Computer-Aided Design/Computer-Aided Manufacturing Milling of Allogeneic Blocks Following Three-Dimensional Maxillofacial Graft Planning

Digital workflow to produce esthetic space maintainers for growing patients

Digital workflows have been used to enhance the predictability of oral rehabilitations. However, techniques to digitally design and manufacture esthetic space maintainers by following a prosthetically driven treatment plan for young patients are lacking. This technique report describes a full digital workflow to produce computer-aided design and computer-aided manufacturing (CAD-CAM) esthetic space maintainers by using intraoral scans, a dental CAD software program, and a milling machine. CAD-CAM space maintainers can be provided for young patients with satisfactory patient compliance and with minimal chairside adjustment.

Custom-made computer-aided-design/ computer-assisted-manufacturing (CAD/CAM) synthetic bone grafts for alveolar ridge augmentation: A retrospective clinical study with 3 years of follow-up

PURPOSE

To report on the results obtained with computer-aided-design/ computer-assisted-manufacturing (CAD/CAM) custom-made synthetic hydroxyapatite/beta-tricalcium-phosphate (HA/beta-TCP) bone grafts in alveolar ridge augmentation for dental implant placement.

METHODS

The procedure included: (1) cone-beam computed tomography (CBCT) of the bone defect; (2) virtual design of the custom-made onlay bone grafts; (3) milling of grafts from a pre-formed block of synthetic HA/beta-TCP; and (4) bone reconstructive surgery. Implants were placed 8 months later. The patients were followed for 3 years. The study outcomes were: (1) intra- and immediate post-operative complications; (2) 8-month vertical and horizontal bone gain; (3) implant survival; (4) implant-crown success; and (5) peri-implant marginal bone loss (MBL).

RESULTS

Twenty-six patients underwent ridge augmentation with custom-made CAD/CAM HA/beta-TCP onlay grafts. Eight months later, these patients were rehabilitated with dental implants. During surgery, 25/26 (96.1%) of the grafts adapted well to the bone defect. Immediate post-operative complications were pain and swelling (2/26 patients: 7.6%), and bone graft exposure (3/26: 11.5%); one exposure led to infection, removal of the graft, and failure of the procedure. Excellent integration of the other grafts was observed 8 months after the regenerative procedure, with mean vertical and horizontal bone gains of 2.10 mm (± 0.35) and 2.96 mm (± 0.45), respectively. Twenty-five implants were placed and restored with single crowns. Three years later, all implants were in function. The 3-year implant crown success rate and peri-implant MBL were 92.0% and 0.7 mm (±0.19), respectively.

CONCLUSIONS

With custom-made CAD/CAM synthetic HA/beta-TCP onlay grafts reconstruction of small vertical and/or horizontal defects of the alveolar ridge was obtained; this enabled implant placement, with high implant-crown success rate after 3 years. Further studies are needed to validate this technique.

STATEMENT OF CLINICAL RELEVANCE

Custom-made CAD/CAM synthetic HA/beta-TCP onlay grafts may represent an option for regeneration of small bone defects prior to implant placement.

Factors Affecting Trueness of Intraoral Scans: An Update

Background: Intraoral scanning (IOS) technologies have been constantly developed and improved. This systematic review aimed at assessing studies in the recent literature describing factors that influence the trueness of intraoral scans. Methods: Comparative in vitro and in vivo (i.e., interventional and observational) studies that quantitatively assessed the trueness of intraoral scans and that identified factors significantly affecting IOS trueness values were considered eligible for inclusion. The PUBMED and EMBASE databases were searched for articles published in the last two years (from February 2020 to February 2022). Data assessment and extraction were performed according to the guidelines of the PRISMA statement. Results: The present search strategy yielded 13 publications. An initial screening of the publications was performed using abstracts and key words, and after application of exclusion criteria, a total of nine studies were finally identified as eligible to be discussed. Several factors significantly affecting IOS were identified. Conclusions: Studies using current IOS technologies revealed that the device, scanning distance, operator experience, rescanning and post-processing scans, conditions of the preparations and presence of adjacent teeth are factors significantly affecting IOS trueness.

Digital versus Conventional Workflow in Oral Rehabilitations: Current Status

In recent years, computer-aided design and computer-aided manufacturing (CAD-CAM) technology has developed along with its applications in dentistry, including several new techniques that are used in oral rehabilitation applications [...]

Fully Digital Workflow with Magnetically Connected Guides for Full-Arch Implant Rehabilitation Following Guided Alveolar Ridge Reduction

This technique report describes a fully digital workflow in which two surgical guides (i.e. one for alveolar bone reduction and the other for implant placement) are magnetically connected to ensure stability during full-arch implant surgery following guided bone reduction. Digital prosthesis design as well as virtual bone reduction and implant planning are developed from the superimposition of facial, intraoral and CBCT scans. With this technique, different surgical guides and interim poly(methylmethacrylate) (PMMA) fixed prosthesis are precisely connected with magnets after being digitally designed and 3D-printed. As a result, such magnetic connection allows for satisfactory stability of the implant surgical guide, as well as of the interim fixed PMMA fixed prosthesis during capture of screw-retained abutments.

Three dimensionally printed surgical guides for removing fixation screws from onlay bone grafts in flapless implant surgeries

The present technique report describes a digital workflow for flapless implant surgery after onlay block bone graft healing in the esthetic area. Virtual removal of block fixation screws and optimal single-tooth implant position and digital crown waxing were planned from cone beam computed tomography (CBCT) and intraoral scans. Two different surgical guides were digitally designed and 3D-printed to allow for flapless implant surgery. The first surgical guide was used to remove all 3 fixation screws from a healed onlay block graft, whereas the second guide was used to determine the implant position and direction. The present methodology may be considered a time-efficient flapless approach for placing implants in sites with block grafts.