A technique for immediately restoring single dental implants with a CAD-CAM implant-supported crown milled from a poly(methyl methacrylate) block

Accuracy of Digital Impression Methods for Capturing the Peri-Implant Emergence Profile: A Systematic Review

BACKGROUND

Accurately replicating the emergence profile (EP) of conditioned soft tissue is pivotal for the success of implant-supported restorations. In the field of digital technology, various methods have emerged to capture EP. This review aims to critically assess current digital methodologies for capturing peri-implant EP.

MATERIAL AND METHODS

Prospective interventional or observational clinical studies focusing on digitally mapping the emergence profile (EP) around single implant-supported restorations were included. Systematic reviews, in vitro and animal studies, and those not emphasizing EP capture were excluded. A systematic search across four databases (MEDLINE, CENTRAL, Embase, Web of Science) was conducted on 7th August 2024 based on a previously registered protocol (PROSPERO registration number: CRD42023459484). Risk of bias was assessed with RoB 2, ROBINS-I, and JBI critical appraisal tools. Qualitative and quantitative analyses were carried out.

RESULTS

Twenty-four eligible studies were identified, comprising 5 dental techniques, 12 case reports, 1 randomized controlled study, 2 cross-sectional studies, and 4 cross-over studies. The studies reported semi-digital pathways, direct scanning, indirect scanning, coded-healing abutments, and individualized use of scan bodies. Notably, the direct scanning technique showed considerable soft tissue collapse. Similar results can be achieved with indirect scanning and the conventional method.

CONCLUSIONS

Indirect EP scanning appears as the most promising method for capturing peri-implant EP. However, a confirmation of this finding requires a quantitative analysis through randomized clinical trials.

A Review on CAD/CAM Yttria-Stabilized Tetragonal Zirconia Polycrystal (Y-TZP) and Polymethyl Methacrylate (PMMA) and Their Biological Behavior

Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) and polymethyl methacrylate (PMMA) are used very often in dentistry. Y-TZP is the most widely used zirconia dental ceramic, and PMMA has classically been used in removable prosthesis manufacturing. Both types of materials are commercialized in CAD/CAM system blocks and represent alternatives for long-lasting temporary (PMMA) or definitive (Y-TZP) implantological abutments. The aim of the present work is to reveal that human gingival fibroblasts (HGFs) have a favorable response when they are in contact with Y-TZP or PMMA as a dental implant abutment or implant-supported fixed prosthesis, and also to review their principal characteristics. We conducted an electronic search in the PubMed database. From an initial search of more than 32,000 articles, the application of filters reduced this number to 5104. After reading the abstracts and titles, we reduced the eligible articles to 23. Ultimately, we have included eight articles in this review.

A cast-free approach to fabricating an implant-supported interim restoration: A dental technique

A cast-free approach is described to fabricate an implant-supported interim restoration by using the postoperative cone beam computed tomography (CBCT) scan to locate the placed implant. A postoperative intraoral scan was aligned to the postoperative CBCT scan through a dental implant planning software program. An attached interim abutment and implant analog complex was then scanned and superimposed on the placed implant in the postoperative CBCT scan. Once the best alignment was achieved, a virtual cast was generated, and an interim restoration with bilateral positioning wings was fabricated on the interim abutment and inserted during the second-stage surgery. This technique offers a cast-free approach to inserting an implant-supported interim restoration immediately after the second-stage surgery to guide the healing of the soft tissue that can minimize chairside time and optimize the clinical workflow.

Fabrication of additively manufactured custom impression copings based on stock abutments

This article describes a dental implant impression technique using custom impression copings. The implant impression coping was designed by using a dental computer-aided design software program and manufactured by using additive methods. The impression copings were cemented to stock abutments, and the assemblies were used to make the definitive pick-up impression.

Fabrication technique for a custom implant emergence profile on 3D printed casts

A procedure is described for fabricating a removable resilient soft-tissue replica that accurately replicates the contoured emergence profile of an interim implant-supported restoration on a cast fabricated by 3D printing. The technique uses digital scanning and 3D printing technologies to produce a 3D printed replica of the implant-supported interim crown, which is then used to fabricate the custom soft-tissue replica. This straightforward technique allows the accurate replication of the emergence profile without retaining the interim crown or fabricating a new one. No additional clinical appointments are needed.

In vitro Comparative Study of Fibroblastic Behaviour on Polymethacrylate (PMMA) and Lithium Disilicate Polymer Surfaces

Polymethyl methacrylate (PMMA) and lithium disilicate are widely used materials in the dental field. PMMA is mainly used for the manufacture of removable prostheses; however, with the incorporation of CAD-CAM technology, new applications have been introduced for this material, including as a provisional implant attachment. Lithium disilicate is considered the gold standard for definitive attachment material. On the other hand, PMMA has begun to be used in clinics as a provisional attachment until the placement of a definitive one occurs. Although there are clinical studies regarding its use, there are few studies on cell reorganization around this type of material. This is why we carried out an in vitro comparative study using discs of both materials in which human gingival fibroblasts (HGFs) were cultured. After processing them, we analyzed various cellular parameters (cell count, cytoskeleton length, core size and coverage area). We analyzed the surface of the discs together with their composition. The results obtained were mostly not statistically significant, which shows that the qualities of PMMA make it a suitable material as an implant attachment.