Post Space Depth Rule Calculator
Caller-established retained apical length subtracted from independently measured available root length, compared to actual post-space depth. Not universal two-thirds rule, adequate seal, strength or permission to prepare a post.
Description
Post-space geometry must account for independently required retained apical length.
Post-space geometry must account for independently required retained apical length.1
A geometric ceiling compares lengths without selecting the clinically appropriate preparation. Use this tool to calculate the stated observation or conditional model from supplied measurements.
When to use Post Space Depth Rule Calculator
Use this tool to calculate the stated observation or conditional model from supplied measurements. Establish the qualified examination or measurement context, matching instrument/protocol edition, site order and units.
How to use Post Space Depth Rule Calculator and understand its results
- Establish the qualified examination or measurement context, matching instrument/protocol edition, site order and units.
- Enter independentlyMeasuredAvailableRootLengthMm, callerClinicianEstablishedRequiredApicalRetainedLengthMm, actualMeasuredPostSpaceDepthMm, using the field meanings and rules below, then run the tool.
- Read result.conditionalCallerGeometricPostSpaceCeilingMm, result.signedDepthMarginMm. Interpret each field using the units, signs and evidence rules below.
- If input validation fails, correct the reported field and run again. Before applying a successful result, check the stated reference scope, units, assumptions and any retained unknown evidence.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| independentlyMeasuredAvailableRootLengthMm | Independently measured available root length mm | number | Required |
| callerClinicianEstablishedRequiredApicalRetainedLengthMm | Caller clinician established required apical retained length mm | number | Required |
| actualMeasuredPostSpaceDepthMm | Actual measured post space depth mm | number | Required |
Require nonnegative available root length, independently required retained apical length and measured post-space depth in millimeters. Require retained≤available; subtract retained from available for a ceiling and measured depth from that ceiling for a signed margin. A negative margin is returned rather than rejected; no retention default or treatment recommendation is chosen.
geometricCeilingMm=availableRootMm−callerRequiredRetainedMm; signedMarginMm=ceilingMm−actualPostDepthMm Apply the field units and exact ordering, boundary and evidence rules above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Structured result containing the calculation or selected reference fields below | object |
| result.conditionalCallerGeometricPostSpaceCeilingMm | Conditional Caller Geometric Post Space Ceiling Mm; use the units, sign convention and calculation stated above | number |
| result.signedDepthMarginMm | Signed Depth Margin Mm; use the units, sign convention and calculation stated above | number |
{
"input": {
"independentlyMeasuredAvailableRootLengthMm": 15,
"callerClinicianEstablishedRequiredApicalRetainedLengthMm": 5,
"actualMeasuredPostSpaceDepthMm": 8
},
"output": {
"result": {
"conditionalCallerGeometricPostSpaceCeilingMm": 10,
"signedDepthMarginMm": 2
}
}
}Limitations and assumptions
A geometric ceiling compares lengths without selecting the clinically appropriate preparation. Results depend on the independently established measurement basis and the exact model assumptions above.
Every listed input requires an explicit value. Unexpected fields, incorrect value types, nonfinite numbers and sparse numeric arrays fail validation; tool-specific bounds and alignment rules apply as described above. Extremely large inputs or outputs can also be rejected. An input error is distinct from a successful calculation that reports a false comparison or retains unknown evidence.
Alternative or Complementary methods
Use Working Length Radiograph Adjustment Calculator to examine a related aspect: Radiographic lengths may be scaled using a file of independently known inserted length.
Use Endo File Length From Tooth Calculator where its separate inputs and scope apply: A working reference length can be expressed as a tooth reference minus a selected apical offset.
References
-
Post Space Depth Rule Calculator — tool.io
Similar or alternative tools
- Working Length Radiograph Adjustment Calculator
Radiographic lengths may be scaled using a file of independently known inserted length.
- Endo File Length From Tooth Calculator
A working reference length can be expressed as a tooth reference minus a selected apical offset.