Gingival crevicular fluid alkaline phosphatase activity reflects periodontal healing/recurrent inflammation phases in chronic periodontitis patients.

Background: Roles for host enzymes as diagnostic indicators of periodontal status in gingival crevicular fluid (GCF) have been proposed. One of these host enzymes is alkaline phosphatase (ALP), the GCF activity of which has been associated with periodontal inflammation. Thus, the present study aimed to improve our understanding of how the healing of chronic periodontitis following scaling and root planing (SRP) affects GCF ALP activity after 15 and 60 days.
Methods: Sixteen systemically healthy subjects (aged 35 to 61 years) with moderate to advanced generalized chronic periodontitis were recruited. In each subject, paired pockets with probing depths (PDs) > or =4 mm that were located in two symmetric quadrants were chosen. These sites were randomized at the split-mouth level, with half receiving SRP treatment and the other half left untreated. Ninety-two pockets were included in the study. Clinical examinations were performed at baseline (prior to SRP) and after 15 and 60 days; information recorded included the presence of plaque, PD, clinical attachment level (CAL), and bleeding on probing. GCF was collected from each pocket included in the study at the three time points.
Results: A large and significant decrease in GCF ALP activity was seen 15 days after SRP, concomitant with an improvement in clinical parameters. After 60 days, an increase in GCF ALP activity back to baseline levels was recorded along with further improvements in clinical parameters. Moreover, in the SRP pockets with initial PDs >6 mm, the CAL gains between days 15 and 60 were significantly associated with changes in GCF ALP activity over the same time interval.
Conclusions: The decrease in GCF ALP activity at 15 days corresponded to a decrease in clinical signs of inflammation; in contrast, the increase in GCF ALP activity at 60 days seemed to be related to subclinical recurrent inflammation or further healing/remodeling of the periodontal tissue. Therefore, GCF ALP reflects the short-term periodontal healing/recurrent inflammation phases in chronic periodontitis patients.