Micro-morphologic changes around biophysically-stimulated titanium implants in ovariectomized rats

<p>Abstract</p> <p>Background</p> <p>Osteoporosis may present a risk factor in achievement of osseointegration because of its impact on bone remodeling properties of skeletal phsiology. The purpose of this study was to evaluate micro-morphological changes in bone around titanium implants exposed to mechanical and electrical-energy in osteoporotic rats.</p> <p>Methods</p> <p>Fifteen 12-week old sprague-dowley rats were ovariectomized to develop osteoporosis. After 8 weeks of healing period, two titanium implants were bilaterally placed in the proximal metaphyses of tibia. The animals were randomly divided into a control group and biophysically-stimulated two test groups with five animals in each group. In the first test group, a pulsed electromagnetic field (PEMF) stimulation was administrated at a 0.2 mT 4 h/day, whereas the second group received low-magnitude high-frequency mechanical vibration (MECHVIB) at 50 Hz 14 min/day. Following completion of two week treatment period, all animals were sacrificed. Bone sites including implants were sectioned, removed <it>en bloc </it>and analyzed using a microCT unit. Relative bone volume and bone micro-structural parameters were evaluated for 144 μm wide peri-implant volume of interest (VOI).</p> <p>Results</p> <p>Mean relative bone volume in the peri-implant VOI around implants PEMF and MECHVIB was significantly higher than of those in control (<it>P </it>< .05). Differences in trabecular-thickness and -separation around implants in all groups were similar (<it>P </it>> .05) while the difference in trabecular-number among test and control groups was significant in all VOIs (<it>P </it>< .05).</p> <p>Conclusion</p> <p>Biophysical stimulation remarkably enhances bone volume around titanium implants placed in osteoporotic rats. Low-magnitude high-frequency MECHVIB is more effective than PEMF on bone healing in terms of relative bone volume.</p

Peri-implant bone damage procured by piezoelectric and conventional implant site preparation: An in vitro comparison

Background: The conventional drill technique is the most commonly used for the implant site preparation of the desired diameter and length. Ultrasonic implant site preparation (UISP) can also be used to perform an implant site preparation of the desired dimensions. Methods: Implant sites were prepared in fresh bone ribs with two different implant site preparation techniques: implant surgical drills and piezoelectric tips. Samples were analyzed with scanning electron microscopy (SEM) for evaluating the peri-implant bone damage. Result: In the surgical drills group, the cortical bone surface showed several cracks and the bone vascular canals were hidden by a dense smear layer. Cancellous bone showed large irregularities and trabecular fractures. The piezoelectric group showed a clean and smooth cortical bone surface with opened bone vascular canals; the cancellous bone presented a regular morphology, and the trabecular spaces, clearly visible, were free of debris. Conclusions: Ultrasonic implant site preparation showed cleaner bone surfaces and lower bone trauma compared with the preparation using implant surgical drills

Case report: Non-invasive cyto-salivary sampling and biomarker detection via ELISA versus histopathology for diagnosing oral potentially malignant disorders - Insights from a case-control study

Oral leukoplakia is classified among oral potentially malignant disorders (OPMDs) by the World Health Organization (WHO). The visual oral examination (VOE) is the most used method for identifying lesions in their early stages. Given that the diagnosis of oral cancer is often late, there is an urgent need for early detection and examination of oral lesions. Surgical biopsy represents the gold standard as a diagnostic method, but because it is invasive, it cannot be repeated for periodic checks. We report the case of a lesion on the buccal mucosa of a 65-year-old male patient with a malignant appearance. The patient underwent a novel non-invasive cyto-salivary sampling and ELISA immunoassay for tumor biomarker detection and biopsy with histopathological analysis. The rapid ELISA test results excluded signs of malignancy, providing valuable insights into the lesion’s immunophenotypic profile, which were consistent with the histopathological examination findings. This case report highlights the clinical and histopathological characteristics of a lesion with the aspect of Proliferative Verrucous Leukoplakia (PVL), emphasizing its challenging diagnosis and management. The integration of non-invasive cytobrush sampling with biomarker analysis proved valuable in detecting specific tumor biomarkers, potentially indicating ongoing tumor transformation. Monitoring these markers over time could enhance early detection and management strategies, thereby improving patient outcomes. This approach underscores the utility of non-invasive techniques in phenotyping oral lesions and supporting clinical decision-making in oral medicine

Debris production in bovine bone during implant site preparation. A comparative in vitro study: ultrasonic and drilling procedures

The aim of this study was to compare the size and shape of bone fragments produced by the ultrasonic and drilling procedures in implant site preparation. Six pieces of rib selected as experimental animal model of 15 cm in length and at least 13 mm of thickness were used. The samples were treated and divided into 2 groups as follows: group A (GA) ultrasonic implant site preparation technique; group B (GB) traditional surgical drill technique. Ultrasonic implant site preparation (GA) was carried out using a sequence of progressive diameter (1.00 mm, 2.00 mm and 3.00 mm) conical inserts at a depth of 10 mm. Standard drill implant site procedure (GB) was carried out with a sequence of 1.00 mm, 2.00 mm, and 3.00 mm cylindrical twist drills, for preparing an implant site at a depth of 10 mm. From each group bone fragments (0.1 gr) were collected from both cortical and cancellous bone preparation and their dimensions were evaluated by optic microscope analysis. The bone debris dimensions procured by cortical bone of Group A and Group B were, respectively, 0.14&times;0.16 mm (&plusmn;0.13) and 1.15 &times;0.92 mm (&plusmn;0.68). The bone debris dimensions procured by cancellous bone of Group A and Group B were, respectively, 0.15&times;0.10 mm (&plusmn;0.10) and 1.98&times;1.27 mm (&plusmn;0.94). Ultrasonic implant site preparation technique was able to micronize bone and to remove all debris with cooling system. Surgical drills tend to fracture bone, creating a weaker structure and fragments of larger size, which remain in considerable quantity over bone walls during site preparation. Within the limits of the present study, the ultrasonic implant preparation was able to produce reduced bone sediments and a clear bed implant favoring osseointegration

Bone loss around immediately loaded transitional implants: histologic and microcomputed tomographic analysis – a case report

Immediate loading of dental implants can significantly decrease treatment time and thus result in an increase in patient acceptance. However, there is still a need to investigate whether an implant in which primary stability is achieved can be immediately loaded without the formation of connective fibrous tissue at the interface. Three transitional implants were placed in an edentulous mandible: two implants loaded immediately and one left unloaded. All transitional implants were retrieved after a period of 12 weeks to perform qualitative and quantitative analysis of the peri-implant tissue and bone-implant interface. Bone biopsy specimens containing the transitional implant were analyzed using microcomputed tomography (micro- CT). Subsequently, the same samples were analyzed using standard undecalcified histology. Micro-CT analysis showed that bone tissue was slightly detached from the surface of the loaded implant. Histology demonstrated the presence of a soft tissue layer inside the socket. Morphometric values of total bone volume, boneimplant contact, and bone connectivity were higher for the unloaded implant, which appeared to be covered by an almost continuous layer of bone. Micro-CT evaluation of some morphometric parameters and histologic results pertaining to small-diameter transitional implants showed that uncontrolled loading may produce untoward effects on peri-implant bone healing