Article Options
Categories


Search


Advanced Search



This service is provided on D[e]nt Publishing standard Terms and Conditions. Please read our Privacy Policy. To enquire about a licence to reproduce material from endodonticsjournal.com and/or JofER, click here.
This website is published by D[e]nt Publishing Ltd, Phoenix AZ, US.
D[e]nt Publishing is part of the specialist publishing group Oral Science & Business Media Inc.

Creative Commons License


Recent Articles RSS:
Subscribe to recent articles RSS
or Subscribe to Email.

Blog RSS:
Subscribe to blog RSS
or Subscribe to Email.


Azerbaycan Saytlari

 »  Home  »  Endodontic Articles 10  »  Smooth flexible versus active tapered shaft design using NiTi rotary instruments
Smooth flexible versus active tapered shaft design using NiTi rotary instruments
Results.



Experimental groups.
Initial analysis of canal curvature and PRE-volume indicated no significant differences between the two groups (Table 1) (t-test).

Qualitative analysis.
Volume rendering revealed detailed images of general and local canal shape before (PRE) and after (POST) instrumentation (Fig.5). Visual inspection of the POST-volume images in 3608 rotation disclosed no aberrations.

Table 1. Morphometric data determined for uninstrumented mandibular mesial root canals (means +SD, n =10).

Morphometric data determined for uninstrumented mandibular mesial root canals

Figure 5. Representative 3D computer-generated images of the canal shape for the two instrumentation groups.

Representative 3D computer-generated images of the canal shape for the two instrumentation groups

Quantitative analysis.

Dentine removal.
Quantitative analysis revealed that instrumentation resulted in increase in total canal volume (mean _ SD) of 0.97 _0.39 mm3 for the ‘Smooth’ (LS) group, and 1.43 _0.85 mm3 for the ‘Active’ (GT) group. Differences between the two groups were not statistically significant (Wilcoxon test). However, the amount of horizontal region-dependent dentine removal indicated more significant (P < 0.05) dentine removal in the middle to apical third of the root for the ‘Active’ (GT) group when compared to the ‘Smooth’ (LS) group (Wilcoxon test) (Table 2).

Table 2. Dentine removal (means +SD) (mm3) related to instrument type and horizontal region.

Dentine removal (means +SD) (mm3) related to instrument type and horizontal region

Transportation, net transportation and centring ability.
The ability of the instrument to remain centred is more important than the volume of dentine lost. No significant differences were observed in amount of canal transportation between the two groups at all five levels studied. However, significant differences were observed in the direction of transportation (Tables 3 and 4). Both groups showed significantly (P < 0.0001) more transportation towards the furcation area (directions 3 and 4) at the most coronal level (level 5) (Table 3). For the ‘Smooth’ group (LS), this effect was also significant (P < 0.001) at the middle-coronal level (level 4). In addition, the ‘Active’ group (GT) showed significantly (P < 0.01) more transportation towards the outer aspect of the curve (directions 7 and 8) than towards the inner aspect (directions 4 and 5) at the apical level (level1).
Net transportation and centring ability showed comparable results for both groups (Table 4).At the most coronal level (level 5), the net transportation and centre displacement was more (P < 0.0001) towards the inner side (directions 3 and 4) than towards the outer side of the curvature (directions 7 and 8). At mid-curvature (level 3), more dentine was removed at the outer part of the curve (P < 0.01), resulting in a centre displacement towards the mesio-buccal or mesio-lingual direction (direction 8). More apical to this point (levels 1 and 2), the outer relocation (directions 1, 7 and 8) of the centre was even more generalized (P < 0.0001).