Combine Non Taper with Taper for Absolute Success

Tapered instrumentation technique- Suboptimal cleaning even of Pulp tissue (J Endod 2010;36:1897–1900)
Fifty-four recently extracted vital lower incisors were instrumented with either
a full range of ProTaper Universal instruments in rotary motion (group 1) or with the single-file F2 ProTaper technique in reciprocating motion (group 2). Teeth were previously classified as round or oval-shaped by means of bidirectional radiographs, resulting in 24 round canals, 24 oval canals, and 12 controls.

(E) Photomicrograph of oval-shaped canal instrumented by F2 ProTaper technique. Arrows indicate presence of significant amount of remaining pulp tissue in the unprepared lingual and buccal extensions. (F) Photomicrograph of oval-shaped canal instrumented by full ProTaper Universal sequence. Arrow indicates presence of significant amount of remaining pulp tissue

The percentage of residual pulp tissue (PRPT) was calculated with the aid of image analysis software. Univariate analysis of variance was used to verify the variables influencing PRPT.
Results: Group 1 displayed considerably less PRPT in oval canals than group 2
(P < .05), whereas in round canals no significant difference was found between the 2 techniques (P > .05).
Conclusions: The single-file F2 ProTaper technique displayed similar PRPT to the full range of ProTaper instruments in round canals. However, the debridement quality of the single-file F2 ProTaper technique was suboptimal in oval canals.