Abstract The efficacy of whitening toothpastes is questionable and controversial. Clinicians, patients and researchers have expressed concern with whitening toothpastes due to the risk of wearing the dental structure and the potential for disappointment if the advertised cosmetic results are not achieved. Objective: This study compared the whitening performance of toothpastes with different whitening technologies after initial and continued use. Material and Methods: Ninety bovine incisors were stained using a concentrated solution of black tea. They were randomly distributed into 6 groups, according to the toothpaste whitening technology: activated charcoal (B&W), blue covarine (WAD), hydrogen peroxide (LWA), microbeads (Oral B 3D White Perfection – 3DW) and optimized abrasives (XW4D). They were compared to a traditional toothpaste without a whitening agent (TA – control). Specimens underwent a brushing machine with controlled pressure, time and temperature. A calibrated examiner measured the color using a VITA-Classical scale before the first brushing cycle (T0), after the first brushing cycle (TI), and after a brushing cycle that simulates continuous use (TCU). Whitening performance was evaluated by the difference of shades (ΔSGU) between T0–TI and T0–TCU timepoints, using the Kruskal-Wallis and Dunn's non-parametric test. The Wilcoxon test was used to evaluate the cumulative effect (α=0.05). Results: Statistically significant differences were observed between toothpastes in both TI and TCU (p<0.05). The time of use also had a significant effect (p<0.05). Conclusion: Only WAD and 3DW showed whitening performance after the first use (TI). The greatest whitening performance after continuous use was obtained by WAD, followed by LWA and 3DW. The use of conventional toothpaste (TA) promotes no tooth whitening. Clinical relevance: Microbead abrasives (3DW) and blue covarine (WAD) were the active technology tested that presented the best global tooth whitening performance.

RESUMO Objetivo: Comparar diferentes resinas compostas em relação á estabilidade de cor após exposição prolongada em solução de café. Métodos: Sessenta e quatro discos cilíndricos (10mm x 2mm) foram confeccionados a partir de 8 diferentes marcas comerciais de compósitos (n= 8 por grupo); os espécimes foram imersos em saliva artificial, e posteriormente em café, sendo por conseguinte feita a avaliação da variação cromática (ΔE), utilizando espectrofotômetro Vita Easyshade Advanced (VITA Zahnfabrik, Bad Sackingen, Germany). O padrão de cada espécime foi medido examinando as coordenadas L*, a* e b* do sistema CIELab. Resultados: A resina composta Grandio SO apresentou a menor média de variação cromática (ΔE= 7,77) após a imersão em solução de café. Semelhantemente, a variação cromática das resinas compostas Durafill VS, Grandio e Z350 XT (ΔE=8,58; ΔE=9,52; ΔE=10.39) que não apresentaram diferença estatística. Todavia, as demais resinas compostas avaliadas apresentaram valores estatisticamente maiores de ΔE em relação a resina Grandio SO, sendo que a resina Enamel HRi (ΔE= 20,56) apresentou a maior variação cromática registrada. Conclusão: As resinas da categoria bulk fill e as resinas híbridas produzidas pelo mesmo fabricante (Micerium, Avegno, Itália) tiveram alterações cromáticas superiores às demais resinas testadas sendo que a resina GrandioSO (Voco, Cuxaven, Alemanha) foi a que apresentou menor alteração de ∆E.

ABSTRACT Objective: This study compared the color stability of different dental composite resins after prolonged exposure to a coffee solution. Methods: Sixty-four cylindrical discs (10 mm diameter x 2 mm thickness) were prepared using 8 different dental composite resins (n=8, per group). The specimens were first immersed in artificial saliva for 24 h followed by immersion in a coffee solution for 14 days. The assessment of chromatic variation (ΔE) was performed with the aid of a Vita Easyshade Advanced spectrophotometer (VITA Zahnfabrik, Bad Sackingen, Germany). The color of each specimen was calculated based on the L*, a* and b* coordinates of the CIELab system. Results: Grandio SO had the lowest average chromatic variation (ΔE=7.77) after immersion in coffee solution. Durafill VS, Grandio and Z350 XT (ΔE=8.58; ΔE=9.52; ΔE=10.39, respectively) showed similar chromatic variation, with no statistical difference in relation to Grandio SO. However, the other dental composite resins evaluated showed statistically higher values of ΔE compared to Grandio SO, and Enamel HRi (ΔE=20.56) demonstrated the highest chromatic variation. Conclusion: The Bulk Fill and hybrid composite resins from the same manufacturer (Micerium, Avegno, Italy) showed greater chromatic variation than the other composite resins tested. Grandio SO (Voco, Cuxaven, Germany) had the lowest ΔE variation.

ABSTRACT: The purpose of this study was to investigate the accuracy and interobserver reliability of examiners with different levels of clinical experience, when diagnosing radiographic proximal caries lesions. Bitewing radiographs were selected from a patient attending Operative Dentistry Clinic, Universidad de Chile. Radiographic examination was performed by three different groups: A: third year dentistry students, B: fourth year dentistry students, and C: dentist recently graduated. Thirty-two proximal surfaces were scored as: 0, sound; 1: enamel caries; and 2: dentinal caries. The data were analysed and accuracy and interexaminer reliability were calculated. Accuracy values for enamel caries were: A (0.54), B (0.55) and C (0.58), and dentinal caries were: A (0.55), B (0.61) and C (0.63). Interexaminer reliability denoted marginal agreement for all groups, A (0.249), B (0.213) and C (0.282) for enamel caries and A (0.058), B (0.102), and C (0.344) for dentinal caries. The results of this study indicate that the accuracy and interexaminer reliability of bitewing radiographic examination were influenced by the clinical experience when detecting radiographic proximal caries, however low values of accuracy and interexaminer reliability were noted, reinforcing the necessity of improving education and training in radiographic caries detection.

RESUMEN:El objetivo de este trabajo fue evaluar la precisión y concordancia entre examinadores con distinto nivel de experiencia clínica, al diagnosticar lesiones de caries proximales en radiografías. Un set de radiografías bitewing fue seleccionado de un paciente que acudió a la Clínica de Operatoria de la Facultad de Odontología, Universidad de Chile. El examen radiográfico fue realizado por tres grupos distintos: A: estudiantes de Odontología de tercer año, B: estudiantes de Odontología de cuarto año, y C: dentistas recientemente graduados. Treinta y dos superficies proximales fueron analizadas y evaluadas como: 0, sana; 1: lesión de caries de esmalte, 2: lesión de caries dentinaria. Los datos obtenidos fueron analizados y la precisión y concordancia entre examinadores fueron calculadas. Los valores de precisión en lesiones de esmalte fueron: A (0,54), B (0,55) y C (0,58), y para lesiones dentinarias fueron: A (0,55), B (0,61) y C (0,63). La concordancia entre examinadores denotó ser marginal para todos los grupos, A (0,249), B (0,213) y C (0,282) en lesiones de esmalte y A (0,058), B (0,102), y C (0,344) en lesiones dentinarias. Los resultados de este estudio indican que la precisión y la concordancia entre examinadores está influenciada por la experiencia clínica, sin embargo los valores encontrados fueron bajos, lo que refuerza la necesidad de mejorar la educación y entrenamiento en detección de lesiones de caries en radiografías

Abstract Objective To prepare nanocomposite cements based on the incorporation of bioactive glass nanoparticles (nBGs) into BiodentineTM (BD, Septodent, Saint-Maur-des-Fosses Cedex, France) and to assess their bioactive properties. Material and Methods nBGs were synthesised by the sol-gel method. BD nanocomposites (nBG/BD) were prepared with 1 and 2% nBGs by weight; unmodified BD and GC Fuji IX (GIC, GC Corporation, Tokyo, Japan) were used as references. The in vitro ability of the materials to induce apatite formation was assessed in SBF by X-ray diffraction (XRD), attenuated total reflectance with Fourier transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. BD and nBG/BD were also applied to dentine discs for seven days; the morphology and elemental composition of the dentine-cement interface were analysed using SEM-EDX. Results One and two percent nBG/BD composites accelerated apatite formation on the disc surface after short-term immersion in SBF. Apatite was detected on the nBG/BD nanocomposites after three days, compared with seven days for unmodified BD. No apatite formation was detected on the GIC surface. nBG/BD formed a wider interfacial area with dentine than BD, showing blockage of dentine tubules and Si incorporation, suggesting intratubular precipitation. Conclusions The incorporation of nBGs into BD improves its in vitro bioactivity, accelerating the formation of a crystalline apatite layer on its surface after immersion in SBF. Compared with unmodified BD, nBG/BD showed a wider interfacial area with greater Si incorporation and intratubular precipitation of deposits when immersed in SBF.

RESUMEN. Introducción: el objetivo del presente estudio consistió en implementar la técnica de qPCR en tiempo real para identificar y cuantificar la especie Streptococcus mutans en muestras de saliva y biopelícula dentaria. Métodos: se seleccionaron al azar 27 niños de 8 años de edad, de nivel socio-económico bajo del área norte de la región metropolitana de Santiago de Chile, que se citaron en ayunas y sin cepillado durante al menos 12 horas, para colectar saliva no estimulada y un pool de biopelícula dentaria supragingival de todas las caras mesio-vestibulares de dientes anteriores y posteriores. Se cuantificó la cantidad de S. mutans en las muestras mediante qPCR empleando partidores que amplifican un fragmento del gen gtfB de S. mutans. Resultados: la amplificación presentó 98% de eficiencia con delta de fluorescencia de 3,36 ciclos. La curva de fusión (melting) presentó un solo máximo a una misma temperatura para todas las muestras. Conclusión: la metodología permite la identificación y cuantificación específica del gen gtfB de S. mutans en muestras de saliva y biopelícula dentaria, de forma rápida y exacta, aportando a la determinación del riesgo cariogénico individual.

ABSTRACT Introduction: the objective of this study was to use real-time qPCR to identify and quantify the Streptococcus mutans species in samples of saliva and dental biofilm. Methods: 27 children were randomly chosen with the following criteria: 8 years of age, low socio-economic levels, residing in the northern metropolitan area of Santiago de Chile; they were asked to attend an appointment while fasting with no teeth brushing for at least 12 hours, in order to collect non-stimulated saliva and a pool of supragingival dental biofilm of all the mesio-vestibular sides of anterior and posterior teeth. The amount of S. mutans in the samples was quantified by qPCR using primers that amplify a fragment of the gtfB gene of S. mutans. Results: the amplification showed 98% efficiency with a fluorescence of 3.36 cycles. The melting curve presented a single maximum at the same temperature for all samples. Conclusion: the methodology allows the specific identification and quantification of gene gtfB of S. mutans in saliva and dental biofilm in a quick and reliable manner, contributing to the identification of individual cariogenic risk.

Abstract The objective of this study was to analyze the effect of bleaching toothpastes, both conventional and those containing the new whitening agent Blue Covarine, on teeth previously bleached by conventional techniques (in-office and at-home). Squared bovine enamel/dentin blocks (6.0 x 6.0 x 2.0 mm) were randomly distributed in 6 groups (n = 15), according to the technique used to bleach them (in-office: HP35%; at-home: PC10%) and the type of bleaching toothpaste (none: control; Blue Covarine containing: BC; and without Blue Covarine: NBC). Experimental groups denominated HP35%, HP35%BC and HP35%NBC received in-office tooth bleaching before toothbrushing, and groups PC10%, PC10%BC and PC10%NBC were subjected to at-home tooth bleaching prior to toothbrushing. After bleaching treatment, groups HP35%BC, PC10%BC, HP35%NBC and PC10%NBC underwent daily tooth brushing in a brushing machine for 3 minutes (150 strokes/min, with a load of 375 g). Tooth color alteration was measured by reflectance spectroscopy (Vita EasyShade, Vident, Brea, CA, USA) at: T0 (baseline) – after in-office or at-home bleaching treatment; T1 – immediately after tooth brushing; T2 - 7 days and T3 - 14 days after tooth brushing. Data was analyzed by repeated measures mixed ANOVA and the Bonferroni post hoc test, with a significance level of 5%. Statistically significant differences were found between different experimental groups, evaluation times and for the interaction between them (p < 0.001). Tooth brushing using either bleaching toothpaste (conventional or with Blue Covarine) showed no color alteration on teeth previously bleached by in-office and at-home tooth bleaching. The use of bleaching toothpastes on previously bleached teeth did not produce a color alteration.

ABSTRACT Objective The purpose of this in vitro study was to compare the efficacy of a bleaching toothpaste containing Blue Covarine vs. conventional tooth bleaching techniques using peroxides (both in-office and at-home). Material and Methods Samples were randomly distributed into five experimental groups (n=15): C - Control; BC – Bleaching toothpaste containing Blue Covarine; WBC – Bleaching toothpaste without Blue Covarine; HP35 - In-office bleaching using 35% hydrogen peroxide; and CP10 – At-home bleaching with 10% carbamide peroxide. The dental bleaching efficacy was determined by the color difference (ΔE), luminosity (ΔL), green-red axis (Δa), and blue-yellow axis (Δb). The CIELab coordinates were recorded with reflectance spectroscopy at different times: T0 - baseline, T1 – immediately after bleaching, T2 - 7 days, T3 - 14 days, and T4 - 21 days after the end of treatments. Data were analyzed by a repeated measures mixed ANOVA and post hoc Bonferroni test, with a significance level of 5%. Results No significant differences were found between the treatment groups C, BC, and WBC. The groups HP35 and CP10 showed significantly higher whitening efficacy than groups C, BC, and WBC. Conclusions There were no significant differences in the whitening efficacy between a Blue Covarine containing toothpaste, a standard whitening toothpaste, and a control. Neither of the whitening toothpastes tested were as effective as in-office or at-home bleaching treatments.

Loosening is the most common failure of fiber posts, mainly due to complex adhesion within the root canal. The main objective of this study was to determine if significant differences in adhesive resistance, using the push-out test, in the cementation of fiber posts with RelyX U-200® (U200) and Core Paste XP® (CPX) in different root regions. Material and methods A selection of 40 premolars were sectioned 15 mm from the apex, treated endodontically and then randomly divided in two groups of 20, using an Exacto translucent fiber post with U200 and CPX, respectively. After 24 hours, each sample was sectioned into cervical, middle and apical. The test push-out test was performed using a Tinius Olsen HK5-S machine to quantify the adhesive strength in Mega Pascals. The test Shapiro-Wilk, two-factor Anova and Tukey tests were used with a significance level of 95% Results There were no significant differences between the cements (P = .457) but if there was difference when comparing the type of cement and region. CPX showed a value significantly higher in the cervical third (P < .05), while U200 presented a value significantly higher in the apical third (P < .05). Conclusions There was no significant difference in the value of the adhesive strength in the comparison between U200 and CXP, however there was a higher value of CXP at cervical and U200 at apical level.

La causa de fracaso más común de los postes de fibra es su desalojo, principalmente debido a la compleja adhesión dentro del conducto radicular. El principal objetivo de este estudio fue determinar si existe diferencia significativa en la resistencia adhesiva mediante el test push-out en la cementación de postes de fibra con RelyX U-200® (U200) y Core Paste XP® (CPX) en diferentes regiones radiculares. Material y métodos Se seleccionaron 40 premolares, se seccionaron a 15 mm del ápice, fueron tratados endodóncicamente y fueron divididos aleatoriamente en 2 grupos de 20, a los cuales se les cementó un poste de fibra translúcido Exacto® con U200 y CPX. Después de 24 h cada muestra fue seccionada transversalmente a nivel cervical, medio y apical. Fueron sometidas al test de push-out mediante la máquina Tinius Olsen HK5-S para cuantificar la resistencia adhesiva en megapascales. Se utilizó el test Shapiro-Wilk, test de ANOVA de 2 factores y Tukey con un nivel de significación del 95%. Resultados No hubo diferencia significativa de ambos cementos (p = 0,457), pero sí hubo diferencia cuando se comparó el tipo de cemento y la región; CPX presentó valor significativamente mayor en el tercio cervical (p < 0,05), mientras que U200 presentó un valor significativamente mayor en el tercio apical (p < 0,05). Conclusiones No hubo diferencia significativa en el valor de adhesión cuando se comparó solo el factor cemento entre U200 y CXP, sin embargo hubo un mayor valor de CXP a nivel cervical y de U200 a nivel apical.

AIM:To determine indicators of prognosis for mechanical risks of amalgam and composite resin restorations in permanent teeth.METHODS: Thirty-nine adult patients with direct clinical, photographic, radiographic and model examinations. A total of 256 restorations were classified as "not satisfactory," with Bravo or Charlie values according to the modified Ryge /USPHS criteria. The total "n" was divided into Bravo and Charlie groups according to the value obtained in the "marginal adaptation" parameter. Each of the groups was sub-divided by the type of material (amalgam and composite resins) and the class: occlusal (O) and proximal (MOD).RESULTS: Comparing the Bravo and Charlie groups, the statistically significant indicators were: the mesiodistal dimension (p=0.037), the distal isthmus (p<0.05), the average of the isthmuses (p<0.05), the distal (p<0.05) cavity depth, and the average depth of the MOD (p<0.05) cavities. It was concluded that the type and the class of the restoration are not indicators for sampling.CONCLUSIONS: With regard to the design of the cavity preparation, the valid mechanical risk indicators include the mesiodistal dimension, the distal isthmus, the average of the isthmuses, the depth of the distal cavity and the average depth of the MOD cavities. A simple clinical assessment does not provide sufficient information to establish the indicators for mechanical failure risk of restorations.

AIM: To correlate the tray technique for isolation and counting of Streptococcus mutans over dental restoration with the toothpick technique. METHODS: Forty 18-50-year-old patients of both genders with high cariogenic risk were selected. Inclusion criteria were: occlusal restoration evaluated as alpha, according to the Ryge's criteria (examiner' Cohen-Kappa 0.8) and 2 years old maximum age. Each patient provided a saliva sample (control group S) and two samples of dental biofilm from amalgam or resin-based composite restorations in the same patient, one obtained with the toothpick technique (group TT), and the other from homologous tooth restoration with the tray technique (group TR). This method involves only a direct impression on the occlusal surfaces by a section of a fluoride tray with trypticase yeast extract cysteine sucrose with bacitracin (TYCSB) agar previously prepared and solidified. The samples were incubated at 37 ºC for 48 h and the colony-forming units (CFU) were counted. The results were statistically analyzed with SPSS software using the linear regression method at 95% confidence level. RESULTS: TR was able to isolate S. mutans, and there was a significant positive correlation (r=0.95) with TT. There was no significant correlation between TR and control group S (r=0.47). CONCLUSIONS: TR was able to isolate and count S. mutans from the dental biofilm of dental restorations with a significant correlation with the TT group.

OBJETIVO: o uso de diferentes fontes de luz como auxiliar no clareamento de consultório tem sido descrita na literatura.Assim, o objetivo deste estudo foi avaliar as alterações da cor dos dentes após a aplicação de técnicas de clareamento com diferentes produtos, com e sem ativação por um sistema de LED-laser. METODOLOGIA: Vinte-quatro superfícies de dentes bovinos foram submetidas a três técnicas de clareamento com dois agentes clareadores disponíveis comercialmente à base de peróxido de carbamida a 35% (n=8). Os espécimes foram inicialmente imersos em vinho tinto por 48 ha 37°C, e submetidos às técnicas de clareamento. As alterações de cor foram mensuradas antes e após o manchamento, bem como imediatamente e 24 hs após as técnicas de clareamento, por meio de dois diferentes métodos de avaliação da cor: software ScanWhite V1.1 e espectrofotômetro intra-oral Vita Easyshade. Os dados foram analisados pelos testes de ANOVA e Kruskal-Wallis. RESULTADOS: A análise estatística não apontou diferenças significantes entre os diferentes grupos testados, independentemente do período de avaliação, método de avaliação ou uso do sistema LED-laser. CONCLUSÃO: Os resultados sugeriram que o uso da luz não influenciou nas mudanças de cor.

PURPOSE: The use of different light sources as an adjunct to in-office bleaching has been questioned. Thus, the aim of this study was to evaluate the color changes of teeth after application of bleaching techniques with different products, with and without activation by a LED-laser system. METHODS: Twenty-four bovine teeth surfaces were submitted to three bleaching techniques with two commercially available 35% hydrogen peroxide bleaching agents (n=8). The specimens were immersed in red wine for 48 h at 37°C and submitted to the bleaching techniques. Color changes were measured before and after staining as well as immediately after and 24 h after the bleaching treatments, with two different methods of color evaluation, software ScanWhite V1.1 and intra-oral spectrophotometer (Vita Easyshade). Data were analyzed by ANOVA and Kruskal-Wallis test. RESULTS: The statistical analysis showed that there was no statistically significant difference at 5% of significance level between the different groups, independently of the evaluation time, evaluation methods or the use of LED-laser systems. CONCLUSION: The results suggested that the use of light in the bleaching techniques did not influence the color changes.

OBJECTIVE: The aim of this study was to evaluate the fracture strength and failure mode of flared bovine roots restored with different intraradicular posts. MATERIAL AND METHODS: Fifty bovine incisors with similar dimensions were selected and their roots were flared until 1.0 mm of dentin wall remained. Next, the roots were allocated into five groups (n=10): GI- cast metal post-and-core; GII- fiber posts plus accessory fiber posts; GIII- direct anatomic post; GIV- indirect anatomic post and GV- control (specimens without intraradicular post). A polyether impression material was used to simulate the periodontal ligament. After periodontal ligament simulation, the specimens were subjected to a compressive load at a crosshead speed of 0.5 mm/min in a servo-hydraulic testing machine (MTS 810) applied at 135º to the long axis of the tooth until failure. The data (N) were subjected to ANOVA and Tukey's post-hoc test (α=0.05). RESULTS: GI and GIV presented higher fracture strength (p<0.05) than GII. GIII presented intermediate values without statistically significant differences (p>0.05) from GI, GII and GIV. Control specimens (GV) produced the lowest fracture strength mean values (p<0.05). Despite obtaining the highest mean value, GI presented 100% of unfavorable failures. GII presented 20% of unfavorable failures. GIII, GIV and GV presented only favorable failures. CONCLUSIONS: Although further in vitro and in vivo studies are necessary, the results of this study showed that the use of direct and indirect anatomic posts in flared roots could be an alternative to cast metal post-and-core.

O uso de condicionadores ácidos para desmineralizar a superfície dental e expor a rede de fibras colágenas para interdifusão dos monômeros adesivos e conseqüente formação da camada híbrida tem sido considerado o mais eficiente mecanismo de adesão dos agentes de união. O objetivo deste estudo foi comparar a resistência de união à dentina de três sistemas adesivos, dois autocondicionantes (Clearfil SE Bond - CSEB e One Up Bond F - OUBF) e um de condicionamento total (Single Bond - SB), sob três diferentes condições de substrato dentinário (úmido, seco e reidratado). Noventa terceiros molares humanos recém-extraídos foram cortados na superfície oclusal, para se remover o esmalte e formar uma parede plana de dentina. Os espécimes foram restaurados com resina composta (Filtek Z250) e submetidos ao teste de resistência de união à tração (TBS) em uma MTS 810. As médias foram submetidas à ANOVA a dois critérios e ao teste de Tukey (p = 0,05). A dentina úmida apresentou os maiores valores de TBS para os sistemas adesivos SB e CSEB. A dentina seca e a reidratada apresentaram TBS significativamente menor quando foi empregado SB. OUBF não apresentou resultados influenciados pela condição do substrato dentinário, tendo produzido TBS similares para os diferentes tratamentos de superfície.

The use of acid etchants to produce surface demineralization and collagen network exposure, allowing adhesive monomers interdiffusion and consequently the formation of a hybrid layer, has been considered the most efficient mechanism of dentin bonding. The aim of this study was to compare the tensile bond strength to dentin of three adhesive systems, two self-etching ones (Clearfil SE Bond - CSEB and One Up Bond F - OUBF) and one total-etching one (Single Bond - SB), under three dentinal substrate conditions (wet, dry and re-wet). Ninety human, freshly extracted third molars were sectioned at the occlusal surface to remove enamel and to form a flat dentin wall. The specimens were restored with composite resin (Filtek Z250) and submitted to tensile bond strength testing (TBS) in an MTS 810. The data were submitted to two-way ANOVA and Tukey's test (p = 0.05). Wet dentin presented the highest TBS values for SB and CSEB. Dry dentin and re-wet produced significantly lower TBS values when using SB. OUBF was not affected by the different conditions of the dentin substrate, producing similar TBS values regardless of the surface pretreatments.