Reparo de perfurações na furca de dentes de cães, seladas com endomethasone com e sem barreiras de hidroxido e sulfato de calcio

Orientador: Luiz ValdrighiTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: A reparação de perfurações radiculares na região de furca de dentes, seladas imediatamente foi avaliada clínica, histológica e radiograficamente. Vinte e quatro dentes pré-molares inferiores, de cães adultos jovens, receberam perfurações experimentais na região de furca. Os materiais utilizados para a pesquisa foram: o Endomethasone, o cimento de hidróxido de cálcio e o sulfato de cálcio. O Endomethasone foi o material utilizado para o preenchimento do trajeto das perfurações, enquanto o cimento de hidróxido de cálcio e o sulfato de cálcio foram utilizados como anteparo, ou barreira para melhorar as condições de condensar o Endomethasone. Os dentes foram selados com resina composta fotopolimerizável precedida de condicionamento ácido e aplicação de adesivo dentinário. Após períodos experimentais, de 14 e 90 dias, os animais foram sacrificados e as estruturas anatomicas foram processadas para a análise histológica no microscópio óptico. A avaliação clínica mostrou que não houve envolvimento periodontal dos dentes analisados. Radiograftcamente, após 90 dias, não foram observadas perdas ósseas significativas. As avaliações histopatológicas mostraram que a colocação de uma barreira melhora as condições de condensação do material selador e tende a evitar sua extrusão e que não houve, em nenhum dos casos analisados, a completa reparação das perfurações com material calcificadoAbstract: The purpose of the present study was to evaluate the histological and radiological response to two. materials used as a matrix under a zinc oxide-eugenol cement used as a sealant in the repair of furcation perforations in experimental animals. After anesthesia, rootcanal treatment of canaIs with zinc oxide-eugenol cement, furcal perforations were made in 24 lower premolar (p3 and P4) teeth of mongrel dogs, with L.N. burs. The perforated teeth were random1y divided into 3 groups of 8 teeth: Group I - perforations sealed with Endomethasone; Group II - perforations sealed with Endomethasone after the placement of an internal matrix of calcium hydroxide; Group m - perforations sealed with Endomethasone after the placement of an internal matrix of calcium sulfate. Pulp chamber of all teeth were filled with composite resin after acid etching and application of dentinal adhesive. Animals were sacrificed after 14 and 90 days. The teeth and surrounding structures were processed for light microscopy. The conclusion of this study is that a placement of a barrier at the pulp chamber aspect of a furcation perforation did not result in superior healing, compared with the use of zinc oxide-eugenol cement alone and complete healing of furcation perforations with hard tissue was not observed.DoutoradoEndodontiaDoutor em Clínica Odontológic

Reparação de perfurações experimentais (trepanações) seladas com diferentes materiais obturadores de canais radiculares

Orientador: Luiz ValdrighiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: o presente trabalho se propôs a realizar, em dentes de cães, a análise histopatológica da reação dos tecidos periodontais de suporte, diante da realização de perfurações experimentais (trepanações), seladas com diferentes materiais. F oram utilizados os segundos, terceiros e quartos pré-molares inferiores de cães adultos jovens, num total de 48 dentes. As perfurações experimentais foram realizadas nas raizes. mesiais dos dentes e seladas com 3 materiais, divididos em 4 grupos: Grupo I - Endomethasone; Grupo 11 - Sealapex; Grupo li - Hidroxiapatita e Endomethasone; Grupo IV - Hidroxiapatita e Sealapex . As observações foram efetuadas nos tempos experimentais de 14 e 90 dias. Os resultados mostraram que, no periodo experimental de 14 dias, o quadro histopatológico era caracterizado por sinais de destruição do ligamento periodontal, pelo processo inflamatório predominantemente constituído de infiltrado inflamatório de grau médio, sem diferenças apreciáveis entre os grupos estudados. No período experimental de 90 dias, o quadro histopatológico predominante era de inflamação muito discreta ou ausente, com sinais de reparação, à exceção do grupo IV que, nesse período, apresentou uma persistência de inflamação crônica ao redor do material extruído no ligamento periodontal. Aos 90 dias, os melhores resultados foram alcançados nos grupos I e lI, nos quais não foi utilizada a hidroxiapatita como anteparo do material selador. Palavras-chave canal radicular - tratamento; cão como animal de laboratório; dentes - histopatologiaAbstract: The purpose of this study was to evaluate, in dog teeth, the periodontal support tissues reaction to lateral root perforations, sealed with different materials. Second, third and fourth mandibular premolars of adult-young dogs have been used in a total of 48 teeth. The experimental perforations were created in mesial roots of the teeth and sealed with three materials, shared in four diferent groups: Group I - perforations ~ealed with Endomethasone; Group 11 - perforations sealed with Sealapex; Group 111 - perforations sealed with Endomethasone, after the placement of an internal matrix of hydroxylapatite; Group IV - perforations sealed with Sealapex, after the placement of an internal matrix of hydroxylapatite; The animal were sacrified at the intervals of 14 and 90 days after the experimento The results have shown that in the period of 14 days, the histopathological board was characterized by the destruction signs of the periodontal ligament through an inflammatory process mostly constitued of a medium degree of cell infiltrate without differences among the groups. At 90 days the predominating board was a mild or even an absent inflammation with signs of reparation, less group IV which has shown a chronical inflammation around the material extruded into the periodontal ligament. The best results were reached in groups I and 11, at 90 days, in which hydroxylapatite was not used as a internal matrix. Key-words . Root canal therapy~ dog as laboratory animals~ teeth histopathologyMestradoEndodontiaMestre em Clínica Odontológic

Factors Associated with Post-Endodontic Treatment Pain Performed by Students in an Endodontic Graduate Program

Introduction: The aim of this study was to evaluate the possible associations between pre-established clinical variables and manifestation of postoperative pain after endodontic treatments performed by graduate students in endodontics, from June 2016 to December 2017. Methods and Materials: A total of 998 dental patient charts were included in the study. All the patients underwent the same clinical protocol. Possible associations between postoperative pain and clinical variables were investigated, including age, gender, type of tooth, type of treatment, pulpal diagnosis, periradicular diagnosis, instrumentation system used, number of sessions, previous symptom, procedural accident, and endodontic sealer extrusion. Patients were contacted by telephone 24 h and 7 days after treatment completion and were asked about the degree of postoperative pain they had experienced, using a four-level scoring system: 0, no pain; 1, mild pain (no medication was needed); 2, moderate pain (an analgesic or anti-inflammatory was needed); 3, severe pain. Fischer’s exact test, Pearson’s test, and logistic regression were used for the statistical analysis of the data. A significance level of 0.05 was used. Results: A total of 8.6% of the patients reported having experienced postoperative pain, 50% of which reported mild pain, 47.7%, moderate pain, and 2.3%, severe pain. The only variable significantly associated with postoperative endodontic pain was pre-endodontic treatment symptoms (Pearson’s test, P=0.0047). The logistic regression analysis indicated that the association between use of the Reciproc system and sealer extrusion posed a significant risk for postoperative endodontic pain. Conclusion: Based on this retrospective cohort study, the incidence of moderate and severe pain after endodontic treatment was low, and the only variable associated with a higher frequency of patients reporting postoperative endodontic pain was previous pain/symptoms. Therefore, in these cases, pain management methods such as the use of analgesics before treatment or immediately after treatment should be considered

Effects of Glide Path on the Centering Ability and Preparation Time of Two Reciprocating Instruments

Introduction: The aim of this in vitro study was to evaluate the effects of establishing glide path on the centering ability and preparation time of two single-file reciprocating systems in mesial root canals of mandibular molars. Methods and Materials: Sixty extracted mandibular molars with curvatures of 25-39 degrees and separate foramina for the mesiobuccal and mesiolingual canals, were divided into four groups (n=15); WaveOne+glide path; WaveOne; Reciproc+glide path and Reciproc. Non-patent canals were excluded and only one canal in each tooth was instrumented. A manual glide path was established in first and third groups with #10, 15 and 20 hand K-files. Preparation was performed with reciprocating in-and-out motion, with a 3-4 mm amplitude and slight apical pressure. Initial and final radiographs were taken to analyze the amount of dentin removed in the instrumented canals. The radiographs were superimposed with an image editing software and examined to assess discrepancies at 3-, 6- and 9-mm distances from the apex. The Kruskal-Wallis test was used for statistical analysis. The level of significance was set at 0.05. Results: Preparation in groups without glide paths was swifter than the other groups (P=0.001). However, no difference was observed regarding centering ability. Conclusion: Establishing a glide path increased the total instrumentation time for preparing curved canals with WaveOne and Reciproc instruments. Glide path had no influence on the centering ability of these systems.Keywords: Centering Ability; Glide Path; Reciproc; Root Canal Preparation; Single-File Instrumentation; WaveOn

Root Fracture Resistance of Maxillary Premolars Obturated with Three Root Canal Sealers after Passive Ultrasonic Irrigation: An in Vitro study

Introduction: Maxillary premolars, may be more susceptible to fracture due to their anatomy; especially when there is loss of tooth structure. Therefore, it is necessary to evaluate materials and techniques that may increase fracture resistance during and post root canal treatment. This in vitro study aimed to evaluate root fracture resistance of maxillary premolars when filled with three root canal sealers as well as whether this resistance would be increased by passive ultrasonic irrigation (PUI). Methods and Materials: Sixty-four maxillary premolars with two roots were randomly divided into one negative control group (intact canals; n=8), one positive control group (instrumented, unsealed canals; n=8), and six experimental groups (n=8), which were instrumented with ProTaper Next rotary system up to X2 file and subdivided according to final irrigation (with or without PUI) and type of sealer used (AH-Plus [AH], MTA Fillapex [MTA], or EndoSequence BC Sealer [ES]). The specimens were subjected to fracture strength test in a universal testing machine at a speed of 1 mm/min until fracture. The maximum force required to induce fracture was recorded (N).  Results: The lowest force required to cause root fracture was observed in the positive control group (310.48±54.08 N); this was significantly different from the other groups (P<0.05). There was no significant difference between experimental groups obturated with the same sealer, whether with or without PUI (AH with PUI: 558.80±87.12 N; AH without PUI: 508.75±97.55 N; MTA with PUI: 507.27±174.55 N; MTA without PUI: 516.69±96.56 N; ES with PUI: 526.76±143.97 N; ES without PUI: 628.40 ± 94.74 N) (P>0.05). There was also no significant difference between the experimental groups and the negative control group (P>0.05). Conclusions: In this in vitro study PUI did not increase the fracture resistance of maxillary premolars, while AH Plus, MTA Fillapex, EndoSequence sealers increased fracture resistance of instrumented root canals

Removal of Obturation Material from Root Canals Using a Combination of Reciprocal Instrumentation and Different Final Irrigation Techniques

Introduction: The predictability of successful non-surgical endodontic retreatment is directly related to it’s ability to completely cleanse and remove obturation material from the canal system. The purpose of this study was to evaluate the removal of gutta-percha from curved canals using three final irrigation methods: passive ultrasonic irrigation (PUI) with a 20/01 E1 insert (Irrisonic); XP-endo Finisher (XPF); and Easy Clean (EC). Methods and Materials: Forty mesial roots of mandibular molars with an angle of curvature between 10° and 20°, two canals, and independent foramina were cut into 16-mm sections. The canals were instrumented using the Reciproc system (R25) and filled with a #25 gutta-percha cone and AH-Plus sealer by the continuous-wave condensation technique. The roots were double-sealed with Coltosol and photopolymerizable resin and stored at 37°C and 100% humidity for 30 days. They were then randomized into 4 groups (n=10): control (C), PUI, XPF, and EC. All specimens were scanned using cone-beam computed tomography (CBCT), and fill volume data (in square pixels) were calculated before retreatment, after retreatment, and after final irrigation. The images were analyzed using Tps Dig software 2.32 by two blinded, calibrated examiners (intra-class correlation coefficient=0.9967). The results were analyzed in BioEstat 4.0. The nonparametric Kruskal-Wallis test with Dunn's post-hoc and Friedman comparison were applied. Significance was accepted at 5% (P<0.05). Results: None of the final irrigation protocols completely removed remnants of obturation material from the root canal systems (P>0.05). On comparative analysis with specimens divided into thirds, all methods were found to remove material equally, with no significant differences (P>0.05). Conclusion: Based on this in vitro study, the additional cleaning methods tested were equivalent to each other and did not lead to an improvement in the removal of residual obturation material

Influence of Passive Ultrasonic Irrigation of the Photosensitizer Used in Photodynamic Therapy on Microbial Reduction in the Root Canal System: An in Vitro Study

Introduction: The success of endodontic treatment is based on microbial reduction promoted by the interaction of chemical and mechanical procedures. Photodynamic therapy (PDT) is used as an adjunct to conventional treatment, with significant microbial reduction. This study aimed to evaluate the influence of passive ultrasonic irrigation (PUI) of the photosensitizer (PS) used in PDT on microbial reduction in the root canal system. Materials and Methods: Forty-five mesiobuccal root canals from extracted human mandibular molars that were inoculated with standard strains of Enterococcus faecalis, Candida albicans, and Streptococcus mutans for 21 days were selected. The root canals were prepared using the ProTaper Next system and randomly divided into 3 groups (n=15): 1) PDT: PDT alone; 2) PUI+PDT: PUI followed by PDT; and 3) PUI/PS+PDT: PUI of the PS followed by PDT. Microbiological samples were collected from the canals before and after using the protocols described above. The data were analyzed by analysis of variance (Tukey’s test) at a significance level of 5%. Results: Microbial counts before PDT, PUI+PDT, and PUI/PS+PDT did not differ significantly (P>0.05), showing methodological standardization in the microbial contamination of the root canal system. There was a significant reduction in microbial counts after PDT (61.05%), PUI+PDT (65.04%), and PUI/PS+PDT (68.58%) (P<0.01), but with no statistically significant difference between the three groups (P>0.05). Conclusion: Based on the present findings, it was concluded that the combination of PUI with PDT or PS activation did not influence microbial reduction achieved by PDT alone

Comparison of the effectiveness of the protaper system versus hand instrumentation in endodontic retreatment: a scanning electron microscopy study

Abstract Introduction: Several rotary systems have been evaluated for removal of endodontic filling materials from the canal. Moreover, studies focusing on the comparison of the effectiveness of rotary systems versus hand instrumentation have yielded mixed results in terms of the efficacy and amount of time required by each technique. Objective: To compare the effectiveness of a nickel-titanium rotary system and of hand instrumentation using stainless steel files and Gates-Glidden burs in the removal of gutta-percha from root canals, as well as the time required to complete the procedure by each method. Material and methods: Forty single-rooted teeth were prepared and obturated then divided in two groups, according to the method employed for removal of the gutta-percha: ProTaper Universal rotary retreatment system (rotary instrumentation) and stainless steel hand files with Gates-Glidden burs (hand instrumentation). The time required to remove gutta-percha by each method was recorded. Roots were then sectioned lengthwise and the apical, middle, and coronal thirds were analyzed by SEM under two magnifications: x400 an

The SIB Swiss Institute of Bioinformatics' resources: focus on curated databases

The SIB Swiss Institute of Bioinformatics (www.isb-sib.ch) provides world-class bioinformatics databases, software tools, services and training to the international life science community in academia and industry. These solutions allow life scientists to turn the exponentially growing amount of data into knowledge. Here, we provide an overview of SIB's resources and competence areas, with a strong focus on curated databases and SIB's most popular and widely used resources. In particular, SIB's Bioinformatics resource portal ExPASy features over 150 resources, including UniProtKB/Swiss-Prot, ENZYME, PROSITE, neXtProt, STRING, UniCarbKB, SugarBindDB, SwissRegulon, EPD, arrayMap, Bgee, SWISS-MODEL Repository, OMA, OrthoDB and other databases, which are briefly described in this article