Vicente Vanaclocha

Trigeminal neuralgia (TN) is a debilitating craniofacial pain disorder that often necessitates surgical intervention when medical therapy fails. This study evaluates the impact of two Teflon implantation techniques - pledget interposition and shredded Teflon - on clinical outcomes following microvascular decompression (MVD). A retrospective analysis was conducted on 121 patients with classical trigeminal neuralgia (TN) who underwent microvascular decompression (MVD) between 2001 and 2020. Patients were grouped based on the Teflon technique used: pledget interposition (n = 55) or shredded Teflon (n = 66). Outcomes were assessed using the Barrow Neurological Institute (BNI) pain scale, Modified Rankin Scale (mRS), and postoperative MRI. Statistical comparisons included Fisher's exact test, chi-square test, and t-tests. Shredded Teflon was associated with significantly lower recurrence (4.54% vs. 16.36%) and complication rates (9.09% vs. 14.55%) compared to pledget interposition. Reoperation was required in 12.72% of pledget cases, primarily due to implant displacement and arachnoid adhesions; no reoperations were needed in the shredded group. MRI-confirmed recurrent neurovascular compression correlated with clinical recurrence (p = 0.033). Patient satisfaction was significantly higher in the shredded group (87.87% vs. 69.09%, p = 0.001). MVD using shredded Teflon yields superior long-term outcomes with fewer complications and recurrences compared to pledget interposition. Avoiding direct nerve contact and minimizing implant volume may reduce inflammatory risks. Postoperative MRI is crucial for detecting recurrence and guiding subsequent interventions.

Unmodified Ti6Al4V can osseointegrate, but sometimes this capacity needs to be improved. This study aimed to see how much porosity improves osseointegration in a Ti6Al4V implant. Three types of Ti6Al4V cylindrical-shaped implants (13.00 mm length × 5.00 mm diameter) were evaluated: solid sandblasted acid-etched, sintered, and porous 3D-printed (681.00 µm average pore size). Fifteen 20-week-old nullipara female parasite-free New Zealand California white rabbits were used, employing the femoral condyle defect model and undertaking µ-CT analysis and pull-out testing eight weeks later. On µ-CT densitometric analysis, the solid sandblasted rod showed the highest new bone growth around the implant. Bone growth was higher inside the implants for the porous 3D-printed (54.00 ± 5.00 mm³) than for the sintered (1.00 ± 0.05 mm³) and zero for the sandblasted implants. In the pull-out test, there were no statistically significant differences in the ANOVA analysis between the sintered (900.00 N ± 310.00 N) and porous 3D-printed (700.00 N ± 220.00 N) implants. Such differences did exist between the sandblasted material (220.00 N ± 50.00 N) and the two other materials (sintered p 0.002, porous p 0.034). The porous 3D-printed and sintered implant pull-out strength were significantly better than that of the solid rod sandblasted implant. Still, there were no statistically significant differences between the first two.

Primary dental implant stability is critical to enable osseointegration. We assessed the primary stability of our newly designed dental implant. We used the calf rib bone animal model. Our implant has an outside tapered screw with two inside barrettes that deploy with a second screw situated at the implant’s crown. We used ten calf ribs with III/IV bone density and inserted ten implants per rib. We deployed the barrettes in the calf rib’s transversal direction to support against the nearby cortical bone. We measured the primary implant’s stability with resonance frequency analysis and collected the Implant Stability Quota (ISQ) in the transverse and longitudinal calf rib planes before (PRE) and after (POS) deploying the barrette. The mean ISQ was PRE 84.00 ± 3.56 and POS 84.73 ± 4.53 (p = 0.84) in the longitudinal plane and PRE 81.80 ± 2.74 and POS 83.53 ± 4.53 (0.27) in the transverse plane. The barrettes’ insertion increases our dental implant primary stability by 11% in the transverse plane and 2% in the longitudinal plane. Our dental implant ISQ values are in the higher range than those reported in the literature and reflect high primary stability after insertion. The barrette deployment improves the dental implant’s primary stability, particularly in the direction in which it deploys (transverse plane).

New subperiosteal dental implants were designed to offer new options to edentulous patients with severe bone resorption for whom endosseous dental implants are not advisable. In our study, we aimed to design and manufacture subperiosteal dental implants with a minimum volume to facilitate surgical maneuvers and metal coverage by mucosa while ensuring maximal long-term implant strength and functionality. With cone-beam CT-scan data obtained from an edentulous patient, a maxilla and mandible recreation were created, and subperiosteal implants were designed and analyzed with FEA (250 MPa infinite-life limit stress). We redesigned them until they stood the infinite-life limit loads mentioned above. Then, they were manufactured with Ti6Al4V alloy and laser-powder bed fusion technology. All implants withstood mechanical tests (450 N static and 150 N loads for five-million cycle 150 N fatigue tests) with no failures. The first design resulted in maxillary and mandibular implant failures. Through the redesign process, the implant volume was reduced, and the number and placement of bone fixation screws were optimized while maintaining resistance to chewing. Once manufactured, these new implants withstood the loads mentioned above without failure. Our subperiosteal dental implants are an option for edentulous patients with severe maxilla and mandibular bone resorption. Manufactured with Ti6Al4V alloy and laser-powder bed fusion technology, they withstood the above-mentioned mechanical tests without failure.

Anterior longitudinal ligament and annulus fibrosus removal in total disc replacement induces excessive spinal mobility with zygapophyseal joint overload and osteoarthritic changes causing chronic back pain. To control disc arthroplasty-induced hypermobility with a Kevlar® band. A 3 × 3 cm Kevlar® band implanted in twelve human lumbar cadaveric spines substituted the anterior longitudinal ligament and annulus in disc arthroplasty. Biomechanical studies compared the intact spine, after discectomy, post-disc arthroplasty, and with the Kevlar® band inserted. The Kevlar® band recovered the extension and axial rotation movement ranges without regaining the intact status. Improvement was moderate in lateral bending. The Instantaneous Axis of Rotation improved the discectomy and total disc prosthesis conditions without recovering the initial state. The disc above the operated one also showed increased mobility, particularly in extension and axial rotation, improved by Kevlar® band insertion without recovering the intact spine values. The Kevlar® band improves excess mobility ranges induced by anterior longitudinal ligament and anterior annulus removal in disc arthroplasty in the operated and supra-adjacent discs without recovering the baseline status.