Effects of supporting conditions and anchor microscrew on the stabilization of the implant guide template during the drilling process: An in vitro study

Efficacy of digital templates in edentulous implant placement: a retrospective study

OBJECTIVES

The aim of the present study is to evaluate the accuracy of a digital template on the three-dimensional accuracy of edentulous implantation through a retrospective study to provide more clinical evidence for the use of digital templates in edentulous patient.

MATERIALS AND METHODS

This study evaluates the efficacy of a digital surgical template in edentulous jaws, comparing preoperative plans with postoperative outcomes across four metrics: platform, apex, depth, and angular deviations. Utilizing a patient with an edentulous maxilla as a case study, this research employs CBCT for preoperative and postoperative assessments, with deviations analyzed via 3-Shape software. Comparing these deviations with average deviations in lierature.

RESULTS

The average platform deviations at positions 12, 14, 16, 22, 24, 26 were 0.98 ± 0.03 mm, 1.43 ± 0.02 mm, 1.27 ± 0.04 mm, 1.35 ± 0.03 mm, 1.34 ± 0.02 mm, and 1.42 ± 0.03 mm, respectively. The average apex deviations were 1.28 ± 0.02 mm, 1.39 ± 0.03 mm, 1.47 ± 0.04 mm, 1.26 ± 0.04 mm, 1.40 ± 0.04 mm, and 1.48 ± 0.03 mm, respectively, the average angular deviations were 3.50°± 0.08°, 2.87°± 0.07°, 3.49°± 0.06°, 3.36°± 0.10°, 3.41°± 0.13°, and 3.69°± 0.11°, and average depth deviations were 0.29 ± 0.03 mm, 0.26 ± 0.05 mm, 0.59 ± 0.05 mm, 0.28 ± 0.04 mm, 0.47 ± 0.02 mm, 0.53 ± 0.03 mm. Compared with a total mean deviation of 1.2 mm (1.04 mm to 1.44 mm) of platform deviation, 1.4 mm (1.28 mm to 1.58 mm) of apex deviation, angular deviation of 3.5°(3.0° to 3.96°) and depth deviation of 0.2 mm (-0.25 mm to 0.57 mm) reported in literature. While all measured deviations fell within clinically acceptable limits, certain parameters exceeded the benchmarks, suggesting areas for improvement in digital surgical planning and execution.

CONCLUSIONS

This study indicates that while all measured deviations fell within clinically acceptable limits, certain parameters exceeded the benchmarks, suggesting areas for improvement in digital surgical planning and execution. Based on these data, the potential of digital guide plates to fulfill precision requirements in edentulous jaw implantation can be proved, contributing valuable insights into the optimization of implant surgery protocols.

CLINICAL RELEVANCE

Now, the digital template is accepted by many doctors. However, clinical research has not thoroughly verified whether the new digital technology is more accurate than traditional technology. So, this study aims to explore the effect of a whole-process digital template on edentulous implantation and provide more clinical evidence.

A method for assessing guide layout and error on implant accuracy

Functional and esthetic results require accurate implant placement. We aimed to develop a predictive method for assessing guide layout and error on implant accuracy. A mathematical model for position error analysis was constructed based on triangular mesh data. This model examines the relationship between the spatial shifts of multiple surfaces and the spatial shifts of specific points. It involves encasing these surfaces in a cuboid bounding box and expressing them in a local coordinate system. The influence of positioning surface error and layout of surgical guide were researched with a simulation test. The result shows that error in the implant site position is directly related to the error in the guide locating surface under the same layout. When the guide locating surface layout varies, as the length, width, and height of the minimum cuboid envelope increase, the maximum deviation in the implant site position decreases.

Accuracy of the novel digital non-cross-arch surgical guides with integration of tooth undercut retention and screw-bone support for implant placement in mandibular free-end

BACKGROUND

Large cross-arch free-end surgical guides can obscure the visual field, compromising surgical accuracy due to insufficient stability at the free-end. This in vitro study aims to evaluate the accuracy of novel digital non-cross-arch surgical guides designed for implant placement at the mandibular free-end, incorporating tooth undercut retention and screw-bone support.

MATERIALS AND METHODS

A mandibular dental model lacking left molars was utilized to fabricate unilateral (cross-arch) tooth-supported surgical guides (GT I, n = 20). Subsequently, two additional types of surgical guides were fabricated: GT II (covering two teeth, n = 20) and GT III (covering three teeth, n = 20). These novel surgical guides were designed to utilize the undercut of the supporting teeth for retention and enhance stability with screw-bone support at the guide's free-end. Furthermore, 60 identical guiding blocks were assembled on the three types of surgical guides to facilitate the implants' insertion. On a phantom head, 120 implant replicas were placed at the Federal Dentaire Internationale (FDI) teeth positions #36 and #37 on the dental model, employing a combination of surgical guides and guiding blocks. To assess accuracy, planned and placed implant positions were compared using intraoral optical scanning. Discrepancies in angulation and linear deviations, including the coronal/apical 3D deviations, lateral deviation as well as depth deviation, were measured. Statistical analysis was performed using two-way ANOVA and Bonferroni test (α = 0.05).

RESULTS

GT I exhibited significantly largest discrepancies, including angular and linear deviations at the crest and apex at every implant site. Especially in depth, at implant site #36, the mean deviation value of GT I (0.27 ± 0.13 mm) was twice as large as GT III (0.13 ± 0.07 mm), and almost twice as large as GT II (0.14 ± 0.08 mm). However, at implant site #37, this deviation increased to almost a five-fold relationship between GT I (0.63 ± 0.12 mm) and II (0.14 ± 0.09 mm), as well as between GT I and III (0.13 ± 0.09 mm). No significant discrepancies existed between the novel surgical guides at either implant site #36 or #37.

CONCLUSION

This study provides a practical protocol for enhancing accuracy of implant placement and reducing the size of free-end surgical guides used at mandibular molar sites.

The influence of guide stabilizers and their application sequences on trueness and precision of surgical guides in free end situations: An in vitro analysis

OBJECTIVES

To evaluate the impact of guide stabilizers and their application sequences on implant placement accuracy of guided implant surgery in multiple teeth loss at free end.

MATERIALS AND METHODS

In this study, 96 implants were placed in the regions of #34, #36, and #37 of 32 identical mandibular models. The influence of using guide stabilizers or not (group A and group B) and various guide stabilizers application sequences (group B: #34 → #36 → #37; group C: #36 → #34 → #37; group D: #37 → #34 → #36) on implant placement trueness and precision was investigated. Data were analyzed using T-tests and one-way ANOVA.

RESULTS

Group B showed significant benefits in enhancing implant placement precision. Compared to group A, it resulted in reducing 3D-deviation at crest and 2D deviation in vestibular-oral direction at both crest and apex. Furthermore, group D demonstrated greater improvement in global implant placement precision by reducing 2D deviation in mesial-distal direction at both crest and apex. Among the three different stabilizer application sequences, group D exhibited the highest level of implant placement precision.

CONCLUSIONS

In cases of missing teeth at distal free end, the use of guide stabilizers and their application sequences does not have a significant impact on implant placement trueness. However, they do improve implant placement precision compared to methods that do not utilize guide stabilizers. Specifically, applying a guide stabilizer first at the furthest implant site to change teeth loss classification from free end to edentulous space with posterior support is the most reliable sequence.

Cone Beam Computed Tomography-Based Evaluation of the Accuracy of Implant Surgery with Conventional (Free Hand) Implant Placement vs Computer Fabricated 3D Guide Implant Placement

Introduction

Dental implants have been used in a variety of conventional technique-based forms for many years which had its own drawbacks. With the advent of cone beam CT, proper surgical and prosthetic planning is possible now a days. To achieve ideal implant placement, good prosthetic fabrication and overall successful prognosis computer fabricated guide aided surgery have been developed.

Aim and Objective

The aim of this study was to compare and evaluate the accuracy of implant placement in partially edentulous patients with conventional free hand technique and computer fabricated guide of implant placement by comparing pre- and post-CBCT data.

Methods

The present split mouth study design was conducted with forty sample size on twenty randomly selected patients who were treated with bilateral partially edentulous sites requiring dental implants. Patients were treated with both conventional (free hand) technique and computer fabricated 3D guide aided technique of implant placement. Comparison of accuracy of implant placement was done by comparing the pre- and postoperative CBCT data in terms of mean coronal deviation, mean apical deviation and mean angular deviation.

Results and Conclusion

The results showed that there is no statistically significant difference between mean coronal deviation, mean apical deviation and mean angular deviation of planned and placed implants in both conventional technique (free hand technique) and computer fabricated 3D guide aided implant placement technique. Hence, this study concluded that conventional technique of implant placement is equally efficient in comparison with computer fabricated guide aided surgery in terms of accuracy of implant placement.

Fixation Pins Increase the Accuracy of Implant Surgery in Free-End Models: An In Vitro Study

PURPOSE

Implant surgical guides, in combination with implant planning software, have been designed for accurate surgery, especially in partial edentulism. The purpose of this study was to examine the effect of fixation pins of surgical guides on the accuracy of static computer-assisted implant surgeries in a maxillary free-end situation.

MATERIALS AND METHODS

This in vitro study was conducted to compare surgical guides using various fixation pin protocols in implant surgery. A patient dental model with missing teeth from maxillary right first premolar to third molar was used as the study model… Implant placement was planned at maxillary right first premolar, right first molar, and right second molar; Straumann full guide templates were designed and fabricated using the coDiagnostiX software. The experiment involved surgical guides with no fixation pins (NF), buccal unilateral fixation pin (BF), palatal unilateral fixation pin (PF), and bilateral fixation pins on the buccal and palatal sides (BPF), based on the position and number of fixation pins. The deviation between the actual and planned positions was used to evaluate implant accuracy. The fixation pin protocols were the primary predictive variables. Angular, 3D platform, and 3D apex deviations were the primary outcome variables. Statistical analysis was performed using the one-way analysis of variance and Tukey's test (α = 0.05).

RESULTS

NF generated the maximum angular deviation (3.65 ± 1.39°), 3D platform deviation (1.58 ± 0.55 mm), and 3D apex deviation (2.18 ± 0.79 mm), whereas BPF produced the minimum angular deviation (1.88 ± 0.86°), 3D platform deviation (1.09 ± 0.51 mm), and 3D apex deviation (1.53 ± 0.45 mm). A statistically significant difference between NF and BPF in the angular deviation, 3D platform, and apex deviation (P < .0001, P = .009, and P = .002, respectively) was identified. The unilateral fixation pin exerted a significant effect only on the angular accuracy (BF, P = .0018; PF, P = .0001).

CONCLUSION

In a maxillary free-end situation, templates with a fixation pin generate better implant accuracy than those without it. A bilateral fixation pin protocol may produce less deviation than those without fixation pins. The implant accuracy does not appear to be affected by the position of the unilateral fixation pin.

A comparative retrospective study of different surgical guide designs for static computer-assisted implant surgery in posterior single edentulous sites

AIM

The aim of this retrospective clinical study was to compare the accuracy of static Computer-assisted implant surgery (sCAIS) in posterior single edentulous patients using different surgical guide designs.

MATERIALS AND METHODS

Thirty-seven partially edentulous patients with a total of 54 implants were included in the study. Seventeen implants were included in Group 1-Unbounded Tooth-Mucosa Supported; 18 implants in Group 2-Unbounded Tooth Supported; and 19 implants in Group 3 (Control)-Bounded Tooth Supported. All partially edentulous patients were treated with fully guided implant surgery using the corresponding surgical guide. Discrepancies between the pre-planned and post-operative implant position were evaluated.

RESULTS

The mean angular deviation ± standard deviation (SD) was 2.91 ± 1.56°, 3.33 ± 1.72° and 2.25 ± 1.13° for Groups 1, 2, and 3, respectively. The mean ± SD 3D offset at base was 0.66 ± 0.29 mm, 0.77 ± 0.24 mm, and 0.49 ± 0.22 mm; and 3D offset at tip was 0.84 ± 0.45 mm, 1.07 ± 0.38 mm, and 0.75 ± 0.25 mm for Groups 1, 2, and 3, respectively. No statistically significant differences between groups were found for angular deviation. There were statistically significant differences between Groups 2 and 3 for 3D offset at base (p = .002) and 3D offset at tip (p = .010).

CONCLUSIONS

Different surgical guide designs for posterior single edentulous areas appear to be associated with the accuracy level of sCAIS. In unbounded sites, having additional posterior attached soft tissue support is preferable.

Effects of Groove Sealing of the Posterior Occlusal Surface and Offset of the Internal Surface on the Internal Fit and Accuracy of Implant Placements Using 3D-Printed Surgical Guides: An In Vitro Study

This study evaluated the internal fit and the accuracy of the implant placement position in order to determine how the surface shape of the tooth and the offset influence the accuracy of the surgical guide. The acquired digital data were analyzed in three dimensions using 3D inspection software. The obtained results confirmed that the internal fit was better in the groove sealing (GS) group (164.45 ± 28.34 μm) than the original shape (OS) group (204.07 ± 44.60 μm) (p < 0.001), and for an offset of 100 μm (157.50 ± 17.26 μm) than for offsets of 30 μm (206.48 ± 39.12 μm) and 60 μm (188.82 ± 48.77 μm) (p < 0.001). The accuracy of implant placement was better in the GS than OS group in terms of the entry (OS, 0.229 ± 0.092 mm; GS, 0.169 ± 0.061 mm; p < 0.001), apex (OS, 0.324 ± 0.149 mm; GS, 0.230 ± 0.124 mm; p < 0.001), and depth (OS, 0.041 ± 0.027 mm; GS, 0.025 ± 0.022 mm; p < 0.001). In addition, the entries (30 μm, 0.215 ± 0.044 mm; 60 μm, 0.172 ± 0.049 mm; 100 μm, 0.119 ± 0.050 mm; p < 0.001) were only affected by the amount of offset. These findings indicate that the accuracy of a surgical guide can be improved by directly sealing the groove of the tooth before manufacturing the surgical guide or setting the offset during the design process.