Senescence is related to the loss of cellular homeostasis and functions, which leads to a progressive decline in physiological ability and to aging-associated diseases. Since mitochondria are essential to energy supply, cell differentiation, cell cycle control, intracellular signaling and Ca²⁺ sequestration, fine-tuning mitochondrial activity appropriately, is a tightrope walk during aging. For instance, the mitochondrial oxidative phosphorylation (OXPHOS) ensures a supply of adenosine triphosphate (ATP), but is also the main source of potentially harmful levels of reactive oxygen species (ROS). Moreover, mitochondrial function is strongly linked to mitochondrial Ca²⁺ homeostasis and mitochondrial shape, which undergo various alterations during aging. Since mitochondria play such a critical role in an organism’s process of aging, they also offer promising targets for manipulation of senescent cellular functions. Accordingly, interventions delaying the onset of age-associated disorders involve the manipulation of mitochondrial function, including caloric restriction (CR) or exercise, as well as drugs, such as metformin, aspirin, and polyphenols. In this review, we discuss mitochondria’s role in and impact on cellular aging and their potential to serve as a target for therapeutic interventions against age-related cellular dysfunction.

The naturally occurring polyphenol, resveratrol (RSV), is known for a broad range of actions. These include a positive impact on lifespan and health, but also pro-apoptotic anti-cancer properties. Interestingly, cell culture experiments have revealed a strong impact of RSV on mitochondrial function. The compound was demonstrated to affect mitochondrial respiration, structure and mass of mitochondria as well as mitochondrial membrane potential and, ultimately, mitochondria-associated cell death pathways. Notably, the mitochondrial effects of RSV show a very strict and remarkable concentration dependency: At low concentrations, RSV (50 μM) triggers changes in (sub-)cellular Ca²⁺ homeostasis, disruption of mitochondrial membrane potential and activation of caspases selectively yielding apoptotic cancer cell death, in vitro and in vivo. In this review, we discuss the promising therapeutic potential of RSV, which is most probably related to the compound’s concentration-dependent manipulation of mitochondrial function and structure.

Bone preservation is a requirement for long-term stability of dental prostheses, which is all the more important in the posterior mandible, given the particular challenges these areas pose to prosthetic treatment. The objective was to investigate the implications of different prostheses on the atrophy of posterior alveolar bone after tooth loss. A total of 457 treatment cases were retrieved from the medical documentation and information network. Baseline panoramic radiographs taken at prosthetic delivery and follow-up radiographs (≥ 3 years post-treatment) were available for analysis, with a mean follow-up duration of 6.42 ± 2.37 years. Posterior mandibular bone height in these radiographs was compared using one-way ANOVA followed by the Tukey post hoc test for statistical analysis. Sites supporting fixed prostheses commonly used in partially edentulous mandibles exhibited less bone atrophy compared to sites with clasp- or telescope-retained removable partial dentures (RPDs) (p < 0.001). Furthermore, sites with clasp-retained RPDs and telescope-retained RPDs demonstrated less bone atrophy when distal support was present (p < 0.001). In edentulous mandibles, bar-retained overdentures supported by four implants exhibited significantly less bone atrophy compared to mucosa-supported complete dentures, bar-retained overdentures supported by two implants, or overdentures retained by Locator abutments on two implants (p < 0.001). Bone atrophy in the posterior mandible should be expected to vary greatly with prosthetic designs. Long-term stability is possible with fixed partial prostheses, RPDs are less favorable in the absence of a distal support and bar-retained overdentures on four or more implants exhibited the lowest bone atrophy in fully edentulous mandibles. Not applicable – retrospective analysis.

Three-dimensional (3D) printing technology has gained popularity in producing removable partial denture (RPD) frameworks, including direct 3D printing of the metal framework and framework printing using castable resin, subsequently cast and processed. However, whether the technology is sufficiently accurate and precise to supersede traditional methods is unclear. The purpose of this in vitro study was to determine the accuracy and precision of 2 different methods in the fabrication of RPD frameworks, including 3D printing by selective laser melting (SLM) and digital light processing (DLP). Maxillary casts were digitized to design RPD frameworks. Thereby, 8 frameworks were produced for each group. The SLM group underwent a thermal finishing process after printing. In the DLP group, castable resin was printed but not cast. All frameworks were scanned to generate digital files, which were then compared with the original design using a metrology software program and manual measurements. Statistical analysis was executed using the t-test for independent specimens (α=.05) and by comparing heatmaps of the overlaid meshes. The analysis of the frameworks indicated minor deviations across all specimens. Regarding accuracy, there were no significant differences between the groups (P=.986). The SLM frameworks demonstrated greater precision, with absolute deviation values of 0.13 mm compared with 0.17 mm in the DLP group (P<.001). The findings underscored a high consistency between the 2 printing techniques, demonstrating a sufficiently advanced production process to yield predictable results. While the accuracy of both techniques was at a comparably high level and did not differ significantly, the SLM technique delivered RPDs with higher precision.

Objectives: To assess in a prospective randomized trial two phycogenic bone substitutes—biphasic calcium phosphate (BCP) versus almost pure hydroxyapatite (HA)—for their volume stability and clinical implications after sinus floor elevation (SFE).Materials and Methods: Twenty patients requiring lateral‐window SFE 6 months prior to implant surgery were randomized to a BCP or HA group. As primary outcome, the grafts were analyzed for volume stability, using four cone‐beam computed tomography scans obtained immediately/6/12/24 months after SFE. Secondary outcomes were implant survivval, success, periotest values, oral‐health‐related quality of life (OHIP‐G14), and pain (VAS).Results: Kolmogorov–Smirnov goodness‐of‐fit test revealed normal distribution of samples (p = .200). At 6/12/24 months, the augmented volumes decreased to 96/92/90% (HA) or 99/96/96% (BCP). Volume changes were significantly a factor of time (p < .001; generalized linear model with repeated measures) and reached significantly lower values in HA group (p = .018). Significant intergroup difference in volume losses was notable at 24 months (p = .021; t‐test for independent samples). Periotest values decreased from −3/−4.1 (HA/BCP) after implant placement to −6.3/−4.5 (HA/BCP) after 6 months. OHIP scores diverged at 2 months (HA: 9.5; BCP: 5.2) and largely resolved by 24 months (HA: 1.3; BCP: 1.9). VAS scores were comparable, 2.2 at 1 week after SFE being their highest mean level.Conclusions: After 2 years, both groups experienced no biological or technical complications, demonstrating a consistent healing trajectory without notable symptoms. Although no significant differences were observed in implant stability and survival, BCP demonstrated higher volume stability than HA.