Past, Present and Future of Prosthesis: 2020 Upgrade

The scientific journal Prosthesis (ISSN 2673-1592) had its first issue published in 2019 thanks to the publisher, MDPI [...

Fem and Von Mises analysis of OSSTEM ® dental implant structural components: evaluation of different direction dynamic loads

Abstract PURPOSE: The objective of this investigation is to study prosthodontics and internal components resistance to the masticatory stress and considering different force directions by using Finite Element Method analysis (FEM). The structural materials of the components are usually Titanium alloy grade 4 or 5 and thus, guarantee the integration of the fixture in the bone due to the osteointegration phenomena. Even if the long-term dental implant survival rate is easy to be obtained and confirmed by numerous researches, the related clinical success, due to the alteration of the mechanical and prosthodontics components is still controversial. METHODS: By applying engineering systems of investigations like FEM and Von Mises analyses, it has been investigated how dental implant material was held against the masticatory strength during the dynamic masticatory cycles. A three-dimensional system involved fixture, abutment and the connection screws, which were created and analyzed. The elastic features of the materials used in the study were taken from recent literature data. RESULTS: Data revealed a different response for both types of devices, although implant neck and dental abutment showed better results for all conditions of loading while the abutment screw represented aweak point of the system. CONCLUSION: The data of this virtual model showed all the features of different prosthetic retention systems under the masticatory load. Clinicians should find better prosthetic balance in order to better distribute the stress over the component and to guarantee patients' clinical long-term results

Oral health-related quality of life in partially edentulous patients before and after implant therapy: a 2-year longitudinal study

The aim of this study was to measure the Oral Health-Related Quality of Life (OHRQoL) before and after a prosthodontic implant therapy so to determine the physical and psychological impact of implant-supported fixed partial dentures (IFPD) rehabilitation among edentulous patients. Methods. 50 partially edentulous patients aged 40-70 years, treated with IFPD, completed the OHRQoL questionnaire before the implant surgery (Time 0) and 2 years after their whole implant-prosthetic rehabilitation (Time 1). The questionnaire was proposed in a short version of Oral Health Impact Profile (OHIP-14, range 0-56) and analyzed through the ‘additive method’. We evaluated statistical mean, standard deviation, median, variance and mode of all OHIP-14 domains and the statistical significance about oral changes at Time 0 and Time 1 using the Chi-square test (p-values 0.05). Patients with I and IV Kennedy’s class edentulism showed better improvement (p < 0.05). Preoperative and post-treatment assessments of OHRQoL exhibited significant differences. The IFPD treatment had a positive effect on the OHRQoL, which improved better in patients with I and IV Kennedy’s edentulous class

Atomic force microscopy of bacteria from periodontal subgingival biofilm: Preliminary study results

OBJECTIVE: Atomic force microscope (AFM) is a technology that allows analysis of the nanoscale morphology of bacteria within biofilm and provides details that may be better useful for understanding the role of bacterial interactions in the periodontal disease. MATERIAL AND METHODS: Five patients with periodontal ≥5 mm pockets diagnosed as generalized periodontitis and five patients with slight gingivitis were selected for the investigation. Bacteria biofilms were collected and morphologically investigated by AFM application. RESULTS: The investigation revealed how periodontitis bacteria are characterized by specific morphologic features of the cell wall. The major representative species of bacteria causing periodontal diseases have been reproduced by a three-dimensional reconstruction showing the bacteria surface details. CONCLUSIONS: The presence of complex glycocalyx structures, bacteriophage-like vesicles, spirochetes (classic and cystic morphology) and bacterial co-aggregation has been identified by the AFM analysis. The results suggest that AFM is a reliable technique for studying bacterial morphology and for examining microbial interactions in dental plaque

FEM and Von Mises analysis on prosthetic crowns structural elements: evaluation of different applied materials

The aim of this paper is to underline the mechanical properties of dental single crown prosthodontics materials in order to differentiate the possibility of using each material for typical clinical condition and masticatory load. Objective of the investigation is to highlight the stress distribution over different common dental crowns by using computer-aided design software and a three-dimensional virtual model. By using engineering systems of analyses like FEM and Von Mises investigations it has been highlighted the strength over simulated lower first premolar crowns made by chrome cobalt alloy, golden alloy, dental resin, and zirconia. The prosthodontics crown models have been created and put on simulated chewing stresses. The three-dimensional models were subjected to axial and oblique forces and both guaranteed expected results over simulated masticatory cycle. Dental resin presented the low value of fracture while high values have been recorded for the metal alloy and zirconia. Clinicians should choose the better prosthetic solution for the teeth they want to restore and replace. Both prosthetic dental crowns offer long-term success if applied following the manufacture guide limitations and suggestions

Histomorphometric Evaluation of Anorganic Bovine Bone Coverage to Reduce Autogenous Grafts Resorption: Preliminary Results

Physiologic resorption due to remodeling processes affects autogenous corticocancellous grafts in the treatment of atrophic jawbone alveolar ridges. Such a situation in the past made overgrafting of the recipient site mandatory to get enough bone support to dental implants in order to perform a prosthetic rehabilitation. Anorganic bovine bone, conventionally used to treat alveolar bone deficiencies in implant surgery, showed a high osteoconductive property thanks to its micro and macrostructure very similar to that of human hydroxyapatite. An original technique provides for the application of a thin layer of anorganic bovine bone granules and a collagen membrane on the top of the corticocancellous onlay bone grafts to reduce in a remarkable way the graft resorption due to remodeling. The results of a clinical prospective study and a histomorphometric analysis done on autogenous grafts harvested from the iliac crest showed that the proposed technique is able to maintain the original bone volume of the corticocancellous blocks

Intraoperative sonography for nonpalpable breast lesions: Additional indications for a consolidate technique.

This prospective study evaluated the intraoperative ultrasound scan (IUSS) for nonpalpable breast lesions' detection. A total of 108 consecutive female patients underwent surgery using IUSS: Frozen sections demonstrated clear margins in 95.5% of neoplastic patients. Only four (4.5%) patients underwent local re-excision in the same operation. IUSS demonstrated to be quick, accurate, useful, effective, and safe for the intraoperative management of neoplastic nonpalpable breast lesions when performed by a surgeon who has undergone US training, particularly for people in whom alternative approaches can show some limitations due to contraindications or because of scheduling constraints, costs, and patient discomfort

Porphyromonas gingivalis, Periodontal and Systemic Implications: A Systematic Review

In recent scientific literature, oral infections and systemic manifestations, or correlations between oral health and systemic diseases are a topic of discussion. Porphyromonas gingivalis is one of the bacteria implicated in the biofilm formation of bacterial plaque, and plays an important role in the progression of periodontal disease. In this systematic review authors have evaluated the literature of the last 10 years on P. gingivalis and all the systemic implications proven. This study therefore evaluates all the districts of the organism in which this bacterium may have implications. From the results it emerges that P. gingivalis has implications in the onset of different systemic pathologies, including rheumatoid arthritis, cardiovascular pathologies, and neurodegenerative pathologies. Surely, understanding the mechanisms of diffusion of this bacterium, it would be possible to prevent a series of pathologies. Thus, putting the dentist clinician at the center of prevention for these diseases

Protein-Signaled Guided Bone Regeneration Using Titanium Mesh and Rh-BMP2 in Oral Surgery: A Case Report Involving Left Mandibular Reconstruction after Tumor Resection

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is an osteoinductive protein approved for use in oral and maxillofacial defect reconstruction. Growth factors act as mediators of cellular growth on morphogenesis and mythogenesis phases. Utilized as recombinant proteins, these growth factors need the presence of local target cells capable of obtaining the required results. This cell population may be present at the wound site or added to scaffolding material before implantation at the surgical site