

cause irreversible iatrogenic damage on enamel. In all studies showed that tungsten carbide burs are

faster but produced rougher enamel surface especially at high speed than the other methods mentioned

in this study.

Conclusions: Sof-Lex disk, composite bur, fiberglass bur, glass air-abrasion, adhesive residue

remover and one step finisher and polisher shown remarkable less enamel surface roughness than

tungsten carbide bur but taken longer time for adhesive remnant removal. So that, considered in the

aspects of enamel damage, required time for adhesive removal and cost, a combination of methods

could be recommended. Further studies should be performed to find out adhesive removal method

for perfect adhesive clean up and combination among them which can minimize enamel loss and gain

a smooth surface.

Keywords: Orthodontic brackets, debonding, adhesive removal, enamel surface, enamel damage

２

INTRODUCTION

At the end of the orthodontic treatment with a fixed appliance, the last important task is to turn the

enamel surface back to its original condition with minimal enamel loss and to return its original

roughness by removing the bonded brackets and residual adhesive [1,2].

Enamel loss has been investigated using methods which can be classified as qualitative, semi-

quantitative or quantitative. Qualitative methods such as scanning electron microscopy consist of

subjective observations of surfaces following debonding. Semi-quantitative methods are similar but

make use of an index for measurement. Quantitative methods can measure the actual depth of

removed enamel surface, spot, line, the surface rugosity or the mean depth of enamel loss by analysis

of a three dimensional (3D) scan of the resultant surface. Quantitative methods can be surface

roughness tester, profilometry, laser scanning devices, atomic force microscope and optical coherence

tomography. Scanning electron microscopy requires subjective inspection, and cannot be used for

comparative assessments alone. Alternatively, quantitative techniques can provide more reliable

comparisons of different cleanup processes [1,3-5].

To restore enamel surface after orthodontic treatment requires two main steps, bracket debonding and

clearing the residual adhesive from the tooth surface. The first step is brackets removing, various

methods are using such as mechanical methods, chemical solvents, ultrasonic scalers and, lasers. The

mechanical removal method is universally used in clinical practice among those methods and

different bracket debonding forces are used in combination with mechanical removal methods.

Following procedure is removing adhesive resin, many researchers have introduced different

techniques for resin removal and subsequent enamel polishing without causing iatrogenic damage

[1,6]. So far, to obtain clear enamel appearance after debracketing, diverse tools have been proposed

to remove adhesive remnants such as various burs, Sof-Lex discs, ultrasonic devices and air abrasion

units. Although there are different opinions in the literature regarding this matter,tungsten carbide bur

at low speed is one of the most common and conventional methods of removing residual adhesive

from the enamel surface. Nowadays various new and more conservative multiple and one-step

systems for cleaning enamel surface have been developed and gained popularity among orthodontists

[6,7].

３

Apparently, the effect of the mechanical removal of remaining adhesives after bracket debonding

seemed destructive to enamel surface, causing a significant amount of enamel loss and irreversible

enamel damage. Although scarring on the enamel surface during adhesive removal can’t be avoided,

the damage can be significantly reduced if selecting a proper technique. Therefore, there is a great

need for choosing effective removal techniques to cause the least damages to the patient at the end of

treatment and, whenever possible, preserve the original tooth condition [6,7].

This study aimed to determine the most efficient method for removing adhesive remnant on enamel

surface after bracket debonding which causes the least damage to enamel and to suggest a proper

method.

Our tasks are to review and to analyze efficiency of available adhesive removal methods on extracted

human teeth to minimize enamel damage after debonding fixed appliance.

4

SELECTION CRITERIA OF THE STUDIES.

SEARCH METHODS AND STRATEGY

This systematic review was organized according to the protocol of the following PRISMA (Preferred

Reporting Items for Systematic Reviews and Meta-analysis) guidelines [8].

The search for relevant articles was conducted by PubMed/MEDLINE and ScienceDirect electronic

databases. The Key terms that were used in the search are: “orthodontic brackets,” “debonding,”

“adhesive removal,” “enamel surface” and “enamel damage.”

The Studies included evaluation of articles from dental journals which published between 1st of

February 2008 and 28th of February 2018 in English language, able to read in full version and studies

were specified into performed only on human category with the keywords that were selected.

Total 193 publications were identified, titles and abstracts of all the studies were screened impartially

without bias about the names of the authors or the publication dates and finally, full reports were

obtained for all the studies that were deemed eligible for inclusion in this paper (Figure 1).

Data was collected independently extracted from reports in the form of variables according to the aim

and themes of present review as listed on words. The following data were obtained from the included

articles: Author(s), year of publication, investigated extracted teeth, adhesive removal, enamel surface

assessment method, quantitative analysis, qualitative analysis.

In this systematic review, the focus question was advanced according to population, intervention,

comparison, and outcome(PICO) (Table 1).

Table 1. PICO question table

Population (P) Extracted teeth which underwent bracket attachment with adhesive materials

and then debonding process.

Intervention (I) Various adhesive removal methods.

Comparison(C) Comparison of mechanical effect on enamel surface.

5

Outcome (O) Comparing the difference in enamel roughness or enamel loss depends on

adhesive removal method by quantitative and qualitative analysis.

Focus question What kind of method is the most efficient to remove adhesive remnant on

enamel surface with leading the least damage to enamel and can be suggested?

The resulting articles were independently subjected to clarify inclusion and exclusion criteria.

Inclusion and exclusion criteria

Inclusion criteria for the selection were;

• Comparison between at least 2 of adhesive removal or polishing methods.

• In vitro studies in measuring enamel damage.

• Studies with metal brackets or buccal metal tubes.

• Studies about remineralized, demineralized enamel were included only if experiments on

sound enamel were carried out under same intervention.

• Studies include tungsten carbide bur as a comparator.

Exclusion criteria for the selection were:

• Non-human studies.

• Studies which is showing single case reports, literature reviews, commentaries.

• Studies with ceramic brackets.

• Assessing and evaluating the enamel surface only by qualitative or semi-quantitative

methods.

• Studies does not include tungsten carbide burs as a comparator.

• Studies compare polishing methods after using only one adhesive removal method.

6

Risk of bias assessment

The risk of bias was included in the extraction procedure with The Cochrane Risk of Bias Tool [9]

that include six processes: Random sequence generation, allocation concealment, blinding of

participant’s and personnel, blinding of outcomes assessment, incomplete outcome data selective

reporting, other bias. The risk of bias that indicated within these studies is collected and organized in

Table 2.

Risk of bias quality assessment within studies

The quality assessment of the selected articles showed an unknown risk of bias for all of the included

articles because they were unclearly described and high risk of other bias in most of the articles

because the population of studies was controlled.

Synthesis of results

Relevant data of interest on the previously stated variables (Author, year of publication, investigated

extracted teeth, and adhesive removal, enamel surface assessment method, outcome) were collected

and organized into a table 3 and 4.

Statistical analysis

No meta-analysis could be performed due to the heterogeneity between studies. Various assessment

methods and outcome variables are made it difficult to establish a comparison between the studies.

Parametric data were expressed as mean enamel loss or enamel surface roughness.

7

Table 2. Risk of bias assessment

Study Random

sequence

generation

Allocation

conceal-

ment

Blinding

of

participa

nt’s and

personnel

Blinding of

outcomes

assessment

Incompl

ete

outcome

data

Selective

reporting

Oth

er

bias

Banerje

e et al.

[4]

? ? + + + + -

Sigilião

et al.

[6]

? ? + + + + -

Ahrari

et al.

[7]

? ? + + + + -

Taha et

al. [10]

? ? + + + + -

Karan

et al.

[11]

? ? + + + + -

Mohebi

et al.

[12]

? ? + + + + ?

Özer et

al. [13]

? ? + + + + -

Cardos

o et al.

[14]

? ? + + + + -

Cochra

ne et al.

[15]

? ? + + + + -

Janisze

wska-

Olszow

ska et

al. [16]

? ? + + + + -

+ = low risk ; ? = unclear risk, - = high risk

8

1. SYSTEMIZATION AND ANALYSIS OF DATA

Collected articles were screened according to PRISMA flowchart (Figure 1). The initial search

identified a total of 193 articles and 18 articles were fully reviewed. According to the title relevance

and exclusion of duplicated articles, 26 potentially relevant articles were identified. Following 8

articles were rejected due to lack of information and not relevant result. Among remaining 18 articles

during eligibility stage, 8 articles were excluded. Finally, ten articles were included, in which have

had evaluated a total of 454 extracted teeth. Exclusion of articles during eligibility stage are as

followed: articles that included in exclusion area such as enamel surface assessed after adhesive

clearance by only qualitative or semi-quantitative method [17-20], tungsten carbide bur is not

included as a comparator [1,3] and study comparing polishing methods under using only one adhesive

removal tool [21,22].

9

Figure 1. PRISMA flowchart

10

Table 3. Characteristics of studies

11

1.1 STUDY CHARACTERISTICS

Total 10 studies finally selected in this systematic review were in vitro studies. Table 4 indicates

regarding quantitative analysis based on an instrumental evaluation of enamel surface

roughness or volumetric enamel loss after adhesive removal and qualitative analysis based on

visual inspection.

It can be seen in table 3 that various tools were used for adhesive removal, among those adhesive

removal methods tungsten carbide burs were described in all studies. So articles included in this

systematic review have tungsten carbide bur as a comparator.

Özer et al. [13] reported that low-speed Sof-Lex disks restored the enamel most successful that

Sof-Lex disks and intact enamel surface have no statistically significant difference at 0.05

significance level. Disks combined with high-speed tungsten carbide bur, fiberglass burs and

fiberglass burs combined with low and high-speed tungsten carbide bur are as followed and

their enamel roughness had not statistically significant difference. The author suggests using

fiberglass burs combined with low and high-speed tungsten carbide burs instead of Sof-lex

disks due to its uncomfortable working area visibility.

Adhesive remnant removed faster with high-speed tungsten carbide bur than the other methods,

but visual inspection and volumetric enamel roughness parameter demonstrated that it is more

destructive to enamel surface compared with other methods combinations. Also, study

concludes that low-speed tungsten carbide bur proved to be unsuitable for adhesive removal.

Therefore, high and low-speed tungsten carbide bur cannot be used alone and polishing must be

followed. Low-speed tungsten carbide bur produced higher surface roughness than with high-

speed tungsten carbide bur and author described that this outcome might be related to the

pressure applied when adhesive removal with low-speed tungsten carbide bur. The author

recommended using Sof-Lex disk and fiberglass burs due to their efficiency even though they

took longer time than high and low-speed tungsten carbide bur [13].

A similar study was done by Cardoso et al. [14], they also concluded Sof-Lex disks produced

the least enamel roughness followed by fiberglass burs and high-speed tungsten carbide burs.

However, the study found that ultrasonic scaler and adhesive removing pliers shown

significantly increased enamel roughness that even ultrasonic scaler cause unacceptable

surfaces with large and deep scratches.

12

In the study of Cochrane et al. [15], low-speed aluminum oxide polishing disc and low-speed

tungsten carbide bur produced significantly less enamel damaging depth than high-speed

tungsten carbide bur that the results are contrasted to Özer et al. [13] due to the operator's

different pressure applying for adhesive removal. In this study, authors stated that this is because

high-speed tungsten carbide bur produce high blade torque with less operator handpiece

pressure and this makes burs are less sensitive to density difference in enamel.

On the contrary, with low-speed tungsten carbide bur removal has low torque with higher

operator handpiece pressure resulting in minimal damage to enamel because of increased

hardness of burs and high modulus of elasticity. The greatest mean depth of damage was

obtained by high-speed bur and ultrasonic scaler and they showed similar enamel lesion depth

[15].

Banerjee et al. [4] in their study concluded that 45S5 bioactive-glass air-abrasion produced less

mechanical damage to enamel surface than low-speed tungsten carbide bur and Alumina air

abrasion caused more enamel loss than the tungsten carbide bur. Taha et al. [10] reinforced this

result which published more recently and reported both glass air-abrasion method(45S5 and

QMAT3) showed less damage than tungsten carbide bur on enamel surface and QMAT3

produced the lowest enamel roughness among them regardless of the adhesive material used.

They described this new experimental fluoride-containing bioactive glass powder (QMAT3)

makes it possible to clean up the residual adhesive selectively without inducing damage on

enamel surface due to the characteristic that it has lower hardness value than enamel surface.

However, glass air-abrasion took about twice longer time than tungsten carbide bur.

In Mohebi et al. [12], in their atomic force microscopy studies, reported that white stone burs

produced a smoother surface than tungsten carbide bur under loupe magnification while

tungsten carbide bur showed the roughest surface but there is no statistically significant

difference. Duration of adhesive removal with white stone bur took more prolonged time(56.6s)

than tungsten carbide bur(34,2s) and tungsten carbide bur under loupe magnification(33.6s).

The mean time difference between the tungsten carbide bur and tungsten carbide bur under

loupe magnification was not statistically significant(P>0.05).

The author mentioned that despite the white stone bur and tungsten carbide bur showed similar

enamel surface roughness after resin removal, the time required for adhesive removal showed

significant differences among the methods mainly due to differences in the cutting efficiency

of the instruments which determined by the speed of rotation, bur type, and a number of blades

13

[12]. Karan et al. [11] obtained a similar conclusion about the relationship between time-

consuming for adhesive removal and characteristic of bur. Result showed statistically

significantly difference between tungsten carbide bur and composite bur, with the tungsten

carbide bur produced higher average maximum roughness depth (P<0.001). But tungsten

carbide bur required shorter time(40s) than composite bur(84.2S) for adhesive removal and the

reason for this is due to cutting efficiency of instruments that carbide burs have an aggressive

cutting with the sharp blades and composite burs have no blade. Composite burs peeled off by

dividing of fibers into fragments during abrasion and a new part of glass fiber was revealed.

The study considered that time-consuming method could not be preferred despite better

efficiency to the clinician so that tungsten carbide bur used first to remove heavy residual

remnant and composite bur can be used for the last removal of the last adhesive layer close to

the enamel.

Ahrari et al. [7] found that cleaning adhesive remnant with low-speed tungsten carbide bur

showed the least surface roughness values and also surface irregularity was not significantly

different between adhesive removal and finishing stage. High-speed tungsten carbide bur showed

a minimal degree of irreversible enamel damage compare to ultrafine diamond bur and Er: YAG

laser which causes a significant and irreversible increase in the enamel surface irregularity while

ultrafine diamond bur showed a much less roughened surface than the Er: YAG laser.

In the study of Sigilião et al. [6] reported that the smooth surface was obtained by 30-blade

tungsten carbide bur in low speed, DU10CA ORTHO polisher, Renew finishing system and

Diagloss polisher. 12-blade tungsten carbide bur in low and high-speed handpieces showed no

significant differences in mean enamel surface roughness before bonding and after debonding.

However, in the evaluation of the average maximum peak to valley height, high speed 12-blade

tungsten carbide bur only shown increased enamel roughness among adhesive removal methods.

Low speed 30-blade tungsten carbide bur and Diagloss polisher required a longer time than other

methods.

Janiszewska-Olszowska et al. [16], in their 3D laser microscope studies, the result of enamel

roughness parameter showed Adhesive Residue Remover as the smoothest and most repeatable

enamel surface(lowest variance) and followed by one step polisher and finisher. Tungsten

carbide bur showed the roughest surfaces and the highest amount of enamel removing.

14

Table 4. Evidence table arranged enamel damage by assessment methods

Authors

and Year

Qualitative

or

Semi quantitative assessment

Quantifiable assessment

(Mean (± SD))

Mean time(±SD) in

seconds for adhesive

resin removal

Banerjee

et al. [4]

2008

Enamel surface under 250xSEM magnification

Group 1(8-bladed tungsten carbide bur at low speed): lined up

with the long axis of the bur. Seen most severely damaged surface

Group 2(Alumina air-abrasion): the rough enamel surface has

sharp peaks that were closely placed

Group 3 (Bioactive glass air-abrasion): the rough enamel surface

had peaks that were placed further apart and were more rounded

than those created by the alumina air-abrasion,resulting in a less

rough appearance

Enamel loss (mm3)

Group 1: 0.285(±0.075)

Group 2: 0.386(±0.254)

Group 3: 0.135(±0.033)

-

Sigilião et

al. [6] 2015

Enamel surface under 500xSEM magnification

Group 1 (12-blade tungsten carbide bur at low speed): scratches

Group 2 (12-blade tungsten carbide bur at high speed): deeper

scratches than group 1

Group 3 (30-blade tungsten carbide bur at low speed): surface

more similar to the original tooth

Group 4 (DU10CA ORTHO polisher) & Group 5 (Renew

Finishing System): loss of perikymata with fine scratches

Group 6 (Diagloss polisher) : well-marked and deep fine

scratches caused by the diamond particles embedded in rubber

Initial and final enamel roughness(µm)

Group 1: 6.03(±3.04) /5.48 (±0.59)

Group 2: 8.16(±2.16) / 8.66(±1.75)

Group 3: 7.90(±2.33) / 5.16(±1.77)

Group 4: 6.25(±2.31) / 5.82(±1.62)

Group 5: 6.04 (±1.50) /4.65(±1.00)

Group 6: 8.07 (±2.47) /5.35(±1.06)

Group 1: 34.0 (±5.73)

Group 2: 23.5 (±5.01)

Group 3: 57.5 (±19.9)

Group 4: 31.8 (±4.56)

Group 5: 31.9 (±5.85)

Group 6: 63.5 (±13.8)

Ahrari et al.

[7] 2013

-

Roughness depth in the adhesive

removal stage and finishing stage (µ)

Low-speed tungsten carbide bur :

2.21(±0.53) / 1.64(±0.72)

High-speed tungsten carbide bur :

3.76(±1.16) / 2.98(±1.23)

Daimond bur: 5.81(±0.72) /

-

15

4.19(±1.10)

Er:YAG laser:10.25(±3.01)

/7.51(±2.15)

Taha et al.

[10] 2018

Enamel surface under 250xSEM magnification

Group 1 (Low speed tungsten carbide bur): roughened and pitted

surface

Group 2 (45S5-air-abrasion): some area has microscopic

roughness

Group 3 (QMAT3-air-abrasion): uniformly smooth surface

Enamel surface roughness(µm)

Bracket bonding using

composite resin (Transbond XTTM) /

Resin modified glass ionomer cement

(Fuji Ortho LCTM)

Group 1: 2.93 (±0.06) / 2.57 (± 0.05)

Group 2: 1.89 (±0.04) / 1.59 (± 0.02)

Group 3: 0.58 (± 0.02) / 0.51 (± 0.04)

Bracket bonding using

composite resin / Resin

modified glass ionomer

cement

Group 1:

23.20(±4.99)/22.90

(±4.41)

Group 2:

40.71(±2.89)/38.42(±4.

29)

Group 3:

42.51(±3.51)/40.32(±3.

36)

Karan et al.

[11] 2010

3D views were obtained by AFM scans

Low speed 8-bladed tungsten carbide bur showed significantly

rougher surfaces than low speed composite bur

Enamel surface roughness(nm)

in prebond and resin removal stage

Low speed tungsten carbide bur :

324.40( ±115.87) /587.37 (±143.46)

Composite bur:

394.38(±149.97)/297.23(±124.72)

Tungsten carbide bur

:40 (min.: 31, max.: 57)

Composite bur: 84.2

(min.:61, max.:122)

Mohebi et

al. [12]

2017

-

Average enamel roughness(nm)

Low speed 12-bladed tungsten carbide

bur ≈ 550.00

White stone≈ 390.00

Low speed 12-bladed tungsten carbide

bur with loupe camera ≈ 420.00

Tungsten carbide bur:

34.2 (±5.12)

White stone bur:

56.5 (±10.66)

Tungsten carbide bur

under loupe

magnification:

33.6 (±7.24)

Özer et al.

[13] 2008

Enamel surface under 750xSEM magnification

Group 1(High speed tungsten carbide bur): scratched surface with

Enamel surface roughness(µm)

Intact enamel :2.04 (±1.16)

Group 1: 6.22(±1.08)

Goup 2: 13.02(±2.96)

16

deep grooves

Group 2(Low speed tungsten carbide bur): the most worst case,

punctured,scratched and scarred surface with protuberances and

grooves

Group 3 (Sof-Lex disks): the most even roughened surface

Group (1+3): smooth, scratched surface

Group (2+3) & group (1+4): scarred surface

Group (2+4) & group 4(Fiberglass bur) : some scarring but

shallow than group 1,(2+3) and (1+4)

Group 1: 8.23 (±2.77)

Goup 2: 7.54 (±3.42)

Group 3: 2.42 (±1.89)

Group 1+3: 4.56 (±2.13)

Group 2+3: 6.93 (±3.76)

Group 4: 4.67 (±1.17)

Group 1+4: 5.54 (±2.41)

Group 2+4: 5.34 (±3.72)

Group 3: 24.63(±6.22)

Group 1+3: 25.76

(±4.03)

Group 2+3:

30.82(±5.68)

Group 4: 23.62(±4.24)

Group 1+4: 26.19

(±3.78)

Group 2+4: 31.64

(±4.57)

Cardoso et

al. [14]

2014

Mean ESI (kruskal-wallis analysis) in adhesive removal stage and

polishing stage

Group 1(High speed tungsten carbide bur):

2.3 / 2.5

Group 2(Sof-Lex discs): 1.5 / 1.3

Group 3(Adhesive removing plier): 1.6 / 1.3

Group 4(Ultrasonic scaler):3.2 / 2.8

Group 5(Fiberglass burs): 1.6 / 1

Enamel surface roughness in the

adhesive removal stage and polishing

stage (µm)

Group 1: 0.8291 (±0.2983) /

1.0151 (±0.3226)

Group 2: 0.4701 (±0.0674) /

0.4401(±0.1977)

Group 3: 1.7401 (±0.0339) /

2.0909 (±0.7268)

Group 4: 2.2601 (±0.5544) /

1.9793 (±0.5369)

Group 5: 0.7456 (±0.2319)/

0.7362 (±0.1647)

-

Cochrane

et al. [15]

2012

Enamel surface under 3000xSEM magnification

Group 1(Low speed 16-fluted tungsten carbide bur with water

coolant) & Group 2(High speed 12-fluted tungsten carbide bur

with water coolant): Well demarcated horizontal scratches

(scratches were more well defined in group 1)

Group 3(Low speed aluminum oxide polishing disc without

coolant): smooth surface with few minor scratches

Group 4(ultrasonic scaler with coolant) : highly irregular

Enamel damage depth (µm)

Group 1: 7 (±2)

Group 2: 18 (±7)

Group 3: 16 (±6)

Group 4: 4 (±1)

Group 1: 23 (±2)

Group 2: 16 (±2)

Group 3: 102(±22)

Group 4: 16 (±1)

17

SD= standard deviation ; ESI= enamel surface index; SEM = scanning electron microscopy; AFM = atomic force microscopy

*Indices aiding visual enamel evaluation [14]: Enamel surface index(ESI) by Zachrisson and Arthun’s criteria; 0 – perfect surface with no scratches and

distinct intact perikymata, 1 – satisfactory surface with fine scratches and some perikymata, 2 – acceptable surface with several marked and some deeper

scratches, no perikymata, 3 – imperfect surface with several distinct deep and coarse scratches, no perikymata

damaged surface

Janiszewsk

a-

Olszowska

et al. [16]

2016

-

Height of enamel surface roughness

(µm)

Intact enamel: 1,8902 (± 0.3575)

Tungsten carbide bur: 1,0911 (±

0,3257)

Shofu One Gloss: 0,8601 (± 0,3397)

Adhesive residue remover: 0.7521 (±

0,1744)

-

18

DISCUSSION

Our focused question was what kind of method is the most efficient for adhesive removal on

enamel surface which causes the least damage to enamel. According to total 10 articles with

454 extracted teeth which were experimented with various interventions, each study showed

consistent result based on quantitative analysis. Tungsten carbide burs were compared with

other methods in all articles and each study concluded that tungsten carbide showed less time

consuming on adhesive removal especially at high-speed handpiece but more destructive than

other methods such as a Sof-Lex disk, composite bur, fiberglass bur, glass air-abrasion, adhesive

residue remover and one step polisher and finisher. From the angle of efficiency, time

requirement or cost, it is recommended to use those methods in combination. For example, high

or low-speed tungsten carbide bur can be used first for the visible adhesive removal on enamel

surface and then other methods mentioned above can be used as followed for removing last

adhesive layer intimate to enamel. Diamond bur, ultrasonic scaler, adhesive removing pliers

and laser cause significant irreversible enamel damage so that should not be used.

The studies in the present systematic review showed heterogeneity because of the high diversity

of enamel surface assessment instruments. All ten studies presented results of enamel surface

irregularity or enamel surface loss in different amounts (volume or surface depth) assessed with

various quantitative instrumental methods. Among ten articles, four had only average

roughness which indicates the arithmetic mean of all absolute distances of the surface

roughness from the center line within the measuring length. Some studies assert that this

parameter has limitation for surface profile registration. According to Sagiliao et al. [6], many

studies use the average roughness value as the only indicator of surface smoothness. However,

this universally accepted parameter has limitations when used alone because it can not discover

the profile of irregularities and distinguish between scarred surface’s peaks from valleys. In

case of average maximum roughness height, it enabled us to recognize vertical profile.

Similarly, according to Mohebi et al. [12], to find the precise profile, to have a better view of

surface irregularity, we should use not only average roughness value but also root mean square

roughness and average maximum peak to valley height parameters. Different methodology

results in this difference in this systematic review and this could have been avoided if more

standardized methodological approaches had been adopted by the original studies.

Seven articles included in this systematic review showed also qualitative analysis add on to

quantitative analysis, 6 with scanning electron microscopy and 1 with atomic forces microscopy

scans, which indicate visual information of enamel surface by scanning a focused electron beam

19

over a surface to create an image. Few articles which were using scanning electron microscopy

alone on evaluating enamel surface were excluded from this review during assessing eligibility

stage in PRSMA flowchart [8]. It is because many studies reporting that qualitative analysis

which has only subjective information can be used only as a supportive tool for quantitative

evaluation methods.

Not consensus about the efficiency of polishing after adhesive removal but Janiszewska-

Olszowska et al. [16] asserts that enamel roughness caused by adhesive removing tools cannot

be smoothened by polishing. Similarly, Ahari et al. [7] stated that final polishing could not

restore enamel roughness to its original roughness values before treatment. And Cardoso et al.

[14] also reported pumice paste polishing was optional because according to quantitative results,

by comparing mean enamel roughness before and after polishing, polishing does not affect

significantly on mean enamel roughness and it could not restore enamel to initial state.

Therefore, it should be cautiously focused to choose the adhesive removal method to minimize

enamel damage.

The study of Cochrane et al. [15] assessed and compared effect of adhesive removal

methods all on sound, remineralized and demineralized enamel surface. Discs showed

least destructive on both demineralized and remineralized enamel. Low-speed tungsten

carbide bur and ultrasonic scaler should not be used on both of them. Remineralization

of enamel leads to a reduction in depth and area of lesion whether which adhesive

removal method is used. This result provides evidence to support remineralization of

white spot lesions before adhesive removal to prevent iatrogenic damage.

Only in vitro studies on extracted human teeth were included in this review. However, the

experimental conditions such as good illumination, moisture control, and an optimal viewing

angle may differ from an in vivo condition thus highlighting the necessity for future clinical

trials intraorally when estimating the intervention effect.

20

CONCLUSIONS

Obviously removing adhesive remnant increased surface roughness and could not be restored in its

original enamel condition. The result shown in total 10 articles, tungsten carbide bur required less

time consuming for adhesive removal than other methods but showed rougher enamel surface than

Sof-Lex disk, fiberglass bur, composite bur, glass air-abrasion, residual adhesive remover and one

step polisher and finisher. However, in aspects of efficiency, time requirement or cost, it is

recommended to use those methods in combination. Diamond bur, laser, adhesive removing plier and

ultrasonic scaler can cause irreversible iatrogenic damage to enamel so that should not be used for

adhesive removal. The results can be different according to different enamel surface assessment

methods and clinical conditions so further researches should be performed in order to discover

adhesive removal method for perfect adhesive clean up and combination among them which can

minimize enamel loss and preserve the original tooth state as much as possible.

21

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