Correlation Between Caries Experience in Primary Molars and First Permanent Molars Among a Group of Egyptian Children: A Cross Sectional Study
Conditions: Caries,Dental
Sponsor: Cairo University

 
 
Correlation Between Caries Experience in Primary Molars and First 
Permanent Molars Among a Group of Egyptian Children: A Cross 
Sectional Study 
 
 
 
 
 
 
Submitted for partial fulfillment of the master requirements in Faculty of Dentistry 
Cairo university 
By 
Dema Abdelhameed theyab 
B.D.Sc. Faculty of Dentistry Modern Sciences and Arts University, 2012 
Under supervision of 
Dr.Amr Ezzat 
Associate Professor of Pediatric Dentistry & Dental Public Health Department of 
Dentistry/Cairo University 
 
Dr. Sara Ahmed Mohmoud 
Associate professor of Pediatric Dentistry & Dental Public Health, 
Department of Dentistry/Cairo University 
 
 
 
12/09/2018

 
 
Protocol Checklist 
Section and topic 
Item 
No. 
Checked item 
Reported 
on 
page 
NO.  
Reviewer’s 
check  
I. Administrative 
information 
 
 
1 
Title: PECOS elements included 
 
 
2 
Protocol registration 
 
 
3 
Protocol version 
 
 
4 
Funding 
 
 
5 
Roles and responsibilities of the 
authors 
 
 
 
II. Introduction 
 
 
6a 
Scientific background  
 
 
 
6b 
Specific objectives 
 
 
 
III. Methods 
A) 
Study 
design 
and settings 
7 
Study design  
 
 
8 
Settings  
 
 
B) Participants 
9a 
Eligibility criteria 
 
 
9b 
Methods of selection or case/control 
ascertainment 
 
 
9c 
Methods of follow up for cohort studies 
and rationale for choosing cases and 
controls for case control studies 
 
 
10 
Matched 
cohort 
study—matching 
criteria and allocation ratio (exposed: 
non-exposed) 
Matched 
case-control 
study— 
matching criteria and allocation ratio 
(case: control)  
 
 
C) Variables 
11 
Clearly define all variables including 
outcomes and exposures  
 
 
12 
For each variable of interest, give data 
sources/ measurement 
 
 
13 
Addressing potential sources of bias 
 
 
D) Study size 
14 
Study size 
 
 
E) 
Quantitative 
variables 
15 
Handling of quantitative variables in 
the analyses 
 
 

 
F) 
Statistical 
methods 
16a 
Statistical methods used to control for 
confounders 
 
 
16b 
Subgroup analyses 
 
 
16c 
Management of missing data 
 
 
16d 
Cohort 
study—If 
applicable, 
management of attrition bias 
Case-control 
study—If 
applicable, 
statistical method of matching 
Cross-sectional study—If applicable, 
analytical 
methods 
for 
different 
sampling strategies 
 
 
16e 
Sensitivity analyses 
 
 
 
IV- References  
 
 
References by reference manager 
 
 
 
Evidence based committee (Reviewers) 
 
Name 
Signature 
Date 
1. 
 
 
2. 
 
 
 
Research plan committee 
 
Name 
Signature 
Date 
1.  
 
 
2.  
 
 
 
 
 
 

1 
 
 
• Roles and responsibilities 
❖ Supervisors 
➢ Main Supervisor 
Dr. Amr Ezzat 
Associate Professor of Pediatric Dentistry & Dental Public Health, Department of Dentistry, 
Cairo University 
Role: 
• Reference for medical and evidential consultation for the study. 
• Supervising the protocol. 
• Supervising the thesis. 
• Regular monitoring on results and outcomes of the study. 
• Supervising the work done by the candidate on the participants. 
 
➢ Co-supervisor 
Dr. Sara Ahmed Mohmoud 
Associate professor of Pediatric Dentistry & Dental Public Health,  Department of Dentistry, 
Cairo University 
Role: 
• Supervising the protocol 
• Supervising the thesis. 
• Regular monitoring on results and outcomes of the study. 
• Dealing with participants in case of any negative feedback on the operator. 
• Supervising the work done by the candidate on the participants. 
 
 
 
 

2 
 
 
➢ Candidate: 
Dema Abdelhameed theyab 
B.D.Sc. Faculty of Dentistry Modern Sciences and Arts University, 2012. 
Role: 
• Formulating the protocol. 
• Choosing and grouping candidates for the study according to the eligibility criteria. 
• Explaining the aim of the study and providing verbal and written consents for the 
participants. 
• Preparing files for each participant, to include personal, medical, past and chief complaint 
histories 
• Oral examination  
• Recording the results and outcomes. 
• Formulating thesis. 
• Archiving of all the data harvested from the study and ensuring its privacy. 
• Providing statistician with all the information needed and collecting back statistical 
results. 
 
➢ Trial sponsor 
Pediatric Dentistry and Dental Public Health Department, Cairo University. 
The sponsor shall provide for the dental units for the research work. 
 
➢ Steering committees 
1. Department board. 
2. Research plan committee 
3. Evidence based committee, Faculty of DENTISRTY, Cairo University 
4. Ethics committee, Faculty of Oral and Dental Medicine Cairo University 
5. Higher education and research committee 
6. Faculty Board. 

3 
 
 
• Introduction 
The marked global raise in Dental caries reported in various countries over the last two 
decades urges the attention of researchers to investigate newer approaches and methods for 
its diagnoses, prevention, and treatment for this common health problem worldwide 
(MANDEL, 2017) 
Many researchers have reported that, the most critical period for the initiation and 
progression of occlusal carious lesions is at the time of eruption (Feather, 2000). At the age 
of 6 years, occlusal surfaces of the permanent first molars are particularly vulnerable to caries 
development (Welbury et al., 2004). Due to this many preventive strategies using sealants, 
fluoride varnish, and fluoride gel application was developed in an attempt to stop the caries 
progression. never less we need to categories the teeth which are at high risk for dental caries, 
several methods to identify children at increased risk of caries have been developed. These 
include bacterial and salivary tests in combination with oral hygiene scores and dietary 
factors. Those complicated prediction tests are considered time consuming and too costly for 
use in normal dental practice. 
On the other hand, Studies on caries risk assessment in children have shown that past caries 
experience is the best indicator of future caries development ,this Past caries experience is a 
simple and effective method, as to consider caries in permanent teeth to be a reflective mirror 
for the past caries experience in primary teeth , (Topaloglu-Ak & Eden, 2010).                               
 This study will investigate whether data of past caries experience of the primary molars of 6-
9 years old children can serve as an indicator for caries development in first permanent 
molars.as the first permanent molars is selected to represent the future caries status of the 
permanent dentition.  
 
 
 
 
 

4 
 
 
• Statement of the problem 
One of the main clinical scenarios a pediatric dentist may meet is to extract or do a root canal 
treatment for the first permanent molars at a young age, which may lead to a serious problem 
in the occlusion, given that the first permanent molar is the key of occlusion  ,many 
researches have been trying to investigate the underlying cause for the early decay of the first 
permanent molars including many expensive testes, all aiming to diagnose children at high 
risk for caries in permanent teeth , another controversy had suggest that caries in primary 
teeth is not only directly correlated to caries in permanent teeth, but also could be used as risk 
indicator for caries in first permanent molars, according to(Topaloglu-Ak & Eden, 2010), 
this study suggested the possibility of caries correlation between primary molars and first 
permanent molars, and that early preventive measures should be applied as early as possible 
in order to protect the first permanent molar from decay. But is this hypothesis reliable and is 
there a true correlation between caries in primary molars and first permanent molars? 
 
• Rationale 
➢ Importance of the study trial 
To detect the Relation between caries in primary molars and the development of caries in first 
permanent molars among Egyptian children. 
 
➢ Benefits of practitioners and clinicians 
If this study proves that there is a correlation between caries in primary and permanent molars, 
practitioners and clinicians will have an indirect benefit. Therefore, they can advise their 
patients on the importance of early caries-preventive measures. 
 
➢ Benefits to patient & Population 
Increase the awareness of importance of implementing oral hygiene and caries-preventive 
measures among patients and parents. 
 

5 
 
 
• Search Strategy 
The following databases were searched: 
▪ PubMed database.  
▪ Hand searching (Google scholars). 
Keywords used in both databases: 
▪ Primary and permanent molars  
▪ Dental caries, Early childhood caries, prevalence of caries 
▪ Children, preschool. 
 
• Inclusion Criteria 
Included articles should include all of the following criteria:  
▪ Studies applied on normal children. 
▪ Restricted to English language. 
▪ Association between caries in primary and permanent teeth 
 
• Exclusion criteria 
Articles will be excluded if they include one of the following criteria: 
▪ Other specialties. 
▪ Studies conducted upon adults 
▪ Studies conducted in languages other than English 
 
 
 
 
 
 
 

6 
 
 
 
• List of included articles 
Author and year 
Aim 
Characteristics 
Doneria et al. (2017) 
 
Comparative evaluation of 
caries status in primary and 
permanent molars in 7–8‐
year‐old schoolchildren of 
shimla using caries 
assessment spectrum and 
treatment index. 
 
-Cross-sectional study 
-Caries assessment in 
primary and permanent 
molars 
Baginsk et al. (2014) 
 
Dental caries in primary and 
permanent molars in 7-8-
year-old schoolchildren 
evaluated with Caries 
Assessment Spectrum and 
Treatment (CAST) index. 
-Cross-sectional 
-Aimed to examine caries in 
primary and permanent 
molars 
Topaloglu-Ak & Eden 
(2010) 
Caries in primary molars of 
6−7-year-old Turkish 
children as risk indicators 
for future caries 
development in permanent 
molars. 
-Cross-sectional 
 -Aim of study is to examine 
if past caries experience in 
primary molars can be used 
as a risk indicator for future 
caries experience in first 
permanent molars. 
 
Chen et al. (2003) 
 
Relationship of caries 
experience between primary 
teeth and the first permanent 
molars in 100 children of 6-
year-old. 
-Cross-sectional 
-Aimed to evaluate the 
association of caries 
between primary molars and 
first permanent molars. 
Wang et al., (2003) 
 
An eight-year longitudinal 
study for caries status on 
primary and permanent 
dentitions in Beijing 
children 
- Case report. 
- Aim of this study is to 
evaluate the caries status in 
primary and permanent 
dentition. 
Li and Wang (2002)  
Predicting caries in 
permanent teeth from caries 
in primary teeth: an eight-
year cohort study. 
- Cohort study. 
- The study aimed to 
examine the correlation 
between caries in primary 
and permanent dentition. 
Raadal and Espelid (1992) 
Caries prevalence in primary 
teeth as a predictor of early 
fissure caries in permanent 
first molars 
 
-Cross Sectional Study  
-The aim of this study is to 
evaluate whether caries in 
primary molars can be used 
as a predictor for early 

7 
 
fissure caries in first 
permanent molars. Fissure 
caries in first permanent 
molars. 
 
• List of excluded articles with reasons  
Author and date 
Aim 
Reason for exclusion 
Qiang and Zhi (2015) 
 
Caries status of the first 
permanent molar among 
6-7 years old and their 
correlation to caries in 
primary molars 
Study in Chinese language. 
 
 
• Review of literature 
Several studies reported that caries in primary teeth is correlated with caries in permanent teeth. 
A study by (Raadal & Espelid, 1992) aimed to examine the validity of employing the caries 
experience of primary dentition for predicting early fissure caries in the permanent first molar. 
192 children were examined, and after the children were grouped according to their dmft a 
statistically significant relationship was found between the dmft and the number of intact 
molars in each individual. It indicated that the dmft index of primary teeth should be used as 
an indicator for the use of preventive methods for fissure caries in permanent molars. 
Similarly, (Li & Wang, 2002) mentioned in their eight years cohort study, that aimed to 
determine if caries in primary dentition can predict caries in the permanent dentition of the 
same individual, that there were statistically significant associations between caries prevalence 
in primary and permanent dentition (p< 0.01). Children who had caries in their primary teeth 
had three times higher rate of developing caries in their permanent teeth with the permanent 
molar at highest risk, this concluded that caries in primary teeth could be used as a risk indicator 
for predicting caries in the permanent teeth. 
Furthermore, an eight-years longitudinal study was conducted by (Wang et al., 2003) to 
determine if the caries status in primary teeth can be used as a risk indicator for predicting 
caries in permanent teeth. A total of 362 children, 3-4 years old in the baseline study in 1992 
were reexamined in 2000 based on WHO criteria and methods, the result of this study found a 
significant association between the caries prevalence in primary teeth and permanent teeth 
(P<0.01) and between DMFT(s) and dmft(s) (P<0.01). Children who had caries in their primary 

8 
 
teeth were nearly three times more likely to have caries in their permanent teeth (RR=2.6.95% 
CI = 1.4-4.7, P<0.001). Therefore, this study concluded clearly that caries in the primary teeth 
can be used as a risk indicator for caries in permanent teeth. 
In addition, (Chen et al., 2003) examined a total of 100 school children 6 years old. The caries 
diagnosis criteria defined by WHO were employed. Fisher’s exact test showed that there was 
association between the caries experience of primary teeth and that of the first permanent 
molars in those children. The average dmft of primary teeth was in positive correlation with 
DMFT of the first permanent molars (r=0.5629). The results were statistically significant, 
concluding that the primary tooth caries experience may play an important role in predicting 
permanent tooth caries. 
Moreover, another study aimed to investigate whether the past caries experience in primary 
dentition can be tested to predict subsequent caries in first permanent molars. Clinical 
examinations were carried out in a school-based screening. 286 Turkish children aged 6-7 years 
old were examined and caries in the permanent first molars at the age of 10-11 years was then 
calculated. Caries experience of the primary dentition (dmft), primary molars (dmft molars), 
and primary second molars (dmft 2nd molars) showed a statistically significant correlation with 
caries (DMFT) 4 years later in the permanent first molars. Among the variables, the caries 
experience of the primary second molars was the most powerful caries predictor (Topaloglu-
Ak & Eden, 2010) 
 On the other hand, dental caries in primary and first permanent molars among 7-8 years old 
school children were evaluated using caries assessment spectrum and treatment (CAST) index. 
On the contrary to previous studies, this study found weak correlation between caries in 
primary molars and first permanent molars in the same jaw, while the correlation was found 
moderate in teeth situated in opposite jaws (Baginska et al., 2014) 
According to the study performed by (Doneria et al., 2017), caries was assessed in 6.3%-
12.3% of permanent molars in contrast to the primary molars, in which carries was near about 
50%. The correlation was stronger for first and second deciduous molars for the right side of 
the mouth than the left side (r=0.293 and 0.257 in the maxilla and 0.503 and 0.319 in the 
mandible [P<0.001]), respectively, while correlation for teeth in the opposite jaws was 
moderate [r=0.20-0.47], so it concluded that the correlation between first permanent molars 
and primary molars regarding the caries status were weak while strongest correlation was 
present on the right side of the mouth for first and second deciduous molars. 

9 
 
 
 
• Aim of the study 
 To investigate the correlation between caries experience in primary molars and first permanent 
molars, among a group of Egyptian children. 
• PICOS 
(P)Population: Egyptian children aged 6 to 9 years old with present primary molars and erupted 
first permanent molars 
 (O) Outcome: 
Outcome  
Outcome measuring  
Outcome measuring unit 
Primary Outcome: 
Caries experience in primary 
molars. 
Secondary outcome: 
Caries 
experience 
in 
first 
permanent molars. 
Numerical 
 
 
 
Numerical 
deft index 
 
 
 
DMFT index 
 
(S)Study design: Cross sectional study 
• Research question 
Is there a correlation between caries experience in primary molars and in the first permanent 
molars among a group of Egyptian children? 
 
• Hypothesis 
This research adopts null hypothesis; it assumes that there is no correlation between caries 
experience in primary molars and first permanent molars. 

10 
 
 
 
 
• Participants and methods 
➢ Ethics 
▪ All the procedures will be explained to the parents or guardians prior to the investigation. 
▪ An informed consent will be signed by the parents (Appendix 1) 
▪ Study design: cross sectional study design. 
 
➢ Setting & Location 
 Data for this particular study will be collected from the clinic of Pediatric Dentistry and dental 
public health Department, Faculty of Dentistry, Cairo University. 
➢ Participants 
▪ Eligibility criteria  
o Inclusion criteria 
1. Children ages from six to nine years  
2. Both sexes. 
3. Parent and children cooperation. 
4. Healthy children. 
5. Children with sound and carious primary molars and erupted all of the first permanent 
molars. 
 
o Exclusion criteria 
1. Children age under 6 or more than 9 years. 
2. Children had a complex metabolic or medical disorder. 
3. Parents that will not sign the consent. 
4. Children with missing or unerupted first permanent molars. 

11 
 
 
 
 
➢ Variables 
To control other confounders for caries, additional independent variables will be considered 
including: 
• Gender. 
• Number between siblings. 
• Only child. 
• Socioeconomic status. 
• Oral hygiene.  
• Type of toothpaste used. 
 
 
 
 
 
 
 
 
 
 
 
 
 

12 
 
 
 
• Data and sources measurements 
➢ Methods 
▪ Clinical examination will be carried out while the child is sitting on dental unit, using 
sterile diagnostic set (mirror and explorer) in daylight. No diagnostic radiographs will 
be taken. 
 
▪ A custom-made examination chart will be filled for each child including date, name, 
age, address, gender, medical history and previous dental treatment. Parents data 
includes: level of education and oral hygiene level. 
 
 
▪ Prior to performing dental examination, the child will be asked to rinse his mouth with 
tap water and the teeth will be cleaned with sterile cotton. 
 
▪ The examiner will carefully inspect all surfaces of the teeth, for proper diagnosis, the 
teeth were dried thoroughly with an air syringe. It will be important to see clearly and 
to use the air syringe to distinguish readily cervical or interproximal caries. 
 
 
▪ All the primary teeth will be evaluated using deft index and permanent teeth will be 
evaluated using DMF index, both according to WHO criteria. 
 (WHO, 2003) criteria: 
➢ Clinical caries lesion shows the following criteria 
 
▪ Lesion in pit or fissure, or on a smooth tooth surface with cavitated undermined 
enamel, or a detectably softened floor or wall.  
▪ Teeth with recurrent dental caries. 
▪ In cases where the crown has been destroyed by caries and only the root is left, the 
caries is judged to be crown caries. 
 
➢ Lesions not considered as clinical dental caries 
 
▪ White or chalky spots (early carious lesion). 
▪ Stained enamel pits or fissures without visible cavitation or soft floor or walls during 
examination by sharp explorer. 
▪ Dark, shiny, hard, pitted areas of enamel in a tooth showing signs of moderate to 
severe enamel fluorosis. 
▪ Each child and parents will be given two printed sheet translated into Arabic, after the 
end of the diagnosis, which will include his/her caries status, the right oral hygiene 
method to be followed in order to maintain a good oral health status and any caries 

13 
 
lesions that need treatment by restorative material or preventive measures (Appendix 
4). 
 
• Bias 
Possible bias that can occur: 
▪ Selection bias: can be avoided by including all the children fulfilling the inclusion criteria. 
▪ Reporting Bias: All outcomes will be reported. 
▪ Detection Bias: All outcomes will be detected.  
 
• Diagnostic chart: (Appendix:1) 
 
• Sample size calculation 
Sample size will be determined by the Evidence-Based Dentistry committee in the faculty of 
Dentistry, Cairo University. 
 
• Statistical methods 
Statistical analysis will be done using statistical package for social sciences, version 21.0 
(SPSS, IBM) for windows. 
 
 

14 
 
• References 
Baginska, J., Rodakowska, E., Milewski, R. & Kierklo, A. (2014) Dental caries in primary 
and permanent molars in 7-8-year-old schoolchildren evaluated with Caries Assessment 
Spectrum and Treatment (CAST) index. BMC Oral Health, 14 (1), p.74. Available from: 
<https://doi.org/10.1186/1472-6831-14-74>. 
Chen, X., Liu, H. & Liu, S. (2003) [Relationship of caries experience between primary teeth 
and the first permanent  molars in 100 children of 6-year-old]. Shanghai kou qiang yi xue = 
Shanghai journal of stomatology, 12 (1), pp.14–15. 
Doneria, D., Thakur, S., Singhal, P., Chauhan, D., Jayam, C. & Uppal, A. (2017) 
Comparative Evaluation of Caries Status in Primary and Permanent Molars in 7–8-year-old 
Schoolchildren of Shimla Using Caries Assessment Spectrum and Treatment Index. 
Contemporary Clinical Dentistry, 8 (1), pp.128–133. Available from: 
<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5426145/>. 
Featherstone, J. D. (2000). The science and practice of caries prevention. The Journal of the 
American dental association, 131(7), 887-899. 
Herzog, K., Scott, J.M., Hujoel, P. & Seminario, A.L. (2016) Association of vitamin D and 
dental caries in children: Findings from the National Health and Nutrition Examination 
Survey, 2005-2006. Journal of the American Dental Association (1939), 147 (6), pp.413–
420. 
Li, Y. & Wang, W. (2002) Predicting caries in permanent teeth from caries in primary teeth: 
an eight-year  cohort study. Journal of dental research, 81 (8), pp.561–566. 
MANDEL, I.D. (2017) Caries prevention: Current Strategies, New Directions. The Journal of 
the American Dental Association, 127 (10), pp.1477–1488. Available from: 
<http://dx.doi.org/10.14219/jada.archive.1996.0057>. 
Raadal, M. & Espelid, I. (1992) Caries prevalence in primary teeth as a predictor of early 
fissure caries in permanent first molars. Community Dentistry and Oral Epidemiology, 20 (1), 
pp.30–34. Available from: <http://doi.wiley.com/10.1111/j.1600-0528.1992.tb00669.x> 
[Accessed 21 December 2017]. 
Topaloglu-Ak, A. & Eden, E. (2010) Caries in primary molars of 6&#x2013;7-year-old 
Turkish children as risk indicators for future caries development in permanent molars. 
Journal of Dental Sciences, 5 (3), pp.150–155. Available from: 
<http://dx.doi.org/10.1016/S1991-7902(10)60022-0>. 
Welbury, R., Raadal, M., & Lygidakis, N. A. (2004). EAPD guidelines for the use of pit and       
fissure sealants. European Journal of Paediatric Dentistry, 5, 179-184. 
World Health Organization (2003). Continuous improvement of oral health in the 21st 
century – the approach of the WHO Global Oral Health Programme from 
http://www.who.int/oral_health/media/en/orh_report03_en.pdf 
 

15 
 
 
 
 
• Appendix (1) : 
Examination chart 
 
Date: 
 
Patient Name:                                               Age:                     Gander: 
 
Address:       
 
Medical history:       
 
Parents level of education: 
 
 
 
 
Dental history: 
• Soft tissue examination…… 
• Hard tissue examination: 
 
 
E 
D 
C 
B 
A 
A 
B 
C 
D 
E 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
E 
D 
C 
B 
A 
A 
B 
C 
D 
E 
 
 
 
8 
7 
6 
5 
4 
3 
2 
1 
1 
2 
3 
4 
5 
6 
7 
8 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
8 
7 
6 
5 
4 
3 
2 
1 
1 
2 
3 
4 
5 
6 
7 
8 
  
 
D=……,     M=……….  , F=………….                DMFT=……. 
 
d=…….   ,  e=…………. , f=………….                  deft=……..  
 

16 
 
 
 
 
• Appendix (2): 
 
➢ How to Clean Your Teeth: 
 
➢ How to protect Your teeth from Caries: