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Updated: Jul 30, 2025
Real-Time Dynamic Navigation System for the Precise Quad-Zygomatic Implant Placement in a Patient with a Severely Atrophic Maxilla
Published on: October 18, 2021
Position of digitally guided implants in completely edentulous maxillae by using a modified double-scan and overlap
Jorge Troncoso-Pazos1, Pablo Matamala2, María Francisca Jusari3
1Founder and Director, Make Solid Digital Dental Implant Study Group, Santiago, Chile; and Director, Department of Dental Services, Santa Cruz Hospital, O'Higgins Health Service, Ministry of Health, Government of Chile, Santa Cruz, Chile.
Statement Of Problem:
In patients with a completely edentulous maxilla, the variability in resilience and mucosal thickness and the lack of teeth and rigid supporting structures may lead to poor adaptation of the surgical guide and significant variation in the definitive implant position. Whether a modified double-scan technique with overlap of surfaces will improve implant placement is unclear.
Purpose:
The purpose of this prospective clinical study was to evaluate the 3-dimensional position and the correlation of 6 dental implants in participants with a completely edentulous maxilla using a mucosa-supported flapless surgical guide designed with 3 matched digital surfaces obtained with a modified double-scan protocol.
Material And Methods:
Dental implants were installed with an all-on-6 protocol in the edentulous maxilla of participants at the Santa Cruz Public Hospital, Chile. A stereolithographic mucosa-supported template was fabricated from a cone beam computed tomography (CBCT) scan made with a prosthesis with 8 radiopaque ceramic spheres inserted and by scanning the same prosthesis with an intraoral scanner. The mucosa was obtained by digitally casting the relining of the removable complete denture in the design software program. After 4 months, a second CBCT scan was obtained to evaluate the position of the installed implants measured at 3 locations: apical, coronal, platform depth, and angulation. Differences in position between the 6 implants in the completely edentulous maxilla and their linear correlation at the measured points were compared with the Kruskal-Wallis and Spearman correlation tests (α=.05).
Results:
Sixty implants were installed in 10 participants (age 54.3 ±8.2 years; 7 women). The average deviation in the apical axis was 1.02 ±0.9 mm, coronal 0.76 ±0.74 mm, platform depth 0.92 ±0.8 mm, and the major axis angulation of the 6 implants was 2.92 ±3.65 degrees. The implant in the maxillary left lateral incisor region had the most significant deviation in apical and angular points (P<.05). A linear correlation between apical-to-coronal deviations and apical-to-angular deviations was observed for all implants (P<.05).
Conclusions:
A stereolithographic mucosa-supported guide designed with the overlap of 3 digital surfaces had average dental implant position values similar to those reported by systematic reviews and meta-analyses. In addition, implant position varied based on the location of the implant installation in the edentulous maxilla.
