Análise extensométrica de cargas estáticas axiais e não axiais em próteses implantossuportadas de três elementos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo de preparos e da forma da infraestrutura na distribuição de tensões em prótese parcial fixa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação fotoelástica de overdentures mandibulares sobre implantes com três diferentes sistemas de retenção e prótese protocolo de Branemark

Pós-graduação em Odontologia - FOA

Considerações gerais sobre prótese fixa adesiva

The success rate of resin-bonded fixed partial dentures is directly related to the adhesive system and the tooth preparation design for good retention. These resin-bonded bridges represent a prosthodontic alternative, based on their costeffectiveness, conservative techniques, and ease of laboratory manufacturing. Through a thorough review of the literature, this study aimed to report on cavity designs, types of materials used, and the advantages and disadvantages of the resin-bonded fixed partial denture. One of significant advantages of the resin-bonded fixed partial dentures is the conservation of the tooth structure, whereas its main disadvantage includes aesthetic limitations, given that the alloy may in fact be visible. Preparation design, cement type, and casting alloy type, as well as surface treatment, are among the factors that influence the longevity of resin-bonded fixed partial dentures. Treatments with resin-bonded fixed partial dentures present a bright outlook regarding the conservation of tooth structures, as well as a high level of success.

Recuperação da dimensão vertical em pacientes com parafunção severa

The association between emotional stress and intense bruxism has as consequence the Temporomandibular Disorder (TMD), which is an increasingly apparent problem at the dental clinic, requiring judicious means of diagnosis and especially treatment.. Several factors, of equivalent importance, may be related to the DTM, one of them is the loss of vertical dimension of occlusion (VDO), and parafunctional habits and also the loss of stable contacts between the posterior teeth or lack thereof, which generates an increase functional anterior teeth for excessive wear or buccal and consequent.. This paper proposes using a clinical case, to present and discuss the steps for clinical diagnosis, planning and execution of oral rehabilitation with Fixed Partial Denture for restoring vertical dimension of occlusion in a patient with severe parafunction.. Oral rehabilitation of these patients should be carefully planned, respecting the functional and aesthetic aspects.. The parafunction control by monitoring the Temporomandibular Disorder is essential to the longitudinal prediction of rehabilitation performed in these types of rehabilitative treatment.

Reabilitação de maxila atrófica com tecido ósseo homógeno e prótese fixa implantossuportada

The techniques of bone reconstruction for atrophic maxillae have been improved in order to promote bone tissue growth in both height and thickness. The grafts performed with use of autogenous bone is considered the gold standard by most researchers, for demonstrating osteogenic capacity and not to promote antigenic response. However, this type of grafting is not possible to get bone tissue in large quantity for extensive renovations. In recent years, alternatives have been researched to overcome the limitations of autogenous bone. Several alternatives have been investigated to supply the disadvantages of autogenous bone grafts. In such studies, allogeneic bone grafts which are obtained from individuals with different genetic load, but from the same species have been extensively used. They can be indicated in cases of arthrosplasty, surgical knee reconstruction, and large bone defects as well as in oral and maxillofacial reconstruction. Besides showing great applicability and biocompatibility, this type of bone is available in unlimited quantities. To rehabilitate atrophic maxillae an option that has been performed with high success rate is the reconstruction with bone graft followed by osseointegrated dental implants to rehabilitate the patient aesthetics and functionally. This paper aims to show the feasibility of allogenic bone as material for reconstruction of atrophic maxilla, and subsequent rehabilitation with metal ceramic fixed prosthesis implant and dental restoration with accompanying three years through literature review and clinical case report.

Estudo retrospectivo de implantes osseointegrados instalados imediatamente após exodontias

Objectives: to evaluate implant survival immediately placed after tooth extraction considering different sites, prosthodontic modalities, and the need for biomaterials. Material and methods: dental records of 500 patients treated with dental implants between 2004 and 2011 were screened. Results: only 200 records (20%) corresponded to immediate implants. Reasons for tooth extraction included extensive caries, bone loss, and root fractures. From the 197 immediate dental implants, 86 were placed in the maxilla with a survival rate of 93.9% and 111 in the mandible (survival rate of 99.1%). The overall survival rate was 97.46%. Prosthodontic modalities identified were: Brånemark classic complete denture screwed prostheses (36%), overdentures (5.6%), fixed partial denture (31%), and single-tooth prostheses (27.4%). Also, it was observed that in 33% of cases there was a need for the use of grafts and/or biomaterials. Conclusion: it can be concluded that, when correctly indicated, immediate implants are an excellent choice. The anterior mandibular region, screwed and overdenture-type prostheses presented higher success rates when associated to immediate implant placement. The need for bone graft/biomaterial does not affect the clinical results.

Evaluation of the flexural strength and elastic modulus of resins used for temporary restorations reinforced with particulate glass fibre

Objective: The flexural strength and the elastic modulus of acrylic resins, Dencor, Duralay and Trim Plus II, were evaluated with and without the addition of silanised glass fibre. Materials and methods: To evaluate the flexural strength and elastic modulus, 60 test specimens were fabricated with the addition of 10% ground silanised glass fibres for the experimental group, and 60 without the incorporation of fibres, for the control group, with 20 test specimens being made of each commercial brand of resin (Dencor, Duralay and Trim Plus II) for the control group and experimental group. After the test specimens had been completed, the flexural strength and elastic modulus tests were performed in a universal testing device, using the three-point bending test. For the specimens without fibres the One-Way Analysis of Variance and the complementary Tukey test were used, and for those with fibres it was not normal, so that the non-parametric Mann-Whitney test was applied. Results: For the flexural strength test, there was no statistical difference (p > 0.05) between each commercial brand of resin without fibres [Duralay 84.32(+/- 8.54), Trim plus 85.39(+/- 6.74), Dencor 96.70(+/- 6.52)] and with fibres (Duralay 87.18, Trim plus 88.33, Dencor 98.10). However, for the elastic modulus, there was statistical difference (p > 0.01) between each commercial brand of resin without fibres [Duralay 2380.64 (+/- 168.60), Trim plus 2740.37(+/- 311.74), Dencor 2595.42(+/- 261.22)] and with fibres (Duralay 3750.42, Trim plus 3188.80, Dencor 3400.75). Conclusion: The result showed that the incorporation of fibre did not interfere in the flexural strength values, but it increased the values for the elastic modulus.

Prosthetic misfit of implant-supported prosthesis obtained by an alternative section method

PURPOSE. Adequate passive-fitting of one-piece cast 3-element implant-supported frameworks is hard to achieve. This short communication aims to present an alternative method for section of one-piece cast frameworks and for casting implant-supported frameworks. MATERIALS AND METHODS. Three-unit implant-supported nickel-chromium (Ni-Cr) frameworks were tested for vertical misfit (n = 6). The frameworks were cast as one-piece (Group A) and later transversally sectioned through a diagonal axis (Group B) and compared to frameworks that were cast diagonally separated (Group C). All separated frameworks were laser welded. Only one side of the frameworks was screwed. RESULTS. The results on the tightened side were significantly lower in Group C (6.43 +/- 3.24 mu m) when compared to Groups A (16.50 +/- 7.55 mu m) and B (16.27 +/- 1.71 mu m) (P<.05). On the opposite side, the diagonal section of the one-piece castings for laser welding showed significant improvement in the levels of misfit of the frameworks (Group A, 58.66 +/- 14.30 mu m; Group B, 39.4.8 +/- 12.03 mu m; Group C, 23.13 +/- 8.24 mu m) (P<.05). CONCLUSION. Casting diagonally sectioned frameworks lowers the misfit levels. Lower misfit levels for the frameworks can be achieved by diagonally sectioning one-piece frameworks. [J Adv Prosthodont 2012;4:89-92]

[Anterior teeth esthetics with the SPI implant system]

Replacement of maxillary front teeth with a fixed, implant supported partial denture with a high laugh line is a demanding procedure. For an optimal esthetic result, no deficiency of bone or soft tissue is acceptable. Submerged implant healing has often been recommended for better predictability in esthetically demanding situations. This case report shows the rehabilitation with a fixed implant supported reconstruction in the upper front and a single implant supported crown in the premolar region. Teeth had to be extracted because of apical lesions, periodontal the gingiva. The technique of delayed, submerged implant placement in the region of 11, 21 and 22 was applied and in the region of 15 a transmucosal implant healing. With a fixed, implant supported partial denture the mucosa in the upper front was conditioned. Ten months after implantation the definitive screwed, fixed partial denture on SPI ELEMENT implants was successfully integrated. In the region 15 a single crown transversally screwed was fixed on a SPI ONE TIME implant. Radiographic data two years after implantation showed a well established periimplant crestal bone level. No prosthetic complications had occurred since the insertion of the reconstruction twelve months ago.

[The stamp technique for direct composite restoration]

The indications for direct resin composite restorations are nowadays extended due to the development of modern resin materials with improved material properties. However, there are still some difficulties regarding handling of resin composite material, especially in large restorations. The reconstruction of a functional and individual occlusion is difficult to achieve with direct application techniques. The aim of the present publication was to introduce a new "stamp"-technique for placing large composite restorations. The procedure of this "stamp"-technique is presented by three typical indications: large single-tooth restoration, occlusal rehabilitation of a compromised occlusal surface due to erosions and direct fibre-reinforced fixed partial denture. A step-by-step description of the technique and clinical figures illustrates the method. Large single-tooth restorations can be built-up with individual, two- piece silicone stamps. Large occlusal abrasive and/or erosive defects can be restored by copying the wax-up from the dental technician using the "stamp"-technique. Even fiber-reinforced resin-bonded fixed partial dentures can be formed with this intraoral technique with more precision and within a shorter treatment time. The presented "stamp"-technique facilitates the placement of large restoration with composite and can be recommended for the clinical use.

A systematic review of the performance of ceramic and metal implant abutments supporting fixed implant reconstructions

OBJECTIVES: The objective of this systematic review was to assess the 5-year survival rates and incidences of complications associated with ceramic abutments and to compare them with those of metal abutments. METHODS: An electronic Medline search complemented by manual searching was conducted to identify randomized-controlled clinical trials, and prospective and retrospective studies providing information on ceramic and metal abutments with a mean follow-up time of at least 3 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data abstraction was performed independently by three reviewers. Failure rates were analyzed using standard and random-effects Poisson regression models to obtain summary estimates of 5-year survival proportions. RESULTS: Twenty-nine clinical and 22 laboratory studies were selected from an initial yield of 7136 titles and data were extracted. The estimated 5-year survival rate of ceramic abutments was 99.1% [95% confidence interval (CI): 93.8-99.9%] and 97.4% (95% CI: 96-98.3%) for metal abutments. The estimated cumulative incidence of technical complications after 5 years was 6.9% (95% CI: 3.5-13.4%) for ceramic abutments and 15.9% (95% CI: 11.6-21.5%) for metal abutments. Abutment screw loosening was the most frequent technical problem, occurring at an estimated cumulative incidence after 5 years of 5.1% (95% CI: 3.3-7.7%). All-ceramic crowns supported by ceramic abutments exhibited similar annual fracture rates as metal-ceramic crowns supported by metal abutments. The cumulative incidence of biological complications after 5 years was estimated at 5.2% (95% CI: 0.4-52%) for ceramic and 7.7% (95% CI: 4.7-12.5%) for metal abutments. Esthetic complications tended to be more frequent at metal abutments. A meta-analysis of the laboratory data was impossible due to the non-standardized test methods of the studies included. CONCLUSION: The 5-year survival rates estimated from annual failure rates appeared to be similar for ceramic and metal abutments. The information included in this review did not provide evidence for differences of the technical and biological outcomes of ceramic and metal abutments. However, the information for ceramic abutments was limited in the number of studies and abutments analyzed as well as the accrued follow-up time. Standardized methods for the analysis of abutment strength are needed.

Influence of thermal and mechanical cycling on the flexural strength of ceramics with titanium or gold alloy frameworks

Objectives: The aim of this study was to evaluate the effect of thermal and mechanical cycling alone or in combination, on the flexural strength of ceramic and metallic frameworks cast in gold alloy or titanium. Methods: Metallic frameworks (25 mm × 3 mm × 0.5 mm) (N = 96) cast in gold alloy or commercial pure titanium (Ti cp) were obtained using acrylic templates. They were airborne particle-abraded with 150 μm aluminum oxide at the central area of the frameworks (8 mm × 3 mm). Bonding agent and opaque were applied on the particle-abraded surfaces and the corresponding ceramic for each metal was fired onto them. The thickness of the ceramic layer was standardized by positioning the frameworks in a metallic template (height: 1 mm). The specimens from each ceramic-metal combination (N = 96, n = 12 per group) were randomly assigned into four experimental fatigue conditions, namely water storage at 37 °C for 24 h (control group), thermal cycling (3000 cycles, between 4 and 55 °C, dwell time: 10 s), mechanical cycling (20,000 cycles under 10 N load, immersion in distilled water at 37 °C) and, thermal and mechanical cycling. A flexural strength test was performed in a universal testing machine (crosshead speed: 1.5 mm/min). Data were statistically analyzed using two-way ANOVA and Tukey's test (α = 0.05). Results: The mean flexural strength values for the ceramic-gold alloy combination (55 ± 7.2 MPa) were significantly higher than those of the ceramic-Ti cp combination (32 ± 6.7 MPa) regardless of the fatigue conditions performed (p < 0.05). Mechanical and thermo-mechanical fatigue decreased the flexural strength results significantly for both ceramic-gold alloy (52 ± 6.6 and 53 ± 5.6 MPa, respectively) and ceramic-Ti cp combinations (29 ± 6.8 and 29 ± 6.8 MPa, respectively) compared to the control group (58 ± 7.8 and 39 ± 5.1 MPa, for gold and Ti cp, respectively) (p < 0.05) (Tukey's test). While ceramic-Ti cp combinations failed adhesively at the metal-opaque interface, gold alloy frameworks exhibited a residue of ceramic material on the surface in all experimental groups. Significance: Mechanical and thermo-mechanical fatigue conditions decreased the flexural strength values for both ceramic-gold alloy and ceramic-Ti cp combinations with the results being significantly lower for the latter in all experimental conditions. © 2007 Academy of Dental Materials.

Removable Partial Dentures: Use of Rapid Prototyping

The CAD/CAM technology associated with rapid prototyping (RP) is already widely used in the fabrication of all-ceramic fixed prostheses and in the biomedical area; however, the use of this technology for the manufacture of metal frames for removable dentures is new. This work reports the results of a literature review conducted on the use of CAD/CAM and RP in the manufacture of removable partial dentures.

Clinical Performance of Screw- Versus Cement-Retained Fixed Implant-Supported Reconstructions- A Systematic Review.

PURPOSE To assess the survival outcomes and reported complications of screw- and cement-retained fixed reconstructions supported on dental implants. MATERIALS AND METHODS A Medline (PubMed), Embase, and Cochrane electronic database search from 2000 to September 2012 using MeSH and free-text terms was conducted. Selected inclusion and exclusion criteria guided the search. All studies were first reviewed by abstract and subsequently by full-text reading by two examiners independently. Data were extracted by two examiners and statistically analyzed using a random effects Poisson regression. RESULTS From 4,324 abstracts, 321 full-text articles were reviewed. Seventy-three articles were found to qualify for inclusion. Five-year survival rates of 96.03% (95% confidence interval [CI]: 93.85% to 97.43%) and 95.55% (95% CI: 92.96% to 97.19%) were calculated for cemented and screw-retained reconstructions, respectively (P = .69). Comparison of cement and screw retention showed no difference when grouped as single crowns (I-SC) (P = .10) or fixed partial dentures (I-FDP) (P = .49). The 5-year survival rate for screw-retained full-arch reconstructions was 96.71% (95% CI: 93.66% to 98.31). All-ceramic reconstruction material exhibited a significantly higher failure rate than porcelain-fused-to-metal (PFM) in cemented reconstructions (P = .01) but not when comparing screw-retained reconstructions (P = .66). Technical and biologic complications demonstrating a statistically significant difference included loss of retention (P ≤ .01), abutment loosening (P ≤ .01), porcelain fracture and/or chipping (P = .02), presence of fistula/suppuration (P ≤ .001), total technical events (P = .03), and total biologic events (P = .02). CONCLUSIONS Although no statistical difference was found between cement- and screw-retained reconstructions for survival or failure rates, screw-retained reconstructions exhibited fewer technical and biologic complications overall. There were no statistically significant differences between the failure rates of the different reconstruction types (I-SCs, I-FDPs, full-arch I-FDPs) or abutment materials (titanium, gold, ceramic). The failure rate of cemented reconstructions was not influenced by the choice of a specific cement, though cement type did influence loss of retention.