Accuracy of Guided Implant Insertion in Mandibular Free-End Saddle Areas Using Stereolithographic Surgical Stent

Abstract

INTRODUCTION: The success of implant therapy depends primarily on appropriate treatment planning and properly performed implant placement surgery.Guided implant surgery (template based guided cavity preparation and guided implant insertion) is effective to guide the implant placement.This can be achieved by means of a surgical guide Stent.Stents are designed in conventional methods or stereolithography which allows the fabrication of surgical guides from 3D computer generated models for precise placement of the implants. OBJECTIVES: Assess the accuracy of stereolithographic surgical stent to orientate implant insertion in mandibular free-end saddle areas. MATERIALS AND METHODS: A total of 12 implants will be placed in patients having mandibular free end-saddle areas selected from the outpatient section of the department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Alexandria University, after virtual implant planning with implant studio software, the implants will be inserted using stereolithographical design of surgical stent then measuring the deviation between the planned implant position before the surgery and the actual position of placed implant after surgical procedure. RESULTS: Evaluation of the accuracy of placement was done by measuring the overall deviations between virtually planned and surgically placed dental implants.The mean of total angular difference in implant with stereolithographic stent were 10.9 ± 9.4°.While The Mean of total coronal differences in stereolithographic guided implant were 0.96 mm ± 0.7 mm.The Mean of total apical differences in stereolithographic guided implant were 1.8 ± 1.3 mm CONCLUSIONS: The stereolithographic surgical template was sufficiently accurate in transferring the planned implant position to the surgical field relative to the implant angulation and point of entrance.

Accuracy of CBCT based computer assisted surgical guide for implant placement with tilted position in posterior atrophied mandible

“…This method has not been found in literature except in one study by Abd Alkader et al, 2020 [17} . Comparison between virtual and actual implants' distance to IAN showed a statistically significant difference, with a mean distance of 0.72 ± 0.25 mm for actual implants and 1.7 ± 0.56 mm for virtual implants, interpretation of this results raises an alarm that the distance of the actual implant to IAN is commonly lesser than that on virtual implants which could endanger the IAN if this was not considered in virtual planning. This finding actually coincides with that of Abd Alkader et al 2020 [17] who also found a significant difference in their comparison between virtual and actual implant distance to IAN as a means of CASG accuracy evaluation, but the reported values of this distance in their study (4.30 ± 2. 69 mm for virtual implants and 3.88 ± 2.23 for actual implants) were higher than those in ours.…”

“…When it comes to the horizontal deviation between actual and planned implant cervically; this study recorded a mean deviation of 1.15 ± 0.49 mm which was very close to the mean cervical deviation for clinical studies included in Bover-Ramos' meta-analysis (1.1 ± 0.09), it was also close to the those recorded by Di Giacomo et al 2012 [23] (1.26 ± 0.66 mm), Vieira et al 2013 [27] (1.42 ± 0.71 mm) and Abd Alkader et al 2020 [17] (0.96 ± 0.7 mm) in mandibular implants placed by mucosa supported stereolithographic CASG fixed with pins based on CBCT images. However, this cervical deviation is considered slightly higher than those recorded by Pettersson et al 2012 [24] (0.8 mm) in mandibular implants placed by mucosa supported selective laser sintering CASG fixed with pins based on CBCT images, and slightly lower than that recorded by Cassetta et al 2013 [30] (1.64 ± 71 mm) in mandibular implants placed by mucosa supported stereolithographic CASG fixed with pins based on MSCT images.…”

“…Computer assisted surgical guide (CASG) is a stent fabricated from the 3D virtual plane made on the pre-operative 3D images of the patients for precise transfer of this virtual plane to the surgical theater. Stereolithography is a commonly used technology for production of such types of stent via rapid prototyping [16,17] .…”