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 7 finding(s) in the abstract below. Please extract them. Output only the JSON array with these 7 findings. Do not include any additional text.

Abstract:
ABSTRACT.BACKGROUND:  This study aimed to compare glide path preparation of different pathfinding systems and their effects on the apical transportation of ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland) in mesial root canals of extracted human mandibular molars, using digital subtraction radiography.

ABSTRACT. MATERIAL AND METHODS :  The mesial canals of 40 mandibular first molars (with curvature angles between 25° and 35°) were selected for this study. The specimens were divided randomly into 4 groups with 10 canals each. Glide paths were created in group 1 with #10, #15 and #20 K-type (Dentsply Maillefer, Ballaigues, Switzerland) stainless steel manual files; in group 2 with Path-File (Dentsply Maillefer) #1, #2, and #3 and in group 3 with #16 ProGlider (Dentsply Maillefer) rotary instruments; in group 4 no glide paths were created. All canals were instrumented up to ProTaper Next X2 to the working length. A double digital radiograph technique was used, pre and post-instrumentation, to assess whether apical transportation and/or aberration in root canal morphology occurred. Instrument failures were also recorded. The data were analyzed statistically using ANOVA and Tukey tests (p<0.05).

ABSTRACT. RESULTS :  No significant differences were found among groups regarding apical transportation (p>0.05). Two ProTaper Next instruments failed in-group 4.

ABSTRACT. CONCLUSIONS :  Within the parameters of this study, there was no difference between the performance of path-finding files and ProTaper Next system maintained root canal curvature well and was safe to use either with path-finding files or alone. <p> 
 Key words:Glide path, PathFile, ProGlider, ProTaper Next, transportation.

Findings:
[["previously prepared with path-finding files", "not-prepared", "ProTaper Next system maintained root canal curvature", "no significant difference", "ProTaper Next system maintained root canal curvature well and was safe to use either with path-finding files or alone."], ["previously prepared with path-finding files", "not-prepared", "apical transportation values", "no significant difference", "No significant differences were found among groups regarding apical transportation (p\u003e0.05)."], ["group 1 with #10, #15 and #20 K-type (Dentsply Maillefer, Ballaigues, Switzerland) stainless steel manual files", "group 2 with Path-File (Dentsply Maillefer) #1, #2, and #3", "performance of path-finding files", "no significant difference", "there was no difference between the performance of path-finding files"], ["group 2 with Path-File (Dentsply Maillefer) #1, #2, and #3", "group 3 with #16 ProGlider (Dentsply Maillefer) rotary instruments", "performance of path-finding files", "no significant difference", "Within the parameters of this study, there was no difference between the performance of path-finding files and ProTaper Next system maintained root canal curvature well and was safe to use either with path-finding files or alone."], ["previously prepared with path-finding files", "not-prepared", "ProTaper Next system safety", "no significant difference", "Within the parameters of this study, there was no difference between the performance of path-finding files and ProTaper Next system maintained root canal curvature well and was safe to use either with path-finding files or alone."], ["group 1 with #10, #15 and #20 K-type (Dentsply Maillefer, Ballaigues, Switzerland) stainless steel manual files", "group 3 with #16 ProGlider (Dentsply Maillefer) rotary instruments", "performance of path-finding files", "no significant difference", "Within the parameters of this study, there was no difference between the performance of path-finding files and ProTaper Next system maintained root canal curvature well and was safe to use either with path-finding files or alone."], ["group 1 with #10, #15 and #20 K-type (Dentsply Maillefer, Ballaigues, Switzerland) stainless steel manual files", "group 3 with #16 ProGlider (Dentsply Maillefer) rotary instruments", "performance of path-finding files", "no significant difference", "No significant differences were found among groups regarding apical transportation (p\u003e0.05)."]]