Análise comparativa da ação antimicrobiana dos cimentos endodônticos Acroseal, Sealapex e AH plus pós presa em biofilme de enterococcus faecalis

Pós-graduação em Ciência Odontólogica - FOA

Incomplete vertical root fracture associated with lateral compaction technique: a microscopic analysis

Objective: This study evaluated the effects of root canal obturation employing lateral compaction technique and spreader load of 1.5 kg on the incidence of complete (CVRF) or incomplete vertical root fractures (IVRF). Material and Methods: Twenty-seven distal roots of extracted human mandibular molars were used. All root canals were prepared by biomechanical step-back technique and obturated by lateral compaction technique. The prepared roots were distributed into two groups: G1- experimental (n = 17) and G2- control (n = 10). During obturation, load of 1.5 kg was applied to a size # 30 finger spreader. Pre- and post-obturation images of the coronal portion of the roots were captured by inverted digital microscopy and analyzed by one trained examiner. Data were evaluated by Fisher’s test (p < 0.05) using GrapH Pad Prism 5.0. Results: No roots exhibited CVRF. All fractures observed before and after obturation were IVRF or “other defects”. In G2 (control group), there was no increase of IVRF number. Interestingly, G1 presented an increase in the IVRF number to 70.59% in the 12 teeth out of 17 teeth studied. The statistical analysis showed that the mean of IVRF increased significantly in G1 when compared to G2 (p < 0.05). Conclusion: The application of a 1.5 kg spreader load during lateral compaction technique does not produce complete vertical root fractures, but may produce incomplete fractures or “other defects”.

Aspectos atuais do tratamento da infecção endodôntica

Endodontics is a science that embodies etiology, diagnosis, prevention, and treatment of apical periodontitis and its repercussion in the organism. Technological resources in diagnosis and root canal negotiation, and new strategies , associated to mainly cleaning and eliminating the infection of the root canal system, shaping, and filling the endodontic space, according to biological bases, will allow us to reach higher standards of post-treatment success.

Influência da agulha irrigadora e da dilatação do canal radicular na eficácia da irrigação endodôntica

Introduction: The irrigation of root canals aims to their cleaning and disinfection, improving endodontic treatment success. Objective: To investigate the influence of the diameter and type of irrigation needle and the root canal enlargement on the mechanical efficacy of endodontic irrigation. Material and methods: Twelve human single-rooted mandibular incisors were used. During some instrumentation stages (enlargement by #20, #30, and #40 K file), root canals were filled with radiographic contrast solution mixed to propyleneglycol and zinc oxide. Needles with different diameters and designs were employed: G1 – 23G and lateral opening; G2 – 22G and apical opening; G3 – 30G and lateral opening; G4 – 30G and apical opening. The needles were inserted up to resistance, with 1 mm step-back to avoid root canal obliteration. The irrigation was performed with 2 mL of distilled water. Before and after irrigation/aspiration, teeth were radiographed at bucco-lingual and mesiodistal direction, using a digital radiographic system. Then, root canal areas, before (filled by contrast solution) and after irrigation (remnant of contrast solution), were submitted to image subtraction with Adobe Photoshop CS4 software. Subsequently, the areas were measured by Image Tool 3.0 software, allowing the obtaining of the cleaning percentage for each modality. Data were analysed by using Anova and Tukey’s test. The level of significance was set at P < 0.05. Results: For all root canal enlargements, 30G needles (G3 e G4) presented a better cleaning efficacy. In all groups, higher cleaning efficacy percentage was observed at #30 and #40 K file enlargement. Conclusion: Regardless their design, thinner needles were more effective; a better cleaning efficacy occurred in more enlarged root canals.

Resolução por retratamento não cirúrgico de dente com lesão periapical: relato de caso clínico

The development and maintenance of periapical lesion occurs as a result of bacterial infection of the root canal system. Faced with the failure of endodontic treatment, retreatment is the first option with great potential for success, when performed with proper disinfection of the root canal system. Case report: Patient aged 39 years needing dental care show at clinical examination moderate gingival bleeding in the region of tooth 22 and the presence of radiographic periapical bone rarefaction due to unsatisfactory endodontic treatment. It was indicated the endodontic retreatment. We performed procedures to remove the filling material, root canal preparation using manual and mechanical techniques and completion with the use of root canal medication based on calcium hydroxide. After root canal filling, clinical and radiographic success were demonstrated for the case. Conclusion: We conclude that the non-surgical retreatment with disinfection and proper use of medication to the base of calcium hydroxide promoted success after outcome monitoring for 2 years and 8 months (AU)

Portland cement use in dental root perforations: a long term followup

Root canal and furcal perforations are causes of endodontic therapy failure and different materials that stimulate tissue mineralization have been proposed for perforation treatment. In the first case, a patient presented tooth 46 with unsatisfactory endodontic treatment and a periapical radiographic lesion. A radiolucent area compatible with a perforating internal resorption cavity was found in the mesial root. The granulation tissue was removed, and root canals were prepared. The intracanal medication was composed of calcium hydroxide and the perforation cavity was filled with Portland cement. The 11-year followup showed radiographic repair of the tissue adjacent to the perforation and absence of clinical signs and symptoms or periapical lesion. In the second case, a patient presented with edema on the buccal surface of tooth 46. The examination showed a radiolucent area in the furcation region compatible with an iatrogenic perforation cavity. The mesial root canals were calcified, and only the distal root canal was prepared. The cavity was filled with a calcium hydroxide-based paste and the distal root canal was obturated. In sequence, the perforation cavity was filled with Portland cement. The 9-year followup showed the tooth in masticatory function with radiographic and clinical aspects compatible with normality.

Effectiveness of gutta-percha and Resilon in filling lateral root canals using thermomechanical technique

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of the rotary and/or oscillatory reciprocating systems in the morphological changes of narrow and curved molar root canals anatomy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influência do diâmetro foraminal do canal radicular, do tipo e da penetração de agulha, e do fluxo da solução irrigadora na limpeza e na extrusão apical

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo da diversidade microbiana e níveis de endotoxinas em lesões endo-periodontais

Pós-graduação em Odontologia Restauradora - ICT

Effects of Ciprofloxacin-containing Scaffolds on Enterococcus faecalis Biofilms

Introduction: Antibiotic-containing polymer-based nanofibers (hereafter referred to as scaffolds) have demonstrated great potential for their use in regenerative endodontics from both an antimicrobial and cytocompatibility perspective. This study sought to evaluate in vitro the effects of ciprofloxacin (CIP)-containing polymer scaffolds against Enterococcus faecalis biofilms. Methods: Human mandibular incisors were longitudinally sectioned to prepare radicular dentin specimens. Sterile dentin specimens were distributed in 24-well plates and inoculated with E. faecalisfor biofilm formation. Infected dentin specimens were exposed to 3 groups of scaffolds, namely polydioxanone (PDS) (control), PDS + 5 wt% CIP, and PDS + 25 wt% CIP for 2 days. Colony-forming units (CFU/mL) (n = 10) and scanning electron microscopy (SEM) (n -= 2) were performed to quantitatively and qualitatively assess the antimicrobial effectiveness, respectively. Results: PDS scaffold containing CIP at 25 wt% showed maximum bacteria elimination with no microbial growth, differing statistically (P < .05) from the control (PDS) and from PDS scaffold containing CIP at 5 wt%. Statistical differences (P < .05) were also seen for the CFU/mL data between pure PDS (5.92-6.02 log CFU/mL) and the PDS scaffold containing CIP at 5 wt% (5.39 5.87 log CFU/mL). SEM images revealed a greater concentration of bacteria on the middle third of the dentin specimen. after 5 days of biofilm formation. On scaffold exposures, SEM images showed similar results when compared with the CFU/mL data. Dentin specimens exposed to PDS + 25 wt% CIP scaffolds displayed a practically bacteria-free surface. Conclusions: On the basis of the data presented, newly developed antibiotic-containing electrospun scaffolds hold promise as an intracanal medicament to eliminate biofilm/infection before regenerative procedures.

Microbiological Profile Resistant to Different Intracanal Medications in Primary Endodontic Infections

Introduction: This clinical study aimed to determine the microbiological profile resistant to different intracanal medications in primary endodontic infections by using both microbiological culture and the checkerboard DNA-DNA hybridization technique. Methods: Twenty primarily infected root canals were selected and then instrumented before being randomly divided into 2 groups according to the intracanal medications: calcium hydroxide (Ca[OH](2)) or Ca(OH)(2) + chlorhexidine (CHX). Samples were collected before and after root canal procedures, which consisted in submitting them to microbiological culture and processing them for checkerboard DNA-DNA hybridization. Results: No differences were found between the Ca(OH)(2) (99.98%) and Ca(OH)(2) + CHX groups (99.76%) regarding the median percentage values for the reduction of cultivable bacteria. The most frequently detected species were Capnocytophaga ochracea (70%) and Fusobacterium nucleatum ssp. vincentii (70%) in the initial samples. After instrumentation, the most frequently detected species were E. faecium (60%). After root canal treatments using either Ca(OH)(2) or Ca(OH)(2) + CHX as intracanal medications, the most frequently detected species were E nucleatum ssp. vincentii (90%) and Enterococcus faecium (40%), respectively. Both treatments significantly decreased the number of bacterial species compared with the initial sample. However, this reduction was significantly greater in the Ca(OH)(2) + CHX group (P < .05). This difference was also observed when evaluating the total bacterial load (P < .05). Conclusions: The use of Ca(OH)(2) associated with CHX as an intracanal medication showed better results by acting on gram-positive and gram-negative microorganisms although such an action to eradicate enterococci should also be sought.

Endodontic retreatment: clinical comparison of reciprocating systems versus rotary system in disinfecting root canals

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of Insertion Techniques for Resin Cement and Mechanical Cycling on the Bond Strength Between Fiber Posts and Root Dentin

Purpose: To evaluate the effect of the insertion technique for resin cement and mechanical cycling on the bond strength between fiber posts and root dentin.Materials and Methods: Sixty-four single-rooted bovine teeth were endodontically prepared to receive glass-fiber posts. The insertion of cement into the root canal was performed using one of the following techniques: POS, insertion with the post; LEN, the use of a lentulo-type drill; EXP, insertion with a straight-tip explorer; or CEN, the use of a Centrix syringe. Half of the specimens were mechanically cycled. All specimens were sectioned into slices of 1.8 mm for the push-out test and 0.5 mm for analysis of the cement layer quality.Results: The insertion technique affected the interaction between factors (bond strength and mechanical cycling; p < 0.0001). Insertion of the Centrix syringe after mechanical cycling showed the highest bond values (13.6 +/- 3.2 MPa). Group-to-group comparisons for baseline and cycled conditions indicated that mechanical cycling significantly influenced the bond strength (p < 0.0001) of the POS and CEN groups. The quality of the cement layer did not differ between the techniques when evaluated in the middle (p = 0.0612) and cervical (p = 0.1119) regions, but did differ in the apical region (p = 0.0097), where the CEN group had better layer quality for the two conditions tested (baseline and cycled).Conclusion: The use of the Centrix syringe improved the homogeneity of the cement layer, reducing the defects in the layer and increasing adhesive strength values to dentin, even after mechanical cycling.

Clinical Influence of Different Intracanal Medications on Th1-type and Th2-type Cytokine Responses in Apical Periodontitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)