nghiên cứu hiệu quả điều trị tẩy trắng răng sống nhiễm sắc tetracycline bản tóm tắt tiếng anh

1 THESIS INTRODUCTION ACKNOWLEDGEMENT Discoloration of teeth occupied a high percentage (86.90%) in the community, including tetracycline stained teeth was 22.86% and this percentage was mainly found in middle age. Sign of tetracycline stained teeth is serious changes of teeth color in which, normal teeth change into yellow-brown or green or dark grey colors, this obviously influences to aesthetics and causes less confidence in the life. To treat to a tetracycline stained denture, there are many methods such as composite fillings, porcelain veneers, full-coverage crowns. These treatments require the patients suffering intervened dental operations which cause loss of hard tissue of teeth, time-consuming, costly and this acquires to be replaced periodically. A protocol of less invasive for hard tissue but changing color of teeth is by whitening discolored teeth with the help of cold light activation. Currently in Viet Nam, further study projects, comprehensive clinical, safe bleaching protocol on the morphological structure of the enamel surface and evaluation the effectiveness of the in-office bleaching treatment tetracycline stained teeth with the help of light activation; especially cold light source is still very limited. Therefore, we conducted a thesis: “Research effectiveness of vital bleaching treatment for tetracycline stained teeth” with the aims: 1. Describle clinical characteristics of tetracycline stained teeth at degree I and degree II on patients who were treated by vital bleaching method. 2. Assess effectiveness of vital bleaching method for tetracycline stained teeth. 3. Evaluate structural changes of enamel surface morphology under the scanning electron microscopy on tetracycline stained teeth after experimental bleaching. THE NECESSARIES OF THE THESIS Denture of a person serves not only for chewing function, but also plays an important role in his/her pronunciation, communication in social community with charming smiles, and it makes people become more confident. A white and beautiful denture is the desire of everyone, 1 1 2 especially people who are being suffered by tetracycline stained teeth. How is clinical characteristics of degree I and degree II tetracycline stained teeth? How efficacy do tetracycline stained teeth bleach? How do enamel surface morphology change under the scanning electron microscopy on tetracycline stained teeth after experimental bleaching? Those need to be examined, identified, in order to contribute to a safe and effective bleaching protocol for tetracycline stained teeth relying on surface of enamel structure. PRACTICAL SIGNIFICANCE & NEW CONTRIBUTION 1. Description of the clinical characteristics of degree I and degree II tetracycline stained teeth. Identified indicators of the Munsell color spectrum and CIE La*b* color space for each degree of tetracycline stain. 2. Affirm vital bleaching treatment for tetracycline stained teeth achieve high effectiveness and safe on structure of enamel surface morphology. 3. There are specific evidences of the bleaching agents based on trials performed in different environments on enamel surface morphology. 4. Establish a safe and effective bleaching protocol for surface of enamel structure of tetracycline stained teeth. 5. Apply a colorimetric technique by Vita Easyshade compact spectroradiometers in diagnosis and treatment of a stained denture. 6. Affirm effectiveness of the warning of teeth staining by tetracycline in the community. THESIS STRUCTURE Thesis consists 146 pages, apart from the acknowledgement, conclusion, and proposal consist 5 pages, the thesis consists of 4 chapters: Chapter 1: General study issue (including 34 pages), Chapter 2: Research objectives and methodologies (including 30 pages), Chapter 3: Research results, (including 37 pages), Chapter 4: Discussion, (including 40 pages). The thesis comprises 40 tables, 28 charts, 40 photos, 156 references (16 of which were in Vietnamese, and other 140 were in English). B. THESIS CONTENTS Chapter 1. OVERVIEW 1.1. Histological structure of tooth enamel definition. 1.1.1. Histological structure of tooth enamel 2 2 3 Organic forms: Mature enamel consists mainly soluble and insoluble proteins and a small amount of fat and carbohydrates. Teeth staining are pigments combined with fatty acids, proteins, enzymes, on the enamel surface, it contains long chain links, alternating single link chains and double link chains. Bleaching has used hydrogen peroxide (H 2 O 2 ) to remove proteins. Observation under scanning electron microscopy (SEM), H 2 O 2 decomposes into free radicals causing oxidation of fatty acids and proteins, cleavaging long - chain links into the small branches, and the proteins on the enamel surface are removed. 1.1.2. Metabolic process of tooth enamel: Enamel has a role as a semi permeable membrane and an ion - exchange. 1.2. Color of teeth and causes of teeth staining. 1.2.1. Color of teeth. Munsell color spectrum: Hue (h) is a property that allows distinguishing colors. Value (V) indicates the sensitivity or brightness of a color range from pure black to pure white. Chroma (C) is only the level of color saturation and intensity description, the intense or glare of the color. CIELa*b* color space: Light and dark axis value (L) is a unit of brightness of the object (L: 0 - 100), green - red axis value (a*) is the unit of measurement red (+a*) or green (-a*), blue - yellow axis value (b*) is the unit of measurement yellow (+b*) or blue (-b*). 1.2.2. The causes of tooth staining. 1.2.2.1. Extrinsic stain. 1.2.2.2. Intrinsic stain. 1.2.3. Tetracycline stained teeth. 1.2.3.1. Epidemiology: Tetracycline staining in the world community as well as in Vietnam is quite high. 1.2.3.2. Mechanism of tooth discoloration caused by tetracycline staining: Tetracycline molecules combine organic chassis to create a insoluble and stable compound which leads to discoloration of enamel and dentin structure. Light causes oxidasation to yellow in tetreacycline stained teeth and forms purple color. 1.2.3.3. Clinical characteristics of tetracycline stained teeth. Jordan and Boksman (1984) showed that lesions are yellow striped lines, corresponding to development lines in dentin scale and creating yellow 3 3 4 fluorescence trips under ultraviolet light. Tetracycline stained teeth were divided into 4 degrees. 1.3. Effectiveness of vital bleaching. 1.3.1. Whitening agent. 1.3.1.3. Mechanism of whitening agent: In bleaching process, H 2 O 2 is a final product. H 2 O 2 diffuses through the organic matrix of the enamel, dentin and decomposing into free radicals (HO 2 *, HO*, O*) with single electrons, they have enormous energy and instability and they will combine with organic molecules to achieve stability. So pigments can be broken from large molecules into small molecules and they could be removed easily by diffusion of substances into simpler molecules that reflect less light therefore they obtain bleaching effectiveness. 1.3.2. Vital bleaching methods 1.3.3. Studies of vital bleaching results in the world and in Vietnam 1.3.3.1. In the world: Summary of clinical studies and in vitro experiments has shown that: Safety and efficacy of general bleaching teeth and particular tetracycline stained teeth focuses on at-home bleaching techniques. Several case reports in-office tetracycline stained teeth bleaching gave good results at the end of treatment period, but time tracking was not long enough, there was not any systematic study and there was not any safe and effective protocol applied for a vital teeth by tetracycline staining bleaching protocol on the enamel morphological issued. Therefore, the research required to clarify this issue. 1.3.3.2. Vietnam: Until now, in Vietnam there were not any reports on effective vital bleaching tetracycline stained teeth systematically and comprehensively on clinic and experiment. Chapter 2. STUDY OBJECTS and METHODOLOGIES The study consists of 2 components: Clinal and experimental components. 2.1. Clinical design 2.1.1. Research object 2.1.1.1. Inclusion criteria: The patients with degree I and II tetracycline stained teeth (Classification I by Jordan and Boksman: Uniform light yellow, brown, or gray stain confined to incise three quarters of the crown, B3 - B4 corresponding. Classification II: Deep yellow, brown or gray 4 4 5 stain, without banding in cervical tooth, C3 - C4 corresponding). Incisors and premolars are not enamel hypoplasia. Irrespective of sex and age, age: over 18. History of using tetracycline before 12 years. As citizens of Vietnam. Patients who agreed to cooperate in the study. 2.1.1.2. Exclusion criteria: More sensitive teeth. Incisors have been falling gingival and cervical opening. Allergy to any component of bleaching agents. The patients have teeth staining but filled composite, cosmetic prosthesis for incisors. Teeth stains due to other causes. Degree III and IV tetracycline stined teeth. Enamel hypoplasia. More teeth decay. Pregnancy and breast feeding. The patients who have acute systemic diseases. Children under 18 years old. History of prior tooth whitening. Incisors had endodontic treatment. 2.1.2. Research location & time Research location: Institute of Odonto - Stomatology under Ha Noi Medical University, National hospital of Odonto - Stomatology. Dental of 108 Military Central hospital. Time: From 01/ 2010 to 01/ 2013. 2.1.3. Research methodologies 2.1.3.1. Research design Intervention of uncontrolled clinical trials, the following before - after comparison time series at 8 times. 2.1.3.2. Research sample Using formula for comparison of 2 rates. p 1 value is the proportion of patients with good results at the begin of treatment (p 1 = 0 for all patients in a state that not color well), prognosis for rate change after each intervention was 20% of patient will improve your teeth situation (p 2 = 0,2), the intervention is 3 times. z (1- α/2) : The trusted coefficient at probability rate 95% (= 1,96). 1-β : Sample force (= 90%) 5 5 6 p : (p1+p2)/2. n = 37. The research conducted stratified analysis of treatment effectiveness in 2 groups of degree I and II tetracycline stain (sample size for each degree tetracycline stain), so sample size is counted as 74, actually, the sample size of this study was 78. 2.1.3.3. Sample selection In each group of degree I and II tetracycline stain, the study selected randomly patients who satisfied with above criteria and consented to participate in this research. 2.1.4. The study protocol 2.1.4.1. Making information gathering forms 2.1.4.2. Clinical examination Classification of patients with degree I and II tetracycline stained teeth according to above criteria. 2.1.4.3. Steps of bleaching Step 1: Against sensitive dentin by sucking toothpaste with 5% KNO 3 (Sensodynefresh Mint) before 30 minutes. Step 2: Prepare (protect lip, cheek, eyes, and mucosa). Step 3: Enamel opening 5 minutes. Step 4: (cycle 1) Put the gel 35% H 2 O 2 (9 minutes). Step 5: Repeat step 4 except the default projector lamp for 8 minutes in cycle 2 and 3. Step 6: Finishing of treatment cycle. Step 7: Evaluate results immediately after treatment. Step 8: Directive patients. Performing is 3 phases, 1 week after the other each (phase 2 and 3 do not use enamel opening). Finishing of bleaching protocol: Brushing your teeth with toothpaste demineralization (Colgate sensitive Pro - Relief) 4 weeks. 2.1.5. Assessing the effectiveness of treatment 2.1.5.1. Evaluation of color change The indicators change color in the Munsell color spectrum and CIELa*b* color space: ∆C, ∆h, ∆V, ∆b*, ∆L, ∆a*, ∆E. According to American Dental Association, the gold standard for assessing the effectiveness of whitening products is ∆E ≥ 4. 2.1.5.2. Assessing the result of treatment Based on these criteria: Color change according to Vita and the side effects of the bleaching products (sensitive, mucosal and gingival lesions) and level of satisfaction of patients, this study divided the good, rather and 6 6 7 average results. Each patient has a follow-up vote bleaching protocol and recorded after each follow - up visit. 2.1.6. Research variables: The independent variable is the individual characteristics of the patient. Dependent variable: Munsell color spectrum (V, C, h) and CIELa*b* color space (L, a*, b*) in the first votes. The color change in the Munsell color spectrum and CIELa*b* color space ∆C, ∆h, ∆V, ∆L, ∆a*, ∆b* và ∆E in the nexts. 7 evaluations. Evaluation treatment outcome: Good, rather, average. 2.1.7. Patient observation, management & study data collection Data collection through 8 evaluations: Before treatment, treatment 1 st , 2 nd , 3 rd , 3 weeks, 3 months, 6 months, 12 months through measure indicators repeated by Vita Easyshade compact. Observation and examination were done according to the above criteria. Data were recorded in details on monitoring forms. 2.2. Experimental research 2.2.1. Research objects 2.2.1.1. Inclusion criteria: Tetracycline stained teeth, premolars and incisors were extracted for orthodontic reason, inflammation periodontal, the root teeth completely closed, the teeth are not decay, not cracked, not filled, age between 18 to 45 years. 2.2.1.2. Exclusion criteria: Teeth stain due to other causes, the teeth are decay, cracked, filled, enamel hypoplasia, the root teeth imcompletely closed. 2.2.2. Research location & time Research location: Institute of Odonto - Stomatology under Ha Noi Medical University, National hospital of Odonto – Stomatology, Dental of 108 Military Central hospital, 69 Hospital - The Steering Command. Time: From 01/ 2010 to 01/ 2013. 2.2.3. Research method Research design: Experimental study, morphology description under the SEM. Sample size: Using all of teeth was extracted and achieved above criteria. This study was 95 teeth. Sample choice: Randomized divide into 3 groups. 2.2.4. Study process 7 7 8 Encryption 3 groups: Group 1: Bleaching with 35% H 2 O 2 , and immersion in artificial saliva. Group 2: Bleaching with 35% H 2 O 2 , immersion in artificial saliva, brushing your teeth with SensodyneFresh Mint toothpaste daily. Group 3: Bleaching with 35% H 2 O 2 , immersion in artificial saliva, brushing your teeth with SensodyneFresh Mint toothpaste daily and bleaching finish brushing your teeth with Colgate sensitive Preo –Relief 2 weeks. Research on SEM: After an experiment done, teeth samples were fixed in aluminum column for SEM evaluations and then dehydrated, dried in the environment at 37ºC (room temperature) in a closed tank with silica gel for about 12 hours, samples then were fixed into a base and covered with gold (deskII, Dentor Moorestown, NJ, United States) for 80 seconds and examined under SEM (JEOL, Tokyo, Japan) with voltage 15 KV. Analysis of the results, comparison between the bleached enamel and control group in the magnification x750, x1500, x2000. 2.2.5. Assessing the result According to Le Van Son et al (2011) change in the enamel surface following lesion degree into 4 types: No lesion (degree 0): No change in the enamel surface in the control group. Mild lesion (degree 1): Dominantly, enamel surface morphology changed slightly, alternating as the change of middle and rare severity. Injury medium (degree 2): Dominantly, the teeth surface morphology changed middle, alternating as the change of light and severity changes. Severe lesion (degree 3): Dominantly, the teeth surface morphology changed severity, alternating as the change of light and moderate. Treatment efficacy: Efficacy: Enamel surface morphology unchanged or slightly (degree 0 and degree 1). No efficacy: Enamel surface morphology changed with moderate and severe (degree 2 and degree 3). 2.2.6. Study variables: Dependent variables: Change in the enamel surface following lesion degree into 4 types: No lesion (degree 0), Mild lesion (degree 1), Injury medium (degree 2), Severe lesion (degree 3). Treatment efficacy: Efficacy and no efficacy. 2.3. Remedies error: Measures to be applied to limit errors from sampling, using Easyshade compact colorimetric, and data processing. 8 8 9 2.4. Data processing: Data were collected and analyzed by the method of biostatistics, using SPSS 16.0 software and statistical algorithms. 2.5. Ethic research: Before enrolled in this study, all patients were fully explained, thorough. Patients were understood the results and side effects that might occur. Patients were understood the bleaching protocol, and agreed to receive treatment and to follow procedures. Patients voluntarily signed for the study participation. The information collected by the patients was kept confidentially and was only used for research purposes. This research applied to improve the aesthetics and health protection for patients but not for other purposes. 9 9 10 Chapter 3. RESEARCH OUTCOMES 3.1. Clinical characteristics of degree I and II tetracycline stained teeth 3.1.1. General characteristics of study subjects Total of 78 patients were studied: Percentage of female patients (78.2%) was higher than male patients (21.8%). A group of age 20 - 29 (20.5%) was lower than a group of age 30 - 45 (79.5%). The rate of degree II tetracycline stained teeth in a group of age 30 - 45 was 97.4%. Degree II tetracycline stained teeth was mainly in a group of age 20 - 29 (15/16 cases). 3.1.2. Clinical characteristics degree I and II tetracycline stained teeth Table 3.5. Distribution of colors in the Munsell (C, h, V) color spectrum according to dental groups Dental group n V C h ± SD ± SD ± SD Incisor 78 13,2 ± 1,8 27,8 ± 4,3 79,4 ± 4,9 Canine 78 15,5 ± 0,5 31,6 ± 5,8 75,9 ± 4,2 Premolar 78 12,1 ± 1,7 23,8 ± 3,7 81,7 ± 2,9 p (ANOVA test) < 0,01 < 0,01 < 0,01 General 78 13,6±1,2 27,7±4,3 80,0±3,8 Vita V, Chroma C: Canines were highest and premolares were lowest, there was statistical significant (p<0,01). Hue h: Canine were lowest and premolar were highest, there was statistical significant (p<0,01). Table 3.6. Distribution of colors in the CIELa*b* color space according to dental groups Dental group n L a* b* ± SD ± SD ± SD Incisor 78 71,0 ± 4,2 5,0 ± 1,9 27,3 ± 4,4 Canine 78 65,4 ± 6,5 7,2 ± 1,4 30,6 ± 6,0 Premolar 78 73,2 ± 3,6 3,3 ± 0,9 23,5 ± 3,8 p (ANOVA test) < 0,01 < 0,01 < 0,01 General 78 69,9±4,6 5,2±1,3 27,1±4,4 10 10 [...]... satisfied than the improvement seen the eye (can be considered significant) level II of tetracycline contamination This study also found the first bleaching tetracycline stain 2nd most drab yellow, while the second tetracycline infection despite many changes color but still light brown gray red yellow tetracycline So with tetracycline tooth infection, the degree of color change did not meet the treatment... quite tetracycline contamination levels I, for women and group of age 20 - 29 This also makes sense because the group of age 20 - 29 in this study mainly tetracycline contamination level of I The color changes in tetracycline teeth type I moderate can bring satisfaction to patients easier than type II Such a result was entirely consistent Results the 2nd times treatment: Good results focus on group tetracycline. .. (2004), this can be explained as follows: Tetracycline antibiotics appeared in 1948 and was used in Vietnam, popular in the late 60s and 70s So tetracycline prevalence in the group of age over 30 was high After 80 decades of the 20th century there was a warning about the color of tetracycline contamination should doctors and patients more aware when using tetracycline limit for children under age 12... difference The colors Vita V: Degree I tetracycine stained teeth: yellow - gray - light brown level Degree II tetracycline stained teeth: yellow - gray - darker sepia level, the difference was statistical significant Chroma of degree I tetracycline stained teeth (81.4) correspond to orange, tetracycline teeth degree II (76.6) correspond to red gray yellow This result was similar to that of Jordan and... specific parameters for each chromosome level, while this study gave specific indicators for each level of chromosomal tetracycline The clinical features will help the dentist to have a treatment plan specific to tetracycline exposure 4.2 Assess the effectiveness of the vital bleaching tetracycline stained teeth 4.2.1 Evaluation of tooth color change 4.2.1.1 Rating changes color according to Munsell color... units tetracycline stained teeth to bring 20 21 21 new satisfaction for dentists and patients In this study, 2 nd post-treatment colors mean reduction of 6.5 units should continue 3 rd therapy and results were expected by dentists and patients According to Bowler et al (1997) that the reason chromosomal tetracycline to treat prolonged or repeated treatment at the clinic was able to generate by tetracycline. .. be explained as follows: Tetracycline and its peer agents capable of forming complexes with calcium ions on the surface of the hydroxy apatite crystals in bone and 18 19 19 tooth tissue Darker dentin enamel discoloration Light tetracycline oxidized quinone create red Group teeth before exposure to light easily and easily change colors than the group that later Distribution of tetracycline discolored... For tetracycline teeth type I and younger patients easily accept change color just right The color change of the average Vita II levels decreased more than the I In considering the criteria synthetic color changes, medication side effects and satisfaction of patients and found that good results in a higher tetracycline type I than type II in the treatment second This result was explained as follows: tetracycline. .. parameters To have beautiful white teeth for patients with tetracycline teeth the dentist should be noted when applied to teeth bleaching time for each tooth to bring the best whitening results after bleaching to achieve similar parameters Distribution colors in the Munsell color spectrum and color space based on the degree of tetracycline stain: Degree I tetracycline teeth have the lighter color and higher... improve the 9 - 10 units colors with the tetracycline stained tooth really bring satisfaction to the patient So we continue to treat the 3rd times to meet the treatment needs of patients Results of the 3rd times treatment: Results of the general good research subjects was 96.1%, 3.9% was pretty Tetracycline stained teeth type I have good results (94.9%) lower than tetracycline stained teeth type II (97.4%) . people who are being suffered by tetracycline stained teeth. How is clinical characteristics of degree I and degree II tetracycline stained teeth? How efficacy do tetracycline stained teeth bleach?. II tetracycline stained teeth. Identified indicators of the Munsell color spectrum and CIE La*b* color space for each degree of tetracycline stain. 2. Affirm vital bleaching treatment for tetracycline. stain. 1.2.3. Tetracycline stained teeth. 1.2.3.1. Epidemiology: Tetracycline staining in the world community as well as in Vietnam is quite high. 1.2.3.2. Mechanism of tooth discoloration caused by tetracycline