Root canal treatment of dilacerated second maxillary premolars : planning the shaping procedure

This article aims at investigating endodontic anatomical variants in the human maxillary premolars allowing the planning of safer and faster shaping procedures. Endodontic literature describes maxillary 2nd premolars as some of the easiest teeth to treat, as they have either one or two straight canals. Rarely they may sometimes have two dilacerated canals. This paper reports two clinical cases of maxillary premolars whose anatomy is quite unusual. In the first case report we describe a maxillary 2nd premolar with a single root and two dilacerated merged canals. The second case report concerns the retreatment of a maxillary 2nd premolar with a single root and two independent dilacerated canals, and even some lateral canal. In dilacerated anatomy, canal scouting step might cause some procedural errors. To avoid these procedural errors, we propose a modern step down technique using at first a rotary NiTi glide path instrument, to go up to the 2/3 of root canal length or until to the first impediment. This would allow an easy apical scouting of the last millimeters of endodont and increase the volume of the irrigants in the apical region. In this way since a safer and faster shaping procedure could be performe

A finite element model of abdominal human tissue for improving the accuracy in insulin absorption assessment: A feasibility study

A Finite Element Model of the human abdomen biomechanics for patients undergoing diabetes therapies was developed. In particular, FEM was used to improve a previous insulin absorption measurement method based on bioimpedance spectroscopy (BIS). As a matter of facts, the noise introduced during the insulin injection phase significantly affects the BIS measurements. The noise, due to the pressure exerted on the abdomen tissue, arises sensibility issues on the signal correlated to the drug presence under the skin. In this study, the abdomen is modeled with three layers (skin, fat and muscle). A feasibility study about the decoupling of the mechanical deformation and the electrical dynamics is presented in order to model the effect of mechanical uncertainty sources (e.g., pressure exerted during the injection phase and/or breathing) on the impedance measurements. The proposed simplified model is realised by referring to the average values of skin, fat and muscle thickness, along with mechanical abdomen parameters al-ready presented and validated in scientific literature. The obtained results confirm the possibility to decouple me-chanical and electrical analyses when the excitation voltage is characterized by a frequency higher than 1 kHz. The results will be used to improve the accuracy of an exhaustive approach, already developed by the authors, for real-time insulin absorption measurement

Microscopic and chemical assessments of the filling ability using five different filling techniques

Évaluer la capacité de remplissage des cinq différentes techniques d’obturation canalaire dans l’obturation des canaux ovales. Matériel et méthodes : Un total de 220 molaires mandibulaires, avec 1 canal dans la racine distale, a été sélectionné. Chaque canal a été mise en forme jusqu’à la longueur de travail en utilisant un système mono-instrument le WaveOne Gold Primary Les dents préparées ont été divisées au hasard en cinq groupes égaux (n = 40 par groupe) pour l'obturation: condensation à onde continue (CWC), technique avec tuteur GuttaCore (GC), technique avec tuteur Thermafil (TH), technique utilisant un cône unique (SC), condensation hydraulique à froid (CHC). Les pourcentages de GPFA, SFA et VA ainsi que la présence des matériaux d’obturation à l’intérieur des tubulis dentinaires (tag)à longueur de travail (LT) -4mm et -2 mm a été évalué à par microscopie numérique optique, microscopie électronique à balayage (SEM) et microanalyse par rayons X à dispersion d'énergie (EDX). Analyse statistique : Les données collectées ont été analysées avec la version 11.2 de SigmaPlot (Systat Software, Inc., San José, CA, USA). Les pourcentages de GPFA, SFA, VA correspondant aux différentes groupes ont été comparés en utilisant le test de Kruskal-Wallis avec α=0,05. Résultats: à LT-4 et LT-2 mm, cette étude à montré une différence statistiquement significative en terme de capacité d’obturation pour le cinq techniques. À LT-4, les groupes GC et TH ont montré une différence statistiquement significative par rapport aux trois autres groupes en terme de GPFA et SFA. En terme de VA, il y a une différence statistiquement significative avec les groupes SC et CHC tandis qu’aucune différence n’a été démontrée entre les groupes GC , TH et CWC . À LT-2, les groupes GC et TH ont montré une différence statistiquement significative par rapport aux trois autres groupes en terme de GPFA, SFA, VA. Conclusion : Cette étude montre clairement que les obturations par GC et TH sont en mesure de remplir les canaux ovales d’une manière plus appropriée que les autres techniques d’obturation. Les groupes GC et TH, à LT -4 et -2mm, présentaient des tags de gutta-percha à l’intérieur des tubulis dentinaires. La présence de tags de gutta-percha à l’intérieur des tubulis dentinaires (à la place de tags de ciment beaucoup plus vulnérables) pourrait se comporter comme une barrière physique, capable de sceller les bactéries à l’intérieur des tubulis et surtout non résorbable dans le temps.Assess the filling ability in oval-shaped canals using five different filling techniques. Materials and Methods : 220 human mandibular first molars with one distal oval canal were selected. Distal Canals were shaped using WaveOne Gold Primary. The prepared teeth were randomly divided in four equal groups (n = 40) for obturation : Continuous Wave Condensation (CWC), GuttaCore carrier based technique (GC), Thermafil (TH) carrier based technique, Single Cone technique (SC), Cold hydraulic Condensation (CHC). The proportions of gutta-percha filled areas (GPFA), sealer filled areas (SFA), void areas (VA) and the tags into dentinal tubules at 4 mm and 2 mm were analyzed by Optical numeric microscope, SEM and EDX. Statistical analysis : they were compared by Kruskal-Wallis one-way ANOVA on ranks, with statistical significance set at α = 0.05. Results : At 4 and 2 mm from the apex, this study discloses statistically different filling ability for the five techniques. At 4 mm from the apex, the GC et TH groups showed significantly higher PGFAs than lateral condensation and System B techniques. The GC et TH groups showed a statistically significance difference compared with the others three groups in terms of higher PGFA, lower SFA. It showed a statistically significance difference with SC and CHC groups in term of VA. At 2 mm level from the apex, the GC et TH groups showed a statistically significance differece compared with the others three groups in terms of higher PGFA, lower SFA and VA. Conclusions : GC obturation is able to fill oval-shaped canals in a more appropriate way than the other filling techniques. GC was the only group which showed the presence of gutta-tags at 4 and 2 mm from the apex. The gutta- percha tags could behave as a physical barrier able to entomb bacteria

Mise au point et évaluation microscopique d'une méthode d'obturation canalaire optimale

Assess the filling ability in oval-shaped canals using five different filling techniques. Materials and Methods : 220 human mandibular first molars with one distal oval canal were selected. Distal Canals were shaped using WaveOne Gold Primary. The prepared teeth were randomly divided in four equal groups (n = 40) for obturation : Continuous Wave Condensation (CWC), GuttaCore carrier based technique (GC), Thermafil (TH) carrier based technique, Single Cone technique (SC), Cold hydraulic Condensation (CHC). The proportions of gutta-percha filled areas (GPFA), sealer filled areas (SFA), void areas (VA) and the tags into dentinal tubules at 4 mm and 2 mm were analyzed by Optical numeric microscope, SEM and EDX. Statistical analysis : they were compared by Kruskal-Wallis one-way ANOVA on ranks, with statistical significance set at α = 0.05. Results : At 4 and 2 mm from the apex, this study discloses statistically different filling ability for the five techniques. At 4 mm from the apex, the GC et TH groups showed significantly higher PGFAs than lateral condensation and System B techniques. The GC et TH groups showed a statistically significance difference compared with the others three groups in terms of higher PGFA, lower SFA. It showed a statistically significance difference with SC and CHC groups in term of VA. At 2 mm level from the apex, the GC et TH groups showed a statistically significance differece compared with the others three groups in terms of higher PGFA, lower SFA and VA. Conclusions : GC obturation is able to fill oval-shaped canals in a more appropriate way than the other filling techniques. GC was the only group which showed the presence of gutta-tags at 4 and 2 mm from the apex. The gutta- percha tags could behave as a physical barrier able to entomb bacteria.Évaluer la capacité de remplissage des cinq différentes techniques d’obturation canalaire dans l’obturation des canaux ovales. Matériel et méthodes : Un total de 220 molaires mandibulaires, avec 1 canal dans la racine distale, a été sélectionné. Chaque canal a été mise en forme jusqu’à la longueur de travail en utilisant un système mono-instrument le WaveOne Gold Primary Les dents préparées ont été divisées au hasard en cinq groupes égaux (n = 40 par groupe) pour l'obturation: condensation à onde continue (CWC), technique avec tuteur GuttaCore (GC), technique avec tuteur Thermafil (TH), technique utilisant un cône unique (SC), condensation hydraulique à froid (CHC). Les pourcentages de GPFA, SFA et VA ainsi que la présence des matériaux d’obturation à l’intérieur des tubulis dentinaires (tag)à longueur de travail (LT) -4mm et -2 mm a été évalué à par microscopie numérique optique, microscopie électronique à balayage (SEM) et microanalyse par rayons X à dispersion d'énergie (EDX). Analyse statistique : Les données collectées ont été analysées avec la version 11.2 de SigmaPlot (Systat Software, Inc., San José, CA, USA). Les pourcentages de GPFA, SFA, VA correspondant aux différentes groupes ont été comparés en utilisant le test de Kruskal-Wallis avec α=0,05. Résultats: à LT-4 et LT-2 mm, cette étude à montré une différence statistiquement significative en terme de capacité d’obturation pour le cinq techniques. À LT-4, les groupes GC et TH ont montré une différence statistiquement significative par rapport aux trois autres groupes en terme de GPFA et SFA. En terme de VA, il y a une différence statistiquement significative avec les groupes SC et CHC tandis qu’aucune différence n’a été démontrée entre les groupes GC , TH et CWC . À LT-2, les groupes GC et TH ont montré une différence statistiquement significative par rapport aux trois autres groupes en terme de GPFA, SFA, VA. Conclusion : Cette étude montre clairement que les obturations par GC et TH sont en mesure de remplir les canaux ovales d’une manière plus appropriée que les autres techniques d’obturation. Les groupes GC et TH, à LT -4 et -2mm, présentaient des tags de gutta-percha à l’intérieur des tubulis dentinaires. La présence de tags de gutta-percha à l’intérieur des tubulis dentinaires (à la place de tags de ciment beaucoup plus vulnérables) pourrait se comporter comme une barrière physique, capable de sceller les bactéries à l’intérieur des tubulis et surtout non résorbable dans le temps

Microscopic and chemical assessments of the filling ability using five different filling techniques

Évaluer la capacité de remplissage des cinq différentes techniques d’obturation canalaire dans l’obturation des canaux ovales. Matériel et méthodes : Un total de 220 molaires mandibulaires, avec 1 canal dans la racine distale, a été sélectionné. Chaque canal a été mise en forme jusqu’à la longueur de travail en utilisant un système mono-instrument le WaveOne Gold Primary Les dents préparées ont été divisées au hasard en cinq groupes égaux (n = 40 par groupe) pour l'obturation: condensation à onde continue (CWC), technique avec tuteur GuttaCore (GC), technique avec tuteur Thermafil (TH), technique utilisant un cône unique (SC), condensation hydraulique à froid (CHC). Les pourcentages de GPFA, SFA et VA ainsi que la présence des matériaux d’obturation à l’intérieur des tubulis dentinaires (tag)à longueur de travail (LT) -4mm et -2 mm a été évalué à par microscopie numérique optique, microscopie électronique à balayage (SEM) et microanalyse par rayons X à dispersion d'énergie (EDX). Analyse statistique : Les données collectées ont été analysées avec la version 11.2 de SigmaPlot (Systat Software, Inc., San José, CA, USA). Les pourcentages de GPFA, SFA, VA correspondant aux différentes groupes ont été comparés en utilisant le test de Kruskal-Wallis avec α=0,05. Résultats: à LT-4 et LT-2 mm, cette étude à montré une différence statistiquement significative en terme de capacité d’obturation pour le cinq techniques. À LT-4, les groupes GC et TH ont montré une différence statistiquement significative par rapport aux trois autres groupes en terme de GPFA et SFA. En terme de VA, il y a une différence statistiquement significative avec les groupes SC et CHC tandis qu’aucune différence n’a été démontrée entre les groupes GC , TH et CWC . À LT-2, les groupes GC et TH ont montré une différence statistiquement significative par rapport aux trois autres groupes en terme de GPFA, SFA, VA. Conclusion : \u2028Cette étude montre clairement que les obturations par GC et TH sont en mesure de remplir les canaux ovales d’une manière plus appropriée que les autres techniques d’obturation. \u2028Les groupes GC et TH, à LT -4 et -2mm, présentaient des tags de gutta-percha à l’intérieur des tubulis dentinaires. La présence de tags de gutta-percha à l’intérieur des tubulis dentinaires (à la place de tags de ciment beaucoup plus vulnérables) pourrait se comporter comme une barrière physique, capable de sceller les bactéries à l’intérieur des tubulis et surtout non résorbable dans le temps.Assess the filling ability in oval-shaped canals using five different filling techniques. Materials and Methods : 220 human mandibular first molars with one distal oval canal were selected. Distal Canals were shaped using WaveOne Gold Primary. The prepared teeth were randomly divided in four equal groups (n = 40) for obturation : Continuous Wave Condensation (CWC), GuttaCore carrier based technique (GC), Thermafil (TH) carrier based technique, Single Cone technique (SC), Cold hydraulic Condensation (CHC). The proportions of gutta-percha filled areas (GPFA), sealer filled areas (SFA), void areas (VA) and the tags into dentinal tubules at 4 mm and 2 mm were analyzed by Optical numeric microscope, SEM and EDX. Statistical analysis : they were compared by Kruskal-Wallis one-way ANOVA on ranks, with statistical significance set at α = 0.05. Results : At 4 and 2 mm from the apex, this study discloses statistically different filling ability for the five techniques. At 4 mm from the apex, the GC et TH groups showed significantly higher PGFAs than lateral condensation and System B techniques. The GC et TH groups showed a statistically significance difference compared with the others three groups in terms of higher PGFA, lower SFA. It showed a statistically significance difference with SC and CHC groups in term of VA. At 2 mm level from the apex, the GC et TH groups showed a statistically significance differece compared with the others three groups in terms of higher PGFA, lower SFA and VA. Conclusions : GC obturation is able to fill oval-shaped canals in a more appropriate way than the other filling techniques. GC was the only group which showed the presence of gutta-tags at 4 and 2 mm from the apex. The gutta- percha tags could behave as a physical barrier able to entomb bacteria

Unusual Maxillary First Molars with C-Shaped Morphology on the Same Patient: Variation in Root Canal Anatomy

A maxillary first molar should be considered a four-canal tooth until proved otherwise; however, a clinician should also be aware of the possibility of the presence of C-shaped root canal configuration with or without possibility of splitting into two or three canals. The two clinical cases reported in this paper describe the endodontic treatment of two maxillary first molars, on the same patient, with uncommon anatomy: the first case is about a maxillary first molar with only one C-shaped root and one oval canal with a large buccolingual diameter, a C1 type according to Fan's classification; the second case, about the contralateral maxillary first molar, is probably the first case documented of a maxillary first molar with a C-shaped root canal and C-shaped root with complete fusion of the three roots, having a C3 configuration

Improved single visit management of old infected iatrogenic root perforations using Biodentine®

Aim: The aim of this retrospective observational case series study was to evaluate the middle term outcomes on endodontic management of old infected iatrogenic root perforations using Biodentine. The treatments were always concluded in a single visit, without previous medication with calcium hydroxide. Our goal was to facilitate this kind of treatments and to make them more reproducible and manageable even for a general practitioner or a student. Methodology and methods: Between January 2011 and June 2016, 51 patients with old infected root perforations have been enrolled. All the treatments were performed using Biodentine in a single visit. Infected root perforation repair was performed by supervised dental students (39%) or a qualified endodontist (61%), employing surgical microscope magnification during treatments. After the treatment, the 51 patients were monitored for 18–64 months. We used clinical and radiographic examinations. Results: Of 51 examined teeth, 48 (94%) were classified as healed. The time, the size and the location of the perforations did not have a significant effect on the outcome. We proved the ineffectiveness of the null hypothesis. According to this latter, the single visit treatment of old infected perforations with Biodentine was inadequate. Conclusions: In single visit treatments, Biodentine seems to provide a biocompatible and effective seal in acidic environment, in accidental root perforations, even if the treatment is performed by an inexperienced operator and regardless of the location, the size and the time of occurrence of the perforation. Riassunto: Obiettivi: Lo scopo di questo studio osservazionale retrospettivo è stato quello di valutare la percentuale di guarigione a medio termine nel trattamento delle “old infected” perforazioni con contaminazione batterica usando biodentine. Il trattamento di tutte le perforazioni è stato fatto in seduta singola, senza medicazione con idrossido di calcio. Altro obiettivo è stato quello di facilitare questo tipo di trattamenti, rendendoli riproducibili e fattibili anche per un dentista generico o uno studente. Materiali e metodi: Tra Gennaio 2011 e Giugno 2016, abbiamo selezionato 51 pazienti con “old infected” perforationi. Ogni caso é stato trattato con Biodentine in singola seduta. Il 39% dei casi é stato trattato da studenti della clinica universitaria sotto la supervisione di un tutor senior, mentre il 61% da un endodontista qualificato, usando il microscopio operatorio durante ogni fase del trattamento. Dopo il trattamento, i 51 pazienti sono stati monitorati tra 18 e 64 mesi, con esami radiografici e clinici. Risultati: Fra i 51 denti esaminati, 48 (94%) sono stati classificati come guariti. Nel nostro studio il tempo, la dimensione e la localizzazione della perforazione non hanno avuto alcun valore prognostico. Abbiamo dunque rigettato l’ipotesi nulla, secondo la quale il trattamento in singola visita delle “old infected” perforazioni con Biodentine fosse inadequato. Conclusioni: Il trattamento delle “old infected” perforazioni in ambiente acido in singola visita con Biodentine sembra assicurare un sigillo biocompatibile e tridimensionale della perforazione anche se il trattamento è stato eseguito da operatori senza tanta esperienza (studenti), indipendentemente dalla localizzazione, dimensione e tempo dell’avvenuta perforazione. Keywords: Iatrogenic perforation, Acidic environnement, Bioactivity, Biodentine, Single visit, Parole chiave: Perforazione iatrogena, Ambiente acido, Bioattività, Biodentine, Singola visit

Microscopic and Chemical Assessments of the Filling Ability in Oval-Shaped Root Canals Using Two Different Carrier-Based Filling Techniques

Objectives: The aim of this study was to assess the filling ability in oval-shaped canals using two different carrier-based filling techniques. Materials and methods: Twenty-four human mandibular premolars with one oval canal were selected. Canals were shaped using WaveOne Gold Primary and ProGlider. Samples were divided into two groups and filled as follows: Thermafil and GuttaCore. The proportions of gutta-percha-filled areas (GPFAs), sealer-filled areas (SFAs), and void areas (VA), at 2 and 5 mm, were analyzed using optical numeric microscope, scanning electron microscope, and energy-dispersive X-ray. Statistical analysis: Data were compared by Kruskal-Wallis one-way analysis of variance on ranks, with statistical significance set at α = 0.05. Results: At 2 and 5 mm distances from the apex, this study discloses no statistically different filling ability for the two techniques. Concerning each sample treated using both filling systems, the presence of tags was visualized. At working length (WL)-5, and WL-2, the maximum tag penetration depth for the GuttaCore group into the dentinal tubules was, respectively, 96 μm and 48 μm, whereas the values in the thermafil group were 109 μm, and 55 μm, respectively. Conclusions: Our results clearly show that Thermafil and GuttaCore can fill oval-shaped canals in appropriate way. Furthermore, we can state that the GuttaCore obturator allows to preserve the same filling ability than Thermafil obturator, in view of the fact that there was no difference, in terms of GPFA, SFA, and VA between the two different carrier-based obturation technique

Microscopic and chemical evaluation of the filling quality of five obturation techniques in oval-shaped root canals

International audienceObjectivesThe aim of this study was to assess the filling quality of five obturation techniques in oval-shaped root canals.Materials and methodsA total of 212 mandibular first molars with one distal oval canal were selected. Distal canals, shaped with WaveOne Gold Primary, were randomly divided in five groups (n = 40) for obturation: continuous wave condensation, GuttaCore, Thermafil, single cone with AH plus, and single cone with BioRoot RCS. The proportions of gutta-percha-filled areas (GPFA), sealer-filled areas (SFA), void areas (VA), and the sealer/gutta tags into dentinal tubules at 4 mm and 2 mm from the apex were analyzed by an optical numeric microscope, SEM, and energy-dispersive X-ray (EDX). Data were then compared by Kruskal-Wallis one-way ANOVA on ranks (α = 0.05).ResultsAt 4 mm, a statistically significant higher GPFA and lower SFA were observed in the GuttaCore and Thermafil groups compared with the 3 other groups. A statistically significant lower VA was observed in the continuous wave condensation, GuttaCore, and Thermafil groups than in the two single-cone groups. At 2 mm, there were a statistically significant higher GPFA and lower SFA and VA in GuttaCore and Thermafil groups than in the 3 other groups. At the two levels investigated, the presence of gutta-percha tags was clearly demonstrated for GuttaCore and Thermafil groups; no tags were observed in the 3 other groups.ConclusionsObturation quality was overall improved in GuttaCore and Thermafil groups.Clinical relevanceCarrier-based techniques may significantly improve the filling quality compared to continuous wave condensation and single-cone technique. The single-cone technique might have inherent limitations especially in oval root canals regardless of the sealer used

Special Issue “Recent Advances in Biomaterials and Dental Disease” Part I

Oral cavities provide an entry point for food and nutrients [...