Determination of the pH of peri-implant crevicular fluid in successful and failing dental implant sites: a pilot study.

The aims of this pilot study were to assess if a standard technique which is used to determine the pH of dental plaque around natural teeth (the 'touch electrode' technique) could be modified for use to determine the pH of crevicular fluid around dental implants, and to evaluate any possible changes in the peri-implant crevicular fluid pH in successful and failing implants. pH measurements of a sample of subjects' (n=17) peri-implant crevicular fluid of both successful and failing dental implants present in the same oral cavities were performed using iridium/iridium oxide (Beetrode) electrodes with 100 microm sensing tips, connected to an Orion 720 A pH meter. The technique appeared to be satisfactory for the purpose intended. The mean pH of the successful implants was 6.80 [STD+/-0.4; 95% confidence intervals (CI), 6.50-7.0], and that for the failing dental implants was 7.20 (STD+/-0.6; 95% CI, 6.90-7.50). The results showed that the technique described could be satisfactorily used to determine the pH of peri-implant crevicular fluid at dental implant sites, and that there was a significant difference between the pH of successful and failing dental implants (P<0.05). However, the results obtained should be interpreted with caution in view of the small sample size used in this pilot study.