3D-printed Surgical Guides Research Articles

Improving Successful Cannulation of External Ventricular Drain: 3D-Printed Surgical Guide for Inexperienced Neurosurgeons

ObjectiveExternal Ventricular Drain (EVD) is a fundamental neurosurgical procedure that is commonly performed by junior neurosurgeons. Expedient, successful cannulation of the ventricles can be lifesaving. Yet, the free-hand technique of EVD insertion is associated with significant mal-positioning rates. This study aims to improve EVD placement by junior neurosurgeons with the aid of a customized 3D printed surgical guide. MethodsA 3D printed surgical guide was developed and customized to our institution’s EVD insertion procedure. First year neurosurgical residents were taught how to perform pre-operative trajectory planning based on coronal brain images and how to use the surgical guide during standard EVD insertion procedure. Number of passes, accuracy of EVD placement, operative complications, need for revision, and surgeon’s experience with the guide were recorded. Results14 patients underwent guide-assisted EVD insertion by first year neurosurgical residents. Significantly, 6 (43%) patients had ventricular anatomy distorted by midline shift. All surgeons achieved successful ventricular cannulation using the EVD guide on first pass (100%). 13 out of 14 (93%) of the guide-assisted EVDs were optimally placed (Karkarla Grade 1). 1 (7%) guide-assisted EVD was suboptimally placed (Karkarla Grade 2). There was no intra or post-operative complication and there was no EVD revision. ConclusionsFor inexperienced surgeons, the 3D printed EVD guide can improve ventricular cannulation even in cases of altered ventricular anatomy. The benefit of 3D printing would also allow the guide to be widely adopted by other institutions worldwide.

A Practical Approach to Full-Arch Implant Prosthesis Fabrication Utilizing 3D-Printed Surgical Guide Index.

This paper presents an efficient method for fabricating a full-arch implant prosthesis within one day, using a verification index through a three-dimensional (3D)-printed surgical guide. The technique involves the use of simple impression coping and laboratory analogs to ensure accurate prosthesis placement. Directly using 3D-printed surgical guides as a verification index simplifies and streamlines the procedure, offering a significant clinical advantage. This approach provides a clinically relevant advancement in prosthodontic practices by demonstrating a practical and instructive approach to enhance treatment outcomes.

Application of image recognition-based tracker-less augmented reality navigation system in a series of sawbone trials

BackgroundThis study introduced an Augmented Reality (AR) navigation system to address limitations in conventional high tibial osteotomy (HTO). The objective was to enhance precision and efficiency in HTO procedures, overcoming challenges such as inconsistent postoperative alignment and potential neurovascular damage.MethodsThe AR-MR (Mixed Reality) navigation system, comprising HoloLens, Unity Engine, and Vuforia software, was employed for pre-clinical trials using tibial sawbone models. CT images generated 3D anatomical models, projected via HoloLens, allowing surgeons to interact through intuitive hand gestures. The critical procedure of target tracking, essential for aligning virtual and real objects, was facilitated by Vuforia’s feature detection algorithm.ResultsIn trials, the AR-MR system demonstrated significant reductions in both preoperative planning and intraoperative times compared to conventional navigation and metal 3D-printed surgical guides. The AR system, while exhibiting lower accuracy, exhibited efficiency, making it a promising option for HTO procedures. The preoperative planning time for the AR system was notably shorter (4 min) compared to conventional navigation (30.5 min) and metal guides (75.5 min). Intraoperative time for AR lasted 8.5 min, considerably faster than that of conventional navigation (31.5 min) and metal guides (10.5 min).ConclusionsThe AR navigation system presents a transformative approach to HTO, offering a trade-off between accuracy and efficiency. Ongoing improvements, such as the incorporation of two-stage registration and pointing devices, could further enhance precision. While the system may be less accurate, its efficiency renders it a potential breakthrough in orthopedic surgery, particularly for reducing unnecessary harm and streamlining surgical procedures.

Accuracy of Orthodontic Anchor Screw Placement Using a 3D-Printed Surgical Guide.

Background Although radiographs and computed tomography (CT) images are reviewed before temporary anchorage device (TAD) implantation, implantation of TADs exactly as planned is difficult. This study aimed to evaluate the accuracy of TAD implantation using an original surgical guide fabricated using cone-beam CT data and computer-aided design software. Methodology The studyparticipants included six experienced orthodontists who had implanted ≥20 TADs, and six inexperienced orthodontists who had never implanted a TAD. Maxillary dental typodont models with radiopaque tooth crowns and roots were used. A total of four TADs were implanted on the buccal sides: between the second bicuspid and first molars and between the first and second molars bilaterally. The accuracy of TAD implantation was examined in two groups: in 12 dental typodont models, TAD implantation was performed using a surgical guide (guide group), and in 12 dental typodont models, TAD implantation was performed without a surgical guide (freehand group). All dental typodont models implanted a total of 96 TADs.The TAD position was evaluated using the CT coordinate system and 3D image measurement software. Using the long axis of the TAD as a reference, the distance between the coronal and apical ends of the implanted TAD and those of the planned TAD, i.e., the ideal implantation position, was measured in both groups along the x, y, and z axes. The medians of the values were compared between the groups. Additionally, the presence of root contact was compared between the experienced and inexperienced orthodontists. Results On the x-axis, the linear deviations (median) of the coronal and apical ends of the TAD in the freehand group were 1.06 mm and 1.36 mm, respectively. In contrast, in the guide group, the deviations were 0.65 mm and 0.90 mm, respectively, and the difference was statistically significant (p = 0.002 and p = 0.005, respectively). On the y-axis, the deviations in the freehand group were 1.13 mm and 1.08 mm, respectively. In contrast, the deviations in the guide group were 0.71 mm and 0.79 mm, respectively, and only the coronal deviations were significantly different between the groups (p = 0.006). On the z-axis, the deviations in the freehand group were 1.44 mm and 1.86 mm, respectively. In contrast, the deviations in the guide group were 0.75 mm and 1.16 mm, respectively, and the difference was statistically significant (p = 0.006 and p = 0.002, respectively). Conclusions The use of a surgical guide allowed for more accurate TAD implantation. Additionally, TAD implantation using a guide prevented root damage.

Applications and accuracy of 3D-printed surgical guides in traumatology and orthopaedic surgery: A systematic review and meta-analysis.

Patient-Specific Surgical Guides (PSSGs) are advocated for reducing radiation exposure, operation timeand enhancing precision in surgery. However, existing accuracy assessments are limited to specific surgeries, leaving uncertainties about variations in accuracy across different anatomical sites, three-dimensional (3D) printing technologiesand manufacturers (traditional vs. printed at the point of care). This study aimed to evaluate PSSGs accuracy in traumatology and orthopaedic surgery, considering anatomical regions, printing methodsand manufacturers. A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Studies were eligible if they (1) assessed the accuracy of PSSGs by comparing preoperative planning and postoperative results in at least two different planes (2) used either computer tomography or magnetic resonance imaging (3) covered the field of orthopaedic surgery or traumatologyand (4) were available in English or German language. The 'Quality Assessment Tool for Quantitative Studies' was used for methodological quality assessment. Descriptive statistics, including mean, standard deviation, and ranges, are presented. A random effectsmeta-analysis was performed to determine the pooled mean absolute deviation between preoperative plan and postoperative result for each anatomic region (shoulder, hip, spine, and knee). Of 4212 initially eligible studies, 33 were included in the final analysis (8 for shoulder, 5 for hip, 5 for spine, 14 for knee and 1 for trauma). Pooled mean deviation (95% confidence interval) for total knee arthroplasty (TKA), total shoulder arthroplasty (TSA), total hip arthroplasty (THA)and spine surgery (pedicle screw placement during spondylodesis) were 1.82° (1.48, 2.15), 2.52° (1.9, 3.13), 3.49° (3.04, 3.93)and 2.67° (1.64, 3.69), respectively. Accuracy varied between TKA and THA and between TKA and TSA. Accuracy of PSSGs depends on the type of surgery but averages around 2-3° deviation from the plan. The use of PSSGs might be considered for selected complex cases. Level 3 (meta-analysis including Level 3 studies).

Effects of autoclaving and disinfection on 3D surgical guides using LCD technology for dental implant

BackgroundSurgical guides can improve the precision of implant placement and minimize procedural errors and their related complications. This study aims to determine how different disinfection and sterilization methods affect the size changes of drill guide templates and the mechanical properties of 3D-printed surgical guides made with LCD technology.MethodsWe produced a total of 100 samples. Forty surgical guides were fabricated to assess the implant drill guides’ surface and geometric properties. We subjected sixty samples to mechanical tests to analyze their tensile, flexural, and compressive properties. We classified the samples into four groups based on each analytical method: GC, which served as the control group; GA, which underwent autoclave sterilization at 121 °C (+ 1 bar, 20 min); GB, which underwent autoclave sterilization at 134 °C (+ 2 bar, 10 min); and GL, which underwent disinfection with 70% isopropyl alcohol for 20 min.ResultThe results show that sterilization at 121 °C and 134 °C affects the mechanical and geometric characteristics of the surgical guides, while disinfection with 70% isopropyl alcohol gives better results.ConclusionOur study of 3D-printed surgical guides using LCD technology found that sterilization at high temperatures affects the guides’ mechanical and geometric properties. Instead, disinfection with 70% isopropyl alcohol is recommended.

A Systematic Review of Microvascular Reconstruction Techniques in Head and Neck Surgery: Accessing Advancements in Surgical Methods and Functional Outcomes

In recent years, microvascular reconstruction in head and neck surgery has gained significant advancements. With advent of latest technological innovations in microvascular reconstruction techniques, now surgeons have better and more safe option of critical surgeries such as neck and head. Scientists now have a deeper understanding of anatomical complexities because of the latest knowledge and tools. In this systematic review, we aim to discuss the latest technological advancements in head and neck surgery and what kind of microvascular reconstruction techniques are performed with novel surgical methods. Innovations like Augmented Reality (AR) integration, patient-specific implants, and 3D-printed surgical guides have improved surgical outcomes. This review discusses dynamic microvascular reconstruction techniques for facial paralysis. We have emphasised the success of immediate functional gracilis transfer and chimeric flaps. We will discuss novel strategies such as microvascular alternative donor site technology and the adoption of immediate dental implants, which have also contributed to improved aesthetic and functional outcomes.

Treatment of excessive gingival display using conventional esthetic crown lengthening versus computer guided esthetic crown lengthening: (a randomized clinical trial)

BackgroundSurgical guides have been proposed in an attempt to reach more predictable outcomes for esthetic crown lengthening. The objective of the present study was to evaluate the effectiveness of esthetic crown lengthening using 3D-printed surgical guides in the management of excessive gingival display due to altered passive eruption type 1B.Materials and methodsSixteen patients diagnosed with altered passive eruption type 1B, were divided into two groups. In the control group, the procedure was carried out conventionally, and in the study group, a dual surgical guide was used. The parameters of wound healing (swelling, color, probing depth, bleeding index, and plaque index), pain scores, gingival margin stability, and operating time were assessed at 1 week, 2 weeks, 3 months, and 6 months postoperatively.ResultsThere was no statistically significant difference in terms of wound healing, pain scores, and gingival margin stability between both groups at different time intervals (P = 1), however, there was a statistical difference between both groups in terms of operating time with the study group being significantly lower (P < 0.001).ConclusionDigitally assisted esthetic crown lengthening helps shorten the operating time and reduces the possibility of human errors during the measurements. This will be useful in helping practitioners achieve better results.Practical implicationsThe conventional method remains to be the gold standard. However, shorter operating time and lower margins for errors will help reduce costs as the chair side time is reduced as well as the possibility for a second surgery is lower. This will improve patient satisfaction as well.

The clinical value of preoperative 3D planning and 3D surgical guides for Imhäuser osteotomy in slipped capital femoral epipysis: a retrospective study

BackgroundAccurate repositioning of the femoral head in patients with Slipped Capital Femoral Epiphysis (SCFE) undergoing Imhäuser osteotomy is very challenging. The objective of this study is to determine if preoperative 3D planning and a 3D-printed surgical guide improve the accuracy of the placement of the femoral head.MethodsThis retrospective study compared outcome parameters of patients who underwent a classic Imhäuser osteotomy from 2009 to 2013 with those who underwent an Imhäuser osteotomy using 3D preoperative planning and 3D-printed surgical guides from 2014 to 2021. The primary endpoint was improvement in Range of Motion (ROM) of the hip. Secondary outcomes were radiographic improvement (Southwick angle), patient-reported clinical outcomes regarding hip and psychosocial complaints assessed with two questionnaires and duration of surgery.ResultsIn the 14 patients of the 3D group radiographic improvement was slightly greater and duration of surgery was slightly shorter than in the 7 patients of the classis Imhäuser group. No difference was found in the ROM, and patient reported clinical outcomes were slightly less favourable.ConclusionsSurprisingly we didn’t find a significant difference between the two groups. Further research on the use of 3D planning an 3D-printed surgical guides is needed.Trial registrationApproval for this study was obtained of the local ethics committees of both hospitals.

Comparative evaluation of accuracy of implants placed with thermoplastic and three-dimensional-printed surgical guides: A randomized controlled trial.

The current study was planned to evaluate the accuracy of dental implant placement with two different types of surgical guides: Thermoplastic and three-dimensional (3D) printed. A total of 32 implants were placed in 20 healthy, partially dentate individuals with an isolated single missing tooth. The implant sites were randomly allocated into two treatment groups: Group A (thermoplastic implant surgical guide, n = 16 implants) and Group B (3D printed implant surgical guide, n = 16 implants). All the cases in both groups were digitally planned according to a defined protocol, and a comparison of the planned and actual implant positions was performed using the medical image analysis software. The differences in the outcome variables, i.e., angular deviation (AD), 3D error at the entry, 3D error at the apex (3D EA), vertical deviation (VD), and composite deviation, were statistically analyzed. All the outcome variables showed improvements, but statistically significant improvement was shown by AD (P = 0.005), 3D EA (P = 0.01), and VD (P = 0.007). The mean and standard deviation (SD) for AD, (3D EA), and VD were 5.58° ±1.93°, 0.96 ± 0.32 mm, and 0.58 ± 0.36 mm, respectively, for group A. The mean and SD for AD, (3D EA), and VD were 3.94° ± 0.64°, 0.64 ± 0.35 mm, and 0.29 ± 0.13 mm, respectively, for group B (P < 0.05). Within the limits of the study, dental implants placed using 3D-printed surgical guides were positioned clinically with greater accuracy, and fewer deviations were observed from their presurgical planned positions as compared to the thermoplastic surgical guides.

Cooling Efficiency of Sleeveless 3D-Printed Surgical Guides with Different Cylinder Designs.

Background and Objectives: Surgical guides might impede the flow of coolant to the implant drills during the preparation of the implant bed, potentially contributing to increased temperatures during bone drilling. The objective of this experimental study was to assess the cooling efficiency of various guiding cylinder designs for sleeveless surgical guides used in guided surgery. Materials and Methods: In this experimental study, surgical guides with three different guiding cylinder designs were printed. One group had solid cylinders (control) and two test groups (cylinders with pores and cylinders with windows). Forty customized polyurethane blocks with type III bone characteristics were fitted into the guide and fixed in a vise, and implant bed preparations were completed using a simplified drilling protocol with and without irrigation. An infrared thermographic camera was used to record the temperature changes during drilling at the coronal, middle, and apical areas. ANOVA test and Games-Howell post hoc test were used to determine significant thermal differences among groups. Results: A significant thermal increase was observed at the coronal area in the group without irrigation (39.69 ± 8.82) (p < 0.05). The lowest thermal increase was recorded at the surgical guides with windows (21.451 ± 0.703 °C) compared to solid (25.005 ± 0.586 °C) and porous surgical guides (25.630 ± 1.004) (p < 0.05). In the middle and apical areas, there were no differences between solid and porous cylinders (p > 0.05). Conclusions: 3D-printed sleeveless surgical guides with window openings at the guiding cylinders reduce the temperature elevation at the cortical bone in guided implant surgery.

Using Three-Dimensional Printing Technology to Solve Complex Primary Total Hip Arthroplasty Cases: Do We Really Need Custom-Made Guides and Templates? A Critical Systematic Review on the Available Evidence.

An extensive literature review was conducted to retrieve all articles centered on the use of 3D printing in the setting of primary THA. A total of seven studies were included in the present systematic review. Four studies investigated the use of 3D-printed surgical guides to be used during surgery. The remaining three studies investigated the benefit of the use of 3D-printed templates of the pelvis to simulate the surgery. The use of 3D printing could be a promising aid to solve difficult primary total hip arthroplasty cases. However, the general enthusiasm in the field is not supported by high-quality studies, hence preventing us from currently recommending its application in everyday practice.

An evaluation of the sources and extent of error in the position of implants placed using 3D-printed stereolithographic surgical guides.

Introduction/Background. Errors can be introduced in implant placement when using stereolithographically manufactured fully limiting surgical guides due to various factors, such as discrepancies in designing and manufacturing of surgical guides (intrinsic error), built-in variations in design of mechanical components of guide systems and implant dimensions (inherent error) or due to placement error by the operator (operator error). Aim. The aim of this study was to evaluate influence of various factors on implant position when using these guides. Materials and Methods. Prosthetically-driven implant positions were planned with pre-operative cone beam computed tomography (CBCT) data and digital scans using a computer aided designing (CAD) software. Static guided implant surgery was performed under local anaesthesia using fully limiting mucosa-supported surgical guide. Pre-operative and post-operative CBCTs were superimposed using surgical sleeve as a reference to evaluate the placement error by operator (N=12). To evaluate intrinsic error, standard tessellation language (STL) files of the virtual design of the surgical guides and the STL file obtained after scanning the 3D printed stereolithographic surgical guides were superimposed. Inherent error was calculated using a geometric model. Results. Intrinsic error was observed to be a major contributing factor in angular deviation of implant, linear deviation observed at implant shoulder as well as at implant apex. Operator error was observed to be a major contributing factor for mean vertical deviation observed at apex of implant. Conclusion. This study showed that accuracy of implant placement was largely influenced by discrepancies introduced during designing and manufacturing of stereolithographic surgical guides as compared to other sources.

An evaluation of the sources and extent of error in the position of implants placed using 3D-printed stereolithographic surgical guides.

Introduction/Background. Errors can be introduced in implant placement when using stereolithographically manufactured fully limiting surgical guides due to various factors, such as discrepancies in designing and manufacturing of surgical guides (intrinsic error), built-in variations in design of mechanical components of guide systems and implant dimensions (inherent error) or due to placement error by the operator (operator error). Aim. The aim of this study was to evaluate influence of various factors on implant position when using these guides. Materials and Methods. Prosthetically-driven implant positions were planned with pre-operative cone beam computed tomography (CBCT) data and digital scans using a computer aided designing (CAD) software. Static guided implant surgery was performed under local anaesthesia using fully limiting mucosa-supported surgical guide. Pre-operative and post-operative CBCTs were superimposed using surgical sleeve as a reference to evaluate the placement error by operator (N=12). To evaluate intrinsic error, standard tessellation language (STL) files of the virtual design of the surgical guides and the STL file obtained after scanning the 3D printed stereolithographic surgical guides were superimposed. Inherent error was calculated using a geometric model. Results. Intrinsic error was observed to be a major contributing factor in angular deviation of implant, linear deviation observed at implant shoulder as well as at implant apex. Operator error was observed to be a major contributing factor for mean vertical deviation observed at apex of implant. Conclusion. This study showed that accuracy of implant placement was largely influenced by discrepancies introduced during designing and manufacturing of stereolithographic surgical guides as compared to other sources.

On the thermal impact during drilling operations in guided dental surgery: An experimental and numerical investigation

In recent years, a major development in dental implantology has been the introduction of patient-specific 3D-printed surgical guides. The utilization of dental guides offers advantages such as enhanced accuracy in locating the implant sites, greater simplicity, and reliability in performing bone drilling operations. However, it is important to note that the presence of such guides may contribute to a rise in cutting temperature, hence increasing the potential hazards of thermal injury to the patient's bone. The aim of this study is to examine the drilling temperature evolution in two distinct methods for 3D-printed surgical dental guides, one utilizing an internal metal bushing system and the other using external metal reducers. Cutting tests are done on synthetic polyurethane bone jaw models using a lab-scale automated Computer Numeric Control (CNC) machine to find out the temperature reached by different drilling techniques and compare them to traditional free cutting configurations. Thermal imaging and thermocouples, as well as the development of numerical simulations using finite element modeling, are used for the aim. The temperature of the tools' shanks experienced an average rise of 2.4 °C and 4.8 °C, but the tooltips exhibited an average increase of around 17 °C and 24 °C during traditional and guided dental surgery, respectively. This finding provides confirmation that both guided technologies have the capability to maintain temperatures below the critical limit for potential harm to bone and tissue. Numerical models were employed to validate and corroborate the findings, which exhibited identical outcomes when applied to genuine bone samples with distinct thermal characteristics.

Customised 3D-Printed Surgical Guide for Breast-Conserving Surgery after Neoadjuvant Chemotherapy and Its Clinical Application.

For patients eligible to undergo breast-conserving surgery (BCS) after neoadjuvant chemotherapy, accurate preoperative localisation of tumours is vital to ensure adequate tumour resection that can reduce recurrence probability effectively. For this reason, we have developed a 3D-printed personalised breast surgery guide (BSG) assisted with supine magnetic resonance imaging (MRI) and image 3D reconstruction technology, capable of mapping the tumour area identified on MRI onto the breast directly using dual positioning based on the manubrium and nipple. In addition, the BSG allows the colour dye to be injected into the breast to mark the tumour region to be removed, yielding more accurate intraoperative resection and satisfactory cosmetic outcomes. The device has been applied to 14 patients from January 2018 to July 2023, with two positive margins revealed by the intraoperative biopsy. This study showed that the BSG-based method could facilitate precise tumour resection of BCS by accurately localising tumour extent and margin, promoting the clinical efficacy in patients with breast cancer as well as simplifying the surgical process.

3D-printed patient specific surgical guides: Balancing accuracy with practicality

IntroductionThree-dimensional (3D) printing technology has been used in orthopaedic surgery in recent years to manufacture customized surgical cutting jigs. However, there is scarcity of literature and information regarding the optimal parameters of an ideal jig. Our study aims to determine the optimum parameters to design surgical jigs that can produce accurate cuts, and remain practical for use, to serve as a guide for jig creation in future. Methods and materialsA biomechanical lab study was designed to investigate whether the thickness of a jig and the height of its cutting slot can significantly affect cutting accuracy. Surgical jigs were 3D printed in medical grade, and an oscillating sawblade was used to mimic intraoperative surgical cuts through the cutting slots onto wooden blocks, which were then analysed to determine the accuracy of cuts. ResultsStatistical analysis was performed on a total of 72 cuts. The cutting accuracy increased when the thickness of the jig increased, at all slot heights. The cutting accuracy also increased as the slot height decreased, at all jig thicknesses. Overall, the parameters for jig construction that yielded the most accurate cuts were a jig thickness of 15 mm, in combination with a slot height of 100 % of the width of the sawblade. Additionally, at a jig thickness of 15 mm, there was no statistically significant difference in cutting accuracy when increasing the slot height to 120 %. ConclusionThis study is the first to propose tangible parameters that can be applied to surgical jig construction to obtain reproducible accurate cuts. Provided that a jig of 15 mm thickness can be accommodated by the size of the wound, the ideal surgical jig with a superior balance of accuracy and useability is 15 mm thick, with a cutting slot height of 120 % of the sawblade thickness.

3D-Printed Zygomatic Sliding Surgical Guide: A novel surgical guide, An in vitro study.

3D-Printed Zygomatic Sliding Surgical Guide: A novel surgical guide, An in vitro study.

A Finite Element Analysis of a Tooth-Supported 3D-Printed Surgical Guide without Metallic Sleeves for Dental Implant Insertion

Static guided surgery for dental implant insertion is a well-documented procedure requiring the manufacturing of a custom-made surgical guide, either teeth-supported, mucosal-supported, bone-supported, or mixed (teeth-mucosal-supported), depending on the clinical situation. The guidance of the surgical drills during implant bed preparation could be undertaken using a sequence of different diameters of metal drill sleeves or, with the sleeves incorporated in the surgical guide, shank-modified drills, both clinically accepted and used with good results. Despite the great number of advantages associated with the use of guided surgery, one of the major risks is guide fracture during drilling for implant bed preparation. Therefore, the aim of the present study was to evaluate the surgical guides without metal sleeves and to simulate, with the aid of Finite Element Analysis (FEA), the use of such dentally supported guides for implant insertion. The FEA is performed in CATIA v5 software after defining the surgical guide mesh material and bone properties. A maximum stress of 6.92 MPa appeared on the guide at the special built-in window meant to allow cooling during drilling, and the maximum value of the guide displacement during drilling simulation was 0.002 mm. Taking into consideration the limits of the current research, the designed tooth-supported surgical guide can withstand the forces occurring during the surgery, even in denser bone, without the risk of fracture.

Comparison of the Three-Dimensional Accuracy of Guided Apicoectomy Performed with a Drill or a Trephine: An In Vitro Study

Guided apicoectomy performed with 3D-printed polymer-based static surgical guides is an emerging trend in endodontic surgery. Static-guided apicoectomy is carried out with either a drill or a trephine. The aim of this in vitro study was to assess the accuracy of osteotomy and apicoectomy performed through a polymer guide, with both drill and trephine, and to compare the accuracy achievable with the two instruments. Six plaster models of a maxilla master model with extracted human maxillary teeth in polymethyl-methacrylate resin were used. The modeled osteotomies were performed in these. The master model was CBCT-scanned, and digital surgical plans were prepared, based on which the surgical guides were printed. The plans contained both drill and trephine apicoectomies. Digital three-dimensional position analysis was performed with dedicated algorithms. A total of 39 drill and 47 trephine osteotomies were analyzed. A statistically significant difference between the two instruments was found only in the global deviation of the distal endpoint, indicating lower deviation for the trephine procedure (1.53 mm vs. 1.31 mm, p = 0.038). Nevertheless, from a clinical perspective, this distinction is inconsequential. The results suggest that, for all practical purposes, the two approaches to apicoectomy allow the same level of accuracy.