MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENCE 108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES PHAM TUAN ANH RESEARCH IMMEDIATE IMPLANT PLACEMENT AND EVALUATE THE RESULTS AFTER P[.]
MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENCE 108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES PHAM TUAN ANH RESEARCH IMMEDIATE IMPLANT PLACEMENT AND EVALUATE THE RESULTS AFTER PLACEMENT Speciality : Odonto-Stomatology Code : 62.72.06.01 ABSTRACT OF MEDICAL PHD THESIS HANOI - 2022 The thesis was done in 108 Institute of Clinical Medical and Pharmaceutical Sciences Supervisors: Assoc Prof Ta Anh Tuan PhD Trinh Hong My Reviewer 1: Assoc Prof Truong Uyen Thai Reviewer 2: Assoc Prof Tran Cao Binh This thesis will be presented at Institute Council at: 108 Institute of Clinical Medical and Pharmaceutical Sciences At hour , date month year 20 The thesis can be found at: National Library of Vietnam Library of 108 Institute of Clinical Medical and Pharmaceutical Sciences INTRODUCTION Replacement of missing teeth using dental implants has proven to be a popular, successful treatment procedure However, this technique has limitations when the waiting time is long, the local bone volume is lost which is not enough for implantation and requires multiple surgeries Therefore, this method of immediate implant placement after tooth extraction has gradually become more popular with the advantages of reducing the number of surgeries, limiting bone loss, improving implant placement, easy positioning of bone drills, and preserving soft tissue However, immediate placement has limitations such as large alveolar bone size, often difficulty to achieve primary stability because of poor bone density and a small number of bones; difficulty to close the flap to cover the implant Therefore, immediate placement remains a challenge, with many influencing factors Healing time and implant stability are difficult to predict and must be determined prior to restoration Many authors have shown that implant stability is correlated with factors such as bone density, insertion torque, and bone defects around the implant But no studies have shown the degree of correlation affecting implant stability and how to calculate the required healing time in immediate placement Stemming from the above fact with the study of the correlation between factors affecting the healing time, and implant stability, we conduct the project: “Research immediate implant placement and evaluate the results after placement” with two following objectives: 1/ Describing clinical and radiographic characteristics of the teeth with indications for immediate placement 2/ Evaluating immediate placement results and identify some factors related to healing time and implant stability * The necessity of the project Immediate placement has been becoming more and more popular, it has overcome a number of disadvantages in terms of waiting time, number of surgeries, easy positioning of bone drill, and preservation of soft tissue However, this method still has limitations such as the size of the alveolar bone, and the implant is often not suitable, often not achieving the desired primary stability The stability of the implant is affected by bone density, insertion torque, and bone defects around the implant But no studies have shown how strong or weak the correlation affects implant stability and how to calculate the required healing time in immediate implants Therefore, this project has scientific, topical, and practical significance, contributing to the profession * Practical meanings and new contributions Research results show that immediate placement can be successful in all tooth regions when selected appropriately However, caution should be exercised with the molar region when making single prostheses, especially with the maxillary molars This project has shown that there are many correlated factors affecting the implant stability, the healing time and has given two formulas to calculate the healing time, the implant stability in the immediate placement based on known factors This is a new point in both theory and practice in the field of implants in particular and in the field of OdontoStomatology in general * Structure of the thesis The thesis has 130 pages and consists of chapters, including intruduction 02 pages, literature review 37 pages, research object and methods 24 pages, results 28 pages, discussion 36 pages, conclusion 02 pages, and recommendations 01 page The thesis has 39 tables, charts, and 49 figures The thesis has 152 references including 14 Vietnamese documents and 138 English documents There are 03 article relating to the thesis that have been published in the Journal of 108 - Clinical Medicine and Pharmacy Chapter LITERATURE REVIEW 1 General concepts of immediate placement 1.1.1 Concept, classification, advantages, and disadvantages of immediate placement An immediate placement (IP) is an implant placed immediately after tooth extraction, with or without bone grafting Hammerle classified according to timing of implant placement into : immediate implant placement in fresh extraction socket ; early implant placement when the soft tissue has healed; delayed implant placement when there is a new bone part; late implant placement when the socket has healed The advantages is reducing treatment time and cost; decreased need for bone augmentation, preservation of the soft tissue, improved implant positioning The disadvantages is large alveolar bone morphology, complicated surgical techniques; anatomical limitations, lack of primary closure, presence of acute and chronic pathology 1.1.2 Atraumatic tooth extraction and post-extraction alveolar bone classification The atraumatic tooth extraction is the use of a combination of dental elevators, dental forceps, the atraumatic forceps shake the teeth and an piezo surgery cut bone; peristomes cut the ligaments surrounding the tooth root before extraction Proximal reduction of the tooth and divide the root in order to minimize damage to hard and soft tissues around the extracted tooth Caplanis provided a classification of EDS (extraction defect sounding) sockets based on the number of damaged bone walls, gingival biotype, bone margin level, and gingival margin, and provided guidelines for implant treatment EDS I and EDS II can be IP Smith and Tarnow provided a classification for molars Class A and B can IP ; class C is contraindicated 1.1.3 Causes of tooth extraction in immediate placement Root fracture, crown cracks of one root-tooth due to trauma cannot be treated conservatively Complications of tooth decay cause large tooth decay under the gums, and pathology of the pulp that cannot be restored Missing permanent teeth or misplaced teeth but still have deciduous teeth Teeth with indications for extraction related to periodontitis have been treated stably and have enough alveolar bone for implant placement 1.1.4 Indications and contraindications Indications: The alveolar walls are still intact; intact facial wall with a thick phenotype; thick gingival biotype; sufficient bone volume apically of the extracted root to allow a implant positioning with good primary stability Contraindications: presence of active infection, insufficient bone beyond tooth apex, proximity to vital anatomic structures, large gingival recession 1.1.5 Implant stability Implant stability is a condition for successful osseointegration, which is a gradual replacement of primary stability with secondary stability 1.1.6 Implant characteristics IP is highly successful for implants with taper shape, rough surface, micro-threaded neck, internal abutment-implant connection and platform switching, implant length greater than 10 mm.The authors suggest using small diameter implants in IP 1.2 Mechanism of osseointegration in immediate placement 1.2.1 Dimensional changes of post-extration socket After tooth extraction, the alveolar bone has both internal and external dimensional changes, taking place through phases from blood clot formation, cleaning, bone formation, and bone remodelling Resorption is more at the buccal than lingual aspect because it is thinner and loses more bundle bone during tooth extraction 1.2.2 Morphogenesis of osseointegration in humans In humans, the process of osseointegration appears in the interval between and weeks 1.2.3 Biomechanics of immediate placement osseointegration The authors demonstrated that immediate placement osseointegration significantly faster than osteotomies by two factors Firstly, around immediate postextraction implants, gap interfaces constitute a low-strain pro-osteogenic environment Second, osteoprogenitor cells residing in the periodontal ligament that remained attached to the socket wall after tooth extraction, support peri-implant bone formation 1.3 Evaluate factors for treatment planning 1.3.1 Bone size at the implant site Cone-beam computed tomography (CBCT) has become the mandatory gold standard for determining residual bone dimensions including bone height, bone width, bone length, and bone angulation 1.3.2 tooth shape and thickness of the buccal wall The tapered teeth has more inter-proximal bone between the teeth and more facial bone over the tapered root; but soft tissue is usually thin A square tooth form has thick soft tissue but there is less bone between the roots and large horizontal defect dimension (HDD) IP does not prevent osseous resorption but it reduces resorption The cortical bone does not contain endothelial blood vessels, so complete resorption of the buccal wall can occur after tooth extraction if there is no implantation or alveolar bone preservation 1.3.3 Bone density and expected implant location Bone density often depends on arch position When teeth are lost, bone density will reduced over time Implant position in IP is determined by anatomical position Implants in the anterior maxillary region should not be placed near the buccal wall but located in the lingual wall of alveolar bone In the anterior mandibular region, the implant should be placed more towards the tongue, but not as much as in the maxillary In the posterior regions of maxillary and mandibular, the implant must be placed in the center of the extraction socket 1.3.4 Soft tissue aesthetic The patient should be evaluated preoperatively, including the smile line; form and restoration of adjacent teeth; hard and soft tissue thickness Smile line: IP in the aesthetic region should avoid patients with high smile lines Gingival type: IP can cause slight resorption whether the soft tissue is thin or thick 1.4 Positioning techniques, bone grafting, and temporary prosthesis 1.4.1 Positioning technique The directional axis of the bone drill is based on the final prosthesis Many authors have introduced new techniques: locating drill before extracting the roots With the maxillary central incisor, the socket shield technique keeping a part of the tooth root intact not only ensures aesthetics but also prevents the resorption of soft and hard tissues Today, thanks to technological developments, bone locating drills can be assisted by surgical template or assisted by implant navigation software 1.4.2 Bone grafting Bone graft has many different functions such as supporting the membrane, and acting as a scaffold for bone to grow in from the bone receiving region Bone grafts are divided into types, including Autograft, Allograft, Xenograft, and synthetic bone The barrier membrane consists of a digestible and an indigestible membrane Guide bone regeneration can be performed simultaneously with the implant placement or alone Bone growth factors enhance bone graft formation and mineralization More than 50 growth factors have been identified There are two common techniques for generating bone growth factors today: plateletrich plasma and bone morphoprotein 1.4.3 Immediate load or Staged treatment After IP, depending on the case, it is possible to install temporary prosthesis immediately, place healing abutments or in stages IP usually has low primary stability, so it is only loaded when full osseointegration IP can be restored after months of healing, but with low primary stability, with many bone grafts, restoration can be done after 4-5 months 1.5 Status of immediate implant placement research Studies in the world IP has the ability to succeed in all regions of maxillary and mandibular, the success rate is high not only for teeth in esthetic regions but also with molars from 96.1-100% Studies in Vietnam There have been many authors who have studied implant placement, in studies involving both immediate and delayed placement Achieving implant stability is a prerequisite for successful osseointegration; so many studies have evaluated the correlation between implant stability and bone density, insertion torque, and bone defect around the implant in IP However, these studies evaluated the individual, independent impact of implant stability without considering the interrelationships between factors From there, we study to evaluate the influence of concurrent factors on implant stability as well as healing time in IP Chapter RESEARCH SUBJECTS AND METHODS 2.1 Research subjects Subjects selected for the study are patients over 18 years old, who are indicated for tooth extraction and restoration with immediate implant placement at the Dental Department, 108 Military Central Hospital from September 2015 to September 2021 2.1.1 Selection criteria The patient has IP indications; be healthy enough for surgery; agrees to participate in the research After tooth extraction, alveolar bone is types EDS I and EDS II for single-rooted teeth; Class A, B for molars 2.1.2 Exclusion criteria The patient has local, systemic acute infection of the maxillofacial region; has diseases that are contraindicated for surgery; has mental illness, does not consent to participate in the research; has a history of radiotherapy to the maxillofacial region, severe osteoporosis due to bisphosphonate; is a heavy smoker, has bruxism, poor oral hygiene; has the apical bone defect is larger than the expected implant diameter 2.2 Research Methods 2.2.1 Research design Non-randomized clinical trial 2.2.2 Sample size Formula to calculate sample size: n = ⁄ ⁄ ⁄ is the confidence coefficient = 1.96 with a 95% confidence interval p: success rate according to previous research is 93.1% d: estimated error within 0.05 n: calculated sample size is 99 implants In fact, we placemented 112 implants in 85 patients 11 Step 7: Bone grafting, barrier membrane HDD < 2mm does not need bone grafting HDD ≥ mm, bone grafting with bone graft and barrier membrane Step 8: Closure with healing abutment, temporary prosthesis Step 9: Install the prosthesis Prosthesis when ISQ ≥ 65 Install screwed prosthesis including a Titanium base abutment and a multi abutment Installation of cement-fixed prosthesis (Fuji Flus) includes standard abutment, Scalloped abutment, individual abutment 2.5 The method of data collection Data were collected at the following times: preoperative; intraoperative; healing phase; when installing prosthesis (T0) and after months (T1), 12 months (T2), 24 months (T3), 36 months (T4) 2.5.1 Preoperative evaluation indicators Patient characteristics in terms of age and gender; the cause of tooth extraction; location of extracted teeth; The remaining bone size is based on the assumed implant size Bone density: based on CBCT combined with hand feeling when drilling CBCT: survey the bone in the area below the apex of the roots, not coincident with the tooth that the implant is expected to be placed in, the software will automatically display the average Hounsfield unit of that area Gingival type: divided into thick and thin gingival tissue based on the ability to see the tip of the colored periodontal probe; evaluated according to implant position Smile line: divided into categories high, medium and low 2.5.2 Intraoperative monitoring indicators Flap designs: Open (full thickness) flap, minimal flap and flapless Insertion torque: at levels 20, 25, 30, 35, 40, 45, 50, 55, 60, 65 N.cm Bone grafting Temporary Prostheses: fixed, removable and healing abutment Surgical complications: recorded during and after surgery 12 2.5.3 Indicators in the healing phase Post-surgery pain: according to the scale of VAS, divided levels Healing time: from implant placement until ISQ ≥ 65 to be able to install prosthesis Prosthetic types: crown and bridge Attached method: cement and screw 2.5.4 Follow-up indicators after restoration Implant stability: measured by resonance frequency analysis with ISQ unit We measure only before restoration ISQ ≥ 65, then prosthesis are installed, ISQ < 65, increasing healing time Expression implant failure when ISQ < 45 Pain when chewing Gingival and bleeding index: the Löe and Silness classification Modified Plaque index (mPLI): Mombelli's modified plaque index Probing depth PD (Probing depth): is measured with a pocket gauge with a slight force of the wrist brought parallel in the direction of the implant axis, until resistance is felt Values are rounded to the nearest mm mark Loosening the prosthesis on the implant: When examining, use wrist force and the tip of the dental fork to shake the prosthesis in the inner-outer direction The marginal peri-implant bone loss: assessed on digital radiographs with parallel imaging technique, specialized measurement software Method of determination: must first determine the proximal and distal bone margins around the implant on the radiograph as the distance value from the first position of bone contact with the implant surface at the proximal and distal position to the passing line implant shoulder line at time T0, T1, T2, T3, T4 The difference between the values at the time of assessment (T1, T2, T3, T4) and T0 is the degree of bone resorption at the 13 time of assessment In addition, the bone resorption rate can be calculated at a point in time by the difference between that time and the previous evaluation time To minimize dimensional distortion, measure the implant size on the digital radiograph, then divide by the actual size of the implant to get the magnification factor, then divide the bone loss measured on the digital film by magnification factor to capture the actual amount of bone lost 2.5.5 Evaluation of results after restoration Assessment of chewing function; aesthetic function: according to good, average, poor levels Success and failure rate: based on Misch's criteria to assess implant success Prosthetic complications Sample size at the time of evaluation: the sample size at any evaluation time is the number of implants evaluated at that time after wearing the prosthesis Cumulative rate: all implants were calculated at the time of final evaluation in the study 2.6 Data processing The data were collected and processed using the SPSS 20.0 statistical software 2.7 Ethics in research The research topic was approved by the proposal review committee We commit to not affecting the patient's health Patients were fully explained about the purpose, requirements, and content of the study; the advantages and disadvantages of the treatment method The patient's medical and personal information is kept confidential by us 14 Chapter RESEARCH RESULTS 3.1 clinical and radiographic characteristics of the teeth with indications for immediate placement 3.1.1 Patient characteristics Male 61.2%, female 38.8% The youngest was 18, the oldest was 76, the average is 44.1 ± 15.1 years old; over 30 years old 80 % 3.1.2 Location of extracted teeth Chart 3.1 Location of extracted teeth Number of teeth in mandibular 63.1 %; maxillary 36.9%; anterior teeth 36.0%; premolars 29.7%; molars 34.2% 3.1.3 Causes of tooth extraction Dental decay 39.6%; periodontitis 36%; Trauma 19.8%; missing teeth 4.5%; the tooth regions were significantly different (p < 0.05) 3.1.4 Remaining bone size at the extraction site according to the expected implant Implant diameter Implants have a diameter of 3.5-5.0 mm; the most are 3.5 mm implants with 32.1% The implant has a length of 8.5-13 mm; the most are 11.5 mm 15 with 50.9% The implant diameter and length between regions were significantly different (p < 0.05) 3.1.5 Aesthetic factors Thick gingival type was 78.6%: anterior teeth was 65%; premolars was 75.8%; molars was 94.9 %; the regions were significant different with p < 0.05 The total percentage of average and low smile lines was 83.5%; there was no relationship between smile lines and gender 3.1.6 Bone density D1 0.9%; D2 22.3%; D3 71.4%; D4 5.4%;, there was a difference between tooth regions (p < 0.05) 3.2 Surgery results 3.2.1 The technique of flap design Open flap 58.9 %; minimal flap 32.1 %; flapless 8.9%; there were differences between the tooth regions 3.2.2 Insertion torque Insertion torque 20-30 N.cm 12.5% ; D4 bone only reaches 20-30 N.cm The insertion torque 35-45 N.cm 67.0% There was a relationship between insertion torque and bone density 3.2.3 Bone grafting Bone grafting rate was 30.4%; there was no difference between tooth regions 3.2.4 Temporary prosthesis Fixed temporary prosthesis in the anterior teeth region with 96.8%; removable prosthesis in the anterior region with 83.3% Molars is completely placed by a 100 % healing abutment 3.2.5 Post-surgical pain Pain 97.3%, mainly moderate and mild pain 3.2.6 Prosthesis and methods of attaching prosthesis to implant Prosthesis: single crown 63.4%; bridge 36.6% Attached method: cement 67.9%; screw 32.1%; there was a difference between tooth regions (p < 0.05) 16 3.2.7 Surgical complications Swelling 9.8%; profit loss 3.6%; other cases 0.9% 3.2.8 Changes in soft and hard tissues around the implant Soft tissue condition The index of gingival and bleeding had no difference at months, 12 months, 24 months and 36 months with 0.84 ± 0.68; 0.82 ± 0.60; 0.92 ± 0.80 and 0.87 ± 0.88 The plaque index around the implant at 6, 12, 24 and 36 months, respectively, was 0.66 ± 0.35; 0.73 ± 0.41; 0.67 ± 0.40 and 0.56 ± 0.37; there is a difference between and 12 months; 12 with 24 months There were different probe depths at 6, 12, 24 and 36 months, respectively, was 3.25 ± 1.17; 2.77 ± 0.71; 2.67 ± 0.41 and 2.62 ± 0.63 mm Marginal bone loss after restoration The degree of mesial and distal bone resorption increased significantly over time The rate of bone loss from the 2nd and 3rd year was 0.21 ± 0.12 mm and 0.14 ± 0.13 mm, respectively Bone loss at times months ( 0.50 ± 0.93) and 12 months ( 0.58 ± 0.69 ) has a much larger standard deviation than the mean 3.2.9 Chewing and aesthetics function The chewing function at good at evaluation times from 85.3 to 91.9% Aesthetics function at good at evaluation times from 79.4 - 90.2% 3.2.10 Prosthetic Complications In years, there was a total of 20.5 % screw loosing; 4.5% porcelain fracture; prosthetic loose fitting 0.9%; broken abutment 0.9% 3.2.11 Results There were failed implants in months; implant failed after 12 months The cumulative success rate after years was 86.6%; peri-implant mucositis was 5.4%, early peri-implantitis was 2.7% and failure 5.4% 17 The cumulative implant survival rate after years was 94.6% (106/112) Molar failure rate was 10.3%; maxillary molar 28.6% 3.3 Determining some factors affecting the healing time and implant stability 3.1 Healing time Healing time 3-4 months 65.2%; over months only 2.7% Table 28 coefficient variables Model Unstandardized coefficient p VIF Constant 5.730 0.000 Bone graft 1.641 0.000 1.028 Insertion torque -0.056 0.000 1.028 Adjusted DurbinR square Watson 0.648 1.869 Regression equation with the level of explanation 64.8%: Healing time = 5.730 + 1.641 * Bone graft - 0.056 * Insertion torque (1) 3.3.2 Implant stability Table 32 coefficient variables Model Unstandardized coefficient p VIF Constant 64.236 0.000 Bone graft -3.184 0.000 1.028 Insertion torque 0.299 0.000 1.028 Adjusted R Durbinsquare Watson 0.451 1.759 Regression equation with the level of explanation 45.1%: ISQ = 64.236 - 3.184 * Bone graft + 0.299 * Insertion torque (2) 18 Chapter DISCUSSION 4.1 Clinical and radiographic characteristics of the teeth with indications for immediate placement 4.1.1 Patient characteristics Patient gender and age The authors agree on the selection of the age of transplant patients in general and IP in particular Do not choose the case of too young age where the organization of the extraction region has not fully developed, when implanted, it will lead to stiffness At the same time, patients who are too old should not be selected because of the high likelihood of chronic diseases, poor surgical health, limited blood supply to the transplant and bone grafting regions, and slow healing., as well as poor osseointegration leading to a high risk of failure 4.1.2 Location of extracted teeth IP can be performed in tooth regions, the ratio of tooth regions is not much different Although each tooth region has advantages and disadvantages for the IP method, because the frequency of examination and treatment of each tooth group is different, the study rate does not differ between groups of teeth 4.1.3 Causes of tooth extraction The causes of tooth extraction in IP are the same as those leading to normal tooth extraction and have their own characteristics in each tooth region 4.1.4 Remaining bone size at the extraction site according to the expected implant IP is in different regions so the implant diameter does not focus on a specific size; however, the implant length ≥ 10 mm accounts for 91%, the 11.5 mm long implant accounts for the most in each different implant diameter This is consistent with the results of Schnitman's study in IP, which showed that only the implant length ≥ 10mm ensures the primary stability ... recession 1.1.5 Implant stability Implant stability is a condition for successful osseointegration, which is a gradual replacement of primary stability with secondary stability 1.1.6 Implant characteristics... measuring dimensions - NSK implant machine, Tekka implant and surgical kit - Intra-oral minor surgery kit, colored periodontal probe - Implant stability device with ISQ (implant stability quotient) unit... method still has limitations such as the size of the alveolar bone, and the implant is often not suitable, often not achieving the desired primary stability The stability of the implant is affected