An in vitro evaluation of apicoectomies and retropreparations using different methods.
OBJECTIVE
The aim of this study was to evaluate: 1) the apical root surface, gutta-percha interface, and preparation time of root-end resections made with burs, ultrasound, or laser; and 2) the thickness of surrounding dentin after laser or ultrasonic root-end cavity preparation.


METHODS
1) Thirty root-filled teeth were resected as follows: Zekrya bur in group I, Chemical Vapor Deposition (CVD) ultrasonic tip (9.5107-8) in group II, and ErCr:YSGG (Waterlase) in group III. The preparation time was recorded. Replicas of the resected root-ends were examined under a scanning electron microscope (SEM). 2) Thirty root-filled teeth were submitted to apicectomies and root-end cavities were prepared by using: CVD (6.1107-6) ultrasonic retrotips (group IV), EMS (DT-060) ultrasonic retrotips (group V), and ErCr:YSGG laser tips (group VI). Replicas of the root apices were examined under a SEM.


RESULTS
There were no fissures or fractures on root-end surfaces. The bur produced the smoothest surface (P < .05). Group I had the lowest preparation time (P < .05). The best adaptation between the filling and the root canals walls was observed in group III, but it was not significantly different from group II (P < .05). No resected root-ends had cracks after preparation. Group VI showed the least minimum dentin thickness (P < .05).


CONCLUSIONS
The 3 methods evaluated did not cause any injury to the root-end surface, but they harmed the apical adaptation. Laser tips removed more dentin than ultrasonic retrotips and should be used with care to avoid overpreparation.
Camargo Villela Berbert
Fábio Luiz
FL
Department of Restorative Dentistry, Araraquara School of Dentistry, São Paulo State University, Araraquara, Brazil.
de Faria-Júnior
Norberto Batista
NB
Tanomaru-Filho
Mário
M
Guerreiro-Tanomaru
Juliane Maria
JM
Bonetti-Filho
Idomeo
I
Leonardo
Renato de Toledo
Rde T
Marcantonio
Rosemary Adriana Chierici
RA
D000704:Analysis of Variance; D001047:Apicoectomy / Q000295:instrumentation / Q000379:methods; D003762:Dental Instruments; D018772:Dental Marginal Adaptation; D003804:Dentin / Q000033:anatomy & histology; D006171:Gutta-Percha; D006801:Humans; D053844:Lasers, Solid-State; D012184:Retrograde Obturation / Q000379:methods; D012387:Root Canal Filling Materials; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D018709:Statistics, Nonparametric; D014465:Ultrasonics
D012387:Root Canal Filling Materials; D006171:Gutta-Percha