Insertion torque, flexural strength and surface alterations of stainless steel and titanium alloy orthodontic mini-implants: an in vitro study

ABSTRACT Objective: This study aimed to compare the insertion torque (IT), flexural strength (FS) and surface alterations between stainless steel (SS-MIs) and titanium alloy (Ti-MIs) orthodontic mini-implants. Methods: Twenty-four MIs (2 x 10 mm; SS-MIs, n = 12; Ti-MIs, n = 12) were inserted on artificial bone blocks of 20 lb/ft3 (20 PCF) and 40 lb/ft3 (40 PCF) density. The maximum IT was recorded using a digital torque meter. FS was evaluated at 2, 3 and 4 mm-deflection. Surface topography and chemical composition of MIs were assessed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). General linear and mixed models were used to assess the effect of the MI type, bone density and deflection on the evaluated outcomes. Results: The IT of Ti-MIs was 1.1 Ncm greater than that obtained for the SS-MIs (p= 0.018). The IT for MIs inserted in 40 PCF test blocks was 5.4 Ncm greater than that for those inserted in 20 PCF test blocks (p < 0.001). SS-MIs inserted in higher density bone (40 PCF) had significantly higher flexural strength than the other groups, at 2 mm (98.7 ± 5.1 Ncm), 3 mm (112.0 ± 3.9 Ncm) and 4 mm (120.0 ± 3.4 Ncm) of deflection (p< 0.001). SEM evidenced fractures in the Ti-MIs. EDS revealed incorporation of 18% of C and 2.06% of O in the loaded SS-MIs, and 3.91% of C in the loaded Ti-MIs. Conclusions: Based on the findings of this in vitro study, it seems that SS-MIs offer sufficient stability and exhibit greater mechanical strength, compared to Ti-MIs when inserted into higher density bone.

RESUMO Objetivo: O objetivo deste estudo foi comparar o torque de inserção (TI), a resistência flexural (RF) e as alterações de superfície em mini-implantes ortodônticos de aço inoxidável (MIs-Ai) e de liga de titânio (MIs-Ti). Métodos: Vinte e quatro MIs (2 x 10 mm; MIs-Ai, n = 12; MIs-Ti, n = 12) foram inseridos em blocos de osso artificial de densidades de 20 lb/ft3 (20 PCF) e 40 lb/ft3 (40 PCF). O torque máximo de inserção foi registrado por meio de um torquímetro digital. A resistência flexural foi avaliada nas deflexões de 2, 3 e 4 mm. Topografia de superfície e composição química dos MIs foram avaliadas por Microscopia Eletrônica de Varredura (MEV) e Espectroscopia de Energia Dispersiva de Raios X (EDS). Modelos lineares gerais e mistos foram utilizados para avaliar o efeito do tipo de MI, da densidade óssea e da deflexão nos desfechos avaliados. Resultados: O TI dos MIs-Ti foi 1,1 Ncm maior do que o obtido para os MIs-Ai (P = 0,018). O TI para MIs inseridos em blocos de teste de 40 PCF foi 5,4 Ncm maior do que para aqueles inseridos em blocos de teste 20 PCF (p < 0,001). MIs-Ai inseridos em osso de maior densidade (40 PCF) apresentaram resistência flexural significativamente maior do que outros grupos, em deflexões de 2 mm (98,7 ± 5,1 Ncm), 3 mm (112,0 ± 3,9 Ncm) e 4 mm (120,0 ± 3,4 Ncm) (p < 0,001). A MEV evidenciou fraturas nos MIs-Ti. A EDS revelou incorporação de 18% de C e 2,06% de O nos MIs-Ai e 3,91% de C nos MIs-Ti, ambos submetidos a testes mecânicos. Conclusões: Com base nos resultados desse estudo in vitro, os MIs-Ai aparentam oferecer adequada estabilidade e maior resistência mecânica, em comparação aos MIs-Ti, quando inseridos em osso de maior densidade.

Formación de biopelícula bacteriana sobre las superficies de pilares de cicatrización de PEEK y titanio

Objetivos. Explorar el efecto de las características de superficie sobre el volumen total y la viabilidad de la biopelícula formada sobre pilares de cicatrización de PEEK y titanio. Métodos. Los parámetros de rugosidad (S a y S k) y la energía superficial de pilares de cicatrización de PEEK y titanio (n=3) fueron determinados mediante microscopía confocal láser de barrido (CLSM) y ángulo de contacto, respectivamente. Se determinó luego el volumen total y la viabilidad de una biopelícula bacteriana multiespecie cultivada por 30 días, mediante CLSM y el reactivo LIVE/DEAD Kit BacLight. El tamaño del efecto se determinó mediante d de Cohen. Resultados. Los pilares de PEEK mostraron una mayor rugosidad que los de titanio (S a 0,41 µm vs 0,17 µm), pero no se observaron diferencias en la energía superficial. Si bien el volumen total de biopelícula fue mayor en titanio que en PEEK (696 µm3 vs 419 µm3), no hubo diferencias en la proporción de bacterias vivas entre ambos materiales. Conclusiones. La viabilidad de la biopelícula bacteriana formada no guarda relación directa con las características superficiales de pilares de cicatrización de PEEK y titanio.

Objetivo. Explorar o efeito das características da superfície no volume total e viabilidade do biofilme formado em PEEK e pilares de cicatrização de titânio. Métodos. Parâmetros de rugosidade (S a e S k) e energia de superfície de PEEK e pilares de titânio (n = 3) foram determinados por microscopia confocal de varredura a laser (CLSM) e ângulo de contato, respectivamente. O volume total e a viabilidade de um biofilme bacteriano multiespécie cultivado por 30 dias foram então determinados usando CLSM e o reagente LIVE/DEAD Kit BacLight. O tamanho do efeito foi determinado usando o d de Cohen. Resultados. Os pilares de PEEK mostraram maior rugosidade do que os de titânio (S a 0,41 µm vs 0,17 µm), mas não foram observadas diferenças na energia de superfície. Embora o volume total de biofilme tenha sido maior no titânio do que no PEEK (696 µm3 vs 419 µm3), não houve diferenças na proporção de bactérias vivas entre os dois materiais. Conclusões. A viabilidade do biofilme bacteriano formado não está diretamente relacionada às características da superfície dos pilares de cicatrização de PEEK e titânio.

Objectives . To explore the effect of surface characteristics on the total volume and viability of a bacterial biofilm developed on the surface of PEEK and titanium healing abutments. Methods. Surface parameters S a and S k, as well as the surface energy of PEEK and titanium healing abutments (n=3) were determined using confocal laser scanning microscopy (CLSM) and contact angle, respectively. The total volume and viability of a multispecies bacterial biofilm cultivated for 30 days were determined using CLSM and the LIVE/DEAD BacLight reactive kit. Effect size was determined using Cohen's d. Results. PEEK healing abutments displayed a higher surface roughness than titanium (S a 0.41 µm vs 0.17 µm), although no differences in surface energy were observed. Despite the higher total volume of the biofilm measured on titanium abutments compared to PEEK (696 µm3 vs 419 µm3), no differences in the live/dead bacterial ratio were observed. Conclusions. Bacterial viability of the biofilm did not show a direct relation to the surface characteristics of PEEK and titanium healing abutments.

Evaluation of the Implant Success Rate of Titanium-based Implant Materials: A Systematic Review and Meta-Analysis

ABSTRACT Objective: To investigate the success of implants, the increase of bone integration, and the effect of nanostructure/nanoparticles as Titanium-based implant materials on the success of implants. The present study evaluated the implant success rate of Titanium-based implant materials. Material and Methods: PICO: Population (dental implant), intervention (coated titanium implant surface), comparison (uncoated titanium implant surface), and outcome (bone-implant contact) were considered as a search strategy tool and study inclusion criteria. Searches for systematic literature were conducted on databases from Scopus, Science Direct, PubMed, ISI, Web of Knowledge, and Embase until 12 December 2022. Modified CONSORT Criteria (Reporting guidelines for preclinical in vitro studies on dental materials) were used to evaluate the quality of studies. The fixed effect model and inverse-variance method were used to calculate the 95% confidence interval for mean differences. Stata/MP V. 17 software was used to conduct the meta-analysis. Results: After reviewing the abstracts of 97 articles, studies not related to the inclusion criteria were excluded, and ten studies were selected from the remaining 39 studies after reviewing the full text. The mean difference in boneimplant contact between coated and uncoated dental implants was 0.25 (MD, 0.25 95% CI 0.01, 0.49;p=0.04). Conclusion: The titanium implant surface with nano coating can increase bone-implant contact and cause bone integration.

Comparison of Anatomic Locking Titanium Plate and Intramedullary Nail in the Treatment of Distal Tibial Fractures / 中山大学学报(医学科学版)

ObjectivesTo compare the clinical efficacy and complications of anatomic locking titanium plate （hereinafter referred to as “titanium plate screw”） and intramedullary nail in the treatment of distal tibial fractures.Methods From September 2019 to September 2021， 32 patients diagnosed with AO-A fracture of distal tibia at Sun Yat-sen Memorial Hospital of Sun Yat-sen University were included in this study. Of these， 15 cases were treated with titanium plate screws and 17 cases were treated with intramedullary nails. General surgical indexes， fracture healing time and postoperative operation were compared between the two groups.ResultsAll patients were followed up for 10 to 20 months， with an average of 12 months. The operative time and intraoperative fluoroscopy times of intramedullary nail group were longer than those of titanium plate screw group， but the preoperative waiting time and hospitalization days was less or were fewer than those of titanium plate screw group， the difference was statistically significant （P < 0.05）. There was no significant difference in fracture healing time between the two groups （P> 0.05）. At 6 weeks after operation， VAS scores in both groups were lower than those before operation， with statistically significant difference （P<0.05）. There was no significant difference in VAS scores between the intramedullary nail group and the titanium plate screw group （P> 0.05）. AOFAS scores 6 months after surgery， ankle joint motion and complication rate 1 year after surgery in intramedullary screw group were better than those in titanium plate screw group， and the differences were statistically significant （P< 0.05）. There was no significant difference in AOFAS scores between the two groups at 1 year after operation （P> 0.05）.ConclusionTitanium plate screw and intramedullary nail are both effective methods for the treatment of distal tibial AO-A fracture， and there is no significant difference in long-term clinical efficacy. Intramedullary nail has fewer soft tissue complications， less impact on ankle motion， faster recovery and higher safety， while titanium plate screw has a higher probability of postoperative soft tissue infection. We suggest that in clinical work， preoperative evaluation of patients should be done well. Under the premise of grasping the indications， intramedullary nail has fewer complications and certain advantages.

In vitro study on cyclic fatigue resistance of three types of nickel titanium files in preparation for bending root canals / 口腔疾病防治

Objective@#The purpose of this study was to investigate the differences in the anti cyclic fatigue performance of Woride KS (WKS), Proteper Gold (PTG), and Hyflex CM (HCM) nickel titanium instruments with different tip diameters in curved root canal models, and to provide reference for the targeted selection of suitable nickel titanium instruments in clinical preparation of curved root canals.

Preparation of an amino hybrid mesoporous silica-based nanotopography protective coating on a titanium implant surface and evaluation of its osteogenic effect / 口腔疾病防治

Objective@#To deposit degradable amino-hybrid mesoporous silica (AHMS) in situ on the surface of titanium nanotube (TNT) and explore its protective effect on nanomorphology and osteogenesis.@*Methods@#TNT and TNT@AHMS were sequentially prepared via an anodizing method: the oil-water two-phase method (experimental group) and the acid-etched titanium method [control group (Ti)]. The parameters for synthesis were explored by changing the silicon source dosage ratio (3∶1, 1∶1, 1∶3); the surface morphology was observed by scanning electron microscope(SEM), hydrophilicity was detected by Water Contact Angle Tester, elemental composition was detected by X-ray photoelectron spectroscopy (XPS); nanoindentation test and ultrasonic oscillator were used to observe the morphological holding effect as mechanical strength of TNT@AHMS in vitro; simulated immersion experiments in vitro was used to observe the degradation behavior of the material. the MC3T3-E1 cell line was used to observe the effect of cell adhesion, proliferation and differentiation on the material; and an SD rat femoral implant model and micro-CT were used to verify the protective effect and osseointegration effect of AHMS on TNT morphology.@*Results@#The morphologies of TNT and TNT@AHMS were successfully prepared, and the silicon source ratio was 1:3. SEM showed that the titanium nanotubes were uniformly covered with AHMS coating, and the mesoporous pore size was about 4 nm. After AHMS was incorporated, the surface of the material was hydrophilic (12.78°), the presence of amino groups (NH2-) was detected, the material was completely degraded within 12 h in vitro, and the active morphology of the TNT was re-exposed with a cumulative silicon release of 10 ppm. Nanoindentation test showed that TNT@AHMS exhibited more ideal surface mechanical strength. SEM revealed that TNT maintains its own morphology under the protection of AHMS, and the TNT group suffered severe exfoliation. In addition, the early adhesion and proliferation rates, ALP activity, and bone volume fraction of cells on the TNT@AHMS surface 4 weeks after implantation were significantly higher than those in the TNT group.@*Conclusion@#By depositing AHMS on the surface of TNT, the nanotopography can be protected. It not only prevents the active base topography from exerting subsequent biological effects but also further endows the material with the ability to promote bone regeneration, laying a foundation for the future development of nanotopography-modified titanium implants.

Autologous ilium graft combination with titanium plate for sternal reconstruction: A case report / 中国胸心血管外科临床杂志

@#The sternum is the pivotal component of the thoracic cavity. It is connected with the clavicle and ribs on the upper part and both sides respectively, and plays an important role in protecting the stability of the chest wall. Sternal resection usually results in a large segmental chest wall defect that causes the chest wall to float and requires sternal reconstruction. This paper reports a 62 years male patient with thymic squamous cell carcinoma with sternal metastasis, who underwent thymotomy, sternal tumor resection and autologous lilum graft combined with sternal reconstruction by titanium plate after relevant examination was completed and surgical contraindications were eliminated. The patient was followed up for 6 months, the respiratory and motor functions were normal and the thoracic appearance was good.

Nanotopography and oral bacterial adhesion on titanium surfaces: in vitro and in vivo studies

Abstract The present study aimed to evaluate the influence of titanium surface nanotopography on the initial bacterial adhesion process by in vivo and in vitro study models. Titanium disks were produced and characterized according to their surface topography: machined (Ti-M), microtopography (Ti-Micro), and nanotopography (Ti-Nano). For the in vivo study, 18 subjects wore oral acrylic splints containing 2 disks from each group for 24 h (n = 36). After this period, the disks were removed from the splints and evaluated by microbial culture method, scanning electron microscopy (SEM), and qPCR for quantification of Streptococcus oralis, Actinomyces naeslundii, Fusobacterium nucleatum, as well as total bacteria. For the in vitro study, adhesion tests were performed with the species S. oralis and A. naeslundii for 24 h. Data were compared by ANOVA, with Tukey's post-test. Regarding the in vivo study, both the total aerobic and total anaerobic bacteria counts were similar among groups (p > 0.05). In qPCR, there was no difference among groups of bacteria adhered to the disks (p > 0.05), except for A. naeslundii, which was found in lower proportions in the Ti-Nano group (p < 0.05). In the SEM analysis, the groups had a similar bacterial distribution, with a predominance of cocci and few bacilli. In the in vitro study, there was no difference in the adhesion profile for S. oralis and A. naeslundii after 24 h of biofilm formation (p > 0.05). Thus, we conclude that micro- and nanotopography do not affect bacterial adhesion, considering an initial period of biofilm formation.

Evaluation the scanning accuracy of Blue-Light laboratory scanners in complete edentulous Maxilla with multiple implants with titanium scan bodies / Evaluación de la precisión de escaneado de los escáneres de laboratorio de luz azul en maxilares desdentados completos con implantes múltiples con cuerpos de escaneado de titanio

Abstract To evaluate the accuracy of complete arch scanning with multiple implant titanium scan bodies using laboratory scanners. A master model of an edentulous maxillary arch with 6 implants was fabricated. Titanium scan bodies were inserted into the model. Three laboratory scanners were used: D2000 (3Shape), Vinyl High Resolution (Smart Optics), and inEos X5 (Dentsply Sirona). The master model was consecutively scanned ten times using dental laboratory scanners (LS) without detaching and repositioning the scan bodies. Linear and angular accuracy between adjacent implants was measured using inspection software (Control X, Geomagic). The accuracy of the complete arch scans was calculated. Implant regions were defined as; parallel (R1: #24-26 and #16-14), angled (R2: #22-24 and #14-12), angled to occlusal plane (R3: #12-22), and cross-arch (R4: #16-26). The effect of LS and implant region on accuracy was compared using two-Way ANOVA (α=0.05). Significant greater linear distortion was noted in R4 (61.2±17.9µm) compared to R1 (23.4±15.5µm) and R2 (26±17.7µm) (p<0.01). Greater linear distortions were noted in R4 with D2000 (0.07±0.016 degrees) and Vinyl High Resolution (0.067±0.02 degrees) than inEos X5 (0.032±0.021 degrees) (p>0.05). Greater mean linear precisions were noted in R1 (9±8µm) and R3 (9.3±8.3µm) than R4 (12.6±10.3µm) (p<0.05). The highest linear precision was noted in D2000 (7.2±7.6µm) (p<0.05). The angular precision of D2000 (0.02±0.015 degrees) was the highest (p<0.01). The angular precisión of R4 (0.036±0.018 degrees) was the lowest (p<0.01). This study revealed that the trueness was affected by the implant region and the precision was affected by both LS and implant region.

Resumen Evaluar la precisión del escaneado de la arcada completa con cuerpos de escaneado de titanio de múltiples implantes utilizando escáneres de laboratorio. Se fabricó un modelo maestro de una arcada maxilar edéntula con 6 implantes. Se insertaron cuerpos de escaneo de titanio en el modelo. Se utilizaron tres escáneres de laboratorio: D2000 (3Shape), Vinyl High Resolution (Smart Optics) e inEos X5 (Dentsply Sirona). El modelo maestro se escaneó consecutivamente diez veces usando escáneres de laboratorio dental (LS) sin separar y reposicionar los cuerpos de escaneo. La precisión lineal y angular entre implantes adyacentes se midió utilizando un software de inspección (Control X, Geomagic). Se calculó la precisión de los escaneos completos del arco. Las regiones del implante se definieron como; paralelo (R1: #24-26 y #16-14), angulado (R2: #22-24 y #14-12), angulado al plano oclusal (R3: #12-22) y cruzado (R4: #16-26). El efecto de LS y la región del implante en la precisión se comparó mediante ANOVA de dos vías (α=0,05). Se observó una distorsión lineal significativamente mayor en R4 (61,2±17,9µm) en comparación con R1 (23,4±15,5µm) y R2 (26 ±17,7µm) (p<0,01). Se observaron mayores distorsiones lineales en R4 con D2000 (0,07±0,016 grados) y vinilo de alta resolución (0,067±0,02 grados) que en inEos X5 (0,032±0,021 grados) (p>0,05). Se observaron precisiones lineales medias mayores en R1 (9±8µm) y R3 (9,3±8,3µm) que en R4 (12,6±10,3µm) (p<0,05). La mayor precisión lineal se observó en D2000 (7,2±7,6 µm) (p<0,05). La precisión angular de D2000 (0,02±0,015 grados) fue la más alta (p<0,01). La precisión angular de R4 (0,036±0,018 grados) fue la más baja (p<0,01). Este estudio reveló que la veracidad se vio afectada por la región del implante y la precisión se vio afectada tanto por LS como por la región del implante.

Comparación Placas de Titanio vs. Placas Reabsorbibles en Fracturas de Orbita: Revisión de literatura / Comparison of Titanium Plates vs. Resorbable Plates in Orbital Fractures: Literature Review

RESUMEN Introducción: Los tratamientos para fracturas de órbita se basan en la corrección del defecto de las lesiones orbitarias de tipo blow in y blow out (o de estallido), mediante diversas placas y mallas biocompatibles con el organismo, dándose una cicatrización de primera generación evitando un callo óseo y una fijación más rígida. Para el diagnóstico de este tipo de lesiones tenemos inflamación periorbitaria, enoftalmos, diplopía, equimosis, hemorragia subconjuntival. Existen diversos materiales reconstructivos siendo estos compuestos por distintas materias primas, como son los aloplásticos y autógenos; donde encontramos varios tipos como placas de titanio y las placas reabsorbibles siendo estas las más comunes y usadas actualmente, por su bajo estímulo a reabsorciones óseas y evitando efectos secundarios a largo plazo. Estas placas presentan diversos grados de ductilidad y resistencia. Se informó sobre varias complicaciones según el tipo de placas como es la cicatrización, las cirugías postquirúrgicas en caso de placas de titanio, etc. El objetivo de esta revisión es la evaluación de la eficacia las placas reabsorbibles versus placas de titanio en fracturas de órbita. Materiales y métodos: La investigación es de carácter documental, descriptivo y no experimental. En el cual se emplea una metodología de identificación e inclusión de artículos científicos tipo prisma. Resultados y conclusiones: Se verificaron las ventajas y desventajas tanto de las placas reabsorbibles como las de titanio siendo estas similares en la biocompatibilidad con el organismo humano, así como también varias diferencias como el soporte, fuerzas, resistencia de estas, concluyendo que es debatible el material ideal para tratar fracturas de órbita. Se seleccionaron artículos tomando en cuenta el título y objetivos; considerando estudios comparativos, revisiones sistemáticas, revisiones de literatura, los cuales comprendían criterios con respecto a fracturas de órbita y tratamientos quirúrgicos. La búsqueda arrojó 55 artículos en PubMed, 65 en Google, 4 en Scielo y 29 en Science direct, de los cuales se excluyeron libros, monografías, estudios experimentales, dando como resultado 21 artículos para el desarrollo de esta revisión bibliográfica. Y que fueron leídos y analizados en su totalidad, estudiando los objetivos, metodología y conclusión de cada uno de ellos para la posterior comparación.

ABSTRACT Introduction: Treatments for orbit fractures are based on the correction of the defect of blow in and blow out orbital injuries, by means of various plates and meshes biocompatible with the organism, giving a first-generation healing avoiding a bony callus and a more rigid fixation. For the diagnosis of this type of lesions we have periorbital inflammation, enophthalmos, diplopia, ecchymosis, subconjunctival hemorrhage. There are several reconstructive materials being these composed of different raw materials, such as alloplastic and autogenous, where we find several types such as titanium plates and resorbable plates being these the most common and currently used, for its low stimulus to bone resorption and avoiding long-term side effects. These plates have different degrees of ductility and resistance. Several complications have been reported depending on the type of plates, such as scarring, post-surgical surgeries in the case of titanium plates, etc. The objective of this review is to evaluate the efficacy of resorbable versus titanium plates in orbital fractures. Materials and methods: This research are a documentary, descriptive and non-experimental nature. A prism-type methodology of identification and inclusion of scientific articles was used. Results and conclusions: The advantages and disadvantages of both resorbable and titanium plates were verified, being these similar in biocompatibility with the human organism, as well as several differences such as support, forces, resistance of the same, concluding that it is debatable. The ideal material to treat orbital fractures. Articles were selected considering the title and objectives; considering comparative studies, systematic reviews, literature reviews, which included criteria regarding orbital fractures and surgical treatments. The search yielded 55 articles in PubMed, 65 in Google, 4 in Scielo and 29 in Science direct, from which books, monographs, experimental studies were excluded, resulting in 21 articles for the development of this bibliographic review. The 21 articles were read and analyzed in their entirety, studying the objectives, methodology and conclusion of each one of them for subsequent comparison.

Comparative Assessment of Contact Osteogenesis at the Titanium Implant-Bone Junction in Male Rabbits with Dissimilar Femoral Defects / Evaluación Comparativa de la Osteogénesis de Contacto en la Unión entre el Hueso y el Implante de Titanio en Conejos Macho con Defectos Femorales Diferentes

SUMMARY: Traumatized bone tissue has the capacity to repair itself so that it eventually regains its almost original form, even in the case of artificially inserted implants. The process that stays at the base of the regeneration is represented by osteogenesis or remote osteogenesis. The major difference between the two types of bone formation is the location of the cement line, which is located on the surface of the implant for contact osteogenesis and on the surface of the bone defect for remote osteogenesis. The aim of the present study was to assess the contact osteogenesis in the case of inserted titanium screws in holes with diameters of 1.8 mm and 1 mm respectively. The obtained results show, in the case of the groove with 1.8 mm that the newly proliferated bone represents 73.85 % of the total area, while in the case of the groove with 1 mm in diameter the value of the newly proliferated bone is 26.15 %. In conclusion, the insertion of titanium screws by self-tapping into the hole smaller than the core of the screw is accompanied by bone proliferation by contact osteogenesis much more modest than in the case of insertion into the hole larger than the core of the screw.

El tejido óseo traumatizado tiene la capacidad de reparar en forma espontánea, de modo que eventualmente recupera su forma casi original, incluso en el caso de implantes insertados artificialmente. El proceso que queda en la base de la regeneración está representado por la osteogénesis u osteogénesis a distancia. La principal diferencia entre los dos tipos de formación ósea es la ubicación de la línea de cemento, que se encuentra en la superficie del implante para la osteogénesis de contacto y en la superficie del defecto óseo para la osteogénesis remota. El objetivo del presente estudio fue evaluar la osteogénesis de contacto en el caso de tornillos de titanio insertados en forámenes con diámetros de 1,8 mm y 1 mm respectivamente. Los resultados obtenidos muestran, en el caso del surco de 1,8 mm que el hueso neoproliferado representa el 73,85 % del área total, mientras que en el caso del surco de 1 mm de diámetro el valor del hueso neoproliferado es del 26,15 %. En conclusión, la inserción de tornillos de titanio por autorroscantes en el foramen menor que el núcleo del tornillo se acompaña de una proliferación ósea por osteogénesis de contacto mucho más modesta que en el caso de la inserción en el foramen mayor que el núcleo del tornillo.

CYCLIC AND TORSIONAL FATIGUE RESISTANCE OF THERMALLY TREATED ROTARY NiTiINSTRUMENTS WITH DIFFERENT DESIGNS

Aims: The aim was to evaluate the cyclic and torsional fatigue resistance among thermally treated NiTi rotary instruments with different design features.Materials and methods: Sixty instruments of three systems were used (n=20): TruNatomy 26.04 (TN 26.04), BassiLogic 25.05 (BL 25.05), and Flat File 25.04 (FF 25.04). The cyclic fatigue test (n=10) was performed to evaluate the time to fracture (s) and the number of cycles until failure (NCF). The torsion test was performed to evaluate the torque (N.cm) and maximum angular deflection until fracture (n=10). The fracture surface of each fragment was examined under a scanning electron microscope. The data were analyzed by Tukey's test (p<0.05).Results: BL 25.05 and FF 25.04 instruments had a higher number of cycles and time to fracture compared with TN 26.04 (p<0.05). TN 26.04 instruments showed lower torque to fracture.Conclusions: Based on the proposed objectives and the methodology used, TruNatomy 26.04 instruments present lower resistance to cyclic fatigue and torsional fatigue when compared to BassiLogic 25.05 and Flat File 25.04 instruments.

UTILIZAÇÃO CLÍNICA DO TETRAFLUORETO DE TITÂNIO NA ODONTOLOGIA: UMA REVISÃO CRÍTICA / CLINICAL USE OF TITANIUM TETRAFLUORIDE IN DENTISTRY: A CRITICAL REVIEW

Objetivo: avaliar a eficácia preventiva e terapêutica do tetrafluoreto de titânio (TiF4) em ensaios clínicos randomizados (ECR) e não randomizados (N-ECR). Materiais e Métodos: estudos sobre a eficácia do tetrafluoreto de titânio em esmalte e dentina, testado em diferentes veículos e formulações, foram obtidos nas seguintes bases de dados: PubMed, Cochrane Library, Scopus, Web of Science, LILACS/BBO e EMBASE, sem limite de ano de publicação ou idioma. Resultados: seis estudos com abordagem preventiva e terapêutica do TiF4 sobre a superfície dentária foram incluídos. Destes, três ECR e três N-ECR. Por meio da tabulação e categorização dos artigos, notou-se que o TiF4 obteve efeito positivo na prevenção da cárie em três estudos; efeito nulo no tratamento de lesões cariosas em dois; e apenas um estudo apresentou efeito negativo no tratamento da erosão quando comparado aos outros compostos fluoretados. Conclusão: Embora haja estudos na literatura, com distintos delineamentos metodológicos comprovando a eficácia do TiF4, tanto na prevenção quanto no tratamento de lesões de cárie e erosivas, ainda é necessário que mais ensaios clínicos randomizados sejam realizados, com o intuito de validar a eficácia da utilização clínica deste composto fluoretado.

Objective: to analyze the preventive and therapeutic efficacy of titanium tetrafluoride (TiF4) in studies with a methodological design based on randomized clinical trials (RCT) and non-randomized (N-RCT). Materials and Methods: data on the behavior of titanium tetrafluoride in enamel and dentin, tested in several vehicles and formulations, were extracted in the following databases: PubMed, Cochrane Library, Scopus, Web of Science, LILACS/BBO and EMBASE, without limitation of publication year or language. Results: six studies were obtained with preventive and therapeutic approach of TiF4 on the dental surface. Three studies were RCT and three were N-RCT. Through tabulation and categorization of articles, it was noticed that TiF4 showed a positive effect in caries prevention in three studies; a null effect in caries treatment was observed in two; and only one study had a negative effect in erosion treatment when compared to the other fluoridated compounds. Conclusion: Although there are several studies in the literature, with different methodological designs, proving the efficacy of TiF4 both in prevention and in therapeutic treatments of caries and dental erosion, it is still necessary that more clinical controlled studies be conducted, in order to validate the clinical use efficacy of this fluoride compound.

STUDY ON THE EFFECT OF BRASS AND COPPER ELECTRODES DURING ELECTRIC DISCHARGE MACHINING OF INCONEL 718 USING NANO PARTICLES MIXED DIELECTRIC FLUID.

Electrical Discharge Machine (EDM) parameters have a significant influence on machining characteristic like material removal rate (MMR) and tool wear rate (TWR). Inconel 718, which is widely used in the Medical, Marine, Architectural and food processing industries, is used as a work material. The tool electrode materials used are brass and copper. Experiments are conducted using face centered central composite design to determine the effects of process parameters like current rate, pulse on time, pulse off time and concentration of titanium carbide nano particle in dielectric fiuid. Based upon the experimental outcomes, the effect of brass and copper electrodes during electric discharge machining of Inconel 718 using nano particles mixed dielectric fiuid was investigated.

ASSESSMENT OF TORSION RESISTANCE OF GLIDE PATH ROTARY INSTRUMENTS

NiTi endodontic instruments for glide path are the most susceptible to fractures inside the root canal, mainly as a result of high torsional stress. Objective: The present study investigated the resistance to torsion and angular deflection of instruments destined for the glide path: ProGlider #16.02; T-File #17.02 and the MK Life #16.02. Materials and methods: Thirty rotating NiTi glide path instruments (n=10) with 25mm lengths were selected. The torsion test was performed based on ISO 3630-01 (1992). Three millimeters from the tip of the instruments, it was attached to a small load cell by a lever arm connected to the torsion shaft. Torsional strength and angular deflection were evaluated. Fracture surfaces were examined by scanning electron microscopy with magnifications of 1000x and 5000x in the cross section, and 50x in the lateral section. Statistical analysis was performed using the Kruskal-Wallis H test, followed by the Down's post hoc test. Results: The ProGlider instrument showed greater torsional strength (p<0.05) compared to the T-File (p<0.05) and MK Life (p<0.05), respectively. However, the T-File showed greater angular deflection (p<0.05) than the other groups tested. Conclusion: It can be concluded that the ProGlider instrument presented greater torque for the fracture, while the T-File instrument presented greater angular deflection.

Inhibitory Effect of Gallium Nitrate against Staphylococcus aureus and Its Action on the Formation of Biofilms on Titanium Surfaces

Aims: This study aimed to investigate the effect of gallium nitrate [Ga(NO3)3], an inorganic antimicrobial agent, against the growth and biofilm formation of Staphylococcus aureus on the titanium surface. Study Design: This study is a laboratory investigation involving the determination of the inhibitory concentration (IC) of Ga(NO3) 3 against the planktonic strain of S. aureus and biofilm formation on titanium coupons. Place and Duration of Study: Sample: Center of Science and Technology for Sustainability (CCTS), Federal University of São Carlos, SP, Brazil, between March 2020 and March 2022. Methodology: The inhibitory concentration of gallium nitrate was determined in a 96-well microtiter plate in Muller Hinton broth. The potential of the antimicrobial agent to inhibit biofilm formation by S. aureus on titanium surfaces was evaluated by Scanning Electron Microscopy (SEM). The cytotoxicity potential of Ga(NO3)3 was determined on V79 cells. Results: The results showed that the susceptibility of gallium nitrate against S. aureus was 1.40 µM, while SEM images revealed that concentrations of 90 µM inhibited biofilm formation by S. aureus. Conclusion: This research has shown promising results regarding gallium nitrate's potential of inhibiting the growth of both planktonic and sessile S. aureus cells. In addition, coating titanium surfaces with Ga(NO3)3 would be an extra alternative to prevent implant-associated infections due to its non-toxicity to cells.

Influence of temperature on the torsional properties of two thermally treated NiTi rotary instruments

Abstract This study aimed to evaluate the influence of temperature on torsional strength and angular deflection of two experimental NiTi rotary instruments manufactured from Blue and Gold thermal treatments and with identical cross-sections. A total of 40 experimental NiTi instruments 25.06 and with a triangular cross-section and manufactured from Blue and Gold thermal treatments were used (n=20). The torsional test was performed in the 3 mm from the tip of the instrument according to ISO 3630-1. The torsional test evaluated the torsional strength and angular deflection to failure at room temperature (21°C ± 1° C) and body temperature (36°C ±1°C). The fractured surface of each fragment was observed by using scanning electron microscopy (SEM). Data were analyzed using an unpaired t test for inter and intra-group comparison and the level of significance was set at 5%. The results showed that the body temperature did not affect the torsional strength and angular deflection of the instruments when compared with room temperature (P>0.05). However, at body temperature, the Blue NiTi instruments presented significantly lower angular deflection in comparison with Gold NiTi instruments (P<0.05). There was no significant difference regarding the torsional strength of the instruments at body temperature (P>0.05). The temperature did not affect the torsional strength of the instruments manufactured from Blue and Gold technology. However, the Blue NiTi instruments presented significantly lower angular deflection than Gold instruments at 36°C temperature.

Resumo O objetivo deste estudo foi avaliar a influência da temperatura nas propriedades de torção (resistência à torção e deflexão angular) de dois instrumentos rotatórios experimentais de NiTi fabricados com secção triangu.ar e tratamentos térmicos Blue e Gold. Quarenta instrumentos experimentais de NiTi 25.06 com tratamento térmico Blue e Gold foram usados (n= 20). Foi avaliada a resistência torcional e a deflexão angular até a fratura na temperatura ambiente (21°C ± 1°C) e corporal (36°C ± 1°C). O teste torcional foi realizado nos 3 mm da ponta dos instrumentos de acordo com a ISO 3630-1. A superfície fraturada de cada instrumento foi observada pelo microscópio eletrônico de varredura (MEV). Os dados foram analisados por meio do teste t não pareado para a comparação inter e intragrupos e o nível de significância à 5%. Os resultados demonstraram que a temperatura corporal não afetou a resistência a torção e deflexão angular quando comparada com a temperatura ambiente (P>0.05). No entanto, na temperatura de 36°C o instrumento com tratamento térmico Blue apresentou menor deflexão angular quando comparado com o Gold (P<0.05). Não houve diferença significante entre os dois instrumentos em relação a resistência à torção. A temperatura corporal não modificou a resistência torcional dos instrumentos fabricados com tecnologia Blue e Gold. No entanto, os instrumentos com NiTi Blue apresentaram menor deflexão angular do que o Gold a 36°C.

Regulación de la implantología dental en México / Regulation of dental implantology in Mexico

Introducción: los implantes dentales se han convertido en uno de los tratamientos odontológicos con mayor demanda en todo el mundo, no sólo por el nivel máximo de funcionalidad y de estética, sino también debido a su estabilidad, osteointegración y facilidad en su rehabilitación. Es incierto si los implantes dentales se encuentran normados formalmente en México, lo que motiva a la revisión del estado actual. Objetivo: evidenciar el estado actual de la legislación de la práctica de la implantología dental en México a través de una revisión en la literatura. Material y métodos: revisión de las legislaciones existentes en México para la aplicación de implantes dentales y su contraparte en el mundo a través de la evaluación de normas expedidas en América y Europa. Resultados: se contabilizó un total de 17 escuelas de implantes dentales que cuentan con el reconocimiento de la Secretaría de Educación Pública, de las cuales tres son públicas y 14 privadas. Se presentó una discrepancia en los planes de estudio que va de 16 a 36 meses. Las escuelas no contaron con un aval normativo. Las normas internacionales para control de calidad y aplicación de la tecnología en implantes se ubicaron en Canadá, Estados Unidos, España, Reino Unido y Francia. Conclusiones: contar con un antecedente normativo establecido por los países de primer mundo y ausente en México permite evidenciar la necesidad de implementar una Norma Oficial Mexicana que regule la fabricación, distribución y almacenamiento de los implantes dentales en México. A la vez, la revisión sugiere que la Secretaría de Educación Pública norme los créditos mínimos necesarios en las instituciones educativas reconocidas para la formación de recursos humanos que ejercen la implantología dental (AU)

Introduction: dental implants have become one of the dental treatments with the highest demand in the world, not only because of the highest level of functionality and aesthetics, but also because of their stability, osseointegration and ease of rehabilitation. It is uncertain if dental implants are formally regulated in Mexico, which motivates the review of the current status. Objective: to demonstrate the current state of the legislation for the practice of dental implantology in Mexico through a review of the literature. Material and methods: review of the existing legislation in Mexico, for the application of dental implants and its counterpart in the world, through the evaluation of standards issued in America and Europe. Results: a total of 17 dental implant schools that have the recognition of the Ministry of Public Education were counted, of which 3 are public and 14 private. There was a discrepancy in the study plans that ranged from 16 to 36 months. Schools will not have regulatory backing. The international standards for quality control and application of technology in implants were located in Canada, the United States, Spain, the United Kingdom and France. Conclusions: having a normative antecedent established by the countries of the first world and absent in Mexico, allows to demonstrate the need for the implementation of an Official Mexican Standard, which regulates the manufacture, distribution and storage of dental implants in Mexico. At the same time, the review suggests that the Ministry of Public Education regulate the minimum necessary credits in recognized educational institutions, for the training of human resources that practice dental implantology (AU)

Dentin permeability after pretreatment with titanium tetrafluoride and self-etching or universal adhesive systems

Aim: To evaluate dentin permeability after pretreatment with 2.5% aqueous solution of titanium tetrafluoride (TiF4), followed by a self-etching universal adhesive system. Methods: Forty dentin discs (1.5 mm thick) were randomly divided into groups according to the application or non-application of a pretreatment, and the type of adhesive system to be tested (two-step self-etching/ Clearfil SE Bond/ Kuraray Medical, or universal adhesive system/ Single Bond Universal/ 3M ESPE). Both sides of the discs were conditioned with 37% phosphoric acid to remove the smear layer. The first hydraulic conductivity measurement (L1) was performed in a permeability machine, under 5 PSI pressure. The samples were sanded again to form a standardized smear layer. The teeth designated for pre-treatment with TiF4 received the TiF4 solutions applied actively for 60 seconds, and the adhesive systems were applied according to the manufacturer's instructions. Then, a new hydraulic conductivity measurement (L2) was performed for the purpose of calculating the hydraulic conductance at a later time, considering the water viscosity and the thickness of the specimen. The percentage (L) of dentin permeability after application of the adhesive system was obtained (L (%) = [(L1-L2) x100] / L1). The Mann-Whitney non-parametric test was applied. Results: There was no difference between the two adhesive systems, or between the groups with or without pretreatment, as regards dentin permeability (p>0.05). Conclusion: Pretreatment with 2.5% TiF4 did not influence dentin permeability, irrespective of the adhesive system used

Does Elective Sternal Plating Combined with Steel Wire Reduce Sternal Complication Rates in Patients with Obesity?

ABSTRACT Introduction: In this study, sternal complication rates of sternal closures with steel wire or steel wire combined with titanium plate in patients with obesity that underwent cardiac surgery were investigated. Methods: The data of 316 patients that underwent cardiac surgery between May 2018 and October 2021 were analyzed retrospectively; 124 patients withbody mass index (BMI) ≥ 30 kg/m2 were divided into group I, patients whose sternotomy was performed with steel wires, and group II, patients whose sternotomy was performed with steel wire combined with titanium plates. Results: A total of 124 patients with BMI ≥ 30 kg/m2 were divided into group I (n=88 [70.9%]) and group II (n=36 [29.1%]). The rate of male patients was found to be significantly higher in group I, whereas the rate of female patients was significantly higher in group II (P<0.001). BMI values were found to be low in group I and high in group II (P<0.001). The distribution of complications was different in the BMI ≥ 35.00-39.99 kg/m2 and ≥ 40 kg/m2 groups (P=0.003). Development of complications was found to be higher in patients with BMI ≥ 40 kg/m2. Sternal dehiscence was observed in two patients in group I, while no dehiscence was observed in group II. Conclusion: The lower incidence of complications and the absence of non-infectious sternal complications and sternal dehiscence in patients with BMI ≥ 35 kg/m2 that underwent steel wire combined titanium plate sternal closure strengthened the idea that plate-supported sternal closure can prevent sternal complications in high-risk patients.