1,720,974 research outputs found
Surface microstructure of dental implants before and after insertion: an in vitro study by means of scanning probe microscopy
No full textBone loss around immediately loaded transitional implants: histologic and microcomputed tomographic analysis – a case report
No full textImmediate 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
Implant primary stability determined by resonance frequency analysis: correlation with insertion torque, histologic bone volume, and torsional stability at 6 weeks.
No full textImplant Primary stability detrminated by resonance frequency analysis: correlation with insertion torque, histologic bone volume and torsional stability at 6 week
No full textPeri-implant bone damage procured by piezoelectric and conventional implant site preparation: An in vitro comparison
No full textBackground: 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
No full textOral 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
Micro-scale surface patterning of titanium dental implants by anodization in the presence of modifying salts
No full textThe bone-implant interface influences peri-implant bone healing and osseointegration. Among various nano-engineering techniques used for titanium surface modification, anodization is a simple, high-throughput and low-cost process, resulting in a nanoporous oxide coating which can promote osseointegration and impart antimicrobial and immunomodulatory properties. We anodized rounded tip dental implants of commercial grade titanium in aqueous phosphoric acid modified with calcium and potassium acetate, and characterized the resulting surface morphology and composition with scanning electron microscopy and energy dispersive spectrometry. The appearance of nanopores on these implants confirmed successful nanoscale morphology modification. Additionally, the metal cations of the used salts were incorporated into the porous coating together with phosphate, which can be convenient for osseointegration. The proposed method for surface nanostructuring of titanium alloy could allow for fabrication of dental implants with improved biocompatibility in the next stage of research
Microcomputed tomographic analysis of bone reaction at insertion of orthodontic mini-implants in sheep.
No full textPURPOSE: To evaluate the effects on bone of forced insertion of self-tapping orthodontic mini-implants and thus obtain biomechanical data to develop insertion protocols and optimize drills for implant site preparation.
MATERIALS AND METHODS: After implant site preparation, 39 orthodontic mini-implants (OMI), 1.6 x 7.5 mm each, were inserted into the hard bone of sheep mandible; 24 were placed with a 1-mm bone drill and 15 were placed with a standard-diameter (1.2-mm) drill. Removal torque was measured immediately (group A) and 8 weeks after insertion (group B). Eight OMIs (group C) were removed from the mandible in block sections of appropriate size for microcomputed tomographic morphometric and morphologic analyses.
RESULTS: All OMIs were placed without complications, with mean insertion torque of 17.625 (± 1.71) Ncm (test groups) and 17.70 (± 1.41) (control groups) and were stable at reentry. Group A implants showed a reduction in removal torque of 5.66%, while in group B, removal torque was reduced by 43.25%. In the control groups (ie, OMIs placed with a 1.2-mm drill), removal torque immediately after placement was reduced by 5.64%, and 8 weeks after insertion, removal torque had declined by 18.2%. Microcomputed tomographic bone morphometric analysis for both test and control groups showed that bone-implant contact was lower than expected in cortical bone 8 weeks after insertion. Morphologic analysis revealed cavities in the cortical bone close to the surface and microcalli in soft bone. Cavities in the cortical bone may have been caused by bone trauma during insertion.
CONCLUSIONS: The use of a narrow drill for site preparation increased orthodontic screw insertion torque, but it also damaged the bone and decreased removal torque. Standard histologic examination may clarify whether cavities in hard bone are actually signs of bone resorption that results from the activation of remodeling
Microstructure of Titanium-Cement-Lithium Disilicate Interface in CAD-CAM Dental Implant Crowns: A Three-Dimensional Profilometric Analysis
No full textAbstract
Background
Peri-implantitis is an infection of the implant surface caused by adhesion of bacteria that generate bone resorption and sometimes even consequent implant loss. Both screw-retained and cemented fixed implants are affected.
Purpose
The purpose of this study is to investigate the morphological defects at the cemented interface between titanium abutment and ceramic crown, comparing different adhesive cements used to fill the marginal gap.
Materials and Methods
Twelve computer-aided design–computer-aided manufacturing dental crowns were cemented to titanium abutments using three different resin composite cements. Sealed margins were polished using grommets with descending diamond particle size. Three groups of four crowns each were made according to the cement used, namely RelyX Unicem (3 M ESPE), Panavia F 2.0 (Kuraray), and NX3 (Nexus Kerr). Samples were analyzed using optical inspection, three-dimensional profilometry, and image analysis, including analysis of variance.
Results
Although RelyX showed significantly lower root mean square surface roughness (4.4 ± 1.5 μm) than that of NX3 (7.0 ± 2.9 μm), it showed no significant difference with Panavia (3.7 ± 1.5 μm). The marginal gap was significantly wider in Panavia (149 ± 108 μm) as compared with NX3 (71 ± 45 μm) and Relyx (64 ± 34 μm). For all groups, homogeneous heights of both metal-cement and ceramic-cement gaps were observed. Moreover, all samples showed homogeneity of the margins and absence of instrumental bias, thus validating both procedure and materials.
Conclusions
When using the chosen polishing method, RelyX Unicem showed both low roughness and marginal width, and thus the smoothest and more continuous abutment-crown interlayer, promising a low probability of occurrence of peri-implantitis
- …
