Detalhes bibliográficos
| Ano de defesa: |
2016 |
| Autor(a) principal: |
Villarinho, Eduardo Aydos
 |
| Orientador(a): |
Shinkai, Rosemary Sadami Arai
|
| Banca de defesa: |
Não Informado pela instituição |
| Tipo de documento: |
Tese
|
| Tipo de acesso: |
Acesso aberto |
| Idioma: |
por |
| Instituição de defesa: |
Pontifícia Universidade Católica do Rio Grande do Sul
|
| Programa de Pós-Graduação: |
Programa de Pós-Graduação em Odontologia
|
| Departamento: |
Faculdade de Odontologia
|
| País: |
Brasil
|
| Palavras-chave em Português: |
|
| Área do conhecimento CNPq: |
|
| Link de acesso: |
http://tede2.pucrs.br/tede2/handle/tede/6922
|
Resumo: |
Short dental implants offer to dentists and patients a feasible option for prosthetic rehabilitation in cases with anatomic limitations when compared with regenerative techniques. This prospective, clinical-radiographic, cohort study aimed: in manuscript 1, to evaluate the rates of prosthetics failures, implants failures and marginal bone loss of 6-mm dental implants restored with single crowns in posterior region, and their risk factors; and 2) in manuscript 2, to present the development of a new method to measure volumetric alterations of bone level around dental implants using superimposition of 3D images. Methodology: A total of 46 implants Standard Plus Regular Neck SLActive® (Straumann), 6-mm length and 4.1-mm diameter, were installed in 20 patients. Clinical and radiographic data were collected after implant surgery, after prosthesis installation and every 12-month follow-up. Cone beam computed tomographic (CBCT) images were taken after implant surgery, and 12 and 24 months after prosthesis installation. In manuscript 1, the potential risk factors (arch, presence of bruxism, maximum bite force, clinical and anatomical crown/implant (C/I) ratios, occlusal table) were analyzed for the outcomes: implant survival, bone loss (linear) and prosthetic failures. In manuscript 2, the tridimensional images of bone perimeter closest to the implant were built using the software Mimics®, converted into the STL format, and then exported to the software Geomagic Studio®, where they were 3D-superimposed and volumetrically assessed. Results: In manuscript 1, the average time of clinical follow-up was 45 ± 9 (16; 57) months. There was no early implant loss; after prosthetic loading four implants failed (survival of 91.3%) and 13 prosthetic failures occurred (28.3%), resulting in a 65.2% success rate. The frailty model for survival analysis showed a probability of 95% implant failure in the mandible in relation to the maxilla. The average bone loss was 0.2 ± 0.4mm in the first year, 0.1 ± 0.2mm in the second year, 0.1 ± 0.3mm in the third year, and 0.2 ± 0.4mm in the fourth year, with average cumulative bone loss of 0.3 ± 0.5mm at 48 months. In the multilevel model the effects of clinical C/I ratio (P<0.001) and time (P<0.001) were significant for bone loss, estimating that an average 0.1 bone loss is associated with each increase of one unit of time (12 months) and of 0.1 of clinical C/I ratio. No other potential risk factors showed significant relation with the outcomes. In manuscript 2, the average volumetric bone loss was 7.2 ± 6.1 mm3 in the first year, 6.4 ± 7.8 mm3 in the second year, and 12.6 ± 8.0 mm3 for the cumulative period of 2 years in function. Conclusions: Within the conditions of this study, the 6-mm implants proved to be a safe alternative for oral rehabilitation. However, the mandible had higher risk of failure than the maxilla. The prosthetic complications ratio was higher than the ones reported in the literature, but all of them were repaired easily. Time and clinical C/I ratio were predictors for bone loss. However, the amount of bone loss was within the success criteria adopted. The measurement of volumetric bone alterations around implants is possible, since the CBCT images have good contrast and sharpness, particularly for the implant contour. Improvement in the quality of the images and software filters for detection of bone tissue would be important to turn this method faster and clinically useful. |
