Effectiveness of ProTaper Universal® and D-RaCe® retreatment files in the removal of root canal filling material: an in vitro study using digital subtraction radiography

Aim: To compare the effectiveness of the ProTaper Universal® Retreatment system, the D-Race® NiTi system and Hedströem files for removal of filling material from curved root canals. Methodology: A total of 39 first mandibular molars were selected and their mesiobuccal (MB) canals were used for the study. Teeth were assigned to one of three identical groups (n = 13 per group) according to removal technique: G1 – ProTaper Universal® Retreatment (D1, D2, D3); G2 – D-RaCe® (DR1, DR2); or G3 – Hedströem files (35, 30, 25, 20). In all groups, supplementary files were used for re-preparation. Digital subtraction radiography images were produced by superimposing the first radiograph, taken after filling the canal, over the second, taking after removal of the filling, in buccolingual (BL) and mesiodistal (MD) projections. Quantitative data were analyzed using intraclass correlation coefficients and the Kruskal-Wallis and Friedman non-parametric tests (p ≤ 0.05). Results: Comparison of groups detected no differences in filling removal between teeth in the ProTaper Universal® Retreatment, D-RaCe® or Hedströem file groups for the cervical or mid thirds (for either MD or BL projections). In the apical third (MD projection), ProTaper Universal® Retreatment produced the best results; and Hedströem files exhibited the worst results (MD projection). Intra-group comparisons showed that the cervical third was the cleanest and the apical third was the least well-cleaned, for the ProTaper Universal® Retreatment and D-RaCe® groups (MD projection), while less filling material was removed using Hedströem when the canals approached the apical third (MD and BL projections).Conclusions: Our findings indicate that the ProTaper Universal® Retreatment system is the best choice for endodontic filling material removal, combined with supplementary instrumentation to achieve better results in the apical third

ENDODONTIC RETREATMENT: ANALYSIS OF THREE SPECIALISTS’ RETREATMENT RATES

Retratamento endodôntico é uma intervenção clínica destinada para corrigir erros que ocorreram em um tratamento realizado anteriormente. Existem várias causas de falhas. As variações anatômicas entre canais radiculares e as dificuldades de obtenção de desinfecção microbiana são relatados como duas das principais causas. No entanto, nos consultórios odontológicos de ambos os clínicos gerais e especialistas, é muito comum que as causas das indicações para retratamento endodôntico são falhas técnicas devido ao tratamento mal executado. Em vista disso, o objetivo deste estudo é analisar os registros de três especialistas em Endodontia e analisar as causas para o encaminhamento de seus pacientes retratamento endodôntico. Exame de 24,553 tratamentos realizados ao longo de períodos que variam revelou que os casos de retratamento foram responsáveis ​​por uma proporção considerável do trabalho de rotina realizados por esses especialistas, em uma média de 23% dos casos. A maioria das indicações de retratamento foram devido a falha técnica do tratamento inicial, em combinação com fatores microbianas causadas por contaminação de restaurações coronal e preparação endodôntico mal executado e enchimento

Apicificação de incisivos centrais superiores usando hidróxido de cálcio: relato de caso

When there is the pulp necrosis in permanent teeth with open root apex, there is the need to induce the root development aiming to create a barrier of mineralized tissue at the apical third, making it easy, subsequently, definitive filling of the root canal. This technique is called apexification. The following work aimed to describe a successful treatment with calcium hydroxide at the 11 and 21 teeth, which suffered pulp necrosis after a trauma.Quando ocorre a necrose pulpar em dentes permanentes com ápice incompleto, há necessidade de induzir o desenvolvimento radicular com a finalidade de criar uma barreira de tecido mineralizado no terço apical facilitando posteriormente a obturação definitiva do canal radicular. Esta técnica é denominada de apicificação. O objetivo deste trabalho foi descrever um tratamento bem sucedido de apicificação nos dentes 11 e 21 que sofreram necrose pulpar após a ocorrência de um trauma

Cytotoxicity and Bioactivity of Calcium Silicate-based Cements in a Culture of Stem Cells from the Apical Papilla

Introduction: The present in vitro study evaluated the cytotoxicity and bioactivity of commonly-used calcium silicate-based cements in a culture of stem cells from the apical papilla (SCAPs). Materials and Methods: NeoMTA Plus (Avalon Biomed), BiodentineTM (Septodont) and MTA HP Repair (Angelus) cements were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and sulphorhodamine-B (SRB) viability assays. Cells were seeded (1*104 cells mL-1) in 96-well plates and exposed to 1:4 diluted extract in 24 h and 72 h. For the analysis of bioactivity, alkaline phosphatase (ALP) enzyme activity and Alizarin Red S (AZR) were assessed after 24 h of cell culture in 12-well plates (1*104 cells mL-1), where cells were exposed to 1:4 diluted extract on days 1 and 7. Minimum Essential Eagle’s Medium alpha modification was used as control. ANOVA and Tukey’s post hoc test were used to compare the different cements at each experimental time point. Results: No significant differences were found between the cements and the control specimens on MTT at 24h and 72 h (P>0.05); however, the calcium silicate-based cement materials showed higher cell viability compared to the control group (P<0.05). In the 24-h SRB, NeoMTA Plus showed lower cell viability than BiodentineTM and MTA HP Repair (P<0.05), with all groups similar to the control group (P>0.05). Compared to 24-h results, only NeoMTA Plus presented increased cell viability at 72h (P<0.05). ALP activity was similar across the materials at 1day (P>0.05). ALP activity was higher for BiodentineTM when compared to NeoMTA Plus (P<0.05), nevertheless, it was similar to MTA HP Repair and control groups (P>0.05) at 7days. At 1- and 7-day periods ofAZR assay, BiodentineTM presented higher levels of mineralized nodule formation (P<0.05). Conclusion: All evaluated calcium silicate-based cements demonstrated cell viability and bioactivity, suggesting that these (bio)materials may be indicated for use in regenerative dentine-pulp complex procedures

Histopathological analysis of corticosteroid-antibiotic preparation and propolis paste formulation as intracanal medication after pulpectomy: an in vivo study

Intracanal medication in pulpectomy therapy is used between appointments with the objective of reducing pain and inflammatory processes in pulp and periapical tissues. Propolis has been known as a natural antibiotic and has been subject of medical and dental research due to its therapeutic properties such as antibiotic, analgesic and anti-inflammatory effects. OBJECTIVE: The aim was to carry out an in vivo evaluation of the periapical tissue response to propolis paste when used as an intracanal medication in the teeth of dogs after pulpectomy. MATERIAL AND METHODS: 72 dog's incisors were selected for the experiment. After biomechanical preparation the root canal was filled with a corticosteroid-antibiotic preparation, experimental propolis paste, non-medicament (negative control) or non-pulpectomy at all (positive control). The medications were left inside the root canal for 7, 14 or 28 days. At the end of the experimental period histological sections were prepared and all laboratories processes for Harris hematoxylin and eosin staining was proceeded followed by the analysis using an optical microscope. Sections were classified according to a score representing the inflammatory events observed: the presence of polymorphonuclear neutrophils, polymorphonuclear eosinophils, lymphocytes and plasma cells, macrophages and/or giant cells, fibrous condensation and abscesses. RESULTS: There were statistically significant differences between the tissue reactions caused by the two substances being tested, after different experimental periods, with the periapical tissue that was in contact with propolis paste exhibiting fewer inflammatory reactions in comparison to corticosteroid-antibiotic preparation. CONCLUSIONS: The low tissue responses from propolis paste suggest that this material could be considered as an option for root canal medication after pulpectomy

Comparative analyses of the obtaiment of odontometric with radiographics methods (long and short cone) and electrical methods (Endometer)

Os autores analisaram in vivo comparativamente a obtenção de odontometria com métodos radiográficos (Técnica do paralelismo e Técnica da bissetriz) e método elétrico (Endometer), em 90 dentes unirradiculares com polpas vivas, indicados para extração por motivos diversos. Quando da obtenção de odontometria com a técnica do paralelismo, observaram-se os melhores resultados, seguido pelo método elétrico (Endometer) e, por último, da técnica da bissetriz.The aim of this study was to compare the determination of the tooth lenght of two radiographic methods (the Paralellism Technique and the Bissector Technique and an electric method (The Endometer Technique) in 90 vital anterior teeth that had to be extracted for different reasons

Effect of dental bleaching on pulp oxygen saturation in maxillary central incisors - a randomized clinical trial

Objective: To assess pulp oxygen saturation levels (SaO2) in maxillary central incisors after dental bleaching. Materials and Methods: 80 participants (160 teeth) were randomly allocated to four groups: G1 In-office bleaching with two applications of 35% hydrogen peroxide (HP) (20 minutes), followed by at-home bleaching with 10% carbamide peroxide (CP) (2 hours/day for 16 days); G2 - Same protocol as G1, plus desensitizing toothpaste; G3 - Inoffice bleaching with 35% HP and one application of placebo gel (20 minutes), followed by at-home bleaching with 10% CP (2 hours/day for 16 days); and G4 - Same protocol as G3, plus desensitizing toothpaste. Pulp SaO2 levels were measured before (T0) and immediately after (T1) in-office bleaching; on the 5th (T2), 8th (T3), 12th (T4), and 16th days of at-home bleaching (T5); and on the 7th (T6) and 30th (T7) days. Mean (SD) pulp SaO2 levels were compared within groups by generalized estimating equations (GEE) and Student’s t-test (P<0.05). Results: Mean pulp SaO2 at T0 was 84.29% in G1, 84.38% in G2, 84.79% in G3, and 85.83% in G4. At T1, these values decreased to 81.96%, 82.06%, 82.19%, and 81.15% in G1, G2, G3, and G4 respectively, with significant difference in G4 (P<0.05). During home bleaching, pulp SaO2 levels varied in all groups, with 86.55%, 86.60%, 85.71%, and 87.15% means at T7 for G1, G2, G3, and G4, respectively; G2 presented significant difference (P<0.05). Conclusions: Pulp SaO2 level in maxillary central incisors was similar at baseline, reducing immediately after in-office bleaching, regardless of using desensitizing toothpaste and increasing at 30 days after dental bleaching