Three-dimensional-printed scaffolds have received greater attention as an attractive option compared to the conventional bone grafts for regeneration of alveolar bone defects. Hydroxyapatite and tricalcium phosphates have been used as biomaterials in the fabrication of 3D-printed scaffolds. This scoping review aimed to evaluate the potential of 3D-printed HA and calcium phosphates-based scaffolds on alveolar bone regeneration in animal models. The systematic search was conducted across four electronic databases: Ovid, Web of Science, PubMed and EBSCOHOST, based on PRISMA-ScR guidelines until November 2021. The inclusion criteria were: (i) animal models undergoing alveolar bone regenerative surgery, (ii) the intervention to regenerate or augment bone using 3D-printed hydroxyapatite or other calcium phosphate scaffolds and (iii) histological and microcomputed tomographic analyses of new bone formation and biological properties of 3D-printed hydroxyapatite or calcium phosphates. A total of ten studies were included in the review. All the studies showed promising results on new bone formation without any inflammatory reactions, regardless of the animal species. In conclusion, hydroxyapatite and tricalcium phosphates are feasible materials for 3D-printed scaffolds for alveolar bone regeneration and demonstrated bone regenerative potential in the oral cavity. However, further research is warranted to determine the scaffold material which mimics the gold standard of care for bone regeneration in the load-bearing areas, including the masticatory load of the oral cavity.

Three-dimensional (3D) bioprinting technology has emerged as an ideal approach to address the challenges in regenerative dentistry by fabricating 3D tissue constructs with customized complex architecture. The dilemma with current dental treatments has led to the exploration of this technology in restoring and maintaining the function of teeth. This scoping review aims to explore 3D bioprinting technology together with the type of biomaterials and cells used for dental applications. Based on PRISMA-ScR guidelines, this systematic search was conducted by using the following databases: Ovid, PubMed, EBSCOhost and Web of Science. The inclusion criteria were (i) cell-laden 3D-bioprinted construct; (ii) intervention to regenerate dental tissue using bioink, which incorporates living cells or in combination with biomaterial; and (iii) 3D bioprinting for dental applications. A total of 31 studies were included in this review. The main 3D bioprinting technique was extrusion-based approach. Novel bioinks in use consist of different types of natural and synthetic polymers, decellularized extracellular matrix and spheroids with encapsulated mesenchymal stem cells, and have shown promising results for periodontal ligament, dentin, dental pulp and bone regeneration application. However, 3D bioprinting in dental applications, regrettably, is not yet close to being a clinical reality. Therefore, further research in fabricating ideal bioinks with implantation into larger animal models in the oral environment is very much needed for clinical translation.

Three-dimensional (3D) bioprinting is a unique combination of technological advances in 3D printing and tissue engineering. It has emerged as a promising approach to address the dilemma in current dental treatments faced by clinicians in order to repair or replace injured and diseased tissues. The exploration of 3D bioprinting technology provides high reproducibility and precise control of the bioink containing the desired cells and biomaterial over the architectural and dimensional features of the scaffolds in fabricating functional tissue constructs that are specific to the patient treatment need. In recent years, the dental applications of different 3D bioprinting techniques, types of novel bioinks, and the types of cells used have been extensively explored. Most of the findings noted significant challenges compared to the non-biological 3D printing approach in constructing the bioscaffolds that mimic native tissues. Hence, this review focuses solely on the implementation of 3D bioprinting techniques and strategies based on cell-laden bioinks. It discusses the in vitro applications of 3D-bioprinted scaffolds on cell viabilities, cell functionalities, differentiation ability, and expression of the markers as well as the in vivo evaluations of the implanted bioscaffolds on the animal models for bone, periodontal, dentin, and pulp tissue regeneration. Finally, it outlines some perspectives for future developments in dental applications.

Background: The values of plant-based products have taken on an expanding relevance in dentistry. Salvadora persica chewing stick (miswak) has been practiced for centuries and is recommended by the World Health Organization as a customary oral hygiene tool. The therapeutic effects of S. persica chewing stick are contributed by its mechanical cleansing action, active chemicals released, or the combination of these two actions. However, the S. persica chewing stick in its natural form can be difficult to maneuver in certain parts of the mouth. This concern has inspired the innovation of the S. persica toothbrush that is designed to merge the ease of use of a toothbrush with the beneficial natural properties of S. persica preserved in its bristle. The present study aimed to compare the clinical effectiveness between S. persica toothbrush, S. persica chewing stick and the standard toothbrush in plaque and gingivitis control. Methods: In this single-blinded and parallel randomized controlled trial, 78 participants were randomly divided into three groups to either use (i) S. persica toothbrush (MTB); (ii) S. persica chewing stick (MCS); or (iii) standard toothbrush (STB) in a standardized manner for three weeks. Plaque Index (PI) and Periodontal Inflamed Surface Area (PISA) values, measuring plaque levels and severity of gingivitis, respectively, were evaluated at baseline, one- and three-week post-interventions. Results: The MCS group showed a significant improvement in the mean PISA values of the anterior teeth compared to the MTB and STB groups (MCS: from 16.35 ± 10.03 to 3.41 ± 1.14; MTB: from 25.20 ± 14.01 to 3.57 ± 1.19; STB: from 26.54 ± 8.64 to 6.17 ± 0.86; p < .050). All three groups reported significant improvements (p < .001) in the plaque levels and the severity of gingivitis from baseline to three weeks after the intervention. Conclusions: Following correct techniques, S. persica toothbrush and chewing sticks are as effective as the standard toothbrush in plaque control and gingival health, which represent the reputed anti-plaque and anti-gingivitis properties of S. persica. Trial registration: This clinical trial was prospectively registered in ClinicalTrials.gov with registration NCT04650685 (25/11/2020).