Shaping Ability of Reciprocating and Rotary Systems After Root Canal Retreatment: a CBCT Study.

The purpose of this in vitro study was to evaluate the shaping ability of reciprocating and continuous rotary systems after root canal retreatment. After preparation and root canal filling, mesial canals of 54 mandibular molars were distributed into 3 groups (n=18), according to the filling material removal and re-instrumentation protocols: WOG group - WaveOne Gold system; PTN group - ProTaper Next system; and PTU group - ProTaper Universal system. Cone-beam computed tomographic (CBCT) images acquisition of the mesial root canals was performed at different moments: (1) before instrumentation (unprepared root canals), (2) after preparation and filling, (3) after filling material removal and (4) re-instrumentation. The apical transportation (AT), centering ability (CA) and change in root canal diameter were assessed by CBCT analysis. The remaining filling material quantification was performed by radiographic examination. The statistical analyses were performed using the 3-way ANOVA, Tukey-Kramer, Kruskal-Wallis and Dunn multiple Comparison tests (p<0.05). The tested instruments did not show full CA (=1.0). PTN group had greater AT at the 5th mm in comparison with the WOG group (p<0.05). After re-instrumentation, WOG group had greater root canal diameter change at the 1st and 5th mm than PTN and PTU groups (p<0.05). There was no significant difference among groups when comparing the amount of remaining filling material after re-instrumentation (p>0.05). The tested systems provided minimal alteration in root canal morphology at the apical portion after root canal retreatment. However, WOG promoted greater change in root canal diameter.

Shaping Ability of Reciprocating and Rotary Systems After Root Canal Retreatment: a CBCT Study

Abstract The purpose of this in vitro study was to evaluate the shaping ability of reciprocating and continuous rotary systems after root canal retreatment. After preparation and root canal filling, mesial canals of 54 mandibular molars were distributed into 3 groups (n=18), according to the filling material removal and re-instrumentation protocols: WOG group - WaveOne Gold system; PTN group - ProTaper Next system; and PTU group - ProTaper Universal system. Cone-beam computed tomographic (CBCT) images acquisition of the mesial root canals was performed at different moments: (1) before instrumentation (unprepared root canals), (2) after preparation and filling, (3) after filling material removal and (4) re-instrumentation. The apical transportation (AT), centering ability (CA) and change in root canal diameter were assessed by CBCT analysis. The remaining filling material quantification was performed by radiographic examination. The statistical analyses were performed using the 3-way ANOVA, Tukey-Kramer, Kruskal-Wallis and Dunn multiple Comparison tests (p<0.05). The tested instruments did not show full CA (=1.0). PTN group had greater AT at the 5th mm in comparison with the WOG group (p<0.05). After re-instrumentation, WOG group had greater root canal diameter change at the 1st and 5th mm than PTN and PTU groups (p<0.05). There was no significant difference among groups when comparing the amount of remaining filling material after re-instrumentation (p>0.05). The tested systems provided minimal alteration in root canal morphology at the apical portion after root canal retreatment. However, WOG promoted greater change in root canal diameter.

Resumo O objetivo deste estudo in vitro foi avaliar a capacidade de modelagem de sistemas rotatórios e reciprocantes após o retratamento do canal radicular. Após o preparo e obturação do canal radicular, os canais mesiais de 54 molares inferiores foram distribuídos em 3 grupos, de acordo com os protocolos de remoção do material obturador e re-instrumentação: (n=18): grupo WOG - sistema WaveOne Gold; Grupo PTN - sistema ProTaper Next; e grupo PTU - sistema ProTaper Universal. A análise das imagens de tomografia computadorizada de feixe cônico foi realizada em diferentes momentos: (1) antes da instrumentação (canais radiculares não preparados), (2) após o preparo e obturação, (3) após a remoção do material obturador e (4) re-instrumentação. O transporte apical (TA), a capacidade de centralização (CC) e a mudança no diâmetro do canal radicular foram avaliados por análise tomográfica. A quantificação do restante do material obturador foi realizada por exame radiográfico. As análises estatísticas foram realizadas utilizando os testes de ANOVA de 3 fatores, Tukey-Kramer, Kruskal-Wallis e Comparações Múltiplas de Dunn (p<0,05). Os instrumentos não apresentaram CC perfeita (=1,0). PTN apresentou maior TA no 5º mm em comparação ao grupo WOG (p<0,05). Após a re-instrumentação, o grupo WOG apresentou maior aumento no diâmetro do canal radicular no 1° e 5° mm do que os grupos PTN e PTU. Não houve diferença significativa entre os grupos em relação à remoção do material obturador (p>0,05). Os sistemas testados proporcionaram alteração mínima na morfologia do canal radicular na porção apical após o retratamento do canal radicular. No entanto, WOG promoveu maior alteração no diâmetro do canal radicular.

Comparison of the effect of photobiomodulation therapy and Ibuprofen on postoperative pain after endodontic treatment: randomized, controlled, clinical study.

The aim of the study was to compare the effect of Ibuprofen and the application of photobiomodulation therapy protocol on the reduction of postoperative pain in endodontically treated teeth using a randomized clinical trial design. Seventy patients, diagnosed with symptomatic irreversible pulpitis, were selected. Treatment was performed by a single operator; a reciprocal system was used to prepare the canals; they were obturated using the Tagger's hybrid technique and coronally sealed with glass-ionomer cement. After treatment, patients were randomly divided into 2 groups. In the active control group, two Ibuprofen 600 mg tablets were administered within a 12-h interval. In the photobiomodulation therapy group, the irradiation was applied after treatment. The evaluation of postoperative pain was performed by another researcher blinded to the groups at 6, 12, 24, and 72 h intervals after treatment. To measure the outcome, two pain scales were used: numerical rate scale (NRS) and verbal rate scale (VRS). Data were analyzed using the chi-square, Mann-Whitney, and Wilcoxon paired tests. Outcome was superior with photobiomodulation therapy at 6 h (p < 0.001), 12 h (p = 0.005), and 24 h (p < 0.001) intervals compared with Ibuprofen. The results for the 72 h (p = 0.317) interval were similar, both in the VRS and NRS scales. It may be concluded that the use of photobiomodulation therapy was effective in reducing pain within the first 24 h when compared with the administration of Ibuprofen 600 mg.

Effect of passive ultrasonic agitation during final irrigation on cleaning capacity of hybrid instrumentation.

OBJECTIVES: To evaluate the effect of passive ultrasonic agitation on the cleaning capacity of a hybrid instrumentation technique. MATERIALS AND METHODS: Twenty mandibular incisors with mesiodistal-flattened root shape had their crowns sectioned at 1 mm from the cementoenamel junction. Instrumentation was initiated by catheterization with K-type files (Denstply Maillefer) #10, #15, and #20 at 3 mm from the working length. Cervical preparation was performed with Largo bur #1 (Dentsply Maillefer) followed by apical instrumentation with K-type files #15, #20 and #25, and finishing with ProTaper F2 file (Denstply Maillefer). All files were used up to the working length under irrigation with 1 mL of 2.5% sodium hypochlorite (Biodynâmica) at each instrument change. At the end of instrumentation, the roots were randomly separated into 2 groups (n = 10). All specimens received final irrigation with 1 mL of 2.5% sodium hypochlorite. The solution remained in the root canals in Group 1 for one minute; and ultrasonic agitation was performed in Group 2 for one minute using a straight tip inserted at 1 mm from working length. The specimens were processed histologically and the sections were analyzed under optic microscope (×64) to quantify debris present in the root canal. RESULTS: The samples submitted to ultrasonic agitation (Group 2) presented significant decrease in the amount of debris in comparison with those of Group 1 (p < 0.05). CONCLUSIONS: The hybrid instrumentation technique associated with passive ultrasonic agitation promoted greater debris removal in the apical third of the root canals.