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1.
Proc Natl Acad Sci U S A ; 117(5): 2366-2371, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31964822

RESUMO

As a leading effort to improve the welfare of smallholder farmers, several governments have led major reforms in improving market access for these farmers through online agricultural platforms. Leveraging collaboration with the state government of Karnataka, India, this paper provides an empirical assessment on the impact of such a reform-implementation of the Unified Market Platform (UMP)-on market prices and farmers' profitability. UMP was created in 2014 to unify all trades in the agricultural wholesale markets of the state to be carried out within a single platform. By November 2019, 62.8 million metric tons of commodities valued at $21.7 billion (USD) have been traded on UMP. Employing a difference-in-differences method, we demonstrate that the impact of UMP on modal prices varies substantially across commodities. In particular, the implementation of UMP has yielded an average 5.1%, 3.6%, and 3.5% increase in the modal prices of paddy, groundnut, and maize. Furthermore, UMP has generated a greater benefit for farmers who produce higher-quality commodities. Given low profit margins of smallholder farmers (2 to 9%), the range of profit improvement is significant (36 to 159%). In contrast, UMP has no statistically significant impact on the modal prices of cotton, green gram, or tur. Using detailed market data from UMP, we analyze how features related to logistical challenges, bidding efficiency, in-market concentration, and the price discovery process differ between commodities with and without a significant price increase due to UMP. These analyses lead to several policy insights regarding the design of similar agri-platforms in developing countries.

2.
J Clin Diagn Res ; 8(1): 239-42, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24596785

RESUMO

BACKGROUND: In cement-retained implant-supported restoration it is important to gain adequate retention of definitive restoration as well as retrievability of prosthesis. The surface of the abutment, alloy of the restoration and the type of cement used influences the retention of the restoration. There is a need to analyze the influence of surface modifications of abutments on the retentive capabilities of provisional implant cements. PURPOSE OF STUDY: To compare the effect of implant abutment surface modifications on retention of implant-supported restoration cemented with polymer based cement. MATERIALS AND METHOD: Thirty solid titanium implant abutments (ADIN), 8mm height, were divided into 3 groups. Ten abutments with retentive grooves (Group I) as supplied by the manufacturer, Ten abutments milled to 20 taper circumferentially (Group II), and Ten abutments milled and air-abraded with 110 µm aluminum oxide (Group III) were used in this study. Ni-Cr coping were casted for each abutment and polymer based cement was used to secure them to the respective abutments. Using a universal testing machine at a crosshead speed of 0.5 cm/minute, tensile bond strength was recorded (N). RESULTS: Mean tensile bond strength of Group I, II and III were found to be 408.3, 159.9 and 743.8 Newton respectively. The values were statistically different from each other (p<0.001). CONCLUSION: Abutments with milled and sandblasted surface provide the highest retention followed by abutments with retentive grooves and then by abutments with milled surface when cast copings were cemented to implant abutments with polymer based cement. CLINICAL IMPLICATIONS: Retention of restoration depends on the surface of the abutment as well as the luting agents used. Incorporation of retentive grooves or particle abrasion can enhance retention especially in situation of short clinical crown.

3.
Int J Oral Maxillofac Implants ; 25(1): 38-44, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20209185

RESUMO

PURPOSE: The aim of the present study was to compare the accuracy of casts obtained from nonsplinted and splinted direct impression techniques employing various splinting materials for multiple dental implants. MATERIALS AND METHODS: A reference model with four Nobel Replace Select implant replicas in the anterior mandible was fabricated with denture base heat-curing acrylic resin. Impressions of the reference model were made using polyether impression material by direct nonsplinted and splinted techniques. Impressions were divided into four groups: group A: nonsplinted technique; group B: acrylic resin-splinted technique; group C: bite registration addition silicone-splinted technique; and group D: bite registration polyether-splinted technique. Four impressions were made for each group and casts were poured in type IV dental stone. Linear differences in interimplant distances in the x-, y-, and z-axes and differences in interimplant angulations in the z-axis were measured on the casts using a coordinate measuring machine. RESULTS: The interimplant distance D1y showed significant variations in all four test groups (P = .043), while D3x values varied significantly between the acrylic resin-splinted and silicone-splinted groups. Casts obtained from the polyether-splinted group were the closest to the reference model in the x- and y-axes. In the z-axis, D2z values varied significantly among the three test groups (P = .009). Casts from the acrylic resin-splinted group were the closest to the reference model in the z-axis. Also, one of the three angles measured (angle 2) showed significant differences within three test groups (P = .009). Casts from the nonsplinted group exhibited the smallest angular differences. CONCLUSION: Casts obtained from all four impression techniques exhibited differences from the reference model. Casts obtained using the bite registration polyether-splinted technique were the most accurate versus the reference model, followed by those obtained via the acrylic resin-splinted, nonsplinted, and bite registration addition silicone-splinted techniques.


Assuntos
Implantação Dentária Endo-Óssea , Materiais para Moldagem Odontológica , Técnica de Moldagem Odontológica , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Registro da Relação Maxilomandibular , Resinas Acrílicas , Análise de Variância , Humanos , Polivinil , Siloxanas , Contenções
4.
J Oral Implantol ; 35(6): 295-9, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20017646

RESUMO

This article describes the rehabilitation of a completely edentulous patient using a milled titanium implant framework and cemented crowns. This combined approach significantly offsets unsuitable implant position, alignment, or angulation, while ensuring the easy retrievability, repair, and maintenance of the prosthesis. Hence, the dual advantage of cemented-retained crowns reproducing appropriate esthetics and function, irrespective of where the screw access openings are located in the substructure, can be obtained, along with the splinting effect and management of soft and hard tissue deficits achievable with a screw-retained framework.


Assuntos
Desenho Assistido por Computador , Coroas , Implantes Dentários , Prótese Dentária Fixada por Implante , Boca Edêntula/cirurgia , Adulto , Aumento do Rebordo Alveolar/métodos , Transplante Ósseo , Cimentação/métodos , Dente Suporte , Materiais Dentários/química , Planejamento de Prótese Dentária , Revestimento de Dentadura , Feminino , Seguimentos , Humanos , Ligas Metalo-Cerâmicas/química , Boca Edêntula/reabilitação , Titânio/química
6.
J Prosthodont ; 17(4): 336-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18266653

RESUMO

Orofacial defects can be either congenital or acquired. Rehabilitation of these patients can be done using a surgical and/or a prosthetic approach. In situations where surgical reconstruction is not possible, prosthetic management becomes the only option. This clinical report describes a simple, economical, and effective technique for the prosthetic rehabilitation of a patient with oro-cutaneous fistula due to donor site dehiscence following tumor defect reconstruction.


Assuntos
Fístula Cutânea/reabilitação , Face , Fístula Bucal/reabilitação , Desenho de Prótese , Procedimentos Cirúrgicos Reconstrutivos/efeitos adversos , Transplante de Pele/efeitos adversos , Resinas Acrílicas/química , Idoso , Carcinoma de Células Escamosas/cirurgia , Feminino , Humanos , Soalho Bucal/cirurgia , Neoplasias Bucais/cirurgia , Propriedades de Superfície , Deiscência da Ferida Operatória/reabilitação , Neoplasias da Língua/cirurgia
7.
Indian J Dent Res ; 18(4): 190-5, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17938497

RESUMO

STATEMENT OF PROBLEM: The use of osseointegrated implants as a foundation for the prosthetic replacement of missing teeth has become widespread in the last decade. Owing to the remarkable success of dental implants, there has been growing interest in identifying the factors associated with implant failure. Given the well-documented deleterious effect of smoking on wound healing after tooth extraction and its association with poor quality bone and periodontal disease, a negative effect of tobacco use on implant success is to be expected. PURPOSE: To establish the relationship between smoking and implant-related surgical procedures (i.e, sinus lift procedures, bone grafts and dental implants), including the incidence of complications related to these procedures and the long-term survival and success rates of dental implants among smokers and nonsmokers based on relevant literature. MATERIALS AND METHODS: Relevant clinical studies published in English between 1990 and 2006 were reviewed. The articles were located through Medline and, manually, through the references of peer-reviewed literature. This was supplemented with a hand search of selected dental journals and text books. RESULTS: The majority of the past and current literature implicates smoking as one of the prominent risk factors affecting the success rate of dental implants with only a handful of studies failing to establish a connection. Most of the studies report the failure rate of implants in smokers as being more than twice that in nonsmokers. These findings are difficult to ignore. There is a statistically significant difference between smokers and nonsmokers in the failure rates of dental implants. Smoking also has a strong influence on the complication rates of implants: it causes significantly more marginal bone loss after implant placement, it increases the incidence of peri-implantitis and affects the success rates of bone grafts. The failure rate of implants placed in grafted maxillary sinuses of smokers is again more than twice that seen in nonsmokers. CONCLUSION: Smokers have higher failure rates and complications following dental implantation and implant-related surgical procedures. The failure rate of implants placed in grafted maxillary sinuses of smokers is more than twice that seen in nonsmokers.


Assuntos
Implantes Dentários , Fumar , Falha de Restauração Dentária , Humanos , Osseointegração/fisiologia , Complicações Pós-Operatórias , Fatores de Risco , Fumar/efeitos adversos , Resultado do Tratamento
8.
J Oral Implantol ; 31(3): 121-8, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16001685

RESUMO

Although many improvements have been made to implant dentistry during the last quarter of a century, clinical challenges still remain. For the surgeon, achieving implant stability in low-density bone can be difficult. For the restorative dentist, incompatibility between implant systems and the increasing complexity of esthetic restorative options frequently require special training in the selection and use of prosthetic components. This article presents an overview of a 1-stage implant system with a textured surface and osteocompressive surgical protocol designed to achieve stability in soft bone. Self-tapping, double lead threads and a separate surgical protocol also enable the implant to be placed in high-density bone. The implant is packaged on a fixture mount that also functions as a transfer and transitional or definitive abutment for cemented restorations. This implant is designed to help simplify restorative procedures by eliminating many ancillary restorative components. For multiple-unit, screw-retained restorations, the prosthesis can be splinted directly to the top of the implant without an intermediate abutment. Overdenture attachments and straight, angled, screw-receiving, and custom-cast abutments complete the restorative system.


Assuntos
Implantação Dentária Endo-Óssea/instrumentação , Implantes Dentários , Retenção em Prótese Dentária/métodos , Implantação Dentária Endo-Óssea/métodos , Planejamento de Prótese Dentária , Humanos , Propriedades de Superfície
9.
J Prosthet Dent ; 92(6): 578-80, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15583566

RESUMO

The advantages of cement-retained implant-supported restorations over screw-retained implant restorations are well documented. Difficulty with prosthesis retrieval and excess cement removal may be experienced with cemented restorations. The technique described allows for the fabrication of a retrievable cemented prosthesis that is simple, practical, and effective.


Assuntos
Cimentação/métodos , Coroas , Retenção em Prótese Dentária/instrumentação , Retenção em Prótese Dentária/métodos , Prótese Dentária Fixada por Implante , Humanos , Tecnologia Odontológica/métodos
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