.The hypotheses behind this study were:
\- The aMMP-8 test discriminates between individuals with and without untreated generalized chronic periodontitis
Thus, sensitivity and specificity of a chair-side test for activated matrix metalloproteinase-8 to distinguish between individuals with and without untreated chronic periodontitis as well as between patients with generalized moderate and generalized severe ChP was evaluated.
Patients
A commercially available chair side test to detect increased levels of activated matrix metalloproteinase-8 was used at Dr. Matthias Mayer's dental office (Arndtstr. 14, 60325 Frankfurt am Main) in periodontally healthy individuals and patients with untreated generalized moderate chronic periodontitis (mChP) and generalized severe chronic Periodontitis (sChP).
The companies had provided 70 tests for use. During use the idea arose to retrospectively correlate test results and clinical diagnoses. Thus, a study protocol was submitted to the ethics committee of the Medical Faculty of the Johann Wolfgang Goethe-University Frankfurt/Main. All patients that were examined prior to the vote of the ethics committee were evaluated retrospectively. All following patients were recruited prospectively.
All patients were asked about current smoking (yes/no) and education level (basic school, high school, university). The study complied with the rules of the Declaration of Helsinki and was approved by the Institutional Review Board for Human Studies of the Medical Faculty of the Goethe-University Frankfurt/Main (Application# 144/13).
Chair side test
For all periodontitis patients the activated matrix metalloproteinase-8 test was performed at least 24 hours after clinical examination. For periodontally healthy controls the test was done within a week after clinical examination. First of all patients rinsed with tap water for 30 seconds. Then they spat out the water and waited for 1 min. Now patients rinsed with 5ml of purified water for 30 seconds and spat this sample back into the test cup. Approximately 2 ml of the sampled saliva was now taken up with a syringe. After a filter was put onto the syringe 3 drops of the saliva were pressed through the filter into the ELISA kit. After 5 to 10 min the result was read from the test kit. If both the control and test stripes were visible the respective test was positive (i.e. ≥ 25 ng activated matrix metalloproteinase-8 per ml). All test results were photographed with 2fold magnification.
Statistical analysis
The patient was looked upon as statistical unit. The sensitivity and specificity of the aMMP-8 test was defined as the main outcome variables. All other parameters were control variables.
For all individuals, cigarette pack years were calculated. Group frequencies were expressed for sex, current smoking, education, and activated matrix metalloproteinase-8 (positive/negative). Group means and standard deviations were calculated for age and bleeding on probing. Further, for each individual the following variables were calculated to describe the periodontal status.
Comparisons between groups for dichotomous parameters were made by χ² or Fisher's exact test and for all other parameters by Kruskal-Wallis and Mann-Whitney-U test.
Using backward stepwise logistic regression analysis, factors should be identified that were associated with positive activated matrix metalloproteinase-8 tests.
