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The effect of a manual instrumentation technique on five types of premolar root canal geometry assessed by microcomputed tomography and three-dimensional reconstruction.

Li KZ, Gao Y, Zhang R, Hu T, Guo B - BMC Med Imaging (2011)

Bottom Line: The selection of instrumentation techniques for variants in internal anatomy of teeth has significant effects on the shaping ability and cleaning effectiveness.Instrumentation characteristics were measured quantitatively in 3-D using a customized application framework based on MeVisLab.Further study is needed to demonstrate the differences made by including variations in the internal anatomy of teeth into the study protocol of clinical RCT for identifying the best preparation technique.

View Article: PubMed Central - HTML - PubMed

Affiliation: State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, Chengdu, P.R. China.

ABSTRACT

Background: Together with diagnosis and treatment planning, a good knowledge of the root canal system and its frequent variations is a necessity for successful root canal therapy. The selection of instrumentation techniques for variants in internal anatomy of teeth has significant effects on the shaping ability and cleaning effectiveness. The aim of this study was to reveal the differences made by including variations in the internal anatomy of premolars into the study protocol for investigation of a single instrumentation technique (hand ProTaper instruments) assessed by microcomputed tomography and three-dimensional reconstruction.

Methods: Five single-root premolars, whose root canal systems were classified into one of five types, were scanned with micro-CT before and after preparation with a hand ProTaper instrument. Instrumentation characteristics were measured quantitatively in 3-D using a customized application framework based on MeVisLab. Numeric values were obtained for canal surface area, volume, volume changes, percentage of untouched surface, dentin wall thickness, and the thickness of dentin removed. Preparation errors were also evaluated using a color-coded reconstruction.

Results: Canal volumes and surface areas were increased after instrumentation. Prepared canals of all five types were straightened, with transportation toward the inner aspects of S-shaped or multiple curves. However, a ledge was formed at the apical third curve of the type II canal system and a wide range in the percentage of unchanged canal surfaces (27.4-83.0%) was recorded. The dentin walls were more than 0.3 mm thick except in a 1 mm zone from the apical surface and the hazardous area of the type II canal system after preparation with an F3 instrument.

Conclusions: The 3-D color-coded images showed different morphological changes in the five types of root canal systems shaped with the same hand instrumentation technique. Premolars are among the most complex teeth for root canal treatment and instrumentation techniques for the root canal systems of premolars should be selected individually depending on the 3-D canal configuration of each tooth. Further study is needed to demonstrate the differences made by including variations in the internal anatomy of teeth into the study protocol of clinical RCT for identifying the best preparation technique.

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Color-coded distance images showing the changes in canal shape during instrumentation. The distance also indicates the amount of dentin removed. The images in the top and bottom row are viewed from buccolingual and mesiodistal directions, respectively. Letters indicate the same teeth as in Figure 1.
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Figure 4: Color-coded distance images showing the changes in canal shape during instrumentation. The distance also indicates the amount of dentin removed. The images in the top and bottom row are viewed from buccolingual and mesiodistal directions, respectively. Letters indicate the same teeth as in Figure 1.

Mentions: In the mesiodistal direction, all main canals were straightened after preparation with an F3 instrument and the straightening tended to occur toward the inner aspects of the curved parts of the root canal of teeth B, C, D and E (Figure 3). However, when viewed from the buccolingual direction, there was a transportation toward the outer aspects of the root canal and ledge formation at the apical third curve of Tooth B. Corresponding with the trend in canal transportation, more dentin was removed at the inner aspects of the curved parts and the outer aspect at the apical third curve of Tooth B (Figure 4).


The effect of a manual instrumentation technique on five types of premolar root canal geometry assessed by microcomputed tomography and three-dimensional reconstruction.

Li KZ, Gao Y, Zhang R, Hu T, Guo B - BMC Med Imaging (2011)

Color-coded distance images showing the changes in canal shape during instrumentation. The distance also indicates the amount of dentin removed. The images in the top and bottom row are viewed from buccolingual and mesiodistal directions, respectively. Letters indicate the same teeth as in Figure 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3142503&req=5

Figure 4: Color-coded distance images showing the changes in canal shape during instrumentation. The distance also indicates the amount of dentin removed. The images in the top and bottom row are viewed from buccolingual and mesiodistal directions, respectively. Letters indicate the same teeth as in Figure 1.
Mentions: In the mesiodistal direction, all main canals were straightened after preparation with an F3 instrument and the straightening tended to occur toward the inner aspects of the curved parts of the root canal of teeth B, C, D and E (Figure 3). However, when viewed from the buccolingual direction, there was a transportation toward the outer aspects of the root canal and ledge formation at the apical third curve of Tooth B. Corresponding with the trend in canal transportation, more dentin was removed at the inner aspects of the curved parts and the outer aspect at the apical third curve of Tooth B (Figure 4).

Bottom Line: The selection of instrumentation techniques for variants in internal anatomy of teeth has significant effects on the shaping ability and cleaning effectiveness.Instrumentation characteristics were measured quantitatively in 3-D using a customized application framework based on MeVisLab.Further study is needed to demonstrate the differences made by including variations in the internal anatomy of teeth into the study protocol of clinical RCT for identifying the best preparation technique.

View Article: PubMed Central - HTML - PubMed

Affiliation: State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, Chengdu, P.R. China.

ABSTRACT

Background: Together with diagnosis and treatment planning, a good knowledge of the root canal system and its frequent variations is a necessity for successful root canal therapy. The selection of instrumentation techniques for variants in internal anatomy of teeth has significant effects on the shaping ability and cleaning effectiveness. The aim of this study was to reveal the differences made by including variations in the internal anatomy of premolars into the study protocol for investigation of a single instrumentation technique (hand ProTaper instruments) assessed by microcomputed tomography and three-dimensional reconstruction.

Methods: Five single-root premolars, whose root canal systems were classified into one of five types, were scanned with micro-CT before and after preparation with a hand ProTaper instrument. Instrumentation characteristics were measured quantitatively in 3-D using a customized application framework based on MeVisLab. Numeric values were obtained for canal surface area, volume, volume changes, percentage of untouched surface, dentin wall thickness, and the thickness of dentin removed. Preparation errors were also evaluated using a color-coded reconstruction.

Results: Canal volumes and surface areas were increased after instrumentation. Prepared canals of all five types were straightened, with transportation toward the inner aspects of S-shaped or multiple curves. However, a ledge was formed at the apical third curve of the type II canal system and a wide range in the percentage of unchanged canal surfaces (27.4-83.0%) was recorded. The dentin walls were more than 0.3 mm thick except in a 1 mm zone from the apical surface and the hazardous area of the type II canal system after preparation with an F3 instrument.

Conclusions: The 3-D color-coded images showed different morphological changes in the five types of root canal systems shaped with the same hand instrumentation technique. Premolars are among the most complex teeth for root canal treatment and instrumentation techniques for the root canal systems of premolars should be selected individually depending on the 3-D canal configuration of each tooth. Further study is needed to demonstrate the differences made by including variations in the internal anatomy of teeth into the study protocol of clinical RCT for identifying the best preparation technique.

Show MeSH