Prostheses and implants

Top PDF Prostheses and implants:

Stress analysis in oral obturator prostheses over parallel and tilted implants: photoelastic imaging

Stress analysis in oral obturator prostheses over parallel and tilted implants: photoelastic imaging

Abstract. This study aimed to evaluate the stress distribution through the photoelastic method in implant-retained palatal obturators prostheses. Two photoelastic models with bucco-sinusal communication were fabricated, one model without implants and another with two parallel implants and one tilted in the molar region. A conventional obturator prosthesis and five implant-retained obturators dentures with different attachment systems were fabricated: OR, three individualized O-rings; BC, bar clip; BOC, implants splinted by bars associated with two O-rings positioned at the center of the bar; OD, implants splinted by bars associated with two O-rings positioned in distal cantilever; and BOD, implants splinted by bars with clips associated with two O-rings positioned in distal cantilever. Each assembly (model/attachment system/prosthesis) was positioned in a circular polariscope and a load of 100 N was applied on each implant. The results were obtained by observing the photographic record of the tensions in the photoelastic models resulting from the application of load. It can be observed that a larger amount of stress fringes on BC system. It was concluded that the attachment system has a direct influence on the stress distribution of implant-retained obturator prostheses, with the three individualized O-rings exhibiting the lowest stress values, and tilted implants presented a biomechanical behavior similar to parallel implants. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI. [DOI: 10.1117/1.JBO.18.10.106009]
Mostrar mais

6 Ler mais

Retrospective evaluation of the survival rate of single tooth prostheses supported in external hexagonal implants: mean follow-up of 9 years

Retrospective evaluation of the survival rate of single tooth prostheses supported in external hexagonal implants: mean follow-up of 9 years

Introduction: The use of osseointegrated dental implants for the rehabilitation of patients has revolutionized dentistry. Objective: To retrospectively evaluate the survival rate and the frequency of complications with external hexagon platform supporting single crowns. Material and method: Dental forms of 110 patients who received 143 implants at the Ilapeo College (2004-2015) were used. The variables were: age, gender, systemic involvement at the time of surgery, region, implant design, type of surface, fixation system, pillar type and prosthesis material. The outcome variables were the incidence of complications in the implant or prosthesis and time in use. The mean follow-up period was 9 years. Result: 32.8% had some systemic disease. Ninety-six implants (67.1%) were installed in the maxilla and 47 (32.9%) in the mandible, 87 (60.8%) were in the posterior region and 56 (39.2%) in the anterior region, while 40 (28%) were placed in regions that had received bone reconstruction. The majority (97.2%) of the implants presented surface treatment, 42% had a cylindrical design and 58% were tapered. The majority of the prosthetic components (89.6%) used were UCLAs and most of the prostheses were fused-to-metal (79.7%). The rate of prosthetic complications was 19.58% and three implants had been lost (97.9% survival rate). There was no statistical difference between the variables analyzed for both the occurrence of prosthetic complications and for the loss of the implant. Conclusion: Implants with external hexagon connection were an effective and predictable option to support crowns and had high survival rates.
Mostrar mais

5 Ler mais

The maxillary lateral incisor in the rehabilitation of cleft lip and palate

The maxillary lateral incisor in the rehabilitation of cleft lip and palate

Our results revealed indication of 17 prostheses and 10 implants, and the space corresponding to the maxillary lateral incisor on the cleft side was closed by orthodontic mesial movement in 53 individuals (Table 3). When necessary and possible, the mesial movement of canine is favorable to reduce the utilization of prostheses and implants. Most lateral incisors on the non-cleft side were maintained. The accomplishment of bone graft before eruption of the incisors provides bone support for the eruption of these teeth, restoring the maxillary arch shape and enhancing their retention and gingival health. The burden of care may be reduced by minimizing the treatment stages and allowing earlier treatment completion, eliminating the need for rehabilitation with prostheses in adulthood 11,17 and providing more favorable esthetic results by closing the space with a natural tooth. This aspect highlights the importance of bone graft and orthodontics in individuals with the lateral incisor.
Mostrar mais

6 Ler mais

Braz. Dent. J.  vol.26 número1

Braz. Dent. J. vol.26 número1

This treatment approach provided more comfortable rehabilitation and psychological benefits for the child, as demonstrated in a nother case report (21). However, our case presents a short-term follow-up. Further clinical evaluations must be performed each six months to observe the need of mini-implant replacements and/or substitution of prostheses due to the growth and development processes. There is not enough evidence on the ideal time for mini- implant placement and the minimum time required for monitoring (12,22,23). The monitoring of conventional dental prostheses and implants varies between 3 and 12 months (1,24,25).
Mostrar mais

4 Ler mais

Oral Implant-Prostheses: New Teeth for a Brighter Brain.

Oral Implant-Prostheses: New Teeth for a Brighter Brain.

After radiographic bone examinations, two or three one-piece implants (3P Implafavourite, Torino, Italy), were inserted to replace the first and second molar of the mandibular arch on the left (n = 4) or the right side (n = 5). The inserted implants (n = 22) were made by a single block and screwed into a hole drilled into the bone without preliminary crest incision, piercing directly the gums. Their dimensions (diameter/length) corresponded to 4.5/10 mm (n = 10), 4.5/12 mm (n = 4) or 5.2/10 mm (n = 8). Preliminary local anaesthesia was induced by infiltra- tion with articaine/epinephrine (Pierrel, Italy, 1/100000, 2cc). Soon after the implant place- ment, dental impressions were taken so to manufacture the artificial prostheses (crowns) to be mounted on the implants. The occlusal contacts of prostheses with antagonist teeth were cir- cumscribed to dental vestibular cusps. An antimicrobial prophylaxis (Amoxycillin, Pfizer, Italy, 500 mg, twice daily) was administered for 3 days, starting 1 hour before surgery. Follow- ing the surgery, analgesic (Nimesulide, SANDOZ S.P.A, Italy, 100 mg, twice daily) was deliv- ered for 2 days.
Mostrar mais

21 Ler mais

Int. braz j urol.  vol.37 número1

Int. braz j urol. vol.37 número1

As occurs in inlatable implants, when im- planting malleable prostheses through the infrapubic access care must also be taken regarding the possibil- ity of lesion to the vascular-nervous bundle. On the other hand, the approach through the dorsal surface of the corpora cavernosa has a natural capacity for anatomical protection of the urethra, not requiring transurethral catheterism. This beneit is of the utmost importance when considering possible causes of per and postoperative morbidity (18).

6 Ler mais

J. Appl. Oral Sci.  vol.15 número2

J. Appl. Oral Sci. vol.15 número2

distribution of osseointegrated implants using finite element analysis and concluded that load transmission in screwed prostheses is often concentrated at the gold screw attaching the crown to abutment, which acts as a safety device. In cemented prostheses, the cement and abutment screw receive this load, mainly shear forces. In the same study, these authors did not find significant differences between the use of resin or ceramic in the occlusal platform.

4 Ler mais

Stress analysis in oral obturator prostheses: Imaging photoelastic

Stress analysis in oral obturator prostheses: Imaging photoelastic

The photoelastic model II was confectioned by placing three implants in the second model, which was perforated in the regions of upper incisive, canine, and first molar using a paral- lelometer. After perforation, the implants analogues with 3.75 × 13 mm and 4.1 mm platforms (Neodent, Curitiba, Paraná, Brazil) were inserted and fixed with Duralay acrylic resin (Duralay Reliance Dental MFG Co Worth, IC, USA), so that the analogue platform remains at the same level of the alveolar ridge.

4 Ler mais

Singlestage  implants for nasal prosthodontic  : a clinical report

Singlestage implants for nasal prosthodontic : a clinical report

Malignant tumors in the nasal region may be treated by means of invasive surgical procedures, with large facial losses. Nasal prostheses, retained by osseointegrated facial implants, instead of plastic surgery, will, in most patients, offer good biomechanical and cosmetic results. This clinical report describes the prosthetic rehabilitation of a patient with nasal cancer who had the entire nasal vestibule removed in a single-stage surgical procedure in order to shorten the rehabilitation time. The nasal prosthesis was built on a 3-magnet bar and was made of platinum silicone with intrinsic pigmentation, thereby restoring the patient’s appearance and self-esteem. The authors concluded that single-stage implants may reduce the rehabilitation time to as little as 1 month, and the correct use of materials and techniques may significantly improve the nasal prosthesis. (J Prosthet Dent 2015;114:293-296)
Mostrar mais

4 Ler mais

Int. braz j urol.  vol.42 número6

Int. braz j urol. vol.42 número6

Skin flora are the most common source of PPIs; those organisms are introduced at the time of device implantation. Staphylococcus epidermidis is the most common organism cultured in infected prostheses, and it accounts for 35-80% of all posi- tive cultures (8, 24). Parsons et al. also showed that Staphylococcus epidermidis was the most common organism cultured from infected prostheses and uri- nary sphincters (25). Similarly, Staphylococcus epi- dermidis was the most common isolated organism from revised penile implants that were revised owing to causes other than infection (15, 21). These orga- nisms are of low virulence and are accessed during the implantation and survive in a biofilm secreted by the bacteria themselves. Our results confirmed that Staphylococcus epidermidis is the most com- mon cultured organism in uninfected, revised penile prostheses. Staphylococcus aureus and Escherichia coli have also been shown to play a role in PPI (21, 26, 27). We additionally cultured Staphylococcus hominis, beta hemolytic streptococcus and Proteus mirabilis from the non-infected devices.
Mostrar mais

7 Ler mais

Custom-made root analogue zirconia implants

Custom-made root analogue zirconia implants

Following technological developments in dentistry, patients have desired more esthetic oral rehabilitations that has led to the improvement of metal-free structures for implant-supported prostheses (Navar et al., 2015). Ceramic materials with tooth-like color (Manicone et al., 2007) and high biocompatibility (Navar et al., 2015) has had an increased demand on all-ceramic structures of more than 12% per year (Chevalier, 2006). It is noteworthy that the dental community has seen the aesthetical and mechanical benefits of zirconia-based materials, which have made it a potential to replace titanium implants (Chahine et al., 2011). Zirconia-based implants have become a solution for certain cases considering morphological aspects of peri-implant soft tissues and patient phenotype (Gungor and Yilmaz, 2016; Mobilio, 2013). The color of yttria-stabilized tetragonal zirconia polycrystalline (YTZP) can vary depending on the oxide content to mimic the color of natural teeth. That is a significant outcome to overcome aesthetic issues of implant system related to the use of titanium (Mangano, 2012). Considering mechanical properties YTZP has a Young´s modulus around 210- 240 GPa associated with a three-bending-strength ranging from 900 to 1200 MPa (Langhoff, 2008; Piconi and Maccauro, 1999). Additionally, YTZP is a biologically inert material possessing a high biocompatibility that can provide osseointegration (Pirker and Kocher, 2008; Pirker et al., 2011; Pirker and Kocher, 2009).
Mostrar mais

37 Ler mais

Biocompatibility and biodegradation studies of subconjunctival implants in rabbit eyes.

Biocompatibility and biodegradation studies of subconjunctival implants in rabbit eyes.

Samples were immersed in a closed vial containing 5 ml Phosphate Buffered Saline (PBS, pH 7.4). PBS was prepared by dissolving PBS tablets into 1 liter deionized water. All vials were incubated at 37uC throughout the study. The buffer was refreshed every week, and at every predetermined time point, samples were taken out, rinsed with deionized water and dried in 37 uC vacuum oven for 7 days, before testing. Degradation of PLGA50/50 and PLC 70/30 was monitored by film thickness (measured by Elcometer 456), water absorption, weight loss and weight average molecular mass (Mw) and poly dispersity index(PDI). Dried samples were dissolved in chloroform (1–5 mg/ml) and filtered through 0.22 m m regenerated cellulose syringe driven filters before test. Weight average molar mass and poly dispersity of the sample were determined by gel permeation chromatography (GPC, Agi- lent 1100) at 35 uC, using Agilent PLgel 5 m m mixed-C column, under a flow rate of 1 ml chloroform per minute, using a Re- fractive Index Detector (RID).
Mostrar mais

11 Ler mais

Productive performance, composition and carcass yield of lambs treated with zeranol

Productive performance, composition and carcass yield of lambs treated with zeranol

production. These substances have hormonal properties and act on the animal metabolic processes, improving nitrogen balance in the body and increasing the protein production in the animal. The most commonly used substances are non steroidal, like zeranol; however, the obtained results are inconsistent, because there are differences in animal response. Several authors report an increase in daily gain of lambs treated with zeranol (Bachman et al., 1993; Prado, 2002), while others (Field et al., 1993; Nasahlai et al., 2002; Canul et al., 2009) did not observe a positive effect on lamb performance. For these reasons, it is essential to generate additional information that explains the response of sheep to the use of non-steroidal anabolics. This study was carried out to evaluate average daily gain, feed efficiency, carcass characteristics and muscle development of hair lambs treated with zeranol.
Mostrar mais

5 Ler mais

bor 29 1 BOR 2015vol290042

bor 29 1 BOR 2015vol290042

torque (IT) and removal torque (RT) values were recorded in N.cm. Loss of torque (LT) values were obtained by calculating the difference between the IT and RT. MI mobility was measured by means of a Periotest assessment. Normality and homogeneity were determined by means of the Kolmogorov-Smirnov and Shapiro-Wilk tests, respectively. A two-way ANOVA was used to detect differences between the mini-implant design and density factors. The ANOVA/ Tukey tests were used to determine the intergroup difference. Higher IT values were observed for G 2 (p ≤ 0.05) in D 2 . No statistical difference
Mostrar mais

6 Ler mais

Correlation between index panoramic radiomorfometric and primary stability of implants

Correlation between index panoramic radiomorfometric and primary stability of implants

In Dentistry, the use of panoramic x-rays is one of the most used radiographic techniques to initially evaluate the patient. This happens because all teeth and supporting structures can be seen in a single film, applying a simple technique with a relative low dose of radiation. In such radiographs, it is possible to carry out measurements which are named radiomorphometric indexes, being described as measurements associated and correlated with the systemic bone mineral density of patients [8]. One of these indexes is called mentual index (MI), described as having a correlation with the bone mineral density of the lumbar spine and the proximal femur [9]. The MI can be measured using a high precision caliper or, digitally, by a computer program [10].
Mostrar mais

6 Ler mais

Biomechanical and histological evaluation of hydrogel implants in articular cartilage

Biomechanical and histological evaluation of hydrogel implants in articular cartilage

Male Wistar rats (~200 g) were anesthe- tized by ether inhalation. The knee joint was accessed by a medial parapatellar incision and a cylindrical hole 2 mm deep x 2.5 mm in diameter was made in the intercondylar re- gion of the femur. The orifice was washed with saline solution, and a sample of hydro- gel of the same size as the orifice was im- planted in the left knee while the control orifice in the right knee remained empty. The animals were divided into five groups of five animals per group and were observed 3, 5, 8, 12 and 16 weeks after the operation.

6 Ler mais

EFFECT OF PLATFORM SWITCHING ON MARGINAL BONE RESORPTION AROUND THE IMPLANT

EFFECT OF PLATFORM SWITCHING ON MARGINAL BONE RESORPTION AROUND THE IMPLANT

evaluated the microgap of the Branemark 2-stage implant and found that inflamed connective tissue existed 0.5 mm above and below the abutment-implant connection which resulted in 0.5 mm bone loss within 2 weeks after the abutment was connected to the implant. Additionally, Berglundh and Lindhe (1996) and Ericsson et al. (1995) observed in histologic sections of crestal bone and soft tissue that crestal bone is always separated from the base of the abutment inflammatory zone by an approximate 1 mm- wide zone of healthy connective tissue, as depicted in Fig 7. This was further demonstrated when radiologic investigations in animals and humans showed that the first bone-to-implant contact is always established at a certain vertical distance apical to the microgap, regardless of the initial vertical position of the microgap with respect to the surrounding bone level (Astrand et al 2004, Cochran et al 2009, Weng et al 2011)
Mostrar mais

60 Ler mais

João Bastos de Miranda

João Bastos de Miranda

1.3 Palavras-chave: alveolar distraction osteogenesis; distraction implants; vertical distraction; alveolar ridge augmentation; dental implants; osteogenic distraction; distractor imp[r]

24 Ler mais

Evaluation of the biocompatibility of root canal sealers using subcutaneous implants

Evaluation of the biocompatibility of root canal sealers using subcutaneous implants

he purpose of this study was to evaluate in vivo the biocompatibility of Endométhasone, Pulp Canal Sealer EWT and AH- Plus root canal sealers after implantation in rat connective tissue. Twenty-four Wistar-Furth rats were used. Polyethylene tubes were filled with the sealers and implanted into specific dorsal subdermal tissue sites of the rats. Implants were removed after 3, 7 and 30 days, fixed and processed for glycol methacrylate-embedding technique to be examined microscopically. On the 3rd day, there was a mild inflammatory reaction to Pulp Canal Sealer EWT implants, but a severe response to the other sealers with presence of acute inflammatory cells. On the 7th day, tissue organization was more evident with attenuation of the inflammatory reaction, especially for the AH-Plus implants. On the 30th day, connective tissue with few inflammatory cells was observed in contact with all sealer implants. In this time interval, the tissue in contact with Pulp Canal Sealer EWT implants was more organized, while the tissue close to Endométhasone and AH-Plus implants showed a mild persistent inflammatory reaction and had similar results to each other. In conclusion, the sealers had a similar pattern of irritation, which was more severe in the beginning and milder with time, in such a way that all sealers showed a persistent mild reaction. Pulp Canal Sealer EWT yielded better tissue organization than Endométhasone and AH-Plus, which, in turn, showed similar results to each other.
Mostrar mais

9 Ler mais

Neves Patrícia Domingues Prior

Neves Patrícia Domingues Prior

Figura 28: Resultados da Perfilometria referentes às amostras do implante HI-TEC Implants® com revestimento de TiN, do implante HI-TEC Implants® com o revestimento de Zr/ZrC[r]

116 Ler mais

Show all 10000 documents...