MINISTRY OF EDUCATION AND TRAINING NGUYEN MANH CUONG RESEARCH ON THE USE OF FLUORIDE VARNISH IN THE PREVENTION AND TREATMENT OF TOOTH DECAY Speciality Odonto Stomatology Code 62 72 06 01 PhD THESIS SU[.]
MINISTRY OF EDUCATION AND TRAINING NGUYEN MANH CUONG RESEARCH ON THE USE OF FLUORIDE VARNISH IN THE PREVENTION AND TREATMENT OF TOOTH DECAY Speciality: Odonto-Stomatology Code: 62.72.06.01 PhD THESIS SUMMARY Ha Noi – 2022 The project was done at: Science instructors: Assoc.Prof.PhD Le Thi Thu Ha Assoc.Prof.PhD Dao Thi Dung Counter-arguement: The thesis will be defended at the Thesis Judging Committee meeting at: At on , 2022 The thesis can be found at: Vietnam National Library 108 clinical Research Institute of medicine and forestry bibrary A THESISINTRODUCTION PROBLEM The World Health Organization, when summarizing global dental caries in 2003, concluded that tooth decay is still an oral health problem affecting 60-90% of students and the vast majority of mature people In particular, the increased incidence in developing countries is the result of inadequate exposure to fluoride With more than 50 years of clinical and experimental research, fluoride serves as the gold standard agent in the prevention and treatment of caries, reducing the prevalence and severity of caries globally Research by Marinho VC and partners, through a meta-analysis of intervention studies with fluoride varnish, showed that fluoride varnish reduced tooth decay by 33% In Vietnam up to now, although there are many research on tooth decay at all ages, most of these studies only stop at diagnosing caries at late stages, so the effectiveness of disease prevention and treatment is still low There are many but incomplete studies on the caries status of children in the use of fluoride varnish for prevention and treatment of tooth decay Stemming from the above problems, we carried out the project "Research on the use of fluoride varnish in the prevention and treatment of tooth decay" with the following objectives: Determine the current status of permanent decay of tooth number of 7-8 year old students in Hanoi city in 2017 Evaluate the effectiveness of using Enamelast 5% NaF fluoride varnish on a group of students with early-stage caries Describe the mineralization process of Enamelast 5% NaF fluoride varnish on experimental tooth enamel THE URGENCY OF THE SUBJECT Cavities being not detected at an early stage makes it impossible for doctors to choose any other treatment method other than restoration, instead of using non-invasive measures Over the past 20 years, the omission of early caries lesions has shaped the conservative clinical management of caries Finding out the causes and pathogenesis of dental caries has led to a change in the prevention and treatment of caries Modern dentistry with advanced methods helps to detect early clinical caries to help prevent the progression of caries Today's perspective does not stop at the level of drilling and filling cavities that have formed cavities, but also includes prevention and treatment of early caries (not yet created cavities) in order to reduce costs and increase efficiency of the treatment PRACTICAL MEANINGS AND NEW CONTRIBUTION 1) Experimental study has demonstrated the mineralizing effect of 5% Enamelast fluoride varnish on permanent tooth enamel 2) Detecting the high rate of 6th permanent tooth decay among 7–8-year-old students in Hanoi city, especially the early 6th stage permanent tooth decay rate (D1, D2) 3) The effectiveness of 5% Enamelast fluoride varnish in the prevention and treatment of restoring early stage permanent caries (D1, D2) is very high 4) Early stage permanent caries lesions (D1, D2) mostly progress to more severe lesions over time, in the condition of brushing only with regular Colgate children's toothpaste 5) The technique of applying fluorine varnish to prevent and treat tooth decay is simple, safe, and can be done right at primary schools STRUCTURE OF THE THESIS In addition to the problem statement and conclusion, the thesis consists of chapters: Chapter I: Overview of the research problem, 39 pages; Chapter II: Research Objects and Methods, 27 pages; Chapter III: Research results, 40 pages; Chapter V: Discussion, 31 pages The thesis has 43 tables, 03 charts, 48 images, 127 references (55 Vietnamese, 72 English) B CONTENT OF THE THESIS Chapter OVERVIEW 1.1 Anatomy and histology of enamel: Enamel is of ectodermal origin; enamel is the hardest tissue in the body - Physically: enamel is hard, brittle, clear and resistant to X-rays, with a density of 2.3 - compared to dentin - Organizational structure: The enamel cylinder runs throughout the enamel thickness, sometimes there is a bend and change in the direction of the enamel axis 1.2 Dental caries 1.2.1 Definition of early dental caries and caries 1.2.1.1 Dental caries: is a bacterial infection of calcified tissues, characterized by demineralization of inorganic components and destruction of organic components of hard tissues 1.2.1.2 Early dental caries: The phenomenon of lowering pH leading to demineralization, clinical damage losing 10% of minerals is called early caries 1.2.2 Dental caries: Dental caries is considered a disease caused by many causes 1.2.3 Pathophysiology of caries process: The kinetics of caries process is an imbalance between the two processes of demineralization and remineralization 1.2.4 Epidemiology of dental caries and early dental caries - Global caries epidemiology: WHO concluded dental caries remains a common disease among most infectious diseases - Vietnam: The prevalence of the disease is at a high level and tends to increase, especially in rural and mountainous areas 1.2.5 Treatment and prevention of tooth decay 1.2.5.1 Treatment of caries: early caries lesions with remineralization measures can restore the structure 1.2.5.2 Prevention of tooth decay: it has been proven that using fluoride to prevent tooth decay has reduced tooth decay by 50% 60% 1.3 Methods of early diagnosis of tooth decay There are many methods for diagnosing early caries, each with a different threshold and diagnostic criteria in which fluorescence laser has high sensitivity and specificity, efficiency, and simple technique The combination of ICDAS and Diagnodent has shown to be more effective in the diagnosis and treatment of early tooth decay 1.4 The role of fluoride varnish in the prevention and treatment of tooth decay: Fluoride varnish was born as an effective tool to protect teeth, to help reduce the risk of tooth decay, at the same time, to remineralize and restore damaged tooth enamel to the orgininal condition at an early stage Currently, in Vietnam, there is no experimental study on the effect of Enamelast NaF 5% fluoride varnish on tooth enamel 1.5 Experimental study on early dental caries Chapter RESEARCH SUBJECTS AND METHODS Our study consisted of three distinct designed studies: - Cross-sectional descriptive study: To describe the status of permanent tooth decay number of 7–8-year-old students in Hanoi city - Interventional study: To evaluate the effectiveness of prevention and treatment of 5% Enamilast fluoride varnish on the group of students with early permanent tooth decay - Experimental study: to determine the evidence of fluoridation of 5% Enamilast fluoride varnish into tooth enamel 2.1 Cross-sectional descriptive study 2.1.1 Subjects of the study: Students aged 7-8 years old, born in 2010 and enrolled in grade for the 2016-2017 school year 2.1.2 Time: from 4/2017 to 6/2017 2.1.3 Research Methods * Study design: is a descriptive cross-sectional study, to determine the rate of permanent tooth decay number of - 8-year-old students * Research sample The sample size was calculated according to the formula [18]: n Z (21 / ) pq DE d2 Note: n: sample size; z(1- α/2) : confidence coefficient at 95% probability level; p: estimated rate of permanent tooth decay of 7year-old students (p = 25.4%) [3]; q: estimated rate of no permanent tooth decay of 7-year-old students (q = 74.6%); d: desired accuracy 3.5%; DE: design factor = * Sample size: Calculated as 1190 students * Sampling: Based on geographical characteristics, socio-economic situation, population, we divide Hanoi into floors and clusters The total number of students participating in the study of clusters is 1212, larger than the research sample which is 1190 2.1.4 Conduct research - Training and standardizing researchers on examination methods Initial screening of 100 patients * Clinical examination procedure 2.2 Interventional Research 2.2.1 Research time and place: From 4/2017 to 12/2019 - Location: Thuy Linh Primary School, Hoang Mai City, and Van Hoa Primary School, Ba Vi Rural, Hanoi City 2.2.2 Subjects: Students aged 7-8 years old were examined from a cross-sectional descriptive study that randomly selected students with early-stage permanent caries of the first molars 2.2.3 Research Methods * Study design: A randomized clinical intervention study with a control group, to evaluate the effectiveness of fluoride varnish in the prevention and treatment of permanent tooth decay, after months, 12 months and 24 months * Research sample We followed the formula for calculating sample size for the intervention study of Lwanga Z(1-ỏ/2) : confidence coefficient at 95% probability level (=1.96); Z1-ò : sample force (=90%); P1: the rate of permanent tooth decay in the intervention group, after 24 months of follow-up was estimated at 25%; P2: rate of permanent tooth decay in the control group, estimated at 45% after 24 months of follow-up; P : (P1+P2)/2; n1 : sample size of the intervention group (number of students with fluoride varnish); n2: sample size of the control group (number of students who received Colgate children's cream); Minimum clinically significant difference: δ = 10% (0.10), that is, the desired difference between the experimental and control groups ≥ 10% with 5% probability, thus β = -1.645 According to the formula to calculate the minimum required sample size for study groups is n= n2= n1= 108 students * Sampling: Randomly select schools, 01 school in rural area and 01 school in urban area Randomly divide the schools into an intervention group and a control group 2.2.4 Conduct research Training and benchmarking for researchers on examination and intervention methods The process of performing clinical examination and intervention - Step 1: Guide to cleaning teeth with brush, toothpaste and water before entering the examination table - Step 2: Examining to detect caries by normal observation method according to the standards of the ICDAS international caries assessment and detection system at time T0, T1, T2, T3 - Step 3: At T0, the permanent caries with lesions D1, D2 are continuously monitored in the times after T1, T2, T3 to monitor the progression of lesions - Step 4: Carry out the intervention with fluoride varnish for the intervention group at the following time points starting (T0) months (T1), 12 months, 18 months (T2), and 24 months (T3) 2.3 Research content of descriptive cross-sectional and interventional studies 2.3.4 Monitor, manage patients and collect research data 2.3.5 Reliability: Kappa index = 0.8 reached a level of close agreement in dental examination 2.3.6 Limiting errors in research 2.4 Experimental study 2.4.1 Experimental research object: teeth - extracted for orthodontics collected from clinics in Hanoi 2.4.2 Research time and place: from 1/2018 - 7/2018 at Faculty of Morphology, Institute 69 - Mausoleum Command 2.4.3 Research Methods: It is an invitro study – an experimental, interventional, controlled study in the laboratory 2.4.4 Research process 2.5 Data processing: Our study used techniques and software SPSS 20.0, R software and some statistical algorithms 2.6 Ethics in research: The study was conducted in accordance with the research protocol approved by the protocol committee of the 108 Clinical Institute of Medicine and Pharmacy Chapter RESEARCH RESULT 3.1 Current status of dental caries, about the prevalence of permanent first molar caries (tooth number 6) 3.1.1 General information of research subjects - On the study of 1212 students at 06 primary schools, including schools in the City with the number of 608 students accounting for 50.2% and schools in the Rural with the number of 604 students accounting for 49.8% - The distribution of students between schools, and between City schools and Rural schools is similar Male students accounted for 54.3%, higher than female students which accounted for 45.7% 3.1.2 Dental caries status of study subjects 100% 80% 60% Decay 40% Not Decay 20% 0% WHO ICDAS Chart 3.3 Compare the rate of tooth decay according to ICDAS and WHO The rate of permanent tooth decay according to ICDAS standards is 66.6%, much larger than the WHO standard of only 7.7% 3.1.2.1 Distribution of the rate of permanent decay of tooth number by sex The percentage of students with permanent tooth decay including early tooth decay (D1, D2) and late stage (D3) among male students was 67.6%, higher than that of female students at 65.3% D3 level caries lesions are common in the occlusal surface with the overall rate accounting for 5.1%, and the distal face is the lowest 3.1.2.2 Distribution of the rate of permanent tooth decay number by geographical location a) By City (urban) and Rural (rural): Table 3.9 Distribution of the rate of permanent tooth decay of tooth from level D3 according to the study subjects' geography (n=1212) Yes No Total p Geography City SL % 44 7,2 564 92,8 608 50,2 Rural 49 8,1 555 91,9 604 49,8 Total 93 7,7 1119 92,3 1212 100,0 SL % SL % 0,591 The rate of permanent tooth decay number is determined according to ICDAS standards The specific statistics of the number of students in the City is 378, accounting for 62.2%, while in the Rural it is 429 students, accounting for 71.0% This difference is statistically significant with p=0.001 The rate of tooth decay was lowest in Kim Lien Primary School, Dong Da City with 59.0%, and highest in Van Hoa Primary School, Ba Vi Rural with 73.2% 3.1.2.3 Percentage of permanent tooth decay according to ICDAS For the upper six teeth on the right, the D3 lesions account for 0.9%, only appearing on the chewing surface The proximal, buccal, distal, and lingual surfaces only appear at levels of damage D1, D2 The chewing surface still accounts for the highest percentage of the carious lesions at levels D1, D2 The distal surface has the lowest rate of carious lesions e 13 decreased from 62.7% to 53.7% after 24 months Both groups had an increase in caries from D2 level to D3 level, but the intervention group increased little Table 3.38 Prevalence of early tooth decay (D1, D2) in the fluoride varnish intervention group and the control group at the time points before the intervention, after months, 12 months and 24 months % of progress Damage Group Before 06 12 24 CT months months months 897 826 684 Invention 1019 (39,8) (35,0) (32,2) (26,7) 941 1015 1114 1102 Control (37,1) (39,0) (42,9) (42,4) 1509 1619 1673 1793 Without Invention (58,9) (63,2) (65,4) (70,0) decay 1629 1541 1420 1396 D0 Control (62,7) (59,3) (54,6) (53,7) The rate of D1 and D2 caries in the varnish group gradually decreased over time In the control group, it increased over time Table 3.39 Efficiency index and intervention effectiveness of fluoride varnish on the rate of no caries over the study periods Withou decay HQCT Time Invention Control p (%) Qty % Qty % Beginning 1509 58,95 1629 62.65 After months 1619 63,24 1541 59.27 0,013 12,62 CSHQ (%) 7,28 -5,4 Beginning 1509 58,95 1629 62.65 < After 12 months 1673 65,35 1420 54.62 23,68 0,001 CSHQ (%) 10,86 -12,82 Beginning 1509 58,95 1629 62.65 < After 24 months 1793 70,04 1396 53.69 33,11 0,001 CSHQ (%) 18,81 -14,3 With decay D1, D2 The effectiveness index in the varnish group over time increased 14 from 7.28% after months to 10.86% after 12 months and increased to 18.81% after 24 months The effectiveness of intervention after 24 months is 33.11% 3.3 Result of demineralization and remineralization of fluorine 3.3.1 Diagnodent value on research sample Table 3.40 Diagnodent index of the group of teeth studied before and after demineralization Time n Value of Diagodent Before demineralization 60 9,6 ± 2,3 After demineralization 60 18,2 ± 1,3 Before demineralization, all teeth of the study group had DD index within the normal range of 9.6 ± 2.3 (