Bruna Paloma de Oliveira

Photodynamic therapy in combating the causative microorganisms from endodontic infections.

Photodynamic therapy (PDT) is presented as a promising antimicrobial therapy that can eliminate microorganisms present in endodontic infections. This treatment is based on the use of a nontoxic photosensitizing agent followed by irradiation of a resonant light source being capable of generating highly reactive species that are harmful to microorganisms. The purpose of this paper is to review the dental literature about the main factors that encompass the use of PDT combined with endodontic treatment for decontamination of the root canal system. A literature search was performed using the following index databases: PubMed, ISI Web of Knowledge and MedLine, between 2000 and 2014, looking for studies regarding antimicrobial action of PDT and its application to endodontic therapy. It was observed that despite numerous promising results, it is still necessary to establish different parameters so that PDT can be used with maximum effectiveness in eliminating microorganisms that cause endodontic infections.

The efficacy of photodynamic therapy and sodium hypochlorite in root canal disinfection by a single-file instrumentation technique

AIM The aim of this in vitro study was to evaluate the efficacy of photodynamic therapy (PDT) and sodium hypochlorite (NaOCl) in root canal disinfection by a single-file instrumentation technique. MATERIAL AND METHODS Seventy human single-rooted mandibular premolars were infected with Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans, and divided into seven groups (n=10) according to the protocol of disinfection used. Group 1: 1% NaOCl; Group 2: 5.25% NaOCl; Group 3: saline+PDT; Group 4: 1% NaOCl+PDT; Group 5: 5.25% NaOCl+PDT; Group 6: positive control; Group 7: negative control. For PDT, methylene blue (15μg/mL) remained in the root canal for 2min, followed by irradiation with diode laser. Samples were collected before and after instrumentation and plated in specific media cultures, to assess the presence or absence of microbial growth and determine the average reduction of viable microorganisms. RESULTS 5.25% NaOCl+PDT resulted in the highest number of specimens with no microbial growth. Also, 1% NaOCl and 1% NaOCl+PDT exhibited similar antimicrobial effects. Saline+PDT was not able to eliminate all microorganisms. There was statistical significant differences between the groups and the microorganisms. CONCLUSION The association of 5.25% NaOCl with PDT was the most effective treatment against microorganisms from endodontic infection in root canals instrumented by a single-file instrumentation technique. This result shows that PDT can be useful to improve the root canal disinfection.

Variation of Length of Styloid Process

El proceso estiloides es una proyeccion osea que tiene su origen en la porcion timpanica del hueso temporal y su elongacion es considerado una anomalia que puede relacionarse con la calcificacion de los ligamentos estilohioideo y estilomandibular, y de esta forma desarrollar una serie de sintomas que caracterizan al Sindrome de Eagle. El objetivo de este trabajo fue describir en tres craneos humanos la elongacion del proceso estiloides y dar a conocer al cirujano dentista esta anomalia, para que la incluya en su diagnostico, cuando se este presenta dolores atipicos de la cara o de la cavidad oral, y asi facilitar el mejor tratamiento en estos casos.

Micro–computed Tomographic Analysis of Apical Microcracks before and after Root Canal Preparation by Hand, Rotary, and Reciprocating Instruments at Different Working Lengths

Introduction: This study aimed to compare apical microcrack formation after root canal shaping by hand, rotary, and reciprocating files at different working lengths using micro–computed tomographic analysis. Methods: Sixty mandibular incisors were randomly divided into 6 experimental groups (n = 10) according to the systems and working lengths used for the root canal preparation: ProTaper Universal for Hand Use (Dentsply Maillefer, Ballaigues, Switzerland), HyFlex CM (Coltene‐Whaledent, Allstetten, Switzerland), and Reciproc (VDW, Munich, Germany) files working at the apical foramen (AF) and 1 mm short of the AF (AF − 1 mm). The teeth were imaged with micro–computed tomographic scanning at an isotropic resolution of 14 &mgr;m before and after root canal preparation, and the cross‐sectional images generated were assessed to detect microcracks in the apical portion of the roots. Results: Overall, 17 (28.3%) specimens presented microcracks before instrumentation. Apical microcracks were present in 1 (ProTaper Universal for Hand Use), 3 (Hyflex CM), and 2 (Reciproc) specimens when the instrumentation terminated at the AF. When instrumentation was terminated at AF − 1 mm, apical microcracks were detected in 3 (ProTaper Universal for Hand Use) and 4 (Hyflex CM and Reciproc) specimens. All these microcracks detected after root canal preparation were already present before instrumentation, and no new apical microcrack was visualized. For all groups, the number of slices presenting microcracks after root canal preparation was the same as before canal preparation. Conclusions: Root canal shaping with ProTaper Universal for Hand Use, HyFlex CM, and Reciproc systems, regardless of the working length, did not produce apical microcracks. HighlightsRoot sectioning studies have inconsistent reports on the impact on root dentin induced by instrumentation with hand, rotary, and reciprocating files.Micro–computed tomographic imaging was used to compare apical microcrack formation after root canal preparation with ProTaper Universal for Hand Use, HyFlex CM, and Reciproc systems working short or at the apical foramen.Neither the root canal preparation techniques nor the instrumentation lengths tested influenced the production of apical microcracks.

Detection of Apical Root Cracks Using Spectral Domain and Swept-source Optical Coherence Tomography

Introduction: This study aimed to evaluate the ability of 2 optical coherence tomographic (OCT) systems to detect apical dentinal microcracks. Methods: Twenty extracted human single‐rooted mandibular incisors were selected. After root canal preparation with an R40 Reciproc file (VDW, Munich, Germany), the specimens presenting apical microcracks were identified using micro–computed tomographic (micro‐CT) scanning as the gold standard. Then, the apical portions of the roots were imaged with spectral domain OCT (SD‐OCT) and swept‐source OCT systems, and the resulting images were blindly evaluated by 3 independent examiners to detect microcracks. The diagnostic performance of each OCT device was calculated, and statistical analysis was performed. Results: Based on the micro‐CT images, 12 (60%) roots presented dentinal microcracks in the apical region. The images generated by the OCT systems were able to show microcrack lines at the same location as the corresponding micro‐CT cross sections. Although the diagnostic performance of the SD‐OCT device was superior, there were no statistically significant differences between the 2 OCT devices (P > .05). Interexaminer agreement was substantial to almost perfect for the SD‐OCT system and moderate to almost perfect for the swept‐source OCT system, whereas intraexaminer agreement was substantial to almost perfect for both OCT devices. Conclusions: The detection ability verified for both OCT systems renders them promising tools for the diagnosis of apical microcracks.

Effect of Reciprocating Systems and Working Lengths on Apical Microcrack Development: a micro-CT Study

The objective of this study was to evaluate the effect of root canal preparation with single-file reciprocating systems at different working lengths on the development of apical microcracks using micro-computed tomographic (micro-CT) imaging. Forty extracted human mandibular incisors were randomly assigned to 4 groups (n=10) according to the systems and working length used to prepare the root canals: Group A - WaveOne Gold at apical foramen (AF), Group B - WaveOne Gold 1 mm short of the AF (AF-1 mm), Group C - Unicone (AF) and Group D - Unicone (AF-1 mm). Micro-CT scanning was performed before and after root canal preparation at an isotropic resolution of 14 µm. Then, three examiners assessed the cross-sectional images generated to detect microcracks in the apical portion of the roots. Apical microcracks were visualized in 3, 1, 1, and 3 specimens in groups A, B, C, and D, respectively. All these microcracks observed after root canal preparation already existed prior to instrumentation, and no new apical microcrack was detected. For all groups, the number of slices presenting microcracks after root canal preparation was the same as before canal preparation. Root canal preparation with WaveOne Gold and Unicone, regardless of the working length, was not associated with apical microcrack formation.

Prevalence of Asymptomatic Apical Periodontitis and its Association with Coronary Artery Disease in a Brazilian Subpopulation

Objective The aim of the present study was to determine the prevalence of asymptomatic apical periodontitis (AAP) and its association with coronary artery disease (CAD) in a Brazilian subpopulation, and to examine the correlation of AAP with gender, age and most frequently affected dental elements. Methods The data were collected from medical records of the patients (n = 1346) treated at the Specialization in Endodontics Clinic of the Federal University of Pernambuco in the period between 2003 and 2010. From each patient, the following variables were recorded: gender, age, endodontically compromised teeth, endodontic diseases diagnosed and the history of CAD. The data were analyzed using Pearsons chi-square test adopting a significance level of 5%. Results AAP was diagnosed in 574 patients (42.6%), corresponding to 641 teeth (40.1%). Both genders (p = 0.082), and all age groups (p = 0.190) were affected similarly. The upper incisors (52.8%, p <0.001) had a higher prevalence of AAP. The patients with AAP showed 1.45 times more chance of exhibiting CAD (p = 0.307). Conclusions The results pointed out that the prevalence of AAP in this population was high and similar to that observed in other countries. A positive association, but not statistically significant, between AAP and CAD was found.

Evaluation of Microbial Reduction in Root Canals Instrumented with Reciprocating and Rotary Systems

OBJECTIVE This in vitro study aimed to evaluate the efficacy of the disinfection of root canal systems carried out with Reciproc(TM) and ProTaper Universal(TM) systems using 1% sodium hypochlorite (NaOCl). METHODS Forty human single-rooted mandibular premolars were infected with Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans, and twenty were not infected. The specimens were randomly divided into 6 groups (n = 10): Group 1: ProTaper Universal(TM) + 1% NaOCl; Group 2 (positive control): ProTaper Universal(TM) + saline; Group 3 (negative control without microorganisms): ProTaper Universal(TM) + saline; Group 4: Reciproc(TM) + 1% NaOCl; Group 5 (positive control): Reciproc(TM) + saline; Group 6 (negative control without microorganisms): Reciproc(TM) + saline. Samples were collected before and after the completion of specific treatments, and plated in specific media cultures. The Fisher exact test was used for the statistical analysis of differences in terms of presence or absence of microbial growth among groups. For all tested pathogens, significant differences (p < 0.001) were verified between the instrumentation systems used. RESULTS ProTaper Universal(TM) associated with 1% NaOCl completely eliminated all microorganisms. Microbial growth, however, was observed when Reciproc(TM) was used associated with 1% NaOCl. CONCLUSION According to the protocol executed for this study, the Reciproc(TM) system associated with 1% NaOCl was not able to completely eliminate E. faecalis, P. aeruginosa, S. aureus and C. albicans from the root canal systems.