Summary of medical doctoral thesis: The impact of operating microscope on the outcome of endodontic treatment in first maxillary molar

Describe the clinical and radiological features of the upper first molar indicated for endodontic treatment; assessing the effectiveness of microscope application in the treatment of upper first molar; evaluation of the results of the upper first molar’s endodontic treatment.

MINISTRY OF EDUCATION & TRAINING MINISTRY OF HEALTH HANOI MEDICAL UNIVERSITY BUI THI THANH TAM THE IMPACT OF OPERATING MICROSCOPE ON THE OUTCOME OF ENDODONTIC TREATMENT IN FIRST MAXILLARY MOLAR Specialty : Odonto and Stomatology Student No : 62720601 SUMMARY OF MEDICAL DOCTORAL THESIS HA NOI - 2020 WORK IS COMPLETED AT: HANOI MEDICAL UNIVERSITY Scientific supervisor: Ph.D Nguyen Manh Ha Asso.Prof Ph.D Pham Thi Thu Hien Opponent Opponent 2: Opponent The thesis will be defended before school level Jury at Hanoi Medical University You can learn about the thesis in: National Library Library of Hanoi Medical University PROBLEM STATEMENT With the development of science and technology, microscopes have also been applied in dentistry in many countries around the world Many scientific works have shown the outstanding advantages of microscopes applied in dentistry The use of endodontic microscopes helps to identify symptoms, diagnose the disease correctly, and detect the root canal more easily With the remarkable advantages of the microscope in terms of magnification and focus, the microscope really opens a new era for dentsitry in general and Endodontic in particular In Vietnam, the research and application of microscopy in endodontic treatment is still limited In order to evaluate the applicability of microscopes in dental treatment of endodontics, we conducted the study "Study of microscopy application in root canal treatment of upper first molar" with the following objectives: Describe the clinical and radiological features of the upper first molar indicated for endodontic treatment Assessing the effectiveness of microscope application in the treatment of upper first molar Evaluation of the results of the upper first molar’s endodontic treatment The need of the study Endodontic diseases always make up a high proportion in dental diseases Endodontic treatment is an important area of restorative dentistry to restore function and aesthetics to diseased teeth The upper first molar is one of the earliest erupted teeth and has the most endodontic treatment, but the rate of failure of endodontic treatment is the highest among the molar teeth Many studies show that the presence of MB2, as well as unsatisfactory cleaning of the pulp chamber, is the main cause of treatment failure Therefore, the application of technical advances such as dental microscopes to detect root canals, wall crevices, pulp chambers, granules and calcified blocks is extremely necessary to support the dentist in detect, clean, shape the canal, and pulp chamber treatment New contributions of the study - This is a research project following the new trend of microscope application in the accurate diagnosis and examination of fissures before and during treatment, the discovery of calcified particles and calcification chamber, and management of complications when encountered in the treatment of upper first molar - The thesis specifically evaluates the efficiency of using a microscope to detect the orifice of the root canal, of which the most effective is to detect the MB2 is much higher than naked eye - The results of the study are monitored up to 24 months after treatment, which is long enough to generalize the results, making recommendations in the application of microscopes in endodontic treatment Layout of the thesis The thesis has 143 pages, including sections: problem statement (2 pages), introduction (44 pages), subjects and research methods (18 pages), results (47 pages), discussion (29 pages), conclusion (2 pages), Suggestion (1 pages), The thesis has 49 tables, 47 pictures, charts, diagram 131 references including Vietnamese and English documents CHAPTER 1: INTRODUCTION 1.1 Anatomy of the upper first molar root canal system The upper first molar is the earliest permanent tooth, so it is the first to decay Upper first molar has three root: two buccal root (MB and DB) and one platal root Each root corresponds to root canal, sometimes canals, usually found in the proximal canal 1.1.1 Outer anatomy Viewed from the occlusal surface: The contour is usually diamond shape Three large cusps form a typical pattern for maxillary molar teeth, which are linked together into a triangle These are important anatomical landmarks applied when opening pulp for endodontic treatment of the upper fist molar teeth 1.1.2 Inner anatomy The inner form includes the pulp chamber and the canal system 1.1.2.1 Pulp chamber On the near and far view: the pulp chamber has two horns, the horn is near the outside and the horn is far away The two canals are quite narrow On the external outer view: the pulp chamber is wider, the horn of the pulp is usually protruding Usually has legs with root canals The proximal canal is shorter than the inner canal, the proximal canal is usually very wide and in most cases there is an additional root canal On a view across the pulp chamber in the neck of the tooth: the shape of the pulp chamber in the neck of the tooth is shaped like a parallelogram * The pulp chamber ceiling is the upper limit of the pulp chamber, usually far from the floor in young people and is lowered in the elderly due to the development of dentine as well as mechanical and chemical stimuli * The pulp floor is the lower limit of the pulp chamber, on the floor of the pulp chamber has an opening of the root canal However, the calcification of the pulp chamber makes it difficult for endodontic treatment, the orifices can be obscured making it more difficult to access the pulp chamber and the risk of instrument fracture This phenomenon is quite common in root canal 1.1.2.2 Root canal system The root canal system starts from the orifice of the root canal at the floor of the pulp chamber and ends at the end apex There are or root canals forming triangles with acute distal angle The root canal system in the upper first molar is analyzed by the Weine classification system, most teeth have roots, each root usually has root canal, the additional root canal is MB (79.2%) and DB (1.65%) 1.1.3 The study of internal anatomy of teeth Laboratory or clinical studies to describe internal anatomy include many different types of methods 1.1.4 Some landmarks open marrow anatomy application The entry point to the pulp chamber of upper first molar starts from 1-2mm from the MB cusp towards the central groove, using a round drill or Endo access to open into the pulp chamber According to Hess, the opening is a trapezoid shaped narrower than the pulp floor In the case of not seeing the orifice, open the chamber further and follow the mesial diagonal 1.2 Pathology of dental pulpal and periapical disease Causes: bacterial infection, physical factors Classification of the pathology and diagnosis is based on clinical and paraclinical symptoms according to the American Endodontic Association recommendations for use in 2008 Diagnosis of pulpal disease: Classification of pulp pathology is mainly based on clinical signs, subclinical and physical symptoms Periapical disease: include acute, subacute or chronic lesions Injury area usually refers to lesions in the ligament and bone region around the apical area 1.3 Endodontic treatments: Conservative treatment (Pulp capping Partial pulpotomy), root canal treatment 1.4 Some causes of failure in endodontic treatment: Opening wrong path, broken instrument, obturation over apex 1.5 Microscope application in endodontic treatment and treatment results 1.5.1 Introducing the microscope A microscope is a device for viewing very small objects that are invisible to the naked eye The visibility of a microscope is determined by its resolution Advantages of magnifying devices: The three main advantages identified are related to the use of endodontic amplification devices, that is, (1) a clearer working field, (2) improved working posture and (3) increased persuasion ability Disadvantages of microscopes Some of the reported drawbacks are the time it takes to get used to new equipment, the cost of magnification equipment and related accessories, the need for additional infection control, and possibly injury due to the sharp instruments 1.5.2 Some research results using microscopy in endodontic treatment Several studies have shown that it significantly increases the ability of dentist to locate and access the root canal Therefore make the results of treatment increase CHAPTER 2: MATERIALS AND METHODS 2.1 Materials Maxillary first molars which needed endodontic treatment, were treated at Department of Endodontics, National Hospital of OdontoStomatology from January 2013 to April 2019  Inclusion criteria - Maxillary first molar needed nonsurgical endodontic treatment - Restorative management is available after root canal treatment - Patients accepted - Mature teeth  Exclusion criteria - Patients with severe diseases: cardiovascular diseases, hypertension, diabetes, psychiatric diseases - Patients unaccepted 2.2 Methods 2.2.1 Method: thepary study with intervention 2.2.2 Sample size and selection  Sample size n: minimum sample size : α = 0,05 = 1,96 p: Prevalance of success endodontic treatment (90%) After calculating, n=97 In fact, we treated 105 maxillary first molars Sample selection: satisfactory All the patients with inclusion criteria were screening, explained and invited to participate We collect until adequate volume 2.3 Procedures Information collected Examine, pulp testing (with microscope) X-ray: periapical view Diagnosis, etiology Anesthesia Rubber dam Pulp access Identify orifice Eyes vision Microscope Irrigation and shaping Obturation Restoration Follow - up 2.4 Diagnosis and treatment 2.4.1 Symptoms and Xray - Reasons - Symptoms + Pain/no pain + Pain level - Examine + Fever/no fever + Swelling/no swelling + Soft tissue: red, swelling, painful when press, sinus tract + Hard tissue: caries dectection, cracked teeth (by eyes and microscope) - X-ray: periapical view - Diagnosis: pulp diseases, periapical diseases - Protocol: base on the protocol that AAE recommend in 2008 2.4.2 Treatment Treatment procedure - Anesthesia: local (vital pulp) - Wall build –up (if needed) - Place rubber dam - Access - Observe pulp chamber: calcification or not, cracked line (by eyes and microscope) - Detection and shaping (2 phases) Phase 1: Identify orifice by endodontic explorer and eyes Take photos of pulp floor Phase 2: Identify orifice by endodontic explorer and microscope After finding the forth or fifth orifice, continue to: - Open - Identify working length - Shaping by rotary files Protaper - Cold lateral compaction and warm vertical compaction - Master cone fit radiograph - Restoration - Follow up 2.4.2.3 Results * After obturation on Xray Good Standard Adequate Final working length master (apex or 0,5mm cone shorter) length -Well condensed Average -Underextension 12mm or overexthension ≤ 1mm - Bad condensed Bad Underextension >2mm or or overexthension ≤ >1mm * Post-op afer week Symptom Bite Soft tissue Good Normal No swelling Average Mild pain No swelling Percussion No pain Mild pain Bad Can not bite Red, swelling, pain when press Sharp pain * Post-op after 3-6 months, 12 months and years: Examine, Xray Xray Outcome Symptoms -Bite: normal - No periapical lesion -No pain, no swelling - Apical lesion: smaller Good - Percussion: no pain -Bite: normal Periapical lesion: no change Average -No pain, no swelling - Percussion: mild pain -Bite: pain Periapical lesion: bigger -pain, swelling Bad - Percussion: pain 2.6 Errors and error corrections 2.6.1 Errors 2.6.2 Error corrections 2.7 Data processing: STATA 15.1 softwar 11 Table 3.9 Images of the pulp chamber and the periapical X-ray by age group Age 44 Total Xray (n=17) (n=41) (n=47) (n=105) Without 16(94,1) 21 (51,2) (14,9) 44 (41,9) Pulp calcification chamber (5,9) 20 (47,8) 40 (85,1) 61 (58,1) Calcified 16(94,1) 31 (75,6) 33 (70,2) 80 (76,2) Normal Periapical (5,9) 10 (24,4) 14 (29,8) 25 (23,8) Lesion - On the x-ray image, the proportion of calcified chamber was 51.8%, increased significantly with the increasing age groups, respectively, the age group 44 years old is 85.1% The difference was statistically significant with p 44 years and 29.8%, then to the group of 30 -44 years old with 24.4% and the lowest was the group 44 years of age is 12 70.2%; group of 30-44 years old is 53.6%; The group