| Full text | |
| Author(s): |
Tiossi, Rodrigo
[1]
;
Gomes, Erica Alves
[2]
;
Lapria Faria, Adriana Claudia
[2]
;
Silveira Rodrigues, Renata Cristina
[2]
;
Ribeiro, Ricardo Faria
[2]
Total Authors: 5
|
| Affiliation: | [1] Univ Fed Fluminense, Sch Dent, Dept Prosthodont, BR-24020140 Niteroi, RJ - Brazil
[2] Univ Sao Paulo, Ribeirao Preto Sch Dent, Dept Dent Mat & Prosthodont, BR-14049 Ribeirao Preto, SP - Brazil
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | JOURNAL OF PROSTHETIC DENTISTRY; v. 112, n. 4, p. 828-833, OCT 2014. |
| Web of Science Citations: | 8 |
| Abstract | |
Statement of problem. Few studies have investigated the microgap of long-span complete-arch fixed dental prosthesis zirconia frameworks. Purpose. The purpose of this study was to evaluate the effects of cyclic loading on the vertical microgap of maxillary 12-unit prostheses supported by 4 implants and on 14-unit prostheses supported by 6 implants. Material and methods. One-piece zirconia frameworks were fabricated with a computer-aided design/computer-aided manufacturing technique and divided into 2 groups (n=5): a group of 12-unit prostheses and a group of 14-unit prostheses. The vertical microgap between the frameworks and prosthetic abutments was measured with an optical microscope (80x) under 2 reading conditions. Condition 1 (1-screw test): 1A, the screw on implant 1 was tightened and readings were made on all implants; 1B, the screw was changed to implant 4 (implant 6 for the 14-unit group) and readings were made on all implants. Condition 2: the microgap was measured with all screws tightened before cyclic loading (2A). Specimens were submitted to 200 N underwater (37 C) cyclic loading at a 2-Hz frequency for 1 x 106 cycles. Microgap reading condition 2 was repeated after cyclic loading (2B). The data were submitted to a linear mixed-effects model for statistical comparison (alpha=.05). Results. A lower (P<.05) vertical microgap (mu m) was found for the 12-unit group (reading conditions: 1A, 47.93; 1B, 43.83; 2A, 11.77; and 2B, 11.25) compared to the 14-unit group (1A, 94.87; 1B, 112.56; 2A, 21.28; and 23, 16.90). No differences were found when each group was compared before and after cyclic loading (P>.05). Conclusions. The vertical microgap was significantly reduced after tightening all the screws in the framework, possibly leading to a nonpassive situation. Longer-span frameworks showed an increased microgap. Cyclic loading had no influence on the vertical microgap within each group. (AU) | |
| FAPESP's process: | 10/19221-9 - A digital image correlation analysis and non-linear 3D-FEM on the strain distribution of screwed and cemented fixed partial dentures fabricated by a CAD/CAM system in titanium and zirconia |
| Grantee: | Rodrigo Tiossi |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 10/00124-3 - Influence of mechanical cycling on loosening of retention screw in cemented and screwed fixed partial dentures fabricated with titanium and zirconia cad/cam system. In vitro analysis and non-linear analysis by 3D-FEA. |
| Grantee: | Erica Alves Gomes |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 11/01506-0 - A digital image correlation analysis and non-linear 3D-FEM on the strain distribution of screwed and cemented fixed partial dentures fabricated by a CAD/CAM system in titanium and zirconia |
| Grantee: | Ricardo Faria Ribeiro |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 10/02218-5 - Influence of mechanical cycling on loosening of retention screw in cemented and screwed fixed partial dentures fabricated with titanium and zirconia cad/cam system. In vitro analysis and non-linear analysis by 3D-FEA |
| Grantee: | Ricardo Faria Ribeiro |
| Support Opportunities: | Regular Research Grants |