Accuracy of Computer-Assisted Flapless Implant Placement by Means of Mucosa-Supported Templates in Complete-Arch Restorations: A Systematic Review

Comparison of accuracy between single posterior immediate and delayed implants placed using computer guided implant surgery and a digital laser printed surgical guide: A clinical investigation

STATEMENT OF PROBLEM

The congruence of surgical implant placement with the preplanned position is important for anatomic and prosthetic precision, minimal complications, and increased longevity. The influence of implant placement timing on the surgical deviations in single posterior implants is unclear.

PURPOSE

The purpose of this clinical study was to compare deviations between preplanned and single posterior immediate and delayed implants placed using computer-guided digital light processing (DLP) surgical guides fabricated using intraoral scanning and cone beam computed tomography (CBCT).

MATERIAL AND METHODS

Implant surgery was performed on 24 participants requiring single immediate or delayed implants in the posterior maxillary and mandibular regions, for which the surgical site data were obtained from CBCT and intraoral scanning. Subsequently, virtual implant planning and DLP surgical guides were fabricated. Preimplant and postimplant placement CBCT scans were overlapped, and mean deviations for the immediate and delayed implant groups were calculated. The groups were compared with unpaired t tests (α=.05).

RESULTS

A total of 24 implants were placed, 12 in each group. In participants who received immediate implant placement, the mean ±standard deviation angular deviation, linear deviation at shoulder, linear deviation at apex, and vertical deviation were 1.03 ±0.70 degrees, 0.26 ±0.30 mm, 0.23 ±0.24 mm, and 0.39 ± 0.34 mm, respectively. In participants who received delayed implant treatment, the deviations were 0.53 ±0.60 degrees, 0.15 ±0.18 mm, 0.25 ±0.33 mm, and 0.17 ±0.10 mm, respectively. Significant differences between the 2 groups were found in the vertical deviation (P<.05).

CONCLUSIONS

The timing of the single posterior placement was associated with different deviations in the vertical direction. All deviations obtained were below the recommended values. DLP surgical guides fabricated from intraoral and CBCT scans provided accurate implant placement in immediate and delayed single posterior implants.

Translucent monolithic zirconia titanium-supported FP1 full-arch prosthesis: A novel proof of concept to address esthetic, functional, and biologic challenges

OBJECTIVE

Despite the wide clinical use of translucent zirconia for full-arch implant prostheses, reduced flexural strength and fracture toughness compared with high-strength opaque zirconia needs to be addressed. A novel proof of concept for FP1 full-arch prosthesis featured by translucent monolithic zirconia and titanium framework was presented.

CLINICAL CONSIDERATIONS

Computer-guided implant planning and surgery were executed and digitally designed FP1 temporary prosthesis prefabricated. Implant and prosthetic placement were achieved with a set of three-dimensional (3D)-printed templates. Implants were immediately loaded. After 4 months intraoral optical scan was taken to record implant coordinates, soft tissue anatomy, and temporary FP1 prosthesis. A novel digital workflow was used to design and mill overlaying translucent zirconia and anatomically shaped titanium framework with a scalloped soft-tissue interface. Final FP1 prosthesis was assembled cementing zirconia jacket on titanium counterpart.

CONCLUSIONS

Translucent zirconia supported by titanium framework can address esthetic and mechanical requirements of FP1 full-arch prosthesis, minimizing risk of fracture and providing a rigid and passive joint with supporting implants. The smooth and highly polished titanium surface with an anatomic design, tightly matching scalloped soft tissue interface, can limit food impaction, air and saliva leakage and contribute to overall biologic integration of FP1 full-arch prosthesis.

CLINICAL SIGNIFICANCE

Translucent monolithic zirconia featured with anatomically shaped titanium framework with scalloped transmucosal part, combining a pleasant esthetic outcome with increased flexural strength and fracture toughness, may be indicated to increase the clinical performance of FP1 full-arch prosthesis.

Clinical accuracy of partially guided implant placement in edentulous patients: A computed tomography-based retrospective study

OBJECTIVES

This retrospective study was intended to evaluate the clinical accuracy of partially guided template in guiding implant placement in edentulous patients.

METHODS

A total of 120 implants were placed in 24 patients with at least one completely edentulous arch with a partially guided system. Based on CBCT data, a repeatable method was used to measure linear and angular deviations of implants at 3D level in Mimics medical software. The influence of supporting tissue and implant region on the accuracy was assessed, followed by the evaluation of direction of linear deviations in biologically vital areas.

RESULTS

Linear deviations of all implants were 1.91 ± 0.68 mm, 1.47 ± 0.68 mm, and 1.02 ± 0.69 mm at apical, apical lateral, and apical vertical levels. When at the cervical, cervical lateral, and cervical vertical levels, the linear deviations were 1.53 ± 0.65 mm, 0.98 ± 0.53 mm, and 1.01 ± 0.69 mm, respectively. Angular deviation of all implants was 7.14 ± 3.41°. Implants guided by mucosa + tooth-supported templates showed higher linear deviations at apical vertical level (1.21 ± 0.72 mm vs. 0.86 ± 0.63 mm, p < .05) and cervical vertical level (1.18 ± 0.72 mm vs. 0.87 ± 0.63 mm, p < .05) than mucosa-supported templates, and implants in maxilla were found higher angular deviation than mandible (7.89 ± 3.61° vs. 6.29 ± 2.97°, p < .05).

CONCLUSIONS

The partially guided template served as clinically viable surgical assistance in implant placement in edentulous patients. When using mucosa + tooth-supported template or placing implants in maxilla, more caution was required, especially in biologically vital areas.

The accuracy of implant placement using a combination of static and dynamic computer-assisted implant surgery in fully edentulous arches: A prospective controlled clinical study

OBJECTIVE

To compare the accuracy of implant position, using a combination of static and dynamic computer-assisted implant surgery (CAIS), with either static, dynamic, or freehand implant placement, in fully edentulous arches.

MATERIALS AND METHODS

Twenty-one patients with a total of 88 fixtures were included. Implants were divided equally into four groups: a combination of static and dynamic CAIS (SD group), static CAIS (S group), dynamic CAIS (D group), and freehand placement (FH group). Angular deviation, as well as the 3D platform and apex deviations, were measured for all groups. Furthermore, the direction of implant deviation was recorded and compared.

RESULTS

The FH group showed significantly more deviation compared to all groups, considering all the aspects, and at both the implant platform and apex. A significant difference in angular deviation between the SD and S groups (p < .001), and between the SD and D groups (p < .001) was noted, favoring the SD group. When evaluating implant distribution, the FH group showed a tendency towards the buccal, apical, and distal directions at platform and apex, while in the D group, implants shifted more to the buccal. In contrast, the SD group did not show a trend toward any specific direction. The S and SD groups did not show a statistical significance considering any direction.

CONCLUSIONS

The combination of static and dynamic CAIS increases the accuracy of implant placement in fully edentulous arches when compared with either static or dynamic CAIS alone, as well as freehand placement.

Mandibular Flexure and Its Significance: An In Vivo Cone Beam-Computed Tomography Proof-of-Concept Study

The aim of this study was to assess intra-arch mandibular dimensional changes that may occur during mouth opening using cone beam-computed tomography (CBCT). Fifteen patients in need of any type of treatment whose execution considered a pre- and post-CBCT assessment consented and were enrolled. CBCTs were taken with the following settings: 90 kV, 8 mA, field of view (FOV) 140 by 100 mm (height and diameter), Voxel size 0.25 mm (high resolution). The pre-CBCT was executed in the maximum mandibular opening (MO), while the post-CBCT was in the maximum intercuspation (MI). A thermoplastic stent with radiopaque fiducial markers (steel ball bearings) was fabricated for each patient. Measurements were made using radiographic markers between contralateral canines and contralateral first molars and between ipsilateral canines and first molars on both sides. Paired t-tests were performed to evaluate the difference between open and closed positions on these four measurements. In the MO position were registered a significative tightening of the mandible at the canine (-0.49 mm, SD 0.54 mm; p < 0.001) and molar points (-0.81 mm, SD 0.63 mm; p < 0.001) and a significative shortening of the mandible on the right (-0.84 mm, SD 0.80 mm; p < 0.001) and left sides (-0.87 mm, SD 0.49 mm; p < 0.001). Within the study limitations, mandibular flexure determined a significant shortening and tightening between maximum intercuspation to maximum opening positions. Mandibular dimensional changes should be considered in light of other patient factors in the treatment planning of implant positioning and long-span complete arch implant-supported fixed prostheses in order to avoid technical complications.

Position of digitally guided implants in completely edentulous maxillae by using a modified double-scan and overlap of three digital surface protocol

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.

Dynamic and static computer-assisted implant surgery for completely edentulous patients. A proof of a concept

OBJECTIVES

To assess the accuracy and patient reported outcome measures (PROMs) of the computer-guided "double factor" technique for treating fully edentulous patients.

METHODS

A proof of concept prospective study was designed. Ten consecutive patients requiring full arch dental implant supported rehabilitation in a private practice were enrolled between October 2021 and March 2022. All patients were treated by means of an All-on-four®, and implants were planned and placed according to the "double factor" technique. This technique merges the static and dynamic computer-guided surgical approach in the same surgery. The primary outcome was the accuracy of implant placement, measured by overlapping post- and pre-operative cone-beam computerized tomography with the implant planning. Additionally, PROMs and patient quality of life after surgery were evaluated using different questionnaires. Descriptive and bivariate data analyses were performed. Statistical significance was considered for p < 0.05.

RESULTS

A total of 48 implants were placed using the "double factor" technique, and 12 full-arch immediate loading prostheses were delivered. The mean angular deviation was 3.74° (standard deviation [SD]: 2). The total linear deviation at the apex and platform of the implant was 1.25 mm (SD: 0.55) and 1.42 mm (SD: 0.64), respectively. No statistically significant differences were found between tilted and axial implants, the upper and lower jaw, or the right and left side. High self-reported satisfaction was registered, and the Oral Health Impact Profile-14 (OHIP-14) score improved postoperatively (p = 0.002).

CONCLUSIONS

The "double factor" technique is a valid and accurate treatment approach for fully edentulous patients.

CLINICAL SIGNIFICANCE

The double factor technique merges the advantages of both the dynamic and static computer assisted surgery approaches, affording accurate and predictable results when treating fully edentulous patients in a minimally invasive manner.

Immediate vs. Delayed Placement of Immediately Provisionalized Self-Tapping Implants: A Non-Randomized Controlled Clinical Trial with 1 Year of Follow-Up

This study aimed to examine the clinical and esthetic outcomes of immediately provisionalized self-tapping implants placed in extraction sockets or healed edentulous ridges one year after treatment. Sixty patients in need of a single implant-supported restoration were treated with self-tapping implants (Straumann BLX) and immediate provisionalization. The implant stability quotient (ISQ) and insertion torque were recorded intraoperatively. After one year in function, the implant and prosthesis survival rate, pink esthetic score (PES), white esthetic score (WES), and marginal bone levels (MBL) were assessed. Sixty patients received 60 self-tapping implants. A total of 37 implants were placed in extraction sockets and 23 in edentulous ridges, and then all implants were immediately provisionalized. All implants achieved a high implant stability with a mean insertion torque and ISQ value of 58.1 ± 14.1 Ncm and 73.6 ± 8.1 Ncm, respectively. No significant differences were found between healed vs. post-extractive sockets (p = 0.716 and p = 0.875), or between flap vs. flapless approaches (p = 0.862 and p = 0.228) with regards to the insertion torque and ISQ value. Nonetheless, higher insertion torque values and ISQs were recorded for mandibular implants (maxilla vs. mandible, insertion torque: 55.30 + 11.25 Ncm vs. 62.41 + 17.01 Ncm, p = 0.057; ISQ: 72.05 + 8.27 vs. 76.08 + 7.37, p = 0.058). One implant did not osseointegrate, resulting in an implant survival rate of 98.3%. All implants achieved PES and WES scores higher than 12 at the 1-year follow-up. The clinical use of newly designed self-tapping implants with immediate temporization was safe and predictable. The implants achieved a good primary stability, high implant survival rate, and favorable radiographic and esthetic outcomes, regardless of the immediate or delayed placement protocols.

Can computer-assisted implant surgery improve clinical outcomes and reduce the frequency and intensity of complications in implant dentistry? A critical review

Computer-assisted implant surgery (CAIS), either static or dynamic, is well documented to significantly improve the accuracy of implant placement. Whether the increased accuracy leads to a corresponding improvement in clinical outcomes has not yet been systematically investigated. The aim of this critical review was to investigate whether the use of CAIS can lead to reduction of complications as well as improved clinical and patient-reported outcomes (PROs) when compared with conventional freehand implant surgery. A comprehensive online search was conducted to identify studies where implants were installed with static computer-assisted implant surgery (s-CAIS)or dynamic computer-assisted implant surgery(d-CAIS) or combinations of the two, either compared with conventional free-hand implant placement or not. Seventy-seven studies were finally included in qualitative analysis, while data from three studies assessing postsurgical pain were suitable for a meta-analysis. Only a small number of the available studies were comparative. The current evidence does not suggest any difference with regard to intraoperative complications, immediate postsurgical healing, osseointegration success, and survival of implants placed with CAIS or freehand protocols. Intraoperative and early healing events as reported by patients in randomized clinical trials (RCTs) did not differ significantly between CAIS used with flap elevation and conventional implant placement. There is limited evidence that increased accuracy of placement with CAIS is correlated with superior esthetic outcomes. Use of CAIS does not significantly reduce the length of surgeries in cases of single implants and partially edentulous patients, although there appears to be a more favorable impact in fully edentulous patients. Although CAIS alone does not seem to improve healing and the clinical and PRO, to the extent that it can increase the utilization of flapless surgery and predictability of immediacy protocols, its use may indirectly lead to substantial improvements in all of the above parameters.

Is computer-guided implant placement with a flapless approach more accurate than with a flapped surgical approach?

Study design Retrospective cohort study.Cohort selection and data analysis In total, 89 implants were placed in 34 patients (19 men and 15 women; average 62.1 years of age) using computer-guided implant surgery with cone beam computed tomography (CBCT). All patients included in this study were adults and the computed-guided implant surgery was planned according to a digital guide protocol based on CBCT. Group 1 patients received the implants with the guide and flapped surgical approach, Group 2 with the guide and flapless approach. Group 3 was the drop-out group which included other patients in who the implant could not be placed according to the guide. CBCT data from before and after the surgeries were superimposed to evaluate the accuracy of implant positioning among all the groups. The differences in distance of the entry point (deviation distance) and in the degree of the insertion angle (deviation angle) were measured on the superimposed CBCT. Statistical analysis was performed with SPSS software and an independent sample t-test was done to analyse the difference of measurements among the groups.Results The authors observed greater accuracy in Group 2 in terms of deviation distance and angulation when compared to Group 1. The deviated position of the implant fixtures was greater in the drop-out group when compared to the guided groups in terms of the displacement of entrance point and the degree of insertion.Conclusions The authors concluded that flapless guided implant surgery is more accurate than flap guided implant surgery. The results of this study can be useful to clinicians in making decisions between flapless surgical approach and flapped approach when using a guide for implant placement.

Fully digital workflow for ear defect rehabilitation with an immediate implant-retained auricular prosthesis

The fully digital workflow for an immediate implant-retained auricular prosthesis procedure included computer-aided treatment planning, flapless surgery, and the prefabricated auricular prosthesis rehabilitation. This technique also encompassed the presurgery fabrication of the substructure of the implants and the definitive auricular prosthesis to ensure the smooth insertion of the ear prosthesis.