Eighteen-month clinical evaluation of a new universal adhesive applied in the "no-waiting" technique: a randomized clinical trial.

OBJECTIVE: The aim of this double-blind, randomized clinical trial was to evaluate the 6- and 18-month clinical performances of a new universal adhesive applied in the "no-waiting" (NW) technique to non-carious cervical lesions (NCCLs) using two evaluation criteria. MATERIALS AND METHODS: One hundred and seventy-six restorations were assigned to four groups according to the adhesive system, adhesive strategy, and application mode: Prime&Bond Active (PB) applied using the etch-and-rinse (ER) and self-etch (SE) strategies with 20 s applications and Clearfil Universal Bond Quick (CQ) applied using the ER and SE strategies with the NW technique. The composite resin restorations were evaluated at baseline and after 6 and 18 months using the World Dental Federation (FDI) and US Public Health Service (USPHS) criteria. The Friedman repeated measures analysis of variance and Wilcoxon test were used for statistical analyses (α = 0.05). RESULTS: No significant differences were observed among any of the groups or criteria after 6 months (p > 0.05). After 18 months, 10 restorations were lost (p > 0.05) (2 with PB-ER [95.5%; 95%CI: 92-100%], 4 with PB-SE [90.9%; 95%CI: 82-98%], 0 with CQ-ER [100%; 95%CI: 92-100%], and 4 with CQ-SE [90.9%; 82-98%]). The restorations performed with the SE strategy showed more marginal discrepancies than those performed with the ER strategy, mainly when the FDI criteria were used (p < 0.05). Those that used the PB-SE showed fewer marginal discrepancies than those that used the CQ-SE (FDI; p < 0.05). A few restorations showed marginal discrepancies after the USPHS analysis (p > 0.05). CONCLUSIONS: The results when using the CQ-SE and -ER strategies with the NW technique were similar to those when using the PB-SE and -ER strategies in standard applications to non-carious cervical lesions after 6 and 18 months of clinical evaluation. CLINICAL RELEVANCE: After 6 and 18 months, the application of Clearfil Universal Bond Quick with the "no-waiting" technique showed similar clinical performance compared to the standard application of Prime & Bond Active applied using the standard application time (20 s). TRIAL REGISTRATION: ClinicalTrials.gov identifier RBR-5f9gps.

Inflammatory parameters and color alterations of dental bleaching in patients wearing fixed orthodontic appliance: a randomized clinical trial.

BACKGROUND: Many orthodontic patients request dental bleaching during orthodontic treatment to achieve a faster aesthetic resolution, however, no attention has been paid to the inflammatory processes that can occur when both therapies are indicated together. So, this clinical trial evaluated the inflammatory parameters and color alterations associated with dental bleaching in patients wearing a fixed orthodontic appliance. METHODS: Thirty individuals aged between 18 and 40 years were equally and randomly allocated into three groups: FOA (fixed orthodontic appliance), BLE (dental bleaching), and FOA + BLE (fixed orthodontic appliance + dental bleaching). The orthodontic appliances and the bleaching procedures were performed in the maxillary premolars and molars. For dental bleaching a 35% hydrogen peroxide was used. The gingival crevicular fluid (GCF) and nitric oxide (NO-) levels were evaluated at different time-points. Color evaluation was performed using an Easyshade spectrophotometer at baseline (FOA, FOA + BLE, BLE), one month after (FOA + BLE) and 21 days after appliance removing (FOA + BLE and FOA groups), in each tooth bleached. The ANOVA and Tukey's tests, with a significance level of 5%, were used for statistical analysis. RESULTS: The GCF volume in the FOA + BLE and FOA groups significantly increased at the time points evaluated (p < 0.001); however, this did not occur in the BLE group (p > 0.05). On the other hand, NO- levels significantly decreased during dental bleaching with or without fixed orthodontic appliances (FOA + BLE and BLE groups; p < 0.05), while no significant changes were observed in the FOA group (p > 0.05). Significant changes in color were observed in the FOA + BLE and BLE groups compared to in the FOA group (p < 0.01). However, the presence of fixed orthodontic appliance (FOA + BLE) negatively affected the bleaching efficacy compared to BLE group (p < 0.01). CONCLUSIONS: Dental bleaching did not increase the inflammatory parameters in patients wearing fixed orthodontic appliance. However, in the presence of orthodontic appliances, the bleaching efficacy was lower than that of bleaching teeth without orthodontic appliances. TRIAL REGISTRATION: RBR-3sqsh8 (first trial registration: 09/07/2018).

Radiopacity of Methacrylate and Silorane Composite Resins Using a Digital Radiographic System.

The aim of this study was to evaluate the radiopacity of silorane and methacrylate resin composites, comparing them to the enamel, dentin, and aluminum penetrometer using a digital image. From six resin composites (Filtek™ P90, Filtek Z350, Filtek Z350 XT flow, Tetric Ceram, TPH Spectrum, and SureFil SDR flow) cylindrical disks (5 × 1 mm) were made and radiographed by a digital method, together with a 15-step aluminum step-wedge and a 1 mm slice of human tooth. The degree of radiopacity of each image was quantified using digital image processing. The mean values of the shades of gray of the tested materials were measured and the equivalent width of aluminum was calculated for each resin. The results of our work yielded the following radiopacity values, given here in descending order: Tetric Ceram > TPH > SDR > Z350 > Z350 flow > P90 > enamel > dentin. The radiopacity of the materials was different both for the enamel and for the dentin, except for resin P90, which was no different than enamel. In conclusion, silorane-based resin exhibited a radiopacity higher than dentin and closest to the enamel; a large portion of the methacrylate-based flow and conventional resins demonstrated greater radiopacity in comparison to dentin and enamel.

Assessment of a Synthetic Type IV Cast and a Resin Polyol Used in the Fabrication of Dental Models.

OBJECTIVE: To evaluate the dimensional changes, reproduction of details, and surface roughness of a type IV cast and a resin used to fabricate dental models. MATERIALS AND METHODS: Two commercial brands of materials were evaluated: a type IV synthetic cast (Fuji Rock) and a polyol resin (Novox). Twenty samples were obtained from polyvinyl siloxane molds that reproduced the surface of a metal master model standardized according to the American National Standards Institute/American Dental Association specification no. 19. The materials were used according to the manufacturer's instructions and divided into two groups (n = 10). Each mold was photographed immediately after molding and 1 hour after molding. The obtained models were also photographed and measurements were obtained by using Image J software. The paired t-test was used to compare the molding materials and one-way analysis of variance (ANOVA) was used to compare the dimensional changes between the groups at a significance level of 5%. RESULTS: Statistically significant differences were observed between the models fabricated with the polyol resin and type IV synthetic cast with regard to reproduction of surface details, surface roughness, and dimensional stability (p < 0.05), with the resin providing superior surface detail reproduction and greater dimensional accuracy. CONCLUSION: The polyol resin exhibited superior behavior regarding detail reproduction, surface roughness, and dimensional change compared with the type IV synthetic cast.

Association between Tooth Loss and Degree of Temporomandibular Disorders: A Comparative Study.

OBJECTIVE: The aim of this study was to evaluate the association between tooth loss and the signs and symptoms of temporomandibular disorders (TMDs). MATERIALS AND METHODS: One hundred fifty patients with an average age of 49.2 (±14.06) years were divided into three groups (n = 50/group) according to the degree of tooth loss: GI (dentate -control), GII (edentulous), GIII (partially dentate). After performing anamnesis and clinical examination, a questionnaire was used, so that the patients could fill in information on signs and symptoms of TMD. After analyzing this information, it was possible to classify the degree of severity of TMD. As age is a confounding variable to the level of TMD, an analysis of covariance (ANCOVA) was used to check for differences in the degree of TMD between groups (covariate = age). A post hoc test (Bonferroni) was performed to compare the groups two by two (5% significance level). RESULTS: The mean level of TMD according to the groups was GI - 1.95; GII - 2.15; GIII - 2.55. There were significant differences between the study groups (p > 0.05). A post hoc test (Bonferroni) confirmed the difference between edentulous patients and the other groups. CONCLUSION: The tooth loss is directly related to the signs and symptoms of TMD. The degree of TMD was significantly higher in edentulous patients.

Comparison of Antimicrobial Activity between Chemical Disinfectants on Contaminated Orthodontic Pliers.

AIM: To compare the antimicrobial activity of the chemical substances--70% isopropyl alcohol, 2% glutaraldehyde (GTA) and 0.25% peracetic acid (PAA) in disinfecting orthodontic pliers contaminated in vitro with Streptococcui mutani, Staphylococci aureui and Candida albicani. MATERIALS AND METHODS: Distal end cutter pliers were divided into five groups: group 1 (negative control--sterilized pliers), group 2 (positive control--sterilized plier, subsequently contaminated), group 3 (disinfected with 70% isopropyl alcohol, friction method), group 4 (disinfected with 2% GTA, immersion method for 30 minutes), group 5 (disinfected with 0.25% peracetic acid (PAA), immersion method for 10 minutes). After the pliers were treated with one disinfectant and submitted to microbiological evaluation (by counting colony forming units), they were submitted to the same cleansing, sterilizing and contaminating processes, and were used in the following groups (crossover and washout study). The two-factor analysis of variance (ANOVA) test, followed by the Tukey test, was used to compare the groups. RESULTS: The results showed that there was no statistically significant difference between the three tested disinfectants. CONCLUSION: Although there were no statistically significant differences between the disinfectants, the chemical agents 2% glutaraldehyde and 0.25% PAA were effective in inhibiting the growth of the three microorganisms tested; however, 70% isopropyl alcohol was unable to completely eliminate S. aureui. CLINICAL SIGNIFICANCE: The chemical substances 2% glutaraldehyde and 0.25% PAA completely eliminated the microorganisms tested.

Filling Material Bond Strength to Dentin Is Positively Influenced by the Agitation of Endodontic Final Irrigating Solutions.

Introduction: The final step of irrigation has been considered to of increase the bonding strength of filling material to dentin. This study investigated the impact of three final-step irrigation methods on the endodontic sealer bond strength to dentin by using a micro push-out test. Materials and Methods: Palatal roots of human maxillary molars were cleaned and shaped and randomly divided in six groups (n=15) according to the final-step irrigation method and the type of root canal sealer used. The solutions used for the final-step irrigation were 17% ethylenediaminetetraacetic acid and 2.5% sodium hypochlorite, which underwent three methods: 1) syringe-needle irrigation/conventional, 2) passive ultrasonic irrigation, and 3) XP-endo Finisher agitation. The root canal sealers used were: EndoSequence BC Sealer, and AH-Plus sealer. Roots were obturated with the single cone technique and then, cross-sectioned in 2-mm-thick slices (3 slices from each root). Push-out test was performed on the sliced specimens (cervical, middle, and apical thirds) with a universal testing machine. Bond strength values were recorded in megapascal (MPa). Subsequently, each specimen was longitudinally split to verify the type of failure. Data analysis was performed using Johnson transformation, three-way analysis of variance, Tukey's post-hoc tests, and the partial Eta squared test. Results: There were significant differences in bond strength between the sealers [AH: 4.46±2.24 and BC: 3.47±2.19 MPa (P<0.001)]; between final-step irrigation methods [passive ultrasonic irrigation: 4.52±2.25, XP-endo Finisher: 3.93±3.93 and syringe-needle irrigation/conventional: 3.37±2.51 MPa (P<0.001)], and between the root canal thirds represented by the sliced specimens [cervical: 5.45±2.39, middle: 4.14±1.99 and apical: 2.30±1.30 MPa (P<0.001)]. The interaction between the variables had no significance (P>0.05). Conclusion: Agitation of the final irrigating solution may improve the bonding of the sealer to canal walls. AH-Plus sealer had the highest bond strength. The bond strength reduced significantly towards the apical third.

Preoperative gingival conditioning as a guide for implant installation and to achieve proper dentogingival contours.

A successful esthetic outcome for implant-supported dentures depends on the careful manipulation of peri-implant tissue as well as the precise placement of the implant. In addition, careful surgical and prosthetic planning is essential for esthetically important areas, especially in partially edentulous cases. This study describes a clinical case that presented absent maxillary central incisors in which prior prosthetic planning was used to perform provisional restorations, that was used to condition the gingival tissues and guide implant installation. These procedures made it possible to achieve a dentogingival contour, interdental papillae, and an emergence profile in the edentulous area. The techniques outlined here proved to be sufficient and support the peri-implant tissues to create a more esthetic final prosthesis.

Influence of Application of Dimethyl Sulfoxide on the Bonding Properties to Eroded Dentin.

PURPOSE: To evaluate the effect of dimethyl sulfoxide (DMSO) on the microtensile bond strength (µTBS), nanoleakage (NL), and degree of conversion (DC) of universal adhesives on eroded dentin. MATERIALS AND METHODS: One hundred thirty-four extracted (134) human third molars were selected for the study. After the dentin surface was exposed, 128 teeth were randomly assigned to 16 experimental groups as follows: dentin surfaces (sound dentin and eroded dentin), application of DMSO (without or with the application of DMSO), and adhesive strategies (etch-and-rinse [ER] and self-etch [SE]). The universal adhesive systems iBond Universal (IBU) and Scotchbond Universal (SBU) were applied and the teeth were restored using a resin composite. After 24 h in distilled water at 37°C, the samples were sectioned and evaluated for µTBS. Selected sticks from each tooth were used for evaluating NL and DC. The remaining six teeth were used to measure the thickness of the collagen layer of the artificially eroded dentin using scanning electron microscopy. Data on µTBS, NL, and DC (%) were analyzed using three-way ANOVA and Tukey's test (α = 0.05). RESULTS: Significantly lower µTBS (p = 0.0001) and DC (p = 0.01) were observed for eroded dentin than for sound dentin. However, a significant increase in the µTBS (p = 0.0007) and DC (p = 0.001) was observed for both substrates when DMSO was applied. Moreover, the application of DMSO decreased the concentration of silver nitrate at the bottom of the hybrid layer for both sound and eroded dentin (p = 0.002). Eroded dentin showed enlarged tubules with the presence of a collapsed collagen fibril layer approximately 5.0 ± 2.0 mm of thickness. CONCLUSION: The bonding performance of both tested universal adhesives improved on both sound and eroded dentin with DMSO pretreatment.

Correlation between the Periapical Index and Lesion Volume in Cone-beam Computed Tomography Images.

INTRODUCTION: The study aimed to correlate the Periapical Index (PAI), obtained by way of periapical radiographs, with the volume of chronic periapical lesion, obtained through cone-beam computed tomography (CBCT), in the permanent teeth. METHODS AND MATERIALS: Radiographs and CBCT images were selected from 35 single-rooted permanent teeth, with fully formed apices, with a diagnosis of pulp necrosis and chronic apical periodontitis that was radiographically visible. Two independent raters evaluated the radiographs on two separate occasions and classified the periapical lesions in accordance with Ørstavik's PAI. The periapical lesion volume was calculated in the CBCT images. The correlation between the PAI and the lesion volume was calculated using Spearman's correlation test. RESULTS: There was a positive, moderate correlation between the PAI and the volume (rs=0.596; P<0.001) where rs2 is equal to 0.355, showing that only 35% of the PAI variation was dependent upon the variation in periapical lesion volume. CONCLUSION: The radiographic evaluation of the periapical lesion does not reflect the lesion's volumetric characteristics as the volume had a moderate effect on the choice of PAI score.

Exploring different photodynamic therapy parameters to optimize elimination of Enterococcus faecalis in planktonic form.

BACKGROUND: The failure of endodontic treatment is linked to the presence of Enterococcus faecalis in the root canals. The scope of this study was to evaluate the influence of the energy dose and frequency of photodynamic therapy (PDT cycles), as well as the volume of bacterial suspensions (BS) in the elimination of Enterococcus faecalis in planktonic form. METHODS: In four successive assays BS of Enterococcus faecalis ATCC 19433 were irradiated with a diode laser (40 mW) using the photosensitizer (PS) methylene blue (MB) (0.005 µg/mL). Group 1 - Effect of energy dose: 100 µâ€¯L of BS and 100 µâ€¯L of PS were irradiated by 1, 2.5, 5, 7.5 and 10 minute s. Group 2 - Effect of PDT cycles: The BS received 1, 2, 3 or 4 PDT cycles (in each cycle 100 m L of PS was added and irradiated by 2.5 minutes). Group 3 - Effect of energy dose and bacterial suspension volume: 10 µâ€¯L of BS and 10 µâ€¯L of PS were irradiated similar to group 1. Group 4 - Effect of energy dose, bacterial suspension volume and PDT cycles: 10 µâ€¯L of BS and 10 µL of PS were irradiated according to group 2. The laser source and MB isolated represented the controls. RESULTS: The mean log reduction after separate applying laser light and MB were 0.01 and 0.07, respectively. It was found that wells with 100 µâ€¯L of BS irradiated with 2.4 to 24 J of energy did not cause significant bacterial elimination (p > 0.05), on the other hand PDT cycles above 12 J increased significantly bacterial elimination (p < 0.05). In 10 µâ€¯L wells irradiation from 12 J of energy provided higher bacterial elimination (p < 0.05) which combined with PDT cycle resulted in the logarithmic elimination of E. faecalis (p < 0.05). CONCLUSIONS: The energy dose, the volume of the bacterial suspension and, especially, the PDT cycles optimized the bacterial elimination of Enterococcus faecalis in planktonic form.

Evaluation of several clinical parameters after bleaching with hydrogen peroxide at different concentrations: A randomized clinical trial.

OBJECTIVE: This randomized double-blind clinical trial compared tooth sensitivity (TS), bleaching efficacy, and cytokine levels after applying in-office bleaching treatments containing 15% and 35% hydrogen peroxide (HP15% and HP35%, respectively). METHODS: Twenty-five volunteers were randomly assigned to receive HP15% or HP35% treatment. The bleaching agent was applied in three 15-min applications per session. Two bleaching sessions were separated by a 1-week interval. The participants scored TS using a visual analog scale and numerical rating scale. Bleaching efficacy was determined by subjective and objective methods. Gingival crevicular fluid was collected from three jaws sites per patient for the analysis of fluid volume. Flow cytometry was used to analyze gingival crevicular fluid levels of interleukin (IL)-1ß, IL-2, IL-4, IL-6, IL-10, tumor necrosis factor, and interferon-gamma. All measurements were obtained before and after bleaching. All data were statistically analyzed (α=0.05). RESULTS: The absolute risk and intensity of TS was higher for HP35% than for HP15% (p>0.002). One month post-bleaching, HP35% produced more bleaching than HP15% (p=0.02). However patient perception (p=0.06) and patient satisfaction (p=0.53) with regard to bleaching were not significantly different. No significant differences existed in the gingival fluid volume (p>0.38) or in any cytokine level (p>0.05) for either HP concentration. CONCLUSION: Treatment: with HP35% is more effective than HP15%, but generates a greater risk and intensity of TS. No inflammatory changes occurred despite the difference in the HP concentrations. CLINICAL SIGNIFICANCE: Hydrogen peroxide at a lower concentration (e.g., 15%) should be considered a good treatment alternative for in-office bleaching because the higher concentration for in-office bleaching generates a greater risk and intensity of TS for patients.

Er:YAG pre-treatment for bonding of orthodontic bracket: 1 year of in vitro treatment.

OBJECTIVE: The aim of this study was to evaluate in vitro bond strength of metal brackets bonded with: total etch, total etch with erbium: yttrium aluminum garnet laser (Er:YAG) and self-etching adhesive systems, submitted to thermal-mechanical cycling, simulating 1 year of orthodontic treatment. MATERIALS AND METHODS: For the study, 80 bovine incisors were randomly divided into 3 experimental groups (n=16 each): XT- acid etching + Transbond XT, XT/Er:YAG- Transbond XT associated with Er:YAG laser irradiation (λ=2.94 µm, 60 mJ, 10 Hz) and SEP- Transbond Plus Self Etching Primer. Samples were submitted to thermal-mechanical cycling, simulating 1 year of orthodontic treatment. Afterward, the shear bond strength test was performed in a universal test machine at a speed of 0.5mm/min. Samples were evaluated under a stereomicroscope and by scanning electron microscopy for analysis of enamel surface and adhesive remnant index. Data were analyzed using Kruskal-Wallis and Mann-Whitney (with Bonferroni correction) statistical tests. RESULTS: Statistically significant difference was observed between the groups studied (p<0.05). Groups XT and SEP showed the highest bond strength values, without statistical difference between them, while group XT/Er:YAG showed reduction in bond strength values. Higher frequency of adhesive failures between enamel and adhesive system was verified for groups XT and XT/Er:YAG. CONCLUSION: The conventional (XT) and self-etching (SEP) adhesive systems showed mean bond strength values, similar between them, whereas the previous application of Er:YAG laser promoted the lowest bond strength values.

Effect of Anatomical Customization of the Fiber Post on the Bond Strength of a Self-Adhesive Resin Cement.

AIM: The aim of the study was to evaluate, by means of the push-out test, the effect of the anatomical customization of the fiber post on the bond strength of a self-adhesive resin cement. METHODS: Twelve endodontically treated, human, upper central incisors were randomly divided into two groups (n = 6): control (glass fiber posts cemented with Relyx® U200) and customized (glass fiber posts anatomically customized with translucent composite resin cemented with Relyx U200). The roots were sectioned into three slices, cervical, middle, and apical, and photographed with a digital camera attached to a stereomicroscopic loupe. The images were analyzed by software, for evaluation of the cement line. The slices were subsequently submitted to the push-out test until the post had completely extruded, and the fracture mode was analyzed with a stereomicroscopic loupe. RESULTS: The results showed significant differences between the groups in the different root thirds in relation to the area occupied by air bubbles (p < 0.05). Bond strength, when all the thirds are considered, was 8.77 ± 4.89 MPa for the control group and 16.96 ± 4.85 MPa for the customized group. CONCLUSION: The customized group showed greater bond resistance than the control group and a more uniform cement layer.

Factors Affecting the Periapical Status of Root-Filled Canals: A Cross-Sectional Study at the Undergraduate Level.

OBJECTIVE: The aim was to evaluate the influence of multiple factors on the periapical status of endodontically treated (ET) teeth. METHODS: The patients were clinically and radiographically reevaluated after root canal therapy. The quality of the root-filled canals, coronal restorations, intraradicular posts, dental caries, and periodontal parameters were associated with the teeth's periapical status. RESULTS: The 122 patients provided 154 ET teeth; 97.4% teeth were asymptomatic, and 75.5% had a normal periapical status. The percentage of perfect, satisfactory, and deficient root-filled canals was of the order of 41.6%, 46.1%, and 12.3%, respectively. The percentage of adequate and inadequate coronal restorations was 31.2% and 68.8%, respectively. A total of 14.9% teeth had intraradicular posts, and 29.2% had cavitated carious lesions in the dentin. Gingival bleeding was observed in 31.8% of teeth, and dental biofilm was visible in 58.4%. A total of 11.7% showed pathologic tooth mobility, and 22.1% teeth were diagnosed with periodontal disease. CONCLUSIONS: Carious lesions, gingival bleeding, and tooth mobility were significantly associated with the occurrence of periapical lesions in root-filled canals.

Photodynamic therapy with high-power LED mediated by erythrosine eliminates Enterococcus faecalis in planktonic forms.

BACKGROUND: The failure of endodontic treatment is linked to the presence of microorganisms, particularly Enterococcus faecalis, in the root canals. This study evaluated the effectiveness of photodynamic therapy (PDT) using erythrosine irradiated by a high-power curing light on a planktonic suspension culture of E. faecalis. METHODS: Bacterial suspensions of E. faecalis were adjusted and then mixed in a 1:1 proportion, in triplicate, in treatment groups by varying the length of irradiation time (120 and 240s) and the molarity of the erythrosine (5 and 10µM). In order to verify the post-treatment bactericidal effect, a count of the viable bacteria was performed (CFUmL-1) and transformed into Log10 CFU. The one-way ANOVA with Tukey post-hoc test was applied to check for differences between the groups. RESULTS: The bacteria were completely eradicated in the groups that used PDT with 5µM 240s, 10µM 120s and 10µM 240s (p≪0.001). The effect of the PDT 5µM 120s group was significant (p≪0.05) in comparison with the groups using only light or only erythrosine. Positive control (exposure to 2.5% NaClO for 120 and 240s) completely eradicated E. faecalis. The negative control (PBS) did not alter the quantities of E. faecalis CFU with 9.605 Log10 CFU at 120s and 9.621 Log10 CFU at 240s. CONCLUSION: PDT with erythrosine in a concentration of 10µM and high-power LED is capable of totally eliminating E. faecalis in planktonic suspension.

Regeneração óssea na região posterior da maxila para instalação de implantes dentários / Regeneración del hueso en la región posterior del maxilar para la instalación de implantes dentales / Bone regeneration in the posterior maxillary region for installation of dental implants

Introdução: regeneração óssea da região posterior da maxila, é um recurso importante para possibilitar a localização correta dos implantes e assim permitir uma adequada reabilitação protética. Várias técnicas cirúrgicas são relatadas, desde a forma de acesso ao seio, elevação da membrana de Schneider e preenchimento da cavidade. Objetivo: abordar os recursos que vem sendo utilizados na cirurgia de regeneração óssea da região posterior da maxila bem como a efetividade dos métodos aplicados. Métodos: foi realizada uma busca eletrônica da literatura, nas bases de dados LILACS, MEDLINE e BBO de estudos publicados na língua inglesa e portuguesa. Como critérios de inclusão foram considerados artigos entre o ano 2000 e 2014, sendo que as palavras chaves que orientaram a busca foram: maxillary bone regeneration, Schneiderian membrane, maxillary sinus lift. Foram obtidos 1 529 artigos, dos quais selecionados 27 artigos relevantes para o estudo em questão. Como critérios de exclusão foram eliminados artigos no qual se encontravam no ano abaixo de 2008 e que fugiam do assunto em questão. Análises e integração da informação : encontrou-se que a técnica tradicional de acesso ao seio maxilar com uso de brocas, elevação da membrana, por meio de curetas, e a regeneração propriamente dita com enxerto ósseo autógeno e/ou heterógeno continuam como as mais utilizadas, no entanto alternativas menos invasivas como tecnologia ultrassônica para fazer acesso, hidrodissecção para elevar a membrana Schneider e biomateriais para preencher a cavidade surgem como opções viáveis e com resultados favoráveis. Conclusões: existe um direcionamento na busca por métodos e materiais que diminuam a morbidade da técnica tradicional e que ofereçam resultados satisfatórios a curto e a longo prazo. A utilização de técnicas cirúrgicas menos invasivas e uso de biomateriais estão entre os avanços para a regeneração da região posterior da maxila(AU)

Introducción: la regeneración ósea de la región posterior del maxilar es un procedimiento importante que permite la correcta colocación de los implantes dentales y una adecuada rehabilitación protésica. Se describen varias técnicas quirúrgicas que van desde la forma de acceder al seno maxilar, el levantamiento de la membrana de Schneider hasta el relleno de la cavidad. Objetivo: abordar los recursos utilizados en la cirugía de regeneración ósea de la zona posterior del maxilar y la efectividad de los métodos aplicados. Métodos: se realizó una revisión bibliográfica en las bases de datos LILACS, MEDLINE y BBO en busca de estudios publicados en inglés y portugués. El criterio de inclusion abarcó los artículos publicados entre los años 2000 y 2014 y las palabras claves que orientaron la búsqueda fueron: regeneración del hueso maxilar, membrana de Schnneider y elevación del seno maxilar. Se encontraron 1 529 artículos de los cuales se seleccionaron 27 con contenido relevante para el estudio en cuestión. En cuanto a los criterios de exclusion, se eliminaron los artículos publicados antes del 2008 y que no se asociaban mucho con el tema referido. Análisis e integración de la información: se halló que la técnica tradicional de acceso al seno maxilar con el uso de brocas, el levantamaiento de la membrana de Schnneider por medio de curetas y la regeneración como tal mediante injertos óseos autógenos y/o heterógenos siguen siendo los procedimientos más utilizados. Por otra parte, alternativas menos invasivas como la tecnología del ultrasonido para lograr acceso, la hidrodisección para levantar la membrana de Schneider y el empleo de biomaterials para rellenar la cavidad emergen como opciones viables con resultados alentadores. Conclusiones: existe una orientación hacia la búsqueda de métodos y materials que disminuyan la morbilidad de las técnicas tradicionales y ofrezcan resultados satisfactorios a corto y a largo plazos. Las técnicas quirúrgicas menos invasivas y el uso de los biomateriales se encuentran entre los avances de hoy día para la regeneración de la zona posterior del maxilar(AU)

Introduction: bone regeneration of the posterior maxilla is an important feature to enable correct placement of implants and thus allow an adequate prosthetic rehabilitation. Several surgical techniques are reported, since the form of access to the sinus, elevation of Schneider membrane and fill the cavity. Objective: to address the resources used in bone regeneration surgery of the posterior maxilla and the effectiveness of the methods applied. Methods: an electronic search of the literature was performed in the databases LILACS, MEDLINE and BBO studies published in English and Portuguese. The inclusion criteria were considered articles between 2000 and 2014, with the key words that guided the search were: maxillary bone regeneration, Schneiderian membrane, maxillary sinus lift. 1 529 articles were obtained, of which 27 selected articles relevant to the study. Exclusion criteria were eliminated in the articles which were in the year below 2008 and fleeing the matter at hand. Data analysis and integration: it was found that the traditional technique of access to the maxillary sinus with the use of drills, lifting the membrane through curettes, and the regeneration itself with autogenous bone graft and/or heterogeneous continue as the most commonly used, however alternative as less invasive ultrasonic technology to access, hydrodissection to raise the Schneider membrane and biomaterials to fill the cavity emerge as viable, with favorable results options. Conclusions: there is a direction in the search for methods and materials that reduce the morbidity of traditional techniques and which offer satisfactory results in the short and long term. The use of surgical techniques less invasive and use of biomaterials are among the advances for the regeneration of the posterior maxilla(AU)

Effect of cyclic load on vertical misfit of prefabricated and cast implant single abutment

OBJECTIVES: The purpose of this in vitro study was to evaluate misfit alterations at the implant/abutment interface of external and internal connection implant systems when subjected to cyclic loading. MATERIAL AND METHODS: Standard metal crowns were fabricated for 5 groups (n=10) of implant/abutment assemblies: Group 1, external hexagon implant and UCLA cast-on premachined abutment; Group 2, internal hexagon implant and premachined abutment; Group 3, internal octagon implant and prefabricated abutment; Group 4, external hexagon implant and UCLA cast-on premachined abutment; and Group 5, external hexagon implant and Ceraone abutment. For groups 1, 2, 3 and 5, the crowns were cemented on the abutments and in group 4 crowns were screwed directly on the implant. The specimens were subjected to 500,000 cycles at 19.1 Hz of frequency and non-axial load of 133 N in a MTS 810 machine. The vertical misfit (μm) at the implant/abutment interface was evaluated before (B) and after (A) application of the cyclic loading. Data were analyzed statistically by using two-away ANOVA and Tukey's post-hoc test (p<0.05). RESULTS: Before loading values showed no difference among groups 2 (4.33±3.13), 3 (4.79±3.43) and 5 (3.86±4.60); between groups 1 (12.88±6.43) and 4 (9.67±3.08), and among groups 2, 3 and 4. However, groups 1 and 4 were significantly different from groups 2, 3 and 5. After loading values of groups 1 (17.28±8.77) and 4 (17.78±10.99) were significantly different from those of groups 2 (4.83±4.50), 3 (8.07±4.31) and 5 (3.81±4.84). There was a significant increase in misfit values of groups 1, 3 and 4 after cyclic loading, but not for groups 2 and 5. CONCLUSIONS: The cyclic loading and type of implant/abutment connection may develop a role on the vertical misfit at the implant/abutment interface.

Effect of silica coating and silanization on flexural and composite-resin bond strengths of zirconia posts: An in vitro study.

STATEMENT OF PROBLEM: The bond strength of composite resin cores to the smooth surface of prefabricated zirconia-based ceramic posts is problematic because it might not be sufficient to ensure stability of the post-and-core system. It is also not clear whether any alteration of the post surface to provide additional mechanical or chemical retention would compromise flexural strength of the posts. PURPOSE: This study tested the effect of a tribochemical treatment on the bond strength (BS) between zirconia-based ceramic posts and composite resin and on the flexural strength (FS) of the posts. MATERIAL AND METHODS: For the BS test, 2 groups of specimens (n = 10) were prepared as follows: In the experimental (E) group, zirconia-based ceramic posts (Cosmopost), 21 mm long and 1.7 mm in diameter, were treated with a tribochemical silica coating and silanization system (Rocatec). For the control (C) group, zirconia-based ceramic posts were used as supplied by the manufacturer. For the 2 groups, posts were centered and vertically positioned in a metal mold, and composite resin (Tetric Ceram) was polymerized around the posts to form rings (6 mm diameter x 4 mm height). All specimens were positioned in a universal testing machine, and a load was applied axially on the protruding heads of posts in a shear push-out mode test until bond failure (MPa). Fracture mode was assessed as cohesive, cohesive/adhesive, or adhesive. Following this, the FS of the posts was measured in MPa using a 3-point bending test. Data were recorded and statistically analyzed using the Student t test for both tests (alpha = .01). RESULTS: Mean fracture load values +/- SDs for the BS test were 28.1 +/- 2.3 MPa and 8.9 +/- 3.97 MPa for the E and C groups, respectively. The mean FS values were 1544.9 +/- 214.1 MPa and 844.8 +/- 50.8 MPa for the E and C groups, respectively. The tribochemically treated posts exhibited significantly higher values for both bond strength to composite resin and resistance to fracture when compared to posts in the control group (P < .001). Fracture analysis showed 100% cohesive/adhesive fractures for group E specimens and 100% adhesive fractures for group C specimens. CONCLUSIONS: The use of a tribochemical silica coating process and silanization on zirconia-based ceramic posts increased both the bond strength to composite resin as well as the fracture strength of posts.

Effect of cyclic loading on fracture strength of endodontically treated teeth restored with conventional and esthetic posts.

INTRODUCTION: Esthetic post and core systems were recently introduced. There are few reports regarding their behavior under cyclic loading. OBJECTIVES: This study compared the effect of cyclic loading on survival rate, residual strength and mode of fracture of endodontically treated teeth restored with esthetic and direct metallic post systems subjected to mechanical cyclic loading. MATERIALS AND METHODS: Thirty canines were endodontically treated, decoronated and prepared for metal free ceramic crowns, leaving 1.5 mm of dentin for ferrule effect. They were distributed in 3 groups and restored as follows: group 1 with zirconia posts (Cosmopost) and glass-ceramic cores (IPS Empress Cosmopost); group 2 with fiber reinforced composite posts (FibreKor) and group 3 with titanium posts (AZthec Anchor). Direct resin composite (Build It FR Resin Composite) was used as core in groups 2 and 3. All specimens were restored with all ceramic crowns (IPS Empress 2). A resin cement/adhesive system (Cement It/Bond It Primer A+B) was used to lute the posts to root canals and metal free porcelain crowns to the teeth preparation. Specimens were subjected to mechanical load of 250 N for 500,000x at a frequency of 1.7 Hz and then to static load until failure in a universal testing machine. Data were analyzed using One-way ANOVA and Fischer Exact tests alpha=0.05. RESULTS: All groups had 100% survival rate after cyclic loading; fracture strength values (SD) in N were: group 1 = 886.5(170.6), group 2 = 762.2(113.6) and group 3 = 768.9(72.9); there was no difference among groups (p=0.08); the percentage of mode of favorable fracture found was: group 1 = 60%, group 2 = 90% and group 3 = 50%; there was no correlation between the mode of failure and post and core system used (P=0.142). CONCLUSIONS: Esthetic post and core systems showed statistically equivalent fracture strength values, mode of failure and survival rate compared to conventional direct metallic post and resin composite core system after cyclic loading.