Is titanium–zirconium alloy a better alternative to pure titanium for oral implant? Composition,mechanical properties,and microstructure analysis

IntroductionTitanium (Ti) is widely accepted as a biomaterial for orthopaedic and dental implants, primarily due to its capacity to integrate directly into the bone and its superior corrosion resistance. It has been suggested that titanium–zirconium alloy (TiZr), with 13–17% of zirconium, has better mechanical properties than pure Ti, but there are very few published studies assessing the suitability of TiZr for high-load- bearing implants. This study aimed to compare the mechanical properties and microstructures of TiZr and commercially pure titanium (Ti).MethodologyPure Ti and TiZr alloy discs were prepared and subjected to characterisation by nanoindentation, electron dispersive spectroscopy (EDS), X-ray diffraction (XRD), and electron backscatter diffraction (EBSD).ResultsThe TiZr alloy was found to have significantly lower elastic modulus value (p < 0.0001) and greater hardness than Ti (p < 0.05). The EDS results confirmed the presence of Zr (13–17%) in the TiZr alloy, with XRD and EBSD images showing microstructure with the alpha phase similar to commercially available Ti.ConclusionThe lower elastic modulus, higher hardness, presence of alpha phase, and the finer grain size of the TiZr alloy make it more suitable for high-load-bearing implants compared to commercially available Ti and is likely to encourage a positive biological response.     

Is zirconia a viable alternative to titanium for oral implant? A critical review

Purpose

Titanium based implant systems, though considered as the gold standard for rehabilitation of edentulous spaces, have been criticized for many inherent flaws. The onset of hypersensitivity reactions, biocompatibility issues, and an unaesthetic gray hue have raised demands for more aesthetic and tissue compatible material for implant fabrication. Zirconia is emerging as a promising alternative to conventional Titanium based implant systems for oral rehabilitation with superior biological, aesthetics, mechanical and optical properties. This review aims to critically analyze and review the credibility of Zirconia implants as an alternative to Titanium for prosthetic rehabilitation.

Is early diagnosis of oral cancer a feasible objective? Who is to blame for diagnostic delay?

Oral Diseases (2010) 16 , 333–342 Worldwide, oral cancer has one of the lowest survival rates and poor prognosis remains unaffected despite recent therapeutic advances. Reducing diagnostic delay to achieve earlier detection is a cornerstone to improve survival. Thus, intervention strategies to minimize diagnostic delays resulting from patient factors and to identify groups at risk in different geographical areas seem to be necessary. The identification of a ‘scheduling delay’ in oral cancer justifies the introduction of additional educational interventions aimed at the whole health care team at dental and medical practices. The access to and the kind of healthcare system in a particular country are also relevant in this context, particularly the referral system. The design of a simple, clear, fail‐safe, fast‐track referral scheme for those suspected with cancer may diminish greatly the length of the delay. Moreover, there is a need for future investigations, which are methodologically adequate, that consider cultural and geographical aspects and use patient survival as the final outcome, that are able to recognize the agents/factors responsible for diagnostic delay by patients as well as healthcare providers and those attributable to the healthcare systems.     

Which surface properties enhance bone response to implants? Comparison of oxidized magnesium, TiUnite, and Osseotite implant surfaces

PURPOSE: This study compared the speed and strength of osseointegration and osteoconductivity between an oxidized experimental magnesium (Mg) implant, an oxidized commercially available TiUnite implant, and a dual acid-etched surface Osseotite implant. The aim was to investigate which surface properties enhance bone response to implants, and thereby to test a biochemical bonding theory. MATERIALS AND METHODS: A total of 60 screw implants (20 of each design) were inserted through 1 cortex into the tibiae of 10 rabbits. Surface chemistry, oxide thickness, morphology, crystal structure, and surface roughness were evaluated. After healing times of 3 and 6 weeks, all bone implants were unscrewed with removal torque (RTQ) devices, and the bone specimens were subjected to histomorphometry. RESULTS: RTQ values for Mg, TiUnite, and Osseotite implants were 27.1, 21.3, and 15.4 Ncm, with new bone formation values of 29%, 18%, and 15%, respectively, at 3 weeks. At 6 weeks the RTQ values were 37.5, 36.4, and 21.5 Ncm, with new bone formation values of 39%, 31%, and 26%, respectively. Discussion: Mg implants demonstrated significantly greater RTQ values (P = .008 and P = .0001) and more new bone formation (P = .031 and P = .030) than Osseotite at 3 and 6 weeks, respectively. Mg implants also showed higher RTQ values at 3 weeks and new bone formation at 6 weeks than TiUnite, but neither were significant (P > .05). TiUnite showed significantly higher RTQ values than Osseotite at 6 weeks (P = .001), but was not significant at 3 weeks (P > .05). Osseointegration rate (deltaRTQ/deltaweeks) was significantly faster for Mg (P = .011) and TiUnite (P = .001) implants between 3 and 6 weeks of healing time, but was not significant for Osseotite. CONCLUSIONS: The results indicate that surface chemistry facilitated more rapid and stronger osseointegration of the Mg implants despite their minimal roughness compared to the moderately roughened TiUnite. This suggests potential advantages of Mg implants for reducing high implant failure rates in the early postimplantation stage and in compromised bone, making it possible to shorten bone healing time from surgery to functional loading, and enhancing the possibility of immediate/early loading.     

Visualization and quantification of tongue movement during articulation: Is ultrasound a valid alternative to magnetic resonance imaging?

Background

Quality of life in tumour patients following combined ablative and reconstructive head and neck surgery varies significantly. This is at least partially due to differences in speech and swallowing function. A tool to objectively evaluate articulation by magnetic resonance imaging (MRI) has now been tested alongside ultrasound examination.

Prosthodontics and the patient: what is oral rehabilitation need? Conceptual analysis of need and demand for prosthodontic treatment. Part 1: a conceptual analysis

PURPOSE: The concepts of need and demand are central in studies on dental care. In the literature, a normative definition is often used, but it pays little attention to the individual's personal comfort and quality of life. Need and demand for prosthodontic services are difficult to measure, as prosthodontic treatment is highly individual and not closely related to edentulousness. Need, however defined, does not always lead to demand for treatment, depending on a variety of factors. MATERIALS AND METHODS: The present article is part of a larger study in which the intention is to evaluate need and demand for prosthodontic treatment among the participants in a 1989 and 1999 longitudinal study of a population sample. As the first step, this article reports a conceptual analysis of the need concept from the literature. RESULTS: Need is stated as socially established in the interaction between patient and clinician. It makes demand dependent on available treatment options from the care provider and society. In the prosthetic treatment decision-making process, the emancipatory perspective with the patient-clinician dialogue is of utmost importance to achieve an optimal treatment result. CONCLUSION: The professional attitude toward need must be that there is no true objective or subjective need. Need is established only in a communicative dialogue with mutual respect between the professional and the patient.     

Proposal 3: Is a coordinated and effective approach to work force planning, education, and research possible? Part II: The interdependence of research, education and the oral health work force

Undoubtedly, to achieve the goals set for oral health in New Zealand, representative leadership is essential for effective coordination of work force planning, education, and research. It is to be hoped that, from discussion and debate, this Forum will be able to make suggestions or recommendations for a structure that can be developed to allow the appropriate representation and leadership to drive research and work force planning for the provision of oral health care in New Zealand.     

Effects of a fluoride etchant and a phosphate primer on bonding of veneering composite to Ti–6Al–4V alloy for CAD/CAM restorations

PurposeTitanium abutments and superstructures are commonly veneered or covered with esthetic materials. The present investigation was carried out to evaluate the effects of an experimental surface treatment using etchant and primer on bond strength between a resin composite and Ti–6Al–4V alloy.MethodsDisk-shaped Ti–6Al–4V alloy was machine milled, the surface was air abraded with alumina, and the alloy was chemically etched with 5wt% ammonium hydrogen fluoride (F-etch) for 30 s. A phosphate primer (MDP-primer) was applied to the bonding area, and then a resin composite, with or without milled-fiber resin composite (FRC), was veneered on the specimen. Shear bond strengths were determined after thermocycling for 20,000 cycles. Bond strength data were analyzed by means of ANOVA and a multiple comparison test (α = 0.05). The surface of Ti–6Al–4V alloy was observed using a scanning electron microscope before and after the etching procedure.ResultsNo-FRC/F-etch/MDP-primer exhibited the highest bond strength (28.2 MPa), followed by No-FRC/No-etching/MDP-primer (24.2 MPa), FRC/F-etch/MDP-primer (19.9 MPa), FRC/No-etching/MDP-primer (17.8 MPa), No-FRC/No-etching/No-primer (13.6 MPa), while FRC/No-etching/No-primer (2.5 MPa) resulted in the lowest value. Microphotographs showed that numerous micro and nano pits were created on the Ti–6Al–4V alloy surface modified with F-etch.ConclusionsThe bond strength between Ti–6Al–4V alloy and the veneering resin composite was the highest when the alloy surface was modified with alumina blasting, fluoride etchant, and phosphate primer successively.     

Multiple correspondence analysis as a strategy to explore the association between categories of qualitative variables related to oral–maxillofacial trauma and violent crimes at the community level

The main objective of this study was to show the applicability of multiple correspondence analysis (MCA) in the detection and representation of underlying structures in large datasets used to investigate oral–maxillofacial lesions. A cross-sectional study was conducted involving the analysis of the medical–forensic and social records of 992 people who experienced oral–maxillofacial trauma resulting from non-fatal violent crimes that occurred in the community. Based on the MCA results, two distinct victim profiles were identified. The first profile was characterized by adult men, victims of instruments of violence (such as firearms, knives, or mixed aggression), resulting in severe trauma, mainly affecting the upper or middle third of the face. The second profile was characterized by adolescent and young adult women, victims of aggression using physical force, resulting in soft tissue traumas, mainly affecting the lower third of the face or more than one region at the same time. MCA has been demonstrated to be a powerful tool for exploring complex data related to oral–maxillofacial trauma, showing whether there is a relationship and how variables are related. This multivariate method can also be very valuable in the study of several outcomes in oral and maxillofacial surgery and supporting specialties.