Effect of ultrasonic tip designs on intraradicular post removal.
OBJECTIVE
To evaluate the effect of different ultrasonic tip designs on intraradicular post removal.


METHODS
The crowns of forty human canine teeth were removed, and after biomechanical preparation and filling, the roots were embedded in acrylic resin blocks. The post spaces were made, and root canal molding was performed with self-cured acrylic resin. After casting (Cu-Al), the posts were cemented with zinc phosphate cement. The specimens were randomly separated into 4 groups (n = 10), as follows: G1 - no ultrasonic vibration (control); G2 - ultrasonic vibration using an elongated cylindrical-shaped and active rounded tip; G3 - ultrasonic vibration with a flattened convex and linear active tip; G4 - ultrasonic vibration with active semicircular tapered tip. Ultrasonic vibration was applied for 15 seconds on each post surface and tensile test was performed in a Universal Testing Machine (Instron 4444 - 1 mm/min).


RESULTS
G4 presented the highest mean values, however, with no statistically significant difference in comparison to G3 (P > 0.05). G2 presented the lowest mean values with statistically significant difference to G3 and G4 (P < 0.05).


CONCLUSIONS
Ultrasonic vibration with elongated cylindrical-shaped and active rounded tip was most effective in reducing force required for intraradicular post removal.
Department of Endodontics, School of Dentistry, Federal University of Amazonas, Manaus, Amazonas, Brazil.
Anny Carine Barros
AC
Aguiar
Department of Endodontics, School of Dentistry, Federal University of Amazonas, Manaus, Amazonas, Brazil.
Daniely Amorim
DA
de Meireles
Department of Endodontics, School of Dentistry, State University of Amazonas, Manaus, Amazonas, Brazil.
André Augusto Franco
AA
Marques
Department of Endodontics, School of Dentistry, Federal University of Amazonas, Manaus, Amazonas, Brazil.
Emílio Carlos
EC
Sponchiado Júnior
Department of Endodontics, School of Dentistry, Federal University of Amazonas, Manaus, Amazonas, Brazil.
Angela Delfina Bitencourt
AD
Garrido
Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
Lucas da Fonseca Roberti
Lda F
Garcia
Post removal; Tip design; Ultrasonic device