Does the ultrasonic activation of sealer hinder the root canal retreatment?

OBJECTIVES: To evaluate if the ultrasonic activation of sealer hinders the root canal retreatment. MATERIALS AND METHODS: Thirty mandibular premolars were prepared using the ProTaper Universal system (Dentsply) until the instrument F3 (0.30/0.09). The canals were distributed into 2 groups (n = 15), according to the filling technique: NUact group - sealer without ultrasonic activation + gutta-percha cones and Uact group - sealer with ultrasonic activation + gutta-percha cones. The canals were re-instrumented with Largo burs, followed by the instrument R50 (0.50/0.05) of the Reciproc system. The time required to perform re-instrumentation was recorded (s). The roots were longitudinally cleaved, and the total area of root canal and remaining filling material were quantified (%). The ANOVA test was applied to the data and complemented by Student's t test (P < 0.05). RESULTS: Uact group had higher percentage of remaining filling material than NUact group (P < 0.05). When the root thirds were considered, there was statistically significant difference only for Uact group at the apical third (P < 0.05). There was no difference between groups regarding the time required to perform re-instrumentation (P > 0.05). CONCLUSIONS: Ultrasonic activation of sealer leads to a higher percentage of remaining filling material attached to the root canal walls. However, it did not affect the retreatment time. CLINICAL SIGNIFICANCE: Ultrasonic activation increases sealer penetration into dentinal tubules, improving its resistance to dislodgement. However, there is no scientific evidence to prove if ultrasonic activation of sealer hinders its removal when root canal retreatment is necessary.

Adhesive reattachment rehabilitating a nonvital central incisor with a complicated crown-root fracture: 1-year follow-up.

Dental trauma requires immediate treatment. However, some conventional treatments (such as an implant and/or partial fixed denture) will not always be immediately possible, due to the patient's age (mainly in pediatric cases) or lack of immediate financial resources. In such situations, the technique of adhesive reattachment plays an important role as a treatment option in the interim. This case report describes the use of adhesive fragment reattachment in the rehabilitation of a maxillary central incisor with a complicated crown-root fracture. A 1-year follow-up affirmed that the adhesive reattachment efficiently resolved the crown-root fracture, allowing for the retention of the tooth structure. This more conservative multidisciplinary approach restored function, esthetics, and self-esteem to the patient, while preserving all bone and gingival architecture for future implant treatment.

Apical transportation of manual NiTi instruments and a hybrid technique in severely curved simulated canals.

AIM: To evaluate the apical transportation induced by two instrumentation techniques in severely curved simulated canals. MATERIALS AND METHODS: Forty simulated canals were divided into two groups (n = 20), according to the following instrumentation techniques: ProTaper Universal Manual System and a hybrid technique. The simulated canals in the ProTaper group were prepared following the technique recommended by the manufacturer: SX files in the cervical third of the root canal and S1, S2, and F1 files up to the working length. In the hybrid group, preparation was performed with K-files sizes 15, 20, and 25 to the working length, followed by cervical preparation with Gates Glidden burs 1, 2, and 3. Apical finishing was performed with the ProTaper manual files S2 and F1. To analyze apical transportation, the simulated canals were photographed before and after preparation at ×8. The images of the root canals pre- and post-instrumentation were superimposed to measure the distance between the inner and outer walls along the first 3 mm of the apical third. RESULTS: The hybrid group presented the highest apical transportation values; however, with no statistically significant difference in comparison with the ProTaper group (P > 0.05). CONCLUSIONS: Both techniques induced similar apical transportation in the original path of the simulated root canals.

Contamination of absorbent paper points in clinical practice: a critical approach.

This study sought to evaluate the contamination level of absorbent paper points used routinely in dental clinical practice. For this study, 60 absorbent paper points were collected and separated into 3 groups: 20 paper points from sealed commercial packages (Group 1), 20 paper points from open commercial packages in use for 30 days (Group 2), and 20 paper points from a sealed commercial package that were manipulated by the operator (Group 3). Evaluation criteria was the presence or absence of turbidity in the brain heart infusion (BHI) broth used as the culture medium. The results (Kruskal-Wallis test; significance level = 5%) demonstrated bacterial growth in most of the samples for all groups, with a statistically significant difference in Group 3 compared to Groups 1 and 2. It was concluded that inadequate manipulation of paper points by the operator caused these materials to become contaminated; in addition, the bacterial growth in absorbent paper points that are still in their commercial packages indicates the importance of sterilization before the paper points are used in clinical practice.