As a growing field in dentistry, the practical education during the undergraduate curriculum in implant dentistry should be extended. Not only the theoretical background but also practical skills are crucial to place implants in patients. In order to determine the exact implant position, several positioning aids are available. In the present laboratory study, the accuracy of implant insertion using two different guiding modes in a group of inexperienced participants was assessed. After three-dimensional planning using the data of a cone beam computed tomography of artificial mandibles, surgical templates were manufactured by thermoforming. In region 35, a sleeve for the pilot drill was used, whereas in region 45, a sleeve allowing a full-guided implant insertion was inserted. Subsequently, a total of 104 implants were placed by 52 undergraduates. Radiographical assessment of the three-dimensional accuracy was performed. Furthermore, the time required to insert the implants was recorded. Statistical analysis followed. When comparing the three-dimensional accuracy of the virtually planned to the actual inserted implant, a statistically significantly higher accuracy in three-dimensional angulation was achieved for the full-guided (3.388 ± 1.647°) compared to the pilot-drill guided mode (5.792 ± 3.290°). Furthermore, the time required to insert the implant was shorter for the full-guided template (6.23 ± 1.78 min) vs. for the pilot-drill guided (8.84 ± 2.39 min). Both differences reached a statistical significance (p < 0.001). Within the limit of this laboratory study, the results suggest that inexperienced surgeons benefit from a full-guided implant insertion. However, the clinical effects have to be discussed as the mismatch was varying in the decimillimeter range.

Three dimensional (3D) printing allows additive manufacturing of patient specific scaffolds with varying pore size and geometry. Such porous scaffolds, made of 3D-printable bone-like calcium phosphate cement (CPC), are suitable for bone augmentation due to their benefit for osteogenesis. Their pores allow blood-, bone- and stem cells to migrate, colonize and finally integrate into the adjacent tissue. Furthermore, the pore size affects the scaffold’s stability. Since scaffolds in maxillofacial surgery have to withstand high forces within the jaw, adequate mechanical properties are of high clinical importance. Although many studies have investigated CPC for bone augmentation, the ideal porosity for specific indications has not been defined yet. We investigated 3D printed CPC cubes with increasing pore sizes and different printing orientations regarding cell migration and mechanical properties in comparison to commercially available bone substitutes. Furthermore, by investigating clinical cases, the scaffolds’ designs were adapted to resemble the in vivo conditions as accurately as possible. Our findings suggest that the pore size of CPC scaffolds for bone augmentation in maxillofacial surgery necessarily needs to be adapted to the surgical site. Scaffolds for sites that are not exposed to high forces, such as the sinus floor, should be printed with a pore size of 750 µm to benefit from enhanced cell infiltration. In contrast, for areas exposed to high pressures, such as the lateral mandible, scaffolds should be manufactured with a pore size of 490 µm to guarantee adequate cell migration and in order to withstand the high forces during the chewing process.

Background: To assess the long-term functional orthodontic outcome of the Tübingen palatal plate (TPP) in children with Robin sequence (RS) in comparison to age- and sex-matched healthy controls. Methods: Between 09/2019 and 10/2020, we performed orthodontic assessments in 41 children at our Department of Orthodontics. Included were patients with RS (17 non-syndromic; four syndromic) and healthy controls (n = 22, average age in both groups 9.9 y). Facial analyses of 2D images, digital study casts and cephalometric measurements were made. Results: The orthodontic examinations showed no statistically significant group differences regarding functional extraoral, intraoral and pharyngeal parameters, or in skeletal patterns. The relationship between the upper and lower incisors was significantly increased (overjet 4 (2–10) vs. 3 (0–9) mm; p = 0.01) with a significant deficit in the lower face proportions (Jaw Index 4.15 (1.9–9.6) vs. 2.98 (0–9); p = 0.02; Facial convexity angle 157 (149–173) vs. 159 (149–170); p = 0.01). Conclusion: Children with RS treated with the TPP showed normal long-term functional orthodontic outcomes, thanks to the functional adaption of the stomatognathic system. However, soft tissue growth did not completely match skeletal growth, resulting in a more convex facial profile.

Solid-state nuclear magnetic resonance (NMR) spectroscopy allows for the identification of inorganic species during the biomineral formation, when crystallite particles visible in direct imaging techniques have not yet been formed. The bone blocks surrounding dental implants in minipigs were dissected after the healing periods of two, four, and eight weeks, and newly formed tissues formed around the implants were investigated ex vivo. Two-dimensional ³¹P-¹H heteronuclear correlation (HETCOR) spectroscopy is based on the distance-dependent heteronuclear dipolar coupling between phosphate- and hydrogen-containing species and provides sufficient spectral resolution for the identification of different phosphate minerals. The nature of inorganic species present at different mineralization stages has been determined based on the ³¹P chemical shift information. After a healing time of two weeks, pre-stages of mineralization with a rather unstructured distribution of structural motives were found. After four weeks, different structures, which can be described as nanocrystals exhibiting a high surface-to-volume ratio were detected. They grew and, after eight weeks, showed chemical structures similar to those of matured bone. In addition to hydroxyapatite, amorphous calcium phosphate, and octacalcium phosphate, observed in a reference sample of mature bone, signatures of ß-tricalcium phosphate and brushite-like structures were determined at the earlier stages of bone healing.

For sinus grafting, different methods and materials are available. One possible shortcoming of particulate bone grafts is either overfilling or augmenting the planned implant area insufficiently. To overcome this risk and to determine the implant position prior augmentation, we present an approach using three-dimensional printed scaffolds. A patient with a remaining anterior dentition and bilateral severely atrophied posterior maxilla was seeking oral rehabilitation. The cone beam computed tomography (CBCT) showed residual bone heights between one and two millimeters. Following the three-dimensional reconstruction of the CBCT data, the positions of the implants were determined in areas 16 and 26. Three-dimensional scaffolds adapted to the topography of the sinus were virtually designed and printed using a calcium phosphate cement paste. Bilateral sinus floor augmentation applying the printed scaffolds with an interconnecting porosity followed. After nine months, a satisfying integration of the scaffolds was obvious. At the re-entry, vital bone with sufficient blood supply was found. One implant could be placed in positions 16 and 26, respectively. After five months, the implants could be uncovered and were provided with a temporary denture. The application of three-dimensionally printed scaffolds from calcium phosphate cement paste seems to be a promising technique to graft the severely atrophied posterior maxilla for the placement of dental implants.