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| Title |
Surgical guides May Lead to Greater Accuracy When Placing Implants vs. Free-hand Placement, Possibly Leading to Better Restorability Outcomes |
| Clinical Question |
Do edentulous patients have better implant restorability outcomes when a surgical guide is used as compared to free-handed implant placement? |
| Clinical Bottom Line |
Even though surgical guides could increase the accuracy of implant placement as compared to free-handed surgery, the evidence is weak. The development of a “gold standard” for procedure protocol and for measuring the accuracy of placement would allow for better analysis and more accurate conclusions. |
| Best Evidence |
(you may view more info by clicking on the PubMed ID link) |
| PubMed ID |
Author / Year |
Patient Group |
Study type
(level of evidence) |
| #1) 32893013 | Guentsch / 2021 | 100 implants | In Vitro Study | | Key results | 100 total implants were evaluated, divided into 5 study groups: 3 surgical guides with different sleeve heights, 1 partial surgical guide used only during pilot drill, 1 free-hand. All tested implants were compared to the planned implant at the crestal level, and deviation was measured. The fully guided implants had the smallest deviation at 0.22 + 0.07 mm, followed by partially guided implants with 0.69 + 0.15 mm; the free-handed implants had the most deviation at 0.80 + 0.35 mm (P < 0.001). This indicates that fully guided implants have a higher reproducibility when compared to the original planned implant when completed outside of the mouth. | | #2) 33439558 | Zhang / 2020 | 38 in vivo human control trails of which 6 were evaluated specifically for guided vs. free-hand | Meta-Analysis | | Key results | Out of the 38 articles that fit the inclusion criteria for this review, only 6 satisfied the authors’ comparison methods for evaluating 3 measurements of implant placement with surgical guides vs. free-hand. These 6 articles differed in measurement methods and consistency, which could not be guaranteed, so specific measurements could not be evaluated. They could, however, show numerical trends among the categories of the coronal point [Std.MD 0.98 (CI 0.66, 1.29)], apical point [1.38 (CI 1.12, 1.63)], and angle [1.26 (CI 1.06, 1.47)]. The heterogeneity among these 6 studies was also evaluated. The I^2 was 43%, demonstrating moderate heterogeneity for evaluation at the coronal point of the implant. I^2 for the apical point and the angle were 8% and 0% respectively, displaying minimal to no heterogeneity. This data led to a conclusion that surgical guides led to more accurate implant placement when compared to free-hand placement with respect to the coronal point, apical point, and angle. | |
| Evidence Search |
implant placement AND surgical guide AND free hand
free hand AND surgical guide AND implant |
Comments on
The Evidence |
Guentsch/2021 was an in vitro study of 100 identical mandible replicas from a partially edentulous patient comparing 5 different implant placement groups. The control to which all groups were compared was based on an implant planning software program. There was a single operator who placed all 100 implants, which kept the experiment consistent with the handling of implants. The measurements were obtained in a reliable manner by taking the virtually planned (reference) files and superimposing the postoperative implant STL files. In this way, the results could be reproduced under the same conditions by having a before and after CBCT. This fulfilled the ability to compare all groups to the same reference standard.
The meta-analysis by Zhang/2020 concluded that surgically guided implant placement was more accurate than free-hand placement in respect to three measurements: coronal point, apical point, and angle. However, the evidence supporting this conclusion regarding the coronal point [Std.MD 0.98 (CI 0.66, 1.29)] is not strong. The heterogeneity between the studies regarding the coronal point was also moderate with I^2=43%, further weakening any conclusions from this evidence. There is greater statistical significance [1.26 (CI 1.06, 1.47)] and no heterogeneity for the evidence regarding the angle of the implant. The apical point lies somewhere between the other two measurements [1.38 (CI 1.12, 1.63); I^2=8%].
This review was limited by the heterogeneity among studies, and within the 6 included studies one variable had moderate heterogeneity. The overall heterogeneity may be due to a lack of a “gold standard” when measuring for the accuracy of placement. If a greater number of studies are done with a more uniform design, the results could be evaluated more straightforwardly. The higher accuracy measured at the angle, however, was supported with better evidence. This data point is more significant when discussing restorability. The angle of the implant is important in order to distribute occlusal forces correctly. Small changes in the angle of the implant are also significant when restoring a group of implants with a single prosthetic, such as an all-on-four fixed prosthesis. Further studies including the clinical outcome and restorability of implants placed with surgical guides vs. free-handed are needed. It is also important to note that the differences found between surgically guided and free-hand placement may not be a clinically significant amount due to the difficulty in comparing units of measurement.
|
| Applicability |
The selected articles concluded that there was a statistical significance in the accuracy of implant placement when using surgical guides. Zhang et al. presented their best evidence in regard to the deviation of the angle of the implant, and Guentsch et al. took measurements at the crest of the implant. The angle of the implant, as long as it is in bone, is a more clinically relevant measurement when considering restorability. However, the statistics performed by Zhang could not provide the measurement of the angle deviation, only a trend. A small deviation in the angle of implant placement could be inconsequential clinically, but a larger deviation could create significant complications in restorative outcomes.
The crest measurement by Guentsch et al. could be considered as well and may be related to the angle. This study used one practitioner to place all the implants, and a computer-based model to evaluate the accuracy. However, it was all done in-vitro. This cannot be directly translated to an actual human patient and does not account for the experience of the practitioner.
Because of the risk of significant deviation in the angle of the implant when placing it free-hand, the practitioner may consider a surgical guide particularly in areas where the correct angle may be difficult to visualize. A more accurate implant placement reduces complications such as patient discomfort, broken prostheses, and other persistent difficulties when the restorability of an implant is more complex or challenging. |
| Specialty/Discipline |
(General Dentistry) (Oral Surgery) (Periodontics) (Prosthodontics) (Restorative Dentistry) |
| Keywords |
surgical guides, free-handed implants, restorability, implant placement
|
| ID# |
3573 |
| Date of submission: |
10/22/2024 |
| E-mail |
nguyena23@livemail.uthscsa.edu |
| Author |
Amy Nguyen |
| Co-author(s) |
Sara Robison |
| Co-author(s) e-mail |
robisons@livemail.uthscsa.edu |
| Faculty mentor/Co-author |
Hassem Geha |
| Faculty mentor/Co-author e-mail |
geha@uthscsa.edu |
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?) |
post a rationale |
| None available | |
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Comments and Evidence-Based Updates on the CAT
(FOR PRACTICING DENTISTS', FACULTY, RESIDENTS and/or STUDENTS COMMENTS ON PUBLISHED CATs) |
post a comment |
| None available | |
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