Dental implant insertion requires the preparation of the implant bed via surgical drilling. During this stage, irrigation is essential to avoid thermal damage to the surrounding bone. Surgical guides enhance the accuracy of the implant site preparation, but they mask the drilling site, hampering coolant delivery. A variety of designs are aimed at improving the coolant access to the target site. Using standard dental implant simulation software, this paper presents an in-house design and 3D printing workflow for building surgical guides that incorporate a coolant channel directed toward the entry point of the burr. The proposed design was evaluated in terms of the bone temperature elevations caused by drilling performed at 1500 rpm, under an axial load of 2 kg, and irrigation with 40 mL/min of saline solution at 25 °C. Temperature measurements were performed on porcine femoral pieces, in the middle of the cortical bone layer, at 1 mm from the edge of the osteotomy. The mean temperature rise was 3.2 °C for a cylindrical sleeve guide, 2.7 °C for a C-shaped open-sleeve guide, and 2.1 °C for the guide with an incorporated coolant channel. According to a one-way ANOVA, the differences between these means were marginally insignificant (p = 0.056). The individual values of the peak temperature change remained below the bone damage threshold (10 °C) in all cases. Remarkably, the distribution of the recorded temperatures was the narrowest for the guide with internal irrigation, suggesting that, besides the most effective cooling, it provides the most precise control of the intraosseous temperature. Further studies could test different design variants, experimental models (including live animals), and might involve computer simulations of the bone temperature field.

Air displacement plethysmography (ADP) is a widespread technique for assessing global obesity in both health and disease. The reliability of ADP has been demonstrated by studies focused on duplicate trials. The present study was purported to evaluate learning effects on the reliability of body composition assessment using the BOD POD system, the sole commercially available ADP instrument. To this end, quadruplicate trials were performed on a group of 105 subjects (51 women and 54 men). We estimated measurement error from pairs of consecutive trials—(1,2), (2,3), and (3,4)—to test the hypothesis that early measurements are subject to larger errors. Indeed, statistical analysis revealed that measures of reliability inferred from the first two trials were inferior to those computed for the other pairs of contiguous trials: for percent body fat (%BF), the standard error of measurement (SEM) was 1.04% for pair (1,2), 0.71% for pair (2,3), and 0.66% for pair (3,4); the two-way random effects model intraclass correlation coefficient (ICC) was 0.991 for pair (1,2), and 0.996 for pairs (2,3) and (3,4). Our findings suggest that, at least for novice subjects, the first ADP test should be regarded as a practice trial. When the remaining trials were pooled together, the reliability indices of single ADP tests were the following: ICC = 0.996, SEM = 0.70%, and minimum detectable change (MDC) = 1.93% for %BF, and ICC = 0.999, SEM = 0.49 kg, and MDC = 1.35 kg for fat-free mass (FFM). Thus, the present study pleads for eliminating learning effects to further increase the reliability of ADP.

Dental implant bed preparation involves surgical drilling. Heat generated in this process can cause a temperature elevation beyond the bone damage limit (10 °C), affecting the osseointegration of the implant. Surgical templates ensure accurate implant placement, but they limit the access of the irrigation fluid. This study evaluated the hypothesis that surgical guides with internal cooling prevent bone heating more effectively than classical guides. To eliminate biological variability, this study was conducted on artificial bone pieces that mimic the bone density of the human mandible. We created a surgical template that incorporated four pairs of guides—one classical (CLA) and one with internal cooling (INT) in each pair. For each specimen, we randomly selected the type of surgical guide to start with and performed four osteotomies with a 2.7 mm-diameter drill; then, we widened each hole with a 3.3 mm drill and finalized it with a 3.7 mm drill. The temperature was recorded by thermocouples placed at 0.8 mm from the prospective edge of the final osteotomy. In 168 measurements (12 osteotomies on 14 specimens) conducted for each type of surgical guide, the mean temperature rise was 7.2 ± 4.9 °C (mean ± standard deviation) for CLA and 5.0 ± 3.8 °C for INT. The mean differences between temperature elevations were 1.5 °C, 2.1 °C, and 3.0 °C for the first, second, and third drill, and they were statistically significant: the p-values of Student’s t-test were 0.004, 0.01, and 0.001, respectively. Although the mean temperatures remained safe, temperature rises exceeded 10 °C in 23.8% (9.5%) of the osteotomies performed in the presence of CLA (INT). Taken together, our results suggest that surgical guides with internal cooling ensure a significant drop in the temperature rise caused by implant site drilling.

Neuromuscular electrical stimulation (NMES) is useful for muscle strengthening and for motor restoration of stroke patients. Using a portable ultrasound instrument, we developed an M-mode imaging protocol to visualize contractions elicited by NMES in the quadriceps muscle group. To quantify muscle activation, we performed digital image processing based on the Teager–Kaiser energy operator. The proposed method was applied for 35 voluntary patients (18 women and 17 men), of 63.8 ± 14.1 years and body mass index (BMI) 30.2 ± 6.70 kg/m² (mean ± standard deviation). Biphasic, rectangular electric pulses of 350 µs duration were applied at two frequencies (60 Hz and 120 Hz), and ultrasound was used to assess the sensory threshold (ST) and motor threshold (MT) amplitude of the NMES signal. The MT was 23.4 ± 4.94 mA, whereas the MT to ST ratio was 2.69 ± 0.57. Linear regression analysis revealed that MT correlates poorly with body mass index (R² = 0.004) or with the thickness of the subcutaneous adipose tissue layer that covers the treated muscle (R² = 0.013). Our work suggests that ultrasound is suitable to visualize neuromuscular reactivity during electrotherapy. The proposed method can be used in the clinic, enabling the physiotherapist to establish personalized treatment parameters.

Background/Objectives: The All-on-4 technique is a minimally invasive approach for full-arch oral rehabilitation. In cases of anterior bone resorption, the classic All-on-4 configuration may be limited by insufficient bone for axial implant insertion. An effective alternative is the “M” configuration, where all four implants are inserted at approximately 30°. This report presents a clinical case of full-arch rehabilitation using personalized surgical guides with internal cooling, designed to optimize irrigation and prevent thermal bone damage. Methods: A 57-year-old female patient underwent digital planning and flapless guided implant surgery. At the maxilla, four DENTIS SQ implants were inserted in an “M”-shaped configuration (4 × 10 mm anterior, 4 × 14 mm posterior). Before insertion, implant beds were prepared using surgical templates with internal irrigation channels. At the mandible, four posterior implants (4 × 8 mm) were placed using dentally supported guides with internal cooling. The surgical guides were designed using Implastation and Blue Sky Plan, 3D-printed in biocompatible resin and sterilized before use. We performed the osteotomies under controlled irrigation with continuous saline flow through the integrated cooling channels. Results: The guides ensured accurate implant positioning. We did not observe intraoperative complications, and all implants achieved primary stability above 35 N·cm. Postoperative healing was uneventful, with minimal edema and no mucosal dehiscence. These indirect clinical indicators suggest that the guide also ensured effective cooling. Radiographic follow-up confirmed correct 3D positioning and intimate bone-implant contact. Conclusions: This case study shows that personalized surgical guides with integrated coolant channels may provide a safe and precise solution for flapless All-on-4 “M” rehabilitations, reducing thermal risks and enhancing surgical accuracy.