ABSTRACT
Abstract: This study measured the thickness of cementum/dentin in the danger zone of the mandibular molars after root canal preparation using novel cone-beam computed tomography (CBCT) software. Eighty-four teeth were distributed into four groups: ProTaper Next, BioRace, Reciproc Blue, and WaveOne Gold. E-Vol DX® CBCT software was used to measure initial and final remaining cementum-dentin thicknesses after root canal preparation of the mesial root of mandibular molars at 1 and 3 mm from the furcation. The Kolmogorov-Smirnov test was used to test variable symmetry. The variables were described as mean and standard deviations, compared among the groups using analysis of variance (ANOVA), and within the groups using the Student t test. A generalized estimating equation model was used to compare the variation before and after root canal preparation. The level of significance was set at 5%. Differences between mean initial and final thicknesses of the mesiobuccal (MB) and mesiolingual (ML) canals were not statistically significant. The mean initial thickness was 3 mm (0.900 mm ± 0.191), considering that a mean lower than 1 mm (1.035 mm ± 0.184) indicates the danger zone. Although cementum/dentin is thinner at 3 mm from the furcation (0.715±0.186) after root canal preparation, the greatest amount of dentin removed was found at 1 mm (0.734 ± 0.191). The cementum-dentin remaining after preparation was thicker than 0.715 mm in root canals prepared using #35 (WaveOne Gold®) and #40 (ProTaper Next®, BioRace® and Reciproc Blue®) instruments. This confirms the safety of canal preparation in the danger zone using these systems.
ABSTRACT
Objetivo: o objetivo do estudo foi avaliar a ocorrência de transporte do canal radicular após o preparo com instrumentos de níquel-titânio (NiTi) de rotação contínua, por meio do exame de tomografia computadorizada de feixe cônico (TCFC). Material e método: Canais mesiovestibulares e mesiolinguais de vinte molares inferiores humanos foram distribuídos aleatoriamente em dois grupos experimentais (n=10), de acordo com o sistema rotatório de NiTi: Grupo 1 BioRace; e Grupo 2 - ProTaper Next. Imagens de TCFC foram obtidas antes do preparo do canal radicular (TCFC 1) e após o uso dos instrumentos BR2 (#25/.04) e X2 (#25/.06) (TCFC 2) e BR5 (#40/.04) e X4 (#40/.06) (TCFC 3). Dois examinadores avaliaram todas as imagens determinando a ocorrência ou não de transporte do canal radicular. Foram estabelecidos 3 níveis para a mensuração nas imagens: 1-2 mm aqueÌm do veÌrtice radicular (terço apical); 3-4 mm aqueÌm do veÌrtice radicular (terço médio); 4- 2 mm abaixo da furca (terço cervical). Os dados foram analisados utilizando o teste de Kruskal-Wallis com pós-teste de Dunn para comparações múltiplas. O nível de significância foi de 5%. Resultados: Os canais radiculares preparados com o sistema BioRace não apresentaram transporte (P<0,05). Foi observado transporte apenas no terço apical do canal mesiovestibular após o uso do instrumento ProTaper Next X4 (#40/.06) (P<0,05). Conclusão: O sistema BioRace permitiu a ampliação dos canais mesiovestibular e mesiolingual de molares inferiores até o diâmetro cirúrgico 40 sem resultar em transporte do canal.
Aim: This study evaluated root canal transportation after root canal instrumentation with two nickel-titanium (NiTi) rotary systems, by using cone beam computed tomography (CBCT) imaging. Material and Methods: Mesiobuccal and mesiolingual root canals of twenty human mandibular molars were randomly divided into two experimental groups (n = 10), according to the NiTi rotary system: Group 1 BioRace; and Group 2 ProTaper Next. CBCT scans were obtained before the root canal instrumentation (CBCT 1) and after the use of BR2 (#25/.04) and X2 (#25/.06) instruments (CBCT 2) and after the use of BR5 (#40/.04) and X4 (#40/.06) instruments (CBCT 3). Two examiners evaluated the occurrence or not of transportation. Measurements were made at 3 different points: 1-2 mm from the apex (apical third); 3-4 mm from the apex (middle third); 4- 2 mm below furcation (cervical third). The Kruskal-Wallis and Dunn tests were used for statistical analysis. The level of significance was set at 5%. Results: Root canals instrumented with BioRace instruments showed no transportation (P<0.05). Transportation was observed only in the apical third of the mesiobuccal root canal after the use of ProTaper Next X4 instrument (#40/.06) (P<0.05). Conclusions: The BioRace system allowed the widening of mesiobuccal and mesiolingual root canals of mandibular molars up to apical diameter 40 without resulting in root canal transportation.
ABSTRACT
Objetivo: avaliar o desgaste dentinário promovido por instrumentação rotatória com diferentes sistemas de NiTi e instrumentação manual em raízes mesiais de molares inferiores. Material e Métodos: Foram selecionados 60 molares inferiores extraídos que foram divididos em 6 grupos (n=10). Nos grupos A, B, C e D os canais radiculares foram preparados utilizando-se os sistemas de NiTi ProFile®, ProTaper Universal®, K3® e Race®, respectivamente. No grupo E, os canais radiculares foram preparados com limas manuais do tipo K Flexofile®, e no grupo F os canais radiculares não foram preparados (controle). Após os preparos, foram realizados dois cortes perpendiculares ao longo eixo da raiz mesial, sendo um no terço cervical e outro no terço apical. As imagens dos cortes foram capturadas por meio de microscópio e analisadas através de software. Para cada corte, foram realizadas três medidas correspondentes à menor espessura da parede dentinária, sendo obtida uma média de cada espécime. As comparações entre os grupos das medidas obtidas foram realizadas pelo teste t, com nível de significância de 5%. Resultados: Tanto no terço cervical quanto apical houve diferença significante entre o grupo E (Flexofile) e os grupos de sistemas de NiTi, bem como entre o grupo controle. No terço apical foi observada diferença significante entre o grupo A (Profile®) e o grupo D (Race®) em comparação ao grupo controle. Conclusões: Pôde-se concluir que as técnicas que utilizaram instrumentos de NiTi preservaram mais estrutura dentinária quando comparados à técnica que se utilizou de limas manuais.
Objective: to evaluate dentinal wear promoted by rotary instrumentation with different NiTi systems and manual instrumentation in mesial roots of lower molars. Material and Methods: Sixty extracted lower molars were selected and divided into 6 groups (n = 10). In groups A, B, C and D the root canals were prepared using the NiTi ProFile®, ProTaper Universal®, K3® and Race® systems, respectively. In group E, the root canals were prepared with manual files of type K Flexofile®, and in group F the root canals were not prepared (control). After the preparation, two perpendicular cuts were made along the axis of the mesial root, one in the cervical third and the other in the apical third. The images of the cuts were captured by means of a microscope and analyzed through software. For each cut, three measurements were made corresponding to the lowest thickness of the dentin wall, obtaining an average of each specimen. The comparisons between the groups of measures obtained were performed by the t test, with a significance level of 5%. Results: In both the cervical and apical thirds there was a significant difference between the group E (Flexofile) and the groups of NiTi systems, as well as between the control group. In the apical third, a significant difference was observed between group A (Profile®) and group D (Race®) compared to the control group. Conclusions: It could be concluded that the techniques that used NiTi instruments preserved more dentin structure when compared to the technique used of manual files.
ABSTRACT
A persistência da lesão periapical pode estar relacionada à complexidade do sistema de canais e aos fatores extrarradiculares. Com o intuito de reduzir os fracassos endodônticos, a revolução técnico-científica juntamente com o aperfeiçoamento e aprimoramento profissional, a cirurgia parendodôntica soluciona problemas que não puderam ser resolvidos pelo tratamento endodôntico convencional, ou quando este não é possível. Neste trabalho, há o relato de caso clínico de lesão periapical envolvendo os dentes 11 e 12 em que se optou pela realização do retratamento e tratamento endodôntico dos dentes acometidos, seguido de procedimento cirúrgico. O objetivo é descrever um caso de tratamento e retratamento endodôntico seguido de cirurgia parendodôntica utilizando a apicectomia como modalidade cirúrgica. Com acompanhamento clínico e radiográfico pode-se concluir que em caso de lesões persistentes, a cirurgia parendodôntica se mostra uma boa alternativa para o reparo tecidual e eliminação da infecção.
The persistence of periapical lesions may be related to the complexity of the canal system and extra-radicular factors. In order to reduce endodontic failures, the technical-scientific revolution in conjunction with professional improvement, parendodontic surgery solves problems that could not be resolved by conventional endodontic treatment, or when this is not possible. This study reports a clinical case of periapical lesion involving the teeth 11 and 12 in which the endodontic retreatment and conventional endodontic treatment of the affected teeth were chosen, followed by a surgical procedure. The purpose is to describe a case of endodontic retreatment and conventional treatment followed by parendodontic surgery using apicectomy as surgical modality. It can be concluded that with the clinical and radiographic follow-up of persistent lesion cases parendodontic surgery may be a good alternative to tissue repair and elimination of infection.