Positioning Of Dental Implants Research Articles

The effectiveness of dental implantation in patients with type II diabetes mellitus

The issue of the safety of dental implants in patients with diabetes mellitus, despite the increase in the number of orthopedic corrections of partial or complete adentia with their use, remains open [1].
 In such a situation, the most urgent question is the development of new, safe and less traumatic methods of dental implantation, which would expand the indications for prosthetics on implants for this category of persons and improve the quality of life of such patients through full-fledged correction of chewing function.
 The purpose of the study was to investigate the effectiveness and safety of the method of orthopedic rehabilitation proposed by the authors using implants in patients with type II diabetes mellitus.
 Material and methods. As part of the study, 68 patients were treated, who were divided into three groups: the main group (patients with DM operated without the formation of muco-periosteal flaps according to the protocol developed by us) — 34 patients (50 %); control group 1 (patients with DM operated according to the traditional protocol with the formation of muco-periosteal flaps) — 16 patients (24 %); control group 2 patients without diabetes, operated without formation of muco-periosteal flaps according to the protocol developed by us) — 18 patients (26 %).
 The effectiveness of dental implantation was evaluated after 2 years. Such indicators as the survival rate of dental implants and the level of bone resorption (according to the results of intraoral radiography were used as criteria. In addition, bone density was studied on the Hounsfield scale (HU).
 Results. It was found that in patients of the main group and control group 2, survival rates were 98.70 % and 98.72 %, respectively, in patients of control group 1, the survival rate of dental implants was 89.48 %, which is also comparable with literature data on dental implantation in patients with diabetes mellitus [2, 8, 9]. Possibly greater effectiveness in the main group and control group 2 is associated with a new method of dental implantation (RF Patent No. 2794843 dated 25.04.2023) [7] and the use of a collapsible navigational surgical template (Patent RU No. 2796749 dated 29.05.2023) [6], which allowed the main group and the control group to fix individual trajectories of articulation of the mandible (which further allowed to avoid incorrect orthopedic rehabilitation, which could lead to uneven or excessive load on dental implants), to avoid reduction of the alveolar ridge, to plan in advance the exact position of dental implants, and also eliminated the need for the formation of muco-periosteal flaps and further suturing.
 Conclusion. The use of the technique developed by us (RF patent No. 2794843 dated 25.04.2023) allows us to increase the effectiveness of treatment of patients with type II diabetes mellitus and bring it closer to the results of practically healthy people (according to retrospective observation for two years).

Assessment of the Anterior Loop and Pattern of Entry of Mental Nerve Into the Mental Foramen: A Radiographic Study of Panoramic Images.

The precise location of the mental foramina is an essential landmark in planning the position of dental implants in the anterior mandible. Injury to inferior alveolar nerve during anterior mandibular implant surgery causes altered sensation which greatly affects patient satisfaction. In this study, we assessed the prevalence of anterior loop of mental nerve and the pattern of entry of mental nerve into the mental foramen. Three hundred panoramic radiographs (600 hemimandibles) obtained from records maintained in the Department of Oral Medicine and Radiology were randomly selected for the study. The radiographs were evaluated by two independent observers for the pattern of entry of mental nerve into the mental foramen on either side of the mandible and for the presence or absence of anterior loop of mental nerve. The most prevalent pattern of mental nerve observed was Straight pattern which totals to 67.5% followed by Anterior loop pattern (18.8%) and then the Perpendicular pattern (13.7%). There was no significant association between the gender and subtypes of looping pattern on the left and right side and a highly significant association between the side of the mandible and loop pattern was observed by Chi square test. The Anterior loop pattern of mental nerve has been found in 18.8% of the population suggesting to accurate planning with three-dimensional imaging techniques to avoid injury to mental nerve during dental implant placement and other surgical procedure involving the interforaminal region of the mandible.

Accuracy, scanning time, and patient satisfaction of stereophotogrammetry systems for acquiring 3D dental implant positions: A systematic review.

To evaluate accuracy, scanning time, and patient satisfaction of photogrammetry (PG) systems for recording the 3D position of dental implants. A literature search was completed in five databases: PubMed/Medline, Scopus, Embase, World of Science, and Cochrane. A manual search was also conducted. Studies reporting the use of commercially available PG systems were included. Two investigators evaluated the studies independently by applying the Joanna Briggs Institute critical appraisal. A third examiner was consulted to resolve any lack of consensus. A total of 14 articles were included: 3 in vivo, 6 in vitro, and 6 case report manuscripts. One clinical study evaluated trueness, another one tested precision, and the third one assessed impression time and patient and operator satisfaction. All the in vitro studies evaluated the trueness and precision of a PG system. Additionally, all the reviewed studies investigated completely edentulous conditions with multiple implants. The number of placed implants per arch among the reviewed clinical studies varied from 4 to 8 implants, while the number of implants placed on the reference casts included 4, 5, 6, or 8 implants. Not all the studies compared the accuracy of PG systems with conventional impression methods, using intraoral scanners as additional experimental groups. For the PIC system, trueness ranged from 10 to 49μm and precision ranged from 5 to 65μm. For the iCam4D system, trueness ranged from 24 to 77μm and the precision value ranged from 2 to 203μm. PG systems may provide a reliable alternative for acquiring the 3D position of dental implants. However, this conclusion should be interpreted carefully, as one study reported a mean precision value of one PG system higher than the clinically acceptable discrepancy. Lower scanning time and higher patient and operator satisfaction have been reported when compared with conventional techniques. Further studies are needed to increase the evidence regarding the accuracy, scanning time, and patient and operator satisfaction of the commercially available PG systems.

Dental implants in growing patients: A systematic review and meta-analysis.

Dental implants provide a suitable and reliable treatment for the replacement of missing teeth. Very few studies have been reported in the literature regarding the application of dental implants in growing and developing patients. This systematic review with meta-analysis aimed to systematically review the available literature regarding the application of dental implants in growing and developing patients. A detailed search in the literature was performed with the help of keywords such as dental implants, treatment planning, children, adolescents, growing patients, and developing jaws. PubMed, Scopus, Web of Sciences, and Ovidsp databases were searched for papers published between 1980 and 2021. The papers focused on children, adolescents, developing jaws, and implants. In this systemic review, the dataset concerned with the type of study, aim, number of patients and specimens included, age of patients, total number of implants placed, total number of implants evaluated, medical history of developmental disorders of teeth such as ectodermal dysplasia, congenital absence of teeth, were evaluated. Out of the total literature searched, 33.45% of studies and case reports documented no complications in any implant treatment. In 47.21% of studies and case reports, there was both success and failure of implants while in 13.21% of studies and case reports there was a complete failure of implants. The most common cause for loss of permanent teeth in growing children and adolescent patients was dental trauma (73.13%) followed by congenital developmental disturbance of teeth (18.19%). It can be concluded from this systematic review that the use of implants in edentulous growing patients is determined by several parameters, including the patient's overall health, the stage of jaw growth, the number of teeth to be replaced, and soft and hard tissue anatomic features. Still, the use of a conservative treatment strategy for missing teeth management in patients with developing jaws is common and recommended until the patient's growth is completed, as there are chances of changes in the position of dental implants placed in the developing and growing jaws due to the continuous changes taking place in their body. However, placement of implants can be done in these patients successfully with proper treatment planning and taking into account the phase of growth with proper follow-up.

Superimposition of intraoral scans of an edentulous arch with implants and implant-supported provisional restoration, implementing a novel implant prosthetic scan body.

Purpose To describe a technique utilizing a novel prosthetic scan body, that assists the accurate merging of multiple scans (intra- and extraoral) of the interim prosthesis and edentulous arch with dental implants, during rehabilitation with a fixed implant-supported prosthesis.Methods Intraoral scanning (Trios 3, 3Shape) of an interim implant-supported prosthesis was performed, subsequently followed by another scan, using five scan bodies, placed onto the implant abutments (SRA, Bone level, Straumann AG). Successively, the newly designed prosthetic scan bodies were attached to the abutment copings of the interim prosthesis, for extraoral scanning. Utilizing an implant library designed for the prosthetic scan body, the three scans were merged, providing all the necessary information for the digital design and fabrication of the fixed implant-supported prosthesis.Conclusions The described clinical technique enabled effective and accurate superimposition of intra- and extraoral scans of the implant prosthesis. Superimposed data, including that of the position of dental implants and anatomy of soft tissue, provided essential information for the fabrication of a definitive implant-supported prosthesis. The novel prosthetic scan bodies attached to the implant prosthesis, assisted in merging intra- and extraoral scans, thus facilitating the rehabilitation of maxillary and/or mandibular edentulous dental arches. Further research is required to assess the accuracy of the proposed technique.

A Custom Manipulator for Dental Implantation Through Model-Based Design

This paper presents a Model-Based Design (MBD) approach for the design and control of a customized manipulator intended for drilling and positioning of dental implants accurately with minimal human intervention. While performing an intra-oral surgery for a prolonged duration within a limited oral cavity, the tremor of dentist's hand is inevitable. As a result, wielding the drilling tool and inserting the dental implants safely in accurate position and orientation is highly challenging even for experienced dentists. Therefore, we introduce a customized manipulator that is designed ergonomically by taking in to account the dental chair specifications and anthropomorphic data such that it can be readily mounted onto the existing dental chair. The manipulator can be used to drill holes for dental inserts and position them with improved accuracy and safety. Furthermore, a thorough multi-body motion analysis of the manipulator was carried out by creating a virtual prototype of the manipulator and simulating its controlled movements in various scenarios. The overall design was prepared and validated in simulation using Solid works, MATLAB and Simulink through Model Based Design (MBD) approach. The motion simulation results indicate that the manipulator could be built as a prototype readily.

Is Intraoral Scanning Accurate to Evaluate Dental Implant Position? An In-Vitro Study

The position of dental implants is generally verified through imaging exams, even though its use exposes patients to radiation. Intraoral scanning (IOS) may be a suitable alternative to using radiographic imaging to verify implant position. Using polyurethane jaw models, the purpose of this in-vitro study was to measure and compare implant positions determined by IOS and cone-bean computed tomography (CBCT). One hundred twenty implants were installed in 30 edentulous polyurethane jaws, 4 dental implants in each prototype. Four scanbodies were attached to the implants, and a scanning of each mandible was acquired using an intraoral scanner (CS 3600). All prototypes were also submitted to CBCT. Then, the 3D scan files in STL (Standard Tessellation Language) format were superimposed on the DICOM (Digital Imaging and Communications in Medicine) images of the tomographic mandibles. The accuracy of IOS was evaluated by the metric analyses of deviations between the position of the implants projected by the IOS versus the detected tomographically, in which CBCT served as the gold standard, using a free software for digital planning (Bluesky 4 - Grayslake, IL, USA). The following measures were analyzed: radial deviations at the shoulder (Xc) and at the apex of the implants (Xa), height deviation (Xh) and axial deviation. Bland-Altman and a paired t-test were applied to verify the reproducibility between measurements and a t-test for a mean was applied to compare the measurements with zero value. The results showed Xc and Xa deviation means of 0.14±0.09mm and 0.12±0.12mm, respectively. The Xh mean was 0.2±0.12mm and the axial deviation mean was 0.71°±0.66°. T-test showed a statistically significant difference when the 4 means were compared to zero value, represented by the CBCT (P<.0001). There was a statistically significant difference IN the scanned measures compared to CBCT as the standard, but the differences may not be clinically significant. The IOS utilization to evaluate the position of dental implants is a radiation-free and reproducible method, with the advantage of not generating metal artifacts. Further clinical studies are needed to validate this new method of postoperative evaluation.

Surgical management of deficient alveolar ridges by means of guided bone regeneration in oral implantology

Dimensional changes in the alveolar ridge after extraction often compromises on achieving optimal implant stability and placement of implants in the right prosthodontic positions. These situations demand augmentation of the residual ridge to achieve successful implant placement and long-term survival. A minimum amount of bone width and height is essential for the successful placement of implants. Unfavourable local conditions, due to atrophy, trauma and periodontal disease, may provide insufficient bone volume or an unfavourable interarch relationship, which does not allow correct and a prosthodontically guided positioning of dental implants. Guided bone regeneration, ridge splitting, block graft, or distraction osteogenesis have all been applied for this purpose and have shown some promising results. Nonetheless, autogenous block graft remains one of the main methods for reconstructing severely resorbed maxilla. These block grafts can be harvested from intraoral or extraoral sites. Significant amounts of autogenous bone can be procured from symphysis or ramus region of the mandible. The cortical grafts of this area provide predictable increase in bone volume with a short healing time and yield a highly dense osseous architecture for implant placement.This review discusses the use of autogenous block grafts and bovine bone allograft for predictable bone augmentation in atrophic ridges.

Digital Planning Technique for Surgical Guides for Prosthetic Implants before Orthodontic Treatment

Background: The use of digitalization allows clinicians to plan the position of dental implants in orthodontic patients treated with aligners in the beginning of their orthodontic treatment, instead of waiting until the end of orthodontic treatment, integrating implant restorations with orthodontic biomechanics. Aim: The aim of this case report is to describe a digital workflow for aligner treatment supported by implants, in which implants are placed at the beginning of the treatment and support the orthodontic treatment. Materials and Methods: Digital planning for orthodontic treatment with clear aligners and the preparation of surgical guides for implant surgery before orthodontic treatment are used to solve two multidisciplinary cases. Cone-beam computed tomography (CBCT) and virtual dental impressions are used for the virtual planning. Successively, a surgical guide for implant placement and aligners are used in the treatment plan. Results: The digital orthodontic setup with the integration of the root position allows the clinician to plan the position of dental implants on the final occlusion. The placement of the implant before the start of the orthodontic treatment allows the implants to be used as skeletal anchorage, thereby helping the orthodontic biomechanics. Conclusions: This study describes how to perform a digital workflow with orthodontic virtual planning and the design of surgical guides for implant placement. This technique is potentially promising for complex orthodontic cases.

Implant guides

In spite of significant developments in technologies and techniques, the correct positioning of dental implants remains an arduous task. Diagnostic casts and orthopantomogram do not provide the three-dimensional radiographic information essential for proper placing and orientation of the dental implant, which might lead to unforeseen results. Prosthetically guided implantology became the need for successful outcomes. In this concept, the ideal placement of an implant is determined by the final restoration and its correlation with adjoining structures. Three-dimensional radiography, considered to be the gold standard in implant planning in terms of accuracy, fails in meeting its objectives unless the data acquired are transferred with any guide or template. Various designs and sorts of implant guides have been described, ranging from basic designs that just indicate the appropriate implant site to extremely complicated designs that, while requiring a significant amount of time and money, guide the entire surgical procedure. This review article seeks to discuss the recent advancements in implant guides.

Guided surgery in implantprosthetic rehabilitation

The prosthetic result as well as the long– term success in implant–prosthetic rehabilitation depends on a series of factors such as: position, number of implants, surgical technique, bone and mucosal offer, and others. Usually, free hand surgery does not allow in all the cases to place implants in best position from the prosthetic and biomechanical point of view. Due to the development of scanning technologies and three–dimensional printing, the planning of final results allows the printing of surgical guides, to ensure the most accurate position of dental implants [1,2]. The comparative analysis of conventional and guided implant placement methods has demonstrated significant advantages in favor of guided surgery. However, with the application of additional maneuvers in the treatment (impression, scanning, planning, template fabrication), a number of disadvantages and errors were observed that may affect both, the treatment and results.

Mandibular reconstruction using a new design for a patient-specific plate to support a fibular free flap and avoid double-barrel technique.

SUMMARYMandibular reconstruction is a primary concern for head and neck reconstructive surgeons because of the aesthetic restoration needs after ablative surgery, as well as for functional reasons: the mandible has a central functional role in speaking, swallowing and mastication. It is generally agreed that the gold standard for mandibular reconstruction is a bone free flap supported by a reconstructive titanium plate. The fibular flap represents the first choice for multi-segment mandibular reconstruction. The fibula, harvested as a single barrel graft, does not exhibit sufficient thickness to reach the original height of the native mandible; therefore, the positioning of dental implants is often deeper than that of the native alveolar crest. The aim of this study was to evaluate the positioning of the fibular free flap as it pertains to the restoration of vertical mandible height, by modifying the design of a 3D-printed titanium patient-specific implant (PSI). In this novel reconstructive workflow, the customised plate was projected to support the fibular flap at an alveolar bone position above the typical inferior mandibular border, and carried out on four patients. All patients were treated for benign neoplasms involving mandibular bone. Clinical outcomes and accuracy of the procedure are described. Our reconstructive proposal appears to be a valid alternative to the double-barrel technique in order to restore the vertical height of the reconstructed mandible.

A multifunctional guided surgery to assist in the 3-dimensional positioning of dental implants and in obtaining a palatal gingival graft

Parameters such as the correct 3-dimensional positioning and the quality of peri-implant soft tissues are fundamental to the success of implant-supported restorations. Digital planning and guided surgery techniques can make the implant placement more accurate, and modifying the periodontal phenotype is often fundamental to increasing esthetics and peri-implant health, mainly in esthetic areas. This article describes a guided surgery technique that assists in the 3-dimensional positioning of implants and identifies the best anatomic area (volume and safety) for obtaining a palatal gingival graft.

Digital Systems in Medical Science and Modern Dentistry

Digital expert systems, commonly used in medicine, can be implemented successfully in the analysis and planning of treatments in dentistry. In implant-prosthetic therapy, these software applications epresent necessary adjuvant tools in optimizing therapeutic decisions regarding the pro-implant and implant stages as well as in creating a therapeutic planning algorithm. PRODENT Acad Expert (data recording and database) and PRODENT Indices (calculation of biological indices and recommendation for the optimal treatment solution) (Neo-Tech, Romania) are tools that allows the registration and entry of data in the database, registration of clinical and biological indices in pretreatment and post-implant stage, respectively the recommendation of an optimal prosthetic solution. The use of this application is necessary in monitoring changes related to the biological components of the stomatognathic system in postimplant stage. Expert applications for the assessment of mucosal and bone support, planning of bone addition procedures and positioning of dental implants laid the foundations of digital implantology (Implant 3D, Universe; NobleGuide, Nobel Biocare; Digital Smile Design, DSD; SimPlant, Dental Materialize; Virtual Implant Placement, BioHorizons; ImplantMaster, iDent; Implant 3D, Media Lab; EasyGuide, Keystone Dental). The Digital Smile Design favors the planning of prosthetic therapy and the design of the future prosthetic work in accordance with the aesthetic principles and the requirements of the patients, based on a motivational mock-up. Literature data demonstrate the increase in the long-term success rate in digital-assisted implant-prosthetic therapy and justify the widespread expansion of the use of digital applications in current contemporary dental practice.

Treatment of extensive tumors of the jaws by hemimandibuloectomy with simultaniouse reconstruction of the mandible, arthroplasty of temporomandibular joint, orthopedic rehabilitation supported by dental implants

Background. Reconstruction of subtotal and total defects of maxillofacial region after ablative tumor surgery is a challenging task of reconstructive surgery. The “golden rule” is maintaining of radicalism of ablative surgery as well as appropriate surgical reconstruction and prosthodontic rehabilitation, that allows patient return to normal life. Wherein reconstructive procedure is focusing on restoring of mandibular continuity by the means of different flaps and grafts, while prosthodontic rehabilitation is performing after some period of time (usually around year) by the means of removable and non-removable prosthodontic devices. Non-removable device requiring dental implants insertion into grafted material followed by period of osteointegration, that is requiring some time as well. However, within this period of time one could observe significant soft tissue deformity.The objective is to improve the outcomes of surgical reconstruction of extensive defects of the mandible and to carry out rapid prosthodontic rehabilitation supported by dental implants by application of 3D preoperative planning and navigation devices.Clinical case. Forty-nine years-old female patient with recurrent ameloblastoma, that affects vertical and horizontal ramus of the mandible. Within virtual preoperative planning one performed: resection of the mandible associated with exarticulation of condylar head, virtual plate bending according to contours of the mandible (that were determined by application of “mirror” function of virtual planning software), arthroplasty of temporomandibular joint, determination of donor site on fibula bone, osteotomy of fibula free flap, positioning of dental implants, transferring of composite flap and it’s fixation by reconstructive plate. According to acquiring data one performed fabrication of patient specific navigation guides for both fibula flap segmentation and dental implants positioning. Surgical procedure included single-step tumor ablation and exarticulation of condylar head, reconstruction of defect by the means of osseo-myo-cutaneous fibula free flap, that was pre-implanted by dental implants, total joint reconstruction by titanium condylar head and polypropylene fossa, fixation of the flap and condylar head in recipient site by the means of prebended reconstructive plate, as well as insertion of non-removable bridge prosthodontic device. Postoperative result was asses clinically and radiologically. No significant postoperative complications occurred. Restoration of facial contours, mouth opening, I class occlusion, as well as adequate meal and speech were detected. Postoperative radiological investigation revealed adequate positioning of dental implants within neo-mandible, as well as positioning of artificial joint.Conclusion. In cases of extensive tumors of the jaws single-step ablative surgical procedure, reconstruction of missing anatomical structures of the jaws and simultaneous prosthodontic rehabilitation allows to prevent possible deformities of the soft tissues and due to rapid restoration of vital functions has great impact to quality of patient’s life. Adequacy of performing procedures could be reached by implementation of virtual preoperative planning and fabrication of patient-specific surgical guides.

Prosthetic resolution of malpositioned dental implants with 5-year follow-up

The poor positioning of dental implants directly influences the functional and esthetic result of the implant-supported prosthesis. And as an alternative to correcting the positioning, prosthetic components such as prefabricated and customized abutments may be used. The current study aims to present an alternative resolution for malpositioned dental implants, with the hopes of minimizing damage to osseointegration and gingival tissues. A 53-year-old female patient had two implants in regions 11 and 21 with a height discrepancy of approximately 7 mm between them. The following treatment plan was proposed: the manufacture of two metal-free crowns and the use of a customized abutment to correct the height of the implant. A metal UCLA (Universal Long Castable Abutment) was used as a healer. The case includes 5 years of follow-up. It can be concluded that the use of a customized abutment as a prosthetic solution for an implant installed far below the cervical region of the tooth presented satisfactory esthetic and functional results with peri-implant bone maintenance and long-term gingival health.Descriptors: Dental Implantation; Dental Prosthesis, Esthetics, Dental.ReferênciasGoodacre CJ, Bernal G, Rungcharassaeng K, Kan JY. Clinical complications with implants and implant prostheses. J Prosthet Dent. 2003;90(2):121-32.Branemark PI, Hansson BO, Adell R, Breine U, Lindström J, Hallén O, et al. Osseointegrated implants in the treatment of the edentulous jaw. Experience from a 10-year period. Scand J Plast Reconstr Surg Suppl. 1977;16:1-132.Simensen AN, Bøe OE, Berg E, Leknes KN. Patient knowledge and expectations prior to receiving implant-supported restorations. Int J Oral Maxillofac Implants. 2015;30(1):41-7.Hyland R, Ellis J, Thomason M, El-Feky A, Moynihan P. A qualitative study on patient perspectives of how conventional and implant-supported dentures affect eating. J Dent. 2009;37(9):718-23.Arunyanak SP, Pollini A, Ntounis A, Morton D. Clinician assessments and patient perspectives of single-tooth implant restorations in the esthetic zone of the maxilla: A systematic review. J Prosthet Dent. 2017;118(1):10-17. Higginbottom FL. Implants as an option in the esthetic zone. J Oral Maxillofac Surg. 2005; 63(9 Suppl 2):33-44.Moráguez OD, Vailati F, Belser UC. Malpositioned implants in the anterior maxilla: a novel restorative approach to reestablish peri-implant tissue health and acceptable esthetics. Part II: Case report and discussion. Int J Esthet Dent. 2015;10(4):522-32.Pelekanos S, Pozi di G, Kourtis S. Restoration of divergent implants with a 2-piece screw-retained fixed, complete dental implant prostheses. J Prosthet Dent. 2016;115(4):389-92.DeFuria C, Weber HP, Kudara Y, Papaspyridakos P. Management of a Malpositioned Implant in the Anterior Maxilla. Compend Contin Educ Dent. 2017;38(3):e9-e12.Scutellà F, Weinstein T, Lazzara R, Testori T. Buccolingual implant position and vertical abutment finish line geometry: two strictly related factors that may influence the implant esthetic outcome. Implant Dent. 2015;24(3):343-8.Funato A, Salama MA, Ishikawa T, Garber DA, Salama H. Timing, positioning, and sequential staging in esthetic implant therapy: a four-dimensional perspective. Int J Periodontics Restorative Dent. 2007;27(4):313-23.Pjetursson BE, Asgeirsson AG, Zwahlen M, Sailer I. Improvements in implant dentistry over the last decade: comparison of survival and complication rates in older and newer publications. Int J Oral Maxillofac Implants. 2014;29 Suppl:308-24.Fuentealba R, Jofré J. Esthetic failure in implant dentistry. Dent Clin North Am. 2015;59(1):227-46.Kim DG, Elias KL, Jeong YH, Kwon HJ, Clements M, Brantley WA, et al. Differences between buccal and lingual bone quality and quantity of peri-implant regions. J Mech Behav Biomed Mater. 2016;60:48-55.Arai K, Takeda Y, Mori Y, Terauchi R, Furumori T, Tanaka S, et al. Analysis of factors associated with maintenance discontinuation in implant patients. Springerplus. 2015;12;4:767.

Guided surgery in dental implantology

Dental implant surgery requires precise planning due to various anatomic limitations and restorative goals. The greatest challenges in the surgical and the prosthetic stages of dental implant surgery are due to diagnostic failure and poor case planning. With the advent of new technology surgical guides and templates can be fabricated which has made it possible to achieve more reliable agreement between the planned and final position of dental implants. These templates fabricated by sophisticated data acquisition methods and virtual planning software, seat directly on bone. They are preprogrammed with the individual depth and angulation during 3D computer simulation. It has improved preoperative planning reducing the surgical morbidity. This article reviews the concept of virtual planning and procedure of stereolithography for fabrication of surgical templates during implant planning and placement. Keywords: Dental implant, Guided implant surgery, Surgical guide, Rapid prototyping technology, Stereolithographic template, Radiographic template.

Features of dental implants’ positioning

Relevance. According to WHO, the absence of teeth occurs in various regions of the globe in 75 % of the population [1]. In the Russian Federation, tooth extraction in 35–44 years is 5.50 %, in patients older than 44 years is 17.29 % of the total number of people applying for dental treatment. Purpose. To analyze the theoretical basis for the positioning of dental implants. Materials and methods. The authors of the article carried out a retrospective analysis of the literature data on the theoretical basis for the positioning of dental implants. It was revealed that modern implantology successfully solves many problems of rehabilitation of patients with dentition defects. The conclusion. Improper positioning of dental implants entails a number of surgical and orthopedic problems, leading to disruption of the osteointegration of dental implants and, consequently, the inability of the dental implant to function.

Techniques for dental implants positioning

The modern techniques for dental implants positioning are analyzed. It is established that the duration of dental implants functioning depends on the accuracy of their positioning. The peculiarities of the influence of the human factor on the results of the installation of dental implants are revealed. It is shown that the «free hand» technique is the most inaccurate method. The accuracy of mechanical devices leaves an imprint on the results of dental implantation. Overall, the improvement of implant positioning techniques went along the way of eliminating the negative influence of the human factor on the results of the operation. For this purpose, a few mechanical devices and methods were proposed to approximate the result of the operation to the preoperative plan. Thus, the development of methods for positioning dental implants has gone from the«free hand» technique to robotic systems. Dental navigation platforms evolved along the path of improving the design and increasing the accuracy of implant positioning. In recent years there has been a sharp slowdown in the development of dental navigation systems and an increasing number of applications of robotic systems for the installation of dental implants. At the same time, the role of the implantologist gradually fades into the background, giving way to the dominant role for robotic systems that exceed the accuracy of the positioning of dental implants. In general, the use of mechanical and robotic devices in dental implantation makes it possible to achieve the best result in comparison with the «free hand» technique.

Evaluation of the 3D Augmented Reality-Guided Intraoperative Positioning of Dental Implants in Edentulous Mandibular Models.

This research aimed to propose a three-dimensional (3D) augmented reality navigation method with point cloud-based image-patient registration that could merge virtual images in the real environment for dental implants using a 3D image overlay and to evaluate its feasibility. A total of 12 rapid prototyping mandibular models were fabricated using a 3D printing method and were divided into two groups: 3D augmented reality-guided group and traditional two-dimensional (2D) image-guided group. A point cloud-based preoperative image-to-patient registration method was introduced to replace the traditional point-to-point registration. After the registration, dental implant surgery was performed in the two model groups using an augmented reality-guided navigation method and a traditional two-dimensional image-guided navigation method. The planned and actual postoperative implant positions were compared for measuring positional implantation errors. The surgery time was also recorded and compared between the two groups. In the model experiment, the root-mean-square deviation of registration was 0.54 mm, and the implant surgery results showed < 1.5-mm mean linear deviation and < 5.5-degree angular deviation. The augmented reality-guided implantation showed smaller horizontal, vertical, and angular errors in the apical areas of the central incisor and the canine region. The surgery time using the augmented reality-guided navigation method was significantly shorter than that using the two-dimensional (2D) image-guided navigation method (P < .05). Moreover, the volunteer experiment demonstrated that the preoperative 3D models in situ accurately overlaid onto the surgical site. The proposed point cloud-based registration method can achieve excellent registration accuracy. Dental implant placement guided by the proposed 3D augmented reality navigation method showed better accuracy and applicability, as well as higher efficiency, than the traditional 2D image navigation method.