02

Proceeding The

International

LDRG-KKU Symposium 2013

An in-vitro study on the physical and histological effects of welding technique with 808nm diode laser Pensiri Saenthaveesuk*, Nawarat Sanjandee**, Teerapat Treeratsakulchai**, Peerapat Nora teethan**, and Sajee Sattayut***

Abstract Objective: This study aimed to explore immediate physical and histological characters of the tissue blocks irradiated with 808 nm diode laser at the doses used in practice for promoting oral soft tissue healing. Materials and Methods: The in vitro experiment was composed of 2 parts asfollows: - 1). surface temperature measurement and 2). immediate gross and histological exploration. The experiment was conducted in tissue blocks from ventral sites of the fresh pig tongues. All samples were randomly allocated into 4 groups; 10 samples in each group, according to the diode laser irradiation in continuous mode for 1 second by varying the powers at 1 watt, 1.5 watt, 2 watt and 0 watt as the control. The gross appearance was immediately inspected before the specimen was fixed and stained with Masson's Trichrome. The histological effect was observed under light microscope. The descriptive statistic was use to explain the results. Result: In the 1 watt group, there were 7 specimens observed change in color and showing ablation while 3 specimens showed histologically coagulative and vaporized areas. All of the samples in the 1.5 watt and 2 watt groups showed physical changes from yellowish color to ablation. The histological vaporization was found in 4 specimens and 7 specimens in the 1.5 watt and 2 watt groups, respectively. From Fisher's exact test, there was statistically significant difference in the numbers of samples with physical and histological alterations among the groups at p value -0.0001 and 0.003, respectively. Post-hoc comparison using Bonforroni correction at P value 0.5 showed that all of experimental groups had the larger numbers of samples with observed gross- alteration than the control. For the histological alteration, there was only the 2 watt group showed the larger numbers of histological changes than the control. Conclusion: The 808 nm diode laser at 2 watt irradiating for 1 second provided the significant numbers of physical and histological observations than the control while the 1 watt and the 1.5 watt showed only significance in physical alteration.

There was a previous study mentioning the

Introduction

use of 830 nm diode laser called "Laser tissue welding

Currently, treating erosive type Lichen planus

technique"2.

with topical steroid treatment has limited because some patients cannot tolerate it's side effect or response to such a treatment'.

* Lecturer in Oral Surgrev Department and affiliate researcher, Lasers in Dentistry Research Group, Khon Kaen University, Thailand "* Dental Student, Faculty of Dentistry, Khon Kaen University and affiliate researcher, Lasers in Dentistry Research Group, Khon Kaen University, Thailand **" Associate Professor in Oral and Maxillofacial Surgery and Lasers in Dentistry Research Group, Khon Kaen University, Thailand

36

Proceeding The

International

LDRG-KKU Symposium 2013

This showedthe changes of collagen fiber in

temperature changes from the room temperature by the group

vascular of which stimulated healing after irradiated by

were shown in table 1. The average surface temperature

diode laser. Gulsoy et a13 compared the wounded closure

of the 1 Watt group was 23.73°C while the 1.5 Watt and

between using 980 nm diode laser and silk suturing in

2 watt groups had surface temperatures of 24.76°C and

mice's skin incision. From histological exploration, it was

23.48°C respectively. This experiment was undertaken

found that using of laser seemed topromote healing and

at 27°C of air room temperature (Table 1).

wound closure together with reducing scars and inflam-

the laser doses used in this experiment did not seem to

mation.

increase surface temperature of the tissue blocks.

Therefore,

There was a case report by Sattayut4 found the

In part 2, immediate gross and histological changes were

benefits of 830 nm diode laser at1 to 2 watts on treating

described by the groups based on laser power setting.

refractory and non-responsive erosive type lichen planus

All of 40 specimenscategorized by the groups were de-

to topical steroid. However, there has been no study in

scribed in Table

any histological characteristic of this technique. It is worth

• The control; 0 Watt group

exploring histologically in order to explain the clinical

O 10 specimens had no gross and histological

efficacy of this laser tissue welding technique.

changes detected • The 1 Watt group O 10 specimens were described as follows:-

Objective

Gross sample observation

This study aimed to explore immediate physical and histological characters of the tissue blocks irradiated

3 specimens; undetectable change

with 808 nm diode laser at 1 watt, 1.5 watt and 2 watt.

2 specimens; brownish macule 2 specimens; yellowish macule (fig.3) 2 specimens; whitish macule

Materials and Methods

1 specimen; clear macule

The in vitro experiment was composed of into

Histological change

2 parts as follows:- 1). surface temperature measurement

7 specimens; no change could detect under

and 2). immediate histological exploration.

the light microscope (fig.4)

In part 1, the surface temperatures of 808 nm diode

3 specimens; Found vapourization and

laser irradiation at 1 watt, 1.5 watt and 2 watt were repeatedly measured for 10 times of each setting (fig.1). Part 2, the

coagulation zones as detailed in table 3.

immediate histological exploration was undertaken in

• The 1.5 Watt group

40 tissue blocks from the ventral sides of the fresh pig

O 10 specimens were described as follows:-

tongues. The samples were randomly- equally allocated

Gross sample observation:

into 4 groups, namely, 1 watt, 1.5 watt, 2 watt and 0 watt

2 specimens; brownish pit.

(the control). The irradiation time was 1 second for each sam-

1 specimen; yellowish pit.

ple (fig.2). Then all samples were fixed with 10% formalin

3 specimens; yellowish macule. (fig.5)

and stained with Masson's trichrome. The vapourized depth,

2 specimens; white macule.

vertically affected depth and horizontally affected width

2 specimen; clear macule. Histological change

were observed and measured under light microscope (10x10

7 specimens; no change could detect under

magnification) using calibrated soft ware programme

the light microscope. (fig.6)

(for Nikon ECLIPSE 801, D5-Fi-L2 camera control unit).

3 specimens;found vaporization and

The descriptive statistic was use to explain the results.

coagulation zones as detailed in table 3 • The 2 watt group

Results

O 10 specimens were described as follows:-

Part 1, the means and standard deviations

Gross sample observation:

of surface temperature measurement and difference of

37

Proceeding The

International

LDRG-KKU Symposium 2013

3 specimens: dark brown pit (fig.7)

alteration, there was only the 2 watt group showed the

1 specimen: yellowish pit

larger numbers of this than the control (Table 4). From

1 specimen: light yellow pit

the analysis of crosstab on the relationship between gross

1 specimen: whitish pit

and histological alteration were shown in table 5

1 specimen: yellowish macule 2 specimens; whitish macule

Discussion

1 specimen; clearmacule

In our experiment, it some samples showed the changes and not changes in observing gross specimens

Histological change

immediately after irradiated of laser without histological

3 specimens; no change could detect under

changes. This event able to explain by bio-modulation

the light microscope.

mechanism of low intensity laser, it isn't alteration from

7 specimens; found vapourization and

the ablation mechanism4.

coagulation zones (fig.8) as detailed in table 3

Moreover, we didn't find that the temperature was raised up to 60°C. This might be the new discovery

From Fisher's exact test, there was statistically

which is different from the hypothesis saying that the

significant difference in the numbers of samples with physical

temperature must be reached to 60°C to find the altera-

and histological alterations among the groups at p value =

tion of soft tissues' 6. Therefore, the further study should

0.0001 and 0.003, respectively. Post-hoc comparison using

be a comparison of the gross and histological alteration

Bonforroni correction at P value 0.5 showed that all of

between this setting and the setting of which increasing

experimental groups had the larger numbers of samples with

the surface temperature to 60°C.

observed gross- alteration than the control. For the histological Table 1 Means surface temperature and their differences by the groups. Average

SD of Average

Difference (before and after

SD of the difference

(Celsius degree)

(Celsius degree)

laser irradiation)

(delta-T)

1.5 watt

23.73 24.76

0.60 0.48

1.75 1.75

0.50 0.45

2 watt

23.48

1.14

1.42

0.70

Group 1 watt

Table 2 Immediate physical alteration by the groups. Histo

Gross

Group Unseen

Change

No change

Change

Gr. Control

10

0

10

0

Gr. 1

3

7

7

3

Gr. 2

0

10

6

4

Gr. 3

0

10

3

7

Table 3 Immediate histological exploration measurement by the groups. Depth of vertically Depth of vapourisation Group Median

Percentile 75th 25th 52.38 271.75 163.98 94.14

1 watt 1.5 watt 2 watt

269.57 123.73 175.04

132.11

Control

0

0

211.80 0

Width of horizontally

affected area Percentile Median 25th

186.53 157.94

138.07 126.04

225.13 0

156.39

38

0

affected area Percentile Median

75th

214.50 173.16 293.00 0

25th

75th

360.70

402.31 398.51

581.80

305.15 428.86

0

0

0

389.86 351.48

647.48

I'roceeding The 3'4 International LDRG-KKU Symposium 2013

Table 4 Statistic analysis. Gross

P-value

Gr. 1- Gr. 2

0.048

Gr. 1- Gr. 3

0.009

Gr. 1- Gr. 3

0.07

Gr. 1- Gr. control

0.003

Gr. 1- Gr. control

0.211

Gr. 2- Gr. 3

0.37

Gr. 2- Gr. 3

0.37

Gr. 2- Gr. control

0.000

Gr. 2- Gr. control

0.087

Gr. 3- Gr. control

0.000

Gr. 3- Gr. control

0.003

Histo Gr. 1- Gr. 2

P-value 0.628

Fisher's Exact test: p-value < 0.005

Table 5 crosstab analysis. Unseen

Macule

Pit

13

13

-

Found coagulation

1

1

Found coagulation and vaporization

4

8

Undetected

Figure 1 Measuring surface tissue temperature

Figure 2 Immediate gross exploration.

Figure 3 A yellowish papule on the surface of the sample at the irradiated site

39

Proceeding The 3' International LDRG-KKU Symposium 2013

Figure 5 A yellowish macule on the surface of the sample at the

Figure 4 No histological change can be detected.

irradiated site

Figure 7 A dark brown pit on the surface of the sample at the

Figure 6 No histological change can be detected.

irradiated site

Figure 8 Histological changes and their measurements

40

Proceeding The

e international

LDRG-KKU Symposium 2013

2.

Conclusion

Tang J, O'Callaghan D, Rouy S, Godlewski G. Quantitative

After studies histological of sample specimen after

Changes in Collagen Levels Following 830-nm Diode

irradiated with 808 nm diode laser that different energy

Laser Welding. diode laser; laser welding; collagen

level, most of specimens irradiated with 1 watt and 1.5

quantitative change. 1998; 22:207-211. 3.

watt laserwere able to notice changes in physical with-

Gulsoy 0. Closure of skin incisions by 980- nm diode laser welding. Lasers Med Sci. 2006; 21:5-10.

out histological alteration. These were found yellowish 4.

macule in gross specimens.The majority of specimensir-

Sattayut S. Novel technique for using the diode laser to

radiated with 2 watt laser have significant changes in

treat refractory erosive oral lichen planus. [web site on

both histological and physical. It was found physical

the Internet] 2011 3 aug [cited 2011 1 oct]; Available

change to brownish pit and vapourizationand coagulation

from: http://www.oemus.com/archiv/pub/sim/le/2011/

in histological finding.

le0311/1e0311_18_20_sattayut.pdf 5.

The 808 nm diode laser at 2 watt irradiating for

Pik gfritpni. viant-mlikwinimioviummu. Khon Kaen Dental Journal. 2003; 6(2):89-95.

1 second provided the significant numbers of physical 6.

and histological observations than the control while the

ColuzziDJ. An overview of laser wavelengths used in dentistry. Dent Clin North Am. 2000; 44(4)753-65.

1 watt and the 1.5 watt showed only significance in physical alteration.

Correspondence and Reprint Request to:

Reference

Dr. Pensiri Saenthaveesuk

1. Thongprasom, K, Leugvisut P, Wongwatanakij A,

Department of Oral and Maxillofacial Surgery, Khon Kaen University, Thailand, 40002

Boonjatturus C. Clinical evaluation in treatment of oral lichen planus fluocinolone acetonide:A 2-year followup. J Oral Pathol Med. 2002; 32(6):315-22.

41

Proceeding The 3' International LDRG-KKIJ Symposium 2013

Academic Comments on Extended Abstract: The effect of welding using diode laser on oral tissue

Prof Loh Hong sai, Singapore 1.

Title

It should be more descriptive for "welding" can be associated with blood vessels, nerves, connective tissues etc. Wavelength should be mentioned to interest specific readers. Maybe retitled as: An in-vitro study on the welding effects on tongue collagen tissues with 808nm diode laser 2. Objective The reason(s) for doing this research should be encompassed in the introductory remarks. And mention what is currently available/accepted in the scientific literature, and how this research can further enhance/clarify the subject matter. If it is specific related to Lichen Planus, then, is it the "healing" or "pain-control" aspects that you wish to study? 3. Materials and Method a.

Control at 0 watt is of no value and a given. Perhaps, it would be better to make the control as

that energy mentioned in a similar study, as you wish to verify if other energy levels or parameters could yield better outcomes^ b.

Are there real "critical" outcomes with close energy levels like 0.5W in the groups? Why not expand

to other levels mentioned in other studies too. 4. Results There is no clear description of "welding" of tissues eg what are the histological features seen. Also, need to explain why there were different effects on samples in the same group. Was it due to the focus and direction of the laser beam, or the varying tissue characteristics. 5. References No 6 and 7 are repetitive to the same author. Can there be more updated references in general and including in the area of current laser management of lichen planus.

Extended Abstract: The effect of welding using diode laser on oral tissue

Assoc.prof.Aroon Theerakapong, Thailand

Academic Comment: The study of using 808 nm diode laser for the purpose of tissue welding in fresh pig tongue. The results showed no temperature raised up to 605C in each tissue sample. Basically, laser tissue welding is a time temperature dependent procedure. The extend of tissue reaction to the laser should be explored when increasing the power and time setting for the proper clinical used in the future.

42