Clinicians have described the success rates of dental implants. The use of implants is projected to increase in the future. With a 5-10% failure rate, it is unclear the exact factors that are associated with implant failures. To improve upon these success rates, it is critical to understand parameters associated with implant failure including: periodontitis, peri-implantitis, systemic diseases, site preparation, dental history of the implant site, bone quality, materials, occlusion, and treatment timelines. While bone quality is associated with failure, objective measures to assess bone quality and characteristics are scarce. Therefore, the aim of this study is to determine whether possible comorbidities, associated dental parameters, and measurable bone quality are possible predictors of implant failure. In this study, we utilized the electronic health record system axiUm® to retrospectively investigate non-failed (NF) and failed (F) dental implants from a patient cohort with 149 implants placed between 2012-2015 at Virginia Commonwealth University School of Dentistry. A chart review was conducted extracting information on age, gender, systemic diseases, smoking, occlusal trauma, parafunction, bone grafting history, treatment timelines, implant site/type/placement protocol, infection, torque at placement, bone quality and microarchitecture assessed by the novel, innovative technology: trabecular bone score (TBS). A total of 149 implants, 46 failures and 105 non-failed controls, were selected based on similar implant sites. Preliminary data obtained from analysis suggests that average time from implant placement to failure was 6.6 months (0.55 years). Parafunction habit (p=0.0202) and increased number of implants (p=0.0478) were found to be associated with increased implant failure.

O objetivo desse estudo foi avaliar as taxas de sobrevida de implantes unitários, instalados na maxila, com diferentes tratamentos de superfícies: oxidação anódica (AO), duplo ataque ácido (DAE), ataque ácido e jateamento (SAE) e ataque ácido e jateamento modificada (SAE modificada). Também avaliou a influência de outras variáveis sobre estas taxas. Foram avaliados pacientes com implantes unitários em maxila, atendidos no Centro Odontológico da Polícia Militar de São Paulo e do Centro de Excelência em Prótese e Implantes da Universidade de São Paulo (Brasil), entre janeiro de 2008 e julho de 2013. Os seguintes dados foram coletados: sexo do paciente, características do implante (forma, diâmetro, comprimento), tratamento de superfície, localização do implante (maxila anterior ou posterior), presença de enxerto ósseo e falhas de implantes. O desfecho primário foi a perda do implante (falha). Estatísticas descritivas foram realizadas para caracterizar a distribuição de frequência de implantes em relação às variáveis. A análise da falha do implante foi feita por curvas de sobrevida de Kaplan-Meier. O teste de Mantel-Cox identificou as variáveis associadas à falha do implante ao longo do tempo. A amostra analisada foi constituída por 1076 implantes em 549 pacientes. As falhas ocorreram em 20 implantes (1,9%), 15 deles (75%) em homens e 5 em mulheres (25%). A frequência de falha foi maior em regiões de enxerto ósseo, e esta diferença ocorreu nos implantes em homens e com superfície DAE. A presença de enxerto aumentou em seis vezes as chances de falha do implante em relação às áreas de osso natural. Nos pacientes com implantes com superfície DAE estimou-se que essa chance de falha do implante em área de enxerto aumentou em nove vezes. / The purpose was evaluate the survival rates of single implants installed in maxilla with different surface treatments: anodic oxidation (AO), dual acid-etching (DAE), sandblasted and acid-etched (SAE) e sandblasted and acid-etched modified (SAE modified). It also evaluated the influence of other variables on these rates. Patients with installed single implants in the maxilla treated at Dental Center of Military Police of São Paulo and the Center for Excellence in Prosthodontics and Implants of the University of São Paulo (Brazil) between January 2008 and July 2013 were evaluated. The following data were collected: patient gender, implant characteristics (shape, diameter, length), surface treatment, location of the implant (anterior or posterior maxilla), presence of bone graft and implant failures. The primary outcome was the loss of the implant (failure). Descriptive statistics were used to characterize the frequency distribution of implants in relation to the variables. The analysis of implant failure was made by survival curves of Kaplan-Meier. The Mantel-Cox test was performed to identify variables associated with implant failure over time. The sample consisted of 1076 implants in 549 patients. Failures occurred in 20 implants (1.9%), while 15 of them (75%) were men and 5 women (25%). The frequency of failure was higher in regions of bone graft, and this difference was related to implants in men and in DAE implants. The presence of graft area increased by 6 times the chances of implant failure in relation to areas of natural bone. In DAE implants was estimated that the chance of failure of the implant graft area increased by 9 times.

<p>In two prospective, clinical studies the stability of implants and prosthetic constructions were evaluated after three years of loading. In the first study, the implant and the bridge stability of 39 patients with 1-stage bone grafts, were compared to a reference-group of 37 patients who did not need bone grafts. In the second study, 40 patients were randomised to have either 1-stage sinus inlay bloc grafts or 2-stage sinus inlay particulated grafts. </p><p>Implant success in Paper 1, was 75.3% in the study group and 93.1% in the reference group. In Paper 2 implant survival in the 1-stage group was 77.7% and 86.5% in the 2-stage group. Bruxism and post-operative complications, such as unexpected pain, dehiscence and infection were found to be associated with the later loss of implants. </p><p>The volumes of onlay block and inlay particulated bone grafts, after 6 months as evaluated by computed tomography showed the decrease of 49.5% and 47% respectively, although there was a wide range in both groups. </p><p>Using of cutting torque measurements during the placement of implants in grafted and non-grafted jaw bone, showed a significant inverse correlation to the commonly used clinical estimation of jaw bone quality, acc. to Lekholm & Zarb. Significantly lower torque values were recorded in grafted regions when compared to non-grafted. </p><p>It was shown that autogenous bone grafts and implants to the edentulous maxilla, after early high failure rates, showed stable and predictable results after three years. Bruxism was found to be significantly associated with implant failures and initially reduced biomechanical properties was seen in the grafted bone. </p>

In two prospective, clinical studies the stability of implants and prosthetic constructions were evaluated after three years of loading. In the first study, the implant and the bridge stability of 39 patients with 1-stage bone grafts, were compared to a reference-group of 37 patients who did not need bone grafts. In the second study, 40 patients were randomised to have either 1-stage sinus inlay bloc grafts or 2-stage sinus inlay particulated grafts. Implant success in Paper 1, was 75.3% in the study group and 93.1% in the reference group. In Paper 2 implant survival in the 1-stage group was 77.7% and 86.5% in the 2-stage group. Bruxism and post-operative complications, such as unexpected pain, dehiscence and infection were found to be associated with the later loss of implants. The volumes of onlay block and inlay particulated bone grafts, after 6 months as evaluated by computed tomography showed the decrease of 49.5% and 47% respectively, although there was a wide range in both groups. Using of cutting torque measurements during the placement of implants in grafted and non-grafted jaw bone, showed a significant inverse correlation to the commonly used clinical estimation of jaw bone quality, acc. to Lekholm &amp; Zarb. Significantly lower torque values were recorded in grafted regions when compared to non-grafted. It was shown that autogenous bone grafts and implants to the edentulous maxilla, after early high failure rates, showed stable and predictable results after three years. Bruxism was found to be significantly associated with implant failures and initially reduced biomechanical properties was seen in the grafted bone.

O objetivo desse estudo foi avaliar as taxas de sobrevida de implantes unitários, instalados na maxila, com diferentes tratamentos de superfícies: oxidação anódica (AO), duplo ataque ácido (DAE), ataque ácido e jateamento (SAE) e ataque ácido e jateamento modificada (SAE modificada). Também avaliou a influência de outras variáveis sobre estas taxas. Foram avaliados pacientes com implantes unitários em maxila, atendidos no Centro Odontológico da Polícia Militar de São Paulo e do Centro de Excelência em Prótese e Implantes da Universidade de São Paulo (Brasil), entre janeiro de 2008 e julho de 2013. Os seguintes dados foram coletados: sexo do paciente, características do implante (forma, diâmetro, comprimento), tratamento de superfície, localização do implante (maxila anterior ou posterior), presença de enxerto ósseo e falhas de implantes. O desfecho primário foi a perda do implante (falha). Estatísticas descritivas foram realizadas para caracterizar a distribuição de frequência de implantes em relação às variáveis. A análise da falha do implante foi feita por curvas de sobrevida de Kaplan-Meier. O teste de Mantel-Cox identificou as variáveis associadas à falha do implante ao longo do tempo. A amostra analisada foi constituída por 1076 implantes em 549 pacientes. As falhas ocorreram em 20 implantes (1,9%), 15 deles (75%) em homens e 5 em mulheres (25%). A frequência de falha foi maior em regiões de enxerto ósseo, e esta diferença ocorreu nos implantes em homens e com superfície DAE. A presença de enxerto aumentou em seis vezes as chances de falha do implante em relação às áreas de osso natural. Nos pacientes com implantes com superfície DAE estimou-se que essa chance de falha do implante em área de enxerto aumentou em nove vezes. / The purpose was evaluate the survival rates of single implants installed in maxilla with different surface treatments: anodic oxidation (AO), dual acid-etching (DAE), sandblasted and acid-etched (SAE) e sandblasted and acid-etched modified (SAE modified). It also evaluated the influence of other variables on these rates. Patients with installed single implants in the maxilla treated at Dental Center of Military Police of São Paulo and the Center for Excellence in Prosthodontics and Implants of the University of São Paulo (Brazil) between January 2008 and July 2013 were evaluated. The following data were collected: patient gender, implant characteristics (shape, diameter, length), surface treatment, location of the implant (anterior or posterior maxilla), presence of bone graft and implant failures. The primary outcome was the loss of the implant (failure). Descriptive statistics were used to characterize the frequency distribution of implants in relation to the variables. The analysis of implant failure was made by survival curves of Kaplan-Meier. The Mantel-Cox test was performed to identify variables associated with implant failure over time. The sample consisted of 1076 implants in 549 patients. Failures occurred in 20 implants (1.9%), while 15 of them (75%) were men and 5 women (25%). The frequency of failure was higher in regions of bone graft, and this difference was related to implants in men and in DAE implants. The presence of graft area increased by 6 times the chances of implant failure in relation to areas of natural bone. In DAE implants was estimated that the chance of failure of the implant graft area increased by 9 times.