Canal transportation and centering ability of curved root canals prepared using rotary and reciprocating systems

Abstract Aim: To evaluate canal transportation and centering ability of Protaper and WaveOne systems in curved root canals by cone-beam computed tomography. Methods: Twenty human molars were randomly divided into two groups according to the system used: Group GP (ProTaper Universal(r)) and group GW (WaveOne(tm)). CT scans were performed before and after the chemo-mechanical preparation on three points: 2 mm, 3 mm and 4 mm from the tooth apex. The cuttings in dentin were measured and results were statistically analyzed. Results: In GP, there was higher percentage in transport at 2 mm and 4 mm toward the mesial wall of the tooth root compared to GW (p<0.05). There was no difference between the systems regarding their centering ability. Conclusions: None of the systems was able to touch all the dentin walls and stay centered during the chemical-mechanical preparation.

Avaliação da infiltração marginal de quatro seladores provisórios após a utilização de substâncias químicas auxiliares da instrumentação endodôntica / Evaluation of marginal leakage of four temporary materials after using irrigating solutions in endodontic treatment

O selamento coronário, juntamente com a obturação do canal radicular, possibilita um ambiente propício ao reparo dos tecidos periapicais, epílogo do tratamento endodôntico. Além disso, um bom selamento temporário impede que haja recontaminação entre as possíveis sessões do tratamento endodôntico, resguardando também a medicação intracanal. Muitos estudos têm sido realizados para investigar o vedamento marginal das restaurações temporárias. Este trabalho se propõe a avaliar a infiltração marginal na porção coronária de dentes que sofreram ação das substâncias químicas usadas no tratamento endodôntico, selados com quatro diferentes materiais provisórios. Para tanto, foram utilizados 60 pré-molares humanos hígidos, divididos em 5 grupos experimentais, conforme o material selador provisório empregado (Bioplic , Coltosol , XTempLC, IRM, Coltosol + Ação das substâncias químicas) , e 2 grupos-controle. Os resultados obtidos indicaram que todos os materiais restauradores temporários avaliados permitiram certo grau de infiltração, sendo o Grupo II (Coltosol) aquele que apresentou o menor índice. Constatou-se também que as substâncias químicas auxiliares empregadas durante o preparo químico mecânico podem influenciar no selamento marginal, aspecto observado no Grupo V que apresentou infiltração coronária estatisticamente mais significante.

The coronary sealing, next to root canal obturation, permits an appropriate environment to the periapical tissues repair, which is the major endodontic treatment’s outcome. Furthermore, good temporary sealing prevents new contamination between sessions of the endodontic treatment, also protecting the intracanal dressing. Many studies have been achieved for examining the marginal sealing of temporary restorations. This study intended to evaluate the marginal leakage in the coronary portion of teeth which suffered action of irrigating solutions used in endodontics, sealed with four different temporary materials. Sixty entire human premolars were divided into 5 experimental and 2 control groups according to each temporary restorative material used (Bioplic, Coltosol, XTempLC, IRM, Coltosol + instrumentation). The results indicated that all temporary materials used allowed a certain degree of infiltration, however, Group II (Coltosol) showed the least index. It was also observed that irrigating solutions used during biomechanical preparation can influence the marginal sealing, such as that observed in Group V which presented the greatest significant marginal leakage.