Biomedical Ti–Mo Alloys with Surface Machined and Modified by Laser Beam: Biomechanical,Histological, and Histometric Analysis in Rabbits

Purpose: In vivo bone response was assessed by removal torque, hystological and histometrical analysis on a recently developed biomedical Ti‐15Mo alloy, after surface modification by laser beam irradiation, installed in the tibia of rabbits. Materials and Methods: A total of 32 wide cylindrical Ti‐15Mo dental implants were obtained (10 mm × 3.75 mm). The implants were divided into two groups: 1) control samples (Machined surface – MS) and 2) implants with their surface modified by Laser beam‐irradiation (Test samples – LS). Six implants of each surface were used for removal torque test and 10 of each surface for histological and histometrical analysis. The implants were placed in the tibial metaphyses of rabbits. Results: Average removal torque was 51.5 Ncm to MS and >90 Ncm to LS. Bone‐to‐implant‐contact percentage was significantly higher for LS implants both in the cortical and marrow regions. Conclusions: The present study demonstrated that laser treated Ti‐15Mo alloys are promising materials for biomedical application.     

Femtosecond laser-assisted implantation of corneal stroma lenticule for keratoconus

International Ophthalmology - To review recent progress, challenges, and future perspectives of stromal keratophakia for the treatment of advanced keratoconus. We systematically reviewed the...     

Immediate loading of mandibular overdentures supported by unsplinted direct laser metal-forming implants: results from a 1-year prospective study

Background: At present, only some studies have dealt with immediate loading of unsplinted implants supporting mandibular overdentures. The aim of this prospective study is to evaluate treatment outcomes of mandibular overdentures supported by four one‐piece, unsplinted, immediately loaded, direct laser metal‐forming (DLMF) implants by assessing implant survival rate, implant success, marginal bone loss, and prosthetic complications. Methods: A total of 96 one‐piece DLMF implants were inserted in the edentulous mandible of 24 patients. Four implants were placed in each edentulous mandible. Immediately after implant placement, a mandibular overdenture was connected to the implants. At 1‐year follow‐up, clinical, radiographic, and prosthetic parameters were assessed. Success criteria included absence of pain, suppuration, and implant mobility; absence of continuous peri‐implant radiolucency; and distance between the implant shoulder and the first visible bone contact <1.5 mm. Results: After a 1‐year loading time, the overall implant survival rate was 98.9%, with only one implant lost. Among the surviving 95 implants, two did not fulfill the success criteria; therefore, the implant success rate was 97.8%. The mean distance between the implant shoulder and the first visible bone contact was 0.28 ± 0.30 mm (95% confidence interval, 0.24 to 0.32). Some prosthetic complications were reported. Conclusion: Based on the present results and within the limits of this study, the immediate loading of four unsplinted DLMF implants by means of ball attachment–supported mandibular overdentures seems to represent a safe and successful procedure.     

JC virus granule cell neuronopathy and GCN–IRIS under natalizumab treatment

Progressive multifocal leukoencephalopathy is the most common clinical presentation of JC virus (JCV)‐associated central nervous system (CNS) disease and has emerged as a major safety concern in multiple sclerosis patients treated with the monoclonal antibody natalizumab. Here we report clinical, radiological, and histological findings of a case of cerebellar granule cell neuronopathy (GCN), a JCV‐associated CNS disease, so far unreported amongst patients treated with natalizumab. GCN should be considered as a JCV CNS manifestation in patients with newly developed, progressive cerebellar signs under natalizumab treatment, especially in cases where cerebellar atrophy can be visualized by magnetic resonance imaging. Ann Neurol 2013;74:622–626     

Peri-implant collagen fibers around human cone Morse connection implants under polarized light: a report of three cases

Most of the histologic studies found in the literature on the peri-implant soft tissues have been done in animals and usually have been confined to mandibular implants fitted with healing or standard abutments. Few studies have investigated human peri-implant soft tissues. Moreover, the structure and dimensions of the peri-implant soft tissues in immediately loaded implants have not been investigated in depth. Human histologic data are valuable to validate animal models. This histologic and histomorphometric study evaluated the peri-implant soft tissues around three immediately loaded implants in humans. The implants were retrieved using a trephine and treated to obtain thin, ground sections. The sulcular epithelium was composed of approximately four to five layers of parakeratinized epithelial cells and had a length of approximately 1.2 to 1.3 mm. The junctional epithelium was composed of approximately three to four layers of epithelial cells and had a length of approximately 1.0 to 1.5 mm. Connective tissue attachment had a width of between 400 and 800 μm. Peri-implant collagen fibers, in the form of bundles (1- to 5-μm thick), began at the crestal bone and were oriented perpendicular to the abutment surface until 200 μm from the surface, where they became parallel running in several directions. Collagen fibers appeared to form a three-dimensional network around the abutment. No acute or chronic inflammatory cell infiltrate was present. Collagen fibers oriented in a perpendicular manner and in direct contact with the abutment surface were not observed in any of the specimens. This differentiated network of fibers may have clinical relevance as a mechanical protection of the underlying bone. These human histologic data are extremely valuable to validate and confirm those obtained from studies performed on animal models. Moreover, immediate loading of the implants did not compromise soft tissue integration.     

Histologic and histomorphometric evaluation of an implant retrieved 8 years after insertion in a sinus augmented with anorganic bovine bone and anorganic bovine matrix associated with a cell-binding peptide: a case report

Few histologic and histomorphometric reports are present in the literature regarding the peri-implant bone response around implants inserted in sinuses grafted with different biomaterials. Anorganic bovine bone (ABB) and anorganic bovine matrix with the addition of an active cell-binding peptide (PepGen P-15) are xenogenic materials that have been reported to present biocompatibility and osteoconductivity. A monolateral sinus augmentation procedure with ABB (50%) and PepGen P-15 (50%) was performed in a 54-year-old man. Two titanium implants with a sandblasted and acid-etched surface were inserted after 6 months. After an additional 6 months, a fixed prosthetic restoration was fabricated. One implant fractured in the coronal portion after an 8-year loading period and was removed using a 5-mm trephine bur. Few particles of both grafting materials were present in the peri-implant bone. No graft material particles were found in contact with the implant surface, and bone was always interposed between the graft materials and surface. No inflammatory cell infiltrate, multinucleated giant cells, or foreign body reaction cells were found. The tissues around the implant were composed of 51.4% ± 4.8% bone, 6.2% ± 0.7% ABB particles, 2.4% ± 0.5% PepGen P-15, and 40.0% ± 7.1% marrow spaces. The bone-implant contact percentage was 78.4% ± 4.1%. A sinus augmentation procedure using ABB and PepGen P-15 produced bone formation with subsequent implant osseointegration, which was still present after 8 years of implant loading.     

CYP2B6, ABCB1 and OPRM1 profile in a stillborn affected by chronic methadone intoxication

Forensic Toxicology -