1 Recent Research Experience Recent Research Experience in Preventive Dentistry and Oral in Preventive Dentistry and Oral Epidemiology Epidemiology Gao Xiaoli 11 Feb 2008 Outline: Outline: Ph.D. Research (2004-2007) Other Research Involvements (2000-2007) Msc research Educational research Co-supervising Undergraduate Research Opportunities Programme (UROP) projects 1
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Recent Research Experience Recent Research Experience in Preventive Dentistry and Oral Epidemiologyin Preventive Dentistry and Oral Epidemiology
Gao Xiaoli11 Feb 2008
Outline:Outline:
Ph.D. Research (2004-2007)
Other Research Involvements (2000-2007) Msc research Educational research Co-supervising Undergraduate Research Opportunities Programme (UROP) projects
1
2
Caries Status among Preschoolers in Singapore Caries Status among Preschoolers in Singapore and Development/Validation of and Development/Validation of
% with rampant caries (defined as caries affecting the smooth surfaces
of two or more maxillary incisors): 16.5%
Severe Early Childhood Caries (S-ECC) (AAPD criteria): 28%
d- component: 90%
a Rampant caries defined as caries affecting the smooth surfaces of two or more maxillary incisors (Al-Malik et al., 2002).
b Main statistics adjusted by “race”.
RREESSUULLTTSS
28a Rampant caries was defined as caries affecting the smooth surfaces of two or more maxillary incisors (Al-Malik et al., 2002). b HDB stands for Housing & Development Board, which is the main authority managing the development of public housing in Singapore.
* There were significant differences (p<0.05) in the proportions/means between groups with different number of *s.
Disparity of Oral Health RREESSUULLTTSS
29
Significant Caries Index (SiC), i. e. the mean (SD) deft for one third of the population with the highest deft values (Bratthall, 2000):
4.49 (3.23)
Polarized Distribution of Caries
% of children % of lesions
deft>2 23% 88%
deft≥4 16% 78%
RREESSUULLTTSS
30
44% of children developed new caries, including 13.3% of children who were caries-free at baseline.
Caregivers and Infant Feeding PracticeCaregivers and Infant Feeding PracticeCaregivers and infant feeding practice %
N=1754
Primary caregivers Parents 47
Grandparents 22
Maid
Grandparents and maid
17
11
Others 4
Breastfeeding ≤12 months 89
>12 months 11
Bedtime feeding with breast, bottle of
milk/ formula/juice, sweets at age of 1
Frequently/almost every night 37
Never/occasionally 63
Used milk bottle before sleep at age of 1 Frequently/almost every night 64
Never/occasionally 36
RREESSUULLTTSS
34
Diet HabitsDiet Habits
Diet habits
%
N=1754
Meals/snacks per day 3-5 times
≥6 times
87
13
Between-meal sweet snacks <2 times a day 55
≥2 times a day 45
Bedtime sweets without brushing teeth Frequently/almost every night 12
Never/occasionally 88
Do you agree “I have the ability to
withhold frequent sugar snacks from
my child between meals even when
he/she is crying for it”?
Agree
Neutral
Disagree
29
60
11
RREESSUULLTTSS
35
Oral Hygiene Practice Oral Hygiene Practice
%
Oral hygiene practice
N=1754
Frequency of toothbrushing <2 times a day 31
≥2 times a day 69
Time of brushing per time ≤2 minutes 70
>2 minutes 30
Adults’ guidance in toothbrushing Yes 45
No 55
Do you agree with the statement “I can do
a good job brushing my child’s teeth each
day thoroughly even when I am very busy”?
Agree Neutral Disagree
21
66
13
RREESSUULLTTSS
36
Oral Hygiene StatusOral Hygiene Status
Very goodPI<0.4
GoodPI 0.4-1.0
ModeratePI >1.0, ≤2.0
BadPI>2.0
% of Subjects(N=1782)
22.1 52.1 25.4 0.4
Demographic/socioeconomic subgroups with better oral hygiene:
Indians (p<0.001)
Girls (p=0.047)
Children of more educated fathers (p=0.025)
Oral hygiene behaviors linked to better oral hygiene:
Toothbrushing by adults or with adults’ guidance (p=0.014)Brushing more frequently (p=0.001) and longer per time (p=0.012)Parents’ confidence in brushing child’s teeth (p=0.002)Parents’ awareness of fluoride toothpastes (p=0.026)
RREESSUULLTTSS
37
Fluoride ApplicationsFluoride Applications
%
Fluoride applications
N=1754
Use of fluoride toothpaste Yes
No
Not sure
68
12
19
Ever lived in non-fluoridated communities Yes
No
Not sure
3
71
26
Use of other fluorides Yes
No
Not sure
5
78
17
RREESSUULLTTSS
38
Utilization of Dental ServicesUtilization of Dental ServicesUtilization of dental services %
N=1586
Age regarded as appropriate to
start dental check-ups
1-3 years
4-6 years
≥7 years
14
47
39
Annual dental visits for parents Yes 45
No 55
Annual dental visits for children Yes
No
8
92
Reason for not visiting dentists
No money
No time
Transportation difficulty
Dental fear
Teeth did not bother the child
Too young
Other reasons
12
9
1
15
58
8
1
RREESSUULLTTSS
39
Parental Knowledge/Attitude on Oral HealthParental Knowledge/Attitude on Oral Health %
Parental knowledge/attitude on oral health
N=1586
Did you ever receive advices about the
relationship between diet and tooth decay
from a dentist or medical doctor?
Yes
No
29
71
Have you ever been told about early
childhood caries (tooth decay)?
Yes
No
25
75
Do you think baby teeth are important?
Do you believe that putting baby to bed with
a milk bottle is bad for his/her teeth?
What do you think is the main reason for
tooth decay?
Yes
No
Yes
No
Tooth worms
Heatiness
Insufficient toothbrushing
Sugar
Bacteria
89
11
69
31
4
1
23
73
70
RREESSUULLTTSS
40
Systemic Diseases and Regular MedicationSystemic Diseases and Regular Medication
%
N=1586
Systemic diseases Yes
No
14
86
Regular medication Yes
No
5
95
Parents’ Perception of the Children’s Caries StatusParents’ Perception of the Children’s Caries Status
Sensitivity: 49%
Specificity: 87%
Accuracy: 72%
RREESSUULLTTSS
41
Discrepancy between knowledge/attitude and practice
Socio-economic characteristics
e.g. poor infant feeding practice
frequent sweets
poor oral health knowledge
barriers to dental services
Oral Health Knowledge Attitude and PracticeOral Health Knowledge Attitude and Practice
for low socio-economic group
RREESSUULLTTSS
42
Results
1. Intra-examiner reliability and profile of study sample
Prob (Y=1) = exp (a + β1X1 + β2X2+…)/ [1+exp (a + β1X1 + β2X2+…)]
For identifying the “any-risk” (∆deft>0) individual.
Requires
Questionnaire
Oral hygiene evaluation
Microbiological & plaque
pH tests
RREESSUULLTTSS
60
Comparison with Cariogram
% Area under
ROC curveSensitivity
(SN)
Specificity
(SP)
SN+SP Accuracy
Full-scale model 90 90 180 90 0.961
Clinical screening model 86 73 159 79 0.833
Cariogram 71 66 136 68 0.731
RREESSUULLTTSS
61
Caries has been successfully controlled among schoolchildren in Singapore.
However, the caries rate for preschoolers in Singapore is obviously higher than for most developed countries.
1Source of data: Lo and Bagramian, 1997 & this study 2Source of data: US/DHHS, 2007
Singapore1 USA2 P
Schoolchildren
Year of survey 1994 2002
6-11 years
% affected 41.8 49.0 <0.001
dft 1.08 1.67 <0.001
6-18 years
% affected 41.3 42.0 0.308
DFT 1.05 1.60 <0.001
Preschoolers
Year of survey 2005 2002
% affected 40.0 27.9 <0.001
dft 1.50 1.06 <0.001
Relatively Poor Oral Health among PreschoolersRelatively Poor Oral Health among PreschoolersD D I I SSCCUUS S S S IIOONN
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Infant
Promoting proper feeding practice
Reducing colonization of cariogenic bacteria
Regular oral health education in kindergartens
Involve all caregivers
Meet the specific need of population subgroups
Extension of School Dental Service to preschoolersExtension of School Dental Service to preschoolers
Oral Health Education/Promotion Oral Health Education/Promotion D D I I SSCCUUS S S S IIOONN
63
Important of “Targeting”
The disparity of oral health is obvious in this population.
Some population subgroups, such as Malays and low socio-economic groups, should be targeted for caries prevention.
At individual level, those at-risk children need to be identified for early and intensified caries prevention and intervention.
D D I I SSCCUUS S S S IIOONN
64
Multiple risk factors/indicators identified in this study serve as important references for targeting high-risk groups and individuals.
Difference types of CRA Models were constructed and validated in this study. The combination of these models could provide options for different purposes at the community and clinical settings.
CRA ModelsCRA ModelsD D I I SSCCUUS S S S IIOONN
65
Methods
C4.5
Support Vector Machine (SVM)
NBay
Multi-Layer Perceptron (MLP)
ANN improved the accuracy of prediction
when limited information was available
for predicting “number of new affected surfaces” (p<0.05)
A computerized, user-friendly CRA program will be developed.
Data Mining with Artificial Intelligence Neural Network (ANN)
D D I I SSCCUUS S S S IIOONN
66
Early childhood caries is a health problem that warrants the attention of the profession and the resources of the society.
Sustainable oral health promotion programs should be established.
The CRA models established in this study could be practically useful tools for cost-effective caries control and individualized treatment planning.
ConclusionsConclusionsCCOONNCCLLU U S S IIOONNSS
67
ReferencesReferences Al-Malik MI, Holt RD, Bedi R (2002). Erosion, caries and rampant caries in preschool children in Jeddah, Saudi Arabia. Community Dental and Oral
Epidemiology 30:16-23. Armfield J, Spencer AJ (2003). Increase in caries experience in Australian Children. Abstract # 0151. The 81st General Session of the International
Association for Dental Research. June 25-28, 2003. Goteborg, Sweden. Bratthall D (2000). Introducing the Significant Caries Index together with a proposal for a new global oral health goal for 12-year-olds. Int Dent J
50(6):378-84. Brown JP. A new curriculum framework for clinical prevention and population health, with a review of clinical caries prevention teaching in U.S. and
Canadian dental schools. J Dent Educ. 2007 May;71(5):572-8. Ettinger RL (1999). Epidemiology of dental caries. A broad review. Dent Clin North Am 43(4):679-94. Featherstone JDB, Adair SM, Anderson MH, Berkowitz RJ, Bird WF, Crall JJ, et al (2003). Caries management by risk assessment: consensus
statement. J Calif Dent Assoc 31:257-69. Frencken JE, Kalsbeek H, Verrips GH (1990). Has the decline in dental caries been halted? Changes in caries prevalence amongst 6- and 12-year-old
children in Friesland, 1973-1988. Int Dent J 40:225-30. Haugejorden O, Birkeland JM (2002). Evidence for reversal of the caries decline among Norwegian children. Int J Paediatr Dent. 12(5):306-15. Holloway PJ (1991). International dental public health. Curr Opin Dent. 1(3):348-56. Hong HL (2003). Caries prevalence and associated risk factors in 2-4 year old children in Singapore. Thesis submitted for the degree of Master of
Science in Pediatric Denistry at the Horace H. Rackham School of Graduate Studies, the University of Michigan, U.S.A. (Thesis committee members: L Straffon, R Bagramian, C.Y. Hsu, H. Nainar).
Hsu CS, Lee WO, Teo CS (2001). Caries risk assessment of Singapore kindergarten children: A pilot study. Journal of Dental Research, 80 (2001): 566. (Special Issue on Dentistry). (Paper presented at 79th General Session & Exhibition of the International Association for Dental Research, 27-30 June 2001, Makuhari Messe & Prince Hotel, Chiba, Japan). (Abstract 316).
Lo GL, Bagramian RA (1997). Declining prevalence of dental caries in school children in Singapore. Oral Dis 3:121-5. Loh T (1996). Thirty-eight years of water fluoridation--the Singapore scenario. Community Dent Health 13:47-50. National Institute of Health (NIH) consensus panel (2001). National Institute of Health consensus development conference statement. Presented at the
Consensus Development Conference on Diagnosis and Management of Dental Caries Throughout Life, March 26-28, 2001. Natcher Conference Center, National Institutes of Health, Bethesda, MD. USA.
Nishi M, Stjernsward J, Carlsson P, Bratthall D (2002). Caries experience of some countries and areas expressed by the Significant Caries Index. Community Dent Oral Epidemiol 30(4):296-301.
Olsen CB, Brown DF, Wright FA (1986). Dental health promotion in a group of children at high risk to dental disease. Community Dent Oral Epidemiol 14(6):302-5.
Ong G, Yeo JF, Bhole S (1996). A survey of reasons for extraction of permanent teeth in Singapore. Community Dent Oral Epidemiol 24(2):124-7. Pine CM, Adair PM, Nicoll AD, Burnside G, Petersen PE, Beighton D, et al (2004a). International comparisons of health inequalities in childhood
dental caries. Community Dent Health 21(1 Suppl):121-30. Pitts NB, Boyles J, Nugent ZJ, Thomas N, Pine CM (2003). The dental caries experience of 5-year-old children in England and Wales. Surveys co-
ordinated by the British Association for the Study of Community Dentistry in 2001/2002. Community Dent Health 20(1):45-54. Seppa L (2001). The future of preventive programs in countries with different systems for dental care. Caries Res 35 (Suppl 1):26-9. Singapore Department of Statistics (2005): General household survey 2005. http://www.singstat.gov.sg/. Speechley M, Johnston DW (1996). Some evidence from Ontario, Canada, of a reversal in the dental caries decline. Caries Res 30(6):423-7. Truin GJ, van't Hof MA, Kalsbeek H, Frencken JE, Konig KG (1993). Secular trends of caries prevalence in 6- and 12-year-old Dutch children.
Community Dent Oral Epidemiol 21(5):249-52. U.S. Centers for Disease Control and Prevention (2005). Surveillance for dental caries, dental sealants, tooth retention, edentulism, and enamel fluorosis
- United States, 1988–1994 and 1999–2002. In: Surveillance Summaries, MMWR 54(No. SS-3). U.S. Department of Health and Human Services (US/DHHS) (2000). Oral health in America: a report of the Surgeon General. J Calif Dent Assoc,
28(9):685-95. U.S. Department of Health and Human Services (US/DHHS) (2007). Trend in oral health status: United States, 1988-1994 and 1999-2004. Centers for
Disease Control and Prevention, National Center for Health Statistics. Health, United States. World Health Organization (WHO) (1997). Oral health surveys: Basic methods. 4th edition. WHO Geneva. World Health Organization (WHO) (2001). Changing levels of dental caries experience (DMFT) among 12-year-olds in developed and developing
countries. http://www.whocollab.od.mah.se/index.html World Health Organization (WHO) (2003). The World Oral Health Report 2003. WHO, Geneva.
Co-supervising Undergraduate Research Opportunities Programme (UROP) Projects
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Msc Research
Synergistic Effect of Combined Laser-Fluoride Treatment on Root Demineralization
A low-energy CO2 laser treatment (energy density 1.14 J/cm2) has been established with effect on inhibiting root demineralization.
A synergistic effect of combined laser-fluoride treatment was demonstrated.
OOTTHHEER R
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Groups N Mean (SD) of
Lesion Depth (µm)
Ranking * % Reduction
Control 15 160 (14) I
Laser alone 15 113 (8) II 30
Fluoride alone 15 111 (6) II 31
Fluoride + Laser 15 25 (7) III 85* The ranking order was obtained from the post hoc Tukey-Kramer multiple-comparison tests. Groups with different numerals are statistically different (p < 0.05).
Journal of Dental Research 85(10): 919-923
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Msc Research
Synergistic Effect of Combined Laser-Fluoride Treatment on Root Demineralization
The possible mechanism may be the laser-induced fluoride uptake, in firmly and loosely bound forms.
OOTTHHEER R
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Groups Mean (SD) of
Fluoride Uptake #
Ranking *
Firmly bound fluoride Non-laser 73 (24) I
Laser 368 (26) II
Loosely bound fluoride Non-laser 567 (33) III
Laser 777 (78) IV# The elemental analysis was carried out through Time of Flight - Secondary Ion Spectrometry (ToF-SIMS). There is no unit for fluoride concentration because the intensity of ionized 19F was normalized against the intensity of ionized 31P, the reference element for negative ions in the tooth.* The ranking order was obtained through a general linear model for repeated measurements. Groups with different numerals are statistically different (p < 0.05).
Journal of Dental Research 85(10): 919-923
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Educational Research
Dentists’ knowledge attitudes and practice of preventive dentistry and oral health education in Singapore. Hsu CY, Loh T, Gao XL, Ong G. Submitted to Community Dental Health.
Dental students’ knowledge-attitude-practice of preventive dentistry. Hsu CS, Gao XL, Loh T, Ong G. Oral presentation at 16th South East Asia Association for Dental Education Annual Meeting, Sept 2005, Malacca, Malaysia. Abstract #SO-3.
Teaching reform and graduates’ knowledge attitude practice of preventive dentistry. Hsu CY, Loh T, Gao XL, Ong G. Oral presentation at 19th South East Asia Association for Dental Education Annual Meeting, Sept 2007, Bali, Indonesia. Abstract #SO-5.
Effects of multimodal and multi-dimensional learning in “Community Health Study” module. Hsu CY, Loh T, Gao XL. Poster presentation at 5th Asia Pacific Medical Education Conference, Jan 2008, University Cultural Center, National University of Singapore.
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Educational Research
The teaching reform included
Review and reconstruction of curriculum
Adjustment of teaching philosophies and priorities Emphasizing interactive, collaborative, self-directed,
and reflective learning.
Employment of innovative teaching strategies Seminars, project-based modules, case studies, role-
plays, field trips, and student-centred community studies
Refinement of course requirement and assessment system Class activities, quizzes, taking home exams, group
projects, oral exams, and self/peer evaluation
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Educational Research
The anonymous surveys among students showed
There were significant improvements in their satisfaction on the curriculum, interest in related subjects, attitude of learning, knowledge acquirement, and application of knowledge in their clinical practice and research projects.
This self-directed, truth-finding process has impacted their lives and re-directed their thinking.
Students were equipped with basic tools for their life-long learning and evidence-based dentistry.
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Undergraduate Research Opportunities Programme (UROP) Project (1)
Preliminary Caries Risk Study in Chinese ChildrenPreliminary Caries Risk Study in Chinese Children
Oral health survey in a preschool education centre in Dali Bai Autonomous Region, Yunnan Province, P. R. China
N=235
Age range: 4-6 years
Caries is a severe oral health problem % affected: 87% Mean (SD) deft and defs: 5.6 (3.8) and 10.4 (7.7) d- component: 98.8%
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Undergraduate Research Opportunities Programme (UROP) Project (1)
Preliminary Caries Risk Study in Chinese ChildrenPreliminary Caries Risk Study in Chinese Children
A few A few caries risk factorscaries risk factors have been identified sweet intakes (p=0.019) poor oral hygiene (p=0.004) not using fluoride toothpaste (p<0.001)
Cariogram did not predict the caries increment accurately in this population.
OOTTHHEER R
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Acid-neutralizing Capability of Foods after Coca Cola Consumption
“Peanut and cheese” was an effective food therapy in neutralizing plaque pH drop induced by Coca Cola.
Consumption of “cheese alone” or “cheese and mushroom” possibly provides some protective effects.
The finding of this study is useful for providing diet advices for caries prevention dispensed to regular consumers of Coca Cola.
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Undergraduate Research Opportunities Programme (UROP) Project (2)
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Cariostatic Effect of Probiotic Drink YakultCariostatic Effect of Probiotic Drink Yakult®
A 2-week consumption of Yakult® reduced the acid production in plaque of moderate-risk young adults.
The mechanism may be the Yakult® effect on inhibiting cariogenic bacteria.
The probiotic drink Yakult® is promising in preventing caries.
Undergraduate Research Opportunities Programme (UROP) Project (3)
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Awards for UROP Projects
2nd Place Award (2007)
Undergraduate Research Opportunities Programme Competition
National University of Singapore
Complimentary Award (2006)
Preventive Programme Competition
South East Asia Association for Dental Education (SEAADE)