Objectives: The aim of this study was to evaluate thermal effects of ceramic and metal implant drills during implant site preparation using a standardised bovine model.Material and Methods: A total of 320 automated intermittent osteotomies of 10‐ and 16‐mm drilling depths were performed using zirconium dioxide‐based and stainless steel drills. Various drill diameters (2.0/ 2.2, 2.8, 3.5, 4.2 mm ∅) and different cooling methods (without/ with external saline irrigation) were investigated at room temperature (21 ± 1°C). Temperature changes were recorded in real time using two custom‐built multichannel thermoprobes in 1‐ and 2‐mm distance to the osteotomy site. For comparisons, a linear mixed model was estimated.Results: Comparing thermal effects, significantly lower temperatures could be detected with steel‐based drills in various drill diameters, regardless of drilling depth or irrigation method. Recorded temperatures for metal drills of all diameters and drilling depths using external irrigation were below the defined critical temperature threshold of 47°C, whereas ceramic drills of smaller diameters reached or exceeded the harmful temperature threshold at 16‐mm drilling depths, regardless of whether irrigation was applied or not. The results of this study suggest that the highest temperature changes were not found at the deepest point of the osteotomy site but were observed at subcortical and deeper layers of bone, depending on drill material, drill diameter, drilling depth and irrigation method.Conclusions: This standardised investigation revealed drill material and geometry to have a substantial impact on heat generation, as well as external irrigation, drilling depth and drill diameter.

The aim of this in vitro study was to evaluate the differences in heat generation across the drilling techniques, depths, and irrigation conditions of static computer-assisted implant surgery (S-CAIS) and conventional implant preparation (CIP) using a standardized bone model for comparative investigation. A total of 240 automated intermittent experimental procedures of 10 and 12 mm drilling depths were performed during S-CAIS and CIP using stainless steel twist drills of three drill diameters (2.2, 2.8, and 3.5 mm) and two irrigation modes (without/external cooling) at room temperature. Temperature changes were recorded in real time using multiple temperature sensors in two distances to the osteotomy site. For comparison, a linear mixed model was fitted. The level of statistical significance was set at α = 0.05. Comparing the two surgical techniques, significant temperature differences could be observed using 3.5 mm drills: CIP yielded statistically higher temperatures during 10 and 12 mm drilling without irrigation (p = 0.0115 and p = 0.0253, respectively), while statistically higher temperatures were observed with S-CAIS and external irrigation at a 12 mm drilling depth (p = 0.0101). This standardized in vitro investigation demonstrated the impact of surgical technique, drilling depth, and irrigation mode on heat generation, indicating differences especially in drills of larger diameter.

Over the past few years, biomaterial-based periodontal tissue engineering has gained popularity. An ideal biomaterial for treating periodontal defects is expected to stimulate periodontal-derived cells, allowing them to contribute most efficiently to tissue reconstruction. The present study focuses on evaluating the in vitro behavior of human periodontal ligament-derived stromal cells (hPDL-MSCs) when cultured on gelatin/Polycaprolactone prototype (GPP) and volume-stable collagen matrix (VSCM). Cells were cultured onto the GPP, VSCM, or tissue culture plate (TCP) for 3, 7, and 14 days. Cell morphology, adhesion, proliferation/viability, the gene expression of Collagen type I, alpha1 (COL1A1), Vascular endothelial growth factor A (VEGF-A), Periostin (POSTN), Cementum protein 1 (CEMP1), Cementum attachment protein (CAP), Interleukin 8 (IL-8) and Osteocalcin (OCN), and the levels of VEGF-A and IL-8 proteins were investigated. hPDL-MSCs attached to both biomaterials exhibited a different morphology compared to TCP. GPP exhibited stronger capabilities in enhancing cell viability and metabolic activity compared to VSCM. In most cases, the expression of all investigated genes, except POSTN, was stimulated by both materials, with GPP having a superior effect on COL1A1 and VEGF-A, and VSCM on OCN. The IL-8 protein production was slightly higher in cells grown on VSCM. GPP also exhibited the ability to absorb VEGF-A protein. The gene expression of POSTN was promoted by GPP and slightly suppressed by VSCM. In summary, our findings indicate that GPP electrospun nanofibers effectively promote the functional performance of PDLSCs in periodontal regeneration, particularly in the periodontal ligament and cementum compartment.

The differentiation ability of human periodontal ligament mesenchymal stromal cells (hPDL-MSCs) in vivo is limited; therefore, some studies considered strategies involving their pre-differentiation in vitro. However, it is not known how the differentiation of hPDL-MSCs influences their immunomodulatory properties. This study investigated how osteogenic differentiation of hPDL-MSCs affects their ability to suppress CD4⁺ T-lymphocyte proliferation. hPDL-MSCs were cultured for 21 days in osteogenic differentiation or standard culture media. Allogeneic CD4⁺ T lymphocytes were co-cultured with undifferentiated and differentiated cells in the presence or absence of interferon (IFN)-γ, interleukin (IL)-1β or tumor necrosis factor (TNF)-α, and their proliferation and apoptosis were measured. Additionally, the effects of these cytokines on the expression of immunomodulatory or pro-inflammatory factors were investigated. Our data show that osteogenic differentiation of hPDL-MSCs reduced their ability to suppress the proliferation of CD4⁺ T lymphocytes in the presence of IFN-γ and enhanced this ability in the presence of IL-1β. These changes were accompanied by a slightly decreased proportion of apoptotic CD4⁺ in the presence of IFN-γ. The osteogenic differentiation was accompanied by decreases and increases in the activity of indoleamine-2,3-dioxygenase in the presence of IFN-γ and IL-1β, respectively. The basal production of interleukin-8 by hPDL-MSCs was substantially increased upon osteogenic differentiation. In conclusion, this study suggests that pre-differentiation strategies in vitro may impact the immunomodulatory properties of hPDL-MSCs and subsequently affect their therapeutic effectiveness in vivo. These findings provide important insights for the development of MSC-based therapies.

Artificial intelligence (AI)-assisted radiographic tools offer new opportunities for diagnostic training in dental education, but evidence regarding their effect on independent student performance remains limited. This prospective randomized pilot study evaluated whether four weeks of supplementary training with an AI-based radiographic diagnostic-support application improved dental students’ performance in caries detection and periodontitis classification compared with conventional learning materials. Of 140 randomized students, 56 were included in the final analysis (AI-assisted group, n = 25; control group, n = 31). Diagnostic performance was assessed using bitewing-based caries tasks and panoramic-radiograph-based periodontitis classification, and outcomes were additionally analyzed according to study phase. The prespecified primary endpoint, total diagnostic performance across caries and periodontal tasks, was not met: scores did not differ significantly between groups (p = 0.251). In secondary analyses, the AI-assisted group achieved numerically higher scores for several outcomes, although the difference in periodontitis extent (localized vs. generalized) was not statistically significant (p = 0.102). In an exploratory adjusted model that was not corrected for multiple comparisons, AI-assisted allocation was associated with better performance for the first caries response position (response position 1; p = 0.026); given the null result for the primary endpoint and the absence of correction for multiple testing, this finding should be regarded as hypothesis-generating rather than confirmatory. Study phase significantly influenced periodontitis grade and caries response position 1. Overall, these findings do not demonstrate a significant benefit of AI-assisted radiographic training on the primary outcome, but the isolated adjusted difference in one caries scoring component supports further evaluation of structured, faculty-supported integration of the AI application into undergraduate dental curricula.