IN VITRO EVALUATION OF THE EFFECT OF SELANT APPLICATION AT THE INTERFACE OF A SCREWED TAPERED CONNECTION IMPLANT: MICROSCOPIC, MECHANICAL AND MICROBIOLOGICAL STUDY

 The objective of this in vitro study was to assess the effect of sealant at the interface of a screwed conical connection implant, regarding its mechanical behavior and bacterial infiltration. For this purpose, 60 conical implant-abutment sets were selected and divided into four groups (n=15): Group A, submitted to mechanical cycling without sealant; Group B, submitted to mechanical cycling with sealant; Group C, without mechanical cycling but with sealant; Group D, without mechanical cycling or sealant, but it was analyzed with scanning electron microscopy (SEM). The mechanical cycling test was performed with 500,000 cycles per sample with a load of 120 N and 2 Hz frequency at an angle of 30º. For microbiological analysis, 10 sets of each group (with mechanical cycling or not), were immersed in suspension containing Escherichia coli, and incubated at 37oC. After 14 days, the abutments were separated from the implants, the detorque forces were recorded and the presence of bacterial penetration was assessed. The remaining 5 sets of each group were cut longitudinally and analyzed, using SEM, at three points in the region of the implant-abutment interface. Mann Whitney tests were used for statistical calculations for comparisons between groups with and without sealant and between groups with and without cycling, and the paired samples Wilcoxon test for comparisons between distances. The analysis of bacterial growth was performed using Fisher’s exact test. The analyzes were performed using the R and SAS program, with a significance level of 5%. The results showed that at a distance of 500 µ, in the presence of sealant, there was a greater misfit with cycling than without cycling (p <0.05). In the absence of cycling there was a greater misfit without sealant than with sealant (p<0.05), in both distances. There was no significant difference between the distances regarding maladjustment (p> 0.05). There was no growth of Escherichia coli on the external part in the four groups. The group without sealant and with mechanical cycling showed significantly higher internal bacterial growth than the other groups (40% of the samples), p <0.05.