Root Camp Lecture 5 - Working Length Determination - Instrumentation Flashcards
(22 cards)
Refers to the mechanical and chemical procedures performed inside the root canal to achieve specific objectives
Instrumentation
Primary objective is to thoroughly clean and shape the canal system, which is essential for removing debris and preparing the canal for 3D obturation
Instrumentation
What are the 4 objectives of instrumentation?
- Remove infected soft + hard tissue
- Give disinfecting irrigants access to apical canal space
- Create space to facilitate delivery of medicaments and obturation
- Retain integrity of radicular structures
Which stage of instrumentation?
Canal exploration w/ small hand files to gauge size, shape, and configuration of canals
Irrigation w/ antimicrobials (bleach)
Coronal preflaring to facilitate placing subsequent files to WL
Maintaining antimicrobial efficiency by frequent and copious irrigation
Negotiation to apical foramen, establishing patency and WL
Achieving a predictable glide path to FL
Stage 1
Which stage of instrumentation?
Shaping to FL w/ rotary instruments while using frequent irrigation turnover (hand instrumentation should be done passively)
Determining apical constriction size and correction of final canal size accordingly
Stage 2
What are the 6 steps of instrumentation?
Exploration (scouting)
Coronal flaring
Determine WL
Apical patency
Glide path
Instrumentation
Initial step in accessing entire length of the canal
Exploration (scouting)
Precedes establishment of apical patency and refers to initial canal exploration w/ passive, small flexible files attempting to progress toward the apex up to TWL
Exploration (scouting)
Determine the #, direction of curvature, and size of canals, and assess whether access to the apical third is possible
Exploration (scouting)
Determined by subtracting 2 mm from the length of the tooth measured on the initial X-Ray
TWL (tentative working length)
Which step of instrumentation?
Start w/ irrigation always (3.5% NaOCl)
Pre-curved small files
Calibrate the files in TWL
Negotiate canal openings
Move around ledges and calcifications
Avoid sharp kinks
Exploration
Goal of this step is to establish FL (full length) of the tooth to determine WL (working length) for completing instrumentation and filing
WL determination
What are the 2 ways to determine WL?
Radiographic technique
Electronic apex locator
Which step of instrumentation?
Use cusp next to canal being treated
Make sure stop is on file correctly and not tilted
Stoppers must be new and tight on files
Flatten cusps to give accurate reference point
WL determination
Determined by subtracting 2 mm from the length of the tooth measured on the initial X-Ray
WL (working length)
Aims to keep apical foramen unobstructed during canal shaping
Apical patency
Maintained by a smaller number instrument (#10 or #15), which is used to negotiate the canal to the major foramen of the root canal (FL), btwn each instrument used during instrumentation
Apical patency
Physical phenomenon, trapping of gases derived from hydrolysis of organic tissues
Apical vapor lock
Refers to a smooth, reproducible, minimally invasive pathway created from the coronal canal orifice to the apical foramen before beginning the use of larger shaping instruments
Glide path
Created when a small flexible file can smoothly and consistently move from the entrance of the canal to the apex
Glide path
Minimum size for this file should be similar to a super loose size #10 file or a loose size #15 file
Glide path
