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.

Personality traits, psychosocial effects and quality of life of patients submitted to dental bleaching.

BACKGROUND: Perception is defined as the ability to distinguish through the senses. All perception is dependent on factors such as personality, previously lived experiences and cultural elements. When planning an aesthetic treatment, consider the way the patients perceive the changes and outcomes is essential for reaching their expectations. The objective of this study was to assess if there was predominance of a personality trait of patient undergoing dental bleaching and if this treatment could promote changes in this traits, in the psychosocial impact and quality of life of these individuals. METHODS: The assessment of personality characteristics, quality of life, psychosocial and self-perception was a cross-sectional observational study and it was carried out by applying questionnaires to 55 patients that were submitted to a clinical phase. The psychometric instruments used were NEO FFI-R (personality), PIDAQ (psychosocial effect) and WHOQOL-BREF (quality of life). Each test domain was prior and after bleaching by Wilcoxon Signed Rank test (α = 0.05). The internal consistencies of each scale were evaluated by Cronbach's alpha. RESULTS: No statistical significant differences among personality traits means were observed among participants but there was predominance of two predominant personality traits in this study: conscientiousness (45.5%) and extraversion (34.5%). In four test domains of the PIDAQ, significant differences were observed before and after dental bleaching. The overall perception of the PIDAQ was also statistically significant demonstrating an improvement. There were no differences on overall or specific domains scores of the WHOQOL before and after treatment. CONCLUSIONS: Subjects who underwent dental treatment improved their self-confidence and reduced concerns about dental aesthetics, social and personality impact of dental alterations. TRIAL REGISTRATION: This study was conducted in parallel to a clinical investigation that aimed to evaluate tooth sensitivity related to dental bleaching technique and registered in REBEC clinical registry under protocol RBR-6pt2n3 in 13 November 2013.

Influence of the geometry of the screwdriver-screw connection on the reverse torque of UCLA screws.

The aim of this study was to evaluate the influence of the geometry of the screwdriver-screw connection on the reverse torque of UCLA screws after repeated cycles of tightening and loosening in an implant-supported prosthesis. Thirty sets of external hex titanium implants, UCLA abutments, and UCLA abutment screws were divided into 3 experimental groups (n = 10). In the square group, the implant and UCLA abutment system were mounted in an upright position using a screw with a square screwdriver-screw connection. In the hexagonal group, the implant and UCLA abutment system were mounted in an upright position using a screw with a hexagonal screwdriver-screw connection. In the hexalobular group, the implant and UCLA abutment system were mounted at 70° using a dynamic UCLA abutment and screw with a hexalobular screwdriver-screw connection. Ten alternating torque-reverse torque cycles were applied to each screw using a screwdriver fixed at the end of a digital torque meter. The screws with a square connection resulted in less loss of reverse torque than the other types. Screws with a hexagonal connection showed a statistically significant loss of torque initially but remained constant for the remaining cycles. For the screws with a hexalobular connection, the loss of torque was greater, and substantial deformation of the plastic in the microstructure was noted. The screwdriver-screw connection geometry had a direct influence on the reverse torque of UCLA screws, and the initial reverse torque of the abutment screws with a square connection was greater than that of the hexagonal and hexalobular designs.

Improving bonding to eroded dentin by using collagen cross-linking agents: 2 years of water storage.

OBJECTIVES: The aim of this study was to investigate the effects of collagen cross-linking agents on nanomechanical and bonding properties of eroded dentin (ED), 24 h and 2 years after water storage. MATERIALS AND METHODS: Human molar dentin surfaces, eroded by soft drinks or citric acid, were acid-etched and treated with primers containing proanthocyanidin (PA) and riboflavin (RI) or were untreated (control) and tested after 24 h and 2 years. After acid etching and adhesive application (Prime&Bond Elect (PBE); Scotchbond Universal (SBU); Tetric n-bond Universal (TEU)), specimens were sectioned into beams and tested for microtensile bond strength (µTBS) and silver nitrate deposition (NL) after 24 h and 2 years. The beams were used to evaluate the 24-h in situ conversion of degree (DC). Nanohardness (NH) and Young's modulus (YM) were evaluated via resin-bonded dentin slices after 24 h and 2 years. A three-way ANOVA and Tukey's test were used for statistical analysis (5%). RESULTS: For both storage times, ED with citric acid resulted in lower µTBS, NH, and YM and higher NL for each adhesive system than soft drink ED (p < 0.05). After 2 years of water storage, cross-linking primers maintained the µTBS, NH, and YM (p < 0.05) when compared with the control group. Althougth, the NL values decreased for all groups after 2 years of water storage, PA and RI treatments showed NI values lower than control group (p < 0.001). No significant differences were observed between PA and RI treatments (p > 0.05). Cross-linking primers maintain or improve DC (p < 0.03). In general, TEU and SBU yielded higher µTBS, DC, NH, and YM and lower NL than PBE. CONCLUSION: Cross-linking agents improved the results and maintained the resin-ED interface bonding and nanomechanical properties, without jeopardizing adhesive polymerization. CLINICAL RELEVANCE: Cross-linking agents are a viable alternative for improving and maintaining resin-ED interface bonding and nanomechanical properties.

Co-Loaded Curcumin and Methotrexate Nanocapsules Enhance Cytotoxicity against Non-Small-Cell Lung Cancer Cells.

Background: As part of the efforts to find natural alternatives for cancer treatment and to overcome the barriers of cellular resistance to chemotherapeutic agents, polymeric nanocapsules containing curcumin and/or methotrexate were prepared by an interfacial deposition of preformed polymer method. Methods: Physicochemical properties, drug release experiments and in vitro cytotoxicity of these nanocapsules were performed against the Calu-3 lung cancer cell line. Results: The colloidal suspensions of nanocapsules showed suitable size (287 to 325 nm), negative charge (-33 to -41 mV) and high encapsulation efficiency (82.4 to 99.4%). Spherical particles at nanoscale dimensions were observed by scanning electron microscopy. X-ray diffraction analysis indicated that nanocapsules exhibited a non-crystalline pattern with a remarkable decrease of crystalline peaks of the raw materials. Fourier-transform infrared spectra demonstrated no chemical bond between the drug(s) and polymers. Drug release experiments evidenced a controlled release pattern with no burst effect for nanocapsules containing curcumin and/or methotrexate. The nanoformulation containing curcumin and methotrexate (NCUR/MTX-2) statistically decreased the cell viability of Calu-3. The fluorescence and morphological analyses presented a predominance of early apoptosis and late apoptosis as the main death mechanisms for Calu-3. Conclusions: Curcumin and methotrexate co-loaded nanocapsules can be further used as a novel therapeutic strategy for treating non-small-cell lung cancer.

Bonding Performance of Universal Adhesives to Eroded Dentin.

PURPOSE: To evaluate the microtensile bond strength (µTBS) and nanoleakage (NL) of several universal adhesives to eroded dentin (ED), using etch-and-rinse (ER) or self-etch (SE) strategies, and to characterize the surface using two pH cycling models to erode dentin (citric acid and a soft drink). MATERIALS AND METHODS: Molars were eroded either by soft-drink or citric acid cycling, or were left untreated as control (SD). For each surface, the following adhesives were applied: 1. All-Bond Universal; 2. Ambar Universal; 3. Clearfil Universal; 4. Futurabond U; 5. One Coat 7 Universal; 6. Peak Universal Bond; 7. Prime&Bond Elect; 8. Scotchbond Universal; 9. Tetric n-bond Universal, and 10. Xeno Select. After application of the composite, specimens were sectioned into composite-dentin sticks and tested under tension (0.5 mm/min). Selected sticks from each tooth were used to assess NL. The occlusal dentin surfaces after erosive cycling were examined using SEM. Data were analyzed by three-way ANOVA and Tukey's post-hoc test (a = 0.05). RESULTS: In ED, there was no difference in µTBS and NL between ER and SE strategies (p > 0.61). Most µTBS and NL values obtained for ED were, respectively, lower and higher than those for SD (p < 0.01), being worse for citric acid ED (p < 0.001). Citric-acid-eroded dentin showed more enlarged tubules, with partial loss of peritubular dentin when compared to soft-drink eroded dentin. CONCLUSION: The different pH cycling models reduced µTBS and increased NL of the composite/eroded-dentin interface; however, in ED, the performance of the universal adhesives did not depend on the adhesive strategy used.

Acid Etching with Modified Phosphoric Acid to Increase the Longevity of the Bonded Interface.

PURPOSE: To evaluate the effect of three phosphoric acids modified with chlorhexidine (CHX), benzalkonium chloride (BAC), or proanthocyanidins (PRO) and one conventional phosphoric acid (CON) on the immediate (24 h; IM) and 1-year composite-dentin microtensile bond strength (µTBS) and nanoleakage (NL), using an etch-and-rinse adhesive. MATERIALS AND METHODS: A flat dentin surface was exposed on 28 caries-free extracted molars, which were then randomly assigned to four groups (n = 7). After etching and rinsing with one phosphoric acid per group, the adhesive (Adper Single Bond 2) was applied on a moist dentin surface. Composite buildups (Filtek Z350) were constructed incrementally and bonded stick specimens (0.8 mm2) were prepared and submitted to the microtensile test (0.5 mm/min) immediately (24 h) or after 1 year of water storage. For nanoleakage, 2 bonded sticks from each tooth at each storage period were immersed in 50 wt% ammoniacal silver nitrate, polished, and analyzed by SEM in backscattered mode. Data were submitted to a two-way ANOVA and Tukey's test (α = 0.05). RESULTS: After 1 year, stable µTBS values were observed only for the modified phosphoric acids (CHX, BAC, and PRO). Also, NL was more evident in the CON group than in the CHX, BAC and PRO groups (p < 0.05) after 1-year water storage. CONCLUSIONS: Compared to the control, the phosphoric acid etchants which contained protease inhibitors (CHX, BAC and PA) promoted the stability of composite-dentin microtensile bond strength and showed less nanoleakage after 1 year of water storage. They represent an effective way of prolonging the stability of the composite-dentin bonds without creating an additional bonding step.

Two-Year Follow-up of Multidisciplinary Treatment Using Digital Smile Design as a Planning Tool for Esthetic Restorations on Maxillary Midline Diastema.

One of the challenges posed by diastema closure treatment in the presence of tooth size discrepancy is to achieve adequate distribution of the spaces between the teeth. The use of the Digital Smile Design can assist the clinician in visualizing and measuring dentogingival discrepancies with maximum predictability. The present clinical case describes an approach to space distribution with assistance of the digital tool, allowing adequate restorative procedures. The protocol used was shown to be efficient, achieving the esthetics desired by the patient both during and after multidisciplinary treatment, as well as having adequate stability.

Evaluation of Bond Strength, Marginal Integrity, and Fracture Strength of Bulk- vs Incrementally-filled Restorations.

PURPOSE: This study evaluated the effect of application technique and preparation size on the fracture strength (FS), microtensile bond strength (µTBS) and marginal integrity (MI) of direct resin composite restorations. MATERIALS AND METHODS: Conservative (5 × 2 × 2 mm) or extended (5 × 4 × 2 mm) preparations below the cementoenamel junction were performed in 140 human maxillary premolars (n = 70 per group). After adhesive application (XP Bond), half of each group was restored with the bulk technique (one 4-mm increment of Surefill SDR Flow plus one 1-mm horizontal capping layer of TPH3 [Spectrum TPH3 resin composite]) and half incrementally (TPH3 in three horizontal incremental layers, 1.5 to 2 mm each), all using a metal matrix band. After storage (24 h at 37°C), the proximal surfaces of each tooth were polished with Sof-Lex disks. For FS measurement, 60 restorations were mounted in a universal testing machine and subjected to a compressive axial load applied parallel to the long axis of the tooth, running at a crosshead speed of 0.5 mm/min. For µTBS testing, 40 teeth were longitudinally sectioned to obtain resin-dentin bonded sticks from the cavity floor (bonded area: 0.8 mm2). Specimens were tested in tension at 0.5 mm/min. The external marginal integrity of both proximal surfaces was analyzed using SEM of epoxy resin replicas. The µTBS, marginal integrity, and fracture resistance data were subjected to two-way ANOVA, and Tukey's post-hoc test was used for pair-wise comparisons (a = 0.05). RESULTS: Fracture resistance, microtensile bond strength, and marginal integrity values were not statistically significantly affected by application technique or preparation size (p = 0.71, p = 0.82, and p = 0.77, respectively). CONCLUSIONS: The use of a bulk-fill flowable composite associated with a conventional resin composite as a final capping layer did not jeopardize the fracture strength, bond strength to dentin, or marginal integrity of posterior restorations.

Five-year Effects of Chlorhexidine on the In Vitro Durability of Resin/Dentin Interfaces.

PURPOSE: To evaluate the effect of an acid containing 2% chlorhexidine (Ac/CHX) or a 2% CHX aqueous solution (Aq/CHX) on the immediate and 5-year bonding properties of resin/dentin interfaces produced by two adhesives. The presence of CHX in these interfaces was also evaluated under micro-Raman spectroscopy. MATERIALS AND METHODS: Forty-two molars were ground to expose a flat dentin surface. In the control group, the surfaces were etched with conventional phosphoric acid, and Prime&Bond NT (PB) and Adper Single Bond 2 (SB) were applied. In Ac/CHX, an acid containing 2% CHX was applied after adhesive application. In the Aq/CHX group, an aqueous solution of 2% CHX was applied for 60 s after etching. After placing the restoration, specimens were prepared and tested using the microtensile bond strength test (µTBS, 0.5 mm/min) immediately or after 5 years. For nanoleakage (NL), specimens at each period were immersed in silver nitrate solution and examined by EDX-SEM. In addition, specimens at each period underwent examination for CHX using micro-Raman spectroscopy. Data were submitted to appropriate statistical analysis (a=0.05). RESULTS: After 5 years, NL was more pronounced in the control than in the Ac/CHX or Aq/CHX (p<0.001). Significant reductions in the µTBS were observed for all groups; however, they were more pronounced for the control (p<0.001). CHX was still present in the hybrid layers Ac/CHX or Aq/CHX groups after 5 years. CONCLUSION: The use of a 2% chlorhexidine-containing acid or the application of an aqueous CHX primer may increase the long-term stability of resin/dentin interfaces.

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.

Shear Bond Strength of Orthodontic Brackets Fixed with Remineralizing Adhesive Systems after Simulating One Year of Orthodontic Treatment.

The objective of this study is to assess, in vitro, the shear bond strength of orthodontic brackets fixed with remineralizing adhesive systems submitted to thermomechanical cycling, simulating one year of orthodontic treatment. Sixty-four bovine incisor teeth were randomly divided into 4 experimental groups (n = 16): XT: Transbond XT, QC: Quick Cure, OL: Ortholite Color, and SEP: Transbond Plus Self-Etching Primer. The samples were submitted to thermomechanical cycling simulating one year of orthodontic treatment. Shear bond strength tests were carried out using a universal testing machine with a load cell of 50 KgF at 0.5 mm/minute. The samples were examined with a stereomicroscope and a scanning electron microscope (SEM) in order to analyze enamel surface and Adhesive Remnant Index (ARI). Kruskal-Wallis and Mann-Whitney (with Bonferroni correction) tests showed a significant difference between the studied groups (p < 0.05). Groups XT, QC, and SEP presented the highest values of adhesive resistance and no statistical differences were found between them. The highest frequency of failures between enamel and adhesive was observed in groups XT, QC, and OL. Quick Cure (QC) remineralizing adhesive system presented average adhesive resistance values similar to conventional (XT) and self-etching (SEP) adhesives, while remineralizing system (OL) provided the lowest values of adhesive resistance.

Toothpaste prevents debonded brackets on erosive enamel.

UNLABELLED: This study evaluated the effect of high fluoride dentifrice on the bond strength of brackets after erosive challenge. Eighty-four enamel specimens were divided into seven groups (n = 12): WN (distilled water/no acid challenge), W3C (distilled water/3 cycles of acid challenge), and W6C (distilled water/6 cycles of acid challenge) were not submitted to dentifrice treatment. Groups RF3C (regular fluoride dentifrice/3 cycles of acid challenge) and RF6C (regular fluoride dentifrice/6 cycles of acid challenge) were treated with dentifrices containing 1450 µg F(-)/g and HF3C (high fluoride dentifrice/3 cycles of acid challenge) and HF6C (high fluoride dentifrice/6 cycles of acid challenge) were with 5000 µg F(-)/g. Acid challenges were performed for seven days. After bond strength test, there was no significant difference among groups submitted to 3 cycles of acid challenge (P > 0.05). Statistically significant difference was found between the regular and high fluoride dentifrices after 6 cycles of acid challenge (<0.05). Similar areas of adhesive remaining were found among control groups and among groups W6C, RF3C, RF6C, HF3C, and HF6C. The high fluoride dentifrice was able to prevent the reduction of bond strength values of brackets submitted to acid challenge. CLINICAL RELEVANCE: the high fluoride toothpaste prevents debonded brackets on erosive enamel.

Sealing ability of root-end filling materials.

BACKGROUND: The aim of this research was to compare the apical sealing ability of different root-end filling materials (SuperEBA(®), ProRoot MTA(®), thermoplasticized gutta-percha + AH-Plus(®), thermoplasticized RealSeal(®)), by means of microbial indicators. MATERIALS AND METHODS: Thus, 50 human single-rooted teeth were employed, which were shaped until size 5 0, retro - prepared with ultrasonic tips and assigned to 4 groups, retro-filled with each material or controls. A platform was employed, which was split in two halves: upper chamber-where the microbial suspension containing the biological indicators was introduced (E. faecalis + S. aureus + P. aeruginosa + B. subtilis + C. albicans); and a lower chamber containing the culture medium brain, heart influsion, where 3 mm of the apical region of teeth were kept immersed. Lectures were made daily for 60 days, using the turbidity of the culture medium as indicative of microbial contamination. Statistical analyses were carried out at 5% level of significance. RESULTS: The results showed microbial leakage at least in some specimens in all of the groups. RealSeal(®) has more microbial leakage, statistically significant, compared to ProRoot(®) MTA and SuperEBA(®). No significant differences were observed when compared ProRoot(®) MTA and SuperEBA(®). The gutta-percha + AH Plus results showed no statistically significant differences when compared with the other groups. CONCLUSIONS: All the tested materials showed microbial leakage. Root-end fillings with Super-EBA or MTA had the lowest bacterial filtration and RealSeal shows highest bacterial filtration.

Chemical and structural characterization of glass ionomer cements indicated for atraumatic restorative treatment.

Glass ionomer cements (GICs) are restorative materials, which clinical use has increased significantly during the last decade. The aim of the present study was to analyze the chemical constitution and surface morphology of four glass ionomer cements: Maxxion R, VitroFill, Vidrion R and Vitremer. Twelve polyethylene tubes with an internal diameter of 3 and 3 mm in length were prepared, filled and then transferred to a chamber with 95% relative humidity and a temperature of 37°C. The surface morphology of the tested materials was examined by scanning electron microscopy (SEM) and main components were investigated by energy-dispersive X-ray microanalysis (EDX). Scanning electron microscopy revealed irregular and rough external surface. Cracking was not observed. The main constituents were found to be aluminum, silicon, calcium, sodium and fluoride. Phosphorus, sulfur and barium were only observed in Vidrion R, while chlorine were only observed in Maxxion R. Elemental mapping of the outer surface revealed high concentration of aluminum and silicon. Significant irregularities on the surface of the tested materials were observed. The chemical constitution of all GIC was similar.

Semidirect Restorations in Multidisciplinary Treatment: Viable Option for Children and Teenagers.

Due to the esthetic necessity required nowadays, the multidisciplinary treatment became a fundamental step in the restoration success. When the patient exhibits dental agenesis of one or more elements, he can show difficulty in social interactions. The age of the patient is a limiting factor to esthetic procedures, however, it should be evaluated as a real indicative with each case. The utilization of semi-direct restorations is a viable option due the cost, esthetic and improvement of physical and mechanical properties. The purpose of this paper is to present a case detailing the confection and cementation of anterior semi-direct restorations aimed at an anatomic reestablishment associated with integrated treatment with periodontics and orthodontics.

Multidisciplinary Treatment of a Fenestration-type Defect.

The case report aimed at treating a fenestration-type defect with multidisciplinary conventional and advanced surgical techniques. Fenestrations are isolated areas in which the exposed root surface is covered only by the periosteum and gingiva, but the remaining cortical bone remains intact. Root coverage is indicated in cases of root hypersensitivity, treatment of shallow caries lesions, cervical abrasions, and esthetic and cosmetic needs. In this case report, after proper hygiene instruction and dental biofilm control, a fenestration-type defect was treated using guided tissue regeneration (anorganic bovine matrix and resorbable membrane) and a connective tissue grafts, associated to an endodontic apicoectomy. After reevaluation, the remaining gingival recession was treated with a second gingival connective tissue graft covered with q double papillae type in order to reconstruct the periodontal tissues of the involved tooth. In this clinical case, the interaction between the different areas of dentistry has made it possible to correct a fenestration-type defect, following procedures based on scientific evidence, restoring periodontal health, esthetics, self-esteem, and meeting the patient's expectations regarding her initial complaint. This case report shows the important role of interdisciplinary approach to treating a patient with a complex periodontal defect that required different types of knowledge and abilities to achieve the best results based on the current status of dentistry possibilities.

Effect of Carbamide Peroxide on the Push-out Bond Strength of Different Composition Glass-Ionomer Cement to Root Canal Dentin when used as Cervical Barrier.

AIM: To evaluate the effect of 37% carbamide peroxide on the bond strength of conventional or resin-modified glass-ionomer cements when used as a cervical barrier in endodontically-treated teeth. MATERIALS AND METHODS: After root canal instrumentation and obturation, 40 specimens of the cement-enamel junction were obtained after transversal root canal sectioning from human extracted canines. The root canal specimens were standardized and filled with the following materials (n = 10, each group): G1: zinc phosphate (control), G2: Ketac glass-ionomer, G3: vitrebond glass-ionomer or G4: GC GL glass-ionomer. After 24 hours, the specimens were subjected to an application of 37% carbamide peroxide for 21 days, changed each 7 days and stored in an artificial pulp chamber. The specimens were then submitted to push-out bond strength testing with an electromechanical test machine (EMIC) and the failure mode in each specimen was analyzed with confocal microscopy (LEXT). RESULTS: G3 and G4 showed higher bond strengths values than the other groups (p < 0.05), and were similar to each other (p > 0.05). G1 showed the lowest bond strength value (p < 0.05). CONCLUSION: Glass-ionomer cements showed higher bond strength values than the zinc phosphate cement, and resin-modified glass-ionomer cements presented the highest push-out values to root canal dentin (GC, GL and Vitrebond). CLINICAL SIGNIFICANCE: Glass ionomer cements are recommended to use as cervical barrier materials before the internal dental bleaching, but its efficiency is questionable.

Differential Diagnosis and Treatment Proposal for Acute Endodontic Infection.

The objective of this study was to describe the main lesions that simulate clinically and propose a treatment protocol for acute endodontic infection. Signs and clinical symptoms of periodontal abscess, gingival abscess, odontoma, herpes simplex, pericoronitis, acute pulpitis and necrotizing ulcerative gingivitis/periodontitis (NUG/NUP) were described and compared with acute endodontic infections. A treatment protocol was described by optimizing the procedures in access cavity, microbial decontamination and detoxification of the root canal, apical debridement, intracanal and systemic medication and surgical drainage procedures. The convenience of the use of 5.25% sodium hypochlorite, root canal instrumentation using a crown-down technique, intracanal medication with 2% chlorhexidine or triple antibiotic paste and the convenience of the use of antibiotics, analgesics, and surgical drainage to solve cases of acute dentoalveolar abscess was discussed.

Nd:YAG Laser to obtain Irregularities on the Inner Surface of Porcelain.

AIM: The aim of this study was to evaluate the inner surface of two ceramic systems: IPS Empress II (Ivoclar Vivadent, Germany) and In-Ceram Alumina (Vita Zahnfabrick, Germany) submitted to surface treatments, especially by Nd:YAG laser. MATERIALS AND METHODS: Fifty samples were prepared in pellet form for each ceramic system according to manufacturers' specifications. The samples were stored at room temperature and then be subjected to surface treatment: without treatment (T0) (control), hydrofluoric acid-etched (T1), hydrofluoric acid-etched associated with the airborne particle-abraded (T2); CoJet system (T3), Nd:YAG laser (T4). The data were performed the statistical analysis by ANOVA and Tukey's test (p < 0.001). RESULTS: The group control (T0) of the ceramics, the analysis showed the lowest roughness values; for the System Alumina In-Ceram, treatment with hydrofluoric acid (T1), associated with hydrofluoric acid and airborne particle-abraded (T2) and Nd:YAG laser (T4), had no statistically significant difference, whereas for the IPS Empress System II treatment with hydrofluoric acid (T1) and hydrofluoric acid associated with airborne particle-abraded (T2), had no statistically significant difference between the system and also CoJet (T3) and hydrofluoric acid associated with the airborne particle-abraded (T2). Photomicrographs of scanning electron microscopy showed different characteristics to the treatments for each ceramic system. CONCLUSION: The IPS Empress II had the appearance of favoring the retention when treated with hydrofluoric acid, as well as its association with the airborne particle-abraded. Uncertainty in Alumina, treatment with hydrofluoric acid associated with the airborne particle-abraded and CoJet system and provided a surface with irregularities. With respect to the laser further studies should be performed for parameters that are ideal for your application. CLINICAL RELEVANCE: The ceramic restorations are attractive due of their excellent esthetics and the ability to stay for long periods. However, the retention of ceramic requires further study.