Development of clobetasol-loaded biodegradable nanoparticles as an endodontic intracanal medicament.

AIM: The aim of current study is the development and optimization of biodegradable polymeric nanoparticles (NPs) to be used in the field of Endodontics as intracanal medication in cases of avulsed teeth with extended extra-oral time, utilizing PLGA polymers loaded with the anti-inflammatory drug clobetasol propionate (CP). METHODOLOGY: CP-loaded nanoparticles (CP-NPs) were prepared using the solvent displacement method. CP release profile from CP-NPs was assessed for 48 h against free CP. Using extracted human teeth, the degree of infiltration inside the dentinal tubules was studied for both CP-NPs and CP. The anti-inflammatory capacity of CP-NPs was evaluated in vitro measuring their response and reaction against inflammatory cells, in particular against macrophages. The enzyme-linked immunosorbent assay (ELISA) was used to examine the cytokine release of IL-1ß and TNF-α. RESULTS: Optimized CP-NPs displayed an average size below 200 nm and a monomodal population. Additionally, spherical morphology and non-aggregation of CP-NPs were confirmed by transmission electron microscopy. Interaction studies showed that CP was encapsulated inside the NPs and no covalent bonds were formed. Moreover, CP-NPs exhibited a prolonged and steady release with only 21% of the encapsulated CP released after 48 h. Using confocal laser scanning microscopy, it was observed that CP-NPs were able to display enhanced penetration into the dentinal tubules. Neither the release of TNF-α nor IL-1ß increased in CP-NPs compared to the LPS control, displaying results similar and even less than the TCP after 48 h. Moreover, IL-1ß release in LPS-stimulated cells, decreased when macrophages were treated with CP-NPs. CONCLUSIONS: In the present work, CP-NPs were prepared, optimized and characterized displaying significant increase in the degree of infiltration inside the dentinal tubules against CP and were able to significantly reduce TNF-α release. Therefore, CP-NPs constitute a promising therapy for the treatment of avulsed teeth with extended extra-oral time.

Calcium hydroxide-loaded PLGA biodegradable nanoparticles as an intracanal medicament.

AIM: To develop a formulation in which calcium hydroxide (Ca(OH)2) was successfully loaded into poly(lactic-co-glycolic acid) (PLGA) biodegradable nanoparticles (NPs) to be used in the field of endodontics as an intracanal medicament, including NP optimization and characterization, plus drug release profile of the NPs compared with free Ca(OH)2. Additionally, the depth and area of penetration of the NPs inside the dentinal tubules of extracted teeth were compared with those of the free Ca(OH)2. METHODOLOGY: Ca(OH)2 NPs were prepared using the solvent displacement method. NPs was optimized with a central composite design to obtain a final optimized formulation. The morphology of the NPs was examined under transmission electron microscopy (TEM), and characterization was carried out using X-ray diffraction (XRD), Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC). The drug release profile of the Ca(OH)2 NPs and free Ca(OH)2 was evaluated up to 48 h. Finally, the depth and area of penetration inside the dentinal tubules of extracted teeth were examined for both the Ca(OH)2 NPs and free Ca(OH)2 using the Mann-Whitney U test to determine any significant differences. RESULTS: Utilizing the optimized formulation, the Ca(OH)2 NPs had an average size below 200 nm and polydispersity index lower than 0.2, along with a highly negative zeta potential and suitable entrapment efficiency percentage. The spherical morphology of the Ca(OH)2 NPs was confirmed using TEM. The results of the XRD, FTIR and DSC revealed no interactions and confirmed that the drug was encapsulated inside the NPs. The drug release profile of the Ca(OH)2 NPs exhibited a prolonged steady release that remained stable up to 48 h with higher concentrations than the free Ca(OH)2. After examination by confocal laser scanning microscopy, Ca(OH)2 NPs had a significantly greater depth and area of penetration inside dentinal tubules compared with the free drug. CONCLUSIONS: Ca(OH)2-loaded PLGA NPs were successfully optimized and characterized. The NPs exhibited a prolonged drug release profile and superior penetration inside dentinal tubules of extracted teeth when compared to Ca(OH)2 .

Successful Root Canal Treatment of an Atypical Mandibular Canine with a Boomerang-shaped Root and Canal System with a Large Periapical lesion-A Case Report with 9-year Follow-up.

AIM: This report describes an atypical mandibular canine with a single boomerang-shaped root and root canal system with a large periapical lesion managed by root canal treatment. METHODS: The chief complaint of a 16-year-old male was acute pain and an abnormal sensation in the right mandibular canine (tooth #27). The clinical examination revealed that tooth #27 had an unusual coronal morphology. The buccal aspect of the tooth resembled that of a normal canine but was significantly broader than expected. On the lingual aspect of the crown; however, there was an unusual cusp-like structure with ridges that was slightly less prominent than the buccal incisal tip. The intraoral periapical radiographs revealed a complex root with an obvious cow horn-shaped canal mesially and distally, but with the suggestion of a root structure joining the mesial and distal extensions. A large periapical lesion was present. Computed tomography revealed the presence of a single root and canal system shaped like a boomerang. Root canal treatment was performed and the patient was followed-up for 9 years. RESULTS: Following root canal treatment, the patient had no symptoms, no mobility, no periodontal pockets, or root resorption. At 9 years, the cone beam computed tomography images confirmed that satisfactory healing of the periapical tissues had occurred. CONCLUSION: The mandibular right canine had a unique boomerang-shaped root and canal system. Effective shaping and cleaning of the complex canal shape plus thermoplastic root filling aided the successful healing of the periapical lesion.

Nanoparticles in Endodontics Disinfection: State of the Art.

Endodontic-related diseases constitute the fourth most expensive pathologies in industrialized countries. Specifically, endodontics is the part of dentistry focused on treating disorders of the dental pulp and its consequences. In order to treat these problems, especially endodontic infections, dental barriers and complex root canal anatomy should be overcome. This constitutes an unmet medical need since the rate of successful disinfection with the currently marketed drugs is around 85%. Therefore, nanoparticles constitute a suitable alternative in order to deliver active compounds effectively to the target site, increasing their therapeutic efficacy. Therefore, in the present review, an overview of dental anatomy and the barriers that should be overcome for effective disinfection will be summarized. In addition, the versatility of nanoparticles for drug delivery and their specific uses in dentistry are comprehensively discussed. Finally, the latest findings, potential applications and state of the art nanoparticles with special emphasis on biodegradable nanoparticles used for endodontic disinfection are also reviewed.

Micro-computed Tomographic Assessment and Comparative Study of the Shaping Ability of 6 Nickel-Titanium Files: An In Vitro Study.

INTRODUCTION: This research studies and compares the shaping ability of WaveOne Gold (WG; Dentsply Tulsa Dental Specialties, Tulsa, OK), the Reciproc Blue (RB; VDW, Munich, Germany), TRUShape (TS, Dentsply Tulsa Dental Specialties), XP-endo Shaper (XP; FKG, La Chaux-de-Fonds, Switzerland), iRace (IR, FKG), and TruNatomy (TN; Dentsply Sirona, Ballaigues, Switzerland) in the preparation of moderately curved canals and using micro-computed tomographic technology. METHODS: Sixty lower molars with 2 mesial canals were randomly distributed into 6 groups of 10 molars and 20 canals per group (n = 20). Specimens were scanned before and after preparation using the SkyScan 1275 (Bruker microCT, Kontich, Belgium). Group 1 was treated with WG, group 2 with RB, group 3 with TS, group 4 with XP, group 5 with IR, and group 6 with TN. After instrumentation, researchers quantified the changes produced in the canal geometry in terms of surface, volume, structure thickness, surface convexity index, structure model index, percentage of surface touched, and centroids. Wilcoxon and analysis of variance tests were performed to compare the values before and after preparation and the differences between groups. The significance level was established at 5%. RESULTS: There were no significant differences between WG and RB (P > .05) and between TN and XP (P > .05). TN had significant differences with WG, RB, TS, and IR (P < .05). All the files produced similar apical transportation (P > .05). CONCLUSIONS: WG and RB and TN and XP had similar shaping effectivity. TS and WG touched the highest percentages of canal surfaces (81% and 73%, respectively) but produced the biggest changes in the canal anatomy. TN and XP better kept the canal anatomy, but TN touched the lowest percentage of canal surface (50%). All the files used were able to clean and to shape moderately curved canals with minimal apical transportation.

Cone-beam Computed Tomographic Analysis to Detect the Association between Primary and Secondary Endodontic Infections and Mucosal Thickness of Maxillary Sinus.

INTRODUCTION: This retrospective study used cone-beam computed tomographic (CBCT) imaging to evaluate the differences in the mucosal thickness of the Schneiderian membrane in primary and secondary endodontic lesions. METHODS: A total of 121 CBCT scans were analyzed. Clinical features such as sex, age, size and volume of the periapical lesion, dimension of the bone, morphology, and relationship between the roots and the mucosal thickness were recorded and analyzed in primary and secondary endodontic lesions in CBCT sagittal and coronal planes. Data were analyzed using the chi-square test, the Mann-Whitney U test, and multiple logistic regression (P < .05). RESULTS: Statistical analysis revealed no significant differences in membrane thickness between the primary and secondary lesions in the sagittal and coronal planes (P = .08 and .06). Differences between age groups were statistically significant in both groups (P < .05). The volume of the periapical lesions of the secondary endodontic lesions were statistically greater than that of the primary lesions (P < .05). Mucosal thickness prevalence increased when the volume of the lesion was greater, and the bone dimension was narrower in maxillary second premolars and first and second molars. Teeth with 2 or more affected roots were directly related to increased sinus mucosa thickening. CONCLUSIONS: CBCT images showed no differences in mucosal thickening between primary and secondary endodontic lesions.

TRUShape Versus XP-endo Shaper: A Micro-computed Tomographic Assessment and Comparative Study of the Shaping Ability-An In Vitro Study.

INTRODUCTION: The aim of this study was to evaluate and compare the shaping ability of XP-endo Shaper (XP; FKG Dentaire, La Chaux-de-Fonds, Switzerland) and TRUShape (TS; Dentsply/Tulsa Dental Specialties, Tulsa, OK) during the preparation of moderated curved root canals using micro-computed tomographic imaging. METHODS: Twenty human maxillary premolars with 2 roots were randomly separated into 2 groups of 10 teeth, which were scanned before and after root canal preparation using the SkyScan 1275 X-ray microtomograph (Bruker micro-CT, Kontich, Belgium) at a nominal resolution of <4 µm. Premolars and irrigant were maintained at 37° before and during preparation; group 1 was treated using XP and group 2 with TS. After preparation, researchers measured the amount of dentin removed, untreated superficies of canal walls, root canal volume, degree of canal transportation, and centering ability. Values of central tendency and dispersion were calculated using Statgraphics Centurion XV software (StatPoint Technologies, Inc, Warrenton, VA); means and median were compared using the Mann-Whitney-Wilcoxon test. The level of significance was set at 5% (P < .05). RESULTS: No significant statistical differences were observed between the 2 groups in shaping ability, untreated superficies of canal walls, degree of canal transportation, and centering ability (P > .05). CONCLUSIONS: Instrumentation of moderately curved root canals using the XP single file and the TS file system were equally effective. XP and TS maintained the original anatomy of the root canals and showed a similar percentage of untreated canal walls, centered ability, and minimal apical transportation.

Outcome of Autotransplantation of Mature Third Molars Using 3-dimensional-printed Guiding Templates and Donor Tooth Replicas.

Autotransplantation exhibits a number of advantages compared with other treatment options (ie, dental implants or fixed partial prostheses), such as greater resistance to occlusal loading, maintenance of the periodontal ligament and surrounding bone, and the potential for better esthetics. The aim of this study was to determine clinical outcomes for autotransplanted teeth with complete root formation using 3-dimensional-printed guiding templates and tooth replicas. Twenty-seven third molars with completely formed roots were autotransplanted. Each donor tooth and recipient site were examined clinically and radiographically (periapical radiographs). A selective cone-beam computed tomographic scan was taken of each donor tooth and recipient site. The images of the selected donor teeth were segmented and saved as stereolithography files. Similar to virtual planning of dental implants, correct angulation, rotation, and accurate positioning of the donor teeth were predefined using the stereolithography files. According to the virtually defined positions and dimensions of the donor teeth, 3-dimensional guiding templates and donor tooth replicas were printed. All autotransplantations were performed according to 1 treatment protocol and surgical technique. In 22 of the 24 transplanted teeth, no inflammation occurred during the healing period. At 2 years, no pathologic radiolucency or tooth resorption was observed in the 22 donor teeth. The autotransplanted teeth fulfilled the success criteria in 22 cases for a 91.7% success rate. Digital planning could potentially provide an accurate alternative to current autotransplantation techniques.

Danger zone analysis using cone beam computed tomography after apical enlargement with K3 and K3XF in a manikin model.

BACKGROUND: The objective of the study was to evaluate and compare how apical enlargement with K3 and K3XF nickel-titanium (NiTi) rotary instruments reduces the root thickness in the danger zone and affects canal transportation and centering ability in mandibular molar mesial canals in a manikin extracted tooth model. MATERIAL AND METHODS: Seventy-two mesial root canals of first mandibular molars were instrumented. Initial and post-instrumentation Cone Beam Computed Tomography scans were performed after root canal preparation up to size 25, 30, 35 and 40 files. Canal transportation, canal centering and remaining root dentin thickness toward the danger zone were calculated in sections 1, 2 and 3 mm under the furcation level. Data were analyzed using non-parametric Kruskal-Wallis analysis of variance at a significance level of P < 0.05. RESULTS: K3 instruments removed more dentin toward the danger zone compared with K3XF instruments (P< .05) and significant differences in dentin thickness were found when canal enlargement was performed to a #35-40 with both systems (P< 0.05). No significant differences in canal transportation and centering ability were found between systems, except when canal enlargement was performed to a #40 (P = 0,0136). No differences were observed when comparing the number of uses in both systems (P> 0.05). CONCLUSIONS: Under the conditions of this study K3 removed a significant amount of dentin at the furcation level compared with the R-Phase K3XF rotary system in curved root canals. Enlargement to a 35-40/04 file removed significantly more dentin with both systems. Key words:K3, K3XF, R-phase, center ability, canal transportation, dentin thickness, increased apical enlargement, danger zone, dentin thickness.

Lesión endo-periodontal: curación a tres años / Endo-periodontal lesion: a 3-year healing process

Las lesiones endo-periodontales pueden suponer un reto en el diagnóstico. Las imágenes radiolúcidas de furca acompañadas de sondajes profundos y aislados son compatibles con fracturas verticales, perforaciones o causas puramente endodónticas, es decir, abscesos periapicales crónicos con exacerbación por el surco gingival. Las perforaciones son complicaciones que afectan al pronóstico de la endodoncia y que desencadenan defectos periodontales. En el presente caso clínico se describe el retratamiento ortógrado con el sellado de una perforación en el tercio coronal de un primer molar inferior. Después de tres años de control, se observa curación radiográfica de ambas lesiones y una reducción de 6 mm en el sondaje periodontal

Diagnosis of endo-periodontal lesion can be challenging. Furcal radiolucencies accompanied with deep and isolated probings are compatible with vertical root fractures, perforations or with endodontic causes, that is to say, chronic periapical abscess exacerbated through the gingival sulcus.Perforations are complications that affect the prognosis of the root canal treatment and induce periodontal defects. The present case describes an orthograde root canal retreatment with a perforation sealing in the coronal third of a first lower molar. Three years after, a radiographic healing of both lesions and a reduction of 6mm periodontal probing is observed

Manejo conservador no quirúrgico de una reabsorción cervical invasiva tipo IV utilizando Biodentine / Nonsurgical conservative management of a class IV invasive cervical resorption using Biodentine

La reabsorción cervical invasiva (RCI) es una entidad poco frecuente de carácter agresivo que causa la destrucción de los tejidos dentales si no se trata. El diagnóstico de la RCI es complejo y de acuerdo a la literatura presente, en estadíos muy avanzados el tratamiento no es predecible, lo que conlleva la extracción del diente. Actualmente, gracias al avance de nuevas tecnologías para el radiodiagnóstico como la tomografía computerizada de haz cónico (CBCT), el microscopio dental, así como la introducción de nuevos materiales como el Agregado Trióxido Mineral (MTA(R)) el enfoque de este tratamiento y el pronóstico en estos casos puede mejorar. Recientemente, se ha introducido el Biodentine(R), un cemento biocerámico, como material sustitutivo del MTA(R) con claras ventajas sobre este como un menor tiempo de fraguado, que no presenta discoloración y unas propiedades mecánicas similares a la dentina. A continuación se presenta un caso de reabsorción cervical invasiva tratada con Biodentine® con controles clínicos, radiográficos y mediante CBCT a 6 meses

Invasive cervical resorption (ICR) is an uncommon but aggresive entity that cause the destruction of dental tissues if left untreaten. The diagnosis of ICR is complex and according to the literature, the treatment in advanced cases is not predictable, which can ultimately lead to extraction of the tooth. The current development of innovative technologies such as the cone-beam computed tomography (CBCT) and the dental operating microscope, as well as new materials such as mineral trioxide aggregate (MTA(R)) can facilitate improvements in the treatment approach and the prognosis of ICR. Recently, BiodentineTM, a new bioceramic cement, has been introduced as a substitutive material for MTA(R) with several advantages related to setting time, the elimination of discoloration and similar mechanic properties as dentine. A case of ICR is presented in which the management of the lesion using Biodentine is reported along with the clinical, radiographic and 6-month CBCT follow-up