Comparison of Shade Selection by Smartphone Camera and DSLR Camera using Vita 3D Master Shade Guide: An Invitro Study

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COMPARISON OF SHADE SELECTION BY

SMARTPHONE CAMERA AND DSLR CAMERA USING

VITA 3D MASTER SHADE GUIDE- AN INVITRO STUDY

A Dissertation submitted

in partial fulfil lment of the requirements

for the degree of

MASTER OF DENTAL SURGERY

BRANCH –I

PROSTHODONTICS

THE TAMILNADU DR.M.G.R. MEDICAL UNIVERSITY

CHENNAI- 600032

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ADHIPARASAKTHI DENTAL COLLEGE & HOSPITAL

MELMARUVATHUR- 603319

DEPARTMENT OF PROSTHODONTICS

CERTIFICATE

This is to certi f y t hat Dr. VI DHU ANTONY, P ost Graduat e student (2016 -2019) from the Depart ment of Prost hodont ics,

Adhi paras akt hi Dent al C oll ege and Hospi tal, M elm aruvathur – 603319,

has done this dissertation titled “COMPARISON OF SHADE SELECTION BY SMARTPHONE CAMERA AND DSLR CAMERA USING VITA 3D MASTER SHADE GUIDE- AN INVITRO STUDY” under our direct guidance and s upervision i n part ial fulfi l lment of the regul ations l aid

down b y t he Tamil nadu Dr. M.G.R M edi cal Uni versit y, Chennai –

600032 for M DS., (Branch - I) Departm ent of Prosthodont i cs Degree

Examination.

Guide Head of the Departm ent

Dr. K. PRABH U, MDS Dr.N.VE NKATES AN, MDS

Reader Professor and Head

Departm ent of P rost hodonti cs

Principal

Dr. S. THILL AINAYAGAM., MDS Professor and Head,

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ACKNOWLEDGEMENT

I t hank AL MI GHT Y GO D for all his bles sings and for being with me throughout and leadi ng me t o prepare and com plet e this

diss ert ati on. I thank our Correspondent Dr. T. Ramesh, MD. for his vital encouragement and support.

I am t hankful to Dr. Thill ainayagam MD S ., our bel oved princi pal , Adhiparas akt hi Dent al Coll ege and Hos pital, M elm aruvathur

for providing m e wi th the opport unit y t o utiliz e t he faciliti es of the

coll ege.

I avail t his opport unit y to expres s m y gr atitude an d reverence to

m y beloved t eacher Dr. N. VE NKATE SAN. MDS. , P rofessor and Head, Depart ment of Pros thodont ics , Adhiparas akthi Dent al College

and Hospit al , M elm aruvathur. Hi s pursuit for perfecti on and immens e

support were a source of const ant ins piration to m e and without whi ch

such an endeavour would never had m at erializ ed.

I am extrem el y t hankful to m y gui de Dr.K. PRABHU, MDS . Words cannot expres s m y grat itude for hi s confi dence i n m y abili t y to

perform thi s st ud y.

It is m y dut y t o express m y t hanks to m y teacher

Dr. A.S. RAMESH , MDS for his favour rendered for m y st ud y.

I am t hankful and express m y gratitude to m y t eachers

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suggesti ons and encouragem ent throughout t he compl eti on of m y M ain

diss ert ati on.

I al so wish to t hank m y seniors, and m y post graduat e coll eagues

Dr.GANAGAMANI , Dr.NIT HYAPRIYA and I warm l y acknowledge

m y juniors Dr.JEEVITHA, Dr.KABIL AN, Dr.MITH RA, Dr. PRAVI N, Dr. PAZHANI and Dr. MUTHU ANNAMAL AI for thei r

hel p and support.

I thank Mr. Maveeran, B.com.,MLIS ., Li brari an and t he librar y staff Mr.K.S elva Ku mar,B.A., Adhi paras akthi Dent al C ollege and Hospital, M elm aruvathur, for favours rendered.

I owe m y grat itude to m y Parents Mr.A.D.ANTONY, and Mrs.S UKRUTH A ANTONY, who stood beside me duri ng m y hard time and s acrifi ced s o much to m ake me what I am t oda y.

I thank m y lovi ng husband Mr. ARUN LEO, who has been a constant source of s upport and encouragem ent duri ng the challenges of

graduat e l ife.

I would als o like t o offer m y heart fel t thanks to m y brother

Mr.VIVI AN ANTO NY, si ster in law Mrs.PONNY LEE, In Laws Mr. UVARAJ and Mrs.(Dr.) THRES I KA UVARAJ for their const ant

encouragem ent throughout m y career.

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DECL ARATIO N

TIT LE OF THE DIS SERTATION

COMPARISON OF SHADE SELECTION

BY SMARTPHONE CAMERA AND DSLR

CAMERA USING VITA 3D MASTER

SHADE GUIDE- AN INVITRO STUDY

P LACE OF THE S TUDY

Adhi paras akt hi Dent al Coll ege and Hospital,

Melm aruvathur -603319.

DUR AT ION OF THE COURSE 3 Years

NAME OF THE GUIDE Dr. K.PRABHU M DS.,

NAM E OF HOD Dr.N.VENKATESAN, M DS.,

I hereb y decl are that no part of t he dis sert ation will be utilized

for gaining fi nancial assi stance or an y prom otion without obt aining

prior permis sion of the P rinci pal , Adhi paras akthi D ent al col lege and

Hospital, Mel maruvathur -603319. In addition, I decl are t hat no part

of this work will be publi shed either i n print or in el ect ronic m edia

without m y gui de’s knowl edge who have been acti vel y involved i n

diss ert ati on. The aut hor has the ri ght to res erve for publ ish work s olel y

with the permiss ion of t he principal , Adhiparas akthi Dent al college and

Hospital, M elm aruvathur -603319.

Guid e Head of Departmen t

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ABSTRACT

BACKGRO UND

The succes s of anterior re storation prim aril y depends on proper shade

sel ection when compared to the nat ural dentiti on. P recis e shade

det ermination is dependent on cli nical skill, shade gui de s ystem and

li ghting condit ions . With technologi cal i mprovement in com muni cat ion

net works , int ernet and el ectroni c gadgets among the cont emporar y

soci et y, a subsequent trans lati on has been developed in the fi el d of

dentist r y too. Since a decade DS LR cam eras have been used in

dentist r y and has proven to be at par with various other ins trum ent al

methods for shade selection. However t here have been rapid increas e of

smartphone cam eras for s hade mat chi ng and eas e of com muni cat ion

with the dent al laborator y. Li ttl e is known about the quali t y of the

image t aken using s martphone camera.

AI M

The purpos e of the stud y is to compare the L, a and b values of DS LR

Cam era and sm artphone camera wit h that of the vit a 3D M as ter s hade

guide and also t o eval uat e the effectivenes s of smartphone camera to

that of the DS LR C amera.

METHO D

A comm ercial shade g ui de (3D m ast er vi ta shade guide, germ an y) was

empl o yed in this stud y. The images of t he indivi dual s hade tabs were

captured using S ams ung S 9 pl us smart phone cam era and DS LR canon

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A total of 104 image was taken i.e, 2 photos for each of the 26 shade

tabs were taken bot h in smartphone camera and DS LR camera. Best

Im age was s el ected depending on the cl arit y and s harpness. Thes e

images were taken on a bri ght da yli ght (t emperat ure 4000 -5000k).

There was a fixed dist ance of 17cm between t he shade t a b and the

camera and the s hade t ab was pl aced in front of a gre y card.

The L,a,b val ues of the raw images of s martphone were obt ained using

col or l ab and that of DS LR cam era was obtai ned usi ng adobe

photoshop. The delt a E Values of sm artphone and DS LR in compari son

with t hat of the m anufacturers shade t ab val ues were not ed us ing col or

lab C IE2000 software.

RESULTS

Wilcoxon si gned rank test is perform ed between DS LR and S martphone

photographs and a st atisti cal l y si gnificant difference are fo und between

the am ount of devi at ion of L,a and b val ues in DS LR and S martphone photographs.

CONCLUS ION

Within t he limit ati on of t his stud y 73% accurac y i s obt ained for DS LR

shade t abs whereas onl y 50% accurac y is obtai ned for sm art phones

images .

KE YWO RDS

Shade s el ection, DS LR Cam era, sm artphone cam era, vit a 3D M ast er

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LIST OF CHARTS

S.NO CHART PAGE. NO

1 Mean ranks of SP˄E - DSLR˄E 37

2 Mean of SP˄E and DSLR˄E 38

3 The change percentage of DS LR and Smartphone

photographs for vari ables L, a and b from the

manufacturing values

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LIST OF TABLES

S.NO TABLE PAGE -NO

1.

L, a, b and delt a E Values of DS LR and

smartphone i mages

30-31

2. Descript ive st ati sti cs of DS LR camera 32

3. Descript ive st ati sti cs of sm artphone cam era 32

4.

The change percent age of DS LR and Sm art phone

photographs for variabl es L, a and b from the

manufacturing values .

33-34

5.

Mean and st anda rd deviation for DS LR and

smartphone cam era

35

6.

Mean ranks of Smartphone delt a E and DS LR

delt a E

35

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LIST O F FIGURES

S.NO FI GURE DESCRI PTION PAGE -NO

1 Color Lab space 02

2 Arm am ent arium 22

3

Set up of DS LR C am era whi le capt uring t he image

of shade t ab .

24

4

Set up of sm art phone cam era whil e capt uring t he

image of shade tab

25

5 L a b value for DS LR image in Adobe Photoshop 28

6 Smartphone im age pl aced in Color Lab 29

7

L a b values of sm art phone image obt ained using

col or Lab

[image:11.595.80.521.127.483.2]

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LIST O F ABB REVI ATIO NS

SP SMARTP HONE

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Introduction

Page 1

Accurat e Shade m at chi ng is a chal lenging aspect of aestheti c

dentist r y. The color of an obj ect i s a charact eri sti c gi ven b y the li ght

that com es from t he obj ect t o the hum an e ye and is dependent on the

li ght wavel engt h and the subj ective experi ence – visual perception of

col ors is a ph ys iol ogical phenom enon bas ed on the vi sual s ys t em.

Traditi onall y, s hade mat chi ng of teeth in denti str y is done b y

visuall y com paring t he color of toot h/t eeth with st andard shade guide

tabs , the operator choosing that whi ch he/she deems t o be t he best or

clos es t match.1 Thes e shade guides offer relat ivel y qui ck and cost -effective m ethods of shade m at ching, offset b y t he major problem s of

the subjecti ve variabilit y of shade matching, the pol ychromat ic nature

of teet h, and the limitati ons of dent al shade guides that incom plet el y

repres ent the colour range of natural t eeth.2 Since color perception vari es not onl y am ong individuals but for the sam e indivi dual over

time, s everal m ethods were recentl y used to ass ess tooth color wh ich

incl udes spectrophotomet er, colorim et er, spectroradiom et er, image

anal ys is t echniques etc.

There are different color s yst em s available like gre ys cal e, R GB,

CMYK, l ab et c. The ol dest color s ystem whi ch was created b y Al bert

H.Muns ell i n 1905 at tribu ted Hue, value or li ghtnes s and chroma.

C IE LAB is a col or space specified b y the Int ernat i onal

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Introduction

Page 2

hum an e ye and was creat ed to serve as a devi ce -i ndependent model to be us ed as a referenc e. The three coordinat es of C IE LAB repres ents the li ghtnes s of the col or(L= 0 yi el ds bl ack and L =100 indi cat es di ffus e whit e), it s position between red and green (“a ” negative val ue indi cat es green and positi ve value indi cat es red) and its positi on bet ween yell ow and blue (“b*” negative value indicate blue and positive value indicate yell ow) The m easure of change i n visual percepti on of t wo given

col ours is denot ed b y ΔE - (Delt a E, dE). It is a m etric for

understandi ng how t he hum an e ye percei ves colour di fference

.

Clark in 1931 introduced a custom shade guide whi ch was based

on vis ual as sessm ent of human teet h, and was recorded i n Muns ell ’s

s yst em of Hue, val ue and chrom a. Since t he avai lable shade guides had

few deficiencies, Sproull in early 70’s suggested that an ideal shade

[image:14.595.133.449.335.617.2]

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Introduction

Page 3

preferabl y bas ed on Muns ell color s yst em. As p er Mill er , the thi cknes s

of shade gui de should not be more than the average porcel ain veneer

and the m at eri al should als o be sam e as that of the restoration. The

limitat ions of shade guides are factors that compromis e shade -matching

procedures i n dent istr y and cont ribut e t o the diss ati sfaction of

clini ci ans, t echni ci ans and pati ents.3 To overcom e t hese deficienci es new generation shade guides were developed li ke Vita 3D master shade

guide whi ch features a s ys t em ati c di stri bution of shade t abs withi n the

col or space and Shofu offered the nat ural color concept .

The us age of di git al cameras have been widel y adopt ed in recent

years in t he fi el d of dentist r y. During communi cation wit h t echnici ans,

dentists can pres ent not onl y the dental morphol ogy and colors, but

also the surface t exture, color di stri buti on and other inform at ion under

the i ntra -oral condit ions. Intra -oral images wit h the reference shade

tabs correctl y positi oned next t o the teeth are also us eful in shade

mat ching. S hade m atchi ng using the di gi tal i mages can mi nimise the

gap of col or communication bet ween dent ists and t echni ci ans .

In thi s modern era of technol ogy Sm art phones cam eras are

repl aci ng DS LR camera and have becom e prevalent devi ces.

Im proving hardware and faster wirel es s standards have bol stered the growth of the sm art phone industr y. With ever y new l aunch of smartphones the camera specifi cations have al so im proved to a l ev el

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Introduction

Page 4

healthcare professi onals have increased. Reason behind the increased

use of smart phones include bett er port abil it y, l ess bul k y, les s

noti ceable and m ore conveni ent , thei r self -contai ned CP U computi ng

capabilit y, enri ched fu nctional iti es, various software applications,

wirel ess connectivit y, and hi gh -res oluti on photographic t echnology.

Dedicat ed photographs captured b y sm artphones ma y be us ed as color

references in dental shade m at ching. Because col or com m uni cati on

requi res phot ographs wit h reference s hade tabs, sm artphones can

increase the eas e of wi reless com muni cation bet ween dentis ts and the

laborator y techni ci ans who fabricat e dent al prosthes es.

The aim of the st udy i s to compare t he L,a,b values of im age

taken i n sm art phone and DS LR cam era with t hat of the vit a 3D s hade

tabs and creat e a standard for sm artphone phot ograph y for shade

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Aim and Objectives

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The purpos e of the st ud y i s t o

a) Compare t he L,a and b values of DS LR Cam era with that of the

Vit a 3D M ast er s hade guide.

b) Compare the L,a and b val ues of sm art phone cam era with that of

the vit a 3D Master s hade gui de.

c) Ass ess the effectiveness of sm artphone cam era in s hade

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General Review

Page 6

Shade m at ching of natural teet h wit h arti ficial restoration is one

of the most chall enging as pect of prost hetic denti str y. Color of natural

teeth will var y in color and shape. These variat ions of t ooth shows

different background and personal it y of the pati ent. Whether we ar e

restoring one tooth or m an y, the abi lit y to ass es s and properl y

comm uni cate inform ation to our laborator y can be great l y im proved b y

learning the l anguage of color and li ght charact eristi cs .4

In vi sual color m at chi ng Tooth s hade g uides offer a seri es of

standards si mul ating the natural t eeth, and the dentist mus t deci de

whi ch st andard offers the m ost accept abl e col or m atch with t he toot h or

teeth i n question and if such a mat ch will pleas e t he pati ent .5

Kuehni clai m that i n norm a l color percepti on 2 mil lion col ors

can be distinguis hed when seen on a gre y background 6 and, using logi cal reas oni ng and experim ents, he has demonst rated that a realisti c

val ue for the number of stim uli that can tri gger color percepti ons is

around 40 mil lion 7. The receptors locat ed in the cent ral area of the ret ina, cone cells, are respons ibl e for da yt ime vi ewing and for the

identificati on and differenti ation of col ors 8. Col or perception is a chain process t hat involves the cone cell s that are di vided i nto 3 t ypes

of cel ls that react to three different wavel engt hs corres pondi ng to red,

green and bl ue. R od cells are responsibl e for interpreting di fferences o f

li ghtness (value) and cone cell s are responsibl e for int erpret ing t he

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General Review

Page 7

Sal eski 9 propos ed t hat an ideal li ght s ource for shade m at ching shoul d have the foll owing qualit ies:

(i) it should have com pl et e colour cont ent ,

(ii ) it should have enough int ensit y to overcome t he i nfl uence of

ambi ent room li ght and s hould s how sli ght as well as

dominant pi gment ati on in the t oot h,

(iii ) it should be com fort abl e to t he e ye to perceive colour

accurat el y and com fort abl y,

(iv) the li ght should be standard and shoul d be unchanging i n

qualit y and quantit y from da y to ni ght or season to s eason.

Several uncontroll ed factors such as fati gue, agi ng, em ot ion,

li ghting conditi ons and m et am eri sm can also affect color percepti on.

In t he cont ext of planning and performing dental t reatm ents,

estheti cs in general repres ents an i mportant out com e from pati ent’s

perspective, regardl ess of age 1 0. From this perspective the correct det ermination of tooth color can be considered crucial. Generall y, i n

the abs ence of an y visual impairm ent the color det ermi nation improves

over t ime1 1 t hrough t rai ning and exercise.1 2 , 1 3

Thus t he obs ervers must be t rained for col or di scrimi nat ion b y

repeat ed us e of st andard t ests as the abi lit y to distinguis h colors m a y

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Review of Literature

Page 8

M D RUSSELL et al (2000) 1 4 conduct ed a stud y and obs erved that teet h becom e li ght er when the y are dri ed. The pres ent st ud y

was desi gned to quantif y these changes and t ime t aken for t ooth

col or to return to normal. The color of an upper cent ral incisor in

each of seven subjects were m easured usi ng refl ectance

spect rophot ometer before and after appl ication of a rubber dam

and , in anot her s even subjects before and after taking a

pol yvin yl siloxane im pressi on. There were statist i call y si gnificant

changes i n the L, a and b values following rubber dam

applicati on and in L val ue foll owi ng impress ion t aki ng. The

results demonstrat e t hat t he t eeth becom e bri ght er and less color

saturat ed aft er rubber dam appli cation and bri ghter after

impress ion t aki ng. The ori ginal values were regained aft er 30

mins.

James C et al (2000) 1 5 conducted a stud y to evaluat e the C IE LAB, CM C (2: 1), and C MC (1: 1) formulas to identi f y which

provides the bes t i ndi cat or for accept abili t y of sm all color

differences in the estheti c dent al restorative m ateri als , to

det ermine i f di fferent groups of observers have di fferent l evels

of accept abi lit y, and to es timate t he color di fference t hat would

indi cat e accept abil it y bet ween a restoration and an adj acent

tooth. The subj ect popul ati on of hum an observers was di vided

into four groups , each cont aining 12 subjects. The composi tion

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Page 9

Group 2, denti sts; Group 3, dent al m at eri als sci entists; and

Group 4, pati e nts. A col or vision s creeni ng t est was admi nist ered

to each subject t o ensure t hat onl y obs ervers wit h norm al color

vision were evaluat ed. y. This test was com pos ed of six s et s of

discs fabri cated from dental composite resin restorat ive

mat eri al s. Each s et consist ed of one st andard dis c represent ing

tooth color. Color di fferences between t he st andard dis cs and the

restoration dis cs were cal cul at ed in C IELAB, CMC (1:1), and

CMC (2:1) color uni ts. In regard to the accept ance or rej ecti on

of dent al restoratio ns based onl y on col or di fference, the C MC

(1:1) color di fference form ula gives bett er correl ati on than t he

C IE LAB formula for smal l color differences in t he estheti c

dental rest orati ve m at eri als . There were si gni fi cant di fferences

found bet ween t he experi m ent groups i n regard to accept abi lit y

of col or di fferences using the CMC (1:1) and C IELAB formul as.

B y rej ecting sm all er color differences, the dent al auxiliaries

group proved to be more dis cri minating in accepti ng differences

bet ween toot h and composit e resin rest orative m at erial col or than

were pati ents . The mean 50:50 DE replacem ent poi nts for all

obs ervers were 2.29 and 2.72 color unit s for the CMC (,: c) and

C IE LAB form ulas, respectivel y.

RD Paravina et al (2002) 1 6 conducted a stud y to anal yze colo r paramet ers and col or compatibil it y of two randoml y chosen Vit a

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Page 10

In this st ud y the d at a were recorded usi ng a colorim et er s et to

standard illum inant source C and the C IE Lab s ys t em. A cus tom

adapt er s ys tem, whi ch all owed a m easuring area at the middle

third of the t abs , was produced. Each of 42 tabs was recorded

one tim e each on t hree di fferent da ys. Color dist ribution was

examined i n di agram s whose coordinates were L a b and L C H

col or coor dinat e pairs. Color difference ranges of Vit apan

Class ical and Vit apan 3D Mast er were 14.3 and 19.2,

respectivel y. It was concl uded t hat Compared t o Vit apan

Class ical, chrom ati cit y ranges of Vit apan 3D Mas ter were

extended in the desired di rect ions: hue w as ext ended toward

yell ow -red, and s at urat ion was extended toward more s aturated

tabs . C ompared to Vit apan Cl as si cal , Vit apan 3D M ast er tabs

were more uni forml y spaced. The exam ined shade guides were

found t o be color compati bl e

Steph en Ph el an (2002) 1 7, pres ent s a si ngl e onl a y cas e t hat was

si gni fi cantl y enhanced through a detai led comm uni cation process

bet ween the clini ci an and the l aborat ory t echni cian. B y us ing

col our slides as part of the dentist –techni cian communicat ion

process , t he author found tha t t he t echnici an was better abl e t o

creat e an est hetic, accurat e and success ful restoration that

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Page 11

Al ma dozi c et al (2003) 1 8 conduct ed a st ud y t o det ermi ne, quantit ativel y, the effect of di fferent thi cknes s ratios of opaque

porcel ain (OP) and transl ucent porcel ain (TP ) l a yers on the

overall s hade of all -cerami c specim ens . The C IE LAB values of 5

ass embled specimens, each consisting of 2 or 3 dis cs (C ORE

0.70 mm/ OP - 0, 0.25, 0.50, 0.75, or 1.00 m m/TP 1.00, 0.75,

0.50, 0.25, or 0 mm ) were det ermined with a s pect rophot om et er

for t he Vit a shades A1, A2, and A3. Dis tilled wat er was used to

att ain opti cal cont act between the l a yers. Bl ack or white

backgrounds were us ed to as sess the i nfl uence of the background

on the fi nal shade. Co lor differences (ΔE) bet ween l a yered

specim ens were det erm ined. C orrel ation between the t hicknes s

rat io and the L, a, and b values was cal cul at ed b y 2 -t ailed

Spearm an correl ation anal ys is. R esul ts i ndi cat ed t hat R edness a

and yell owness b i ncreas ed with th e t hickness of OP for all

shades. R edness a (P < .01 for all s hades ) correlat ed more strongl y with t hickness than yel lowness b (P < .01 for A1 and A3; P < .05 for A2). The li ghtness (L) was shade dependent. The correl ation (r) between OP/TP thi cknes s and L was 0.975 (P < .01) for s hade A1, 0.700 (not st atisti call y s i gni fi cant ) for s hade

A2, and 0.900 (P < .05) for shade A3. Thus it was concluded t hat Small changes i n thi ckness and shade of opaque and t ransl ucent

porcel ain l a yers can infl uence the fi nal shad e of the l a yered

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Page 12

F.D. Jarad et al(2005) 1 9 conduct ed a s tud y t o devel op a s hade mat ching m et hod bas ed on di gital im agi ng and t o com pare

obs ervers ' abilit y us ing thi s m ethod wit h the convent ional one

set agai nst a spect rophotomet ri c 'go ld standard'. Two Vit a Lumin

shade guides were used i n this st ud y, ni ne shades bei ng s el ect ed

from the fi rst Vit a Lumin shade guide, and the second s hade

guide was us ed t o mat ch t he sel ect ed s hades . A Nikon C oolpix

990 di git al cam era with Nikon SB21B ring fl ash was us ed to

record t he di git al i mages of the shade tabs of t he t wo s hade

guides and t he i mages were process ed using Adobe Phot os hop

soft ware. A tot al of 27 sampl es were mat ched wi th a di gital

shade guide prepared from the di git al im ages of the s econd shade

guide b y 10 obs ervers on a comput er screen. The obs erver‟s

shade m at ching performance was si gni ficantl y bett er with the

com put er met hod compared with t he conventional one. There was

a l arge vari ation in the obs erver ‟s m at ching abil it y. The di gi tal

camera can be us ed as a m eans of col our m easurements i n the

dental clini c.

Alvin G Wee et al (2006) 2 0 studi ed the accurac y of com merci al di git al camera for dent al appli cati ons . The y us ed t hree t ypes of

camera Nikon D100, Canon D60 and Si gm a SD9 cam era. Pict ures

were in raw format and they converted it into “TIFF” via the

converti ng software whi ch evaluat e d the C IE LAB val ues

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Page 13

concl uded that thes e cam eras when combi ned wit h the

appropri at e cali brati on protocol s shows pot enti al for us e in the

col or repli cation process of cl ini cal dent i st y.

Fund a Bayindi r et al (2007) 2 1 did a st ud y to det erm ine and to

com pare the coverage errors (CEs ) of 3 di fferent shades i n a

sel ected population. The coverage errors of the following s hade

guide s ys t ems were evaluat ed t o determine whi ch shade guide

s yst em is most effective in produci ng the best visual s hade

mat ch: (1) Vita Lum in, (2) Chrom as cop, (3) Vi tapan 3D M ast er,

and (4) a combination of t he 3 shade gui de s yst em s. The s pectral

refl ectance val ues of the central one ni nth (1 -mm di am et er) of

each shade t ab (witho ut a backing) were m easured wit h a

spect roradiom et er and an external li ght source at wavel engt hs

from 380 nm to 780 nm at 2 -nm i nt ervals. The col or values of

359 anterior t eeth were m easured with the s am e prot ocol. The

Vit apan 3D M ast er shade gui de s yst em result ed i n the l owest

coverage errors compared to the Vita Lumin or Chrom ascop

shade guide s yst ems . Coverage errors for the Vit apan 3D Mas ter

shade guide s yst em did not di ffer si gni fi cantl y from the coverage

errors when all 3 shade gui de s ys tem s were comb i ned.

Lars S chropp et al (2009) 2 2did a stud y to evaluat e the efficac y of di gital phot ographs and graphi c com put er soft ware for color

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Page 14

that Shade m at chi ng assi st ed b y di gi tal photographs and

com put er software was si gni fi cantl y more reli abl e than b y

conventional vi sual methods .

Jee-h a Choi et al (2010) 2 3 did a com parative stud y of vi sual and instrum ent al anal yses of shade select ion and concl uded t hat

the Overall , instrumental anal ys is i s more accurat e and

reproduci ble t han a visual ass essm ent, maki ng the difference

clini call y accept abl e.

Alpar Caglar & Kivanc Yaman el (2010) 2 4 did a stud y to evaluat e the color param et ers of composite and cerami c shade

guides whi ch were det ermined using a col orim et er and di gital

imagi ng wit h ill umi nants at different color t emperat ures . Two

different resin composit e s hade gui des , namel y Chari sma

(Heraeus Kulzer, Hanau, Germ an y) and P rem is e (Kerr

Corporati on, Orange, CA, US A), and two different cerami c shade

guides, Vit a Lumin Vacuum (V ITA Zahnfabrik, Bad S äcki ngen,

Germ an y) and Nori take (Noritake Co., Nago ya, J apan), were

evaluat ed at three di ffer ent colour tem perat ures (2,700 K, 2,700 –

6,500 K, and 6,500 K). Thi s stud y concl uded that di git al im agi ng

method coul d be an alt ernati ve for the col orim et ers unl es s the

proper object -cam era dist ance, di git al settings and suit abl e

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Page 15

Won-Suk Oh et al (2010) 2 5 did a st ud y to det ermine the vali dit y of the di git al photocol orim et ri c (PC M) method in mat ching the

col or of human t eeth. First, two Vitapan Class ical shade guides,

each cont aini ng 16 shade guide t eeth, were vi suall y s hade

mat ched, and di git al photographs of each three pai r of shade

guide t eeth were taken in a color m at chi ng booth. Secondl y,

visual shade m at chi ng of t he upper cent ral incisors of 48 s ubj ects

was perform ed b y t wo prosthodontist s independentl y i n a chai r,

using the Vit apan Classi cal shade gui de. The t hree closest shade

guide t eeth were visuall y select ed and ranked in order o f

preference, for whi ch di git al phot ographs were t aken un der

ceiling da yl i ght -corrected fluorescent li ghting. All di git al images

were anal yz ed on a com put er screen usi ng s oft ware t o cal culat e

the color di fference bet ween the reference toot h and other t eeth

in the s ame di git al image. The percent col or m at chi ng fo r the

shade guide t eeth and hum an t eeth was 88% and 75%,

respectivel y. There was no statisti call y si gni fi cant difference in

mat ching the t ooth col or bet ween the shade gui de t eeth and

hum an t eeth. The di gi tal PCM m ethod i s valid for t he range of

hum an t eeth bas ed on the Vit apan Cl as sical shade guide. This

method enhances communi cation with t he laborator y personnel in

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Page 16

Oi Hong Tung et al (2011) 2 6 conduct ed a stud y and hypothesized that different illuminants and camera‟s white

bal anc e s etups shall influence color rendering of di git al im ages

and affect the effectiveness of col or mat ching using di gital

images . Fi ft een ceramic disks of di fferent shades were fabri cated

and phot ographed wi th a di git al camera i n both autom ati c white

bal ance (AW B) and custom whit e balance (CW B) under ei ther

li ght -emitting diode ( LED) or el ect roni c ring fl ash. The

Commission Internationale d‟Éclairage L a b param et ers of the

captured im ages were derived from P hotos hop software and

served as di git al shade guide s . The y found a si gni ficantl y hi gh

correl ation coeffi ci ent (r2 > 0.96) between t he respect ive spect rophot ometer st andards and those shade guides generat ed in

CWB s etups. It was concl uded that t he reli abilit y of color

mat ches with di gi tal im ages is much i nfl uenced b y the

illuminant s and cameras white balance s etups, whil e di gi tal

shade gui des deri ved under LED i lluminant s wit h C WB

dem onst rate appli cabl e pot enti al in the fiel ds of col or

ass ess ment.

Fabiana Tak atsui et al (2012)2 7 did a st ud y to anal yze the color alt erati ons performed b y the C IE L a b s yst em in t he di gital

imagi ng of shade guide t abs, whi ch were obt ained

photographi call y accordi ng to the autom ati c and manual modes.

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Page 17

B3 and C4. An EOS Canon di git al cam era was us ed to record the

di git al im ages of the shade t abs , and the images were proces sed

using Adobe Photos hop software. A tot al of 80 obs ervat ions were

obt ained, leading t o color val ues of L, a an d b. The color

difference (∆E) between the modes were calculated and

cl assi fi ed as either clinicall y acceptable or unacceptable. It was

concl uded that the B1, B3 and C4 shade tabs can be used at an y

of the modes i n di git al cam era (manual or autom ati c), whi ch was

a di fferent fi nding from that obs erved for the A3.5 shade tab

whi ch demonstrat ed a clini call y unaccept abl e s hade.

W K T am et al (2012)2 8 conduct ed a stud y i n whi ch t he y

propos ed to compare the color of s hade tabs t aken b y a di gital

camera usi ng app ropri at e color features . Vit a 3D m as ter shade

guide and C anon EOS 1100D di git al cam era were emplo yed.

Shade t ab im ages were compared i n two reference s trat egi es . The

col or of tooth s urface was pres ented b y a content m anuall y

cropped out of the image. The c ontent was divided into 10*2

blocks t o encode t he col or dist ribution. Col or features from

comm onl y us ed color spaces were evaluated. The top n m atches

were sel ect ed when t he least n shade di st ances bet ween the shade

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Page 18

this stud y. Bot h the col or and t exture of the tooth surface could

be pres ent ed b y the proposed cont ent -based des cri ptor. Clini cal

use of di git al cameras in shade m at chi ng became possibl e.

Meh ta R et al (2014) 2 9 revi ewed on S hade s el ection -Bl ending of conventi onal and di git al m eth ods and inferred that the us e of

technology with di fferent devices in shade s el ection ma y

elimi nat e subj ectivit y of choosing and the use of photography to

comm uni cate shades and characteriz ations .

Karl glockner et al ( 2015) 3 0 conduct ed a stud y t o anal ys e the rel iabilit y of an Eas y Shade devi ce i n s hade selecti on com pared

to vis ual shade -m at chi ng m ethod. This stud y was based on the

examinati on of five hundred pati ent s of Dental Clini c Graz

Aust ri a. The s hade mat ching was obs erv ed in ri ght cent ral

maxillar y i nci sor (11), ri ght s econd m axillar y i ncisor (12) and

ri ght m axillar y caninus (13). The dat a obtained for both

experim ent al groups were anal yz ed usi ng the ANOVA t est . The

level of si gni fi can ce was set at 5%. Bas ed on thei r clinical

findings t he y concl uded that: both, t he visual and di git al t ested

methods were sim ilar accurat e in the shade determinati on. Bot h

methods in com bi nati on provide a good perform ance in

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Ralu ca Draghici et al (2015) 1 3 conduct ed a st ud y t o anal yz e the abili t y of dent al students t o visuall y as sess tooth color, b y the

usage of Vita 3D Mast er shade gui de, b y comparing thei r

mat ching to result s of an instrumental m ethod i .e., Vit a

Eas yS hade. S tudent s showed at a group l evel r el ative good

abili t y of vis uall y det ermini ng t he col or of the teeth, b y the

usage of 3D Mas ter s hade gui de.

Nakhaei M et al (2016)3 1 conduct ed a stud y to evaluat e the

infl uence of s hade guide t ype and professi onal experience

on s hade-m at chi ng resul ts and concluded t hat the t ype of

dental shade gui de affect ed t he shade -m atchi ng result s i .e. when

com pared wi th Vit apan Cl assi cal s hade guide, us e of the Vit apan

3D-M ast er shade gui de improves shade -m at ching results , als o the

level of experi ence was not found t o be an influent ial factor

in shade mat ching when 3D-Mas ter shade guide was us ed .

Dhru v An and et al (s ep 2016) 3 2 did a st ud y to as certai n if di git all y acqui red im ages wi th an S LR camera can be used as an

alt ernat ive to the VITA eas yshade spect rophotom et er for

obt aining the shade of the teeth. The y concluded that an S LR

camera with Adobe photoshop CS5.1 as an adjunct can be us ed as

an alternative to spectrophotometer in obtaining „l‟ and „b‟

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Vivek Pand ey et al (jun e 201 6 ) 3 3 conducted a st ud y to det ermine vali dit y of com bination of di git al photograph y and

conventional met hod of shade s el ect ion using s hade guide for

accurac y i n m atching colour of human t oot h over onl y

conventional met hod of shade sel ection. The y concl ude d that

whenever possi bl e, use both, as the y complem ent each ot her and

can l ead towards predi ct abl e estheti c outcom e. Thus wi thin the

limitat ions of this st ud y, tooth color mat chi ng usi ng the di gi tal

photograph y m ethod was found to be valid with t he us e of the

Vit apan Cl assi cal s hade guide. This digital technology could

provide an alt ernati ve accurat e as well as cost effect ive m ethod

of toot h color m at ching b y enhanci ng comm uni cation with the

laborator y personnel .

Ramin Negahdari et al in 2016 3 4 d id a com parative st ud y bet ween Vit apan cl assical and 3D mas ter shade guide s ys tems

and the conclusion was that t he repeat abilit y percent ages of

shade m atching in 3D Mast er s yst em was hi gh

Weng -kon g Tam in june 2017 3 5 conduct ed a stud y in which the y propos ed using support vector m achines (SVM ), which are

outst anding cl assi fi ers, i n shade classi fi cation. The y concluded

that sm artphone cameras, even thos e without int ernal set ting

feat ures, can be used as shade measuri ng i nstrum ents when an

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Page 21

reveal that t he proposed S VM cl assi fi cation mi ght out perform

the s hade -m at chi ng res ults of previous studies that have

perform ed si mil ar m easurements of Del t a E level s or us ed an S,

a*, b* feature s et.

Hoss ein Dash ti et al (2017) 3 6 st at ed t hat the proces s of disinfecti on and st erilization m a y change the col or of s hade t abs

and ul tim atel y affect shade -match procedure. The shade tabs t hat

were autocl aved s howed much greater color c hange than those

that were disi nfect ed

Juzer S. Miyajiwal a et al (2017)3 7 did a com parative stud y on 3

different m et hods us ed for shade sel ecti on, i.e., vi sual m ethod,

spect rophot ometer, and di git al phot ograph y m ethod and came to

a concl usion that t he di g it al phot ograph y m et hod em erged as

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Materials and Method

Page 22

MATE RI ALS- Sm artphone cam era (S am sung S9 plus) vit a 3D mast er shade guide, tri pod st and, gre y card, DS LR cam era(EOS C anon

1200D).

[image:34.595.125.478.193.529.2]

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METHO DOLO GY- A comm ercial shade gui de (3D mast e r vita shade guide, germ an y) is em plo yed in thi s stud y. The im ages o f t he

indivi dual shade t abs is capt ured using Samsung S9 plus s martphone

camera and DS LR canon EOS 1200D. The Shade t ab is pl aced over the

gre y card and t he s et up is pl aced i n an area with good nat ural sunli ght .

The posi tion i s adjus ted and t he li ght t em perature i s meas ured whi ch is

around 4000 - 5000 K. The cam era was mount ed on a tripod and a fixed

dist ance of 17cm was m aint ained bet ween the shade t ab and the

camera. A t ot al of 104 im ages are taken i.e, 2 photos for e ach of t he 26

shade t abs were taken both in sm artphone cam era and DS LR cam era.

Best im age was sel ected am ong t he 2 dependin g on the cl ari t y and

sharpness. The set tings of t he cam eras are described below : -

DSLR S ettings

 Im age was t aken wit hout fl as h

 Fixed shutt er speed 1/125s

 Autom at ed whit e bal ance

 Apert ure F/ 22

 T ype of met ering - m atrix

 IS O 100

 Fl ash mode - Off

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FI GURE : 3 – S et up of DSL R camera capturin g the i mage

[image:36.595.142.455.177.526.2]

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SMART PH ONE SE TTINGS

 Shutt er speed – Automati c

 Autom at ed whit e bal ance

 Apert ure was set at autom ati c mode

 IS O – aut om atic

 Fl ash mode – Off

 Fil e t ype – RAW and J peg im age

 T ype of met ering – mat rix, and the rest of the s ettings were in default/ aut omatic mode.

[image:37.595.148.454.351.639.2]

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The im ages b y sm art phone were captured in raw and j peg format

and b y di git al cam era was capt ured in raw format onl y. Raw fil e

pres erves most of t he inform ation from cam era, such as sharpness ,

contrast , wit hout processing and compressing . Thes e usuall y have l arge

fil e sizes and dis abl es m an y camera effects. When it com es to image

editi ng thes e are ver y versat ile and will los e no det ail s in further

editi ng or com pres s ion. J peg fil e is a comm onl y us ed and popular

image fil e form at, whi ch will be process ed and compress ed b y the

captured devi ce according t o the setting made b y t he us er.

As per Bengel W M (2003) 3 8 protocol t he following st ep -b y- step procedure i s to be followed :-

1. Aft er starti ng the Photoshop program, open the Windows@

(Mi crosoft ) Inform ation menu; this wi ll gi ve you the color

inform ation of each singl e pixel

2. Us e Ct rl + 0 to open the image to be anal yz ed

3. To eliminat e an overal l color cast, open the Levels di al ogue b y

pressi ng C TR L + L (or Image, t hen Adj ust, then Levels ). T hree

e ye-dropper tools wi ll appear. Sel ect the middl e one and move it

over the pi ece of gra y card i n the picture. Cli ck again to

elimi nat e the gl obal color cast of the im age. This can be

controlled b y checki ng the Informat ion panel: The R, G, and B

val ues , which woul d have been sl i ghtl y different before, will

now have the s am e value. The L a b values will have changed as

wel l: a : and b wi ll be set to 0; the L value will not have

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Page 27

4. Change t he color space from RGB to Lab. This has to be done for

L a b values to be recorded using t he hist ogram of Photoshop.

5. To obt ai n images wit h a comparable bri ghtnes s, im age bri ght ness

is com pared with a medi um value. The bri ghtness of an i mage is

express ed b y the L value.

6. The s el ected toot h will be surrounded b y a broken line on the

monitor. This li ne i ndi cat es t hat all m easurem ents refer onl y t o

the image cont ent wi thin t he line.

7. Reflecti ons on the tooth surface must be excluded.

8. L, a, and b values of the sel ected area are m et ered b y cli cki ng

Im age.

The L,a,b values of t he raw im ages of sm art phone were obt ained

using color l ab and that of DS LR cam era was obt ained us ing adobe

photoshop. The delt a E Values of sm artphone and DS LR in compari son

with t hat of th e m anufacturers shade t ab val ues were not ed us ing col or

lab C IE2000 soft ware. A s coring was gi ven for t he delt a E val ues i.e.

less than 2.5 is “not perceivable” and more than 2.5 is “perceivable” to

hum an e ye. Thi s was done becaus e the col or di fference bet ween 2

objects (delta E) of ˂ 2.5 is not discernible to human eye as suggested

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[image:40.595.92.518.237.477.2]

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FI GURE : 6 - S martphone i mage placed in Color L ab

[image:41.595.169.429.72.369.2] [image:41.595.166.431.417.705.2]

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Results

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In t his s tud y the L, a and b val ues were coll ected using DS LR

camera and sm artphone cam era [Tabl e 1]. For com paris on of shades

taken b y the 2 variables the s coring val ues were taken i nto account.

TABLE: 1 – L, a, b and del ta E Valu es of DSLR and s martphon e i mages

SHADE 3D MAST ER

MANU FA CT URE R

Lab V AL UES

DSL R SMART PH ON E

L* a * b * L 1 a 1 b 1 ^E L2 a 2 b 2 ^E

1M1

83.1 -0.1 12.5 84.3 0.7 14.1 1.6 82 0.5 15.2 1.8

1M2

84 -0.2 18.8 84.2 -0.6 21.8 1.2 83.9 0.6 14.6 2.5

2L1.5

79 0 18.5 76.5 2.6 20 3.4 80 1.9 17.4 2.5

2L2.5

79.5 0.2 24.5 77.2 1.2 23.4 1.9 84.1 1.1 18.6 4.3

2M1

78 0.8 14 79 3 13 3.0 78.4 3.2 14.6 2.9

2M2

78.7 0.9 19.9 79 1.7 24.6 2.3 81.8 2.2 15.3 3.7

2M3

79.2 0.7 25.3 79.3 1.4 25.6 0.6 80.0 3.2 25.1 2.4

2R1.5

77.8 1.5 16.3 77.1 5.6 16.7 4.7 80.1 2.7 16.1 2.1

2R2.5

79.5 1.7 23.3 80.6 2.6 25.9 1.6 79.2 3 21.2 1.8

3L1.5

73.1 1.5 20.3 75.4 2.8 18 2.6 73.4 3.5 18.9 2.4

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Results

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3M1

73.4 1.8 15.4 73.7 3.8 16.1 2.3 73 5.5 14.5 4.6

3M2

74.6 2 21.5 77.7 4.5 20.7 3.5 74.1 6.2 23.2 3.5

3M3

75 2.6 27.9 76.6 5.5 28.9 2.6 77.3 5.3 27.7 2.8

3R1.5

73.4 2.7 17.9 72.3 3.5 18.9 1.2 75.7 4.5 13.5 4.1

3R2.5

73.6 3.5 25.9 74.5 4.7 27.6 1.3 72.9 5.7 27.5 1.9

4L1.5

69.2 2.8 21.7 67.3 4.3 21.7 2.1 68.8 4.5 18.5 2.6

4L2.5

69.1 3.7 28.5 69.7 1.5 27.3 1.9 68.7 8.5 28.3 4.0

4M1

68.3 2.9 17.0 68.6 3.9 18.1 1.2 68.6 5.6 16.5 3.1

4M2

70.1 3.7 23.7 71.5 -0.7 29.2 4.9 71.7 8.8 23.8 4.8

4M3

69.5 4.8 30.7 70.01 3.9 30.4 0.8 64.6 8.9 21.9 3.3

4R1.5

69.6 4.3 20.8 68.4 4.2 23.9 1.8 69.4 5.7 17.6 2.6

4R2.5

69.2 5.1 26.3 68.8 5.4 29.9 1.6 68.2 7.9 27 2.4

5M1

64.4 4.2 19.4 70.1 3.7 18.5 4.5 64.8 7.0 20.6 3.3

5M2

65.1 5.7 26.3 67.6 5.3 26.6 2.0 68.9 7.9 26.9 3.4

5M3

65.9 7.0 33.4 67.4 4.6 25.8 3.6 73.3 7.1 33 5.75

Descript ive s tati sti cs is us ed to m eas ure t he variabl es. Bel ow i s t he

stati sti cal anal ysi s for t he 26 shades for the di fference between DS LR

and sm artphone phot ographs.

Table below shows the des criptive st ati stics of the change percent of

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Results

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TABLE: 2 DES CRI PT IVE STATIST ICS O F DSLR CAME RA

Mini mu m Maxi mu m Mean Std. Deviation

DS LR L1 change% -8.85 3.16 -0.818 2.51

DS LR a1 change% -500 800 -45.07 213.72

DS LR b1 change% -23.6 22.8 -3.65 10.39

DSLR ˄E 0.6 4.9 2.33 1.17

TABLE: 3 DES CRI PT IVE STATIS TICS O F S MARTPHONE

CAMERA

Mini mu m Maxi mu m Mean

Std. Deviation

SP L2 change% -11.23 7.05 -1.16 3.23

SP a2 change% -450 600 -77.19 202.03

SP b2 change% -21.6 28.7 5.26 12.04

SP˄E 1.80 5.75 3.10 1.01

INTERPRET ATIO N - Table 2 & tabl e 3 shows t hat the st andard deviation of “L” and “b” is more in smartphone camera than DSLR,

whereas standard deviation of “a” is more in DSLR than in

smartphone. However the ^E val ues of both the groups does not di ffer

much in st andard deviati on.

The change percent age of DS LR and Smartphone photographs for

[image:44.595.50.549.98.243.2]

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Results

Page 33

TABLE: 4

S H A D E 3 D MASTE R

DSLR L1

cha n g e %

D S LR a 1 chan g e %

D S LR b 1 chan ge %

SP L2

cha nge %

S P a2

chan ge %

S P b2

chan ge %

1M1 -1.44 800.0 -12.8 1.32 600.0 -21.6

1M2 -0.24 -200.0 -16.0 0.12 400.0 22.3

2 L1 .5 3.16 0.0 -8.1 -1.27 0.0 5.9

2 L2 .5 2.89 -500.0 4.5 -5.79 -450.0 24.1

2M1 -1.28 -275.0 7.1 -0.51 -300.0 -4.3

2M2 -0.38 -88.9 -23.6 -3.94 -144.4 23.1

2M3 -0.13 -100.0 -1.2 -1.01 -357.1 0.8

2 R 1 .5 0.90 -273.3 -2.5 -2.96 -80.0 1.2

2 R 2 .5 -1.38 -52.9 -11.2 0.38 -76.5 9.0

3 L1 .5 -3.15 -86.7 11.3 -0.41 -133.3 6.9

3 L2 .5 0.14 -142.1 0.8 -1.62 -115.8 0.0

3M1 -0.41 -111.1 -4.5 0.54 -205.6 5.8

3M2 -4.16 -125.0 3.7 0.67 -210.0 -7.9

3M3 -2.13 -111.5 -3.6 -3.07 -103.8 0.7

3 R 1 .5 1.50 -29.6 -5.6 -3.13 -66.7 24.6

3 R 2 .5 -1.22 -34.3 -6.6 0.95 -62.9 -6.2

4 L1 .5 2.75 -53.6 0.0 0.58 -60.7 14.7

4 L2 .5 -0.87 59.5 4.2 0.58 -129.7 0.7

4M1 -0.44 -34.5 -6.5 -0.44 -93.1 2.9

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Results

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4M3 -0.73 18.8 1.0 7.05 -85.4 28.7

4 R 1 .5 1.72 2.3 -14.9 0.29 -32.6 15.4

4 R 2 .5 0.58 -5.9 -13.7 1.45 -54.9 -2.7

5M1 -8.85 11.9 4.6 -0.62 -66.7 -6.2

5M2 -3.84 7.0 -1.1 -5.84 -38.6 -2.3

5M3 -2.28 34.3 22.8 -11.23 -1.4 1.2

INTERPRET ATIO N - Maximum change percent of DS LR and smartphone camera has been shown for variable “a”. Change percent is

more for “a” in lighter shades compared to darker shades. As per table

4, leas t change percent i s shown i n the vari abl e “ L” of DS LR camera

photographs.

The l ast and m ost key obj ect ive of the st ud y is to di fferenti at e between

the 2 vari abl es i .e. between t he Sm artphone and DS LR shade det ection

using Delt a E val ues .

So, t o com pare group 1wit h group 2 i nterventi ons , Wilcoxon si gned

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Results

[image:47.595.74.524.83.218.2]

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Table: 5

Descrip tive S tatisti cs

N Mean Std. Devi ation Minimum Maximum

DS LR ^E 26 2.331 1.1712 .6 4.9

SP ^E 26 3.1019 1.01474 1.80 5.75

INTERPRET ATIO N - The mean of DSLR ˄E and smartphone ˄E is 2.33 and 3.10 respectivel y. The m aximum st andard devi ation of DS LR

is 4.9 and minimum is 0.6 and for sm artphone maximum is 5.75 and

minimum is 1.80. The standard devi ation of bot h DS LR and s martphone

delt a E does not var y much.

Table:6

Ranks

N Mean R ank Sum of R anks

SP ^E – DS LR ^E

Negat ive

Ranks 7

a _9.07 _63.50

Positive R anks 18b 14.53 261.50

Ties ₁c

Tot al 26

a. SP ^E < DS LR ^ E

b. SP ^E > DS LR ^E

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Results

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Table: 7

Tes t S tatis ticsa

SP ^E - DS LR ^E

Z -2.665b

As ym p. Si g. (2 -t ail ed) .008

a. Wil coxon Si gned Ranks Tes t

b. Bas ed on negative ranks.

Interp retati on: Wil coxon s i gned rank test is perform ed between DS LR and Sm artphone photographs t o det ermine i f there is s igni ficant

difference for devi at ion (Delt a E) values.

The cal cul at ed t est s tatist i c val ue i n tabl e (Table: 5 ) i s les ser than the

cri tical value(p value) i.e. t here is signi ficant difference between t he amount of deviation of L,a and b val ues in DS LR and Smartphone photographs.

The val ue of p val ue is les ser than 0.05(0.008) [Tabl e7] which aids

rej ection of null h ypothesis, i.e. there is difference bet ween the am ount of devi ation of L, a and b values in DS LR and S martphone photographs. The sum of ranks shown i n Tabl e 6 s hows that positi ve sum of ranks has a hi gher value whi ch is Smart phone Delt a E values

[image:48.595.147.445.94.277.2]

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Results

Page 37

GRAPHS:

MEAN RANKS OF SP ^E - DSLR^E

0 2 4 6 8 10 12 14 16

NEGATIVE RANK POSITIVE RANK MEAN RANK 9.07 14.53

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Results

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MEAN OF SP^E AND DSLR^E

0 0.5 1 1.5 2 2.5 3 3.5

DSLR ^E SP ^E

2.331

3.1019

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Results

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The change p ercen tage of DSL R and S martph one ph otographs for

variabl es L , a and b from the manufacturing valu es

-600 -400 -200 0 200 400 600 800

1M1 1M2 _2L1.5 _2L2.5 2M1 2M2 2M3 _2R1.5 _2R2.5 _3L1.5 _3L2.5 3M1 3M2 3M3 _3R1.5 _3R2.5 _4L1.5 _4L2.5 4M1 4M2 4M3 _4R1.5 _4R2.5 5M1 5M2 5M3

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Discussion

Page 40

The form , functi on, and estheti cs in a restoration is of pri me

concern. Est het icall y pl easing restorati on depends on proper s hade

mat ching. Perfecti on in shade sel ecti on can onl y be achieved when the

prosthesis is an accurat e repli ca of the adj acent nat ural tooth. Shade

selection varies depending on the clinician‟s color perception and

experi ence, li ghti ng conditions, tooth background, and the shade guide

used. Communi cat ion with a dent al laborator y is another probl em as

the t echni ci an does not us ual l y s ee t he pati ent and has t o work on

dentist‟s written instructions.

To overcom e the di screpanci es of s hade sel ection , di gital

cameras were int roduced in dentist r y whi ch enabl ed cl i nici ans to

perform an objecti ve anal ysi s. A di git al phot ograph hel ps t o exactl y

repli cat e the col or of t he restorat ion due to i ts hi gh im age qualit y.

Wolfgang M et al in 2003 stated that a photographi c procedure using

di git al cam eras are propos ed t hat is relativel y simpl e and s uffi ci ent l y

precis e to allow t he ass essment of the t herapeuti c out com e of

tooth‐bl eaching procedures.4 0

As there is i ncreas e in preval ence of smartphones with high

resolution cameras, the photographs captured b y t his can be taken as

col or references in dent al shade mat ching. Because col or

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Discussion

Page 41

dentists and the laborator y techni ci ans who fabri cate dental

prosthes es.3 5

Wen- kong tam in 2016 3 5 conduct ed a stud y on dental shade mat ching b y using digital im ages that m a y be feasi ble when suit abl e

col or features are properl y m anipul ated . The y propos ed usi ng support

vector m achines (S VM), which are out standing cl ass ifi ers, in shade

cl assi fi cation. The y concluded that this stud y provides a feasibl e

techni que for dent al shade cl assificati on that us es t he camer a of a

mobil e device. The findings reveal that the proposed SVM

cl assi fi cation mi ght outperform t he shade -m at ching resul ts of previous

studi es t hat have perform ed simil arit y measurements of the levels or

used an s*, a*, b* feature s et.

Bas ed on P ubm ed an d Google s earch t his is the fi rst s tudy to

com pare the percei vabl e col or difference of v ita 3D mast er shade guide

tabs usi ng smart phone cam era and di git al cam era. Som e earli er studi es

com pared several di gi tal cam eras avail able at a point in ti me am ong

each other in order t o choose the best one for t elem edicine purpos es 4 2. Kodak V1s233 was chos en as provi ding t he best s olut ion. The Fuji F40

woul d serve well if a docking st ati on i s not needed. The Casio EX

-Z1200 is a good choice if t he us er can be trai ned to uti lize t he m acro

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Discussion

Page 42

Our st ud y des cri bes t he compari son of L,a , and b val ues of DS LR

images and sm artphone im ages with that of the m anufacturers

speci fi cat ions. The i mages were taken under cont rol l ed envi ronm ental

fact ors wit h 18% gre y card kept behi nd the shade t ab as clos e as

possi ble, whi ch is a neutral target as its red, blue and green val ues are

equal . Since t he gra y card had defi nit e values, t he software also

interprets it as gray, t hus el iminating the col or cast of the whol e

pict ure4 4. The im ages were in Raw form at as this is an uncompress ed fil e t ype wit h the m ost color inform ati on and is also easil y fixabl e if

the cam era sett ings were set wrong i niti all y. Edward A. Et al 4 5 stat ed that wit h an accurat el y and cons ist entl y expos ed i mage taken in R AW

format, and wi th the use of Whi Bal Gra y card and correctl y positioned

shade t abs, general practitioners can t ake a shade anal ys is i mage that

can be us ed to extract shade inform ation in photoshop usi ng t he Lab

and HS B color m odels. In t he aut hor‟s experi ence thi s has been

directl y us eful in choosing the correct s hades of ceramics for indi rect

restorations.

The dat a and anal ysis of t he st ud y s upport rej ecting t he null

h ypot hesis. In thi s st ud y it was det ermi ned that the subject effects were

stati sti cal l y s i gni fi cant.

The Vit apan 3D -M aster shade -m atching s yst em is used in this

stud y as it is extensi vel y use d in dent al clini cs and has been shown t o

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Discussion

Page 43

alone is j ust as effective as usi ng all 3 shade gui des com bined (VITA

Lumin, Chrom as cope & vit a 3D M ast er), which is l es s clini call y

practical . Since the L,a and b val ues would var y for each shade t ab, the

val ues gi ven b y spectroradiom et er was t aken as a cont rol group.

Del ta E is t he dist ance between 2 colors and is us ed to ens ure the

col our bei ng dis pla yed is reproduced wit h colour hue t hat m at ches so

closely to the colour input that the human eye can‟t perceive the

difference. The higher the value of Delta E (ΔE), shows that further

awa y the colour is from the t rue hue, us ing C IE LAB. Delta E of z ero

cannot be det ect ed using t he human e ye, thus i s t he perfect color value.

Few studies st at e t he mi nim al det ectab l e di fference is between 1 -2.5

Del ta E. A Delt a E between 3 and 6 is usuall y considered an accept able

number in comm erci al reproduct ion, but the colour di fference m a y b e

percei ved b y printi ng an d graphic profes sionals 4 6. There are few other studi es that s a y less than or equal to 1 is not perceptible b y human e ye,

1-2 will be percepti ble t hrough clos e observation and 2 -10 percepti bl e

at a glance.

In Table 4 it is shown that the change percent age of L

(lumi nosi t y of color) is l es s in DS LR when compared to sm art phone.

Out of t he 26 shade tabs hi gher DS LR change percent of L is visibl e i n

5 shades i.e 2L1.5, 3L1.5, 3M 2, 5M 1 and 5M2 shades . An acceptab l e

change percent of “a” in DSLR is in shade tab 4R1.5 and in smartphone

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Discussion

Page 44

Smartphone photographs to det ermi ne i f there is s i gni fi cant difference

for devi ati on (Del ta E) values .

The cal cul at ed te st stati sti c value i n t able (Table: 5) is lesser

than the criti cal value (p value) i.e. t here is si gnifi cant difference

bet ween the amount of devi ati on of L, a and b values in DS LR and Smartphone photographs.

Table 1 s hows the delta E values of DS LR and m anufact urers and

smartphone and m anufacturers. On t aking delt a E accept abl e value as

less than or equal to 2.5, shades 2L1.5, 2M1, 3L1.5, 2R1.5, 3M2, 3M3,

4M2, 5M 1 and 5M3 of DS LR cam era showed perceivabl e colo r

difference. The rest of the s hade tab have values t hat have no or barel y

percei vabl e col or di fference. Simil arl y smartphone delt a E shows no

col or difference in shade tabs 2 L2.5, 2M2, 3M1, 3M2, 3M 3, 3R1.5,

4L1.5, 4 L2.5, 4M1, 4M2, 4R1.5, 5M 1, 5M 2 and 5M3. Thus on

anal yzing tabl e 6 it can be st ated that 66% accurac y was obtained for

DS LR camera and 47% accurac y for sm artphone cam eras. On the other

hand i f delt a E val ue is t aken as less t han or equal to 2, s hades 2L1.5,

2M1, 2M 2, 2R1.5, 3L1. 5, 3L2.5, 3M1, 3M2, 3M3, 4L1.5, 4M2, 5M 1

AND 5M3 of DS LR camera and shades 1M2, 2 L1.5, 2 L2.5, 2M1, 2M 2,

2M3, 2R 1.5, 3L1.5, 3L2.5, 3M 1, 3M2, 3M3, 3R1.5, 4 L1.5, 4L2.5, 4M1,

4M2, 4R 1.5, 4R2.5, 5M1, 5M2 and 5M3 of smartphone cam era shows

col or di fference perce ptibl e at a gl ance. Thus , 50% accurac y is

obt ained for DS LR cam era and onl y 16% accurac y is obtained for

Comparison of Shade Selection by Smartphone Camera and DSLR Camera using Vita 3D Master Shade Guide: An Invitro Study