Fully digital versus conventional workflow for horizontal ridge augmentation with intraoral block bone: A randomized controlled clinical trial

Evaluating the Effects of Dynamic Navigation on the Accuracy and Outcomes of the Autogenous Bone Ring Technique for Vertical Ridge Augmentation: A Pilot Randomized Controlled Trial

OBJECTIVES

Autogenous bone ring technique (BRT) is a one-stage vertical augmentation approach with simultaneous implant placement. The aim of this study was to compare the accuracy and efficacy of autogenous BRT assisted by dynamic navigation (DN) with freehand approach (FA) for vertical ridge augmentation.

MATERIALS AND METHODS

Twenty-four patients eligible for autogenous BRT were randomly assigned to DN or FA groups. Digital preoperative design was conducted for both groups. BRT surgeries were executed with or without the aid of DN in the two groups. Accuracy outcomes evaluated angular and linear deviations at the bone ring in the donor site (BR-D), recipient site (BR-R), and implant entry/apex between planned and actual positions revealed by cone-beam computed tomography. Vertical augmentation-related outcomes, surgical complications, and patient-reported outcomes were assessed over 6 months.

RESULTS

Twenty-four patients underwent surgery while one was lost to follow-up. The DN group showed significantly lower mean (SD) BR-R angular (3.58 [2.07] vs. 8.77 [4.20]°) and entry deviation (1.43 [0.51] vs. 2.01 [0.70] mm). For BR-D, the DN group had significantly lower angular (4.80 [2.62] vs. 12.97 [6.26]°), entry (1.45 [0.96] vs. 3.52 [1.54] mm), and apex deviation (1.28 [0.64] vs. 3.50 [1.47] mm) compared to the FA group. Implant angular deviation (3.74 [2.14] vs. 9.17 [4.39]°) and apex deviation (1.75 [0.44] vs. 2.35 [0.82] mm) was significantly lower in the DN group. In the FA group, one patient exhibited temporary lower lip hypoesthesia. No significant differences were observed in vertical bone gain, resorption, or patient-reported outcomes.

CONCLUSIONS

Compared to FA, DN may improve the accuracy of autogenous BRT procedures for vertical ridge augmentation while minimizing invasiveness.

TRAIL REGISTRATION

This study was registered at the Chinese Clinical Trial Registry (https://www.chictr.org.cn; Registration No. ChiCTR2200065585; registration date: 2022/11/09).

Guided transpositional bone blocks in esthetic zone: Surgical technique and case report

BACKGROUND

The ultimate objective of implant dentistry is to position the implant in a three-dimensional, prosthetic-driven location. This case highlights a guided approach for harvesting and positioning an autogenous bone block to restore a horizontal bone defect in the anterior maxilla.

METHODS

This case report describes a 55-year-old patient with horizontal bone deficiency in the anterior maxilla following teeth loss. Using specialized software, a surgical guide was designed to facilitate the harvesting of an autogenous bone block from the subnasal region in the same location where implants were planned to be placed. The graft was then repositioned and fixed with titanium screws, and the gaps were grafted with xenogenic bone particles and covered with an absorbable collagen membrane. After 6 months, the implants were placed, followed by prosthetic restoration.

RESULTS

A one-stage implant placement was performed after an uneventful healing period. The bone augmentation resulted in a ridge width of 8 mm for a net gain of 5 mm. After 4 months, the implants were loaded with a screw-retained zirconia bridge.

CONCLUSION

Guided transpositional bone blocks offer a predictable approach to treating horizontal bone defects in the esthetic zone. Utilizing digital planning and surgical guides enhances precision, making the result more predictable.

KEY POINTS

This case provides new information as it highlights a novel guided approach for harvesting and positioning an autogenous bone block to restore a horizontal bone defect in the anterior maxilla using a surgical guide. The keys to successful management of this case include using precise digital planning, the design and use of a surgical guide to accurately harvest the autogenous bone block, proper fixation of the graft and ensuring an uneventful healing period before implant placement and prosthetic restoration. The primary limitations to success in this case could involve the challenge of having adequate distance away from the nasal floor for harvesting and repositioning the autogenous bone block and potential complications during the healing period.

PLAIN LANUAGE SUMMARY

This report describes a modern technique for addressing bone loss in the upper front part of the mouth, crucial for placing dental implants correctly. A 55-year-old patient with insufficient bone was treated using a digital plan to precisely guide the movement of a bone piece from a nearby area to where it was needed. This guided approach involved designing a custom guide with computer software, securely attaching the bone, and using special materials to aid healing. After 6 months, the dental implants were successfully placed and fitted with new teeth, resulting in a stable and natural-looking outcome.

Accuracy of Guided Dual Technique in Esthetic Crown Lengthening: A Prospective Case-Series Study

OBJECTIVE

This study aimed to evaluate the efficacy and safety of a digitally guided dual technique during esthetic crown lengthening surgery. In addition, patient satisfaction and patient-reported outcomes were assessed.

MATERIALS AND METHODS

A prospective case series study was conducted. Cone-beam computed tomography and intraoral scans were used to design surgical guides, which were manufactured via 3D printing. The primary outcome was surgical accuracy, assessed by measuring the distance between the planned and final gingival margin positions using overlapping intraoral scans. Secondary outcomes included clinical crown length, gingival margin stability, pain, and patient satisfaction. Statistical analyses were performed using multilevel linear regression models, with significance set at p < 0.05.

RESULTS

Ten participants (87 teeth) were treated without complications. The mean duration of surgery was 66.5 min. The overall absolute deviation was 0.56 mm (95% CI: 0.48 to 0.65) at 6 months postoperatively. Clinical crown length increased significantly from baseline to the end of surgery (p < 0.001), with minimal reduction at 6 months (p = 0.479). Patient-reported outcomes indicated mild postoperative pain and high satisfaction with esthetic results.

CONCLUSIONS

The digitally guided dual technique for esthetic crown lengthening surgery is safe and effective, providing highly accurate outcomes. The technique also results in excellent patient satisfaction.

CLINICAL SIGNIFICANCE

The use of digitally guided dual techniques for ACL surgery enhances precision and safety, leading to highly accurate outcomes and improved patient satisfaction. This approach could be beneficial in clinical settings to ensure better esthetic and functional results.

Digital workflow for graft harvest and positioning in deficient anterior mandibles versus conventional technique: Randomized controlled trial

BACKGROUND

The cortical shell technique is frequently associated with technical drawbacks, such as the lack of anatomical guidance during shell harvest and graft. This study aims to assess the horizontal bone gain and accuracy of a digitalized protocol that incorporates two interlocking patient-specific stackable guides (PSSGs) to control the shell harvest, positioning, and fixation.

PATIENTS AND METHODS

Twenty patients with deficient anterior mandibles were randomly allocated; 10 patients received freehand symphyseal shell harvest and fixation (the control group), whereas the other 10 received fully guided harvest and graft (study group) using (PSSGs), the first aided an accurate shell harvest, whereas the second conveyed shell fixation. The interposition gap among both groups was loaded with an equal mix of xenogeneic and autogenous particulates. The mean radiographic bone gain among both groups was calibrated 6 months postoperatively, and the accuracy of the digital plan was assessed by superimposing and comparing the virtually planned horizontal bone dimensions with the immediate postoperative actual bone dimensions.

RESULTS

The mean 6-month postoperative horizontal bone gain value of the study group was recorded as (4.97 ± 0.73) mm versus (4.45 ± 0.61) mm for the control group, with a statistically insignificant mean gain difference of (0.52) mm, (p = 0.101). The mean virtual preplanned horizontal bone gain was recorded (5.4 ± 0.6) versus (5.4 ± 0.6) for the immediate postoperative actual bone gain, which was also statistically insignificant (p = 0.9).

CONCLUSION

The (PSSGs) provided a precise method for graft harvest, position, and fixation, resulting in satisfactory alveolar ridge dimensions with intimate accuracy.

Digital planning and bone regenerative technologies: A narrative review

OBJECTIVES

The aim of this narrative review was to explore the application of digital technologies (DT) for the simplification and improvement of bone augmentation procedures in advanced implant dentistry.

MATERIAL AND METHODS

A search on electronic databases was performed to identify systematic reviews, meta-analyses, randomized and non-randomized controlled trials, prospective/retrospective case series, and case reports related to the application of DT in advanced implant dentistry.

RESULTS

Seventy-nine articles were included. Potential fields of application of DT are the following: 1) the use of intra-oral scanners for the definition of soft tissue profile and the residual dentition; 2) the use of dental lab CAD (computer-aided design) software to create a digital wax-up replicating the ideal ridge and tooth morphology; 3) the matching of STL (Standard Triangulation Language) files with DICOM (DIgital COmmunication in Medicine) files from CBCTs with a dedicated software; 4) the production of stereolithographic 3D models reproducing the jaws and the bone defects; 5) the creation of surgical templates to guide implant placement and augmentation procedures; 6) the production of customized meshes for bone regeneration; and 7) the use of static or dynamic computer-aided implant placement.

CONCLUSIONS

Results from this narrative review seem to demonstrate that the use of a partially or fully digital workflow can be successfully used also in advanced implant dentistry. However, the number of studies (in particular RCTs) focused on the use of a fully digital workflow in advanced implant dentistry is still limited and more studies are needed to properly evaluate the potentials of DT.

Subperiosteal Ridge Augmentation Technique Utilizing Sticky Bone: A Case Series

This case series presents the application of a novel minimally invasive technique for augmenting ridge defects across four edentulous sites, thereby circumventing common postoperative complications associated with conventional ridge augmentation techniques. The case series details three cases encompassing four edentulous sites with class I and III ridge defects. This approach uses a minimally invasive subperiosteal technique for ridge augmentation, followed by a delayed implant placement. Subperiosteal incisions were made mesial to the edentulous sites, and subperiosteal pouches were created using tunneling instruments. Sticky bone (comprising injectable platelet-rich fibrin (IPRF) and xenograft) was applied to the pouches, followed by Vicryl suturing. The cone-beam computed tomography (CBCT) assessed dimensional changes between baseline and 180 days post-ridge augmentation. Subsequently, during implant insertion after 180 days, bone samples were collected, decalcified using 10% formic acid, and sectioned to a thickness of 5 µm. Histological analysis of the bone samples was conducted using a bright field microscope, while histomorphometric analysis was carried out using Image J software. The modified subperiosteal tunneling technique employed in this case report, coupled with using sticky bone as an augmentation material, demonstrates promise as a reliable method for ridge augmentation.

Transformable Carbonate Apatite Chains as a Novel Type of Bone Graft

The aging global population is generating an ever-increasing demand for bone regeneration. Various materials, including blocks, granules, and sponges, are developed for bone regeneration. However, blocks require troublesome shaping and exhibit poor bone-defect conformities; granules migrate into the surrounding tissues during and after filling of the defect, causing handling difficulties and complications; and sponges contain polymers that are subject to religious restrictions, lack osteoconductivity, and may cause inflammation and allergies. Herein, carbonate apatite chains that overcome the limitations of conventional materials are presented. Although carbonate apatite granules migrate, causing inflammation and ectopic calcification, the chains remain in the defects without causing any complications. The chains conform to the defect shape and transform into 3D porous structures, resulting in faster bone regeneration than that observed using granules. Thus, these findings indicate that even traditional calcium phosphates materials can be converted to state-of-the-art materials via shape control.

Hard tissue stability outside the buccal bone arch contour after guided bone regeneration in the anterior maxilla: A retrospective cohort radiographic study

OBJECTIVES

To radiographically evaluate the stability of the bone substitute augmented outside the buccal bony arch contour in the maxillary esthetic zone.

MATERIALS AND METHODS

Patients who missed a single anterior tooth and received simultaneous GBR in implant surgery were included. The contralateral homonymous area of the implant site was horizontally mirrored as the individual bone arch contour. According to the relative position of the postoperative buccal grafts and bone arch contour at the implant shoulder, 62 patients were allocated into the outside-contour (OC) and inside-contour (IC) groups. Cone-beam computed tomography was performed before surgery, after implant insertion, before re-entry surgery, and at follow-up. The profilometric changes of the buccal bone plate were analyzed via the bone distance to the mirrored bony contour.

RESULTS

At the implant shoulder, the bone distance in the OC group was higher than that in the IC group, with statistically significant differences at re-entry surgery and follow-up. However, the bone grafts outside the bone arch contour were reduced into the contour after remodeling and showed more bone resorption than the IC group. At other vertical levels below the implant shoulder, bony grafting of overcontour 1-2 mm range was favorable to regenerate stable bone plates reaching the individual contour at follow-up.

CONCLUSIONS

The overaugmented bone outside the buccal bone arch contour tended to remodel into the original contour, which indicates that the anterior bone arch contour is worthy of careful observation for deciding buccolingual implant position and bone augmentation width.

Clinical feasibility evaluation of a digital workflow of prosthetically oriented onlay bone grafting for horizontal alveolar augmentation: a prospective pilot study

BACKGROUND

Onlay bone grafting is considered highly reliable for reconstructing severe horizontal bone defects. A critical problem is how to achieve precise position of the bone block to control alveolar ridge dimensions. This research aims to establish a digital workflow for prosthetically oriented onlay bone grafting and evaluate its accuracy and efficiency.

METHODS

This prospective pilot study investigated eight patients who required implant restoration in the esthetic area with horizontal alveolar bone defects. The workflow includes preoperative virtual planning, design and manufacture of patient-specific templates, bone grafting surgery, and implant insertion. Primary outcomes were graft accuracy, defined by root mean square estimate (RMSE) values between preoperatively designed and actual implanted outer contours of bone blocks. Secondary outcomes were bone graft and implant success rates. Besides, the surgeons used the visual analog scale (VAS) to rate the intuitiveness, ease of understanding, and helpfulness of the workflow.

RESULTS

No bone grafts or implants failed in any of the eight patients, resulting in a 100% success rate. The RMSE values between the preoperative design and the implanted outer contour of bone blocks were 0.41 ± 0.15 mm. The digital approach showed advantages in intuitiveness (9.3 ± 0.5), understanding (9.0 ± 0.5), and helpfulness (8.4 ± 1.1) according to surgeons' VAS scores.

CONCLUSIONS

A digital workflow provided encouraging results, in terms of accuracy and efficacy, for horizontal bone augmentation.

TRIAL REGISTRATION

This study was registered in the National Clinical Trials Registry in 16/02/2023 under the identification number ChiCTR2300068361.

Accuracy and Technical Predictability of Computer Guided Bone Harvesting from the Mandible: A Cone-Beam CT Analysis in 22 Consecutive Patients

This study assesses the accuracy and technical predictability of a computer-guided procedure for harvesting bone from the external oblique ridge using a patient-specific cutting guide. Twenty-two patients needing bone augmentation for implant placement were subjected to mandibular osteotomy employing a case-specific stereolithographic surgical guide generated through computer aided design. Differences between planned and real cut planes were measured comparing pre- and post-operative Cone Beam Computed Tomography images of the donor site according to six validated angular and displacement indexes. Accuracy and technical predictability were assessed for 119 osteotomy planes over the study population. Three different guide fitting approaches were compared. An average root-mean-square discrepancy of 0.52 (0.30-0.97) mm was detected. The accuracy of apical and medial planes was higher than the mesial and distal planes due to occasional antero-posterior guide shift. Fitting the guide with an extra reference point on the closest tooth performed better than using only the bone surface, with two indexes significantly lower and less disperse. The study showed that the surgical plan was actualized with a 1 mm safety margin, allowing effective nerve preservation and reducing technical variability. When possible, surgical guide design should allow fitting on the closest tooth based on both radiological and/or intra-oral scan data.