Bone density and implant stability with advanced platelet-rich fibrin in immediately loaded- implant assisted mandibular overdentures / Densidade óssea e estabilidade dos implantes com fibrina rica em plaquetas avançada em overdentures mandibulares com carga imediata

ABSTRACT Objective: The aim of this study is to determine the effect of Advanced Platelet-Rich Fibrin on bone density and implant stability in immediately loaded- implant-assisted mandibular overdentures (Split-mouth study). Material and Methods: Ten completely edentulous patients received two implants in the mandibular canine region and locator attachments were used to retain immediately loaded- implant mandibular overdentures. Each patient served in two Groups, one Group for each side. One side of the mandible received an implant with topical application of Advanced Platelet-Rich Fibrin in the implant osteotomy site (Group I) and the other site received an implant without application of Advanced platelet-rich fibrin (Group II). Each patient was examined clinically for implant stability using Osstell Mentor device and radiographically by ultra-low dose CT scan to measure bone density around the implant at baseline, three, six months, and one year. Results: There were no statistically significant differences (P>.05) in bone density and implant stability among the studied Groups during one year follow-up period. Conclusion : Advanced Platelet-Rich Fibrin has no effect on bone density and implant stability in immediately loaded implant-assisted mandibular overdenture.(AU)

RESUMO Objetivo: O objetivo deste estudo é determinar o efeito da Fibrina Rica em Plaquetas Avançada na densidade óssea e estabilidade dos implantes em Overdentures mandibulares com carga imediata (estudo de boca dividida). Material e Métodos: Dez pacientes edêntulos foram submetidos à instalação de dois implantes mandibulares na região dos caninos e pilares locator foram utilizados como sistema de retenção para as overdentures mandibulares com carga imediata. Cada paciente participou nos dois grupos, sendo um grupo para cada lado. Um lado da mandíbula recebeu implante com aplicação tópica de Fibrina Rica em Plaquetas Avançada no local do sítio cirúrgico do implante (Grupo I) e o outro local recebeu implante sem aplicação de Fibrina Rica em Plaquetas Avançada (Grupo II). Cada paciente foi examinado clinicamente quanto à estabilidade do implante usando o dispositivo Osstell Mentor e radiograficamente por tomografia computadorizada de ultrabaixa dose para medir a densidade óssea ao redor do implante no início do estudo, três, seis meses e um ano. Resultados: Não houve diferenças estatisticamente significativas (P>0,05) na densidade óssea e na estabilidade do implante entre os grupos estudados durante o período de acompanhamento de um ano. Conclusão: A Fibrina Rica em Plaquetas Avançada não tem efeito na densidade óssea e na estabilidade de implantes em Overdentures mandibulares com carga imediata (AU)

Sobredentadura parcial como alternativa de tratamiento en paciente con secuela periodontal. Reporte de caso

La rehabilitación de pacientes desdentados parciales periodontalmente comprometidos es un desafío a nivel protésico. Esto se debe a que la condición de los dientes pilares no siempre es la adecuada, viéndose afectada la proporción corono-radicular por las secuelas de una enfermedad periodontal. Es en estas situaciones límite donde el uso de implantes óseo-integrados acompañado de ataches resilientes mejora la retención de una prótesis parcial removible convencional, disminuyendo el riesgo de sobrecarga en los dientes remanentes. En este reporte de caso se presenta una rehabilitación integral, resuelto con una sobredentadura parcial maxilar sin cobertura palatina sobre pilares Locator®, minimizando la carga en los dientes remanentes del grupo II con secuelas periodontales; y una rehabilitación del arco mandibular con operatoria directa, indirecta y prótesis fija, recuperando funcionalidad, soporte oclusal y manteniendo los dientes remanentes en el sector anterior.

Rehabilitation of periodontally compromised partially edentulous patients has always been a challenge at the prosthetic level, because the condition of the remaining teeth is not always adequate and the crown-root ratio is often affected by the sequelae of periodontal disease. In these borderline situations, the use of osseointegrated implants accompanied by resilient attachments improves the retention of a conventional removable partial denture, reducing the risk of overloading the remaining teeth. This case report presents a comprehensive rehabilitation, resolved with a maxillary partial overdenture without palatal coverage on Locator® abutments, minimizing the load on the remaining pieces of group II with periodontal sequelae; and a rehabilitation of the mandibular arch with direct, indirect and fixed prosthesis. In this way, it was possible to recover functionality, occlusal support and keep the remaining teeth in the front part of the maxilla.

Rehabilitation of mandibular edentulous patients with a few unilateral remaining teeth using implant-assisted removable partial denture: A case report / 대한치과보철학회지

In the case of a patient with a small number of unilateral remaining teeth in the mandible, a restoration with conventional removable partial denture cannot provide sufficient retention and resistance. A harmful stress from the poor stability of denture on remaining teeth occurs due to alveolar bone resorption in edentulous area. Although implant fixed prosthesis can provide multiple benefits over conventional removable partial denture, there are limitations come from anatomic structures and costs. In this case, an implant-assisted removable partial denture (IARPD) with a couple of implants placed in strategic positions can be a treatment modality. The objective of this article is to present a case report of two patients showed satisfactory clinical outcomes during three-year follow-up period describing the fabrication and advantages of removable partial denture assisted by teeth and implants (IARPD) for a patient with a small number of unilateral remaining teeth in mandible using Locator as an implant attachment.

Effect of implant- and occlusal load location on stress distribution in Locator attachments of mandibular overdenture. A finite element study

PURPOSE: The aim of this study is to evaluate and compare the stress distribution in Locator attachments in mandibular two-implant overdentures according to implant locations and different loading conditions. MATERIALS AND METHODS: Four three-dimensional finite element models were created, simulating two osseointegrated implants in the mandible to support two Locator attachments and an overdenture. The models simulated an overdenture with implants located in the position of the level of lateral incisors, canines, second premolars, and crossed implant. A 150 N vertical unilateral and bilateral load was applied at different locations and 40 N was also applied when combined with anterior load at the midline. Data for von Mises stresses in the abutment (matrix) of the attachment and the plastic insert (patrix) of the attachment were produced numerically, color-coded, and compared between the models for attachments and loading conditions. RESULTS: Regardless of the load, the greatest stress values were recorded in the overdenture attachments with implants at lateral incisor locations. In all models and load conditions, the attachment abutment (matrix) withstood a much greater stress than the insert plastic (patrix). Regardless of the model, when a unilateral load was applied, the load side Locator attachments recorded a much higher stress compared to the contralateral side. However, with load bilateral posterior alone or combined at midline load, the stress distribution was more symmetrical. The stress is distributed primarily in the occlusal and lateral surface of the insert plastic patrix and threadless area of the abutment (matrix). CONCLUSION: The overdenture model with lateral incisor level implants is the worst design in terms of biomechanical environment for the attachment components. The bilateral load in general favors a more uniform stress distribution in both attachments compared to a much greater stress registered with unilateral load in the load side attachments. Regardless of the implant positions and the occlusal load application site, the stress transferred to the insert plastic is much lower than that registered in the abutment.

Full mouth rehabilitation of a partially edentulous patient with crossed occlusion using implant-retained RPD with zirconia occlusal table

Conventional removable partial dentures (RPDs) with distal extensions are associated with some problems, including lack of stability that calls for frequent relining, and cantilever actions of claps that can produce excessive loading to abutment teeth, and the need for unesthetic retentive arm clasps. Therefore, IARPDs (Implant-assisted RPD) that use implants to support or retain RPDs has been reported to improve stability, esthetics and masticatory performance of RPDs. Also, an IARPD that has zirconia occlusal table can prevent the incongruity of occlusal plane and the extrusion of antagonistic tooth. In this case of partially edentulous patient with crossed occlusion, each edentulous area was restored with implant fixed prosthesis and implant retained partial denture to suit each situation. Through the procedure, satisfactory outcomes were achieved both in functional and esthetic aspects.

Clinical evaluation of implant retained overdentures using two implant and Locator attachments in the fully edentulous mandibles / 대한치과보철학회지

PURPOSE: This study compared the marginal bone loss around dental implant that were placed in the canine areas of the mandibles and finded the survival rate of implants, marginal bone loss around implants and prosthetic complications in 10 patients treated with overdentures retained with Locator attachments. MATERIALS AND METHODS: Ten patients who had received implant retained overdentures in the mandibules using two implants and Locator attachments at Daegu Catholic University Medical Center from 2004 to 2010 were included in this study. Evaluations of the survival rate of implants, marginal bone loss and prosthetic complications were performed. RESULTS: Implants placed in this study showed a 100% survival rate and the average annual bone loss was 1.03 mm +/- 0.20 mm in the first year. The patients have verbally indicated that they are comfortable and that their overdentures function well. But, implant retained overdentures had various prosthetic complications such as male change, relining, rebasing and denture fracture. CONCLUSION: Implant retained overdentures using two implant and Locator attachments in the fully edentulous mandibles is considered as a stable way for long terms because of minimal invasive operation, simple prosthetic process and easy repair.