Would nitric oxide be an effective marker for earlier stages of peri-implant disease? An analysis in human peri-implant sulcular fluid.

Nitric oxide has an important effect on host immune response. However, little has been studied in relation to its potential as a possible diagnostic tool in peri-implant disease. The present study analyzed nitrite levels in the peri-implant sulcular fluid (PISF) of implants with mucositis and the correlation of these nitrite levels with clinical parameters using a simplified fluid collection methodology. Twenty-five partially edentulous patients showing peri-implant mucositis were evaluated, and the peri-implant status was determined based on current clinical parameters: probing depth (PD) and bleeding on probing (BOP). The sulcular fluid (SF) around teeth (control) and implants were collected, and the nitrite levels were evaluated using the Griess method. The mean probing depth (mm) was significantly higher (P < .0001) in implants (2.852 ± 0.6484) than in control teeth (1.585 ± 0.3636). The mean total nitrite level (μM) was statistically higher (P = .0069) in implants with mucositis (14.34 ± 11.83) than in control teeth (9.316 ± 5.534). No correlation was observed between the total nitrite levels and the PD mean in the control group (P = .2558, r = -0.2361) or in the implant group (P = .1160, r = -0.3224), as well as the number of faces showing bleeding on probing (P = .8747, r = 0.0332). These results demonstrated that the nitrite levels were higher in inflamed areas. According to the methodology applied and results obtained, the higher nitrite levels in inflamed areas suggest that, in the future, nitrite could be used as a marker of peri-implant mucositis associated with clinical data to monitor the cure or evolution of the disease.