Evaluation of reliability of zirconia materials to be used in implant-retained restoration on the atrophic bone of the posterior maxilla: A finite element study

PURPOSE: Zirconia materials have been used for implant-retained restorations, but the stress distribution of zirconia is not entirely clear. The aim of this study is to evaluate the stress distribution and risky areas caused by the different design of zirconia restorations on the atrophic bone of the posterior maxilla. MATERIALS AND METHODS: An edentulous D4-type bone model was prepared from radiography of an atrophic posterior maxilla. Monolithic zirconia and zirconia-fused porcelain implant-retained restorations were designed as splinted or non-splinted. 300-N occlusal forces were applied obliquely. Stress analyses were performed using a 3D FEA program. RESULTS: According to stress analysis, the bone between the 1) molar implant and the 2) premolar in the non-splinted monolithic zirconia restoration model was stated as the riskiest area. Similarly, the maximum von Mises stress value was detected on the bone of the non-splinted monolithic zirconia models. CONCLUSION: Splinting of implant-retained restorations can be more critical for monolithic zirconia than zirconia fused to porcelain for the longevity of the bone.

Short implants in posterior maxilla in elderly patients: A case series

@#<p>Placement of dental implants in reduced bone in the posterior maxilla requires maxillary sinus floor elevation. However, in elderly patients this is to be avoided. A case series on the successful placement of multiple short implants in posterior maxilla and splinted crown restorations in elderly patients was presented. Long term follow up revealed survival of the implants. Short implant is a suitable treatment option for elderly patients</p>

The factors that influence postoperative stability of the dental implants in posterior edentulous maxilla / 대한악안면성형재건외과학회지

BACKGROUND: All clinicians are aware of the difficulty of installing a dental implant in posterior maxilla because of proximate position of maxillary sinus, insufficient bone width, and lower bone density. This study is to examine which factors will make the implantation in the posterior maxilla more difficult, and which factors will affect the postoperative implant stability in this region. METHODS: Five hundred seventy-three fixtures on the maxilla posterior were included for this study from all the patients who underwent an installation of the dental implant fixture from January 2010 to December 2014 at the Department of Oral and Maxillofacial Surgery in Pusan National University Dental Hospital (Yangsan, Korea). The postoperative implant stability quotient (ISQ) value, fixture diameter and length, presence of either bone graft or sinus lift, and graft material were included in the reviewed factors. The width and height of the bone bed was assessed via preoperative cone beam CT image analysis. The postoperative ISQ value was taken just before loading by using the OsstellTM mentor® (Integration Diagnostics AB, Gothenburg, Sweden). The t test and ANOVA methods were used in the statistical analysis of the data. RESULTS: Mean ISQ of all the included data was 79.22. Higher initial bone height, larger fixture diameter, and longer fixture length were factors that influence the implant stability on the posterior edentulous maxilla. On the other hand, the initial bone width, bone graft and sinus elevation procedure, graft material, and approach method for sinus elevation showed no significant impact associated with the implant stability on the posterior edentulous maxilla. CONCLUSIONS: It is recommended to install the fixtures accurately in a larger diameter and longer length by performing bone graft and sinus elevation.

Regeneração óssea na região posterior da maxila para instalação de implantes dentários / Regeneración del hueso en la región posterior del maxilar para la instalación de implantes dentales / Bone regeneration in the posterior maxillary region for installation of dental implants

Introdução: regeneração óssea da região posterior da maxila, é um recurso importante para possibilitar a localização correta dos implantes e assim permitir uma adequada reabilitação protética. Várias técnicas cirúrgicas são relatadas, desde a forma de acesso ao seio, elevação da membrana de Schneider e preenchimento da cavidade. Objetivo: abordar os recursos que vem sendo utilizados na cirurgia de regeneração óssea da região posterior da maxila bem como a efetividade dos métodos aplicados. Métodos: foi realizada uma busca eletrônica da literatura, nas bases de dados LILACS, MEDLINE e BBO de estudos publicados na língua inglesa e portuguesa. Como critérios de inclusão foram considerados artigos entre o ano 2000 e 2014, sendo que as palavras chaves que orientaram a busca foram: maxillary bone regeneration, Schneiderian membrane, maxillary sinus lift. Foram obtidos 1 529 artigos, dos quais selecionados 27 artigos relevantes para o estudo em questão. Como critérios de exclusão foram eliminados artigos no qual se encontravam no ano abaixo de 2008 e que fugiam do assunto em questão. Análises e integração da informação : encontrou-se que a técnica tradicional de acesso ao seio maxilar com uso de brocas, elevação da membrana, por meio de curetas, e a regeneração propriamente dita com enxerto ósseo autógeno e/ou heterógeno continuam como as mais utilizadas, no entanto alternativas menos invasivas como tecnologia ultrassônica para fazer acesso, hidrodissecção para elevar a membrana Schneider e biomateriais para preencher a cavidade surgem como opções viáveis e com resultados favoráveis. Conclusões: existe um direcionamento na busca por métodos e materiais que diminuam a morbidade da técnica tradicional e que ofereçam resultados satisfatórios a curto e a longo prazo. A utilização de técnicas cirúrgicas menos invasivas e uso de biomateriais estão entre os avanços para a regeneração da região posterior da maxila(AU)

Introducción: la regeneración ósea de la región posterior del maxilar es un procedimiento importante que permite la correcta colocación de los implantes dentales y una adecuada rehabilitación protésica. Se describen varias técnicas quirúrgicas que van desde la forma de acceder al seno maxilar, el levantamiento de la membrana de Schneider hasta el relleno de la cavidad. Objetivo: abordar los recursos utilizados en la cirugía de regeneración ósea de la zona posterior del maxilar y la efectividad de los métodos aplicados. Métodos: se realizó una revisión bibliográfica en las bases de datos LILACS, MEDLINE y BBO en busca de estudios publicados en inglés y portugués. El criterio de inclusion abarcó los artículos publicados entre los años 2000 y 2014 y las palabras claves que orientaron la búsqueda fueron: regeneración del hueso maxilar, membrana de Schnneider y elevación del seno maxilar. Se encontraron 1 529 artículos de los cuales se seleccionaron 27 con contenido relevante para el estudio en cuestión. En cuanto a los criterios de exclusion, se eliminaron los artículos publicados antes del 2008 y que no se asociaban mucho con el tema referido. Análisis e integración de la información: se halló que la técnica tradicional de acceso al seno maxilar con el uso de brocas, el levantamaiento de la membrana de Schnneider por medio de curetas y la regeneración como tal mediante injertos óseos autógenos y/o heterógenos siguen siendo los procedimientos más utilizados. Por otra parte, alternativas menos invasivas como la tecnología del ultrasonido para lograr acceso, la hidrodisección para levantar la membrana de Schneider y el empleo de biomaterials para rellenar la cavidad emergen como opciones viables con resultados alentadores. Conclusiones: existe una orientación hacia la búsqueda de métodos y materials que disminuyan la morbilidad de las técnicas tradicionales y ofrezcan resultados satisfactorios a corto y a largo plazos. Las técnicas quirúrgicas menos invasivas y el uso de los biomateriales se encuentran entre los avances de hoy día para la regeneración de la zona posterior del maxilar(AU)

Introduction: bone regeneration of the posterior maxilla is an important feature to enable correct placement of implants and thus allow an adequate prosthetic rehabilitation. Several surgical techniques are reported, since the form of access to the sinus, elevation of Schneider membrane and fill the cavity. Objective: to address the resources used in bone regeneration surgery of the posterior maxilla and the effectiveness of the methods applied. Methods: an electronic search of the literature was performed in the databases LILACS, MEDLINE and BBO studies published in English and Portuguese. The inclusion criteria were considered articles between 2000 and 2014, with the key words that guided the search were: maxillary bone regeneration, Schneiderian membrane, maxillary sinus lift. 1 529 articles were obtained, of which 27 selected articles relevant to the study. Exclusion criteria were eliminated in the articles which were in the year below 2008 and fleeing the matter at hand. Data analysis and integration: it was found that the traditional technique of access to the maxillary sinus with the use of drills, lifting the membrane through curettes, and the regeneration itself with autogenous bone graft and/or heterogeneous continue as the most commonly used, however alternative as less invasive ultrasonic technology to access, hydrodissection to raise the Schneider membrane and biomaterials to fill the cavity emerge as viable, with favorable results options. Conclusions: there is a direction in the search for methods and materials that reduce the morbidity of traditional techniques and which offer satisfactory results in the short and long term. The use of surgical techniques less invasive and use of biomaterials are among the advances for the regeneration of the posterior maxilla(AU)

CLINICAL STUDY ON KOREAN POSTERIOR MAXILLAE RELATED TO DENTAL IMPLANT TREATMENT

A Retrospective Study of Sintered Porous-Surfaced Dental Implants in Restoring the Posterior Maxilla

PURPOSE: The purpose of this retrospective report was to analyze long-term survival rate of sintered porous-surfaced dental implant (Endopore(R) Dental Implant system, Innova Corporation, Toronto, ON, Canada). METHODS: 61 partially edentulous patients were received a total of 127 Endopore dental implants in the maxilla. Of the 127 implants, 24 implants were restored with individual (ie, non-splinted) crowns, while 103 implants were splinted to other implants. Medical records and radiographs were evaluated and analyzed by the cumulative survival rate, location of implants, implants length and diameter, crown/implant ratio and whether the implant was splinted. Chi squire test was used statistically. RESULT: Of the 127 implants, 8 implants (6.3%) were removed and and cumulative survival rate was 93.7%. CONCLUSION: Endopore implants showed satisfactory results after up to 8 years function periods in the edentulous posterior maxilla.

Survival rate of the dental implants placed in posterior maxilla without sinus augmentation

PURPOSE : The purpose of this study is to evaluate 7-year survival rate of implants placed without bone graft in posterior maxilla and compare the survival rate by the age and gender of patient, length and diameter of implant, region of implant placement, bicortical engagement of fixture, and connection of prosthesis. MATERIAL AND METHODS : 78 patients (170 implants) who visited our institution from 2002 to 2007 and were followed up with panoramic view and medical records. Kaplan-Meier survival analysis and Log Rank (Mantel-Cox) test were used. RESULTS AND CONCLUSIONS : A 7-year cumulative survival rate for implants placed in posterior maxilla without sinus graft was 95.3%. The survival rate in men was 91.8%, significantly lower than 98.8% in woman.(p0.05), while the wide platform implant resulted in 85% survival rate which was statistically lower than 98.5% in regular platform. The posterior maxillary implants engaged bicortically showed 97.6% of 7-year Survival rate, comparing 88.6% in not engaged implants. The survival rate of the single implant was 91.2%, while 98.5% in splinted prosthesis. Therefore, the bicortical engagement of the fixtures and splinted prosthesis may be recommended to get a long-term survival rate in posterior maxilla.

Consideration of Transverse Movement of Posterior Maxilla in Orthognathic Surgery of Facial Asymmetry: Case Reports

When we establish treatment planning of facial asymmetry, we must predict each asymmetrical element that will be changed upon coronal, axial, sagittal plane. At the visual point, prediction of the change of coronal plane is most important. It is important difference between Rt. and Lt. mandibular angle belonging to posterior coronal plane, as well as anterior coronal plane, such as upper and lower incisor, or midline of chin point. Several methods for control bulk of mandibular angle are additional angle shaving after osteotomy, grinding contact area between proximal and distal segment for decrease the volume, or bone graft for increase the volume. But, at the point of bimaxillary surgery, transverse position of posterior maxilla is an important factor for control it. So, we would report transverse movement of posterior maxilla for decrease asymmetry on the posterior coronal plane of face, that is, asymmetry of mandibular angular portion.

A clinical study of maxillary sinus lift for dental implant