Résumé
@#The standardized workflow of computer-aided static guided implant surgery includes preoperative examination, data acquisition, guide design, guide fabrication and surgery. Errors may occur at each step, leading to irreversible cumulative effects and thus impacting the accuracy of implant placement. However, clinicians tend to focus on factors causing errors in surgical operations, ignoring the possibility of irreversible errors in nonstandard guided surgery. Based on the clinical practice of domestic experts and research progress at home and abroad, this paper summarizes the sources of errors in guided implant surgery from the perspectives of preoperative inspection, data collection, guide designing and manufacturing and describes strategies to resolve errors so as to gain expert consensus. Consensus recommendation: 1. Preoperative considerations: the appropriate implant guide type should be selected according to the patient's oral condition before surgery, and a retaining screw-assisted support guide should be selected if necessary. 2. Data acquisition should be standardized as much as possible, including beam CT and extraoral scanning. CBCT performed with the patient’s head fixed and with a small field of view is recommended. For patients with metal prostheses inside the mouth, a registration marker guide should be used, and the ambient temperature and light of the external oral scanner should be reasonably controlled. 3. Optimization of computer-aided design: it is recommended to select a handle-guided planting system and a closed metal sleeve and to register images by overlapping markers. Properly designing the retaining screws, extending the support structure of the guide plate and increasing the length of the guide section are methods to feasibly reduce the incidence of surgical errors. 4. Improving computer-aided production: it is also crucial to set the best printing parameters according to different printing technologies and to choose the most appropriate postprocessing procedures.
Résumé
@#After tooth extraction, labial contour collapses due to inevitable physiologic bone remodeling. To achieve optimal outcomes for pink esthetic treatment at anterior implant sites, bone or soft tissue augmentation has been advocated to maintain or reconstruct the labial tissue contour. When choosing soft tissue augmentation for esthetic restoration, it is necessary to strictly grasp the indications for surgery. Soft tissue augmentation to maintain or reconstruct the labial tissue contour could be considered in patients with healthy soft tissue and no bone defects or only mild horizontal bone defects. In immediate, early and late implant placement, the timing of soft tissue augmentation may vary. In immediate implantation, the labial bone plate is intact, so it is highly recommended to simultaneously manage soft tissue during implant placement. However, patients may have large bone defects with early or late implant placement. The risk of augmenting bone and soft tissue simultaneously is likely too high, and bone augmentation surgery is often performed at the first stage while soft tissue augmentation surgery is performed at the second stage. Therefore, soft tissue surgery is often carried out simultaneously with abutment connection. Currently, soft tissue augmentation is achieved mostly with adjacent autologous soft tissue grafts, such as free gingival grafts, subepithelial connective tissue grafts or pedicle palatal flaps, which are often accompanied by a second surgical area. The replacement of autogenous soft tissue grafting with new biological materials will become an inevitable trend. In this article, we analyze and summarize the indications, timing and different methods of soft tissue augmentation to maintain and reconstruct the labial contour.
Résumé
@#The rapid absorption of labial alveolar bone after tooth extraction not only reduces the aesthetic effect of implant repair but also affects the long-term success rate of implants. The socket shield technique is reported as the latest alveolar preservation technique in the aesthetic zone from both domestic and international case reports and shows a high success rate of short-term osseointegration and excellent aesthetic effects. However, some investigations have shown short- and long-term complications with the socket shield technique, such as failure of osseointegration, loss of crestal bone and buccal bone, inflammation, etc. In this review, the socket shield technique will be reported in detail with its pros and cons. Although the socket shield technique has achieved good clinical effects and short-term success rates in many cases, there are still no conclusions regarding the surgical procedure, such as the thickness, the position of the shield, whether to put the graft material between the shield and implant, etc. Due to the lack of long-term research or a large amount of clinical literature support and technical sensitivity, the socket shield technique should be carefully used in clinical application to reduce unexpected risks.
Résumé
Objective@#To explore the effect of RW splints on the position and occlusal relationship of classⅡ malocclusion patients with temporomandibular disorder (TMD) to provide a basis for the diagnosis and design of this kind of patient. @*Methods @#Fifteen patients with class Ⅱ malocclusions with TMD were enrolled in this study. After 8 months of RW-splint treatment, the changes in jaw position (∠ANB, SN-MP, ∠S-G0/N-Me) and occlusal relationship (molar, cuspid teeth displacement and anterior overbite/overjet value) were recorded by a condylar displacement measuring instrument at the CR position and CO position.@*Results@#After RW-splint treatment, the mean values of ∠ANB (t=4.971, P=0.001) and ∠SN-MP (t=9.895, P ＜ 0.01) were increased in all 15 patients, and the mean value of S-G0/N-Me (t=5.342, P=0.005) was decreased. The mean values of the distal movement of the first molars on the left and right sides of the mandible were (1.57 ± 0.79) mm and (1.69 ± 1.29) mm, respectively; the mean values of the distal movement of the canines on the left and right sides of the mandible were (1.54 ± 0.50) mm and (1.51 ± 1.08) mm, respectively; and the mean values of the overbite were (1.16 ± 0.60) mm and (1.99 ± 0.85) mm, respectively. @*Conclusion@# After RW-splint treatment, the jaw rotates clockwise, and the relationship between the molars and canines changes obviously in class Ⅱ patients with TMD, which provides a reference for the diagnosis and treatment plan of this kind of patient.
Résumé
Objective@#To evaluate the clinical effect of a digital whole-process surgical guide for immediate implantation in the molar area. @*Methods @#Twenty-six patients with molar extraction plans were accepted for preoperative CBCT and model construction. Computer software was used to design the ideal three-dimensional position of the implant. The control group of 13 patients underwent immediate implantation with a free hand operation, whereas the experimental group of 13 patients underwent preparation and implant insertion under the guidance of a surgical guide. Bone grafting was performed, and a good initial stability was achieved. After 5 to 6 months, osseointegration was achieved, and the final restoration was delivered. After surgery, the accuracy of the three-dimensional position of the implants was measured, and at the 6 month return visit, the modified Plaque Index (mPLI), modified Sulcular Bleeding Index (mSBI) and probing depth (PD) were measured. @*Results @# In the control group and experimental group, the vertical errors at the top of the implants were 1.246 ± 0.072 mm and 0.628 ± 0.046 mm (t = 26.078, P < 0.001), respectively, and the horizontal errors were 1.563 ± 0.086 mm and 0.546 ± 0.056 mm (t = 35.813, P < 0.001), respectively; and the vertical errors at the root of the implants were 1.352 ± 0.042 mm and 0.532 ± 0.030 mm (t = 57.021, P < 0.001), respectively, and the horizontal errors were 1.645 ± 0.076 mm and 0.625 ± 0.072 mm (t = 35.086, P < 0.001), respectively. For the experimental group, the mPLI value was 0.923 ± 0.760, the mSBI value was 0.846 ± 0.689, and the PD value was 3.460 ± 0.713 mm, which were significantly lower than those of the control group. For the control group, the mPLI value was 1.769 ± 0.927 (t = 2.546, P = 0.018), the mSBI value was 1.692 ± 0.947 (t = 22.605, P = 0.016) and the PD value was (4.579 ± 0.475) mm (t = 4.709, P < 0.001). @*Conclusion@#A digital surgical guide plate can increase the precision of immediate implantation and the peri-implant health in the molar area.
Résumé
OBJECTIVE@#This study aimed to evaluate the clinical effect of periodontal microscopic surgery on the augmentation of attached gingiva and determined the clinical principle on how to use minimally invasive surgery to improve the surgery success rate.@*METHODS@#Twenty patients with insufficient attached gingiva around implants were selected. Periodontal microscopic surgery for free gingival graft was performed to increase the width of the attached gingiva around the implants. The survival state of the free gingiva was observed after surgery, and the width of the attached gingiva around the implants was recorded before and after surgery and 1 year after surgery. The shrinkage rate of the free gingival flap 1 year after surgery was analyzed to evaluate the stability of the flap.@*RESULTS@#The flaps of the 20 cases all survived. One year after the operation, the width of the attached gingiva was (3.05±0.44) mm, which increased compared with that of preoperation (2.56±0.31) mm and decreased compared with that of postoperative day (2.13±0.28) mm. The shrinkage rate of the attached gingiva was 41.22%±5.04%.@*CONCLUSIONS@#The application of microscopic surgery on the augmentation surgery of attached gingiva can increase the success rate and improve the quality and quantity of attached gingiva around implants.