*3.3.2 Metalloproteinases*

*Periodontal Disease - Diagnostic and Adjunctive Non-surgical Considerations*

Alkaline phosphatase has been evaluated in saliva as a possible biomarker for the detection of periodontitis. Dabra and Singh [16] first study 20 healthy subjects with gingivitis, and 20 with chronic periodontitis were included. This investigation showed a statistically significant increase in alkaline phosphatase activities in the saliva of patients with periodontal disease compared to the control group. A recent study of Patel et al. [69] included 150 healthy subjects, 50 patients with chronic generalized gingivitis, and 50 with periodontitis. In this study it was shown that alkaline phosphatase can be considered for the diagnosis of diseased and healthy periodontal tissues; since as the severity of periodontal disease increases, it also

The pH of the saliva has been evaluated, and it has been found that there is a significant change in the pH depending on the severity of the periodontal condition, so the pH can be useful as a rapid diagnostic biomarker in the consultation. The study suggests that the pH becomes alkaline when patients have chronic gingivitis, but it

A 2015 study found that the concentrations of ICTP were higher in the group with periodontitis and lower in the group with healthy patients; this study suggests that the level of ICTP in saliva increases as the patient presents with gingivitis and periodontitis, since the periodontitis samples had the maximum concentration of salivary ICTP. The authors suggest that more studies with a larger sample size be conducted to establish a correlation between the concentrations of ICTP and the

In the oral cavity, we find three fluids: the gingival crevicular fluid, the serum, and the total saliva. The gingival crevicular fluid is an exudate, and at present the quantification of its constituents is a current method to identify specific biomarkers

The gingival crevicular fluid is an exudate secreted by the gums that can be found in the crevices located at the point where the gumline meets the teeth. The concentrations of this fluid are usually low but may increase when an inflammatory

*3.3.1 Proteins (cytokines) involved in the inflammatory process of periodontitis*

It is considered that due to the noninvasive and simple nature of its collection, the analysis crevicular fluid can be beneficial in determining the periodontal status [75].

Regarding the cytokines that have been evaluated, we can say that they are very similar to those that were evaluated in the saliva; besides that the results are also similar since it has been found that IL-β is the most important cytokine since diverse studies confirm high levels in periodontal disease compared to healthy [48, 76, 77]. In the same way it happens with IL-2 and IL-6, where several studies conclude that both interleukins are important as biomarkers to identify patients with peri-

*3.2.5 Alkaline phosphatase*

increases alkaline phosphatase levels.

*3.2.7 Telopeptide (ICTP)*

individual clinical parameters [72].

with a reasonable sensitivity [73].

process occurs in the oral cavity [74].

odontal disease [48, 76, 78].

becomes acidic when there is periodontitis [71].

**3.3 Biomarkers determined in crevicular fluid**

*3.2.6 pH*

**26**

With respect to metalloproteinases, studies of biomarkers in crevicular fluid have shown that MMP-7 could be useful as a potential new biomarker for periodontitis [79]. Similar to that determined in saliva, MMP-8 is increased in patients with periodontitis and provides a good sensitive measure to establish differences between patients and healthy individuals [77]. It is also useful as a complementary tool in the periodontal diagnosis [67]. Another metalloproteinase that has proved useful is MMP-9. This metalloproteinase correlates with clinical measures and results in good sensitivity to predict the progression of periodontal disease [77].
