6.Brief Resume of Intended Work

6.BRIEF RESUME OF INTENDED WORK:

6.1Need for the study:

Dental caries is a major oral health problem across various countries. The prevalence of dental caries in India is 31.5-89%1 which indicates it to be a major public health problem posing a great challenge to dental professionals. There is overwhelming evidence to support association between sugar consumption and dental caries. Earlier studies state that the amount and frequency of sugar intake are influenced by the life style of the people but according to recent research it’s due to individual genetic differences in sensitivity to taste perception.2Taste worlds of humans vary because of taste blindness to 6-n-propylthiouracil [PROP]. Sensitivity to PROP is inherited.3

PROP is a medication used in the treatment of Grave’s disease. PROP can be tasted at very low concentration of 1.6mg.PROP is safe to use in both children and adults to assess the genetic sensitivity to bitter taste.4 The subset of the population who rate PROP paper as intensely bitter are identified as supertasters. Supertasters generally perceive taste at lower concentration as compared to medium and non-tasters and thus generally show ambivalence to foods with high concentration of these taste qualities, where as non-tasters tend to prefer them. This may influence their consumption of refined sugars which in turn has implication on the causation of dental caries.

To tackle dental caries, prevention seems to be the best panacea. Determining caries risk factors is very important before planning preventive programs. Caries activity tests play a pivotal role in assessing the caries risk of the patients. Although caries activity tests are more detailed and give reliable results, majority of the tests are cumbersome, expensive and time consuming. On the other hand PROP test is easily applicable, quick, less expensive and safe. With recently few studies stating a significant negative relationship between PROP sensitivity and caries experience5it calls for research in this area. A relative paucity of studies that compare caries experience and PROP sensitivity has driven us to conduct study in this regard. Hence the present study aims at assessing the dental caries experience among students with different genetic sensitivity to bitter taste of 6-n-propylthiouracil.

Research question

Is there a difference in dental caries experience among 15 year old school students in Davangere city with different genetic sensitivity to bitter taste of 6-n-propylthiouracil?

6.2 Review of literature

A study was conducted to assess the prevalence of dental caries in children with different genetic sensitivity levels to bitter taste of 6-n-propylthiouracil where in majority of non-tasters were sweet likers and preferred strong tasting food products while majority of supertasters were sweet dislikers and preferred weak tastes. There was significant increase in overall caries experience in population, as genetic ability to detect PROP taste decreased [r (correlation value)=-0.41, p<0.001].5

In Mangalore, a study among 500 children belonging to age group of 8-12 years of both sexes was undertaken to determine the relationship between body mass index, dietary preferences, caries experience with taste sensitivity to 6-N-Propylthiouracil. Sensitivity to PROP test, body mass index, caries experiences were recorded along with their history of dietary habits. The results were subjected to analysis using Analysis Of Variance [ANOVA] test and chi-square test. The results showed that supertasters had significantly low caries experience [Decayed Missing Filled Surface Index (DMFS) 1.06] compared to non-tasters [DMFS 3.63].6

A cross sectional survey was conducted among 181 children, aged 12 years, from rural and urban areas of Brazil to assess if sensitivity to bitter taste and sweet taste had an influence on dental caries experience. Sensitivity to bitter taste was assessed using propylthiouracil and sweet taste using sucrose. Bitter non-tasters had higher caries experience. A positive correlation was observed between sensitivity to bitter taste and sweet taste perception among children in the rural(r=0.42, p=0.002) and urban areas (r=0.36, p=0.001).7

To assess the relationship between PROP sensitivity and caries activity in school children using cariogram a study was conducted. 120 students between ages 7-12 years were investigated. Based on decayed filled surface index (dfs) under cariogram, the sensitivity of cariogram and PROP tests were 0.85 and 0.70 respectively and specificity 0.32 and 0.33 respectively. PROP non-tasters were significantly at high risk of dental caries than PROP tasters (p<0.01).2

6.3 Objectives of the study:

1.  To assess the caries experience among 15 year old school students in Davangere city.

2.  To assess the sensitivity to the bitter taste of PROP among 15 year old school students in Davangere city.

3.  To compare the caries experience among different tasters as detected by PROP test among 15 year old school students in Davangere city.

4.  To assess the relationship between caries experience and PROP sensitivity among 15 year old school students in Davangere city.

5.  To assess the relationship between PROP test and caries activity test among 15 year old school students in Davangere city.

7. MATERIALS AND METHODS:

7.1 Source of data

Study population: 15 year old school students in Davangere city will constitute the study population.

Study setting: School setting

Study design: A cross sectional survey

7.2 Sample size determination:

The sample size is 150 subjects. The sample size was decided based on earlier studies by Oter B et al. where a significant difference between the caries experience was observed between taster group and non-tastergroup.2

Sample size is determined based on the formula,

n=2t2 s 2/d2

Where, n=sample size of each group.

t=2.13 (theoretical value of ‘t’ distribution with 95% confidence interval)

s=2.6 DMFT (pooled standard deviation observed in previous study) 2

d=1.2 DMFT (minimum expected difference in DMFT between supertasters observed in previous study) 2

n=2x (2.13)2x(2.6)2/(1.2)2=43 (sample size in each group)

Since the present study considers three groups, the sample size will be

Sample size=43x3=129

The sample size of 129 subjects was rounded off to 150 subjects.

Sampling Methodology:

For the administrative purpose Davangere city is divided into four zones (North-east, South-east, North-west, South-west). From each zone, one school will be selected randomly and from each school, students aged 15 years who fulfil the selection criteria will be randomly selected. Quota sampling technique will be employed to obtain a minimum of 50 subjects in each group.

SELECTION CRITERIA:

Inclusion criteria:

1.  15 year old school students studying in Davangere city.

Exclusion criteria:

1.  Subjects suffering from systemic diseases or/on long term/recent/current regimen of medication that can affect taste perception.

2.  Subjects with known allergy/ history of adverse reactions to propylthiouracil.

3.  Subjects with acute dental distress, requiring emergency dental treatment.

4.  Subjects undergoing orthodontic treatment.

Method of data collection:

·  Ethical clearance:

The synopsis of the study will be prepared and submitted to the Institutional Review Board of Bapuji Dental College and Hospital, Davangere for ethical clearance.

·  Permission to select, examine and collect the relevant data from the college students will be obtained from the respective degree college authorities.

·  Informed consent:

Voluntary written informed consent will be obtained from the parents of the subjects and assent from the study subjects after they read the patient information form which explains the procedures involved in the study. The copy of the patient information form and informed consent form is hereby enclosed.

·  With the help of self-designed and pretested proforma, the data will be collected regarding socio-demographic profile, dietary habits and oral hygiene practices.

·  Oral hygiene status, dental caries experience, PROP test results and results of caries activity tests will be recorded in the proforma.

·  Oral hygiene will be assessed using Oral Hygiene Index- Simplified given by John C. Greene and Jack R. Vermillion in 1964.8

·  Caries experience will be assessed according to the WHO (1997) criterion using DMFT and DMFS index developed by Henry T. Klein, Carrole E. Palmer and Knutson J.W.9

·  Taste sensitivity will be investigated using PROP paper based on PROP test criteria.2

·  Investigation of Caries activity will be done by ‘Streptococcus mutans count test’.10

·  PROP test and oral examination will be conducted at the college premises.

·  Oral examination will be done by seating the subjects on an ordinary chair with a back rest under available natural light with aseptic precautions within the college premises.

·  All the examinations will be performed by a single examiner who will be calibrated against the Benchmark (faculty) and also calibrated to minimize intra-examiner variability.

·  Microbiological analysis will be conducted by a trained oral microbiologist.

Statistical analysis:

The data will be compiled systematically in Microsoft Excel spread sheet and subjected to statistical analysis using SPSS version. Significance level will be set at α=5%.

·  Comparison of caries experience (continuous variable) among different tasters will be done using one way ANOVA and if significant difference is observed then it will be followed by Tukey’s-HSD post hoc test.

·  Assessment of correlation between caries experience (ordinal data) and PROP sensitivity (ordinal data) will be done using Spearman’s rank order correlation coefficient test.

·  Comparison of the results of caries activity test (categorical data) and PROP sensitivity test (categorical data) will be done using Chi-square test.

7.3DOES THE STUDY REQUIRES ANY INVESTIGATION (OR) INTERVENTION TO BE CONDUCTED ON PATIENTS (OR) OTHER HUMANS (OR) ANIMALS? IF SO PLEASE DESCRIBE BRIEFLY:

Yes, the study requires investigations to be done on study subjects and they are as follows:

1.  Taste sensitivity investigation using PROP paper disk method.

2.  Investigation of saliva sample for caries activity using streptococcus mutans count test.

7.4 HAS ETHICAL CLEARANCE BEEN OBTAINED FROM YOUR INSTITUTION IN CASE OF 7.3?

Yes, ethical clearance has been obtained from the Institutional Review Board and attached.

REFERENCES

1.  Grewal H, Verma M, Kumar A. Prevalence of dental caries and treatment needs amongst the school children of three educational zones of urban Delhi, India. Indian J Dent Res2011;22(4):517-9.

2.  Öter B, Ulukapı I, Ulukapı H, Topçuoğlu N, Cıldır S. The relation between 6-n-propylthiouracil sensitivity and caries activity in schoolchildren. Caries Res2011;45(6):556-60.

3.  Drewnowski A, Henderson SA, Barratt-Fornell A. Genetic taste markers and food preferences. Drug Metab Dispos2001;29:535-8.

4.  Bartoshuk LM, Duffy VB, Lucchina LA, Prutkin J, Fast K. PROP (6-n-propylthiouracil) supertasters and the saltiness of NaCl. Ann N Y Acad Sci1998;855:793-6.

5.  Rupesh S, Nayak UA. Genetic sensitivity to the bitter taste of 6-n propylthiouracil: a new risk determinant for dental caries in children. J Indian Soc Pedod Prev Dent2006;24(2):63-8.

6.  Hegde AM, Sharma A. Genetic sensitivity to 6-n-propylthiouracil (PROP) as a screening tool for obesity and dental caries in children. J Clin Pediatr Dent2008;33(2):107-11.

7.  Furquim TR, Poli-Frederico RC, Maciel SM, Gonini-Júnior A, Walter LR. Sensitivity to bitter and sweet taste perception in schoolchildren and their relation to dental caries. Oral Health Prev Dent2010;8(3):253-9.

8.  Greene JC, Vermillion JR. The simplified oral hygiene index. J Am Dent Assoc1964;68:7-13.

9.  Klein H, Palmer CE, Knutson JW. Studies on dental caries. Public Health Rep1938;53:751-765.

10.  Hegde PP, Ashok Kumar BR, Ankola VA. Dental caries experience and salivary levels of Streptococcus mutans and Lactobacilli in 13-15 years old children of Belgaum city, Karnataka. J Indian Soc Pedod Prev Dent 2005;23(1):23-6.

PATIENT INFORMATION FORM

Principal Investigator: Dr. Krithi

Guide: Dr. Puja C Yavagal

Research Institute: Bapuji Dental College and Hospital, Davangere.

Information to the Participant

Your child is invited to take part in research study titled ‘Assessment of dental caries experience among 15 year old school students in Davangere city with different genetic sensitivity to bitter taste of 6-n-propylthiouracil - A cross sectional survey.’ This document provides you with all necessary information about the study. Please read this carefully. Make sure that you understand what your child’s participation would involve. In case you have questions, kindly ask them before you sign the consent form.

Introduction and purpose

Decay in the mouth is a major oral health problem in India. To tackle the problem of decay, prevention seems to be the best method. For planning preventive programs, risk of getting decay should be known. ‘Caries activity tests’ are tests which help dentists to find the risk of getting decay in future in his patient.Although caries activity tests are more detailed and give reliable results, majority of the tests are cumbersome, expensive and time consuming. Recently few studies state that a medicine by name Propylthiouracil can be used in a test called PROP test which may help us to know the risk of getting decay. This test is also easily applicable, quick, less expensive and safe. So this study aims at finding out the relationship between PROP test and risk of getting decay.

Procedure

If your child agrees to participate in the study, he/she will be asked not to eat anything for two hours before the start of the study. Your child’s identification details, history of dietary habits and methods of cleaning the mouth will be recorded. He/She will have to undergo a thorough examination of the mouth. Following that 1ml of your child’s saliva will be collected for investigations for decay producing organisms. Your child’s oral hygiene status and decay in the mouth will be recorded by a trained examiner. Then he/she will be tested for taste sensitivity to NaCl paper disc and PROP paper disc. They are supposed to taste these paper discs at separate time intervals and rate the taste intensity of both on a scale.

There is no compensation for participating in this study but your child’s effort in participation is highly valued and appreciated. You and your child are most welcome to ask any question at any time about the study. Your child’s participation will be entirely voluntary. He/She is free to refuse to take part or discontinue from the study at any time. Your child’s personal details obtained during the study will be maintained as confidential information. The results of the study may be published in a journal or presented as a scientific paper without revealing the identifying details about your child.

Name and address of the investigator:

Dr. Krithi

Postgraduate student,

Room no: 8

Department of Public Health Dentistry,

Bapuji dental college and hospital,

Davangere.

Mobile number: 9916820367

If you experience any grievances while participating in this study, feel free to call to this number

Dr. K. Sadashiva Shetty: 08192 - 220575