Tóm tắt Luận án The impact of operating microscope on the outcome of endodontic treatment in first maxillary molar

ased 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. 5 CHAPTER 2: MATERIALS AND METHODS 2.1. Materials Maxillary first molars which needed endodontic treatment, were treated at Department of Endodontics, National Hospital of Odonto- Stomatology 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. 6 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 7 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 8 2.4.2.3. Results * After obturation on Xray Standard Good Average Bad Final master cone length - Adequate working length (apex or 0,5mm shorter) -Well condensed -Underextension 1- 2mm or overexthension ≤ 1mm - Bad condensed Underextension >2mm or or overexthension ≤ >1mm * Post-op afer 1 week Symptom Good Average Bad Bite Normal Mild pain Can not bite Soft tissue No swelling No swelling Red, swelling, pain when press Percussion No pain Mild pain Sharp pain * Post-op after 3-6 months, 12 months and 2 years: Examine, Xray Outcome Symptoms Xray Good -Bite: normal -No pain, no swelling - Percussion: no pain - No periapical lesion - Apical lesion: smaller Average -Bite: normal -No pain, no swelling - Percussion: mild pain Periapical lesion: no change Bad -Bite: pain -pain, swelling - Percussion: pain Periapical lesion: bigger 2.6. Errors and error corrections 2.6.1. Errors 2.6.2. Error corrections 2.7. Data processing: STATA 15.1 softwar 9 2.8. Ethical aspect of research * Ethics in research The research was allowed by the Council of PhD, School of Odonto-stomatolgy, Hanoi Medical University. It is also accepted by the Director of National Hospital of Odonto-Stomatology. All the patients included was explained clearly about the purpose, meaning, benefit and risk of this research. All the information and data collected is protected and used only for this research. CHAPTER 3: RESULTS 3.1. Clinical and X-ray characteristics of the maxillary first molar before treatment Table 3.1. Distribution of study population by age and gender Gender Age Male n (%) Female n (%) Total n (%) <30 8 (13,1) 9 (20,4) 17 (16,2) 30 - 44 23 (37,7) 18 (41,0) 41 (39,0) >44 30 (49,2) 17 (38,6) 47 (44,8) Total 61 (100) 44 (100) 105 (100) The percentage of subjects in the study increased gradually by age group, respectively: 16.2%, 39.0%, 44.8%. This difference is statistically significant with p <0.05 Table 3.2. Distribution of reasons for visit by age Age Reason <30 n (%) 30 – 44 n (%) >44 n (%) Total n (%) Pain 14 (82,4) 33 (80,5) 31 (66,0) 78 (74,3) Swelling and pain 3 (17,6) 6 (14,6) 16 (34,0) 25 (23,8) Other 0 (0,0) 2 (4,9) 0 (0,0) 2 (1,9) Total 17 (100) 41 (100) 47 (100) 105 (100) The reason patients coming to visit due to pain was the highest proportion (74.3%), due to swelling and pain was 23.8% and due to other reasons was only 1.9%. The difference was statistically significant with p <0.05. 10 Table 3.5. Distribution of causes by age group Age Cause <30 n (%) 30 – 44 n (%) >44 n (%) Total n (%) Decay 15 (88,2) 18 (43,9) 14 (29,8) 47 (44,8) Cracked tooth 2 (11,8) 21(51,2) 33(70,2) 56 (53,3) Other 0 (0) 2 (4,9) 0 (0) 2 (1,9) Total 17 (100) 41 (100) 47 (100) 105 (100) The tooth crack increases with age; in the group <30 is 11.8%, the age group from 30 - 44 is 51.2%, in the group of > 44 is 70.2%. In contrast, the incidence of tooth decay decreases with age. This difference is statistically significant with p <0.05. Table 3.7. Detection of tooth crack by visual examination and microscope by age group Age Method <30 n (%) 30 – 44 n (%) >44 n (%) Total n (%) Naked eye 1 (5,9) 21 (51,2) 27 (57,4) 49 (46,7) Microscope 3 (17,6) 29 (70,7) 40 (85,1) 72(68,6) Total 17 (100) 41 (100) 47 (100) 105 (100) - The highest sign cracked tooth can be found in the age group> 44 is 57.4%, in the group of 30 - 44 is 51.2%, in the group <30 years of age there is very little 5.9% when examine without microscope. The difference was statistically significant with p <0.05. - When examined under the microscope, the percentage of tooth cracked increased significantly in the group> 44 years old from 57.4% to 85.1%; 30 -44 age group increased from 51.2% to 70.7%; The group <30 years old increased from 5.9% to 17.6%. The difference was statistically significant with p <0.05 - By visual examination, 46.7% of teeth with cracked lines were discovered, when examination by microscope the percentage of cracked lines increased significantly to 68.6%. The difference was statistically significant with p <0.05. 11 Table 3.9. Images of the pulp chamber and the periapical X-ray by age group Age Xray <30 (n=17) 30 – 44 (n=41) >44 (n=47) Total (n=105) Pulp chamber Without calcification 16(94,1) 21 (51,2) 7 (14,9) 44 (41,9) Calcified 1 (5,9) 20 (47,8) 40 (85,1) 61 (58,1) Periapical Normal 16(94,1) 31 (75,6) 33 (70,2) 80 (76,2) Lesion 1 (5,9) 10 (24,4) 14 (29,8) 25 (23,8) - On the x-ray image, the proportion of calcified chamber was 51.8%, increased significantly with the 3 increasing age groups, respectively, the age group <30 years 5.9%, age group 30 - 44 years old 47.8% and the group >44 years old is 85.1%. The difference was statistically significant with p <0.05. - The rate of periapical lesion is 23.8%, the highest prevalence was in the age group of> 44 years and 29.8%, then to the group of 30 -44 years old with 24.4% and the lowest was the group <30 years with 5,9%. 3.2. The effectiveness of microscope application in the treatment of the maxillary first molar: Bảng 3.12. Detect cracks in the pulp chamber through the naked eye examination and microscopy by age group Age Method <30 n =17 30 – 44 n=41 >44 n=47 Total n =105 Naked eye Yes 1 (5,9) 12 (29,3) 14 (29,8) 27 (25,7) No 16 (94,1) 29 (70,7) 3 3(70,2) 78 (74,3) Microscope Yes 2 (11,8) 22 (53,6) 33 (70,2) 57 (54,3) No 15 (88,2) 19 (46,3) 14(29,8) 48 (45,7) - Proportion of crevices in the tooth pulp chamber increases with age when observed with the naked eye and a microscope:> 44 years of age is 12 70.2%; group of 30-44 years old is 53.6%; The group <30 years old is 11.8%. This difference is statistically significant with p <0.01. - The rate of detecting fissure in the wall of medullary chamber by microscopy in the corresponding groups is: group <30 years old eye is 5.9%, KHV is 11.8%, group 30-44 years old is usually 29 , 3% and KHV is 53.6%, the group> 44 years old eyes is 29.8% and KHV is 70.2%. This difference is statistically significant with p <0.01 Table 3.15. The rate of detecting discrete calcified particles with the naked eye and microscope by age group. Observed results show that the rate of discrete calcified particles tends to decrease with age when observed with the naked eye, especially when observed with a microscope. The results are 35.3% (age <30), 34.1% (age 30 - 44), and 20.5% in patients aged above 44 years. The difference was statistically significant with p <0.05. Thus, in people aged above 44 years, the proportion of discrete calcified particles is the lowest. The difference was statistically significant with p <0.05. Table 3.19. The rate of detecting calcified masses with the naked eye and microscope in pulp chamber by age group Age group Calcified masses <30 (n=17)(%) 30 – 44 (n=41)(%) >44 (n=47)(%) Tổng số (n=105)(%) Naked eye yes 2 (11,8) 20(48,8) 29 (61,7) 51 (48,6) No 15 (88,2) 21 (51,2) 18 (38,3) 54 (51,4) Microscope Yes 5 (29,4) 29 (70,7) 41 (82,3) 75 (71,4) No 12 (70,6) 12 (29,3) 6 (7,7) 30 (28,6) By visual examination, the rate of detecting calcified masses in pulp chamber gradually increases with age group, the lowest is the group under 30 years old (11.8%), the group of 30-44 years old is 4 times higher (48.8%), especially those over 44 years old accounted for the highest percentage (61.7%). Similarly, the results of microscopic examination in each age group, the rate of detection calcified masses also increased significantly in each age group, 13 increasing by 29.4%, 70.7%, 82.3%, respectively. The difference in the proportion of calcified masses in pulp chamber by age group was statistically significant with p <0.05. - Detecting calcified masses markedly increased with 2 different observation devices. The group aged under 30 years increased from 11.8% to 29.4%; In the group of 30-44 years old, from 48.8% increased to 70.7%, in the group aged above 44 years old from 61.7% increased to 82.3%. The difference was statistically significant with p <0.05. Table 3.24. The position of MB2 orifice detected by the naked eye and microscope Means Position Naked eye n(%) Microscope n(%) On the groove connecting MB1 and palatal canal 9 (26,5) 23 (25,3) Deviate mesially from the groove connecting MB1 and palatal canal 26 (76,5) 68 (74,7) Total 34 (100) 91 (100) The number of MB2 orifice at the position that deviated mesially to the connection between the MB1 and palatal canal is three times as many as that of MB2 orifice located on the connecting groove between MB1 and palatal canal in both visual and microscopic observations: 26.5% versus 76.5% and 25.3% compared to 74.7%, respectively. - The position of MB2 orifice is on the groove connecting MB1 and palatal canal when using the microscope to see more clearly than using the naked eye from 9 cases to 23 cases. The position deviated mesially also increased when observed under the microscope, increasing from 26 to 68 cases. - The total position of MB2 orifice also increased markedly when observed under the microscope, increasing from 34 to 91 cases. 14 3.3. Treatment results of maxillary first molar using a microscope Table 3.34. Treatment results after one week by age group Result <30 n (%) 30 – 44 n (%) >44 n (%) Total n (%) Good 13 (76,4) 33 (80,5) 43 (91,5) 89 (84.8) Quite good 4 (23.6) 6 (14,6) 3 (6.4) 13 (12.4) Poor 0(0,0) 2 (4,9) 1 (2,1) 3 (2,9) Total 17 (100) 41 (100) 47 (100) 105 (100) After 1 week of root canal obturation, the rate of good results increases with age groups, 76.4%; 80.5% and 91.5%, respectively. This difference is not statistically significant with p> 0.05. - The rate of quite good results in the group under 30 years achieved the highest result, 23.6% and the lowest was the group above 44 years old. The rate of poor results in the group <30 years old is 0%, the group of 30- 44 is 4.9%, and the group of > 44 years old is 2.1%. The difference is not statistically significant with p> 0.05. Figure 3.6. Treatment results after 3 - 6 months (n = 96) 90.6% 5.2% 4.2% Tốt Khá Kém 15 - After 3-6 months of treatment, there were 96 patients coming to follow-up appointments, so we summarized and evaluated the treatment results on these 96 patients. - Up to 90.6% of patients healed and achieve good results after 3- 6 months. However, there are still 5.2% of patients who are recovering after this period of time with quite good results, still 4.2% of patients who have not healed and get poor results. The difference was statistically significant with p <0.05. Figure 3.7. Treatment results after 1 year (n = 88) - After 1 year of treatment, 88 patients came to the hospital by appointment. Thus, we evaluated the treatment results on 88 patients. - Up to 96.6% of patients achieved good treatment results, but still 1.1% achieved quite good results and 2.3% achieved poor results. Figure 3.8. Treatment results after 2 years (n = 87) - After 2 years of treatment, we re-examined 87 patients. - The proportion of patients achieving good results was 97.7%. There were 2 cases with poor results (2.3%). 96.6 1.1 2.3 Tốt Khá Kém 97.7 0 2.3 Tốt Khá Kém 16 CHAPTER 4: DISCUSSION Researching on 105 first maxillary molars were treated endodontically, we had some issues to discuss as follows: 4.1. Clinical and X-ray features of the first maxillary molar before endodontic treatment. 4.1.1. General information of research subjects In this study, the average age of the study subjects was 41.9 ± 11.9 (years). The proportion of patients in the group higher 44 age accounted majority, with 44.8%. The generality of study patients were male, accounting for 58.1%. The age of the study subjects (in both men and women) increased gradually by age group, the group over 44 years old have disease was highest with 44.8%. Our research results are similar to those reported by Pham Thi Thu Hien with the study participants aged over 40 accounting for the highest proportion (50%), the proportion of patients aged 20 - 40 is 45 % (p <0,001). 4.1.2. Clinical features of first maxillary molar before endodontic treatment Regarding the reason of medical visiting, in this study, our patients came to medical visit because of pain accounted for 73.4%, swelling and other reasons accounted for only 23.8%. In particular, the proportion of patients have pain in the group over 30 - 44 years old accounted majority was 82.4%. Swelling and pain is the reason for medical visit in the group of over 44 years old, accounting for 64% of cases. This result is similar to the report of Pham Thi Thu Hien when the author showed that the majority of patients come for medical visit by pain. According to diagnosis of the cause of the disease, the majority of causes of disease of the study subjects were caries and cracked teeth, tooth decay accounted for 44.8% and cracked teeth accounted for 17 53.3%. The rate of causes of tooth decay in our study is consistent with the author Cao Thi Ngoc (causes of tooth decay accounted for 55.7%). But lower than Nguyen The Hanh’s study caused by caries accounted for 95.1%, Tran Thi Lan Anh’s study caused by caries accounted for 80.6%, ... In our study, eye exams often found cracked teeth in 46.7% of cases, using a microscope to detect 68.6% of cases. Thus, the identification of cracked teeth when observed under a microscope will give higher results with the naked eye. In the group has the cause is pulp pathology by tooth decay accounted for 78.7%, periapical pathology accounted for 21.3%, the reason is that tooth fracture has pulp pathology is 73.2%, periapical pathology accounts for 26.8%. Pulpal pathology accounts for 75%, periapical pathology 25%. Our results are similar to those of Pham Thi Thu Hien that the pulpitis is the most common disease accounting for 48%. Similarly, author Muhammad Hasan Pakistan showed that the acute periodontal group had irreversible pulpitis symptoms accounting for 17%. 4.1.3. X-ray features of the first molars before treatment Our research results show that the proportion of calcified pulp chamber is 58.1%, the non-calcified pulp chamber is 41.9%. The higher the age has the higher of calcified pulp chamber image. The dental ligaments have a rate of relaxation also increases with age: 29.45%, 51.2%, 53.2%, respectively and the condition of periapical almost is normal. 4.2. Effective of microscope application in the endodontic treatment of the first maxillary molar. * With calcified teeth: In our study, patients with calcified pulp chamber in x-ray images accounted for 58.1%, but could not distinguish the type of 18 calcification. When the pulp chamber is opened and when observed under the microscope it is clearly seen that there are two types of calcification, sometimes discrete particles of calcium or continuous cement blocks associated with the structure of the pulp chamber wall. Therefore, identifying and eliminating them is difficult. Discrete images of calcified particles as observed by the naked eye have 13 cases accounting for 12.4% and observing under the microscope 29 cases accounting for 27.6%. When observed under a microscope, in the age group under 30 and 30-44 years of age, the proportion of discrete calcified particles accounting for high percentage is 35.2% and 34.1%, while in the age group over 44 years accounts for 19.1%. Our results are similar to those of Colak H and Celebi (2012) with the highest rate of scattered calcium in middle age, accounting for 76.24%. And in our study, the typical calcium block with the naked eye was able to see 51 (48.6%) cases, when observed under a microscope saw 75 (71.4%) cases and especially increased by age. Observations under the microscope show that the calcium image is more visible than the naked eye. * With cracked teeth: Our study has recorded that the group has the cause is pulp pathology by cracked tooth accounts for 52%, the higher the age, the more common ration of cracked tooth. Bajaj et al. found differences in micro features of the fractured surface between dentin in the elderly and young people. In this study, cracked teeth were commonly reported in people aged 50-59. In our study the male group accounted for 38 teeth, the female group was 17 teeth. But there are many studies in Korea do not show a difference in the number of cracked teeth between men and women. In our study, before the treatment, the visual examination detected 49 cases of cracked teeth, under the microscope detected 72 cases of 19 cracked teeth, of which signs of craze line detected 11.4%, by microscope 15.2%, signs of cracked tooth by naked eye 31%, by microscope 47.8%. Fractured cusp examination by naked eye and regular microscope also is 5.7%. Teeth that have been opened pulp chamber, observe the craze line on the walls of the pulp chamber, by the naked eye 25.7%, by the microscope 54.3%. * Identification the orifice of root canal: Our study results show that the number of canal discovered in clinic ranges from 2 to 5. In particular, the age group below 30 all found 4 canals. When observing by the naked eye, 100% of cases can observe 1 platal canal and have no case can observe 2 platal canals. When using a microscope, the number of cases that detect the second mesial buccal is 91, accounting for 86.7%. In addition, 4 further distal buccal canals were detected (3.8%). Our study results are similar to previous studies. Ajay Paliwal's author showed that 66.6% of cases of MB2 were detected with the naked eye. When using a microscope, 87.5% cases were detected more than naked eyes. * Combining the microscope with other means. Ajay Paliwal showed that when combined between microscope and clinical preparations, a total of 111 (92.5%) cases detected MB2. Ajay Paliwal also showed that using naked eye has a relatively low accuracy in diagnosis (from 75.8% to 77.5% respectively after stages 1 and 2). Using the microscope, the accuracy increased to 96.7% and 98.3% after stages 1 and 2. Vasundhara and Lashkari (2017) showed that the rate of detection of MB2 increased from 25% during examination by the naked eye up to 52.5% when using a dental magnifier and 68.3% when using cone-beam CT. The difference in MB2 detection rate between these techniques is statistically significant (p <0.001). In Vietnam, according to Pham Thi Thu Hien, the number of MB2’s orifice clinically detected by the naked eye is 20 the lowest of 18 orifices (18%), Phase II is supported by a magnifying glass and the detection rate has been raised up to 47% and after removing the secondary dentin and digging deep into the drain on pulp chamber floor, this percentage was increased to 77%. These difference is statistically significant with p <0.001. When comparing the left and right first maxillary molar, we also found that there is no difference in the ability to detect and prepare MB2. In 2007, Gary assessed the ability to detect MB2 clinically by 10 residents, observed 121 first maxillary molar teeth including 85 teeth (70.2%) with four canals. The ratio of MB2 in our study is similar to this study. Analyzing the relationship between age and number of MB2, we also found that under the age of 30, the rate of MB2 was the highest at 94.1%, at the age of over 44 was the lowest. This result is also consistent with the physiological and pathological characteristics of the teeth. Also according to Suroopa Das (2015), the higher the age, the less chance to detect MB2. * The location of the second mesial buccal orifice. Our results show that the majority of MB2 orifices are located at a mesial position with 26 patients, accounting for 76.5%. Only 8 patients had MB2 orifice at the position on the line connecting MB1 and platal canal orifice, accounting for 23.5%. Most of MB2 orifice rates are in the mesial deviation position. The number of clinically observed canals ranged from 2 to 4. Using microscopes with means to support the detection of 3 - 5 canals. Das S studied over 150 permanent maxillary molars in 2015, found that: On average, the secon