Effect of sonic and ultrasonic activation on physicochemical properties of root canal sealers

Objective: To evaluate the effect of ultrasonic and sonic activation on physicochemical properties of AH Plus, MTA Fillapex, ADSeal, GuttaFlow Bioseal, and GuttaFlow 2 sealers. Methodology: Three experimental groups were formed: no activation (NA), ultrasonic activation (UA), and sonic activation (SA). The sealers were manipulated according to the manufacturers’ instructions. A 3-mL syringe was adapted to receive 1 mL of sealer. Activation was performed with a 20/.01 ultrasonic insert (20 s/1W) in the UA group. A size 35.04 sonic tip was used (20 s/10,000 cycles/min-1) in the SA group. The molds for physicochemical analysis were filled and evaluated according to ANSI/ADA specification no. 57: setting time (ST), flow (FL), dimensional change (DC), solubility (SB), and radiopacity (RD). Statistical analysis was performed by Kruskal-Wallis, one-way ANOVA, and Tukey's tests (P<0.05). Results: Regarding ST, only AH Plus and GuttaFlow 2 in the NA group met the ANSI/ADA standards. All FL values were greater than 20 mm in diameter, as determined by ANSI/ADA. The tested sealers and protocols did not comply with the ANSI/ADA standards for DC. As for SB, only MTA Fillapex, regardless of the activation protocol, did not follow the ANSI/ADA standards. All of the investigated sealers, regardless of the activation protocol, presented radiographic density higher than 3 mm Al, as proposed by ANSI/ADA. Conclusions: UA and SA promoted changes in the physicochemical properties of the evaluated root canal sealers, mainly in ST and F. Thus, it is important to evaluate the physicochemical properties of endodontic sealers associated with activation techniques prior to clinical application in order to determine whether the properties follow the parameters set by ANSI/ADA, ensuring safety and quality of root canal filling

Evaluation of the removal of different filling materials using reciprocating system followed by two supplementary techniques in flattened root canals

O objetivo do presente estudo foi avaliar, por meio de microtomografia computadorizada (micro-CT), o volume de remanescente de diferentes materiais obturadores (AH Plus e BC Sealer), após o uso do instrumento R50 e de técnicas complementares (inserto ultrassônico e instrumento XP-endo Finisher R) em canais radiculares ovais. Vinte e oito raízes distais de molares inferiores, com canal único e oval, foram selecionadas por micro-CT, preparados com instrumento R40 (40.06), e obturados com os seguintes cimentos: AH Plus (n = 14) e BC Sealer (n = 14), e submetidos à ciclagem térmica. Em seguida foi realizada a remoção inicial com R50 e os dentes foram escaneados no micro-CT para determinação do volume remanescente inicial de material obturador, e posterior complementação com inserto ultrassônico (n = 7) ou XP-endo Finisher R (n = 7). Os espécimes foram novamente escaneados, e a partir do volume inicial de material obturador (volinicial) e volume de material obturador remanescente (volrem) em mm3, obteve-se a % de volume de material remanescente após as técnicas de complementação (%volrem=volrem×100/volinicial). Para a análise qualitativa, as imagens de MEV e os modelos tridimensionais obtidos por micro-CT, foram avaliados em relação à presença/ausência e localização do remanescente de material obturador nos canais radiculares. Os dados de %volrem e volume remanescente de material obturador após o uso do instrumento R50 (%volR50) foram comparados pelo teste T, e os dados de %volrem foram submetidos ao teste ANOVA, seguido de teste de Tukey (nível de probabilidade de 95%). Considerando o canal como um todo, as técnicas de complementação promoveram redução significativa do volume remanescente de material obturador, sendo que menores valores foram observados quando utilizado o inserto ultrassônico (8,93 ± 6,12) em relação ao XP-endo Finisher R (16,26 ± 14,71) (P = 0,043). Quanto aos cimentos, pode-se observar que o BC Sealer apresentou maiores quantidades de remanescente (18,87 ± 13,42) quando comparado ao cimento AH Plus (6,33 ± 4,25) (P 0,05). Entretanto, ao se utilizar inserto ultrassônico e cimento AH Plus, maiores valores de volume de material remanescente foram observados no terço apical (23,08 ± 18,1) (P 0.05). However, when using ultrasonic tip and AH Plus, higher values were observed in the apical third (23.08 ± 18.1) (P 0.05). However, when using ultrasonic tip and AH Plus, higher values were observed in the apical third (23.08 ± 18.1) (P <0.001), and when the BC Sealer was used, in the middle third 15.53 ± 6.0) (P = 0.022). It was concluded that supplementary techniques increased the removal, however, none of the techniques completely removed the root canal filling material, especially when the tooth was filled with BC Seale

The challenges of treating a fused tooth

This paper describes and discusses the multidisciplinary treatment involving a permanent maxillary lateral incisor fused to a supernumerary tooth, both presenting pulp necrosis and periapical lesion. A 15-year-old male patient sought treatment complaining of pain, swelling and mobility on the maxillary right lateral incisor. After clinical and radiographic examination, root canal preparation was performed according to the crown-down technique and a calcium hydroxide dressing was placed for 15 days. The patient returned and the definitive endodontic filling was done with thermomechanical compaction of gutta-percha and sealer. After 18 months, clinical and radiographic examinations were carried out and no pain or swelling was reported. Two years after endodontic treatment, the patient returned for periodontal and cosmetic treatments. Nine months later, a cone-beam computed tomography (CBCT) revealed that the previously detected periodontal defect and periapical lesion were persistent. Apical endodontic surgery was indicated. The supernumerary tooth was removed, the communicating distal surface was filled and the surgical site received bioactive glass and demineralized bovine organic bone. The pathological tissue was submitted to histopathological examination and the diagnosis was periapical cyst. One year after the apical endodontic surgery, CBCT showed bone formation at maxillary lateral incisor apical area. Two years after the surgery, the restoration was replaced due to aesthetic reasons and periapical radiograph showed success after 5 years of treatment. A correct diagnosis and establishment of an adequate treatment plan resulted in a successful management of the case

Influence of root dentin treatment on the push-out bond strength of fibre-reinforced posts

Abstract This study evaluates the influence of root dentin treatment with NaOCl alone and combined with EDTA, with and without ultrasound activation, on the push-out bond strength (BS) of fiber-reinforced posts in weakened roots, cemented with RelyX or Panavia. The root canals of 42 maxillary canines were instrumented with Reciproc and 2.5% NaOCl. In the coronal 12mm of all canals, experimental weakening of the roots was produced by reducing dentin thickness with 2.44mm diameter diamond burs. The roots were assigned to 3 groups (n = 14) according to root dentin treatment: 2.5% NaOCl; 2.5% NaOCl + 17% EDTA; and 2.5% NaOCl + 17% EDTA, with solutions agitated using passive ultrasonic irrigation. After cementation of the fiber-reinforced posts the roots were divided in thirds. The first slice of each third was used for the push-out BS test, the second slice for confocal laser scanning microscopy and dentin microhardness (Knoop) analysis. Data were analysed by a two-way ANOVA and Tukey test (a = 0.05). NaOCl + EDTA provided highest BS values than NaOCl (p < 0.0001). Specimens cemented with Panavia presented significantly higher BS than those with RelyX in the three root thirds (p < 0.0001). The highest BS values occurred in the cervical third (p < 0.001). Ultrasound-activated NaOCl + EDTA promoted the greatest reduction in dentin microhardness, followed by NaOCl/EDTA and NaOCl. Ultrasonic activation of NaOCl and EDTA reduced root dentin microhardness, but did not improve the push-out BS of resin-based cements. Panavia presented higher BS than RelyX. RelyX was not influenced by the root dentin treatment protocols

Effectiveness of different final irrigation techniques and placement of endodontic sealer into dentinal tubules

<div><p>Abstract: The aim of this study was to compare two irrigation techniques and four devices for endodontic sealer placement into the dentinal tubules. Ninety-nine single-rooted human teeth were instrumented and allocated to either the control (CO) (n=11) or experimental groups according to the irrigation method: syringe and NaveTip needle (NT) (n=44), and EndoActivator (EA) (n=44). These groups were subdivided according to sealer placement into K-File (KF), lentulo spiral (LS), Easy Clean (EC), and EndoActivator (EA) subgroups. Moreover, the distances of 5 mm and 2 mm from the apex were analyzed. The teeth were obturated with AH Plus and GuttaCore X3. Analyses were performed by scanning electron microscopy associated to cathodoluminescence. The percentage and maximum depth of sealer penetration were measured. Data were evaluated by three-way analysis of variance (ANOVA) and Games-Howell test (p<0.05). EA was superior to NT in percentage of sealer penetration. EC was significantly superior to EA (subgroup) for sealer penetration, and both improved the percentage of sealer penetration when compared to LS. Better sealer penetration was observed at the distance of 5 mm from the apex. Sealer penetration into the dentinal tubules was significantly improved by sonic irrigant activation.</p></div

A micro-CT evaluation of the performance of rotary and reciprocating single-file systems in shaping ability of curved root canals.

To compare the shaping ability of different single-file systems in the preparation of mesial curved canals of mandibular molars using micro-CT technology. Fifteen mesial roots of mandibular molars with two independent and curved canals (n = 30) were selected, scanned at a resolution of 26.7 μm anatomically matched, and distributed into three groups (n = 10), according to the preparation system: WaveOne 25.08, Reciproc 25.08, and OneShape 25.06. A final micro-CT scanning was performed, data sets were registered with their respective counterparts, and compared regarding the three-dimensional (volume, surface area, and structure model index - SMI) and two-dimensional (perimeter, area, roundness, major and minor diameters) parameters, as well as, canal transportation, using ANOVA and post hoc Tukey tests (α = 5%). Overall, no difference was observed between groups regarding area, perimeter, volume, surface area, and canal transportation (p > 0.05). Within group, no canal transportation was significantly higherobserved in the apical third (0.10 ± 0.05 mm) compared to coronal (0.08±0.040 mm) and middle (0.07 ± 0.03 mm) thirds (p < 0.05). Structure model index (SMI) was statistically higher after preparation with OneShape instrument (0.36 ± 0.26) compared to other systems (p < 0.05). Within the parameters of this study, similar shaping ability was observed in the preparation of mesial curved root canals of mandibular molars with Reciproc, OneShape and WaveOne systems.status: Published onlin