Full text
| |
| Author(s): |
Antônio Pedro Ricomini Filho
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | Alto, Piracicaba, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba |
| Defense date: | 2009-04-12 |
| Examining board members: |
Altair Antoninha Del Bel Cury;
Fernando Faot;
Livia Maria Andaló Tenuta
|
| Advisor: | Altair Antoninha Del Bel Cury |
| Abstract | |
The presence of microorganisms in the implant and abutment interface is one of the factors associated to the osseointegrated implant failures. Conical junction implant systems have aimed a precise fit between implant and abutment, however, the behavior of these systems it is not known when submitted to the stress environment as found in the oral cavity, related to the preload maintenance and bacterial seal ability. Thus, the aim of this study was to evaluate the preload loss and the bacterial penetration through the implant-abutment interface of conical and external hexagon connection systems, submitted to thermal cycling and mechanical fatigue (TM). Forty eight implants of four different implant-abutment systems were divided in 8 groups (n=6): (1) external hexagon and universal post; (2) external hexagon and universal post with TM; (3) morse taper and universal post; (4) morse taper and universal post with TM; (5) morse taper and universal post two pieces; (6) morse taper and universal post two pieces with TM; (7) locking taper and standard abutment; (8) locking taper and standard abutment with TM. The implants were embedded in epoxy resin and the abutments were connected, setting the preload. The assemblies (implant-abutment) were submitted to thermal cycling of 1.000 cycles at 5°C and 55°C, with a dwell time of 60 s each and to mechanical fatigue, 1.0 million cycles, 1.0 Hz, 120 N. Bacterial penetration assay was performed with Streptococcus sanguinis (NCTC 10904). The assemblies were immersed in Tryptic Soy + Yeast Extract (TY) broth containing S. sanguinis and incubated at 37°C and 10% CO2 for 72 h. Detorque values were recorded and the abutments were disconnected. Sterile paper points were rubbed on the inner part of the implant and inserted in a tube with sterile TY broth and incubated. The presence or absence of bacterial penetration was assessed by the broth turbidity. Implants and abutments were observed by SEM. The preload loss data was analyzed by two-way ANOVA, followed by Tukey test. All the screw systems showed higher detorque values when submitted to TM(p<0,05). The morse taper system with universal post showed the highest detorque values when compared with the other systems (p<0,01). All the conical systems showed bacteria penetration. Within these experimental conditions, the morse taper system with universal post showed the higher detorque values and no relation between the preload loss and the bacterial penetration was observed. (AU) | |