SHORT COMMUNICATION Determination of the pH of peri-implant crevicular fluid in successful and failing dental implant sites: A pilot study E.A. Nyako, C.J. Watson, A.J. Preston * Leeds Dental Institute, Leeds, UK Accepted 10 March 2005 Introduction Although high success rates have been reported for many dental implant systems, 1 failures leading to dental implant loss still occur. Esposito et al. 2 reported an overall failure rate for the ‘Branemark’ dental implant system (Nobel Biocare, Go ¨tenborg, Sweden) of 7.7% over a 5-year period. They also noted failure rates for maxillary and mandibular implants of 10 and 3%, respectively, while 4% of implants were lost in par- tially dentate patients. Fiorellini et al. 1 also reported comparable failure rates in other implant systems. The search for reliable methods of early detection of dental implant failure, to enable quick interven- tion, is ongoing. Electronic devices such as the ‘Peri- otest’ 3 and the ‘Periotron 6000’ 4 have been used to assess the degree of osseiointegration and gingival Archives of Oral Biology (2005) 50, 1055—1059 www.intl.elsevierhealth.com/journals/arob KEYWORDS Dental implant; pH; Peri-implant; Crevicular fluid Summary 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 1 ) electrodes with 100 mm 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 Æ 0.4; 95% confidence intervals (CI), 6.50— 7.0], and that for the failing dental implants was 7.20 (STD Æ 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. # 2005 Elsevier Ltd. All rights reserved. * Corresponding author at: Liverpool University Dental Hospital, School of Dentistry, Pembroke Place, Liverpool L3 5PS, UK. Tel.: +44 151 706 5218; fax: +44 151 706 5845. E-mail address: a.j.preston@liv.ac.uk (A.J. Preston). 0003–9969/$ — see front matter # 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.archoralbio.2005.03.011