You will be shown the abstract of a medical clinical trial report. Your task is to extract all the findings from this report into a JSON array. Each finding should contain the following five elements:

- Intervention: The medical intervention being tested. This should be a text span copied from the input passage.
- Comparator: The baseline against which the intervention is being evaluated. This should be a text span copied from the input passage. If no comparator is reported, set to `null`.
- Outcome: The medical outcome whose effect is being measured. This should be a text span copied from the input passage.
- Effect: The effect of the intervention on the outcome, relative to the comparator. The effect should be one of the following three values: ("significantly increased", "significantly decreased", "no significant difference").
- Evidence: The evidence for the effect. This should be a text span copied from the input passage.

Please format your output as a JSON array. Each entry in the output should be an array containing the 5 elements listed above, in the following order: [<intervention>, <comparator>, <outcome>, <effect>, <evidence>].

For example, an output with two findings might read:
```
[["aspirin", "placebo", "headache severity", "significantly decreased", "Mean headache severity was significantly decreased in the aspirin group compared to the placebo group (p < 0.05)."], ["aspirin", "placebo", "weight loss", "no significant difference", "We did not observe any difference in weight loss between the group given aspirin relative to the control group"]]
```

There are 6 finding(s) in the abstract below. Please extract them. Output only the JSON array with these 6 findings. Do not include any additional text.

Abstract:
ABSTRACT.OBJECTIVES:: The purpose of this study was to evaluate the effect of salivary pH on the shear bond strength (SBS) of orthodontic brackets to tooth surface.

ABSTRACT.MATERIALS AND METHODS:: Eighty intact premolars were randomly divided into four groups of 20. After bonding a bracket on each tooth, the groups one to four were stored in artificial saliva at a pH of 3.8, 4.8, 5.8, and 6.8, respectively for two months. The artificial saliva solutions were refreshed weekly. Each tooth was then embedded in an acrylic block so that the crown was exposed and its buccal surface was parallel to the direction of the force during SBS testing. All brackets were debonded using Dartec universal testing machine, and the mean values of SBS in different groups were compared using one-way analysis of variance (ANOVA).

ABSTRACT.RESULTS:: The mean SBS value in group one (pH 3.8) was significantly lower than that in other groups (P<0.05). The differences between other groups were not significant (P>0.05).

ABSTRACT.CONCLUSION:: Decreased salivary pH due to poor oral hygiene and/or frequent consumption of acidic beverages may be responsible for orthodontic bracket bond failure.

Findings:
[["pH 3.8 saliva ", "pH 6.8 saliva", "Shear bond strength", "significantly decreased", "The mean SBS value in group one (pH 3.8) was significantly lower than that in other groups (P\u003c0.05). The differences between other groups were not significant (P\u003e0.05)."], ["pH 6.8 saliva", "pH 5.8 saliva", "Shear bond strength", "no significant difference", "The mean SBS value in group one (pH 3.8) was significantly lower than that in other groups (P\u003c0.05). The differences between other groups were not significant (P\u003e0.05)."], ["pH 3.8 saliva ", "pH 5.8 saliva", "Shear bond strength", "significantly decreased", "The mean SBS value in group one (pH 3.8) was significantly lower than that in other groups (P\u003c0.05)."], ["pH 6.8 saliva", "pH 4.8 saliva", "Shear bond strength", "no significant difference", "The mean SBS value in group one (pH 3.8) was significantly lower than that in other groups (P\u003c0.05). The differences between other groups were not significant (P\u003e0.05)."], ["pH 3.8 saliva ", "pH 4.8 saliva", "Shear bond strength", "significantly decreased", "The mean SBS value in group one (pH 3.8) was significantly lower than that in other groups (P\u003c0.05)."], ["pH 5.8 saliva", "pH 4.8 saliva", "Shear bond strength", "no significant difference", "The mean SBS value in group one (pH 3.8) was significantly lower than that in other groups (P\u003c0.05). The differences between other groups were not significant (P\u003e0.05)."]]