Marginal and internal fit of 3D printed resin graft substitutes mimicking alveolar ridge augmentation: An in vitro pilot study

Abstract

Recent improvements in additive manufacturing technologies may facilitate the use of customized 3D printed grafts for horizontal and vertical augmentation of the atrophic alveolar ridge. The accurate fit of such grafts could reduce the clinical treatment time and contribute optimal bone regeneration. The aim of this in vitro study was to evaluate the marginal and internal fit of 3D printed resin grafts as they could be used for alveolar ridge augmentation. Alveolar ridge morphologic data were derived from the Cone Beam Computed Tomography (CBCT) scans of six patients with alveolar bone defects. These data were transferred to a segmentation program to produce virtual 3D reconstructions of the alveolar ridge models. Using a Computer Aided Design (CAD) program, the alveolar bone defects were defined and customized grafts were designed and both the defects as well as the grafts generated (CAM) as 3D projects. These projects were imported into a 3D printer and were manufactured in resin. Hereafter, the grafts were fitted to the defect sites of the corresponding models and new CBCT scans were performed. Based on these scans, measurements were made at the marginal and internal part of the fitted grafts to evaluate the marginal and internal fit, respectively. The statistical analysis revealed that the mean marginal fit was significantly better (P < 0.05) than the mean internal fit. The fit of the grafts was dependent on the shape and on the size of the grafts. Specifically, the total void surface between the fitted graft and the corresponding defect site was significantly larger in the large-defect grafts than the small-defect grafts (P < 0.05). Within the limitations of the study, it could be demonstrated that it is possible to fabricate 3D printed resin grafts with acceptable fit in customized shapes, when combining CBCT scans and computer aided design and 3D printing techniques.

Computer‐assisted bone augmentation, implant planning and placement: An in vitro investigation

“…This method increased the difficulty of placing and retaining the block grafts. Concurring with Stoop et al (2019), the results show that placing the customised blocks on a predefined ridge defect gives a good clinical fit. Despite the extended defect size and surface, the blocks could be comfortably positioned onto the defect at each attempt.…”

“…In contrast to the methods used in other studies, a large and smooth bone defect was artificially created (Stoop et al, 2019; Tuna et al, 2021). This method increased the difficulty of placing and retaining the block grafts.…”

“…It ranges from class 1 (absence of bone defect) to class 4 (a combined horizontal and vertical bone defect). The higher the class, the more extensive bone augmentation is required, and the authors recommend a delayed approach to inserting implants (Chiapasco & Casentini, 2018; Stoop et al, 2019).…”

“…Stoop et al (2019) analysed the marginal and internal fit of printed bone blocks of different sizes. They showed that a fully digital workflow using a 3D printed jaw and bone blocks of different sizes was accurate enough to meet the biological criteria for osseointegration.Considering implant osseointegration, another aspect of this study is the one-stage approach for implant placement after block fixation.…”

Techniques in clinical examination and treatment planning of maxillofacial prosthesis patients – A systematic review

“…It has been reported that the application of radiation-emitting seed insertion can effectively control the recurrence and metastasis of oral and maxillofacial gland-derived malignant tumors that could affect another part of the body. [20] However, the palate has an abundance of bone tissue compared to soft tissue. In addition to that, there are essential tissues and vital organs located in close proximity to the palate.…”