Salivary P. gingivalis and PISF IL-1β in periodontally susceptible/non-susceptible individuals

Abstract

Objective: Salivary periodontal pathogens have been implicated as risk indicators for periodontal and peri-implant disease progression. This study aimed to evaluate the salivary level of P. gingivalis as a possible indicator of the proinflammatory response at periimplant mucositis affected sites in periodontally susceptible and non-susceptible cohorts. Method: 53 non-smoker subjects with peri-implant mucositis were evaluated. 26 subjects had a past history of periodontal disease (P-Group) and 27 were periodontally healthy (N-Group). One site with peri-implant mucositis and one with gingivitis was randomly selected for sampling. Sub-marginal/gingival plaque biofilm, peri-implant sulcular fluid (PISF) and whole saliva samples were collected. Real time PCR was used to quantify P. gingivalis in the saliva and plaque samples. Interleukin 1-beta (IL-1β) levels in PISF were determined using ELISA. Subjects were categorized as 'high' (5 log or more) and 'low'(less than 5 log) salivary P.gingivalis carriers and scored according to quartiles of PISF IL-1β levels. Both groups were analyzed for effects of salivary P.gingivaliscarriage on PISF IL-1β score.

Result: Salivary P.gingivalis levels were significantly correlated with the plaque levels at peri-implant and gingival niches (p<0.001). N-Group subjects with ‘high’ salivary P. gingivalis had significantly higher PISF IL-1β level than the ‘low’ carriers (p=0.035), whereas no significant difference was found in the P-Group (p=0.552).

Conclusion: This preliminary study suggests salivary P. gingivalis is indicative of its biofilm burden at peri-implant and gingival niches. Among non-periodontally susceptible subjects, high salivary P.gingivalis level seemed to be associated with a greater proinflammatory response in peri-implant mucositis, unlike in periodontally susceptible subjects. Host-susceptibility factors seem to modulate the biomarker/risk indicator value of salivary periodontopathogens. Salivary periodontopathogen and PISF IL-1β tests together may be useful for risk assessment in clinical implant dentistry.