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.

Effect of Occlusal Adjustment on Postoperative Pain after Root Canal Treatment: A Randomized Clinical Trial.

The aim of this prospective, randomized, clinical study was to analyze the influence of occlusal adjustment on the prevalence of postoperative pain after endodontic treatment. Seventy-eight patients, diagnosed with symptomatic irreversible pulpitis with indication for endodontic treatment, were selected to participate in the study. The participants were randomized and divided into two groups: in the occlusal adjustment group (OAG), endodontic treatment was performed with subsequent occlusal adjustment. In the control group (CG), endodontic treatment was performed without occlusal adjustment. Treatments were performed by the same operator. Pain occurrence and intensity were recorded on two scales: the verbal rating scale (VRS) and numerical rating scale (NRS). Pain assessment was carried out by a second examiner, blinded to the experiment, 6, 24 and 72 h after endodontic treatment. Data were analyzed using Mann-Whitney, chi-squared, and Fisher's exact tests. In the occlusal adjustment group, 71.1% reported postoperative pain and 67.5% reported pain in the control group. At the 6-hour assessment, 21 individuals reported pain in the occlusal adjustment group and 24 in the control group (p=0.672). At the 24-hour assessment, 18 and 19 individuals reported pain (p=0.991) and at the 72-hour assessment, 8 and 4 reported pain (p=0.219), respectively. Occlusal adjustment did not influence the prevalence of postoperative pain of endodontically treated teeth with symptomatic irreversible pulpitis.

Effect of occlusal adjustment on postoperative pain after root canal treatment: a randomized clinical trial

Abstract The aim of this prospective, randomized, clinical study was to analyze the influence of occlusal adjustment on the prevalence of postoperative pain after endodontic treatment. Seventy-eight patients, diagnosed with symptomatic irreversible pulpitis with indication for endodontic treatment, were selected to participate in the study. The participants were randomized and divided into two groups: in the occlusal adjustment group (OAG), endodontic treatment was performed with subsequent occlusal adjustment. In the control group (CG), endodontic treatment was performed without occlusal adjustment. Treatments were performed by the same operator. Pain occurrence and intensity were recorded on two scales: the verbal rating scale (VRS) and numerical rating scale (NRS). Pain assessment was carried out by a second examiner, blinded to the experiment, 6, 24 and 72 h after endodontic treatment. Data were analyzed using Mann-Whitney, chi-squared, and Fisher's exact tests. In the occlusal adjustment group, 71.1% reported postoperative pain and 67.5% reported pain in the control group. At the 6-hour assessment, 21 individuals reported pain in the occlusal adjustment group and 24 in the control group (p=0.672). At the 24-hour assessment, 18 and 19 individuals reported pain (p=0.991) and at the 72-hour assessment, 8 and 4 reported pain (p=0.219), respectively. Occlusal adjustment did not influence the prevalence of postoperative pain of endodontically treated teeth with symptomatic irreversible pulpitis.

Resumo O objetivo deste estudo prospectivo, randomizado e clínico foi analisar a influência do ajuste oclusal na prevalência de dor pós-operatória após o tratamento endodôntico. Setenta e oito pacientes, diagnosticados com pulpite irreversível sintomática com indicação de tratamento endodôntico, foram selecionados para participar do estudo. Os participantes foram randomizados e divididos em dois grupos: no grupo de ajuste oclusal (GAO), foi realizado tratamento endodôntico com posterior ajuste oclusal. No grupo controle (GC), o tratamento endodôntico foi realizado sem ajuste oclusal. Os tratamentos foram realizados pelo mesmo operador. A ocorrência e a intensidade da dor foram registradas em duas escalas: a escala de classificação verbal (VRS) e a escala de classificação numérica (NRS). A avaliação da dor foi realizada por um segundo examinador, cego para o experimento, 6, 24 e 72 horas após o tratamento endodôntico. Os dados foram analisados utilizando testes de Mann-Whitney, qui-quadrado e exato de Fisher. No grupo de ajuste oclusal, 71,1% relataram dor pós-operatória e 67,5% relataram dor no grupo controle. Na avaliação de 6 horas, 21 indivíduos relataram dor no grupo de ajuste oclusal e 24 no grupo controle (p=0,672). Na avaliação de 24 horas, 18 e 19 indivíduos relataram dor (p=0,991) e, na avaliação de 72 horas, 8 e 4 relataram dor (p=0,219), respectivamente. O ajuste oclusal não influenciou a prevalência de dor pós-operatória após o tratamento endodôntico em dentes com pulpite irreversível sintomática.

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.

Endodontic Surgery Associated with Guided Tissue Regeneration Technique: Case Report / Cirurgia Parendodôntica Associada à Técnica de Regeneração Tecidual Guiada: Relato de Caso

Non-surgical endodontic retreatment should always be the first option for reintervention when the initial endodontic treatment fails. The surgical treatment, called periradicular surgery, will be the procedure of choice when there is no success after the conventional endodontic retreatment. The purpose of this article is to describe clinical case of endodontic surgery, associated with guided tissue regeneration (GTR). A male patient, 24 years old, was referred for endodontic surgery on tooth 12 after two unsuccessful endodontic interventions. During the surgery, osteotomy, lesion curettage, apicectomy, retrograde obturation with Mineral Trioxide Aggregate (MTA), and filling of the bone failure with lyophilized bone and reabsorbable collagen membrane were performed. After six months of follow-up, the patient did not present any type of painful symptomatology. The endodontic surgery, associated with a technique of guided tissue regeneration, was efficient to solve this clinical case. (AU)

O retratamento endodôntico não cirúrgico deve sempre ser a primeira opção de reintervenção quando o tratamento endodôntico inicial falha. Já o tratamento cirúrgico, ou cirurgia parendodôntica, será o procedimento de escolha quando não há sucesso após o retratamento endodôntico convencional. O objetivo deste artigo é descrever um caso clínico de cirurgia parendodôntica, associada à regeneração tecidual guiada (RTG). O paciente, gênero masculino, 24 anos, foi encaminhado para cirurgia parendodôntica no dente 12 após duas intervenções endodônticas sem sucesso. Durante a cirurgia foram realizadas manobras de osteotomia, curetagem da lesão, apicectomia, obturação retrógrada com Mineral Trióxido Agregado (MTA), além de preenchimento da falha óssea com osso liofilizado e membrana de colágeno reabsorvível. Após seis meses de acompanhamento do caso, o paciente não apresentou nenhum tipo de sintomatologia dolorosa. A cirurgia parendodôntica, associada à técnica de regeneração tecidual guiada, foi eficiente para solucionar este caso clínico. (AU).

Apical Transportation and Centering Ability After Root Canal Filling Removal Using Reciprocating and Continuous Rotary Systems: A CBCT Study.

OBJECTIVE: To evaluate the apical transportation and centering ability promoted by reciprocating and continuous rotary systems after root canal filling removal. MATERIALS AND METHODS: After obturation, 40 mesial root canals of mandibular molars were distributed into four groups (n = 20) for filling material removal: PTU group-F2 instrument (25.08) of ProTaper Universal system; R25 group-R25 instrument (25.08) of Reciproc system; X2 group-X2 instrument (25.06) of ProTaper Next system and X3 group-X2 instrument (25.06) of ProTaper Next system, followed by X3 instrument (30.07). Cone-beam computed tomographic analysis was performed before and after filling material removal for acquisition of apical images. Apical transportation (AT) and its direction, and centering ability (CA), were assessed using the equations AT = (X1-X2)-(Y1-Y2) and CA = (X1-X2/Y1-Y2 or Y1-Y2/X1-X2), respectively. Data were submitted to the nonparametric Kruskal-Wallis and Dunn multiple comparison tests (p < 0.05) for statistical analysis. RESULTS: There was no statistically significant difference among groups for AT (p > 0.05), with a tendency toward transportation in the distal direction. Also, there was no statistically significant difference among groups regarding CA (p > 0.05). CONCLUSIONS: The different systems, including ProTaper Next, caused AT within the acceptable clinical limit after filling removal. In addition, none of the tested systems presented adequate CA.

Effect of photobiomodulation therapy on postoperative pain after endodontic treatment: a randomized, controlled, clinical study.

OBJECTIVE: The aim of this prospective, randomized, clinical study was to assess the effect of photobiomodulation therapy (PBM) with low-level laser irradiation (LLLI) on postoperative pain after endodontic treatment. MATERIALS AND METHODS: Sixty patients, diagnosed with irreversible pulpitis in lower molar teeth, participated in the study. All treatments were performed by a single operator. Participants were randomly divided into two groups: in the experimental group (EG), endodontic treatment was performed with a reciprocating system, immediately followed by PBM with LLLI; and only endodontic treatment was performed in the control group (CG). Postoperative pain was assessed by a second examiner, who was blinded, using two scales: verbal rating scale (VRS) and numerical rating scale (NRS). Assessment was carried out at 6, 12, and 24 h after treatment. Data were analyzed using chi-squared, Fisher's exact, Mann-Whitney tests, ordinal, and non-parametric regression analyses. RESULTS: For the prevalence of pain, the difference between the groups was significant for the evaluations performed after 6 h (p = 0.04) and 24 h (p = 0.02). The difference after 24 h remained significant after stratification by sex and extrusion of filling material. Increased pain intensity was associated with extrusion of root canal filling material to the periapical region in the two scales used. CONCLUSION: The effect of PBM therapy after endodontic treatment showed a significant decreasein prevalence of postoperative pain. CLINICAL RELEVANCE: The PBM reduces the prevalence of postoperative pain and may benefit patients who need endodontic treatment.

Luxação extrusiva de um incisivo central Permanente jovem: relato de caso clínico / Extrusive luxation of an immature permanent central incisor: clinical case report

Objetivo: O objetivo deste artigo é apresentar o relato de um caso clínico de luxação extrusiva de dente permanente com rizogênese incompleta, onde não foi necessária a realização de intervenção endodôntica. Relato de caso: Paciente de 6 anos de idade compareceu ao serviço de urgência da Policlínica Odontológica da Universidade do Estado do Amazonas (UEA) para atendimento após queda durante atividade de lazer, apresentando traumatismo direto na boca. Foi informado durante a consulta inicial que o incidente havia ocorrido há cerca de três dias, e que o atendimento imediato logo após o trauma foi realizado em um Serviço de Pronto Atendimento, porém, nenhum tipo de procedimento na cavidade oral foi realizado. Após exames clínico e radiográfico observou-se que o dente 21 apresentava deslocamento parcial para fora do alvéolo dentário no sentido axial, com alteração da oclusão, dor local à palpação e mobilidade dentária. Foi realizada profilaxia da área afetada, e anestesia do dente luxado e tecidos adjacentes. O reposicionamento do dente foi realizado em seguida, pressionando-o e tracionando-o de forma suave e contínua até a sua correta posição dentro do alvéolo. A área afetada foi limpa com gaze estéril embebida em soro fisiológico, e foi instalada uma contenção rígida confeccionada com fio ortodôntico e resina composta. Conclusão: O reposicionamento da maneira adequada do dente traumatizado dentro do alvéolo dentário, num período de tempo hábil, seguido de sua proservação, permitiram a manutenção da vitalidade do tecido pulpar, e consequentemente, o desenvolvimento do segmento radicular.

Objective: The objective of this article is to present a clinical case of extrusive luxation of an immature permanent tooth, with no endodontic management. Case report: A 6-year-old patient was provided to emergency treatment at the State University of Amazonas, as a result of a fall, with a direct trauma to the mouth. It was informed during the initial consultation that the incidente has occurred three days after. Emergency examination had been carried out by an Emergency Service; however, any type of procedure in the oral cavity was performed in ths occasion. After clinical and radiographic examinations, it was observed that tooth 21 presented partial displacement from the alveolar socket in the axial direction, with occlusion alteration, local pain to palpation and dental mobility. Cleaning of the affected area and anesthesia of the dislocated tooth and adjacent tissues were performed. Then, tooth repositioning was performed by pressing and tracing it smoothly and continuously until its correct position within the alveolar socket. The affected area was cleaned with sterile gauze soaked in saline solution, and a rigid containment made of orthodontic wire and composite resin was installed. Conclusion: A proper repositioning of the traumatized tooth within the alveolar socket, followed by its clinical followup, allowed the pulp tissue to remain vital, and consequently, the complete development of the root portion

Effect of glide path on transportation promoted by NiTi and M-Wire instruments / Efeito do glide path no transporte promovido por instrumentos de NiTi e M-Wire

Objective: To evaluate the effect of glide path creation on transportation promoted by NiTi and M-Wire instruments. Material and Methods: Sixty polyester resin blocks containing a simulated root canal were distributed into four groups (n=15), according to the protocols/systems used for root canal preparation: GPR group - glide path + Revo-S system; R group - no glide path + Revo-S system; GPPN group - glide path + ProTaper Next system and PN group - no glide path + ProTaper Next system. Root canals were photographed before and after preparation, and the images were superimposed to evaluate the transportation at the apical, middle and coronal thirds. The time spent to perform preparation was also measured (seconds). Data were submitted to the non-parametric Kruskal-Wallis test (p0.05). GPR and R groups were similar in the middle third (p>0.05). However, the transportation value in GPR group was statistically higher in comparison with GPPN and PN groups (p0.05). Only R group presented significant difference in comparison with GPPN and PN groups (p0.05). Conclusion: None of the systems were capable of maintaining the original trajectory of the simulated root canal, and the glide path had no effect on the transportation promoted by instruments. (AU)

Objetivo: Avaliar o efeito do glide path no transporte promovido por instrumentos fabricados em NiTi e M-Wire. Material e Métodos: Sessenta blocos de resina poliéster contendo um canal simulado foram separados em quatro grupos (n=15), de acordo com os protocolos/ sistemas utilizados para realização do preparo: Grupo GPR - glide path + sistema Revo-S; Grupo R - sem glide path + sistema Revo-S; Grupo GPPN - glide path + sistema ProTaper Next e Grupo PN - sem glide path + sistema ProTaper Next. Os canais foram fotografados antes e após o preparo, e as imagens sobrepostas para avaliação do transporte nos terços apical, médio e cervical. O tempo para realização do preparo também foi mensurado (segundos). Os dados foram submetidos ao teste não-paramétrico de Kruskal-Wallis (p0,05). Os grupos GPR e R foram semelhantes no terço médio (p>0,05), entretanto, o transporte no grupo GPR foi estatisticamente maior em comparação aos grupos GPPN e P (p0,05). Somente o grupo R apresentou diferença em comparação aos grupos GPPN e PN (p0,05). Conclusão: Nenhum sistema foi capaz de manter a trajetória original do canal simulado, e o glide path não teve efeito sobre o transporte promovido pelos instrumentos.(AU)

Desvio apical promovido por sistemas rotatórios e reciprocantes: estudo piloto em canais simulados / Apical deviation promoted by rotary and reciprocating systems: pilot study in simulated canals

Objetivo: Instrumentos endodônticos de movimentos reciprocante estão entre as últimas inovações para o preparo do sistema de canais radiculares. O objetivo desse estudo piloto foi comparar o desvio apical promovido por sistemas reciprocantes e rotatório em canais simulados. Material e método: Quarenta e cinco canais simulados foram distribuídos aleatoriamente em três grupos experimentais (n=15), de acordo com o sistema utilizado para realização do preparo: Grupo PT - sistema ProTaper; Grupo RP - sistema Reciproc e Grupo WO - sistema WaveOne. O desvio apical foi avaliado por meio da análise de imagens obtidas pré e pós-instrumentação de cada canal simulado, com auxílio do programa ImageJ. Resultados: Todos os grupos apresentaram algum nível de desvio apical. O grupo PT apresentou maior desvio aos 2 mm, com diferença estatisticamente significante em relação aos demais grupos (p<0,05). Quando comparada a média dos 3 mm apicais, somente houve diferença significativa entre os grupos PT e RP (p<0,05). Conclusão: Nenhum dos sistemas testados, reciprocante ou rotatório, foi capaz de manter a posição original do forame apical após o preparo do canal simulado.

Objective: Endodontic instruments of reciprocating motion are among the latest innovations for root canal system preparation. The aim of this pilot study was to compare the apical deviation promoted by reciprocating and rotary systems in simulated canals. Methods: Forty-five simulated canals were randomly distributed into three experimental groups (n=15), according to the system used for preparation: PT group - ProTaper system; RP group - Reciproc and WO group - WaveOne system. The apical deviation was assessed by analysis of pre- and post-instrumentation images of each simulated canal, with the aid of the ImageJ software. Results: All groups presented some level of apical deviation. The PT group presented greater deviation at 2 mm, with statistically significant difference in comparison with the other groups (p<0.05). When compared the average of the final apical 3 mm, there was significant difference only between PT and RP groups (p<0.05). Conclusion: None of the tested systems, reciprocating or rotary, were able to maintain the original position of the apical foramen after preparation of the simulated canal.

Topographic and Chemical Analysis of Reciprocating and Rotary Instruments Surface after Continuous Use.

This study aimed at evaluating the changes in surface characteristics and NiTi content of reciprocating and rotary instruments after continuous use. Thirty brand-new instruments were assigned to 3 groups (n=10): PNX1 Group - ProTaper Next system - instrument X1; PNX2 Group - ProTaper Next system - instrument X2 and WO Group - WaveOne system - Primary instrument 25.08. The instruments were used to prepare 60 simulated root canals. Analysis of surface characteristics by scanning electron microscopy (SEM) and chemical analysis of Ni and Ti content by energy-dispersive spectroscopy (EDS) were performed before and after the first and third use of the instruments. Only WO Group had significant increase in the quantity of defects and deformations after the third use (p<0.05). PNX1 Group had significant decrease in Ni content after the third use, in comparison with the unused instruments (p<0.05). PNX1 Group had no decrease in Ti content throughout the time of use (p>0.05), however, in PNX2 Group, there was significant decrease in the different time interval of analysis (p<0.05). Continuous use promoted increase in defects and deformations only for WaveOne instruments. Chemical composition presented significant changes according to the time of instruments use.

Topographic and Chemical Analysis of Reciprocating and Rotary Instruments Surface after Continuous Use

Abstract This study aimed at evaluating the changes in surface characteristics and NiTi content of reciprocating and rotary instruments after continuous use. Thirty brand-new instruments were assigned to 3 groups (n=10): PNX1 Group - ProTaper Next system - instrument X1; PNX2 Group - ProTaper Next system - instrument X2 and WO Group - WaveOne system - Primary instrument 25.08. The instruments were used to prepare 60 simulated root canals. Analysis of surface characteristics by scanning electron microscopy (SEM) and chemical analysis of Ni and Ti content by energy-dispersive spectroscopy (EDS) were performed before and after the first and third use of the instruments. Only WO Group had significant increase in the quantity of defects and deformations after the third use (p<0.05). PNX1 Group had significant decrease in Ni content after the third use, in comparison with the unused instruments (p<0.05). PNX1 Group had no decrease in Ti content throughout the time of use (p>0.05), however, in PNX2 Group, there was significant decrease in the different time interval of analysis (p<0.05). Continuous use promoted increase in defects and deformations only for WaveOne instruments. Chemical composition presented significant changes according to the time of instruments use.

Resumo Este estudo teve como objetivo avaliar as alterações nas características de superfície e teor de NiTi de instrumentos reciprocantes e rotatórios após uso contínuo. Trinta instrumentos novos foram separados em três grupos (n=10): Grupo PNX1 - ProTaper Next system - instrumento X1; Grupo PNX2 - ProTaper Next system - instrumento X2 e Grupo WO - WaveOne system - instrumento Primary 25.08. Os instrumentos foram utilizados para o preparo de 60 canais radiculares simulados. Análise por microscopia eletronica de varredura (MEV), a análise química do conteúdo de Ni e Ti por espectroscopia de energia dispersiva (EED) foram realizadas antes e após o primeiro e terceiro uso dos instrumentos. Apenas o Grupo WO apresentou aumento significativo na quantidade de defeitos e deformações após o terceiro uso (p<0,05). O grupo PNX1 teve diminuição significativa no teor de Ni após o terceiro uso, em comparação aos instrumentos não utilizados (p<0,05). O grupo PNX1 não apresentou diminuição do teor de Ti ao longo do tempo de uso (p>0,05), no entanto, no Grupo PNX2, houve diminuição significativa nos diferentes intervalos de tempo de análise (p<0,05). O uso contínuo promoveu aumento nos defeitos e deformações somente para os instrumentos WaveOne. A composição química apresentou alterações significativas de acordo com o tempo de uso dos instrumentos.

Assessment of a Cavity to Optimize Ultrasonic Efficiency to Remove Intraradicular Posts.

INTRODUCTION: The study assessed an in vitro protocol for the removal of cast metal posts using ultrasonic vibration in multirooted teeth by drilling a cavity in the coronal portion of the post followed by ultrasound application in the cavity. METHOD: Forty endodontically treated molars received intraradicular cast posts and were divided into 4 groups according to the removal protocol: the control group, no cavity and no ultrasonic vibration; the ultrasonic group, no cavity and ultrasonic vibration in the coronal portion of the core; the cavity group, a cavity in the core and no ultrasonic vibration; and the cavity ultrasonic group, a cavity in the core and ultrasonic vibration inside the cavity. The traction test was performed on all samples using a universal testing machine (EMIC DL-2000; EMIC Equipamentos e Sistemas de Ensaio LTDA, São José dos Pinhais, PR, Brazil) at a speed of 1 mm/min, obtaining values in Newtons. The data were statistically analyzed using analysis of variance and the Tukey-Kramer test (P < .05). RESULTS: The results showed statistically significant differences between the tested groups (control group = 322.74 N, ultrasonic group = 283.09 N, cavity group = 244.00 N, and cavity ultrasonic group = 237.69 N). The lowest mean strength was found in the group that received ultrasonic vibration inside the cavity. CONCLUSIONS: Preparing a cavity in the coronal core followed by ultrasonic vibration reduces the traction force required for removal. The removal protocol was effective for removing posts in multirooted teeth cemented with zinc phosphate.

Technological advances in endodontics: treatment of a mandibular molar with internal root resorption using a reciprocating single-file system.

The field of endodontics has become increasingly successful due to technological advances that allow clinicians to solve clinical cases that would have been problematic a few years ago. Despite such advances, endodontic treatment of teeth with internal root resorption remains challenging. This article presents a clinical case in which a reciprocating single-file system was used for endodontic treatment of a mandibular molar with internal root resorption. Radiographic examination revealed the presence of internal root resorption in the distobuccal root canal of the mandibular right first molar. A reciprocating single-file system was used for root canal instrumentation and final preparation, and filling was obtained through a thermal compaction technique. No painful symptoms or periapical lesions were observed in 12 months of follow-up. The results indicate that a reciprocating single-file system is an adequate alternative for root canal instrumentation, particularly in teeth with internal root resorption.

Filling Material Removal with Reciprocating and Rotary Systems Associated with Passive Ultrasonic Irrigation.

OBJECTIVE: The purpose of this ex vivo study was to evaluate the filling material removal ability, and the time required to perform this procedure, of reciprocating and conventional rotary systems when associated with passive ultrasonic irrigation. METHODS: The palatal roots of 40 maxillary molars were submitted to root canal preparation and filling. The desobturation of root canals was initially performed with Largo burs in the coronal portion (4 mm) to drill the gutta-percha and to facilitate the action of the instruments used then. Next, the palatal roots were randomly distributed (n=10) according to the systems and irrigation protocols used for filling material removal: ProTaper universal retreatment (PTR), PTR+passive ultrasonic irrigation (PUI) (PTR+PUI), Reciproc system (RS), and RS+PUI. Passive ultrasonic activation was performed in the root canals completely filled with 2.5% sodium hypochlorite solution using a smooth and straight ultrasonic tip, coupled to a low-power (20%) ultrasonic device for 1 min (3 cycles of 20 s). After retreatment, the roots were longitudinally sectioned to the remaining filling material quantification using an operating microscope. Environmental scanning electron microscopy (ESEM) micrographs at 97, 105, and 250 X magnifications were also taken to evaluate the quantity of filling material present at the apical portion of the palatal roots. RESULTS: The RS group presented greater quantity of filling material attached to the root canal walls than the other groups (P>0.05). PTR+PUI and RS+PUI groups were statistically similar (P>0.05). Reinstrumentation of root canals using RS was faster than PTR, irrespective of the irrigation protocol used (P>0.05). CONCLUSION: The association between PUI and the different systems for reinstrumentation yielded greSater filling material removal. The reciprocating system was faster.

Cleaning Effectiveness of a Reciprocating Single-file and a Conventional Rotary Instrumentation System.

OBJECTIVE: To compare cleaning effectiveness by histological analysis of a reciprocating single-file system with ProTaper rotary instruments during the preparation of curved root canals in extracted teeth. METHODS: A total of 40 root canals with curvatures ranging between 20 - 40 degrees were divided into two groups of 20 canals. Canals were prepared to the following apical sizes: Reciproc size 25 (n=20); ProTaper: F2 (n=20). The normal distribution of data was tested by the Kolmogorov-Smirnov test and the values obtained for the test (Mann-Whitney U test, P < .05) were statistically analyzed using the GraphPad InStat for the Mac OS software (GraphPad Software, La Jolla, CA, USA). RESULTS: There were no significant differences in remaining debris (P > .05) between the two groups. CONCLUSION: The application of reciprocating motion during instrumentation did not result in increased debris when compared with continuous rotation motion, even in the apical part of curved canals. Both instruments resulted in debris in the canal lumen, irrespective of the movement kinematics applied.

Assessment of postoperative pain after reciprocating or rotary NiTi instrumentation of root canals: a randomized, controlled clinical trial.

OBJECTIVES: The aim of this study was to assess postoperative pain in a prospective randomized clinical trial comparing two groups, using the Reciproc® system in one group and the ProTaper® rotary system in the other. MATERIAL AND METHODS: The study included 78 male patients, aged 18-64 years (mean age of 26 years), with asymptomatic pulp necrosis in mandibular molar teeth (n = 78). The single-session endodontic treatment was performed by a single operator specialized in Endodontics. Mechanical preparation of the root canals was performed using the ProTaper® and Reciproc® instrumentation techniques. Postoperative pain was recorded using a verbal rating scale (VRS) and verbal description with well-defined categories at the three following time intervals: 24 h, 72 h, and 7 days after the endodontic procedure. The assessment of postoperative pain was recorded as no pain, mild pain, moderate pain, and severe pain or flare-up. Data were analyzed using the nonparametric Mann-Whitney test with the aid of the STATA® software. RESULTS: The incidence of postoperative pain in the ProTaper group (PT) 24 h after the endodontic procedure was 17.9 and 5.1 % after 72 h. In the Reciproc group (RP), the incidence after 24 h was 15.3 and 2.5 % after 72 h. No patients presented severe pain at the time intervals assessed. CONCLUSIONS: No significant difference (p > 0.05) in postoperative pain was found between the ProTaper® and Reciproc® instrumentation technique during endodontic treatment in this study. CLINICAL RELEVANCE: According to our findings and the results of the clinical trial, the occurrence of postoperative pain was low and similar between the reciprocating and rotary techniques during the time intervals assessed. These results are different from basic laboratory studies that affirm that the reciprocating techniques tend to promote more postoperative pain since extrusion of debris is greater.

Endodontic treatment of maxillary lateral incisor with internalroot resorption using a hybrid instrumentation technique -case report / Tratamento endodôntico de incisivo lateral superior com reabsorção radicular interna utilizando uma técnica de instrumentaçãohíbrida - relato de caso

Several factors influence the cleaning and shaping capacity of instrumentation techniques, such as internal resorption areas. Internal root resorption contributes to failure of endodontic treatment, since debris may remain attached to dentine walls, and the instruments are not able to completely remove them. This paper reports a clinical case of endodontic treatment of a tooth with internal root resorption using a hybrid instrumentation technique. After clinical and radiographic examinations, pulp necrosis with periapical lesion, and the presence of an internalroot resorption were diagnosed. Biomechanical preparation began with glide path creation with sizes15 and 20 K-type files. Apical third instrumentation was performed with rotary ProFile files #25.04 upto #35.04, followed by root canal filling. The casewas followed-up for twelve months. Progressive bone repair was observed radiographically. Despitethe presence of internal root resorption, theresults achieved with the hybrid technique suggest effectiveness in this clinical case solution...

Diversos fatores influenciam a capacidade de limpezae modelagem das técnicas de instrumentação, como áreas de reabsorção interna. A reabsorção radicular interna contribue para falhas no tratamento endodôntico, uma vez que detritos podem permanecer aderidos as paredes dentinárias, e os instrumentos não são capazes de removê-los completamente. O objetivo deste estudo foi relatar um caso clínico de tratamento endodôntico de incisivo lateral superior com reabsorção interna empregando uma técnica híbrida de instrumentação. Após exames clínico e radiográfico, o diagnóstico foi de necrose pulpar com lesão periapical, além da presença de reabsorção radicular interna. O preparo biomecânico teve início com exploração inicial com limas tipo K #15 e #20. O preparo do terço apical foi realizado com instrumentos rotatórios Pro File #25.04 à #35.04,seguido de obturação. O acompanhamento do caso foi realizado por doze meses. Radiograficamente foi possível observar progressiva reparação óssea.Apesar da presença de reabsorção radicular interna,a técnica de instrumentação híbrida foi eficaz na resolução do caso...