Cone-beam computed tomography in endodontics: from the specific technical considerations of acquisition parameters and interpretation to advanced clinical applications.

The implementation of imaging methods that enable sensitive and specific observation of anatomical structures has been a constant in the evolution of endodontic therapy. Cone-beam computed tomography (CBCT) enables 3-dimensional (3D) spatial anatomical navigation in the 3 volumetric planes (sagittal, coronal and axial) which translates into great accuracy for the identification of endodontic pathologies/conditions. CBCT interpretation consists of 2 main components: (i) the generation of specific tasks of the image and (ii) the subsequent interpretation report. A systematic and reproducible method to review CBCT scans can improve the accuracy of the interpretation process, translating into greater precision in terms of diagnosis and planning of endodontic clinical procedures. MEDLINE (PubMed), Web of Science, Google Scholar, Embase and Scopus were searched from inception to March 2023. This narrative review addresses the theoretical concepts, elements of interpretation and applications of the CBCT scan in endodontics. In addition, the contents and rationale for reporting 3D endodontic imaging are discussed.

Comparison of dynamic cyclic fatigue resistance of Reciproc® Blue and WaveOne® Gold after sterilization and/or immersion in sodium hypochlorite.

Background: This study aims to compare the cyclic fatigue resistance (CFR) of the Reciproc Blue and WaveOne Gold instruments under a dynamic cyclical fatigue test. Material and Methods: 210 Reciproc Blue "R25" and WaveOne Gold "primary" files were assigned into 7 groups (n =15) for each brand. Groups G: Files were not exposed to NaOCl or sterilization. Groups A and D: files were immersed for 3 minutes in NaOCl 1 and 3 times, respectively. Groups B and E: Files were autoclaved 1 and 3 times, respectively. Groups C and F: files were exposed to both, NaOCl immersion and autoclaving 1 and 3 times, respectively. Subsequently, files underwent a dynamic CFR test. The chemical composition of the files' surface from Group G was analysed by energy-dispersive X-ray spectroscopy (EDS). Cyclic fatigue resistance time was statistically analysed using 1-way and 2-way analyses of variance (ANOVA) and T-test. A p-value ≤0,05 was set to be statistically significant. Results: There was a significantly higher CFR of RB files than WOG in groups A, B, C, D and G (p<0.05). WOG files were superior to RB in group E (p>0.05). There were no statistically significant differences between files in group F (p>0.05). RB files from groups B, C, D, E and F had significantly lower resistance than new ones (Group G) (p<0.05). WaveOne Gold files exposed to 5 % NaOCl immersion in combination with sterilization cycles (Groups C and F) had significantly lower CFR than new ones (p<0.05). Reciproc Blue and WaveOne Gold NiTi alloys differed in atomic wt % of carbon, oxygen, nickel and titanium. Conclusions: The Reciproc Blue files outperformed the WaveOne Gold files in terms of CFR. The Reciproc Blue files were more vulnerable to the cycles of NaOCl immersion or autoclave sterilisation. The combined autoclaving and NaOCl cycles had the most significant impact on the mechanical properties of both files. Key words:Cyclic fatigue, Reciproc blue, Wave one gold, Dynamic test, Simulated channels, Sodium hypochlorite, Sterilization.

Effectiveness of photobiomodulation with low-level lasers on the acceleration of orthodontic tooth movement: a systematic review and meta-analysis of split-mouth randomised clinical trials.

Although several studies have evaluated the effect of low-level laser therapy (LLLT) on orthodontic movement acceleration, results are still inconsistent. Such inconsistencies may be attributed to the differences in the LLLT application protocols, especially in terms of wavelength ranges. Objective: (i) to assess the clinical effects of LLLT on the acceleration of orthodontic movement and (ii) to establish the most effective LLLT wavelength to accelerate tooth movement during orthodontic treatments. MEDLINE (PubMed), Scopus, ScienceDirect, and LILACS were searched from inception to October 2022. Inclusion criteria: Split-mouth randomised clinical trials (RCTs) on systemically healthy patients reporting the effect of LLLT in accelerating orthodontic movements, specifically retraction of canines. The risk of bias was assessed using RoB-2. A random effect model was applied. Nineteen RCTs met the inclusion criteria for qualitative synthesis, and eighteen RCTs were included in the quantitative synthesis. Seventeen studies were rated as at some concerns of bias and two studies were classified as having a low risk of bias. In general terms, this systematic review and meta-analysis presents a moderate risk of bias. Findings of this systematic review and meta-analysis point to a tendency for faster orthodontic dental movement in the groups receiving LLLT treatment during the first (OR of 0.28 95% CI (0.07 to 0.48)), second (OR of 0.52 95% CI (0.31 to 0.73)), and third (OR of 0.41 95% CI (0.03 to 0.79)) month follow-up. Wavelengths ≤ 810 nm and energy density values ≤ 5.3 J/cm2 were associated with faster orthodontic tooth movement.

Comparative outcomes of platelet concentrates and blood clot scaffolds for regenerative endodontic procedures: A systematic review of randomized controlled clinical trials.

Background: The main objective of this systematic review is to evaluate the effectiveness of platelet concentrates -Platelet-rich plasma (PRP) or Fibrin-rich plasma (PRF)- compared with blood clot (BC) as scaffolds for maturogenesis, in patients with immature permanent teeth with or without AP, in terms of the criteria for pulp revascularization success. Material and Methods: We reviewed randomized controlled clinical trials comparing regenerative endodontic therapies (maturogenesis) based on PRP or PRF versus the conventional BC approach, in necrotic teeth with or without apical periodontitis (AP) under clinical and radiographic criteria. We performed a strategic search in MEDLINE (PUBMED), EMBASE, and ISI Web of Science from inception to October 2022. This systematic review of the literature was developed following the Cochrane Collaboration and PRISMA statement recommendations. We used the Cochrane risk of bias tool v2 to assess the included studies' quality. We performed a qualitative synthesis of the evidence. Results: Ten randomized controlled clinical trials were included in this systematic review. Analyses of these studies suggest that maturogenesis is a successful therapy regardless of the method employed. However, further research should be conducted with more suitable research methodologies and more homogenous data for meta-analysis. Conclusions: Results from this systematic review suggest that BC maturogenesis approaches yield similar clinical and radiographic outcomes when compared to Platelet-concentrates based therapies (PRP and PRF). Key words:Maturogenesis, Revascularization, Platelet-rich plasma, Fibrin-rich plasma, blood clot, systematic review.

Effectiveness, efficiency, and apical extrusion of 2 rotaries and 2 reciprocating systems in removing filling material during endodontic retreatment. A systematic review.

Background: This systematic review investigated the effectiveness, efficiency and apical extrusion of the debris of two rotary and two reciprocating single-file systems used for the removal of filling material from straight root canals. Material and Methods: A literature search was performed in the Medline, ISI Web of Science, and Scopus databases for relevant articles matching the keyword search strategy. Effectiveness was determined with studies dealing with the ability of the instruments to remove filling material from root canals. Efficiency was assessed with studies dealing with the time needed to completely remove the root canal filling, and apical extrusion was determined with studies that measured the amount of filling material extruded through the apex. Results: From the 424 articles initially found, 406 were excluded for being non-relevant or not fulfilling the selection criteria. Another 9 articles were excluded after methodology evaluation. Finally, 9 studies were included in the systematic review. Conclusions: None of the reviewed systems is effective to completely remove the filling materials from straight root canals, and all systems appear to be equally time-efficient, although this variable shows different results. In terms of apical extrusion, the analyzed reciprocating systems extrude more material toward the periapical tissues than the continuous rotation systems. Key words:Systematic review, rotary files, reciprocating files, apical extrusion, endodontic retreatment.

The Paradigm of the Inflammatory Radicular Cyst: Biological Aspects to be Considered.

Inflammatory radicular cysts (IRCs) are chronic lesions that follow the development of periapical granulomas (PGs). IRCs result from multiple inflammatory reactions led initially by several pro-inflammatory interleukins and growth factors that provoke the proliferation of epithelial cells derived from epithelial cell rests of Malassez present in the granulomatous tissue, followed by cyst formation and growth processes. Multiple theories have been proposed to help explain the molecular process involved in the development of the IRC from a PG. However, although multiple studies have demonstrated the presence of epithelial cells in most PGs, it is still not fully understood why not all PGs turn into IRCs, even though both are stages of the same inflammatory phenomenon and receive the same antigenic stimulus. Histopathological examination is currently the diagnostic gold standard for differentiating IRCs from PGs. Although multiple studies have evaluated the accuracy of non-invasive or minimally invasive methods in assessing the histopathological nature of the AP before the intervention, these studies' results are still controversial. This narrative review addresses the biological insights into the complex molecular mechanisms of IRC formation and its histopathological features. In addition, the relevant inflammatory molecular mediators for IRC development and the accuracy of non-invasive or minimally invasive diagnostic approaches are summarised. (EEJ-2022-03-041).

Association between cigarette smoking and the prevalence of post-endodontic periapical pathology: a systematic review and meta-analysis.

Objectives: This systematic review and meta-analysis aimed to assess the association of cigarette smoking with the prevalence of post-endodontic apical periodontitis in humans. Materials and Methods: We searched through PubMed/Medline, Web of Science, and Scopus from inception to December 2020. Risk of bias was performed by using the Newcastle-Ottawa Scale for cross-sectional, cohort, and case-control studies. We performed the statistical analysis in Review Manager 5.3 (RevMan 5.3). Results: 6 studies met the inclusion criteria for qualitative and quantitative synthesis. Statistical analysis of these studies suggests that there were no differences in the prevalence of post endodontic apical periodontitis (AP) when comparing non-smokers vs smoker subjects regarding patients (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.31-1.49; I2 = 58%) and teeth (OR, 1.71; 95% CI, 0.99-2.93; I2 = 72%). Conclusions: Our findings suggest that there was no association between cigarette smoking and post-endodontic apical periodontitis, as we did not find statistical differences in the prevalence of post-endodontic AP when comparing non-smokers vs smoker subjects. Therefore, smoking should not be considered a risk factor associated with endodontic failure.

Elevación de seno maxilar sin injerto y colocación simultánea de implante dental / Graftless maxillary sinus lift with simultaneous dental implant placement

Introducción: La elevación de seno maxilar con implante dental simultáneo, sin el uso de substitutos óseos, ha retomado la teoría del potencial de neoformación ósea, que el coágulo de sangre alojado bajo la membrana de Schneider por sí solo presenta. Excluyendo así la necesidad de materiales exógenos. Objetivo: Exponer la efectividad de la elevación de seno maxilar con implante dental simultáneo, sin el uso de injerto, mediante la evaluación de la cantidad de ganancia ósea vertical. Presentación de casos: Caso 1: Paciente de 62 años, género femenino, que fue sometida a una elevación de seno maxilar sin injerto e implante dental simultáneo, con técnica de ventana lateral debido a altura ósea reducida de 5,24 mm. Luego del período de seguimiento tomográfico de 12 meses, después de la carga protésica, se logró una altura ósea vertical de 10,2 mm, lo que dio como resultado una ganancia ósea vertical de 4,96 mm. Caso 2: Paciente de 48 años, género femenino, que fue sometida a una elevación de seno maxilar sin injerto e implante dental simultáneo, con técnica transalveolar, mediante el uso de piezoeléctrico debido a una altura ósea reducida de 8,33 mm. Luego del período de seguimiento radiográfico de 4 meses, antes de la carga protésica, se logró una altura ósea vertical de 11,55 mm, lo que dio como resultado una ganancia ósea vertical de 3,19 mm. Conclusiones: Con base en estos 2 informes de casos, la elevación de seno maxilar e implante dental simultáneo sin injerto se asocian con la reducción de la morbilidad quirúrgica, menor probabilidad de procesos infecciosos y menor costo de la cirugía. Por lo tanto, puede considerarse una alternativa quirúrgica para la colocación de implantes en el maxilar posterior superior debido a deficiencias óseas verticales, independientemente de la técnica (lateral o transalveolar(AU)

Introduction: Maxillary sinus lift with simultaneous dental implantation without using bone substitutes, reapproaches the theory about the bone neoformation potential of the blood clot housed under the Schneider membrane, all by itself, thus excluding the need to use exogenous materials. Objective: Discuss the effectiveness of graftless maxillary sinus lift with simultaneous dental implant placement through an evaluation of the amount of vertical bone gain. Case presentation: Case 1: Female 62-year-old patient undergoing graftless maxillary sinus lift with simultaneous dental implantation by lateral window technique due to a reduced bone height of 5.24 mm. After a 12-month tomographic follow-up period subsequent to prosthetic loading, a 10.2 mm vertical bone height was achieved, resulting in 4.96 mm vertical bone gain. Case 2: Female 48-year-old patient undergoing graftless maxillary sinus lift with simultaneous dental implantation by transalveolar technique using a piezoelectric generator due to a reduced bone height of 8.33 mm. After a 4-month radiographic follow-up period, before prosthetic loading, an 11.55 mm vertical bone height was achieved, resulting in 3.19 mm vertical bone gain. Conclusions: According to these two case reports, graftless maxillary sinus lifting with simultaneous dental implantation is associated to reduced surgical morbidity, a lesser probability of infectious processes and lower surgical costs. It may therefore be considered to be a surgical alternative for implant placement in the posterior maxilla due to vertical bone deficiencies, regardless of the technique used (lateral or transalveolar(AU)

Three-dimensional analysis of the root canal preparation with Reciproc Blue®, WaveOne Gold® and XP EndoShaper®: a new method in vivo.

BACKGROUND: The purpose of this study was to evaluate the changes in canal volume after root canal preparation in vivo with 3 different single-file techniques (Reciproc-Blue®, WaveOne-Gold® and XP-EndoShaper®), with a new method using CBCT and 3D reconstruction. METHODS: In this prospective study, thirty human lower premolars from healthy patients were used, in which extraction was indicated for orthodontic reasons. All the teeth used were caries- and restoration-free with complete root development, without signs of periodontal disease or traumatic occlusion, and with only one straight canal (up to 25º curvature). Teeth were randomly divided into three different groups: Reciproc-Blue, WaveOne-Gold and XP-EndoShaper. CBCT scans before root canal preparation were used to create a 3D reconstruction with RHINOCEROS 5.0 software to assess the initial canal volume, and then compared with 3D reconstructions after canal preparation to measure the increase in canal volume. Student's t test for paired data were used to determine statistically significant differences between the before and after canal volumes. Anova test was used to determine statistically significant differences in the percentage of canal volume increase between the groups and Tukey's post-hoc test were used to paired comparison. RESULTS: Reciproc-Blue showed the higher increase in canal volume, followed by WaveOne-Gold and XP-EndoShaper (p = 0.003). XP-EndoShaper did not show a statistically significant increase in canal volume after root canal preparation (p = 0.06). CONCLUSION: With this model, Reciproc-Blue showed higher increase in root canal volume, followed by WaveOne-Gold, while XP-EndoShaper did not significantly increase root canal volume during preparation.

Association between type 2 diabetes mellitus and the evolution of endodontic pathology.

OBJECTIVE: The purpose of the present study was to assess the influence of type 2 diabetes mellitus (DM) on the evolution of pulpal and periapical pathology. METHOD AND MATERIALS: Two reviewers independently conducted a systematic search for articles published between 1 January 2001 and 31 December 2018 on MEDLINE/PubMed, ISI Web of Science, and Scopus databases. An additional manual search was also carried out. RESULTS: Ten studies fulfilling the inclusion criteria were included in the review (two longitudinal studies with 1-year follow-up comparing the success of primary root canal treatment between type 2 diabetic patients and non-diabetic patients, and eight cross-sectional studies). Analysis of the ten studies showed that inadequate control of type 2 DM may predispose and influence the inflammatory pulpal and periapical disease evolution. CONCLUSIONS: The present systematic review suggests that there are biologic bases to suggest that type 2 DM may act as a risk factor for developing an endodontic pathology, affecting the course of the disease in terms of susceptibility, prevalence, progression, and tissue healing capacity as a consequence of a disrupted immune response. However, more well-designed clinical investigations carrying out suitable research methodologies are needed to elucidate the influence of type 2 DM on the pulpal and periapical disease evolution.

Detection and molecular characterization of Clostridium difficile ST 1 in Buenos Aires, Argentina.

Thirty one C. difficile isolates recovered in 2015 were characterized. Nineteen/31 were positive for tcdA/B, among them, 4 isolates were also positive for CDT coding genes. Two/4 cdtA/B positives isolates corresponded to ST 1 resembling BI/NAP1/027/ST 1 strain, while the others corresponded to ST 226 and ST 377.

Comparison between 940 nm Laser Diode and Topical 5% Potassium Nitrate for Tooth Desensitization. Randomized Controlled Clinical trial / Comparación entre el láser diodo de 940 nm y el nitrato de potasio tópico al 5% para la desensibilización dental. Estudio clínico controlado aleatorizado

Objetivo: Comparar la efectividad de las terapias de sensibilización dental que usan láser diodo 940 nm y nitrato de potasio en pacientes con síntomas de hipersensibilidad dental (HD). Métodos: Este ensayo clínico aleatorizado incluyó 30 pacientes quienes habían recibido previamente terapia periodontal básica y presentaban recesiones gingivales clases I y II (Miller 1985) con síntomas de HD. La muestra fue asignada aleatoriamente a los dos grupos. Al primero (n=15) le fue aplicado láser 940 nm por 90 segundos en la superficie de la recesión, y se les suministró un tubo de glicerina para ser aplicado diariamente y evitar la generación de sesgos. El segundo grupo (n=15) recibió láser inactive como placebo y se le suministró un gel desensibilizante que contenía nitrato de potasio 0,5 g para aplicar dos veces al día durante 14 días. Se realizaron controles a los 15 minutos, 8 días, 15 días y 4 semanas. Los datos obtenidos se registraron en una table en Excel. Se emplearon U de Mann Whitney U y t Student para comparar los grupos (p=0,05). Resultados: Todos los pacientes del estudio mostraron reducción de la HD, diferencias que fueron estadísticamente significativas (p<0,01) entre los dos grupos intervenidos. Conclusiones: Ambos, el láser diodo y el nitrato fueron efectivos en el manejo posterior a la terapia periodontal para el manejo de la HD. Sin embargo, las diferencias fueron mayores para el grupo de terapia con láser.

Purpose: To compare the effectiveness of two dental desensitization therapies, 940nm laser diode and potassium nitrate, in patients with dental hypersensitivity (DH) symptoms. Methods: This randomized clinical trial included 30 patients who initially underwent basic periodontal therapy and presented gingival recessions Class I and II (Miller 1985) with symptoms of DH. Subjects were randomly assigned into two groups. The first group (n = 15) received laser 940 nm application for 90 seconds on the surface of the recession and were given a tube of glycerin to be applied daily in order to avoid generating bias. Patients in the second group (n = 15) were exposed to inactive laser simulating the actual application of the laser, and they were given a desensitizing gel containing 0.5 g of potassium nitrate to be applied twice daily during 14 days. Controls were carried out at 15 minutes, 8 days, 15 days, and 4 weeks. Data obtained were filled out in an Excel table. For comparison between groups the Mann Whitney U and t student tests were used (p=0.05). Results: All patients involve in the study experienced reduction in DH (p<0.01) and differences between the two interventions performed. Conclusions: Laser and nitrate therapies were effective to manage DH after basic periodontal therapy. However, a statistically significant higher sensitivity reduction was observed in laser therapy group.

The effect of tooth bleaching on substance P expression in human dental pulp.

The purpose of this study was to quantify the effect of tooth bleaching on substance P (SP) expression in healthy human dental pulp. Forty pulp samples were obtained from healthy premolars in which extraction was indicated for orthodontic reasons. Thirty of these premolars were assigned into three different tooth-bleaching protocols: group 1 (n = 10): Opalescence Xtra Boost (Ultradent Products, South Jordan, UT) (38% H(2)O(2)) for 15 minutes; group 2 (n = 10): Lase Peroxide (DMC, Brazil) (35% H(2)O(2)) activated with infrared laser diode (Biolux; BioArt, Brazil) for 3 minutes, and group 3 (n = 10): Zoom! Whitening System (Discuss Dental, Culver City, CA) (25% H(2)O(2)) light activated for 20 minutes. The remaining 10 healthy premolars serve as a control group. Teeth were anesthetized immediately after bleaching and were extracted 10 minutes later. All pulp samples were processed and SP was measured by radioimmunoassay. Greater SP expression was found in the Zoom! Whitening System, followed by the Lase Peroxide group, Opalescence Xtra Boost, and the lower SP values were for the control group. Analysis of variance showed statistically significant differences between groups (p = 0.0001). Tukey HSD post hoc tests showed significant differences in the light (p < 0.01) and laser (p < 0.05) activated bleaching systems when compared with control values. It can be concluded that light- and laser-activated tooth-bleaching systems increase SP expression in human dental pulp significantly higher than normal values.