3D Printing Approach in Dentistry: The Future for Personalized Oral Soft Tissue Regeneration.

Three-dimensional (3D) printing technology allows the production of an individualized 3D object based on a material of choice, a specific computer-aided design and precise manufacturing. Developments in digital technology, smart biomaterials and advanced cell culturing, combined with 3D printing, provide promising grounds for patient-tailored treatments. In dentistry, the "digital workflow" comprising intraoral scanning for data acquisition, object design and 3D printing, is already in use for manufacturing of surgical guides, dental models and reconstructions. 3D printing, however, remains un-investigated for oral mucosa/gingiva. This scoping literature review provides an overview of the 3D printing technology and its applications in regenerative medicine to then describe 3D printing in dentistry for the production of surgical guides, educational models and the biological reconstructions of periodontal tissues from laboratory to a clinical case. The biomaterials suitable for oral soft tissues printing are outlined. The current treatments and their limitations for oral soft tissue regeneration are presented, including "off the shelf" products and the blood concentrate (PRF). Finally, tissue engineered gingival equivalents are described as the basis for future 3D-printed oral soft tissue constructs. The existing knowledge exploring different approaches could be applied to produce patient-tailored 3D-printed oral soft tissue graft with an appropriate inner architecture and outer shape, leading to a functional as well as aesthetically satisfying outcome.

A novel three-dimensional bone chip organ culture.

OBJECTIVES: The objective of this study was to develop a 3D bone chip organ culture model. We aimed to collect in vitro evidence of the ability of vital bone chips to promote new bone formation. MATERIALS AND METHODS: We developed a 3D in vitro hypoxic bone chip organ culture model. Histology of the bone chips was performed before and after culture and immunohistochemistry after 3-week culture. The 3D culture supernatants were tested for the presence of pro-angiogenic growth factors, TGFß1, GADPH, bone alkaline phosphatase, osteocalcin, osteonectin, osteopontin, bone sialoprotein and collagen type I. RESULTS: Histology after culture revealed bone chips in a matrix of fibrin remnants and a fibrous-appearing matter. Collagen type I- and IV-positive structures were also identified. Cells could be seen on the surface of the bone chips, with spindle-shaped cells bridging the bone chip particles. Pro-angiogenic growth factors and TGFß1were detected in the 3D cell culture supernatants. The transcripts for osteocalcin, bone sialoprotein and collagen type I were revealed only via PCR. CONCLUSIONS: Our results indicate that bone chips in our 3D organ culture remain vital and may stimulate the growth of a bone-forming matrix. CLINICAL RELEVANCE: The use of autogenous bone chips for oral and maxillofacial bone augmentation procedures is widespread in clinical practice. The rationale for this is that if bone chips remain vital in vivo, they could provide an environment promoting new bone formation through growth factors and cells. This 3D culture method is an essential tool for investigating the behaviour of bone chips.

Human VAT-1: a calcium-regulated activation marker of human epithelial cells.

BACKGROUND AND AIMS: Human VAT-1 (hVAT-1) is a homologue of the synaptic vesicle membrane protein of Torpedo californica. Its coding gene is located near the BRCA1 locus and thus hVAT-1 may be linked to an inherited predisposition to breast and ovary cancer. However, the hVAT-1 protein expression pattern in normal epithelial tissues such as skin, mammary gland and ovary, as well as in tumours of the mammary gland and ovary, has not been studied. METHODS: To address this issue, an immunohistological analysis of biopsies of normal epidermis and lesional epidermis of bullous pemphigoid and pemphigus vulgaris patients was undertaken. RESULTS: hVAT-1-expression was observed in basal keratinocytes of lesional epidermis of bullous pemphigoid patients but not in normal epidermis or in lesional epidermis of pemphigus vulgaris patients. Moreover, hVAT-1 expression in HaCaT cells was found to be calcium-dependent. Normal and malignant mammary and ovary epithelium were found to be hVAT-1-negative. CONCLUSIONS: Our results indicate that hVAT-1 exerts a specific function in keratinocyte physiology, in particular in calcium-regulated processes, with no evident deregulation in malignancies of the breast and ovary.