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To determine the effectiveness of palatal brushing in the treatment of denture-related erythematous stomatitis (DES) in complete denture wearers.This two-parallel-arm RCT was conducted in three university clinics in Brazil, Canada, and Chile. Participants (n=77) were randomly allocated to receive (i) instructions for palatal brushing and standard oral/denture hygiene ("intervention"); or (ii) standard oral/denture hygiene instructions only ("control"). Data collection was carried out at the baseline and at 3 and 6 months after intervention. Outcomes included the magnitude of oral Candida carriage and the degree of inflammation of denture-bearing tissues. Groups were compared using generalized estimating equations and chi-square test (α=0.05).Palatal inflammation levels were reduced significantly in the "intervention" compared to "control" group at 6 months (intervention: 70%, control: 40%; chi-square, p=0.04). There was no between-group significant difference in the Candida count from denture and palatal biofilms; however, a subgroup analysis restricted to baseline Candida carriers showed further reduction with the intervention at 6 months. No adversity was observed by trialist or reported by participants.Including palatal brushing in oral instructions for denture wearers has positive impact on DES-related mucosal inflammation. Thus, our findings endorse the inclusion of palatal brushing in standard oral hygiene instructions to treat DES.

Titanium (Ti) alloys used for narrow dental implants usually contain aluminum (Al) and vanadium (V) for improved resistance. However, those elements are linked to possible cytotoxic effects. Thus, this study evaluated the biomechanical behavior of narrow dental implants made with Al- and V-free Ti alloys by the finite element method. A virtual model of a partially edentulous maxilla received single implants (diameter: 2.7 and 2.9 mm; length: 10 mm) at the upper lateral incisor area, with respective abutments and porcelain-fused-to-metal crowns. Simulations were performed for each implant diameter and the following eight alloys (and elastic moduli): (1) Ti–6Al–4V (control; 110 GPa), (2) Ti–35Nb–5Sn–6Mo–3Zr (85 GPa), (3) Ti–13Nb–13Zr (77 GPa), (4) Ti–15Zr (113 GPa), (5) Ti–8Fe–5Ta (120 GPa), (6) Ti–26.88Fe–4Ta (175 GPa), (7) TNTZ–2Fe–0.4O (107 GPa), and (8) TNTZ–2Fe–0.7O (109 GPa). The implants received a labially directed total static load of 100 N at a 45° angle relative to their long axis. Parameters for analysis included the maximum and minimum principal stresses for bone, and von Mises equivalent stress for implants and abutments. Ti–26.88Fe–4Ta reaches the lowest maximum (57 MPa) and minimum (125 MPa) principal stress values, whereas Ti–35Nb–5Sn–6Mo–3Zr (183 MPa) and Ti–13Nb–13Zr (191 MPa) models result in the highest principal stresses (the 2.7 mm model surpasses the threshold for bone overload). Implant diameters affect von Mises stresses more than the constituent alloys. It can be concluded that the narrow implants made of the Ti–26.88Fe–4Ta alloy have the most favorable biomechanical behavior, mostly by mitigating stress on peri-implant bone.

Single-implant overdentures (SIOs) represent a major biomechanical challenge in terms of prosthetic retention. The Novaloc attachment system has the potential to overcome those challenges when used for SIOs, due to the use of PEEK matrices. This study compared the retentive force of the Novaloc attachment to the traditional Locator system, before and after cyclic insertion–removal cycles. Three Novaloc matrices (white, yellow, and green, corresponding to low, medium, and high retention, respectively) and Locator (medium retention) were tested, totalling four groups. Retentive force was measured using an Imada force gauge before and after 1095 insertion–removal cycles, corresponding to a year of SIO wearing. Retention was tested with the implants angulated at 0, 10, and 20°. Data for the different groups, angles, and cycling periods were tested via linear regression analysis and two-way ANOVA (α = 0.05). Although the Locator system yielded higher retention forces in general, it lost a much higher percentage of retention with cycling. This trend was similar with the three angles, with forces being inversely proportional to the implant angulation. The authors conclude that Novaloc may provide more reliable retention for SIOs due to their higher resistance to insertion–removal cycling.

The aim of this study was to report the 40-month clinical radiographical outcomes of maxillary sinus floor augmentation using leukocyte-platelet rich fibrin (L-PRF) as a single graft in combination with immediately placed implants. Twenty partially edentulous individuals with missing teeth in the region associated to maxillary sinus were included in this retrospective study. A lateral sinus floor elevation was performed considering a complete wear of the bone wall of the maxillary sinus and immediately placing the implant and filled the maxillary sinus with L-PRF clots as a single graft. After 5 months, all the implants received single screwed implant-supported prostheses. Subsequent evaluation was every 4 months assessing the success rate and biological complications. Two maxillary sinus membrane were perforated and covered with L-PRF clots. The mean bone height gain was 62.6%, observing a 100% of success and that in all the cases achieved at least the implant height. In conclusion, the use of platelet-rich fibrin clot as a single graft biomaterial during the maxillary sinus lift procedure combined with immediate implant placement may be a reliable clinical alternative, even to repair the sinus membrane.

The success of dental implants is related to the amount, quality, and composition of the alveolar bone. The placement of platelet-rich fibrin (PRF) clot associated with a resorbable collagen membrane (RCM) in a postextraction alveolus is a technique used for ridge preservation. This case report study analyzed the ultrastructural characteristics of cross-sectioned alveolar bone that received PRF and RCM using scanning electron microscopy and the inorganic composition using "energy dispersive X-ray spectrometry," in order to explore the feasibility of this method to clinical studies. Three alveolar bone samples from two male patients (37 and 58 years old), obtained in the procedure of placing the dental implant, were analyzed. Two bone samples previously received PRF and RCM (M37 and M58), the third sample represented a physiological bone formation without treatment (M37-control). The bone sample M37 showed irregularly shaped islets of calcified material intermingled with connective tissue. The other samples, from the 58-year-old patient with PRF and RCM (M58); and the other untreated bone sample from the same 37-year-old patient (M37-control) showed similar ultrastructural morphology with trabecular conformation without islets agglomerations. The inorganic composition analysis showed higher concentrations of calcium and phosphorus in both samples treated with PRF and RCM in comparison to the untreated bone sample. The Ca/P ratio was higher in the M37 sample compared to the others samples. The results showed morphology and inorganic composition differences among the treatments used, suggesting that this method is feasible to analyze parameters of the alveolar bone tissue.

Statement of problem Extra-short implants in the posterior mandible can increase the functional surface area and reduce the risk of implant overload. However, reports of treatment using single extra-short implants in the posterior mandible with a midterm follow-up are lacking. Purpose The purpose of this prospective pilot study was to evaluate the clinical behavior of single extra-short 4-mm implants placed in the posterior mandible during a follow-up of 3 years from implant restoration. Material and methods A total of 18 participants with a single extra-short 4-mm-long implant placed in the area of the mandibular first molars participated in this pilot study. The survival and success rates of implants, as well as biologic and prosthetic variables, were evaluated during a follow-up of 3 years from implant restoration. Results The survival rate of the implants was 100%, with no implant or biologic complications recorded. One prosthetic complication (loosening of 1 screw) was observed. Conclusions Single extra-short (4 mm) implants in the posterior mandible showed favorable clinical behavior during the first 3-years of follow-up.

SUMMARY: It is critical to know the precise location and configuration of the mandibular canal (MC) to avoid damages in the alveolar inferior nerve during an invasive dental treatment. The aim of this study was to provide anatomic relationships of the mandibular canal in its entire pathway related to cortical walls and dental roots to serve as basic knowledge for dental clinical procedures performed in this area. We analyzed 50 CBCT images assessing the specific location of MC at the retromolar space as related to inferior teeth roots. Data were analyzed by side using descriptive statistics (median: mean [M], standard deviation [SD], 95 % confidence interval: lower endpoint [IC] and upper endpoint [IC’]). The MC length and pathway were measured from the mandibular foramen up to the mental foramen. MC was closer from lingual cortical than buccal at the retromolar space as well the distal root of the second molar and the root of the second premolar are closest to MC. A mean length for the MC of 70.8 (±5.3 mm) for the right side and 71 (±5.8 mm) for the left side were observed. In conclusion, it is critical for clinicians to know three-dimensionally the topographic relationships between the inferior teeth roots and the mandibular canal before proceeding to any invasive dental or surgical procedure at this region.

The objective of this study was to evaluate three energy densities of low-level laser therapy (LLLT, GaAlAs, 780 nm, 40 mW, 0.04 cm2) for the treatment of lesions to peripheral nerves using the sciatic nerve of rats injured via crushing model (15 kgf, 5.2 MPa). Thirty Wistar rats (♂, 200–250 g) were divided into five groups (n = 6): C—control, not injured, and irradiated; L0—injured nerve without irradiation; L4—injured nerve irradiated with LLLT 4 J/cm2 (0.16 J); L10—injured nerve irradiated with LLLT 10 J/cm2 (0.4 J); and L50—injured nerve irradiated with LLLT 50 J/cm2 (2 J). The animals were sacrificed 2 weeks after the injury via perfusion with glutaraldehyde (2.5%, 0.1 M sodium cacodylate buffer). The nerve tissue was embedded in historesin, cut (3 μm), mounted on slides, and stained (Sudan black and neutral red). The morphological and quantitative analysis (myelin and blood capillary densities) and morphometric parameters (maximum and minimum diameters of nerve fibers, axon diameter, G-ratio, myelin sheath thickness) were assessed using the ImageJ software. ANOVA (parametric) or Kruskal-Wallis (nonparametric) tests were used for the statistical analysis. Groups L0, L4, L10, and L50 exhibited diminished values of all the quantitative and morphometric parameters in comparison to the control group. The morphological, quantitative, and morphometric data revealed improvement after injury in groups L4, L10, and L50 (irradiated groups) compared to the injured-only group (L0); the best results, in general, were observed for the L10 group after 15 days of nerve injury.

SUMMARY: The allografts were used to obtain sufficient alveolar bone tissue for proper dental implant placement. The objective of the present study was to evaluate the morphological and quantitative characteristics (cellular and collagen densities) of the newly formed alveolar bone with the application of cortical bone (CB) and demineralized bone matrix (DBM) allografts. Six samples of alveolar bone tissue from 5 patients (50 ± 6.3 years) were obtained after 6 months of application of the allografts and immediately before the placement of the dental implants. The samples were fixed (buffered formaldehyde, pH7.2), decalcified (EDTA 10 %) and histologically processed (HE and Picro-Sirius) for histologic analysis. Morphological analysis revealed presence of osteocytes and trabeculae in neoformed bone tissue near the allografts and absence of inflammatory and allergic cells; the remnants of CB were located mainly in the periphery of the bone tissue and the remnants of DBM were more incorporated into the tissue. Osteogenitor cells were observed around the remaining material. The cell density was not modified in newly formed bone tissue with the application of both allografts as compared to mature bone tissue. The density of the type I and III collagens present in the osteoids interspersed with the remainder of the materials showed a tendency to increase in the samples treated with DBM. It was concluded that by the histological characteristics observed both grafts were biocompatible, however the bone treated with DBM presented better incorporation and a tendency of increase of the collagen content in the remnant region of the allografts.

Purpose To evaluate the biomechanical behaviors of different framework materials in implant-supported fixed mandibular prostheses using three-dimensional (3D) finite element analysis. Materials and methods A model of a severely resorbed edentulous mandible was obtained from a tomography database. Morse taper-connection implants and multi-unit abutments were cut with an electro-erosion machine and scanned using a 3D scanner. The implants were positioned on the model at the bone level and distributed equally to support a fixed complete prosthesis. The simulations were divided into six groups according to the framework material: titanium (Ti); cobalt-chromium (Co-Cr); zirconia (ZrO2); polyether ether ketone (PEEK); carbon fiber-reinforced polyether ether ketone (CFR-PEEK); and polymethyl methacrylate (PMMA). The resultant load applied was obtained from the masseter, temporal, lateral, and medial pterygoid muscles. The principal stresses and von Mises equivalent stresses were analyzed and compared among the framework materials, and the results were described both quantitatively and qualitatively. Results PEEK and PMMA frameworks showed the highest total deformation values, showing decreases of von Mises stresses in the frameworks, implants, and abutments, but with a high tensile stress in the trabecular bone that achieved critical values. CFR-PEEK frameworks achieved their failure limit, whereas the ZrO2, Co-Cr, and Ti frameworks exhibited principal stresses in the bone region within physiologic limits. Conclusion From a biomechanical point of view, the Ti, Co-Cr, and ZrO2 frameworks demonstrated the most favorable outcomes.

Aim To develop a new surgical model for sinus floor augmentation (SFA) in rabbit for experimental purposes. Materials and methods Eight adult rabbits were used, two for a surgical design using the anatomical dissection study, and the other six for an endoscopically assisted intraoral approach of SFA unilaterally, creating a subantral space where an allograft biomaterial was deposited. SFA was verified through cone-beam computerized tomography. Healing, weight, food, feces, and behavior were evaluated for 4 weeks post-operatively. Results All animals survived. There was no bleeding or infection; inflammation was mild. No changes were observed in terms of feeding, weight, feces, or behavior. Tissue healing was normal. Conclusion This model is a refinement of the experimental technique and is a real option for SFA, without compromising animal morbidity because of its conservative design. The minimally invasive approach with endoscopic assistance reduces bias and improves surgical predictability.

SUMMARY: The maxillary sinus floor location and the buccal bone plate are factors to be considered in the long-term success with implant treatments mainly in the premolar region. the aim of this study was to establish morphometric characteristics of the buccal cortical bone (BCB) thickness of maxillary premolars and its relation to maxillary sinus floor through CBCT. In this study 350 first and second maxillary premolars were analyzed from 110 CBCT images and the buccal cortical bone (BCB) was measured in a coronal view at the major axis level of each premolar. In addition, in 200 first and second maxillary premolars CBCT images were measured the distance from premolar apex to maxillary sinus floor (MSF) in both frontal and sagittal plane. The type of relationship between the apex and MSF was classified according to Ok et al. (2014). The second premolar was observed with higher values of BCB (p0.05). In second premolar, only significantly higher values were observed in the male sex in MA-MB-MC (p>0.05). Regarding to MSF and its relation to premolar roots, it was observed that 10 % of the sample was classified as type I, 19 % as type II, 55.5 % as type III and 15.5 % as type IV. The BCB of the upper premolar region is thicker in the apical region and decreases toward the coronal region. Almost 50 % of apex of second premolars are closely and risky related MSF (Type I and II).

This study aimed to describe the use of autologous fibrin glue (AFG) with a collagen carrier during maxillary sinus lift procedures with immediate implants during 3 years of follow-up. Twelve patients who had lost their teeth in the region associated to maxillary sinus, with a bone remnant 3 to 5 mm in height, were selected to perform a maxillary sinus augmentation with AFG and collagen membrane, placing the implant immediately. After 5 months, the implants were connected and rehabilitated. The patients were followed-up for a 3-year period, being evaluated every 6 months. At the end of the 3-year follow-up period, 100% implant success was observed, with a mean of bone augmentation of 7.75 mm. Three maxillary sinus membranes were perforated and healed by using AFG and collagen membrane without identify any complication during the follow-up period. Finally, the use of collagen carrier combined with AFG as a filling material during the maxillary sinus lift procedure may be a low-cost and reliable alternative that allows bone formation.

Cyanoacrylate adhesives have been used in medicine and dentistry with some controversial opinions. The aim of this review was to summarize the relevant literature regarding the use of cyanoacrylate adhesives for oral wounds during dental and surgical procedures, with focus on the applications, indications, advantages, and disadvantages. In conclusion, in vivo and clinical studies have demonstrated in the last few years convincing results regarding the safety, efficacy, ease of application, and feasibility of all types of cyanoacrylate adhesives used in intra- and extraoral procedures.

This practice-based study presents the clinical outcomes of a minimally invasive method for retrieving failed dental implants from elderly patients. Traditional removal methods for failed dental implants include trephination and other invasive procedures. That can be a special concern for the elderly, since aging exacerbates oral surgery-related morbidity and anxiety. This retrospective cohort study gathers data from 150 patients seen in a private clinic. Their implants (n = 199) failed due to biological, mechanical, or iatrogenic causes, and were removed as part of their treatment plan. Collected data included: (1) implant location (maxilla/mandible, anterior/posterior region), (2) reasons for implant retrieval, (3) connection type, (4) removal torque, and (5) operatory procedure—flapless and using a counter-torque removal kit, whenever possible. Flapless/minimally invasive retrieval was successful for 193 implants (97%). The remaining six implants demanded trephination (open-flap). The most common reasons for implant retrieval (81%) involved biological aspects, whereas iatrogenic (12%) and biomechanical (7%) reasons were less common. The surgical technique used was not associated to connection types or removal torque. Authors conclude that a counter-torque ratchet system is a minimally invasive technique with a high success rate in retrieving implants from elderly patients. Present findings support its use as a first-line approach for implant retrieval in that population.

Aim To evaluate the release of sodium hypochlorite from three different commercial brands of heat-polymerized acrylic resin immersed in water and submitted to mechanical or chemical polishing after disinfection with hypochlorite at different concentrations. Material and methods Fifty-four disk-shaped specimens (n = 18) were made for each resin (Lucitone 550, QC-20, and Classico) and assigned to two groups according to the type of polishing. Specimens were divided in three sub-groups in relation to sodium hypochlorite concentration (1%, 2.5%, and 5.25%), and the groups were immersed for 10-min periods in each sodium hypochlorite concentration. The electrochemical method used for detecting the release of sodium hypochlorite in each specimen was the cyclic voltammetry. Results In the specimens of Classico resin polished mechanically and immersed in 5.25% sodium hypochlorite, as well as Lucitone and QC-20 resins immersed in 2.5%, the amounts of disinfectant solution released in the four 15-min water exchanges were higher than the four 60-min exchanges. Conclusion There were differences in hypochlorite release from the three commercial brands of denture-base acrylic resins subjected to mechanical polishing. However, no hypochlorite release from the same resins was observed when they were subjected to chemical polishing.

Los cambios estructurales y morfologicos derivados de la hipermineralizacion dentinaria progresiva determina la adhesion a su superficie. Fue realizado un estudio planimetrico y el volumen de fractura estimado para evaluar la eficacia de resina compuesta adherida a dentina cervical hipermineralizada con y sin retenciones a traves de la prueba de cizalla. Treinta y cuatro premolares obtenidos de pacientes adultos fueron utilizados para obtener una superficie dentinaria cervical plana. Las muestras fueron distribuidas aleatoriamente en dos grupos: 1) experimental, donde se realizaron retenciones hemiesfericas a la dentina cervical, y 2) control, donde la dentina plana fue mantenida. Usando un dispositivo, una columna de resina fue construida en la superficie dentinaria y adaptada con adhesivos en las muestras de ambos grupos, las cuales fueron sometidas al test de cizalla. El analisis morfologico fue realizado con un microscopio mientras que el porcentaje de superficie remanente para cada componente del adhesivo fue calculado planimetricamente. El volumen del tejido perdido fue determinado utilizado el metodo de Scherle. En el estudio planimetrico, el promedio de resina remanente en la superficie fue significativamente mayor en el grupo experimental y con menos dentina intacta en el grupo control. El analisis volumetrico mostro una mayor perdida de sustrato dentinario en el grupo control. De esta manera, el uso de tecnicas morfometricas y volumetricas permite la evaluacion de la eficacia de una tecnica, demostrando que la inclusion de retenciones mecanicas en la dentina hipermineralizada cervical mejora las propiedades de adhesion.

Purpose: To evaluate the biomechanical behaviors of multiple implant-supported prostheses with different implant lengths, connections, locations, and restoration materials in the maxillary anterior region using three-dimensional finite element analysis. Materials and Methods: A finite element model of a maxillary image was created from a tomography data bank. The simulations were executed in two types of models based on the treatment plan: (1) two implants with 4.0-mm diameters placed in the maxillary central incisors to simulate an implant-supported fixed prosthesis with four elements with a cantilever of both maxillary lateral incisors; (2) two implants with 3.75-mm diameters placed in the maxillary lateral incisors to simulate a conventional fixed prosthesis with four elements with pontics for maxillary central incisors. Subsequently, the models created were subdivided into eight subgroups according to implant length, connection type, and restoration material. A total static oblique load of 150 N was applied to the cingulum area of the palatal surfaces of the four incisors at an angle of 45 degrees to the long axis of the implant in the palatal-labial direction. Bone stresses were analyzed through maximum and minimum principal stresses and ductile material as implant, framework, and abutments were analyzed using von Mises stress criterion. Results: Regardless of implant diameter and type of treatment, the 8.5-mm-long implants exhibited the lowest tensile and compressive stresses. Maximum and minimum principal stresses were identified in the cortical bone. The lowest von Mises equivalent stress values were identified in the metal-ceramic prostheses, with the exception of the cantilever prosthesis model with flat top connection. Conical cone implant models exhibited maximum von Mises equivalent stress in contact with the abutment. Conclusion: The lowest principal stresses in the peri-implant bone were observed in implants with conical cone connection and 8.5 mm in length. Also, in most cases, the models with metal-ceramic restorations exhibited better stress distributions.

The use of dental implants has been increasing in the last years, however, their chemical composition is an important issue due to the fact that the implant surface may suffer a corrosion process, allowing the possibility of ions being released and resulting in a possible biological response. Thus, the aim of this study was to evaluate the morphological analysis of the surface and chemical composition of different implant types through an energy-dispersive X-ray spectrometry (EDX) system. Eight dental implant models from different manufacturers were analyzed using variable pressure scanning electron microscopy (VP-SEM) and EDX. The chemical composition and general characteristics of the structural morphology in different dental implant surfaces were analyzed randomly. Nitrogen was identified in two samples, while zirconium was observed in only one model. Aluminium was identified in five samples ranging between 4% and 11% of its composition. Regarding the morphological characteristics, two samples from the same manufacturer had the most irregular surface designed to increase the contact surface, while the others revealed their surfaces with roughness at the micrometric level with no major irregularities. In conclusion, despite the morphology of implants being similar in most of the analyzed samples, more than 50% of them, which are brands of implants available on the market, showed aluminium on the implant surface. Finally, STR (Bone level, Roxolid), DENT (Superline) and NEO (Helix GM) could be considered, among the analyzed samples, the safest implants from the point of view that no aluminium was detected in their chemical composition.

This study analyzed the architecture of Platelet-Rich Fibrin (PRF) clots and assessed their elemental composition in order to provide new insight into this biomaterial. Five surplus PRF clots (2,700 RPM, 12 min.) donated by patients (63.6 ± 12.3 years old) were prepared for use in dental clinical procedures. The internal three-dimensional morphology of the red zones and the thirds of the yellow zones of the clots were analyzed by Variable Pressure Scanning Electron Microscope (VPSEM) after sample preparation by two methods: 1. Fixation (2.5% gluataraldehyde); and 2. Fixation with subsequent partial removal of extracellular elements (8 N, HCl). Semi-quantitative elemental analysis was performed by energy-dispersive X-ray spectrometry (EDX). VPSEM analysis showed erythrocytes in both the red zone and the yellow zone, which consisted mainly of fibrin. Removal of extracellular elements enriched the morphology of both zones; the organization of the fibrin was observed to differ in the thirds of the yellow zone, with increasing density and organization to distal. The elements that compose organic substances (C-Carbon, N-Nitrogen, O-Oxygen, Na-Sodium and P-Phosphorus) and halogens (Cl-Chloride and S-Sulfur) were detected; the highest concentrations were of C, followed by O (p 0.05), in the proximal region of the fibrin. The results of the present study suggest organization of fibrin in the PRF clot, and also reveal the distribution of the elements present in the different regions of the clot. Improved understanding of these characteristics may favor the use of this biomaterial by increasing its efficiency and functionality.

Introduction: The aim of this study was to evaluate the wear of ProTaper Next rotary files, X1, X2, and X3 after shaping 6, 10, and 14 maxillary molar vestibular canals. Materials and Methods: One hundred and sixty-two rotary files were divided into three groups according to the number of prepared canals, namely Group 1 (6 canals), Group 2 (10 canals), and Group 3 (14 canals). After canal preparation, files were embedded in resin molds, sectioned at 6 mm from the tip, and the wearied surface was microscopically evaluated. AutoCAD® software was used to measure the wear of edges in the different sections and multilevel mixed linear regression model to statistically analyze the data. Results: The files exhibited progressive wear as the number of uses increased. X2 and X3 files of Group 2 (10 canals) showed the highest wear, which decrease at 14 canals. Conclusions: X1, X2, and X3 files can shape until 10 canals without loss of their edge effectiveness.

The aim of this study was to analyze the influence of three different transmucosal heights of the abutments in single and multiple implant-supported prostheses through the finite element method. External hexagon implants, MicroUnit, and EsthetiCone abutments were scanned and placed in an edentulous maxillary model obtained from a tomography database. The simulations were divided into two groups: (1) one implant with 3.75 × 10 mm placed in the upper central incisor, simulating a single implant-supported fixed prosthesis with an EsthetiCone abutment; and (2) two implants with 3.75 × 10 mm placed in the upper lateral incisors with MicroUnit abutments, simulating a multiple implant-supported prosthesis. Subsequently, each group was subdivided into three models according to the transmucosal height (1, 2, and 3 mm). A static oblique load at an angle of 45 degrees to the long axis of the implant in palatal-buccal direction of 150 and 75 N was applied for multiple and single implant-supported prosthesis, respectively. The implants and abutments were assessed according to the equivalent Von Mises stress analyses while the bone and ceramics were analyzed through maximum and minimum principal stresses. The total deformation values increased in all models, while the transmucosal height was augmented. The transmucosal height of the abutments influences the stress values at the bone, ceramics, implants, and abutments of both the single and multiple implant-supported prostheses, with the transmucosal height of 1 mm showing the lowest stress values.

El proposito de este estudio fue evaluar mediante analisis de elementos finitos (FEA) la deformacion total o desplazamiento como un sistema completo de protesis multiples implanto-soportadas en la region anterior de la maxila con diferentes longitudes, conexiones y posiciones del implantes y variando el material de restauracion. Se utlizo un modelo hemi-maxilar de una region anterior desdentada de un modelo para ser analizado por medio de elementos finitos. Las simulaciones fueron divididas en dos grupos de acuerdo con el plan de tratamiento: 1) dos implantes se colocaron en los incisivos centrales superiores, simulando una protesis fija implanto-soportada (resina acrilica y metal-ceramica) de cuatro elementos con cantilever de ambos incisivos laterales superiores; 2) dos implantes colocados en los incisivos laterales superiores, simulando una protesis fija convencional de cuatro elementos con los dos incisivos centrales superiores como pontico. Los modelos con protesis en cantilever en resina acrilica mostraron los mayores valores de deformacion total, siendo 17 veces mayor a los de metal-ceramica en la cara distal de los incisivos laterales, independientemente del tipo de conexion del implante. En las protesis convencionales en resina acrilica, las conexiones hexagonales externas tenian valores deformacion total mas bajos en comparacion con la conexion cono morse. Tambien, se encontro que la longitud del implante no mostro ninguna influencia en los valores de la deformacion total. En conclusion, la deformacion total fue sustancialmente mayor en todos los modelos con restauraciones de resina acrilica.

La fuerza masticatoria máxima funcional (FMMF) se ha definido como la máxima fuerza generada entre los dientes maxilares y mandibulares. Así el objetivo de esta investigación fue de obtener datos reales sobre las FMMF a nivel molar, premolar, canino e incisivo en individuos adultos jóvenes. El estudio incluyó una muestra de 50 individuos entre 18 y 25 años de edad, totalmente dentados y con perfil esqueletal tipo I y clase I molar y canino. Se utilizó como instrumento un dispositivo de medición de fuerzas portátil, realizando las medidas en la región molar, premolar, canina e incisiva. A los individuos se les indicó morder el instrumento con la mayor fuerza posible, alternando las diferentes zonas a medir, aplicándose tres mediciones en cada diente y registrando el mayor valor en cada zona. La media de las fuerzas ejercidas del sexo masculino fue de 698, 516, 322 y 220 N, en las regiones molar, premolar, canina e incisiva, respectivamente. Por otro lado, en el sexo femenino se observaron valores medios de 466, 431, 232 y 174 N en las regiones molar, premolar, canina e incisiva, respectivamente. Se puede concluir que se observaron diferencias significativas de FMMF entre ambos sexos en las diferentes regiones, identificando los mayores valores en los individuos de sexo masculino en la región molar. Además, se identificaron diferencias significativas de la FMMF sólo en la región canina del sexo masculino al relacionarlas con el lado del arco.

La prevalencia de sexo y el padron de edad relacionado a los diferentes tipos de rehabilitaciones protesicas son variables importantes que deben ser estudiadas. De esta manera, el objetivo de este estudio fue evaluar el perfil de edad y genero en pacientes rehabilitados con protesis dentales en un curso de Odontologia durante un periodo de cinco anos. Fueron evaluados 638 fichas de pacientes que recibieron protesis parcial fija (PPF), protesis parcial removible (PPR) y protesis total (PT). Las protesis de los pacientes rehabilitados con PPR fueron clasificadas en dentomucosoportada (DM) o dentosoportadas (D). Para el analisis de los resultados, los pacientes fueron divididos en 2 grupos: A) ≥50 anos y B)

The aim of this study was to evaluate the corrosion resistance of pure titanium grade 4 (cp-Ti-4), subjected to disinfection with 0.2% and 2% peracetic acid during different immersion periods using anodic potentiodynamic polarization test in acid and neutral artificial saliva. Cylindrical samples of cp-Ti-4 (5 mm x 5 mm) were used to fabricate 24 working electrodes, which were mechanically polished and divided into eight groups (n=3) for disinfection in 2% and 0.2% peracetic acid for 30 and 120 min. After disinfection, anodic polarization was performed in artificial saliva with pH 4.8 and 6.8 to assess the electrochemical behavior of the electrodes. A conventional electrochemical cell, constituting a reference electrode, a platinum counter electrode, and the working electrode (cp-Ti specimens) were used with a scanning rate of 1 mV/s. Three curves were obtained for each working electrode, and corrosion was characterized by using scanning electron microscopy (SEM) and energy dispersive x-ray spectrometry (EDS). Data of corrosion potential (Ecorr) and passive current (Ipass) obtained by the polarization curves were analyzed statistically by Student's t-test (a=0.05). The statistical analysis showed no significant differences (p>0.05) between artificial saliva types at different concentrations and periods of disinfection, as well as between control and experimental groups. No surface changes were observed in all groups evaluated. In conclusion, disinfection with 0.2% and 2% peracetic acid concentrations did not cause corrosion in samples manufactured with cp-Ti-4.

Background. Regardless of the multiple options of connections, diameters and heights for dental implants, the clinician should know the biomechanical behavior of the bone to plan the treatment according to the biological and anatomical conditions of each patient, without risk to the long-term treatment success. Review. The following review attempts to summarize the relevant literature to establish guidelines for clinicians based on the scientific evidence regarding the influence by the implant’s connection, diameter and length on the bone biomechanics. Conclusions. The length, diameter and connection of each implant have a degree of influence in bone biomechanics. Despite the influence of different implant connections, diameters and lengths on peri-implant bone stress and strain, these characteristics should remain within the physiological limits to avoid a pathological overload, bone resorption and consequent risk to the long-term success of implant-prosthetic treatment.

The aim of this study was to quantify the cortical and cancellous bone in the mandibular symphysis and relate it to the teeth and to the skeletal class. A descriptive study was conducted using cone beam computerized tomography (CBCT). Class I and class III subjects were included, defined according to dental occlusion and cephalogram results. Linear measurements were taken on the CBCT of the mandibular canines, lateral incisors, and central incisors, where the analysis was related to the axial and apical axes considering the bone in relation to the dental area. With previous definitions, an observer took 2 measurements of the height of the mandibular symphysis, cortical bone of the buccal and lower region, and thickness of cancellous bone at different levels; the correlation coefficient between the first and second measurement was 0.99 and presented P = .001. The results were analyzed with analysis of variance and Tukey's honest significant difference test, with P < .05 being statistically significant. The symphysis height was significantly greater in class III subjects. The cortical bone was an average 1.67 ± 0.44 mm in vertical distance in the skeletal class I group and 1.74 ± 0.47 mm in the class III group. The cancellous bone had an average width of 5.03 ± 1.94 mm in the skeletal class I group and 4.74 ± 2.05 mm in the class III group. It was observed that cancellous bone was significantly thicker at the incisor level than at the canine level. There were anatomical differences between skeletal class I and class III subjects, although the clinical significance may be questionable. With the values from these analyses, it may be concluded that there are no significant differences in quantitation of the cortical and cancellous bone in the anterior mandibular symphysis.

Background Denture-related erythematous stomatitis (DES) is a chronic biofilm-mediated disease, affecting one in every three complete denture wearers. Antifungals are the treatment most commonly prescribed by oral health professionals, based on the belief that colonization by Candida spp. is the main cause of DES. However, high recurrence rates and adverse effects are commonly observed, prompting the need for practice guidelines regarding treatment. Results from our pilot study demonstrate that palatal brushing can reduce the palatal inflammation and potentially associated Candida carriage without any need for antifungal therapy. The objective of this study is to validate these pilot results by means of a randomized controlled trial (RCT) and provide a practice guideline for clinicians. Methods/design A pragmatic, two-parallel-arm, multicenter RCT will be conducted in Canada, Brazil, and Chile. Fifty-two adult complete denture wearers presenting with moderate to severe DES will be allocated randomly to two groups: the Intervention arm will consist of palatal brushing and standard oral and denture hygiene measures, while the Control arm will include only standard oral and denture hygiene measures. The study outcome will be the oral Candida carriage. Participants will be assessed at baseline, and at 3 and 6 months post intervention. Descriptive, bivariate, and mixed models with repeated measures will be performed following the intention-to-treat principle. Discussion This pragmatic RCT will serve to provide a clinical practice guideline regarding the use of preventive measures in the treatment of biofilm-mediated oral diseases. Moreover, it will have a great impact on reducing the harm of antifungal overtreatment on patients suffering from DES. Trial registration ClinicalTrials.gov, NCT02686632. Registered on 15 February 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1947-y) contains supplementary material, which is available to authorized users.

Background It is very important for a clinician to know the increased wear of mechanized files when establishing endodontic therapy. The aim of this study was to check the wear of the Primary WaveOne file upon shaping two, four and six maxillary molar vestibular canals. Material and Methods The deterioration of 40 files, divided into four groups, was evaluated microscopically: group 1, control (unused); group 2, two canals; group 3, four canals; and group 4, six canals. After instrumentation, the files were embedded in resin and sectioned at their apical third into three equal parts. To analyze the wear of edges in the different sections, AutoCAD software was used and analysis of variance (ANOVA) was then performed to compare the mean rake angles. Results The files with two and four uses showed slight wear, whereas those with six applications showed significant wear (p

El foramen mental (FM) es un referente anatomico importante durante procedimientos quirurgicos y colocacion de implantes. Con el proposito de conocer la detectabilidad y posicion del FM, caracterizandolo respecto a sus relaciones anatomicas, fueron analizadas 215 radiografias panoramicas convencionales. Ademas, se determino la presencia y extension del bucle del canal mandibular. El FM se detecto en el 87,9% de los casos, en mayor porcentaje en hombres y a menor edad. La posicion anteroposterior mas frecuente del FM fue en relacion al eje longitudinal del segundo premolar en el lado derecho y en el izquierdo entre los ejes longitudinales del primer y segundo premolar. La posicion supero-inferior mas frecuentemente observada en ambos sexos y todos los grupos etarios fue bajo el apice de los dientes. La distancia promedio desde el centro del FM a la linea mediana fue de 35,3 mm y 35,6 mm en el lado derecho e izquierdo, respectivamente. La distancia promedio desde el centro del FM al margen mandibular fue de 16,6 mm a la derecha y 17,1 mm a la izquierda. En relacion al bucle del canal mandibular, se detecto en un 33,9% de los casos y su extension fue de 5,3 mm y 4,8 mm en el lado derecho e izquierdo, respectivamente. Es fundamental conocer la anatomia, ubicacion de estructuras y evaluar esta zona previo a cualquier procedimiento quirurgico o colocacion de implantes dentales, para asi evitar lesiones del FM y nervio mental o el bucle del canal mandibular anterior o posterior y nervio alveolar inferior.

Las variaciones anatomicas de los canales radiculares juegan un papel importante en el exito del tratamiento endodontico, sobre todo en dientes con necrosis pulpar. Tradicionalmente, la preparacion de los canales radiculares se realizo con el uso de limas de acero inoxidable, pero en los ultimos anos, nuevos instrumentos flexibles se introdujeron para evitar o reducir al minimo errores o iatrogenias en la conformacion del sistema canalicular. Se ha propuesto el movimiento reciprocante como alternativa al movimiento de rotacion continua, con el fin de reducir el riesgo de fractura del instrumento y la deformacion del canal radicular. El objetivo de este articulo fue presentar un caso clinico que describe una forma sencilla de realizar el tratamiento endodontico de un premolar maxilar con tres canales radiculares utilizando el sistema reciprocante WaveOne.

The aim of this study was to determine the tensile strength of crowns cemented on metallic substrate with four different types of luting agents. Twenty human maxillary molars with similar diameters were selected and prepared to receive metallic core castings (Cu-Al). After cementation and preparation the cores were measured and the area of crown's portion was calculated. The teeth were divided into four groups based on the luting agent used to cement the crowns: zinc phosphate cement; glass ionomer cement; resin cement Rely X; and resin cement Panavia F. The teeth with the crowns cemented were subjected to thermocycling and later to the tensile strength test using universal testing machine with a load cell of 200 kgf and a crosshead speed of 0.5 mm/min. The load required to dislodge the crowns was recorded and converted to MPa/mm2. Data were subjected to Kruskal-Wallis analysis with a significance level of 1%. Panavia F showed significantly higher retention in core casts (3.067 MPa/mm2), when compared with the other cements. Rely X showed a mean retention value of 1.877 MPa/mm2 and the zinc phosphate cement with 1.155 MPa/mm2. Glass ionomer cement (0.884 MPa/mm2) exhibited the lowest tensile strength value. Crowns cemented with Panavia F on cast metallic posts and cores presented higher tensile strength. The glass ionomer cement showed the lowest tensile strength among all the cements studied.

La reabsorcion centripeta del maxilar es un proceso continuo despues de la perdida dentaria. Para el tratamiento de sitios oseos deficientes, se pueden utilizar injertos de hueso autologo; como alternativa, se puede aplicar biomateriales, que no requieren sitios donantes intra o extraorales. El presente reporte describe la utilizacion de barreras oclusivas y aloinjerto cortical particulado en defectos maxilares transversales. Este abordaje quirurgico fue realizado en cinco pacientes (4 mujeres y 1 hombre, de 20 hasta 37 anos de edad). Los resultados clinicos muestran que se formo suficiente tejido duro para permitir la rehabilitacion de implantes en los sitios de hueso insuficiente. La evaluacion histologica revelo pequenas cantidades de hueso neoformado con predominantes fibras colagenas y hueso maduro con muy pocos elementos celulares. Dependiendo de la situacion del sitio original, se puede aplicar un abordaje minimamente invasivo con barreras oclusivas y aloinjerto cortical particulado. Se pudo observar un aumento oseo promedio de 2,3, 2,7 y 2,9 mm para las regiones de la cresta osea, zona media y apical, respectivamente.

The effects of low-level laser therapy (LLLT) and natural latex protein (F1, Hevea brasiliensis) were evaluated on crush-type injuries (15kg) to the sciatic nerve in the expressions of nerve growth factor (NGF) and vascular endothelium growth factor (VEGF) and ultrastructural morphology to associate with previous morphometric data using the same protocol of injury and treatment. Thirty-six male rats were allocated into six experimental groups (n = 6): 1-Control; 2-Exposed nerve; 3-Injured nerve; 4-LLLT (15J/cm2, 780nm, 30mW, Continuous Wave) treated injured nerve; 5-F1 (0,1mg) treated injured nerve; and 6-LLLT&F1 treated injured nerve. Four or eight weeks after, sciatic nerve samples were processed for analysis. NGF expression were higher (p

Para validar los resultados virtuales de analisis por elementos finitos (FEA) es necesario que los modelos matematicos consideren el area de insercion muscular. Asi, el objetivo de este estudio fue medir el area de insercion en la mandibula de los musculos de masticacion en cadaveres humanos para ser utilizado en FEA. El area de insercion en la mandibula de los musculos de masticacion fue medida en ambos lados de cincuenta cadaveres humanos por medio de fotografias digitales y software. El area de insercion del musculo masetero fue 7,47(±0,41) cm2, la porcion interna del musculo temporal fue de 3,05(±0,13) cm2 y su porcion externa de 2,25(±0,28) cm2, para los musculos pterigoideo medial fue de 2,2(±0,23) cm2 y pterigoideo lateral 0,8(±0,05) cm2. En conclusion, los datos son suficientes para ser utilizados para analisis de elementos finitos.

espanolCon la finalidad de disminuir los errores durante la preparacion de los conductos radiculares, se han introducido diversas modificaciones en los sistemas de instrumentacion mecanizados de niquel-titanio. Se realizo un estudio in vitro para comparar el grado de transporte que se presenta a nivel de la union del tercio apical con el tercio medio de conductos radiculares con el sistema rotatorio Protaper Universal y el sistema manual de niquel-titanio, con la tecnica de fuerzas balanceadas. Se trabajo con 52 conductos mesiales de 26 molares maxilares y mandibulares, las cuales fueron divididas en dos grupos. El primer grupo de conductos (n = 28) fueron instrumentados con Protaper Universal rotatorio y el segundo grupo de conductos (n = 24) fueron instrumentados con tecnica manual de fuerzas balanceadas. Las raices mesiales de los molares fueron sumergidas en una matriz de acrilico, la cual permitio manipular las preparaciones, realizar cortes transversales y comparar los conductos radiculares antes y despues de la instrumentacion, para establecer las diferencias que se apreciaron en cuanto al transporte apical. Las imagenes obtenidas fueron fotografiadas con un microscopio estereoscopico y analizadas mediante el programa Autodesk AutoCAD® 2007. Finalmente, los datos obtenidos fueron tabulados y analizados con el programa Stata® 9.0 v. En el presente trabajo Protaper provoco menos transporte apical comparado con la tecnica manual de fuerzas balanceadas. EnglishIn order to reduce errors during root canal preparation, there have been several changes in instrumentation with rotatory systems of nickel-titanium. This is an in vitro study and the aim was to compare the degree of transportation that occurs at the union between the apical third and half third of root canals with the rotaroty Protaper Universal and nickel titanium manual system with balanced force technique. We worked with 52 mesial canals of 26 first and second maxillary and mandibular molars, which were divided into two groups. The first group (n = 28) was instrumented with rotary Protaper Universal and the second group (n = 24) was instrumented with manual technique with balanced force. The mesial roots of molars were immersed in a matrix of acrylic, which allowed manipulating the preparations with transversal cuts and comparing the wear of the root canals before and after the instrument to set the differences were observed in the apical transport. The images obtained were photographed with a stereoscopic microscope and analyzed with the Autodesk AutoCAD® 2007. Finally, the data were tabulated and analyzed with Stata® V.9.0. Protaper Universal rotatory results showed a decreased apical transport compared with the manual technique with balanced forces.

La reabsorcion centripeta del maxilar es un proceso continuo despues de la perdida dentaria. Para el tratamiento de sitios oseos deficientes, se pueden utilizar injertos de hueso autologo; como alternativa, se puede aplicar biomateriales, que no requieren sitios donantes intra o extraorales. Se describe el uso de hueso inorganico bovino (HIB) base en tres casos en diferentes modos: membrana, barrera rigida e injerto de tejido conectivo. Los resultados clinicos muestran que en todas las condiciones se formo suficiente tejido duro para permitir la rehabilitacion de implantes en los sitios de hueso insuficiente. La evaluacion histologica revelo hueso trabecular en una matriz casi madura con particulas en reposo de HIB. Dependiendo de la situacion del sitio original, se puede aplicar el concepto de barrera oclusiva rigida en dos pasos, si el hueso en reposo no proporciona la estabilidad del implante, mientras que el aumento cubierto con membrana en combinacion con tejido conectivo se recomienda si es posible la insercion simultanea de implantes.

La dentinogenesis imperfecta (DI) es un tipo de displasia de la dentina que afecta su estructura en una o ambas denticiones. La DI puede clasificarse en tres tipos. El objetivo de este informe fue demostrar las caracteristicas clinicas y radiologicas de los cuatro casos de DI en un mismo grupo familiar. Cinco hermanos fueron controlados clinica y radiograficamente. Dos individuos fueron diagnosticados, por sus caracteristicas fenotipicas y antecedentes clinicos, con el tipo de DI I; dos de ellos con DI de tipo II y un caso sin signos de DI. Es importante conocer las caracteristicas de la dentinogenesis imperfecta para poder realizar una atencion odontologica integral, lo que permitira desarrollar un diagnostico correcto y un plan de tratamiento efectivo.

Availability of adequate bone structure for dental implants is still a problem in dentistry. Alloplastic grafts, which promote bone regeneration, are used as bone substitutes in orthopedic and oral surgical procedures. The aim of this study was to evaluate the radiopacity of three different synthetic bone grafts in rabbit calvaria, over 3 months, using cone beam computed tomography (CBCT). Four critical-size defects were made on the calvaria of 11 rabbits. The lesions were classified into three groups according to the alloplastic grafts they received: Osteon® 70/30, Osteon collagen®, and Osteon II® groups. The fourth group received blood clot, and served as a control. The bone samples were collected and analyzed with CBCT after the 1st, 2nd, and 3rd month. One month after surgery, the lesions that received Osteon® 70/30 and Osteon collagen® grafts showed the highest radiopacity compared to the lesions with Osteon II® and blood clot. After the 2nd month, the radiopacity values between the three groups that received the grafts were more similar compared to the group with blood clot. After the 3rd month, the lesions with Osteon® 70/30 graft showed the highest radiopacity values, followed by Osteon collagen® and Osteon II® groups. The group that received blood clot showed the lowest radiopacity values. In conclusion, the grafts used in this study had higher radiopacity values compared to blood clot. Among the grafts used, the Osteon® 70/30 graft showed the highest radiopacity values in the 3-month period.