Добірка наукової літератури з теми "Bridges (Dentistry)"

There has been limited use of ceramic materials for all-ceramic posterior bridges. Major reasons are the low strength, the strength scatter, and the time-dependent strength decrease of ceramics due to slow crack growth. The objective of this study was to predict the long-term failure probability and loading capability of all-ceramic bridges (Empress 1, Empress 2, In-Ceram Alumina, and ZrO2) by computational techniques. The lifetimes of different bridge model designs were predicted by means of the NASA post-processor CARES. Bridges made of zirconia showed a very high mechanical long-term reliability. Empress I and InCeram Alumina seem to be insufficient as posterior bridge materials based on this prediction. The lifetime of the all-ceramic bridges can be significantly increased by improving the design in the connector area. We conclude that computational techniques can help to judge a ceramic material and a specific ceramic bridge design with respect to mechanical reliability before clinical use.

Replacement of missing mandibular central incisor is difficult challenge in esthetic dentistry. Resin bonded bridges or maryland bridges can be considered as a treatment of choice in such conditions, which restore the oral function and esthetic of the patient. Maryland bridge preparation requires minimal preparation of the tooth and the bridge can be attached to the periodontally sound adjacent teeth.The combined use of polyethylene fibre and resin composite help achieve durable and functional result.This case report describes the case of esthetic restoration of a young women with midline spacing of mandibular anterior teeth.

Ceramic systems have limited long-term fracture resistance, especially when they are used in posterior areas or for fixed partial dentures. The objective of this study was to determine the site of crack initiation and the causes of fracture of clinically failed ceramic fixed partial dentures. Six Empress 2® lithia-disilicate (Li2O·2SiO2)-based veneered bridges and 7 experimental lithia-disilicate-based non-veneered ceramic bridges were retrieved and analyzed. Fractography and fracture mechanics methods were used to estimate the stresses at failure in 6 bridges (50%) whose fracture initiated from the occlusal surface of the connectors. Fracture of 1 non-veneered bridge (8%) initiated within the gingival surface of the connector. Three veneered bridges fractured within the veneer layers. Failure stresses of the all-core fixed partial dentures ranged from 107 to 161 MPa. Failure stresses of the veneered fixed partial dentures ranged from 19 to 68 MPa. We conclude that fracture initiation sites are controlled primarily by contact damage.

There have been significant changes in restorative dentistry since the first publication of Dental Update 50 years ago. The changes in prosthodontics are described in this article, as are the interactions with the sister disciplines of endodontics and periodontology. Conventional crowns, bridges and dentures were the main ‘tools of the trade’ in the 1970s. Adhesive materials, dental implants and bleaching have allowed a less destructive way of repairing and replacing teeth. Dentists and patients have different attitudes to dentistry today. Technology continues to improve, and how we practice continues to evolve. CPD/Clinical Relevance: Looking back over 50 years of clinical dentistry is useful to see the changes in our day-to-day practice and see the techniques which have passed the test of time.

Objective: The object of this survey study was to assess the knowledge, attitude and practice of dentists towards resin bonded bridges across Pakistan. Methodology: A cross-sectional survey study was conducted. A self-administered questionnaire was distributed among 500 dentists across Pakistan as a google form through electronic media. The questionnaire had three sections. First two sections had details about purpose of study and demographic details respectively. In the third section knowledge, attitude and practice of the participants were assessed. Knowledge and attitude were scored. Level of knowledge and attitude towards use of RBBs was correlated with other variables. Significance of factors related to RBB success was evaluated as percentages. Results: A total of 162 males (78%) and 128 females (63.1%) had adequate knowledge. Overall, 303 (75.2%) participants were inclined to use the RBB while only 100 (24.8%) were not in the favor of using this treatment. 286 participants (71%) were confident to offer this treatment to their patients however, 85% of them actually employed RBBs for ≤ 20% of their tooth replacements. Lack of skills was considered as a major hindrance to employ RBB treatment followed by the lack of technical support. Conclusion: The results of the study showed that participants are poised in knowledge regarding RBBs but they are reluctant to use this confidently because of lack of practical skills. Modest use of RBB in clinical practice is a question mark and a food for thought. Keywords: Resin Bonded Bridges, Conservative Dentistry, Minimally Invasive Dentistry.

Porcelain fused to metal (PFM) bridge is the most of treatment that commonly used as a fixed partial dentures. One of the indication for PFM bridge is to replacing the loss of posterior teeth. This case report discussed about the treatment of posterior missing teeth with PFM bridge. Objective: to explain the clinical procedures of PFM bridges to treat the patient with posterior missing teeth. Case report: A 29-years old woman came to prosthodontic clinic in Faculty of Dentistry University of Padjadjaran with chief complaint of right maxillary posterior missing teeth. The treatment planning that have been choosen for this case was the porcelain fused to metal bridge due this excellent characteristic of resistence to mastication force compared with other types of bridge such as all ceramic or all acrylic bridge. Beside that, the aesthetic achievement of this kind of bridges is more excellent than all metal bridges. Disscussion: A spatial analysis, calculation the number of abutment against which used, and selected design bridge very determine the success of this treatment. In addition to that, the clinical procedures consisting of abutment teeth preparation, an accurate impression, and appropriate cementation were needed to get the satisfactory result. Conclusions: The porcelain fused to metal bridge is a appropriate option for posterior missing teeth treatment that fullfil satisfactorical biomechanical and esthetic factors.

Thesis (MTech (Dental Technology Discipline))--Cape Peninsula University of Technology, 2007
Practitioners often modify the powder:liquid ratio of polymethyl methacrylate resins (PMMA) to improve the handling properties of the material for certain procedures or because of personal preferences. While it is known that this influences the mechanical properties of unreinforced resin materials, little is known about its effect on glass fibre reinforced PMMA resin.

Due to the increasing demand from patients and dentists for highly aesthetic and strong, metal-free restorations there has been a rapid increase in research into dental CAD CAM technique and zirconia based restorations over the last decade. Such new technology has the potential to take the place of conventional techniques and materials for fabricating indirect dental restorations in the future. In this PhD thesis, five laboratory studies were designed to investigate zirconia bridges constructed using dental CAD CAM. The studies concentrated on: 1. Ideal force applied by dentists for cementing zirconia bridges and the impact on seating. 2. The effect of firing cycles and zirconia thickness on the fit of zirconia bridges. 3. The effect of span length on the fit of three and four unit all zirconia bridges. 4. The effect of veneering on the strength of three unit zirconia bridges. 5. The fit of three unit all zirconia bridges produced by digital and conventional techniques. For these laboratory studies an ideal three unit (and four unit for study 3) fixed-fixed all ceramic bridge preparation was carried out on two plastic teeth and all SLA models and zirconia based bridges were made using the Lava COS and Lava™ CAD CAM system (3M, ESPE). In addition to the laboratory studies, a clinical audit was carried out to assess satisfaction (dentist, dental technician and patient) with zirconia based restorations (through a xvi series of questionnaires) made and fitted at Dundee Dental Hospital and School. In addition, as part of this audit a simple cost analysis was carried out to explore the differences in cost between zirconia based restorations and high fusing gold alloy based metal ceramic restorations. Four of the studies (studies 1, 2, 3 and 5) investigated the internal and marginal fit of the zirconia based restorations under differing laboratory and clinical procedures and conditions. It was found that the seating force used to cement a zirconia based bridge had no impact upon fit (Study 1). Whilst the thickness of zirconia (all-zirconia bridge and un-veneered zirconia framework) did not affect the fit of the restoration, veneering the framework did lead to a statistically significant deterioration in fit (Study 2). Although leading to a poorer fit veneering did have a positive effect in strengthening the zirconia framework, but neither un-veneered nor veneered frameworks were as strong as monolithic/all zirconia bridges (Study 4). Despite the high shrinkage during post milling sintering and the potential for greater distortion on longer span bridges, the longer span bridges investigated in Study 3 did not impact upon fit. In study 1, 2, 3 and 4 the Lava COS intra-oral scanner was used to create a digital impression of the tooth preparations and study 5 confirmed that the fit of bridges made from these impressions were better than those made using conventional addition cured silicone putty and wash impressions (Study 5). The results of the questionnaires used in the audit revealed high satisfaction rates with all stake holders and the cost analysis showed that producing zirconia based restorations can be five to six times cheaper than conventional gold based restorations. Despite the variations in fit which were found in Studies 2 and 5, all bridges produced were within what would be regarded as clinically acceptable and comparable to those produced with more traditional techniques.

The objective of this work is to study some various aspects of the modern digital workflow to produce Fixed Dental Prostheses (FDP): from the optical impression, directly in the mouth, to the finalization of the prosthetic device specific for the patient. The motivation of this study is related to the growing need around the dental world to optimize and modernize the workflows that are still essentially artisanal. Taking advantage of modern digital technologies, that are rapidly spreading in the dental field, it is possible to obtain products with the highest quality standards, with lower production costs. Moreover it is important to spread the knowledge and skills to the dentists and to the dental technicians for an optimal use of these knowledges. In particular, we have have taken into consideration the following issues of distinct particular clinical importance: - optical intraoral scanning technology: specific operative and technical performance of these digital devices were investigated with particular reference to edentulous patients who need a full-arch implants rehabilitation, - innovative ceramic materials, used to produce metalfree multilayer bridges on natural teeth using Cad-Cam technology. It was also investigated an innovative resin composite material, which is also workable with Cad-Cam technology and used for the production of single crowns on implants. The revision of the scientific literature, suggested goals and metrological aspects of the experimental program of this research. The investigations, have evaluated precision and accuracy aspects of the optical impression of implants position, the geometric coupling precision of the multilayer metal free bridge components, mechanical resistance of different types of materials, and adhesion between a recent Cad-Cam resin composite referred as, Resin Nano-Ceramic (RNC) and zirconia. Moreover the introduction of instruments and methods established in the technical-scientific field, has been provided suitable to characterize the manufacturing processes used, the materials used and the devices manufactured. More in detail, the activities involved: 1. the study, in terms of metrological performance, of the acquisition process performed by the True Definition Scanner using a clinical sample reproducing a fully edentulous arch rehabilitated with 6 implants, 2. the verification of the geometric precision of the coupling component, sub and superstructure, of multilayer metalfree bridges made with different ceramic materials (zirconia-lithium disilicate), produced by Cad-Cam technology, and assembled by two different operators; the assembly / union of the bridge components, is instead carried out manually by the dental technicians totally handmade; 3. the analysis of the mechanical behavior, static, of the multilayer metalfree bridges, cited in paragraph 2, compared with another type of multilayer prosthesis (from the same Cad projects) but made with zirconia and glass ceramic (RLT), 4. the analysis by mechanical test, both static and under fatigue, of an innovative composite material resin supplied in blocks for Cad-Cam processing: Lava Ultimate. This new composite material presents, mechanical properties (Young's modulus), more similar to the natural tooth, compared to other aesthetic materials. For this reason, it was used to produce single crowns on implants comparing two different modes of use: cementing a composite crown produced with Cad-Cam technology directly on a titanium standard abutment supplied by industry, or producing a Cad-Cam zirconia customized abutment and cementing the composite crown to this; 5.verification of bonding capacity between zirconia and Lava Ultimate, using two different resin cements by means of shear bond test. Based on the results of the test campaigns conducted in this study it can be stated that: 1 technologies of digital intraoral optical impression are able to fulfill the clinical requirements of precision even in the case of full arch implants rehabilitations, 2. multilayer metalfree bridges, made with Cad-Cam technology according to the precision requirements of digital workflow, are affected by the intervention of the dental technician during the final assembly of the bridge components, resulting in reduced quality of precision established in the Cad phase, 3 multilayer metalfreee bridges show fracture toughness values greater than or equal to the minimum values reported in the scientific literature, 4. the implants crowns made with the innovative composite material subjected to strength tests and fatigue resistance, when cemented on an customized zirconia abutment, have superior mechanical characteristics than the cheapest solution, which provides the composite crown cementation directly to a standardized titanium abutment, 5. the use of adhesive cements for luting Lava Ultimate on zirconia, allowed to highlight the opposite results regards the strenght of adhesion, measured by means of the shear bond test.
L’obiettivo di questo lavoro è studiare alcuni aspetti della moderna filiera produttiva digitale di manufatti protesici in campo dentale: dalla realizzazione dell’impronta ottica, direttamente nel cavo orale, alla finalizzazione del dispositivo protesico individualizzato per il paziente. La motivazione di questo studio risiede nell’esigenza sempre più sentita da parte di tutto il mondo dentale di ottimizzare e modernizzare i flussi di lavoro che sono ancora essenzialmente artigianali. Sfruttando le moderne tecnologie digitali, che si stanno rapidamente diffondendo in campo dentale, è possibile ottenere prodotti finiti di più alto standard qualitativo a fronte di costi di realizzazione più contenuti a condizione di diffondere ai clinici ed agli odontotecnici le conoscenze e le competenze necessarie all’utilizzo ottimale. In particolare sono stati presi in considerazione i seguenti temi di particolare rilevanza clinica: - la tecnologia di scansione ottica intraorale: sono state indagate le specificità operative e le prestazioni tecniche in particolare riferimento all’impiego per edentulie totali riabilitate mediante impianti, - i materiali ceramici innovativi, lavorabili mediante tecnologia Cad-Cam ed impiegati per realizzare protesi a ponte su denti naturali di tipo multilayer metalfree. E’ stato inoltre indagato un innovativo materiale in resina composita, anch’esso utilizzabile con tecnologia Cad-Cam ed impiegato per la realizzazione di corone singole su impianti. La revisione della letteratura tecnico scientifica, ha suggerito gli obbiettivi e gli aspetti metrologici del programma di ricerca sperimentale da condurre. Le indagini hanno riguardato aspetti di precisione ed accuratezza della lettura ottica della posizione degli impianti, di precisione geometrica di accoppiamento di protesi multilayer metal free, di resistenza meccanica di diversi tipologie di materiali e di adesione tra un recente composito a matrice resinosa, denominato Resin Nano-Ceramic (RNC) e zirconia; hanno previsto l’introduzione di strumenti e metodi consolidati in campo tecnico-scientifico, adatti a caratterizzare i processi di fabbricazione utilizzati, i materiali impiegati e i dispositivi realizzati. Più in dettaglio, l’attività ha riguardato: 1. lo studio, in termini di prestazioni metrologiche, del processo di acquisizione effettuato mediante il sistema di scansione True Definition Scanner su un campione clinico riproducente un'arcata completamente edentula riabilitata con 6 impianti; 2. la verifica della precisione geometrica di accoppiamento delle componenti, sotto e sovrastruttura, di protesi metalfree multilayer realizzate con materiali ceramici diversi (zirconia-disilicato di litio) prodotte mediante tecnologia Cad-Cam, e assemblate da due operatori diversi; l’assemblaggio/unione delle componenti, dei singoli ponti, viene invece realizzato manualmente dall’odontotecnico con tecnica totalmente artigianale; 3. l’analisi del comportamento meccanico, statico, delle protesi metalfree multilayer, citate al punto 2, confrontate con un altro tipo di protesi multilayer (provenienti dagli stessi progetti Cad) ma costituite da zirconia e ceramica feldspatica (RLT), 4. l’analisi mediante prova meccanica, statica e a fatica, della resistenza di un innovativo materiale in resina composita fornito in blocchetti per lavorazione Cad-Cam: Lava Ultimate. Questo nuovo materiale composito presenta, rispetto ad altri materiali estetici quanto a proprietà meccaniche dichiarate, (modulo di Young), un comportamento più simili al dente naturale. In quest’ottica, è stato utilizzato per realizzare corone singole su impianti, confrontando due modalità diverse di impiego: cementando una corona realizzata con questo composito e prodotta con tecnologia Cad-Cam direttamente su un pilastro standard in titanio fornito dall’industria, o realizzando con lavorazione Cad-Cam una sottostruttura in zirconia individualizzata e cementando su quest’ultima la corona in composito; 5. la verifica delle capacità adesive tra zirconia e Lava Ultimate, utilizzando due diversi cementi resinosi mediante test di taglio. Sulla base dei risultati delle campagne sperimentali condotte in questo studio è possibile affermare che: 1 le tecnologie di impronta ottica digitale intraorale sono in grado di rispondere ai requisiti clinici di precisione anche nel caso di arcate complete riabilitate su impianti, 2. le protesi multilayer metalfree, realizzate con tecnologia Cad-Cam secondo i requisiti di precisione propri dal workflow digitale, risentono dell’intervento di assemblaggio finale che esegue l’odontotecnico, con conseguente riduzione delle qualità di precisione stabilite in fase progettuale, 3. i ponti multilayer metalfreee presentano valori di resistenza alla frattura superiori o uguali ai valori minimi riportatati dalla letteratura scientifica 4. le corone su impianti realizzate con l’innovativo materiale composito, sottoposto a prove di resistenza statica e a fatica, quando cementate su un moncone individualizzato in zirconia, hanno caratteristiche meccaniche superiori alla soluzione più economica, che prevede la cementazione della corona direttamente ad un pilastro standardizzato in titanio. 5. l’utilizzo di cementi adesivi per cementare Lava Ultimate su zirconia, ha permesso di evidenziare comportamenti opposti per quanto riguarda le forze di adesione misurate con il test di taglio.

PURPOSE: To determine the potential discoloration of provisional materials by exposure to beverages and evaluate the efficacy of simulated tooth-brushing on stain removal and the effect on surface roughness. METHODS: Materials included: Jet Set-4 (Lang), Protemp Plus (3M ESPE), Luxatemp (DMG), Artbloc (Merz), Telio-CAD (Ivoclar), and Vita-CAD (Vita). Specimens (n=10/group) were immersed in: distilled water, coffee, red wine, tea, coke and cranberry juice. Color measurements were taken (Xritei5 spectrophotometer) at: baseline, 24 hours, 4 and 8 weeks. Specimens in coffee and red wine for 8 weeks were exposed to tooth-brushing for three minutes and color measurements were taken subsequently. Color differences (ΔE) after treatments were calculated using one-way ANOVA, MANOVA and post hoc Tukey test. Another group of specimens (n=10/group) were exposed to tooth-brushing under a 1.91N load using toothpaste slurry (Crest® Cavity Protection) for 20,000 cycles in two modes: soft and medium bristles (both Oral B Indicator®). Surface roughness was measured using a Mitutoyo SJ201 profilometer before and after brushing. Surface roughness Ra values were compared using one-way ANOVA and post hoc Tukey test. RESULTS: Coke and water had no significant discoloration effect (p>0.05). Red wine and coffee exhibited the highest discoloration effect. CAD-CAM blocks showed significantly lower color change, at all durations, and after brushing (p<0.001). Tooth-brushing had a significant effect (Ra) on Telio-CAD, Artbloc, Jet Set-4 and Vita-CAD. Protemp-Plus and Luxatemp groups showed no significant difference. CONCLUSIONS: Traditional materials showed less color stability when compared to CAD/CAM blocks. Tooth-brushing effect varies depending on bristle and material type.

AbstractOral and maxillofacial surgery is a bridge between medicine and dentistry and the debate of pursuing a dual degree is a hot to trot topic worldwide, new residents should always weigh their abilities and focus on additional training in respective fields to improve their expertise. The experience of starting a practice in the scenario where more than 100-150 amateur oral surgeons are competing seems to be scary. The chapter deals with the problems faced by new surgeons in establishing their practice along with the solution to thrive in this competitive world. The chapter also emphasizes on the process of planning and setting up of a maxillofacial hospital along with the art of management of finances to guide the new surgeons.

Contents. Treatment planning for patients with missing teeth. Bridges. Bridges—design. Bridges—practical stages. Bridge failures. Resin-bonded bridges. Removable partial dentures—principles. Removable partial dentures—components. Removable partial dentures—design. Removable partial dentures—clinical stages. Immediate complete dentures. Complete dentures—principles. Complete dentures—impressions. Complete dentures—recording the occlusion. Complete dentures—trial insertion. Complete dentures—fitting. Denture maintenance. Cleaning dentures. Denture problems and complaints. Candida and dentures. Denture copying. Overdentures. Implantology. Dentistry and the older patient. Age changes. Dental care for the elderly.

Abstract Additive manufacturing (AM), also referred to as three-dimensional printing or rapid prototyping, is a set of technologies that has rapidly evolved and has drawn much research attention in the manufacturing of high value-added products. This article focuses on dentistry, one of the fields in which AM has gained much traction. It discusses the AM processes used to produce dentures, crowns, and bridges. Digitization techniques, which are the first step and provide the CAD model for AM processes, are presented. Scanning technologies that are widely used in dental manufacturing are presented in detail, and the strengths and weaknesses of each process within their applications are discussed. AM processes are discussed in detail, and the materials that are widely used in AM-embedded dental manufacturing are briefly surveyed. The final section concludes with remarks and a preview of future research and practice directions.

A pain-free, functioning, and good-looking dentition for a lifetime seems a reasonable goal! Is this what dentists do? An advertisement for a North American dental practice recently suggested that dentists practising general dentistry provide amalgam and composite fillings, sealants, cosmetic dentistry, pulp and root canal treatment, crown and bridges, dentures, and dental implants. Moreover, they do minor oral surgery, gum disease treatment, and occasionally temporomandibular joint (TMJ) therapy, tobacco cessation, and nutrition counselling. The topics listed in the first sentence comprise the daily work in general dentistry, but do you realize that 85% of these are a direct consequence of dental caries? Yet dental caries is not mentioned as the main reason for most dental treatments. Restorative treatment is the focus of dentistry. The disease dental caries is the only disease which has been combatted with metals and composites for more than a century. Some 50 years ago the concept of prevention became fashionable. Now restorative treatment was described as ‘secondary prophylaxis’ because it was considered that once the inevitable dental caries had occurred, it had to be treated (i.e. restored) to prevent further break down of the teeth and the dentition. Therefore, it is not surprising that the most time in the dental curriculum is devoted to the many skilled restorative procedures. These have to be conducted in a moist, slippery, small, and moving oral cavity attached to a person who may find the procedure unpleasant! No wonder it is difficult to perform intra-oral restorative work of high quality as part of oral rehabilitation, and no wonder so much time in the curriculum is devoted to these aspects. However, supposing it was possible to prevent or control the disease so that restorations are reduced to a minimum? This control of caries is what this book is about! Seven chapters present the essentials of what is known about dental caries. The observations will be based on current scientific evidence. This is a hands-on book, which means that what is suggested and observed should have immediate implications for how patients may be treated.

This chapter introduces the scope of the book—bioMIMETICS can be described as an innovative form of technology that imitates (or mimics) nature in order to improve human lives via creating desirable solutions. It is the study of nature and natural phenomena, principles, and underlying mechanisms, to obtain bio-inspired that may benefit various applied scientific and technological disciplines. Smart/Intelligent nano-bioMaterials for Tissue Engineering and Regenerative Medicine are a fine example. Yet, biomimicry can go above and beyond the simplistic inspiration and use of natural properties as the basis for innovation of new products. It bridges the gap between the lab and the industry, via the intra-disciplinary design and formulation of functional solutions combining knowledge, methods, techniques, and advances in the fields of chemistry, biology, architecture, engineering, medicine, pharmaceutics, dentistry, and biomedical engineering. Three-Dimensional Printing, Hybrid nanoCoatings, and Stimuli-sensitive and -responsive Cell/Drug Delivery Systems, and Robotics are some of the topics covered in this new book. In this first chapter, a general overview of bio-inspired materials, technologies, and strategies, collectively known as “bioMiMETICS,” is presented to bridge the gap between the laboratory “bench-top” and translational application, particularly, the clinic or “bed-/chair-side,” with a focus on “REGENERATIVE DENTISTRY” and the “CRANIO-MAXILLO-FACIAL bio-COMPLEX.”