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Objective To answer the question: "Does the peroxide gel application regimen (single application vs. renewal) influence the efficacy and the tooth sensitivity outcomes of in-office tooth bleaching?" Methods The search was done in Pubmed, Cochrane, LILACS, Scopus, Web of Science, and EMBASE in February 2021 (updated in July 2021). Randomized clinical trials (RCT) comparing the single application vs. the renewal protocols of HP were included. The meta-analyses were performed for the objective (ΔEab ), subjective (ΔSGU) color changes, and absolute risk of tooth sensitivity (TS). Heterogeneity was evaluated using Q test (I2 ). Cochrane Collaboration tool assessed the risk of bias (RoB). The GRADE evaluated the certainty of evidence. Results Five RCT studies remained. Two studies showed high RoB, and three presented some concerns. No significant differences were observed between the protocols in terms of the ΔEab , ΔSGU, and TS. ΔEab exhibited substantial heterogeneity (I2 = 87%), while ΔSGU (I2 = 60%) and the TS (I2 = 62%) presented a moderate one. The certainty of evidence was considered low or very low, depending on the variable response and the evaluation time. Conclusion The application regimen (single vs. renewal of HP) did not impact color change or the absolute risk of TS. Clinical significance The renewal of bleaching gel during the in-office appointment may not be necessary. However, there is at least a low certainty of evidence. Because of this, further randomized clinical trials with appropriate methodology on this topic are encouraged.

SUMMARY This study evaluated intrapulpal concentration and hydrogen peroxide (HP) penetration at the interface of teeth restored with bioactive composites, using conventional or bulk-fill composites. Cylindrical cavities were prepared on the buccal surface of bovine incisor crowns (n=20) and restored with: resin modified glass-ionomer (RMGI, Riva Light Cure, SDI), non-bioactive bulk-fill composite (FB, Filtek Bulk, 3M Oral Care), non-bioactive conventional composite (FZ, Filtek Z350, 3M Oral Care), bioactive bulk-fill composite (AC, Activa BioActive, Pulpedent), and bioactive conventional composite (BII, Beautifil II, Shofu). After 5,000 thermal cycles, restorations (n=10) were exposed to high (35% HP [4 applications of 8 min/session-4 sessions]) or low (9.5% HP [30 min/day-14 days]) concentration bleaching protocols. After the last bleaching application, the HP intrapulpal concentration was determined. Additional teeth were restored, pigmented with rhodamine B solution, and HP penetration around the interface was observed under laser scanning confocal fluorescence microscopy (LSCFM, n=3). The presence of gaps at the interface was observed on replicas of the cross-sectioned samples under scanning electron microscopy (SEM, n=5). Data were submitted to one-way (gap analysis) and twoway analysis of variance (ANOVA; HP intrapulpal concentration) and Tukey test (α=0.05). The LSCFM images were qualitatively analyzed. The restored teeth submitted to 35% HP presented higher HP intrapulpal concentration than teeth submitted to 9.5% HP (p0.05) when exposed to 9.5% HP. Lower HP intrapulpal concentration was observed for teeth restored with RMGI exposed to HP 35%, when compared with teeth restored with nonbioactive conventional (FZ; p=0.004) and bulk-fill composites (FB; p=0.01). No gap formation was observed at the outer enamel adhesive interface for all restorative materials. LSCFM images showed that 35% HP promoted greater degradation of rhodamine B at the enamel, except for RMGI. In this context, RMGI promoted lower HP intrapulpal concentration than non-bioactive conventional and bulk-fill composites.

Objectives The aim of this in vitro study was to incorporate two anti-caries agents, Apigenin and tt-Farnesol, to resin composite and resin cement to reduce the virulence of Streptococcus mutans around dental restorations. Methods Apigenin (Api, 5 mM) and tt-Farnesol (Far, 5 mM) were added alone, together, and combined with fluoride (F). Biofilm of S. mutans was grown on composite discs, and the dry-weight, bacterial viability, and the polysaccharides (alkali-soluble, intracellular and water-soluble) were quantified. CLSM images of the S. mutans biofilm were obtained after three years of water-storage. The effect of the additions on the physicochemical properties and the composite colorimetric parameters were also analyzed. Results The additions did not affect bacterial viability. Api alone and combined with Far or combined with Far and F decreased the bacterial dry-weight, alkali-soluble and intracellular polysaccharides. After three years, the composites containing the additions presented a greater EPS matrix on the top of biofilm. Statistical difference was obtained for the degree of conversion; however, the maximum polymerization rate and curing kinetics were unaffected by the additions. No difference was observed for the water-soluble polysaccharides, flexural strength, and elastic modulus. Api increased the yellowness of the composites. Significance Api, alone and combined, reduced the expression of virulence of S. mutans without jeopardizing the physicochemical properties of the composites.

To evaluate the microtensile dentin bond strength (BS) and dentin-adhesive morphology of three self-etching bonding systems and three universal adhesives applied in self-etching mode. Four single-s...

This in vitro study aimed to analyze the fracture strength and failure pattern of flared bovine roots restored with different intraradicular fiber posts and core materials, without a ferrule. To conduct this study fifty bovine incisor roots were treated endodontically, and divided into five groups (n=10), according to the following fiber post techniques and core materials: prefabricated fiberglass post and full-body bulk-fill resin composite (PF-BF); prefabricated fiberglass post and dual function resin cement (PF-RC); direct anatomic post and full-body bulk-fill resin composite (AP-BF); CAD-CAM integrated fiberglass post-and-core (CAD-PC); and adjustable fiberglass post and full-body bulk-fill resin composite (AD-BF). Intraradicular fiber posts were cemented with dual functional resin cement (Allcem Core, FGM), restored with CAD-CAM composite crowns (Brava, FGM), and subjected to loading. The data were analyzed by generalized linear models (p

Objectives: Etching approaches [37% phosphoric acid, self-etching, 10–3 solution (3% ferric chloride dissolved in 10% citric acid), or 1.4% nitric acid] were evaluated regarding enamel shear bond strength (24 h), dentin microtensile bond strength (24 h and 2 years), failure mode, enzymatic activity of the hybrid layer, and nanoleakage (24 h and 2 years) of Prime&Bond Universal (PBU, Dentsply-Sirona) and Gluma Bond Universal (GBU, Kulzer). Methods: Adhesives were applied on blot-dried (wet-bonding, positive control) or air-dried (remaining groups) dentin after acid-etching (15 s) or in self-etch mode. Enamel and dentin bond strength tests used 160 human teeth (n = 10). Failure mode of tested samples and nanoleakage within the dentin-adhesive interface (n = 5) were analyzed by scanning electron microscopy. Dentin enzymatic activity was investigated by in situ zymography (n = 3). Results: Enamel bond strengths did not differ statistically among groups. Wet-bonding with 37% phosphoric acid showed similar dentin bond strength compared to 10–3 solution or 1.4% nitric acid at 24 h for both adhesives. None of the etchants inhibited enzymatic activity, and all groups showed dentin bond strength reduction after 2-year storage. GBU showed higher nanoleakage. Experimental etchants did not affect enamel bond strength. Dentin bond strength was not stable after 2 years, despite promising 24-hour results. Significance: This study suggests multiple etching approaches to optimize and achieve stable dentin bonding, while also offering in-depth information about the performance of recently released universal adhesive systems.

This clinical report elucidates both uses of direct and indirect restoration techniques, in which a failure of the direct resin restoration after one year by tooth discoloration relapse was detected, and a ceramic veneer restoration was the final elected treatment. A poor marginal adaptation and mismatching color of a class IV resin composite restoration was observed, which was placed due to a traumatic dental injury, in which part of the enamel and dentin was lost but without tooth vitality impairment. Tooth bleaching was performed combining home and in-office bleaching techniques, followed by restoration replacement with resin composite in order to improve the dental esthetic. After one year of follow up, it was observed that the restored tooth was darker and the resin shade mismatch the tooth color, showing an evident restoration margin. In attempt to achieve a long lasting treatment, substitution of the direct composite by an indirect restoration was selected, using a unit ceramic veneer restoration, and followed up for four years. Conservative approaches should be the choice treatment in restorative dentistry, however the re-incidence of discolored tooth or the restoration material degradation must be taken into consideration before indicating a direct or indirect restoration.

SUMMARY Objectives: This study evaluated the effect of toothbrushing with a dentifrice on gloss, roughness profile, surface roughness, and wear of conventional and bulk-fill resin-based composites. Methods and Materials: Gloss and surface roughness of resin-based composites (RBCs; Admira Fusion X-tra, Aura Bulk Fill, Filtek Bulk Fill Flowable, Filtek Bulk Fill Posterior Restorative, Filtek Supreme Ultra, Herculite Ultra, Mosaic Enamel, SDR flow+, Sonic Fill 2, Tetric EvoFlow Bulk Fill and Tetric EvoCeram Bulk Fill) were analyzed before and after brushing; the roughness profile and wear were also determined after toothbrushing. Representative three-dimensional images of the surface loss and images comparing the unbrushed and brushed surfaces were also compared. Analysis of variance and Tukey post hoc tests were applied (α=0.05) to the gloss, surface roughness, roughness profile, and surface loss data. Pearson's correlation test was used to determine the correlation between gloss and surface roughness, surface loss and percentage of gloss decrease after brushing, and surface loss and surface roughness after brushing. Results: For all RBCs tested after 20,000 brushing cycles, the gloss was reduced and the surface roughness increased (p Conclusions: Toothbrushing with a dentifrice reduced the gloss, increased the surface roughness, and caused loss at the surface of all the RBCs tested. Considering all the properties tested, Mosaic Enamel exhibited excellent gloss retention and a low roughness profile and wear, while Admira Fusion X-tra exhibited the greatest decrease in gloss, the highest roughness profile, and the most wear.

CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico This study measured and compared exitance irradiance and power of 4 commercial dental light-curing units (LCU) (Elipar S10, Elipar DeepCure-S, Corded VALO and Bluephase Style) using different types of radiometers. The devices used to analyze the LCU were classified as either handheld analog (Henry Schein, Spring, Demetron 100A, Demetron 100B and Demetron 200), handheld digital (Bluephase 1, Bluephase II, Coltolux, CureRite and Hilux), or laboratory instruments (Thermopile and Integrating Sphere). The laboratory instruments and the Bluephase II radiometer were also used to measure the LCU’s power (mW). The LCU’s were activated for 20 s (n=5). Data were analyzed using Kruskal-Wallis and Student-Newman-Keuls multiple comparison test (a=0.05). Among the LCU, the laboratory instruments presented different irradiance values, except for Corded VALO. The Coltolux and Hilux radiometers measured greater irradiance values compared to the laboratory instruments for the four LCUs tested. Within a given LCU, handheld analog units measured lower irradiance values, compared to handheld digital and laboratory instruments, except using the Spring radiometer for the Elipar S10 LCU. None of the handheld radiometers were able to measure similar irradiance values compared to laboratory instruments, except for Elipar S10 when comparing Bluephase 1 and Thermopile. Regarding power measurement, Bluephase II always presented the lowest values compared to the laboratory instruments. These findings suggest that the handheld radiometers utilized by practitioners (analog or digital) exhibit a wide range of irradiance values and may show lower outcomes compared to laboratory based instruments Esse estudo mensurou e comparou a irradiância e a energia de quatro fotopolimerizadores comerciais (Elipar S10, Elipar DeepCure-S, Corded VALO e Bluephase Style) utilizando diferentes tipos de radiômetros. Os dispositivos utilizados para analisar os fotopolimerizadores foram classificados em portáteis analógicos (Henry Schein, Spring, Demetron 100A, Demetron 100B e Demetron 200), portáteis digitais (Bluephase 1, Bluephase II, Coltolux, CureRite e Hilux), ou instrumentos laboratoriais (Thermopile e Integrating Sphere). Os instrumentos laboratoriais e o radiômetro Bluephase II também foram utilizados para medir a energia dos fotopolimerizadores (mW). Os fotopolimerizadores foram ativados por 20 s (n=5). Os dados foram analisados utilizando Kruskal-Wallis e teste de Student-Newman-Keuls (a=0,05). Dentre os fotopolimerizadores, os instrumentos laboratoriais apresentaram diferentes valores de irradiância, exceto para o Corded VALO. O Coltolux e o Hilux mensuraram uma irradiância maior comparado aos instrumentos de laboratório para os quatro fotopolimerizadores testados. Para o mesmo fotopolimerizador, os radiômetros analógicos portáteis mensuraram menores valores de irradiância quando comparados aos digitais portáteis ou aos instrumentos laboratoriais, exceto quando utilizado o Spring para o Elipar S10. Nenhuma diferença foi observada entre os instrumentos laboratoriais na irradiância do Corded VALO. Para a medição da energia, nenhuma diferença foi observada usando Thermopile e a Integrating Sphere para o Corded VALO. Para os outros fotopolimerizadores, cada instrumento indicou uma energia diferente. Esses achados sugerem que radiômetros portáteis utilizados pelos cirurgiões-dentistas (analógico ou digital) exibem uma ampla gama de valores de irradiância e podem mostrar medidas inferiores comparados aos instrumentos de laboratório

Purpose The aim of this study was to evaluate the influence of indirect restorative material type and thickness on the transmission of different wavelengths from a broad-banded dental curing light. Methods Four dental indirect restorative materials for computer-aided design and computer-aided manufacturing (CAD/CAM) were evaluated: [RC] resin/ceramic hybrid material (Lava Ultimate), [FC] feldspathic ceramic (VitaBlocs), and two zirconia-based ceramics ([ZK] Katana; and [ZL] Lava). Total loss of irradiance (TL) was measured for blue (WB, 425–490 nm) and violet (WV, 350–425 nm) wavelengths. Specimens of 15 × 15 mm with varying thicknesses (0.5, 1.0, 1.5, and 2.0 mm) were fabricated (n = 5). A plasma-arc dental light-curing unit was used (Arc Light-II). To assess TL as a function of wavelength, a software (Spectra Suite v5.1) connected to a spectroradiometer (USB2000) and an integrating sphere (CTSM-LSM-60-SF) was used. Data was subjected to statistical analysis (two-way ANOVA and post-hoc Tukey test, α = 0.05). Results A 0.5 mm interposition resulted in TL from 50.5 to 67.2%, depending on material. Increased thickness resulted in higher TL for all materials. FC showed less TL compared to ZK. In general, WV showed higher TL than did WB, and WV/WB proportion decreased with increasing thickness. Conclusions Indirect materials significantly reduced TL, and this effect is greater with increasing thickness. WV showed lower penetration compared to WB.

This literature review describes the history, and discusses important aspects regarding bonding mechanisms, clinical performance, and current status of different types of dental adhesives. The development of dental bonding has remarkably changed concepts and procedures related to Restorative Dentistry. Buonocore’s report on enamel acid-etching, followed by the description of the hybrid layer by Nakabayashi and his co-workers, and the use of the total-etch protocol were some of the scientific breakthroughs responsible for changing paradigms in dental practice. Also, the synthesis of functional monomers that can chemically bond to dental hard tissues has helped increase clinicians trust on Adhesive Dentistry. According to the mechanism of action and mode of use, past and present (available in the market) dental adhesives can be divided in generations. Currently, user-friendly, simplified products and restorative techniques have become popular among clinicians, who require products that do not just bond to the tooth, but also present antibacterial, remineralizing and/or enzymatic-inhibitory effects that can increase the longevity of adhesive procedures. Therefore, due to the great range of available bonding agents, clinicians must understand how these products work, and how their composition and mode of use influence the clinical outcomes of adhesive procedures, in order to decide what is the best adhesive system for each clinical application.

This in vitro study evaluated the effect of the beam homogeneity of a multiple-peak light-curing unit on the surface microhardness and the effect of toothbrushing wear on the microhardness, surface roughness, roughness profile, volume loss, and gloss retention of incremental and bulk-fill resin-based composites (RBCs). A LED light-curing unit (VALO) with four LEDs at the tip end (405, 445, 465A, and 465B nm emission peak) was used according to each manufacturer-recommended time to obtain disks (n=10) of six RBCs: Estelite Sigma Quick, Charisma Classic, Tetric EvoCeram Bulk Fill, Filtek Z250, Filtek Supreme Ultra, and Filtek Bulk Fill. Microhardness values were obtained according to each LED positioning of the light-curing unit on the top surface of the RBCs and were analyzed before and after toothbrushing regarding microhardness, surface roughness, roughness profile, volume loss, and gloss retention. Microhardness was considered homogeneous on the top surface regardless of the type of RBC or wavelength tested (p>0.05). Overall, toothbrushing did not reduce the microhardness of the RBCs but influenced the gloss values for most RBCs (p0.05). In conclusion, different wavelengths of the LED did not affect the top surface microhardness, regardless of the RBCs tested; and bulk-fill composites presented similar surface changes (microhardness, surface roughness, roughness profile, volume loss, and gloss retention) when compared to conventional composites after toothbrushing. Resumo Este estudo in vitro avaliou a homogeneidade do feixe de um fotopolimerizador de múltiplos picos na microdureza superficial e o efeito da escovação na microdureza, rugosidade superficial, perfil de rugosidade, perda de volume e retenção do brilho de compósitos a base de resina (RBCs) incrementais ou bulk-fill. Um fotopolimerizador LED (VALO) com quatro LEDs na ponteira (405, 445, 465A e 465B nm de pico de emissão) foi usado de acordo com o tempo recomendado por cada fabricante para obtenção de discos (n=10) de seis RBCs: Estelite Sigma Quick, Charisma Classic, Tetric EvoCeram Bulk Fill, Filtek Z250, Filtek Supreme Ultra e Filtek Bulk Fill. Os valores de microdureza foram obtidos seguindo o posicionamento de cada LED na superfície superior das amostras e foram analisados antes e após a escovação quanto a microdureza, rugosidade superficial, perfil de rugosidade, perda de volume e retenção do brilho. A microdureza foi considerada homogênea no topo da superfície, independentemente do tipo de RBCs ou comprimento de onda testados (p>0.05). No geral, a escovação não reduziu a microdureza das RBCs, mas influenciou o brilho para a maioria das RBCs (p0.05). Em conclusão, os diferentes comprimentos de onda do LED não alteraram a microdureza do topo da superfície, independentemente das RBCs testadas; e as resinas bulk-fill apresentaram alterações superficiais similares (microdureza, rugosidade superficial, perfil de rugosidade, perda de volume e manutenção do brilho) quando comparadas às resinas convencionais após a escovação.

Objectives To evaluate the incorporation of doxycycline (DOX) into a commercial dental adhesive regarding physicochemical properties, microtensile bond strength (μTBS), nanoleakage (NL), nanohardness (NH) and Young's modulus (YM), metalloproteinases (MMP) inhibition, and antibiofilm activity. Methods DOX was incorporated into the adhesive at 0.05, 0.1, 0.5, and 1 wt%. Restored teeth were evaluated for μTBS, NL, NH, and YM after 24 -hs and 1-year of water storage. Biofilms of Streptococcus mutans were grown on top of these adhesives and determined for bacterial viability and amount of biomass. The inhibitory effect on MMP was analyzed by in situ zymography under confocal microscopy. Results Adhesives with 0.5 and 1 wt% of DOX presented reduced pH and degree of conversion. The incorporation of DOX did not affect μTBS and hybrid layer YM. The control group (no DOX) had a decrease in μTBS and the densest silver nitrate areas after 1-year storage. Hybrid layer NH values increased with 0.1 wt% DOX compared to control and 1 wt% DOX groups, at 24 -hs. After 1-year storage, NH of 1 wt% DOX adhesive decreased compared to the control group. The 0.5 and 1 wt% concentrations of DOX decreased the bacterial viability and the biofilm biomass. Confocal images suggest an increased MMP inhibition proportional to the percentage of DOX. Conclusion At any concentration, DOX-doped dental adhesives were able to inhibit MMP activity, diminish nanoleakage, and maintain the resin-dentin bond-strength after 1 year of artificial aging. Clinical significance Doxycycline-doped dental adhesive inhibited metalloproteinases activity and preserved interface bond strength. This formulation has a potential to improve adhesive restorations clinical longevity.

Objective To evaluate the effects of human saliva decontamination protocols on bond strength of resin cement to zirconia (Y-PSZ), wettability, and microbial decontamination. Materials and methods Zirconia plates were sandblasted and divided into (a) not contaminated, (b) contaminated with human saliva and: (c) not cleaned, (d) cleaned with air-water spray, (e) cleaned with 70% ethanol, (f) cleaned with Ivoclean, or (g) cleaned with nonthermal atmospheric plasma (NTAP). The wettability and microbial decontamination of the surfaces were determined after saliva contamination or cleaning. Monobond Plus (Ivoclar Vivadent) was applied after cleaning, followed by Variolink LC (Ivoclar Vivadent). The samples were stored 1 week before shear bond strength (SBS) testing, and data (SBS and wettability) were analyzed by one-way analysis of variance and Tukey test (α = .05). Results Saliva contamination reduced SBS to zirconia compared to not contaminated. Both Ivoclean and NTAP produced higher SBS compared to not cleaned and were not significantly different from the not contaminated. Ivoclean produced the highest contact angle, and NTAP the lowest. With the exception of using just water-spray, all cleaning protocols decontaminated the specimens. Conclusions Both Ivoclean and NTAP overcame the effects of saliva contamination, producing an SBS to zirconia comparable to the positive control. Clinical significance Dental ceramics should be cleaned prior to resin cementation to eliminate the effects of human saliva contamination, and Ivoclean and NTAP are considered suitable materials for this purpose.

This article reports a comprehensive restorative treatment using bulk-fill composites and discusses their properties and clinical performance. A 20-year-old man sought dental treatment due to the dark shade of his smile and multiple old amalgam fillings. Based on clinical and radiographic findings, and the patient's demand for tooth-colored fillings, treatment comprised enamel microabrasion and in-office dental bleaching, followed by the replacement of amalgam fillings by bulk-fill composites. Bulk-fill composites exhibit modifications in the filler size and shape or in the chemistry of monomers that allow them to be applied in thicker layers (4 to 5 mm), creating opportunities for simpler, faster, and more-efficient clinical procedures, as seen in the present report.

SUMMARYObjectives: This study evaluated the light output from six light-emitting diode dental curing lights after 25 consecutive light exposures without recharging the battery, tip accessibility in the posterior region, and light beam spread from light-curing units.Methods: Irradiance, spectral peak, and radiant exposure were measured with the battery fully charged (Bluephase Style, ESPE Cordless, Elipar S10, Demi Ultra, Valo Cordless, and Radii-Cal) and monitored for 25 light exposures (each lasting 10 seconds). The tip diameter was measured to identify the beam size and the ability of the six light-curing units to irradiate all areas of the lower second molar in the standard output setting.Results: Four curing lights delivered a single peak wavelength from 454 to 462 nm, and two (Bluephase Style and Valo Cordless) delivered multiple emission peaks (at 410 and 458 nm and 400, 450, and 460 nm, respectively). The irradiance and radiant exposure always decreased after 25 exposures by 2% to 8%, depending on the light unit; however, only ESPE Cordless, Valo Cordless, and Radii-Cal presented a statistical difference between the first and the last exposure. The tip diameter ranged from 6.77 mm to 9.40 mm. The Radii-Cal delivered the lowest radiant exposure and irradiance. This light was also unable to access all the teeth with the tip parallel to the occlusal surface of the tooth.Conclusion: Not all of the blue-emitting lights deliver the same emission spectra, and some curing lights delivered a lower irradiance (as much as 8% lower) after the 25th exposure.

Objectives The aim of this in vitro study was to analyze the effect of the incorporation of two anti-caries agents into dental adhesives on the reduction of the virulence of Streptococcus mutans and on the adhesion to dentin. Methods Apigenin (1 mM) and tt -Farnesol (5 mM) were added separately and in combination to a self-etch adhesive (CS3 — Clearfil S3 Bond Plus) and to an each-and-rinse adhesive (OPT — OptiBond S). Biofilm of S. mutans was grown on adhesive-coated hydroxyapatite disks for 115 h and bacterial viability, dry-weight, alkali soluble, water soluble, intracellular polysaccharides and protein were quantified. Bond strength and dentin-adhesive interface were performed to analyze the effects of the incorporation on the physical properties and to identify changes in hybrid layer morphology. Results Addition of Apigenin and Apigenin + tt -Farnesol to CS3, and Apigenin or tt -Farnesol to OPT reduced the dry-weight of S. mutans biofilm. Insoluble polysaccharide decreased with the addition of Apigenin to CS3 and tt -Farnesol to OPT. Intracellular polysaccharide decreased with addition of Apigenin and Apigenin + tt -Farnesol to CS3. No changes in dentin bond strength, resin–dentin interfacial morphology, total amount of protein and soluble polysaccharide were observed with the additions. Significance Biofilms that are less cariogenic around dental restorations could decrease secondary caries formation; in addition, the reduction of virulence of S. mutans without necessarily killing the microorganism is more unlikely to induce antimicrobial resistance.

Objectives This study evaluated three different sterilization/disinfection techniques for resin composites on bacterial growth and surface modification after decontamination. Methods Two resin composites were sterilized/disinfected with three different techniques: UV light, 1% chloramine T, and 70% ethanol. Four different times were used for each technique to determine the shortest time that the solution or UV light was effective. The influence of sterilization/disinfection technique on bacterial growth was evaluated by analyzing the metabolic activity, using the AlamarBlue™ assay, bacterial viability, and SEM images from biofilms of Streptococcus mutans. The surface change, after the process, was analyzed with ATR/FTIR and SEM images. The solutions used for decontamination (1% chloramine-T and 70% ethanol) were analyzed with 1H-NMR to identify any resin compounds leached during the process. Results One minute of decontamination was efficient for all three methods tested. Chloramine-T increased the surface porosity on resin composites, no changes were observed for UV light and 70% ethanol, however, 1H-NMR identified leached monomers only when 70% ethanol was used. No chemical change of the materials was found under ATR/FTIR analyses after the decontamination process. Chloramine-T, with no previous wash, increased the bacterial viability for both resin composites and increased the bacterial metabolism for the resin composite without fluoride. Conclusion UV light had no interference on the resin composites properties tested using 1 min of exposure compared to the other decontamination methods. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017.

This study evaluated the effects of alternative dentin conditioners on the bond strength, failure mode, and morphology of the bonding interface. Forty teeth were used for the bond strength test (n=8). The Adper Single Bond 2 (3M Oral Care) adhesive was applied on moist (control), and air-dried (experimental) etched dentin after treatment with 37% phosphoric acid (PA), 3% aluminum nitrate + 2% oxalic acid (NA), 6.8% ferric oxalate + 10% citric acid (FO), or 10% citric acid (CA). Data normality was analyzed by one-way ANOVA, followed by Tukey’s test (?=0.05). Failure modes were observed by scanning electron microscopy (SEM). The morphology of the bonding interface (n=2) was analyzed by confocal laser scanning microscopy (CLSM). Wet-bonding with PA led to higher bond strength than the other groups. Bond strengths of NA, FO, and CA did not differ among themselves (p > 0.05). Mixed failures were predominant in the control and CA groups, and adhesive failures were predominant for NA and FO. In the control group, a hybrid layer with long resin tags could be obtained. For NA and CA, the formation of poor-quality hybrid layers was evident, while no hybridization occurred in the FO group. Adhesive application on air-dried dentin etched with the tested conditioners led to poor hybrid layer formation and lower bond strengths compared to the wet-bonding with PA.

Objective The aim is to evaluate the effect of violet light (VL) and nonthermal atmospheric plasma (NTAP) combined with or without 35% hydrogen peroxide (HP) and 37% carbamide peroxide (CP). Methods Bovine crowns were divided into (n = 10) VL, VL/HP, VL/CP, NTAP, NTAP/HP, NTAP/CP, HP, CP, and C (control) groups. Color and whiteness change (CIELAB-Δ Eab, CIEDE2000-Δ E00 , whiteness index-ΔWID ), color parameters (ΔL, Δa, and Δb), and intrapulpal concentration (μL/mL) of HP were assessed by spectrophotometry. Scanning electron microscopy evaluated the morphology of enamel surface. Data were analyzed by two-way analysis of variance and Tukey (Δ Eab , ΔE00 , ΔWID , ΔL, and μL/mL) and Kruskal-Wallis and Mann-Whitney tests (Δ a and Δ b, α = 5%). Results VL increased ΔEab and ΔWID of CP (P .05) or cause alterations in enamel morphology. However, HP and CP promoted topographical changes. Conclusion VL and NTAP changed color to a lesser extent than bleaching gels. VL produced supplementary effectiveness only for CP (ΔEab and ΔWID ), without increasing HP diffusion or changing enamel morphology. Clinical significance Although violet LED light and nonthermal atmospheric plasma (NTAP) promoted in vitro perceptible bleaching without compromising enamel morphology, bleaching gels (hydrogen peroxide and carbamide peroxide) were more effective than VL or NTAP. VL or NTAP did not increase intrapulpal diffusion of peroxide.

Objectives This study evaluated the antimicrobial activity (by agar disk diffusion test, AD), viability of S. mutans biofilm (VB), and effect on resin-dentin interface (RDI) of six adhesive systems. Methods Three adhesives containing antibacterial components (Gluma 2Bond (G2B)/glutaraldehyde, Clearfil SE Protect (CSP)/MDPB and Peak Universal Bond (PUB)/chlorhexidine) and the corresponding adhesives with similar composition, but without antibacterial agents (Gluma Comfort Bond, GCB; Clearfil SE Bond, CSB and Peak LC Bond, PLB) were evaluated. AD was determined measuring the extent of halo formation following application of adhesives and control groups (light cured or not) to cultures of four strict anaerobic and four facultative bacteria. For VB, a UA159 biofilm was grown on adhesive-coated hydroxyapatite discs for five days, collected and processed to count the number of viable cells. For RDI analysis, adhesives were applied according to manufacturers' recommendations and teeth were restored with resin composite, sectioned to obtain bonded slices and visualized by SEM. Results An inhibition halo was observed for G2B (strict anaerobic/light cured and not light cured), CSP (strict anaerobic and facultative/light cured and not light cured) and PUB (strict anaerobic and facultative/not light cured). PUB when light cured produced an inhibition halo on L. casei and S. mutans only. G2B and CSP significantly reduced the viability of S. mutans . Adhesives containing antimicrobial compounds had no detectable effect on RDI. Conclusion The MDPB-containing bonding agent showed better results of inhibition for all oral pathogens tested and a decrease of viability of Streptococcus mutans biofilm, among the adhesives tested.

Este estudo avaliou o efeito da escovação de dentária no perfil de rugosidade (RP), rugosidade superficial (RS) e microdureza (MI) de compósitos. A unidade fotopolimerizadora Valo (Ultradent) foi utilizada para fotoativar seis compósitos: Z350XT (3M ESPE), Z250 (3M ESPE), Charisma (Kulzer), Filtek Bulk Fill (3M ESPE), Tetric Evoceram (Ivoclar Vivadent), e Estelite Asteria (Tokuyama). Os discos de compósitos foram confeccionados (n = 10) e submetidos à escovação (30.000 ciclos). As amostras foram analisadas em relação a RP, e RS por microscopia confocal. MI foi obtida antes e depois de escovar. A unidade fotoativadora foi colocada na mesma posição a fim de avaliar MI em dois conjuntos de medições que correspondem à localização do LED na superfície, composta: luz violeta (405 nm) e luz azul (465 nm). Os dados foram analisados por teste de T-pareado, ANOVA de dois e três fatores e teste de Tukey (α = 0.05). A escovação não alterou as propriedades da superfície de qualquer um dos compósitos, exceto para Charisma. Z350 quando fotoativado com luz violeta levou a uma redução de MI após a escovação.

Os adesivos odontológicos unem restauração dentária de resina composta à estrutura dental. Eles são São misturas de monômeros resinosos, solventes orgânicos, iniciadores, inibidores e, às vezes, partículas de carga. As principais indicações clínicas estão relacionadas à adesão das restaurações diretas de resina composta ao esmalte ou à dentina, para cimentar retentores intrarradiculares e/ou peças protéticas de cerâmica pura, compósito ou até mesmo metal, para selar margens de restaurações e para o tratamento de sensibilidade dentinária nos casos de exposição radicular. o tratamento do esmalte com ácido fosfórico aumentava a união da resina acrílica ao esmalte dental. tológicos: os convencionais, que são aplicados sobre esmalte e dentina previamente tratados com ácido fosfórico, e os autocondicionantes, capazes de desmineralizar e infiltrar os tecidos dentais simultaneamente, sem a necessidade de aplicação do ácido fosfórico. Os adesivos convencionais podem ser disponibilizados na forma de sistemas de três passos ou dois passos.Em ambos os casos, a primeira etapa da técnica adesiva consiste na aplicação de ácido fosfórico gel 35-37% em esmalte por 15 a 30 s e dentina por 15 s, com o objetivo de remover a smear layer6 , criar microporosidades no esmalte7 e desmineralizar a superfície dentinária, expondo a rede de fibrilas colágenas. Em seguida, o preparo deve ser lavado por 30 s para remoção dos resíduos do ácido fosfórico e de cristais solubilizados deixados na superfície9 . Então, para os sistemas de três passos, é feita a aplicação do primer, seguida por leve jato de ar para volatilizar o solvente. O primer contém monômeros hidrofílicos que deslocam a água presente na dentina7 e preparam o substrato para o passo subsequente, que é a aplicação da resina adesiva hidrófoba (bond). Por fim, o bond se difunde nos espaços entre as fibrilas colágenas e, após fotoativação pelo tempo recomendado pelo fabricante, o mesmo copolimeriza com o primer5 , criando uma camada ácido-resistente de dentina reforçada por resina – conhecida como camada híbrida, a qual é responsável pela união do material restaurador com a estrutura dental10 (Figura 2). Os adesivos convencionais de dois passos, por sua vez, unem primer e bond no mesmo frasco11, tornando necessária a aplicação de um único produto após o tratamento do dente com ácido fosfórico, seguida pela volatilização do solvente e fotoativação. Os agentes de união autocondicionantes dispensam a etapa clínica de tratamento da dentina com ácido fosfórico e podem ser disponibilizados como produtos de dois passos ou passo único. recomenda-se o condicionamento seletivo das margens de esmalte por 30 s, de modo a diminuir a descoloração, melhorar a adaptação das margens e aumentar a durabilidade das restaurações12. Para os adesivos autocondicionantes de dois passos, a primeira etapa clínica se baseia na aplicação ativa (esfregando contra a superfície) de um primer ácido que desmineralizará e infiltrará na dentina simultaneamente11, além de se ligar quimicamente ao cálcio da hidroxiapatita13. Leve jato de ar deve ser aplicado para volatilizar o solvente do primer e, em seguida, uma camada de bond é aplicada acompanhada por outro jato de ar, para deixá-la o mais uniforme possível. Após esses procedimentos, a superfície deve ser fotoativada pelo tempo recomendado pelo fabricante. Já no caso dos adesivos de passo único, basta aplicar o produto sobre a superfície em que será realizada a adesão, volatilizar o solvente e fotoativar o adesivo. Os adesivos autocondicionantes não removem a smear layer e desmineralizam a dentina muito superficialmente, criando uma camada híbrida delgada. Por isso, o uso destes sistemas em cavidades profundas de dentes vitais é recomendado. sistemas chamados de “universais' Estes adesivos podem ser utilizados com o condicionamento ácido prévio dos tecidos dentais ou como agentes autocondicionantes. O tratamento ácido do esmalte também é recomendado para os adesivos “universais” utilizados no modo autocondicionante agentes terapêuticos em sistemas adesivos, como antibacterianos, agentes remineralizantes e cross-linkers de colágeno, o que poderia ajudar no controle de cáries recorrentes19 e aumentar a longevidade da união dos materiais restauradores ao dente.

CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico The aim of this in vitro study was to synthesize three new methacrylate monomers based on the modification of saccharides structures (glucose-Gluc, sucrose-Sucr and chitosan-Chit) with glycidyl methacrylate, and to use them in the composition of dental adhesives. Three methacrylate saccharide monomers were synthesized and characterized by mid-IR, 1H and 13C NMR, antioxidant activity and cytotoxic effect. Monomers included: one monosaccharide – Gluc-MA; one disaccharide – Sucr-MA; and one polysaccharide – Chit-MA. Primers containing HEMA, methacrylate saccharide monomers at concentrations of 0 (control), 1, 2 or 4 wt%, 60 wt% ethanol aqueous solution (pH3.0) and initiator system were formulated. Primers were used in conjunction with a bond step and composite paste to restore caries-free third molars, and dentin bond strength (24 hours and 6 month of storage in water), and antimicrobial activity (Alamar Blue test) were tested. Degree of conversion (DC) and maximum rate of polymerization (Rpmax) of the primers themselves were also analyzed. The mid-IR, 1H and 13C spectrum confirmed the presence of vinyl group on the structure of saccharides. Chit-MA showed low antioxidant activity and did not present a cytotoxic effect. Gluc-MA and Sucr-MA possess antioxidant and cytotoxic activity, concentration dependent. In the presence of methacrylate saccharide monomers, the primers showed DC comparable to the control group, except Gluc-MA4%, Sucr-MA4% and Chit-MA1%, which showed a range of 64.6 from 58.5 %DC. Rpmax was not statistically different for all the groups (p = 0.01). The bond strength of Sucr-MA1% increased from 25.7 (±2.8) to 40.6 (±5.3) MPa after 6 months of storage. All the synthesized monomers showed some antimicrobial activity after polymerization. Gluc-MA and Chit-MA 4% and Sucr-MA 1, 2 and 4% led to decrease bacterial metabolism. Sucr-MA 1% showed better results regarding the decrease in bacterial metabolism and increasing the bond strength after 6 months of storage.

Objectives To evaluate the effect of experimental conditioners (10–3 solution − 10–3, 6.8% ferric oxalate - FOX, and 1.4% nitric acid - NI) on dentin elastic modulus, flexural strength, bond strength, failure mode, and adhesive interface morphology of two etch-and-rinse adhesives (XP Bond, Dentsply or One-Step, Bisco) applied on etched dry dentin. Methods Sound human third molars were used for the microtensile bond strength test (n = 8), performed at 24 h and after one year of water storage. Failure modes were evaluated by scanning electron microscopy. Dentin bonding interface was analyzed by confocal laser scanning microscopy (n = 3). Adhesive systems were applied on phosphoric acid-etched, wet (positive control) and dry (negative control) dentin, and on etched and dry dentin previously treated with 10–3 (15s), FOX (60s), or NI (15s). Bovine dentin bars (n = 15) were immersed into the conditioning solutions and subjected to a three-point bending test. Results XP Bond + 10–3 or NI resulted in lower bond strength than phosphoric acid. One-Step + 10–3 or NI resulted in bond strengths equivalent to the positive control. Experimental conditioners presented no bond strength reduction after one year, regardless of the bonding agent tested. One-Step resulted in more adhesive failures than XP Bond at 24 h, and mixed failures increased after storage. All experimental conditioners promoted hybridization and resin tags formation, except FOX. Dentin elastic modulus was not affected by the conditioners, whereas flexural strength was significantly reduced by FOX. Conclusions Adequate and stable dentin bonds were achieved when the bonding agents were applied on 10–3 or NI-treated dentin. None of the experimental conditioners reduced dentin elastic modulus, but dentin flexural strength was significantly reduced by FOX-conditioning.

CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico FAPESP - Fundação de Amparo à Pesquisa do Estado de São Paulo The effects of tooth brushing could affect the long-term esthetic outcome of composite restorations. This study evaluated the effect of two different emission spectrum light-curing units on the surface roughness, roughness profile, topography and microhardness of bulk-fill composites after in vitro toothbrushing. Valo (multiple-peak) and Demi Ultra (single-peak) curing lights were each used for 10s to polymerize three bulk-fill resin composites: Filtek Bulk Fill Posterior Restorative (FBF), Tetric EvoCeram Bulk Fill (TET) and Surefil SDR Flow (SDR). After 30,000 reciprocal strokes in a toothbrushing machine, the roughness profile, surface roughness, surface morphology, and microhardness were examined. Representative SEM images were also obtained. When light-cured with the Demi Ultra, SDR showed the most loss in volume compared to the other composites and higher volume loss compared to when was light-cured with Valo. The highest surface roughness and roughness profile values were found in SDR after toothbrushing, for both light-curing units tested. FBF always had the greatest microhardness values. Light-curing TET with Valo resulted in higher microhardness compared to when using the Demi Ultra. Confocal and SEM images show that toothbrushing resulted in smoother surfaces for FBF and TET. All composites exhibited surface volume loss after toothbrushing. The loss in volume of SDR depended on the light-curing unit used. Toothbrushing can alter the surface roughness and superficial aspect of some bulk-fill composites. The choice of light-curing unit did not affect the roughness profile, but, depending on the composite, it affected the microhardness

Objectives This study evaluated the dentine bond strength (BS) and the antibacterial activity (AA) of six adhesives against strict anaerobic and facultative bacteria. Methods Three adhesives containing antibacterial components (Gluma 2Bond (glutaraldehyde)/G2B, Clearfil SE Protect (MDPB)/CSP and Peak Universal Bond (PUB)/chlorhexidine) and the same adhesive versions without antibacterial agents (Gluma Comfort Bond/GCB, Clearfil SE Bond/CSB and Peak LC Bond/PLB) were tested. The AA of adhesives and control groups was evaluated by direct contact method against four strict anaerobic and four facultative bacteria. After incubation, according to the appropriate periods of time for each microorganism, the time to kill microorganisms was measured. For BS, the adhesives were applied according to manufacturers’ recommendations and teeth restored with composite. Teeth ( n = 10) were sectioned to obtain bonded beams specimens, which were tested after artificial saliva storage for one week and one year. BS data were analyzed using two-way ANOVA and Tukey test. Results Saliva storage for one year reduces the BS only for GCB. In general G2B and GCB required at least 24 h for killing microorganisms. PUB and PLB killed only strict anaerobic microorganisms after 24 h. For CSP the average time to eliminate the Streptococcus mutans and strict anaerobic oral pathogens was 30 min. CSB showed no AA against facultative bacteria, but had AA against some strict anaerobic microorganisms. Conclusions Storage time had no effect on the BS for most of the adhesives. The time required to kill bacteria depended on the type of adhesive and never was less than 10 min. Clinical significance Most of the adhesives showed stable bond strength after one year and the Clearfil SE Protect may be a good alternative in restorative procedures performed on dentine, considering its adequate bond strength and better antibacterial activity.

Purpose. To investigate the effect of light activation on the water sorption (WS) and solubility (SL) of resin cements after 24 h and 7 days. Methods. Disk-shaped specimens were prepared using five dual-polymerized cements (four self-adhesive [RelyX Unicem, MaxCem, SeT and G-Cem] and one conventional [Panavia F 2.0]) and divided according to the curing mode (direct light exposure or self-cure) and water immersion period (24 h or 7 days). Specimens were dry-stored and weighed daily until a constant mass was recorded (M1). Then, specimens were stored in water for either 24 h or 7 days and immediately weighed (M2). After desiccation, specimens were weighed again until a constant mass was achieved (M3). WS and SL were calculated and statistically analyzed by Kruskal-Wallis, Dunn and Mann-Whitney U tests (α=0.05%). Results. There was a significant increase in WS for all products after one-week immersion in water. The highest water uptake was observed for autopolymerized groups. Extended water immersion significantly affected the SL for most of autopolymerized cements. Significant differences between products were observed in both tests. Conclusions. The curing mode and the water immersion period may affect the mechanical stability of the resin cements, and these differences appear to be product-dependent.

This study evaluated the effects of humidity conditions and evaluation times on the dentin bond strength (DBS) of two self-adhesive resin cements (RC). The RC used were: RelyX Unicem (3M ESPE) and Clearfil SA Cement (Kuraray Med.). One hundred and twenty coronal portions of bovine incisors (n = 10) were used. Buccal surfaces were abraded in order to expose a flat dentinal surface (180-grit SiC) and to standardize the smear layer formation (600-grit SiC). The humidity conditions tested were: dry (air-dried for 10 s), slightly moist (water application with disposable applicator on dried dentin and water excess removed with absorbent paper), and moist (same application without water removal). The RC were used according to the manufacturers' recommendations and were applied to prepolymerized resin discs (2 mm thick; Sinfony, 3M ESPE), which were subsequently bonded to the dentin surfaces. After 24 h, half of the teeth were prepared for the microtensile bond strength test, while the other half were stored in water for 6 months and tested in tension (0.5 mm/min) until failure. A 3-way analysis of variance and the Tukey test were performed (preset alpha of 0.05). No RC showed any reduction of DBS after 6 months, and no significant difference was observed between them. The moist dentin increased the bond strength of Clearfil SA Cement for both periods of time. Humidity conditions can change the DBS; however, the study's results were product-dependent.

SUMMARY Purpose: To investigate the bond strength performance of multimode adhesives (MMAs) to indirect resin composite and lithium disilicate glass ceramic after 24 hours or one year of water storage. Methods and Materials: Thirty flat and polished plates of indirect resin composite (Epricord) and thirty lithium disilicate glass ceramic plates (IPS e.max Press) were prepared. Surfaces were pretreated using sandblasting (indirect resin composite) or hydrofluoric acid (glass-based ceramic). Specimens were bonded with one of two MMAs (Scotchbond Universal [SBU] or All-Bond Universal [ABU]) or ceramic primer and hydrophobic bonding (RelyX Ceramic Primer and Adper Scotchbond Multi-Purpose Bond) as a control (n=10). Resin cement cylinders (0.75 mm in diameter × 0.5 mm in height) were bonded to both substrate surfaces using the respective adhesives. After 24 hours or one year of water storage, bonding performance was measured by microshear bond strength (MSBS) testing. Results were analyzed using three-way ANOVA with Bonferroni post hoc tests (α=0.05). Results: For indirect resin composite, significantly higher MSBS values were found for ABU after 24 hours (ABU > SBU = control); however, no significant difference among the adhesives was observed after one year (p>0.05). For glass-based ceramic, significantly different bond strengths were observed among the adhesives after 24 hours (control = ABU > SBU) and one year (control > SBU = ABU; p Conclusions: Both MMAs tested can be considered effective alternatives for bonding to sandblasted indirect resin composite after aging, as they showed similar bond performance to that of the control group. However, separate bottles of silane bonding resin showed higher MSBS values and more durable bonding for etched glass–based ceramic.

Purpose: The aim of this study was to evaluate the resin–dentin morphology created by four dual-cured resin cements. Materials and Methods: Two self-adhesive resin cements (RelyX Unicem, 3 M ESPE and Clearfil SA Luting, Kuraray Med.) and two conventional resin cementing systems (RelyX ARC, 3 M ESPE and Clearfil Esthetic Cement, Kuraray Med.) were evaluated. Occlusal dentin surfaces of 32 extracted human third molars were flattened to expose coronal dentin. Teeth were assigned to 8 groups (n=4), according to resin cement products and microscope analysis (SEM: scanning electron microscope or CLSM: confocal laser scanning microscopy). For CLSM, two different fluorescent dyes, fluorescein isothiocyanate–dextran and rhodamine B, were incorporated into the adhesive system and resin cement, respectively. The resin cements were applied to indirect composite resin disks, which were cemented to dentin surface according to manufacturer's instructions. After 24 h, all restored teeth were vertically sectioned into 1-mm-thick slabs for SEM or CLSM analyses. Results: Scotchbond Multi-Purpose Plus/RelyX ARC cementing system formed a thin hybrid layer and resin tags penetration into the dentin tubules. Clearfil DC Bond/Clearfil Esthetic Cement showed only short resin tags. Neither hybrid layer nor resin tags were detected for self-adhesive resin cements. Conclusion: Representative SEM and CLSM images provided resin–dentin interfaces variability among resin cements studied.

Made available in DSpace on 2018-11-12T17:26:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-08-01. Added 1 bitstream(s) on 2018-11-12T17:34:21Z : No. of bitstreams: 1 S0103-64402015000400363.pdf: 137938 bytes, checksum: 7bb48977b3b3e779a14efdda957741db (MD5) Este estudo avaliou os efeitos do tipo de material restaurador indireto, da condição de ativação e do tempo no grau de conversão de um cimento resinoso de dupla ativação, utilizando espectroscopia de luz infravermelha. O cemento resinoso (RelyX Unicem 2, 3M ESPE) foi aplicado à superfície do diamante da unidade de reflectância atenuada e ativado segundo as seguintes condições: ativação química, exposição direta da luz e aplicação da luz através de dois materiais protéticos: resina nano-cerâmica (Lava Ultimate, 3M ESPE) ou cerâmica feldspática (Vita Blocks Mark II, Vita Zahnfabrik). Quatro espessuras de cada um desses materiais (0,5; 1,0; 1,5 e 2,0 mm) foram analisadas e a ativação realizada com luz LED. Os dados (n=5) foram analisados pela ANOVA três fatores, testes de Tukey e Dunnett (5%). Nenhuma diferença do grau de conversão foi observada entre os materiais. Todos os grupos mostraram maior grau de conversão após 10 min que após 5 min. Em ambos os tempos, o grupo ativado quimicamente teve menor grau de conversão que todos os grupos fotoativados. O grau de conversão foi reduzido somente quando foi utilizada a peça protética de 2 mm. Espessas peças protéticas podem reduzir o grau de conversão do cemento resinoso. A grau de conversão após 10 min é maior que após 5 min da cimentação. A ativação química produz menor grau de conversão que a fotoativação. This study evaluated the effects of indirect restorative materials, curing conditions and time on the degree of conversion (DC) of a dual-cured resin cement using infrared spectroscopy. The resin cement (RelyX Unicem 2, 3M ESPE) was applied to the diamond surface of a horizontal attenuated-total-reflectance unit and activated using one of following conditions: self-cure, direct light exposure, light exposure through indirect restorative materials (resin nano-ceramic: Lava Ultimate, 3M ESPE or feldspathic ceramic: Vita Blocks Mark II, Vita Zahnfabrik). Four thicknesses (0.5, 1.0, 1.5 or 2.0 mm) of each indirect material were analyzed, and the light-activation was performed using a blue LED light. Data (n=5) were analyzed by three-way ANOVA, Tukey's post hoc and Dunnett's tests (α=5%). No significant differences in DC were observed between indirect materials of similar thickness. All groups exhibited higher DC after 10 min than after 5 min. At both times points, the self-cure group exhibited significantly lower DC than all the light exposure groups. Only when the overlying indirect restoration had a thickness of 2 mm did DC decrease significantly. The presence of a thick, indirect restoration can decrease the DC of resin cement. DC after 10 min was higher than after 5 min. The self-cure mode yielded lower DC than the light-activating one. Universidade Estadual Paulista Piracicaba Dental School Department of Restorative Dentistry Georgia Regents University College of Dental Medicine Department of Oral Rehabilitation Universidade Estadual Paulista Piracicaba Dental School Department of Restorative Dentistry

The objective of this study was to analyze the dentin-resin cements interfacial ultramorphologies using two different methods: scanning (SEM) and transmission electron microscopy (TEM). Four commercial products were evaluated: two conventional cementing system (RelyX ARC/Adper™ Scotchbond™ Multi-Purpose Plus, 3M ESPE and Clearfil Esthetic Cement/DC Bond, Kuraray) and two self-adhesive resin cements (RelyX Unicem, 3M ESPE and Clearfil SA Cement, Kuraray). Prepolymerized resin disks (Sinfony, 3M ESPE) were cemented on oclusal dentin surfaces of 24 third human molars, simulating the indirect restorations. After 24 h, teeth were sectioned into 0.9-mm thick slabs and processed for microscopy analyses (SEM or TEM/ n = 3). Qualitative characterization of dentin-resin cement interface was performed. Hybrid layer formation with long and dense resin tags was observed only for RelyX ARC cementing system. Clearfil Esthetic Cement/DC Bond system revealed few and short resin tags formation, whereas no hybridization and resin tags were detected for self-adhesive resin cements. Some interfacial regions exhibited that the self-adhesive resin cements were not bonded to dentin, presenting bubbles or voids at the interfaces. In conclusion, TEM and SEM bonding interface analyses showed ultramorphological variations among resin cements, which are directly related to dental bonding strategies used for each resin cement tested.

Statement of problem The lack of long-term bond stability between resin cements and dentin may compromise the success of indirect restorations. Purpose The purpose of this study was to evaluate the effects of long-term storage in artificial saliva and mechanical load cycling on the microtensile bond strength of conventional and self-adhesive resin cements to dentin. Material and methods The occlusal dentin surfaces of 128 human molars were exposed and flattened. The teeth were assigned to 16 groups (n=8) according to resin cement and in vitro aging strategy. Two self-adhesive resin cements (RelyX Unicem and Clearfil SA Cement) and 2 conventional cementing systems (RelyX ARC and Clearfil Esthetic Cement) were used. Resin cements were applied to prepolymerized indirect resin disks, which were bonded to the dentin surfaces and light polymerized. The control groups were represented by immediate microtensile bond strength (24 hours) and aging methods were performed with mechanical load cycling or storage in artificial saliva (1 year and 2 years). Bonded beams were tested in tension until failure. Data (MPa) were analyzed by Proc Mixed for repeated measures and the Tukey-Kramer test (α=.05). Results The self-adhesive resin cements exhibited higher microtensile bond strength than conventional cementing systems for all conditions studied. The microtensile bond strength of RelyX ARC and self-adhesive resin cements did not decrease after storage in artificial saliva and mechanical load cycling. The Clearfil Esthetic Cement showed the lowest microtensile bond strength and a significant reduction after 2 years of storage in artificial saliva. Conclusions The storage times and mechanical load cycling did not affect the microtensile bond strength of self-adhesives and RelyX ARC resin cements. The highest microtensile bond strength was obtained for self-adhesive resin cements, with no significant difference between them.