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Transcript of Caries indices
1. An Index can be defined as a numerical value describing the
relative status of a population on a graduated scale with definite
upper and lower limits, which is designed to permit and facilitate
comparison with other populations classified by the same criteria
and methods.
(Russal A. L)
2. An Index is an expression of clinical observation in numerical
values which is used to describe the status of the individual or
group with respect to a condition being measured.
(Wilkins Esther M.)
3. Dental Index is an abbreviated measurement of the amount or
condition of disease in a population; a numerical scale with a
defined upper and lower limits designed to permit and facilitate
comparison with other population classified by the same criterion
and methods.
(Zarkowski Pamela)
4. Epidemiologic Indices are attempts to quantitate clinical
conditions on a graduated scale, thereby facilitating comparison
among populations examined by the same criterion and methods.
(Glickman Irving)
1. To increase understanding of the disease process.
2. To discover populations at high and low risk.
3. To define specific problem under investigation.
1. Clarity, Simplicity and Objectivity
2. Validity
3. Reliability
4. Quantifiability
5. Sensitivity
6. Acceptability
Reversible
•Measures the conditions that can be changed•Indices for periodontal conditions
Irreversible
•Measures the conditions that will not change.•Dental caries index
A. Depending upon the directions in which
the scores can fluctuate
Full Mouth
•Measures patient’s entire periodontium or dentition•Russel’s Periodontal index
Simplified
•Measures only a representative sample of dental apparatus•Greene and Vermillion’s oral hygiene index-Simplified
B. Depending upon the extent to which areas of
oral cavity are measured
D. Special Category Indices
Simple Index
•Measures the presence or absence of a condition.•Index measuring presence of dental plaque without an evaluation of its effect on gingiva.
Cumulative Index
•Measures all the evidence of a condition, past and present.•DMF index for dental caries
It is a dyanamic process of demineralisation due to microbial metabolism resulting in
net mineral loss which subsequently may not always lead to cavitation
Frejeskov
1997
DENTAL CARIES
Dental caries is an irreversible microbial disease of calcified
tissues of the teeth, characterised by demineraliasation of the
inorganic portion and destruction of the organic substance of the
tooth, which often leads to cavitation
SHAFER’S
HISTORICAL BACKGROUND OF CARIES INDICES.
BODECKER CF and BODECKER HWC
• described a Caries Index in 1931
• Modified it later by addition to counting of decayed surfaces.
DEAN HT
• Counting carious teeth visibly in the mouth
MELLANBY M
• In 1934 described the carious lesions depending upon the degree of severity
• 1 = Slight caries• 2 = Moderate caries • 3 = Advanced caries
• First systematic description - DMF index
• Attributed to Knutson JW, Henry Klein and Carole Palmer in their studies of dental
caries in Hagerstown and Maryland (1930)
FINALLY….
MOST COMMONLY USED OTHER MIXED DENTITION INDICES
DMFT
1. Primary Teeth (dmft & dmfs)
2. Permanent Teeth (DMFT &
DMFS)
1. Stone’s Index
2. Caries Severity Index
3. Czechoslovakian Index
4. Caries Susceptibility Index
5. Modified DMFT Index
6. Functional Measure Index
7. Tissue Health Index
8. Dental Health Index
9. DMFS Percentage Index
10.Moller’s Index
11.Restorative Index
12.Significant Caries Index
INDICES FOR DENTAL CARIES
DIAGNOSING PIT AND FISSURE CARIES : -CRITERIA
ANGLO-SAXON SYSTEM {LIBERAL}By Horowitz H.S. In 1972
The pits and fissure on the occlusal, vestibular and lingual surfaces are carious when-1 The explorer “catches” after insertion with moderate to firm pressure . 2. When the catch is accompanied by one or more of the following signs of decay a) Softness at the base of the area. b) Opacity adjacent to the area provides evidence of undermining or demineralization. c) Softened enamel that can be scraped by explorer.
NOTE : - Areas should be diagnosed as soundwhen there is apparent evidence of demineralisation but no evidence of softness.
DIAGNOSING PIT AND FISSURE CARIES : -CRITERIA
“EUROPEAN SYSTEM {CONSERVATIVE} By Backer-Dirks O., Houwink B., Kwant G.W. in 1961
Teeth are first dried and sharp new explorers are used
• Upper molars : Mesio-occlusal and disto-occlusal-palative fissures are assessed separately.
• Lower molars : Occlusal fissures and buccal pits are assessed separately.
C I - Minute black line at the base of fissure C II - In addition, a white zone along margins of fissure. C III - Smallest precipitable break in the continuity of enamel. C IV - Large cavity, more than 3mm wide.
SOME OTHER IMPORTANT INDICES
1. Root Caries Index (RCI)2. Dental Caries Severity Index For Primary Teeth
DECAYED-MISSING-
FIILED TEETH INDEX
(DMFT INDEX)
Henry T. Klein, Carrole E.
Palmer and Knutson JW in
1938
• Developed to determine the prevalence of coronal caries.
• Is a simple, rapid, versatile, universally accepted and widely used index for several
decades.
• It is used to determine total dental caries experience past and previous.
• The DMFT Index is an irreversible index (meaning that it measures total lifetime caries
experience).
• The tooth either remains decayed or if treated it is extracted or filled.
Procedure • The DMFT Index is applied only to permanent teeth is composed of three components.
DMFT Index
D Decayed M Missing FFilled.
Examination of DMFT Index has to be done with : -
1. Favorable lighting conditions
2. A No. 3 plain mirror
3. A Fine-pointed pig-tail explorer
Third molars and Unerupted teeth
Congenitally, missing and
supernumerary teeth
Teeth removed for reasons other than dental caries
Teeth restored for reasons other
than dental caries
• All 28 teeth are examined.
Teeth not to be included
Principles and Rules in recording DMFT: 1. No tooth must be counted more than once. It is either decayed, missing, filled or sound.
2. Decayed, missing, and filled teeth should be recorded separately since the components of
DMF are of great interest.
3. When counting the number of decayed teeth, also include those teeth which have
restorations with recurrent decay.
4. Care must be taken to list as missing only those teeth which have been lost due to decay.
5. Also included should be those teeth which are so badly, decayed that they are indicated for
extraction.
The following should not be counted as missing:
a) Unerupted teeth
b) Missing teeth due to accident
c) Congenitally missing teeth
d) Teeth that have been extracted for orthodontic reasons.
6. A tooth may have several restorations but it is counted as one tooth.
7. Deciduous teeth are not included in DMF count.
8. A tooth is considered to be erupted when the occlusal surface or incisal edge is totally,
exposed or can be exposed by gently, reflecting the overlying gingival tissue with the mirror or
explorer.
9. A tooth is considered to be present even though the crown has been destroyed and only the
roots are left.
WHO modification of DMF Index (1986)
1. All third molars are included.
2. Temporary restorations are considered as decayed
3. Only, carious cavities are considered as ‘D', the initial lesions (Chalky spots. stained fissures,
etc) are not considered as ‘D'. The DMF Index can be applied to denote the number of
affected teeth (DMFT) or to measure the surfaces affected by dental caries (DMFS).
CODING CRITERIA FOR DMF INDEX:CODE
For tooth absent , ‘O’ Missing Tooth - unerupted , impacted , congenitally missing. ‘X’ Extracted permanent tooth.
E Excluded tooth or tooth space
1 Sound permanent tooth
2 Filled permanent tooth
3 Decayed permanent tooth
Calculation of the IndexIndividual DMFT: total D+M+F= DMF.
Group Average: Total DMF Total number of the subjects examined
Percent Needing Care Total number of decayed tooth
Total number examined
Percentage of teeth lost: Total number of missing teeth Total number examined
Percent of filled teeth : Total number of filled teeth Total DMFT
Missing permanent teeth/100 Total number of missing teeth X 100 Total number examined
The maximum possible
DMFT score is 32 ( if third molars are included )
DMFT score is 28 ( if third molars are excluded)
Advantages of DMFT index 1. Because of its wide spread use world wide over the past 60 years , it provides a
reasonably accurate historical account of changes in prevalence of dental caries.
Limitations of DMFT Index:1.DMFT values are not related to the number of teeth at risk.
2. DMFT index can be invalid in older adults because teeth can become lost for reasons other
than caries.
3. DMFT index can be misleading in children whose teeth have been
lost due to the orthodontic reasons.
4. DMFT index can over estimate caries experience in teeth in which
"preventive fillings" have been placed.
5. DMFT Index is of little use in studies of root caries.
I. WORLD HEALTH ORGANISATION (WHO) has described a shorthand method
1. Recommends the use of "half-mouth" DMF in its basic survey techniques. 2 Objective is to obtain assessments of caries prevalence in a population
which has not been previously surveyed. 3. Half the upper arch only is scored. then the contra lateral lower half arch
and the results doubled. It is Quicker and easier than full-mouth DMF Index.
DECAYED - MISSING -
FILLED TOOTH SURFACES
INDEX (DMFS) Henry T. Klein, Carrole. E.
Palmer and Knutson J.W in
1938.
More sensitive
Usually the index of choice in a clinical trial of caries preventive agent.
Used to determine total dental caries experience past and present by recording tooth surface
invloved instead of teeth.
• DMFS is a more detailed index than the DMFT by summing the total number of decayed.
missing and filled permanent tooth surfaces.
• As in the case of the DMFT Index, the DMFS index is simple and versatile and more sensitive,
has practically, universal acceptance. and is one of the best-known dental indices today.
DMFS Index - The Index of
ChoiceThis is because relative incidence is more likely to be detected
over the limited time period of a clinical trial.
But a DMFS examination takes a longer is more likely to produce
inconsistencies in diagnosis and may require the use of
radiographs to be fully accurate
1. For Posterior teeth: Five surfaces examined and recorded: facial, lingual Mesial, distal and occlusal
2. For Anterior teeth: Four surfaces examined and recorded: facial, Lingual, mesial and distal.
Calculation of DMFS Index:1. Individual DMFS Index : DMFS score = D+M+F
2. Total surface count for a DMFS Index
(If 28 teeth are examined)
• 16 posterior teeth (16*5=80)• 12 Anterior teeth (12*4=48)• Total= 128 surfaces
3. Total surface count for a DMFS Index
(If 32 teeth are examined)
• If third molars are included (4*5)=20surfaces
• Total = 128 + 20 = 148 surfaces
Established modification:• Procedural modifications can be made to the DMFS index to allow for factors such
as secondary caries , crowned teeth , bridge pontics , and any other particular
attribute required for study .
• To save time in large surveys, the DMFS can be used half-mouth , applied to
opposite diagonal quadrants and the score doubled an approach that assumes
that caries incidence is bilateral.
Disadvantages
1. DMFS examination takes a longer time and is more likely to produce inconsistencies in
diagnosis and may require the use of radiographs to be fully accurate.
To save time in larger surveys, the DMFS can be used half- mouth , applied to opposite
diagonal quadrants and the score doubled .
This is based on the assumption that caries incidence is bilateral
2. A tooth scores exactly the same under extremes of clinical conditions; a tooth with small
restoration in one pit rates the same as a tooth that has been extracted.
3. Provides little or no additional information in prevalence studies where the extent of caries
is being compared between groups.
4. Has a wide range of possible values and hence a larger standard deviation and standard
error.
5. One of the difficulties encountered in use of this surface index is the score to be allocated
to teeth indicated for extraction, which may have been attacked on one surface only,
although its extraction results in the loss of four or five surfaces , according to the tooth.
6. Another difficulty is the score to be given to two surface fillings in posterior teeth, where
the initial attack was probably on one proximal surface and the occlusal surface was
involved later, to provide an adequate class II type of cavity or restoration.
The Caries Indices used for primary dentition are 'deft' index and 'defs' index equivalent to the
DMFT and DMFS indices used for permanent dentition.
def Index
d decayed e extracted ffilled.
The basic principles and rules for def index are the same as that for DMF index.
‘d’ decayed
Indicates the number of deciduous teeth that are decayed. In counting the number of decayed
deciduous teeth - a tooth can only be counted once.
It cannot be counted as filled and decayed. If it has been restored and caries can be detected
count it as decayed.
The explorer should fall into carious tooth substance and not just in a deep groove before
counting occlusal caries.
'e' extraction Indicates those deciduous teeth which have been extracted due to caries or which are so
badly, decayed that they are indicated for extraction. Because of the wide variation in the
time of exfoliation of deciduous teeth.
It is difficult to determine whether a tooth missing from the deciduous dentition was normal,
exfoliated or was extracted because of advanced caries.
If it can be accurately established that a missing deciduous tooth has been lost due to caries.
include it with those indicated for extraction
‘f’ filled Indicates the number of deciduous teeth that have been attacked by caries but which
have been restored without a recurrent decay present.
A tooth may have several fillings but it is counted as one tooth. If a tooth has a filling
but shows evidence of recurrent decay.
It is counted as a decayed tooth.
Modifications of def index
dmf index
For use in children before ages of exfoliation i.e. children over 7 years and upto 11 or 12
years
df index
In this index the missing teeth are ignored. df index can be applied –
to whole tooth as : decayed –filled- tooth (dft index) or
to individual surfaces as : decayed filled surfaces (dfs index)
Disadvantages (def and dmf indices)
1. It is difficult to determine whether the primary tooth has been extracted or shed
naturally, by this index.
• The D1-D3 Scale was first published by WHO in 1979 as an aid to diagnosing
coronal caries.
• Traditionally used among European investigators who diagnose dental caries from
the earliest detectable non-cavitated lesion through to pulpal involvement ,said to
be of extreme value in research studies because it permits identification of lesion
progression as well as initiation.
• Involves a lengthy & detailed examination, requires meticulous examiner training
DENTAL CARIES SEVERITY CLASSIFICATION SCALE
0-surface sound : no evidence of treated or untreated clinical caries.
D1-initial caries : no clinically detectable loss of substance For pits & fissures, there may be
significant staining, discolouration, rough spots in the enamel that do not catch the explorer
but loss of substance cannot be positively diagnosed.
D2-Enamel caries : demonstrable loss of tooth substance in pits, fissures or on smooth
surfaces, but no softened floor or wall or undermined enamel. The texture of the material
within the cavity may be chalky or crumbly, but there is no evidence that cavitation has
penetrated the dentin.
• D3-caries of dentin : detectably softened floor, undermined enamel or a softened wall, or
the tooth has a temporary filling. On proximal surfaces, the explorer point must enter a
lesion with certainty
• D4-pulpal involvement : deep cavity with probable pulpal involvement. pulp should not
be probed (usually included with D3 in data analysis)
Score Criteria
1 One point to one or more cavities in the same tooth detectable by sharp probe where the lesion has not penetrated through the enamel to involve the dentine.
2 Two points to one or more cavities in the same tooth where the dentine is involved, where a total of less than a Quarter of the crown is estimated to have been destroyed
3 Three points to one or more cavities in the same tooth resulting in a total destruction of more than a Quarter of the crown
Scoring Criteria
a. This index was developed to study the depth and extent of the caries surfaces and the extent
of pulpal involvements.
b. The progress of the dental caries in stages as described by Massier and Schour in 1952
were modified and this caries severity index was devised to measure the extent and depth of
decayed surfaces and pulpal involvements based on clinical and radiographic examinations.
Score Criteria
1 Superficial (caries in enamel)
2 Moderate (caries in enamel and superficial dentine)
3 Moderately severe (enamel undermined)
4 Severe (approaching pulp,enamel,collapsed)
5 Pulpitis(caused either by deep seated caries or by trauma without caries)
6 Death of pulp (caused either by deep seated caries or by trauma without caries)
7 Periapical infection (caused either by deep seated caries or by trauma without caries)
Scoring Criteria
• This index is mainly used to compare caries experience in one group with that of the other
groups with a similar population density but living in different environments.
• In this index the "variables" seems to be controlled. In all examination studies and tests in
which this index is used, the average number of teeth, tooth surfaces and tooth areas and the
condition of previously extracted or crowned teeth were considered.
The proposed formula can be applied as a basis for an individual or a collective index.
In individual examination. the "Base" is given by the amount of teeth in adult dentition (32)
and in collective studies, the "Base" is the number of persons examined multipled by 32 to
establish the correct base figure. The average index value will then be between 0 to I. The
nearer, the index is to 1 the higher the caries frequency.
The following formula serves as the basis for this caries index (in adults):
1- C - FC - 4/ 5 E - 2 / 3 AT Base (C- Caries: FC - Fillings and Crowns; E Extractions; and AT - Anchorage teeth).
1. This index is based on Bodecker and Mellanby caries indices.
2. There are 2 factors involved in measuring caries susceptibility using the dynamic
survey, namely
a) Amount of tooth surface at risk.
b) Amount of caries developing during the period of observation.
Method:• Each tooth is divided into various surfaces, to use one caries tooth surface as the unit of
measurement.
Susceptible surfaces are scored as follows:
• Incisors - Mesial. Distal. Lingual. labial = 4
• Canine - Mesial, Distal, lingual, labial = 4
• Premolar - Mesial, Distal, Lingual. Buccal Occlusal = 5
• Molar - Mesial, Distal, Lingual. Buccal, Occlusal = 5
Full permanent dentition thus would have 148 susceptible surfaces and full deciduous dentition
would have 88 susceptible surfaces.
Method : All the teeth are given surface values (SV)
-The incisors and canines are given ‘four’ values.
-The premolars and molars are given ‘five’ values.
1. Deciduous and permanent teeth are treated alike and a mixed dentition does not upset this
index.
2. Caries teeth are allotted ‘ONE’ carious surface value (CSV) for every surface attacked by
caries.
3. Missing teeth are allotted equivalent to their total surface values (missing teeth lost other
than caries are not included).
4. Restored teeth are treated as carious teeth.
5. Inter proximal cavities of incisors are given 3 (CSV) values and of premolars and molars are
given 2 (CSV)
In the suggested DMFS percentage index:
• The age of the subject is considered,since different numbers of surfaces are present at
different ages
• The simplified age factors for different age groups are as follows:
AGE AGE FACTOR
6 to 71/2 months 6
7 to 9 months 3
12 to 14 months 2
16 to 18 months 1.5
20 months to 5 years 1
6 to 11 years 0.9
12 to 16 years 0.8
17 years 0.7
• Calculation:
To determine the DMFS percentage caries index of an individual, total the carious
surface values and multiply by the age factor for the particular individuals age
group.
a) RI=F/F+D
b) Measures the proportion of attached teeth(F+D) which are filled(F)
c) Does not depend on DMF index & hence can be used at all ages
d) RI is not a weighted index,it is a simple proportion with a definite meaning
e) It is the objective of the unmet restorative treatment needs (UTN) used by Glick et al in
1972,which is D/F+D%
f) The restorative index as a community index:
The RI can be used to measure the level of restorative care in any community and for any
subsection of a community at any age
DMFT index by Klein and Palmer Is simple and most widely used in epidemiological surveys of dental caries
It quantifies dental health status based on the number of decayed missing and filled teeth.
Drawbacks of DMFT index Does not provide an accurate description of previous dental care.
Does not provide information regarding severity of carious attack or the indicated
treatment.
To overcome these drawbacks of DMFT index the modified DMFT index was developed.
• Basically this modified DMFT index involves the same operational procedures as common
DMFT index. The only difference is in the scoring criteria for ‘D’ component of index , which
is divided into 4 separate categories as follows : -
• C = Unfilled teeth that are carious
• CF = Teeth that are carious around the margins of restorations or primarily on a tooth
surface other than restored one.
• IX - Carious teeth either filled or unfilled that in the examiners opinion are indicated for
extraction
• IRC - Carious teeth either filled or unfilled that in the examiners opinion are indicated for
pulp treatment or RCT.
• Advantages1. The index remains simple and yet provides description of previous dental experience.
2. It further shows the extent of dental services needed by the population, which can be
interpreted in terms of treatment hours and costs.
3. In addition to these four categories, the remaining two categories of DMFT index (F- filled
teeth with no decay and M- Missing teeth) are recorded as usual according to the WHO
criteria.
4. The DMFT score is then, the summation of all six categories and the calculation of the
individual components as well as sum remains essentially the same as the original DMFT
index.
METHOD• Caries seen on the buccal,lingual and palatal surfaces or proximal caries is only scored for
these surfaces when normal pits or fissures of these surfaces are affected or included, or
when the caries extends along atleast half the gingival third of these surfaces
• Only the largest caries involment is scored for any one surface. Scores of two or more lesions
on one surface are not combined
• A filled surface is given a score of “1”, secondary caries at the margin of restoration is given a
score of “2”
• A full crown restoration gives a total score of 5 for that tooth and the total tooth score of 6 is
given to a tooth extracted because of caries.
• These scores are based on the clinical experience of the earlier levels of caries severity
resulting in these types of treatment
• Score for each tooth is total of the scores of all the surfaces
• Although a theoretical score of 15 is possible for molars and 12 for canines and incisors,
part of the tooth material loss may have occurred because of fracture of unsupported
surface, rather than caries of that surface.
A ) Occlusal surfaces & pit and fissure caries on buccal or palatal surfaces of
molars:
1 -
2 -
3 -
early pit and fissure caries where explorer catches or resists removal with moderate or firm pressure, and is accompanied by either a softness at the base of the areas or an opacity adjacent to the pit or fissure as evidence of undermining or demineralization or softened enamel adjacent to the pit or fissure which may be scraped away with the explorer.
cavitation of atleast 1mm across the smallest diameter at the tooth surface
cavitation with breakdown or undermining (as seen by obvious discolouration) of atleast half a cusp
B) Buccal,lingual and palatal smooth caries
1 a white lesion not extending to the embrasure areas,found to be soft and sticky by penetration with the explorer
2 cavitation of atleast 1mm but less than 2mm across the smallest diameter, or a soft sticky white lesion extending into one embrassure
3 cavitation of atleast 2mm in the smallest diameter or a soft sticky white lesion extending into both embrasures
C) Proximal surfaces of molars:
1 a discontinuity of the enamel in which an explorer will catch and there is softness
2 cavitation with early breakdown of marginal ridge or obvious discolouration indicating undermining of the ridge
3 breakdown of the marginal ridge with cavitation extending to mesial or dental extensions of occlusal fissures
D. Proximal surfaces on incisors and canine
1 a discontinuity of the enamel in which an explorer will catch and if there is softness
2 cavitation with breakdown or obvious discolouration, indicating undermining for atleast 1mm on the buccal or lingual surfaces
3 cavitation with breakdown of incisal edge or undermining of the edge is indicated by obvious discolouration
• Thus a maximum of 12 is scored for molars and a maximum of 9 for canines and
incisors
• If caries has resulted in complete breakdown of the crown,leaving only roots,the
maximum score is recorded for this tooth
• The CSI for the population is the mean of the scores for the caries teeth.Teeth free
of caries are not included in this calculation.
Advantages 1. The basis for the development of this system was to make available a system which could
be used in many different situations .
2. It is flexible in meeting the various needs of different types of clinical studies on dental caries.
3. The diagnostic criteria are specified for
* pit and fissure surfaces
* smooth surfaces
* radiographic evaluation of proximal surfaces
4. Untreated carious lesions are divided into 4 types Type 1 ,2,3,4 which makes it possible to
exclude certain types of carious lesions in either diagnosis or during the analysis.
RECENT ADVANCES
1. Tissue Health Index
2. Dental Health Index
3. Oral Health Status Index
4. Functional Measure Index
1.Oral health status index
Marcus M, Koch AL, Gershen JA in 1980.
The index includes – 3 component of DMFT and 15 other variables such as –
• Temperomandiular dysfunction,• Degree of periodontal disease and• Tumors.
2. Functional measure index
Sheiham A, Maizels J, and Maizels A in 1987
FIRST ALTERNATIVE TO DMFT
Definition-
Is defined as the aggregate of healthy restored (i.e filled) teeth (otherwise sound)
and sound teeth with no decay.
Was the first composite indictor index to measure dental health and functional
status rather than disease.
In FMI the filled and sound teeth are weighted equally, while the decayed and the
missing teeth are given zero weight .
Formula- FMI = Filled + Sound 28The FMI score ranges from - 0 to 1
Advantage Disadvantage
1. More reliable indicator of dental health status than conventional DMFT
2. More efficient at revealing the antecedent and behavioural facts that are associated with dental health status.
1. Very little research can be found utilizing this index.
2. According to some it is a sound approach to measuring dental health and function rather than the disease hat probably deserves more attention.
3. Tissue Health Index Was Sheiham A, Maizels J and Maizels A in 1987 second alternative to DMFT index.
Definition - defined as the weighted average of decayed teeth, filled (other
wise sound) teeth and sound teeth.
Purpose - To assess dental health status rather than dental disease in relation to
caries.
Principle The weights represents the relative amount of sound tissue surrounding these
three categories of teeth. that means-
• Sound teeth contains- more sound tissue
• Filled tooth contains – more sound tissue compared to decayed tooth.
• Missing tooth – contains no sound tissue
• In THI selective weights are given to the 3 components as follows
1 – Decayed
2- Filled
4- Sound
Formula to calculate THI
THI = 1/4( 1X decayed + 2 X filled + 4X sound) 28
Third molars are not considered.
Advantages1. More reliable indicator of dental health than the conventional DMFT.
2. More efficient at revealing the preliminary and behavioural factors that are associated
with the dental health status.
For example-
categories of decayed, filled and missing teeth are each assigned equal weights to derive
DMFT score.
3. So the transformation of decayed tooth into a filled tooth by restoration has no effect on
the DMF value.
4. In addition, the DMF value, specifically the number of filled teeth, distorts the
disease experience score of those who have regular dental checkups and who
observe a preventive approach to their dental health.
4. Dental Health Index (DHI)
Carpay JJ , Nieman FHM, Konig KJ, Felling AJ and Lammers JGM in 1988.
This index uses selected teeth for developing the index.
Any number of teeth may be examined and the denominator is adjusted
accordingly.
This index was developed to minimize the difference between sound and
affected (or extracted )teeth .
• Formula-
DHI = (Sound teeth)- (decayed +filled+ missing teeth) Sound+ decayed+ filled+ missing teeth
DHI – is the ratio of sound teeth minus unsound teeth divided by the total number of teeth examined.
• SCORE
Sound teeth given score of +1 Affected (extracted teeth) of - 1
1. This was to make the simple prevalence measures for root caries more specific by including
the concept of teeth at risk for root caries.
2. This index is specifically designed for analytical epidemiological studies in which risk factors
and causes of diseases are being studied.
3. This index can be computed for an individual, for a particular tooth types, or for a population
at large.
4. An RCI of 7% means that all of the teeth with gingival recession, 7% were decayed or filed on
the root surface.
Procedure:
To obtain the RCI each of the four surfaces the mesial, distal, buccal (labial), and lingual of a
root are examined for a single tooth.
All teeth are examined in both the lower and upper arch.
It is the suggested rule that when multiple root surfaces are exposed, the most severely
affected root surface be recorded for that tooth even though this occurrence is judged to be
rare.
A designation of missing (M) is made for the whole tooth and not for a single surface.
The root surfaces are characterized and recorded as missing
M
Showing no association with gingival recession
NoR
Recession present, surface decayed R-D
Recession present, surface filled R-F
Recession present, surface normal or sound
R-N
• Therefore, once a tooth is observed to be missing, all the root surfaces are recorded as
missing.
• A judgement of no recession (NoR) is made if the cemento-enamel junction (CEJ) cannot be
observed.
• In addition, if calculus is present in the absence of any other findings on a recessed root
surface. a judgement of sound (R-N) is made on the assumption that decay is not found
underneath the band of calculus.
• Once the above information is collected and recorded, as illustrated in the following formula,
the RCI is obtained by adding the number of root lesions and restorations and dividing that
number by number of root surfaces with gingival recession in decayed. filled, and sound
teeth.
• The data collected is entered on a format for each tooth examined, as given below:
M D B L
R-N
R-F
R-D
NOR
108
• The columns represent four surfaces: M Mesial. D-Distal. B- Buccal. L- lingual.
• The rows represent the conditions that could occur on the surfaces:
R-N = Recession present; surface normal Or sound
R-D= Recession present: with a decayed root surface
R-F = Recession present; with a filled root surface
NoR=No association with gingival recession
Diagnostic conventions proposed for RCI
Ralph V Katz in 1986 presented the following conventions for RCI
• Convention Number 1 : If the diagnosis of caries or of filled is uncertain, score the
surface as 'sound'.
• Convention Number 2 : All caries detected on root surfaces near the Cemento-Enamel
Junction (CEJ) shall be scored as 'decayed' regardless of the adjacent enamel condition.
• Convention Number 3 : For any coronal filling which extends on to a root surface, the
filling material must extend more than 3 mm, beyond the CEJ in order to score that root
surface as 'Filled' (exception: cast crowns extending on to a root surface are never
recorded as filled for that root surface).
• Convention Number 4 :
In order to score a filling as involving multiple surfaces, the filling must extend
across at least 1/3 rd of each additional surface.
• Convention Number 5a : Recurrent decay associated with a fOot surface
filling should be recorded as an independent disease category called
"Recurrent Root Decay“
• Convention Number 5b :
Recurrent decay associated with a coronal filling (i.e. a coronal filling extending less
than 3 mm onto the root surface) or a crown should be recorded as an
independent disease category called "Root Decay Contiguous with Coronal Filling".
• Convention Number 6 :
For any root surface that is decayed. the events of an additional but
separate root lesion is recorded as an independent disease category
called" Additional Root Caries Lesion".
In order to use the ICDAS criteria in epidemiological surveys the following conditions are essential to enable examiners to assess each of the caries codes accurately: overhead operating light; cleaned teeth and compressed air. The ICDAS codes can be used to examine cleaned teeth in other conditions but the data recorded this way is unlikely to be comparable with other ICDAS examinations. Variation from the ideal conditions detailed above will compromise the sensitivity of the examination, e.g. without compressed air many code 1 lesions cannot be detected and should be omitted from the code list. It is suggested that if compressed air is unavailable the following codes should be used: [insert new ICDAS epi codes which use letters rather than numbers to highlight that the codes are not comparable with full ICDAS]. Explanation to the table Column 1: Terms of increasing severity stages of caries for lay personsColumn 2: Terms for the visual apperance for increasing severity stages of caries for professionalsColumn 3 Related scores to coulmn 2Column 4: Activity assessment posibilities for the scores in column 3 and thus also columns 2 and 1Column 5: Scores for radiographical classification of lesion severity: 0=no radiolucency 1= radiolucency in outer ½ of the enamel 2= radiolucency in inner ½ of the enamel± EDJ 3= radiolucency limited to the outer 1/3 of dentine 4= radiolucency reaching the middle 1/3 of dentine 5= radiolucency reaching the inner 1/3 of dentine, clinically cavitated 6= radiolucency into the pulp, clinically cavitated
Column 6: Scores for Fibre-optic translumination (FOTI); classification of lesion severity: Proximal and occlusal 0= no shadow or stained area 1= Lesion stays the same width when transilluminated/Thin grey shadow into enamel when transilluminated 2= Wide grey shadow into enamel when transilluminated 3= Wide grey shadow into enamel with no evidence of dentine shadow 4= Orange/brown or bluish/black shadow < 2mm in width 5= Shadow as described above and/or transillumination light is blocked > 2mm in width 6= Large area of frank cavitation with likely pulpal involvemen
All sites were visually examined by two investigators (doctoral student calibrated by an experienced investigator) using the International Caries Detection and Assessment System (ICDAS-II) [14] and a consensus score for each site was achieved. The chosen sites were recorded as: 0 = sound ( = 1 3); 1 = first visible sign of noncavitated lesion seen only when the tooth is 𝑛dried; 2 = visible noncavitated lesion seen when wet and dry; 3 = microcavitation in enamel; 4 = noncavitated lesion extending into dentine seen as an undermining shadow; 5 = small cavitated lesion with visible dentine: less than 50% of surface; 6 = large cavitated lesions with visible dentine in more than 50% of the surface
EXAMINATION TYPESThe four different types of dental examinations arediscussed in the paragraphs that follow. To ensureuniformity in nomenclature and definitions, dentalexaminations are classified by type.
TYPE 1, COMPREHENSIVEEXAMINATIONThis is the ideal examination, for it is the mostextensive dental examination. The dentist will performa comprehensive hard and soft tissue examination thatincludes: oral cancer screening examination; mouth-mirror, explorer, and periodontal probe examination;adequate natural or artificial illumination; pano-graphic or full-mouth periapical, and posteriorbitewing radiographs; blood pressure recording; andwhen indicated, percussive, thermal and electrical test,transillumination, and study models. Included arethose lengthy clinical evaluations required to establisha complex clinical diagnosis and the formulation of atotal treatment plan. For example: treatment planningfor full-mouth reconstruction; determination of theetiology or differential diagnosis of a patient's chiefcomplaint, such as temporomandibular joint (TMJ)dysfunction and associated oral facial pain; or lengthyhistory taking relative to determining a diagnosis, orin-processing examination for officer candidates
TYPE 2, ORAL EXAMINATIONComprehensive hard and soft tissue
examination,which will include: oral cancer screening examination;mouth-mirror, explorer, and periodontal probeexamination; adequate natural or artificial illu-mination; appropriate panographic or intraoralradiographs as indicated by the clinical examination;and blood pressure recording. An appropriatetreatment plan will be recorded. This type is theroutine examination, which is normally done only onetime per treatment regimen per patient, unlesscircumstances warrant another complete examination
..TYPE 3, OTHER EXAMINATIONThis examination consists of
diagnosticprocedures as appropriate for: consultation betweenstaff or staff residents; observation where no formalconsult is prepared; certain categories of physica examinations; and emergency oral examinations forevaluation of pain, infection, trauma, or defectiverestorations.
TYPE 4, SCREENING EVALUATIONThis type of examination consists of a mouth-mirror and explorer or tongue depressor examinationwith whatever illumination is available. This categoryincludes the initial dental processing of recruitswithout necessarily being examined by a dentist orother screening procedures. A qualified dentalassistant or dental hygienist may perform a type 4examination