Carlos Alexandre Bier | UFSM - Universidade Federal de Santa Maria (original) (raw)

Papers by Carlos Alexandre Bier

RGO (Porto …, 2005

Base de dados : LILACS. Pesquisa : 436243 [Identificador único]. Referências encontradas : 1 [ref... more Base de dados : LILACS. Pesquisa : 436243 [Identificador único]. Referências encontradas : 1 [refinar]. Mostrando: 1 .. 1 no formato [Detalhado]. página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. Carvalho, Maria Gabriela Pereira de. ...

Odontol Clin Cient, Apr 1, 2004

Objective: To evaluate the effect of root obturation techniques on root fracture resistance and t... more Objective: To evaluate the effect of root obturation techniques on root fracture resistance and to analyze, by finite elements analysis, the expansion of the endodontic sealer in two different obturation techniques. Method: Thirty single-rooted human teeth were instrumented using rotary files, at a standardized working length (14 mm). The specimens were embedded in a plastic cylinder using acrylic resin, and allocated into 3 groups (n=10): G(lateral) - lateral condensation; G(single-cone) – single cone; G(tagger) - Tagger’s hybrid technique. The root canals were prepared to a length of 11mm with the #3 preparation bur of a tapered glass fiber-reinforced composite post system. All roots received glass fiber posts, which were adhesively cemented and the core built was performed with composite resin. All groups were submitted to fracture resistance test (1mm/min, 45º). Data were submitted to 1-way ANOVA and post-hoc Tukey test. The FEA was performed by using two models: one simulated t...

$Research paper thumbnail of Influence of root canal treatment techniques on fracture resistance$

Objective: To evaluate the effect of root canal treatment on fracture strength of roots restored ... more Objective: To evaluate the effect of root canal treatment on fracture strength of roots restored with glass fiber post. Method: Experimental design: 2 factors- instrumentation in 2 levels (hand instrumentation, rotary instrumentation) and obturation in 2 levels (lateral condensation, no compactation) (factorial 2x2 = 4 groups). Thus, 68 single-rooted human permanent teeth (pre molars and canines) had their coronal portion removed (root = 15 mm length) and the roots that had apical diameter corresponding to a size 25 K file were selected. The roots were randomly divided into 4 groups, according to the instrumentation and filling techniques (n=17): G1 - hand instrumentation + lateral condensation; G2 - rotary instrumentation + lateral condensation; G3 - hand instrumentation + no compactation; G4 - rotary instrumentation + no compactation. All the specimens were embedded in acrylic resin followed by the periodontal ligament simulation. After the obturation procedures, all root canals w...

Objective: to assess and compare the influence of the root canal treatment with and without passi... more Objective: to assess and compare the influence of the root canal treatment with and without passive ultrasonic irrigation with 17% ethylenediaminetetraacetic acid (EDTA) and 10% citric acid on the sealing of pre-molars root canal fillings. Method: a hundred and fifteen single-rooted, human mandibular pre-molars, with oval canal, were selected. The teeth were prepared with rotatory instrumentation and irrigated according to the following protocols (n=23): G1, 17% EDTA + US; G2, 17% EDTA; G3, 10% citric acid + US; G4, 10% citric acid and a control group, 2,5%.sodium hypochlorite (NaOCl). The specimens were filled according to the no compaction technique and then inserted to a device for measuring the glucose leakage. Leakage was assessed through a Glucose Kit in a spectrophotometer at 7, 14, 21 and 30 days. Result: Kruskal-Wallis test results showed less leakage on passive ultrasonic irrigation groups, with both test solutions (p<0,05). Mann-Whitney analysis showed that teeth treat...

Journal of Applied Oral Science, 2003

This in vivo study analyzed the sealing ability of two adhesives in post spaces, cyanoacrylate (S... more This in vivo study analyzed the sealing ability of two adhesives in post spaces, cyanoacrylate (Super Bonder® - Henkel Loctite Adesivos Ltda., Itapevi, SP, Brazil) and ScotchbondTM Multi-Purpose (3M Dental Products, St. Paul, MN, USA), testing the hypothesis that their use would result in a decreased leakage through the remaining filling material. Forty extracted premolars (80 root canals) of dogs were used. The root canals were cleaned, shaped and filled by the lateral condensation technique using Sealer 26TM. The post space was created removing two thirds of the filling material within the root canal. The canals were randomly divided in three groups, which were treated as follows: Group A received the ScotchbondTM Multi-Purpose adhesive system; for Group B the cyanoacrylate adhesive, Super BonderTM, was employed; and no adhesive was applied into the post space for Group C (control group). A glass ionomer provisional restoration was placed allowing the sealer to set for 72 hours. T...

International Endodontic Journal, 2009

Aim To evaluate ex vivo the incidence of defects in root dentine before and after root canal prep... more Aim To evaluate ex vivo the incidence of defects in root dentine before and after root canal preparation and filling. Methodology Eighty extracted mandibular premolars were divided equally in four groups. Group 1 was left unprepared. All other root canals were prepared using Gates Glidden drills and System GT files up to size-40, 0.06 taper at the working length. Group 2 was not filled while the canals of the other groups were filled with gutta-percha and AH26, either with a master cone and passive insertion of secondary gutta percha points (group 3) or lateral compaction (group 4). Roots were then sectioned horizontally 3, 6, and 9 mm from the apex and observed under a microscope. The presence of dentinal defects (fractures, craze lines or incomplete cracks) was noted and the differences between the groups were analysed with the Fisher's exact test. Results No defects were observed in the roots with unprepared canals. The overall difference between the groups was significant (P < 0.05). Canal preparation alone created significantly more defects than unprepared canals (P < 0.05). The total number of defects after lateral compaction was significantly larger than after noncompaction canal filling. Conclusion Root canal preparation and filling of extracted teeth created dentine defects such as fractures, craze lines and incomplete cracks.

Australian Endodontic Journal, 2007

The goal of this study was to evaluate the thermoplasticity of conventional and thermoplastic gut... more The goal of this study was to evaluate the thermoplasticity of conventional and thermoplastic gutta-percha and Resilon ® , a polyester polymer-based material. Specimens with standardised dimensions were made from the following materials: conventional and thermoplastic gutta-percha (Dentsply), conventional and thermoplastic gutta-percha (Endopoints) and Resilon ®. After 24 h, the specimens were placed in water at 70°C for 60 s, and thereafter positioned between two glass slabs. Each set was compressed by a 5-kg weight. Digital images of the specimens before and after compression were obtained and analysed. The thermoplasticity of each material was confirmed by the difference between final and initial areas of each sample. The data were analysed statistically by ANOVA and Tukey's test at a 5% significance level. Resilon ® had the highest thermoplasticity means (P < 0.05). Among the gutta-percha cones, Endopoints TP (thermoplastic) presented the highest thermoplasticity means and differed significantly from the other commercial brands (P < 0.05). Resilon ® had good thermoplasticity, endorsing its use as a thermoplastic root canal filling material.

Revista Odonto Ciência, 2011

Purpose: To simulate soft and hard tissues to assess radiopacity of three root canal sealers (End... more Purpose: To simulate soft and hard tissues to assess radiopacity of three root canal sealers (Endofill, AH Plus and Sealer 26). Methods: Five circular specimens (10x1 mm) were made and three experimental conditions were created. Situation #1: an aluminum step wedge allowed specimen being submitted to three digital radiographs. Situation #2: a retromolar mandibular segment containing the specimen was positioned between the digital sensor and X-ray machine. Situation #3: a soft tissue simulating material (utility wax-30 mm) was associated with the mandibular segment. Mean gray values were measured using ImageTool 3.0 software. Two-way ANOVA and Tukey's test (α=0.05) was performed. Results: Radiopacity increased when bone tissue was used (P<0.05), except for AH Plus. Situation #3 provided greater radiopacity (P<0.05). Radiopacity between most and least sealers decreased 44% when Situation #1 and #3 were compared. Conclusion: Simulated soft and hard tissues influenced the radiopacity of root canal sealers.

Methods: Twenty eight roots of freshly extracted teeth were gauged with a size 5 Largo drill. Wit... more Methods: Twenty eight roots of freshly extracted teeth were gauged with a size 5 Largo drill. With a cutting machine slices of 2 mm were prepared, rinsed with 5.25% NaOCl and a final rinse with 17% EDTA, dried and filled with one of the sealers. After setting their bond strength was measured in a mechanical testing machine. The data were statistically analyzed by using a One Way ANOVA and post hoc Tukey test.

Investigación Clínica, 2021

The aim of this study was to compare the influence of a final rinse with and without passive ultr... more The aim of this study was to compare the influence of a final rinse with and without passive ultrasonic irrigation (PUI), using 17% ethylenediaminetetraacetic acid (EDTA) or 10% citric acid (CA), with 2.5% sodium hypochlorite (NaOCl) with PUI, on the sealing ability of root canal fillings. Root canal instrumentation was performed in single-rooted premolars using NaOCl as the irrigant. Subsequently, the roots were randomly allocated into four experimental groups (n=23): EDTA+PUI, EDTA, CA+PUI, CA and control group: NaOCl+PUI. The specimens were root-filled using gutta-percha with a resin-based sealer and inserted into a device to measure glucose leakage at 7 and 30 days. Kruskal-Wallis and Mann- Whitney tests were used to evaluate the differences between the solutions and with or without PUI. Friedman’s ANOVA was used to compare time points (P<0.05). PUI groups showed lower infiltration values (EDTA+PUI 0.74±0.77 and CA+PUI 5.32±1.45) when compared to the groups on which PUI was n...

Journal of applied oral science : revista FOB, Jan 21, 2015

Objectives The aim of this study was to evaluate the volume of remaining filling material after p... more Objectives The aim of this study was to evaluate the volume of remaining filling material after passive ultrasonic irrigation (PUI) of sodium hypochlorite (NaOCl) and orange oil in mesial canals of mandibular molars, with and without isthmus. Material and Methods Thirty mesial roots of mandibular molars were divided according to the presence or absence of isthmus. Canals were prepared and filled (Micro-CT #1). Filling was removed using rotary instruments, and specimens were sub-divided into three groups according to the irrigation procedures: Conventional - conventional irrigation with NaOCl, PUI/NaOCl - PUI of NaOCl (three activations, 20 seconds each), and PUI/orange oil - PUI of orange oil (Micro-CT#2). Specimens were enlarged using the X2 and X3 ProTaper Next instruments and submitted to the same irrigation protocols (Micro-CT #3). Results No differences were found between the experimental groups in each stage of assessment (P>0.05). The volume of residual filling material wa...

$Research paper thumbnail of Effect of root canal preparation, type of endodontic post and mechanical cycling on root fracture strength$

Journal of Applied Oral Science, 2014

O bjective: To evaluate the impact of the type of root canal preparation, intraradicular post and... more O bjective: To evaluate the impact of the type of root canal preparation, intraradicular post and mechanical cycling on the fracture strength of roots. Material and Methods: eighty human single rooted teeth were divided into 8 groups according to the instruments used for root canal preparation (manual or rotary instruments), the type of intraradicular post (fiber posts-FRC and cast post and core-CPC) and the use of mechanical cycling (MC) as follows: Manual and FRC; Manual, FRC and MC; Manual and CPC; Manual, CPC and MC; Rotary and FRC; Rotary, FRC and MC; Rotary and CPC; Rotary, CPC and MC. The filling was performed by lateral compactation. All root canals were prepared for a post with a 10 mm length, using the custom #2 bur of the glass fiber post system. For mechanical cycling, the protocol was applied as follows: an angle of incidence of 45°, 37°C, 88 N, 4 Hz, 2 million pulses. All groups were submitted to fracture strength test in a 45° device with 1 mm/ min cross-head speed until failure occurred. Results: The 3-way ANOVA showed that the root canal preparation strategy (p<0.03) and post type (p<0.0001) affected the fracture strength results, while mechanical cycling (p=0.29) did not. Conclusion: The root canal preparation strategy only influenced the root fracture strength when restoring with a fiber post and mechanical cycling, so it does not seem to be an important factor in this scenario.

Iranian Endodontic Journal, 2017

Introduction: The aim of this study was to evaluate the incidence of dentinal defects and vertica... more Introduction: The aim of this study was to evaluate the incidence of dentinal defects and vertical root fractures (VRFs) after endodontic retreatment and mechanical cycling (MC). Methods and Materials: Two hundred mandibular premolars were selected. Forty teeth were left unprepared (control group). The remaining 160 root canals were prepared with ProTaper instruments and filled by using two different techniques [eighty with lateral compaction (LC) and eighty with single-cone (SC)]. Forty canals from each group (LC and SC) received no further treatment. The remaining eighty teeth were divided into two groups (LCR and SCR) (n=40) in order to undergo the removal of the root filling, re-preparation and refilling with lateral compaction and single-cone, respectively. All of the teeth were subjected to MC (1000000 cycles, 130 N, 2.2 Hz and 37°C). The roots were sectioned at 3, 6 and 9 mm from the apex and observed under 20× magnification. The defects were classified as: no defect, VRF and...

Brazilian Dental Journal, 2013

The aims of this study were to evaluate the effect of root canal filling techniques on root fract... more The aims of this study were to evaluate the effect of root canal filling techniques on root fracture resistance and to analyze, by finite element analysis (FEA), the expansion of the endodontic sealer in two different root canal techniques. Thirty single-rooted human teeth were instrumented with rotary files to a standardized working length of 14 mm. The specimens were embedded in acrylic resin using plastic cylinders as molds, and allocated into 3 groups (n=10): G(lateral) - lateral condensation; G(single-cone) - single cone; G(tagger) - Tagger's hybrid technique. The root canals were prepared to a length of 11 mm with the #3 preparation bur of a tapered glass fiber-reinforced composite post system. All roots received glass fiber posts, which were adhesively cemented and a composite resin core was built. All groups were subjected to a fracture strength test (1 mm/min, 45°). Data were analyzed statistically by one-way ANOVA with a significance level of 5%. FEA was performed usin...

Revista de Odontologia da UNESP, 2016

Introduction The aim of endodontic retreatment is to remove the previous root filling materials c... more Introduction The aim of endodontic retreatment is to remove the previous root filling materials completely to allow for the subsequent steps of cleaning, canal shaping and filling replacement. Objective To evaluate the efficacy of passive ultrasonic irrigation (PUI) in the removal of residual root filling material after removing the bulk of the root filling with nickel-titanium rotary instruments. Material and method Eighteen mesial isthmus-containing roots of human mandibular molars were prepared and filled. The root canal filling was removed with the ProTaper Retreatment system and K-files. The specimens were randomized into 2 groups (n = 9), both irrigated with 2.5% NaOCl and 17% EDTA. In the conventional group, an irrigation syringe was used. In the PUI group, the PUI technique was used. The roots were sectioned longitudinally and evaluated under stereomicroscopy. Student’s t test was used to compare groups and the general linear model was used to compare the apical, cervical, a...

Aim: The aim of this study was to assess the thermoplasticity of materials used in root canal fil... more Aim: The aim of this study was to assess the thermoplasticity of materials used in root canal filling. Methods: Specimens with standardized dimensions were fabricated using Tanari, Roeko and Activ Point gutta-percha cones, as well as Microseal and TC gutta-percha. After 24 hours, the specimens were placed in water at 70 ºC for 60 seconds and positioned between two glass slabs. Each set was compressed by a 5 kg weight. Digital images of the specimens before and after compression were obtained and analyzed. The thermoplasticity was evaluated based on the difference between the final and initial areas. Data were statistically analyzed using ANOVA and Tukey's tests at a 5% significance level. Results: TC and Microseal gutta-percha presented the highest thermoplasticity (p < 0.05). Among the gutta-percha cones, Tanari and Roeko presented the highest thermoplasticity and differed when compared to Activ Point (p < 0.05). Conclusions: The results of the present study showed that TC and Microseal gutta-percha filling systems present better thermoplastic properties.

Journal of …, 2010

This ex vivo study used cone beam computed tomography to evaluate the amount of dentin removal fr... more This ex vivo study used cone beam computed tomography to evaluate the amount of dentin removal from the distal wall of the mesial canal of human mandibular first molars caused by 4 instruments used to flare the cervical third. ... Thirty-two mesial roots were divided into 4 groups ...

Influência dos agentes clareadores na microdureza de resina composta nanoparticulada ORIGINAL | O... more Influência dos agentes clareadores na microdureza de resina composta nanoparticulada ORIGINAL | ORIGINAL RESUMO Objetivo: Avaliar o efeito dos agentes clareadores na microdureza de uma resina composta nanoparticulada. Métodos: Vinte e oito corpos de prova cilíndricos (8 x 1mm) de resina Filtek TM Supreme XT (3M ESPE, Sumaré, Brasil) foram preparados e divididos em 5 Grupos. A microdureza Vickers inicial foi mensurada (carga de 50 gramas força por 30 segundos) na superfície de topo dos corpos de prova. Os grupos foram tratados e divididos da seguinte maneira: G1) saliva artificial (21 dias -controle); G2) gel de peróxido de hidrogênio 7% aplicado por 4h/dia, durante 14 dias; G3) peróxido de carbamida 10% por 4h/dia, durante 14 dias: G4) gel de peróxido de hidrogênio 35% aplicado em três sessões de 30 minutos cada, com intervalo entre sessões de uma semana (21 dias); e G5) peróxido de carbamida a 35%, três sessões de 30 minutos cada, com intervalo entre sessões de uma semana (21 dias). As superfícies de topo dos corpos de prova receberam os tratamentos e foram submetidas ao teste de microdureza Vickers. Resultados: Os resultados obtidos foram submetidos à Análise de Variância a um critério fixo, com nível de significância p=0,05. Não foram observadas diferenças significativas entre os tratamentos testados (p=0,42) quando comparados com G1. Diferenças significativas (Teste Tukey) foram encontradas quando comparados os valores de microdureza inicial com os valores após os tratamentos experimentais (p<0,01). Conclusão: A aplicação dos agentes clareadores não alterou a microdureza das resinas compostas. Portanto não há necessidade de troca das restaurações após o clareamento. Termos de indexação: clareamento de dente; resinas compostas; dureza. ABSTRACT Objective: To assess the effect of bleaching agents on the microhardness of nanoparticle resin composite. Methods: Twenty-eight cylindrical test specimens (8x1mm) of Filtek TM Supreme XT resin (3M/ESPE) were prepared and divided into 5 groups. The initial Vickers microhardness was measured (load of 50 grams force for 30 seconds) on the top surface of the test specimens. The groups were treated and divided as follows: G1 -artificial saliva (21 days -control); G2 -7% hydrogen peroxide gel applied for 4h/day, for 14 days; G3 -10% carbamide peroxide for 4h/day, for 14 days: G4 -35% hydrogen peroxide gel applied in three sessions of 30 minutes each, with an interval of one week (21 days) between the sessions; G5 -35% carbamide peroxide, three sessions of 30 minutes each, with an interval of one week (21 days) between the sessions. The top surfaces of the test specimens received treatment and were submitted to the Vickers microhardness test.

Journal of Endodontics, 2009

The purpose of this study was to compare the incidence of dentinal defects (fractures and craze l... more The purpose of this study was to compare the incidence of dentinal defects (fractures and craze lines) after canal preparation with different nickel-titanium rotary files. Two hundred sixty mandibular premolars were selected. Forty teeth were left unprepared (n ϭ 40). The other teeth were prepared either with manual Flexofiles (n ϭ 20) or with different rotary files systems: ProTaper (Dentsply-Maillefer, Ballaigues, Switzerland), ProFile (Dentsply-Maillefer), SystemGT (Dentsply-Maillefer), or S-ApeX (FKG Dentaire, La Chaux-de-Fonds, Switzerland) (n ϭ 50 each). Roots were then sectioned 3, 6, and 9 mm from the apex and observed under a microscope. The presence of dentinal defects was noted. There was a significant difference in the appearance of defects between the groups (p Ͻ 0.05). No defects were found in the unprepared roots and those prepared with hand files and S-ApeX. ProTaper, ProFile, and GT preparations resulted in dentinal defects in 16%, 8%, and 4% of teeth, respectively. Some endodontic preparation methods might damage the root and induce dentinal defects. (J Endod 2009;35:236 -238)