Blood Clotting Dissolution in the Presence of a Magnetic Field and Preliminary Study with MG63 Osteoblast-like Cells-Further Developments for Guided Bone Regeneration?

BACKGROUND: The influence of a magnetic field on the activation of bone cells and remodelling of alveolar bone is known to incite bone regeneration. Guided Bone Regeneration (GBR) aims to develop biomimetic scaffolds to allow for the functioning of the barrier and the precise succession of wound healing steps, including haemostasis. The effect of a magnetic field on blood clot dissolution has not been studied yet. METHODS: We conducted a methodological study on the clot stability in the presence of a static magnetic field (SMF). Preformed whole blood (WB) clots were treated with either a broad proteolytic enzyme (trypsin) or a specific fibrinolytic agent, i.e., tissue-type plasminogen activator (t-PA). MG63 osteoblast-like cells were added to preformed WB clots to assess cell proliferation. RESULTS: After having experienced a number of clotting and dissolution protocols, we obtained clot stability exerted by SMF when tissue factor (for clotting) and t-PA + plasminogen (for fibrinolysis) were used. WB clots allowed osteoblast-like cells to survive and proliferate, however no obvious effects of the magnetic field were noted. CONCLUSIONS: Paramagnetic properties of erythrocytes may have influenced the reduction in clot dissolution. Future studies are warranted to fully exploit the combination of magnetic forces, WB clot and cells in GBR applied to orthodontics and prosthodontics.

Guided Bone Regeneration with Occlusive Titanium Barrier: A Case Report and Clinical Considerations.

The need to obtain adequate bone volumes for prosthetic rehabilitation supported by implants, using different techniques and materials, represents an urgent need in modern dentistry. We report a case regarding the management of implant-prosthetic rehabilitation of the first and second upper right molars, in which no less than 4 mm of crestal bone remained to insert two implants. Regeneration of the residual bone was previously performed using a customized titanium barrier and a filler of a blood clot with tricalcium beta phosphate. The bone gain (3 mm) was evaluated by comparing CBCT images, while the implant stability (mean 70) was assessed with the ISQ measurement. A regenerated bone sample was taken for histological analysis. Guided bone regeneration obtained with a titanium barrier and blood clot allowed for the insertion of stable implants in a mature bone without heterologous material.

The Role of Blood Clot in Guided Bone Regeneration: Biological Considerations and Clinical Applications with Titanium Foil.

In Guided Bone Regeneration (GBR) materials and techniques are essential to achieve the expected results. Thanks to their properties, blood clots induce bone healing, maturation, differentiation and organization. The preferred material to protect the clot in Guided Bone Regeneration is the titanium foil, as it can be shaped according to the bone defect. Furthermore, its exposition in the oral cavity does not impair the procedure. We report on five clinical cases in order to explain the management of blood clots in combination with titanium foil barriers in different clinical settings. Besides being the best choice to protect the clot, the titanium foil represents an excellent barrier that is useful in GBR due to its biocompatibility, handling, and mechanical strength properties. The clot alone is the best natural scaffold to obtain the ideal bone quality and avoid the persistence of not-resorbed granules of filler materials in the newly regenerated bone. Even though clot contraction still needs to be improved, as it impacts the volume of the regenerated bone, future studies in GBR should be inspired by the clot and its fundamental properties.

Implant rehabilitation in patients with oral lichen planus: an overview.

OBJECTIVES: Implant rehabilitation in oral lichen planus (OLP) is a major challenge for clinicians and patients. There is limited scientific evidence, primarily case reports and small case series. We conducted a literature review of data on the effectiveness and safety of implant rehabilitation in OLP patients. MATERIAL AND METHODS: We searched MEDLINE, Embase and Cochrane databases for articles on implant placement in OLP patients (searches from 1980 to 2011). RESULTS: Eight studies (41 OLP patients rehabilitated with 135 implants) met the inclusion criteria. Survival rate of implants was 94.8% over a mean follow-up of 56.5 months. CONCLUSIONS: There is very limited evidence on the safety and benefits of implant placement in OLP patients. Implant loss appears not to be directly related to OLP, but linked to factors such as parafunctions, poor bone quality and marginal mandibular resection. The benefits and harms of using implants in people with OLP require thorough evaluation in properly designed randomised, controlled studies. CLINICAL RELEVANCE: OLP is not an absolute contraindication for implant insertion and there is no increased risk of failure. Implants should be positioned only if mucosal signs and symptoms are in the remission phase. A careful oral hygiene and frequent follow-up are the main recommendations in OLP patients rehabilitated with implants.

Dental fragment embedded in the lower lip after facial trauma: Brief review literature and report of a case.

Upper incisors are the most frequently involved teeth in traumatic dental injuries. Soft tissues (lips and/or oral mucosa) adjacent to incisal edge can receive direct and/or indirect traumas. Laceration of the lower lip is a not rare eventuality and teeth fragments could be embedded in labial soft tissue. The reattachment of these fragments, if possible, is the elective treatment choice, thanks to the modern adhesive and restorative techniques. The authors present a case of a white Caucasian 10-year-old child, who attended the dental clinic for the treatment of both upper central incisors' crown fractures. The fragment of the left incisor was retrieved embedded in the lower lip. It was successfully surgically removed and reattached using a composite adhesive technique. A careful clinical and radiographic examination with the surgical removal of tooth fragments could prevent undesirable foreign body reaction, infection and scarring. The authors also reviewed the most relevant literature concerning tooth fragment reattachment after removal from oral soft tissues.

Candida-associated denture stomatitis

Candida albicans is a dimorphic yeast strongly gram positive able to live as normal commensal organism in theoral cavity of healthy people. It is the yeast more frequently isolated in the oral cavity. Under local and systemicfactors related to the host conditions, it becomes virulent and responsible of oral diseases known as oral candidiasis.It has been shown that the presence of denture is a predisposing factor to the onset of pathologies related toC. albicans. Clinical studies have shown that C. albicans is not only able to adhere to the mucous surfaces, but alsoto stick to the acrylic resins of the dental prostheses. Both the plaque accumulated on the denture and the poororal hygiene contribute to the virulence of Candida, offering the clinical picture of Candida-associated denturestomatitis. The therapeutic strategies currently adopted in the clinical practice to overcome these fungal infectionsprovide for the use of topical and/or systemic antifungal and topical antiseptics and disinfectants, the irradiationwith microwaves and the accurate mechanical removal of the bacterial plaque from the denture surfaces and fromthe underlying mucosa. A correct oral hygiene is important for the control of the bacterial biofilm present on thedenture and on the oral mucosa and it is the fundamental base for the prophylaxis and the therapy of the Candidaassociateddenture stomatitis (AU)

Candida-associated denture stomatitis.

Candida albicans is a dimorphic yeast strongly gram positive able to live as normal commensal organism in the oral cavity of healthy people. It is the yeast more frequently isolated in the oral cavity. Under local and systemic factors related to the host conditions, it becomes virulent and responsible of oral diseases known as oral candidiasis. It has been shown that the presence of denture is a predisposing factor to the onset of pathologies related to C. albicans. Clinical studies have shown that C. albicans is not only able to adhere to the mucous surfaces, but also to stick to the acrylic resins of the dental prostheses. Both the plaque accumulated on the denture and the poor oral hygiene contribute to the virulence of Candida, offering the clinical picture of Candida-associated denture stomatitis. The therapeutic strategies currently adopted in the clinical practice to overcome these fungal infections provide for the use of topical and/or systemic antifungal and topical antiseptics and disinfectants, the irradiation with microwaves and the accurate mechanical removal of the bacterial plaque from the denture surfaces and from the underlying mucosa. A correct oral hygiene is important for the control of the bacterial biofilm present on the denture and on the oral mucosa and it is the fundamental base for the prophylaxis and the therapy of the Candida-associated denture stomatitis.

Candida-related denture stomatitis: a pilot study of the efficacy of an amorolfine antifungal varnish.

PURPOSE: Candida albicans is a component of the normal oral microflora, but local and systemic factors can transform this commensal C albicans to a pathogen. The most frequent cause of Candida opportunistic infections (candidiasis) is dentures, especially if poorly fitting or poorly cleaned. Management of oral candidiasis depends on an accurate diagnosis, identification and elimination of predisposing factors, and, often, use of antifungal agents. The aim of this study was to examine fingernail varnish, currently used for onychomycosis therapy, to reduce the fungal colonization in prosthetic biofilms. MATERIALS AND METHODS: A varnish containing 5% amorolfine was applied once or twice a week for 6 months in six patients affected by nystatin-resistant denture-related stomatitis. In all six patients, the prostheses had previously been removed at night, and daily antimycotic topical therapy with nystatin had failed to resolve the stomatitis; after 30 days, these patients all showed persistence of candidal stomatitis. RESULTS: After 1 month, five of the six patients were negative for Candida; this situation was unchanged in the following monthly controls. Only in the patient with suspected Sjögren syndrome was oral Candida found 15 days after the last varnish application. None of the patients had any complaints about the medication. CONCLUSION: This varnish containing 5% amorolfine, applied once or twice a week for 6 months, was able to suppress the nystatin-resistant denture-related stomatitis.