Ceramic Scaffolds for Bone Augmentation: Design and Characterization with SEM and Confocal Microscopy.

Bone scaffolds must fulfil numerous and sometimes contradictory characteristics: biocompatibility, bioactivity, high porosity, and appropriate mechanical strength. To tackle some of these issues, this study has several aims for the development of such scaffolds for dentistry applications: (i) to utilize appropriate materials (ceramics and sponges) and to introduce a novel, potentially performant ceramic material; (ii) to characterize the obtained scaffolds by using a range of methods; (iii) to compare and to correlate the assessment results with the scope to validate them reciprocally. There are two commercially available dental ceramics (i.e., Ceramco iC Natural Enamel (E) and Ceramco iC Natural Dentine (D), (DeguDent GmbH, Hanau-Wolfgang, Deutschland)) that are considered, as well as a new-developed porcelain (ceramic C). To obtain porous structures of scaffolds, each ceramic is introduced in two different sponges: a denser one, green (G) and a less dense one, blue (B). A total of 60 samples are manufactured and divided in six study groups, obtained by combining the above materials: GE, BE, GD, BD, GC, and BC (where the first letter represents the sponge type and the second one the utilized ceramic). Several methods are applied to characterize their chemical composition, as well as their macro- and micro-porosity: X-ray Diffraction (XRD), apparent porosity measurements, scanning electronic microscopy (SEM), and confocal microscopy (CM). The latter two methods image the inner (porous) and the outer/cortical (denser) areas of the samples. The results show a good porosity (i.e., dimensions and uniformity of pores) of around 65% for the final group BC, with satisfactory values of around 51% for BD and GC. A certain correlation is made between SEM, CM, and the apparent porosity results. The biocompatibility of the new ceramic C is demonstrated. Finally, a necessary trade-off is made with the mechanical strength of the obtained scaffolds, which was also evaluated. From this point of view, Group BD has the highest compressive strength of around 4 MPa, while Group BC comes second, with around 2 MPa. This trade-off between porosity and mechanical strength suggests a choice between Groups BC and BD, which are the best with regard to the porosity and mechanical strength criterium, respectively.

Scaffold-Type Structure Dental Ceramics with Different Compositions Evaluated through Physicochemical Characteristics and Biosecurity Profiles.

The design and development of ceramic structures based on 3D scaffolding as dental bone substitutes has become a topic of great interest in the regenerative dentistry research area. In this regard, the present study focuses on the development of two scaffold-type structures obtained from different commercial dental ceramics by employing the foam replication method. At the same time, the study underlines the physicochemical features and the biological profiles of the newly developed scaffolds, compared to two traditional Cerabone® materials used for bone augmentation, by employing both the in vitro Alamar blue proliferation test at 24, 48 and 96 h poststimulation and the in ovo chick chorioallantoic membrane (CAM) assay. The data reveal that the newly developed scaffolds express comparable results with the traditional Cerabone® augmentation masses. In terms of network porosity, the scaffolds show higher pore interconnectivity compared to Cerabone® granules, whereas regarding the biosafety profile, all ceramic samples manifest good biocompatibility on primary human gingival fibroblasts (HGFs); however only the Cerabone® samples induced proliferation of HGF cells following exposure to concentrations of 5 and 10 µg/mL. Additionally, none of the test samples induce irritative activity on the vascular developing plexus. Thus, based on the current results, the preliminary biosecurity profile of ceramic scaffolds supports the usefulness for further testing of high relevance for their possible clinical dental applications.

Alveolar and dental arch morphology in Angle Class II division 2 malocclusion: a comparative study.

OBJECTIVE: The aim of this study was to analyze the dental and alveolar intercanine, interpremolar and intermolar widths in patients with Class II/2 malocclusion and to compare the data with a patient group with normal occlusion and also with a patient group with Class II/1 malocclusion. MATERIALS AND METHODS: The study was conducted on 140 untreated patients with permanent dentition, aged 16 to 25 years, which were divided into three groups, according to Angle's classification of occlusion. The measurements of the dento-alveolar intercanine, interpremolar and intermolar widths were made on virtual study models, scanned using an optical 3D scanner. The unpaired (Student's) t-test was used to determine whether there were any significant differences between the Class II/2 and Class I groups and between Class II/2 and Class II/1 groups, respectively (p<0.05). RESULTS: Significant differences were found between Class II/2 and Class II/1 groups in the maxillary and mandibular intercanine widths. Comparing the Class II/2 and Class I groups, significant differences were found in the mandibular intercanine width, in the maxillary and mandibular interpremolar widths and also in the maxillary and mandibular intercanine and interpremolar alveolar widths. CONCLUSIONS: The maxillary and mandibular interpremolar widths and the intercanine and interpremolar alveolar widths were larger, while the mandibular intercanine width was shorter in the Class I group than in the Class II division 2 group. The mandibular intercanine width was longer and the maxillary intercanine width was shorter in the Class II division 1 group compared to the Class II division 2 group.