Surface roughness of resin-based composites subjected to professional prophylaxis / Rugosidade de superfície de resinas compostas após profilaxia profissional

Objetivo: Avaliar o efeito de dois métodos de profilaxia sobre a rugosidade superficial de diferentes resinas compostas. Materiais e Métodos: Dez amostras (7 mm x 2 mm) foram confeccionadas para cada resina testada: MH - resina microhíbrida (viscosidade regular - Opallis); NH ­ resina nanohíbrida (viscosidade regular - Vittra APS); BF ­ resina bulk fill (alta viscosidade - Opus Bulk Fill); MHF ­ resina fluida microhíbrida (Opallis flow); e OS ­ resina nanohíbrida camaleão (viscosidade regular - Vittra Unique). Os valores iniciais de rugosidade (Rai) foram obtidos para cada amostra e então subdivididas em dois grupos (n = 5) seguindo o método de profilaxia: SB ­ jato de bicarbonato de sódio (125µm, 30 s, 10 mm de distância, 2 bar); e PP ­ profilaxia com pasta de pedra-pomes e escova rotatória (30 s, 3000 rpm e pressão de 150 g). Após, uma nova medida de Ra (Raf) foi obtida, e a diferença calculada (ΔRa). Os dados foram analisados pelo teste ANOVA três fatores e teste de Bonferroni, e a diferença de rugosidade (ΔRa) pelo teste Anova dois fatores e teste de Tukey (p<0,05). Resultados: MHF apresentou maior rugosidade após profilaxia com jato de bicarbonato, enquanto para NH a abrasão com pedra pomes foi mais deletéria. Para os demais grupos não houve diferença. Discussão: A alteração na rugosidade promovida pela profilaxia é material-dependente. Conclusão: A profilaxia profissional com jato de bicarbonato ou abrasão com pedra-pomes induziu alterações na rugosidade das resinas.

Aim: This study evaluated the effect of two prophylaxis methods over the surface roughness of different resin composites. Materials and Methods: Ten disc-shaped specimens (7 mm x 2 mm) were made for each composite tested: MH - microhybrid composite with regular viscosity (Opallis); NH ­ nanohybrid composite with regular viscosity (Vittra APS); BF ­ high-viscosity bulk fill composite (Opus Bulk Fill); MHF - microhybrid flowable composite (Opallis flow); and OS ­ nanohybrid one-shade composite with regular viscosity (Vittra Unique). Initial roughness (Ra) values were obtained from each sample, and then they were divided into two groups (n = 5) following the prophylaxis method: SB ­ prophylaxis with sodium bicarbonate powder (125µm grain) using an air-powder polishing device (30 s application distanced 10 mm with 2 bar); and PP ­ prophylaxis with pumice paste and rotatory brush (30 s, 3000 rpm and pressure of 150 g). After that, a new Ra measurement (Raf) was obtained, and the difference was calculated (ΔRa). Data were compared using Three-way ANOVA followed by Bonferroni teste and the Ra difference (ΔRa) was analyzed by Two-way ANOVA followed by the Tukey test (p<0.05). Results: MHF presented higher Ra values after receiving prophylaxis with SB, while for NH, the abrasion with pumice increased the Ra, and for the other groups, no differences were found. Discussion: Alteration promoted by prophylaxis is material dependent. Conclusion: Professional prophylaxis with a bicarbonate jet or abrasion with pumice-based paste can induce changes in the composites' roughness.

Rugosidade de superfície de resinas compostas após profilaxia profissional / Surface roughness of resin-based composites subjected to professional prophylaxis

Objetivo: Avaliar o efeito de dois métodos de profilaxia sobre a rugosidade superficial de diferentes resinas compostas. Materiais e Métodos: Dez amostras (7 mm x 2 mm) foram confeccionadas para cada resina testada: MH - resina microhíbrida (viscosidade regular - Opallis); NH ­ resina nanohíbrida (viscosidade regular - Vittra APS); BF ­ resina bulk fill (alta viscosidade - Opus Bulk Fill); MHF ­ resina fluida microhíbrida (Opallis flow); e OS ­ resina nanohíbrida camaleão (viscosidade regular - Vittra Unique). Os valores iniciais de rugosidade (Rai) foram obtidos para cada amostra e então subdivididas em dois grupos (n = 5) seguindo o método de profilaxia: SB ­ jato de bicarbonato de sódio (125µm, 30 s, 10 mm de distância, 2 bar); e PP ­ profilaxia com pasta de pedra-pomes e escova rotatória (30 s, 3000 rpm e pressão de 150 g). Após, uma nova medida de Ra (Raf) foi obtida, e a diferença calculada (ΔRa). Os dados foram analisados pelo teste ANOVA três fatores e teste de Bonferroni, e a diferença de rugosidade (ΔRa) pelo teste Anova dois fatores e teste de Tukey (p<0,05). Resultados: MHF apresentou maior rugosidade após profilaxia com jato de bicarbonato, enquanto para NH a abrasão com pedra pomes foi mais deletéria. Para os demais grupos não houve diferença. Discussão: A alteração na rugosidade promovida pela profilaxia é material-dependente. Conclusão: A profilaxia profissional com jato de bicarbonato ou abrasão com pedra-pomes induziu alterações na rugosidade das resinas.

Aim: This study evaluated the effect of two prophylaxis methods over the surface roughness of different resin composites. Materials and Methods: Ten disc-shaped specimens (7 mm x 2 mm) were made for each composite tested: MH - microhybrid composite with regular viscosity (Opallis); NH ­ nanohybrid composite with regular viscosity (Vittra APS); BF ­ high-viscosity bulk fill composite (Opus Bulk Fill); MHF - microhybrid flowable composite (Opallis flow); and OS ­ nanohybrid one-shade composite with regular viscosity (Vittra Unique). Initial roughness (Ra) values were obtained from each sample, and then they were divided into two groups (n = 5) following the prophylaxis method: SB ­ prophylaxis with sodium bicarbonate powder (125µm grain) using an air-powder polishing device (30 s application distanced 10 mm with 2 bar); and PP ­ prophylaxis with pumice paste and rotatory brush (30 s, 3000 rpm and pressure of 150 g). After that, a new Ra measurement (Raf) was obtained, and the difference was calculated (ΔRa). Data were compared using Three-way ANOVA followed by Bonferroni teste and the Ra difference (ΔRa) was analyzed by Two-way ANOVA followed by the Tukey test (p<0.05). Results: MHF presented higher Ra values after receiving prophylaxis with SB, while for NH, the abrasion with pumice increased the Ra, and for the other groups, no differences were found. Discussion: Alteration promoted by prophylaxis is material dependent. Conclusion: Professional prophylaxis with a bicarbonate jet or abrasion with pumice-based paste can induce changes in the composites' roughness.

Efeito protetor de enxaguatórios com diferentes fluoretos utilizados previamente aos desafios erosivos/abrasivos em esmalte e dentina / Protective effect of solutions with different fluorides used previously to erosive/abrasive challenges in enamel and dentin

Aim: To evaluate the protection offered by commercial mouthwashes containing sodium fluoride or stannous chloride associated with sodium fluoride to enamel and dentin, prior to erosive and abrasive cycling. Materials and Methods: Enamel and dentin samples were obtained from bovine incisors and subdivided into 3 groups (n=10), according to the fluoridated ingredient tested: FS (sodium fluoride - NaF (225 ppm)); FE (tin fluoride - NaF + SnCl2 (800 ppm Sn2+)); control (distilled water). The samples were submitted to an erosive/abrasive cycle with immersion in citric acid (lemon soda for 5 min, 4×/day, 5 days, with remineralization intervals in artificial saliva for 60 min). Abrasion was carried out with an electric brush (200 g/force) after the first and last cycles, 2x/day, and immediately afterward immersed in the tested solutions. Structure loss was obtained by optical profilometry. The data were subjected to analysis of variance and multiple comparison for each substrate separately. Results: For enamel there was a difference between the groups (p = 0.027), with the FS showing less loss of structure compared to the control 2.02 (±0.48). The FE group showed similar loss to the control and FS 2.32 (±0.58)ab. For dentin there was a difference between the groups (p = 0.011), with FE showing less loss of structure compared to the other groups, 0.82 (25% - 0.34; 75% - 0.95). Discussion: The protection of fluorides in erosive/abrasive challenges depends on the type and dental substrate. Conclusion: Mouthwash with sodium fluoride prior to erosive/abrasive challenges caused less loss of enamel surface, while for dentin, sodium fluoride associated with stannous chloride caused less loss of structure.

Objetivo: Avaliar a proteção oferecida por soluções para bochecho de fluoreto de sódio ou cloreto de estanho associado ao fluoreto de sódio ao esmalte e à dentina, previamente à ciclagem erosiva e abrasiva. Materiais e Métodos: Amostras de esmalte e dentina foram obtidas a partir de incisivos bovinos e subdivididas em 3 grupos (n=10), de acordo com o princípio ativo fluoretado testado: FS (fluoreto de sódio - NaF (225 ppm)); FE (fluoreto de estanho - NaF + SnCl2 (800 ppm Sn2+)); controle (água destilada). As amostras foram submetidas a um ciclo erosivo/abrasivo com imersão em ácido cítrico (refrigerante de limão por 5 min, 4×/dia, 5 dias, com intervalos de remineralização em saliva artificial por 60 min). A abrasão foi realizada com escova elétrica (200 g/força) após o primeiro e o último ciclos, 2×/dia, e logo em seguida imersos nas soluções testadas. A perda de estrutura foi obtida por perfilometria óptica. Os dados foram submetidos à análise de variância e comparação múltipla para cada substrato separadamente. Resultados: Para esmalte houve diferença entre os grupos (p = 0,027), tendo o FS apresentados menor perda de estrutura comparado ao controle 2,02 (±0,48). O grupo FE apresentou perda similar ao controle e ao FS 2,32 (±0,58)ab. Para dentina houve diferença entre os grupos (p = 0,011), sendo que o FE apresentou menor perda de estrutura comparado aos demais grupos 0,82 (25% - 0,34; 75% - 0,95). Discussão: A proteção dos fluoretos em desafios erosivos/abrasivos depende do tipo e do substrato dental. Conclusão: O bochecho com fluoreto de sódio previamente aos desafios erosivos/abrasivos apresentou menor perda de superfície em esmalte, enquanto para dentina o fluoreto de sódio associado ao cloreto de estanho apresentou menor perda de estrutura.

Influence of the combined effect of desensitizing dentifrices and universal adhesives on dentin bond strength under erosive conditions.

OBJECTIVE: This study aimed to evaluate whether the use of desensitizing dentifrices containing obliterating agents can affect bond strength of eroded/abraded dentin. METHODOLOGY: A total of 100 dentin samples were obtained from human molars. The teeth were cut into 3 mm-thickness discs and allocated in five groups (n=20), according to the toothpaste used: WoF - abrasion with fluoride-free toothpaste (Cocoricó); Arg - toothpaste containing arginine (Colgate Sensitive Pro-Relief); Nov - calcium sodium phosphosilicate toothpaste (Sensodyne Repair and Protect); SnF - fluoride-containing toothpaste (AmF/SnCl2/SnF2 - Elmex Erosion); and Control (no erosive/abrasive process). The erosive/abrasive cycle consisted of immersion in citric acid (1%, pH 2.6, 5 min, 4×/day) and abrasion (2×/day, 120-20 sec abrasion, 100 sec immersion) with each toothpaste. During intervals, samples were immersed in artificial saliva. This cycle was performed for five days. Two resin cylinders (2 mm in diameter) were constructed on each sample for the shear bond strength test using a universal adhesive system. The self-etch and etch-and-rinse (Scotchbond Universal) strategies were employed, each in half of the total sample (n=10). Bond strength (MPa) was measured in a shear test and failure modes were assessed with a stereomicroscope. Statistical analysis was performed using the two-way analysis of variance (ANOVA) and Tukey tests (p<0.05). RESULTS: A statistically significant difference was found between the adhesive strategies tested (p<0.001), with the self-etching form showing higher values than the etch-and-rinse. Moreover, no significant differences were observed between the tested toothpastes (p=0.750) and interactions (p=0.438). CONCLUSION: The use of toothpaste containing obliterating agents does not affect bond strength to dentin subjected to erosive/abrasive conditions when a universal adhesive is used. However, the self-etch strategy might be preferred for eroded/abraded dentin.

Influence of the combined effect of desensitizing dentifrices and universal adhesives on dentin bond strength under erosive conditions

Abstract Objective This study aimed to evaluate whether the use of desensitizing dentifrices containing obliterating agents can affect bond strength of eroded/abraded dentin. Methodology A total of 100 dentin samples were obtained from human molars. The teeth were cut into 3 mm-thickness discs and allocated in five groups (n=20), according to the toothpaste used: WoF - abrasion with fluoride-free toothpaste (Cocoricó); Arg - toothpaste containing arginine (Colgate Sensitive Pro-Relief); Nov - calcium sodium phosphosilicate toothpaste (Sensodyne Repair and Protect); SnF - fluoride-containing toothpaste (AmF/SnCl2/SnF2 - Elmex Erosion); and Control (no erosive/abrasive process). The erosive/abrasive cycle consisted of immersion in citric acid (1%, pH 2.6, 5 min, 4×/day) and abrasion (2×/day, 120-20 sec abrasion, 100 sec immersion) with each toothpaste. During intervals, samples were immersed in artificial saliva. This cycle was performed for five days. Two resin cylinders (2 mm in diameter) were constructed on each sample for the shear bond strength test using a universal adhesive system. The self-etch and etch-and-rinse (Scotchbond Universal) strategies were employed, each in half of the total sample (n=10). Bond strength (MPa) was measured in a shear test and failure modes were assessed with a stereomicroscope. Statistical analysis was performed using the two-way analysis of variance (ANOVA) and Tukey tests (p<0.05). Results A statistically significant difference was found between the adhesive strategies tested (p<0.001), with the self-etching form showing higher values than the etch-and-rinse. Moreover, no significant differences were observed between the tested toothpastes (p=0.750) and interactions (p=0.438). Conclusion The use of toothpaste containing obliterating agents does not affect bond strength to dentin subjected to erosive/abrasive conditions when a universal adhesive is used. However, the self-etch strategy might be preferred for eroded/abraded dentin.

The ability of different formulations of artificial saliva to protect dentin from erosive wear / Ação protetora de diferentes formulações de saliva artificial no desgaste erosivo

Objective: Evaluate the protective effect of artificial saliva formulations associated or not with mucin on dentin. Materials and Methods: Bovine dentin specimens were randomly allocated to 10 groups (n = 20) according to the artificial saliva tested and the presence or absence of mucin: Amaechi et al. (1998); Klimek et al. (1982); Vieira et al. (2005) and Eisenburger et al. (2001) and deionized water (control). Samples were submitted to an erosive cycle consisting of two immersions of 120 min in the saliva, followed by 1 min in hydrochloric acid solution, and new storage in saliva for 120 min. Surface loss (µm) was measured before and after the cycle. Data were analyzed using 2-way ANOVA and Tukey's test (p < 0.05). Results: A significant difference was observed for the saliva formulation but not for the presence of mucin. The deionized water provided the highest surface loss and the Eisenburger's saliva formulation the lowest. The groups testing the Amaechi, Klimek, and Vieira saliva did not present significant differences. Conclusion: Eisenburger's saliva formulation provides a higher protective effect against dentin erosion. The presence of mucin did not increase the erosion-preventive effect of artificial saliva formulations. (AU)

Objetivo: Avaliar o efeito protetor de formulações de saliva artificial associadas ou não à mucina sobre a dentina submetida a erosão. Material e Métodos: Espécimes de dentina bovina foram alocados em 10 grupos (n = 20) de acordo com a saliva testada e a presença ou ausência de mucina: . Amaechi et al. (1998); Klimek et al. (1982); Vieira e cols. (2005), Eisenburger et al (2001) e agua deionizada (controle). As amostras foram submetidas a um ciclo erosivo composto por duas imersões de 120 min na saliva, seguidas de 1 min em solução de ácido clorídrico e novo armazenamento na saliva por 120 min. A perda de superfície (µm) foi medida antes e depois do ciclo. Os dados foram analisados usando ANOVA 2 fatores e teste de Tukey (p <0,05). Resultados: Foi observada diferença significativa para a formulação de saliva, mas não para a presença de mucina. A água deionizada proporcionou a maior perda de superfície e a formulação de saliva de Eisenburger a menor. Os grupos que testaram a saliva Amaechi, Klimek e Vieira não apresentaram diferenças significativas entre si. Conclusão: A formulação de saliva de Eisenburger fornece o maior efeito protetor contra a erosão dentinária e a presença de mucina não aumentou o efeito preventivo de erosão de formulações de saliva artificial (AU).

Bonding performance of universal adhesives with concomitant use of silanes to CAD/CAM blocks / Associação de adesivos universais com silanos na adesão em blocos de CAD/CAM

ABSTRACT Objective: This study assessed whether the use of a silane coupling agent influence the bond strength of two universal adhesives to ceramic or resin CAD/CAM blocks. Methods: Forty-eight samples were obtained from each resin nano-ceramic hybrid block (RCBs) and lithium disilicate ceramic blocks (LD). Samples were treated with silane with MDP (Monobond - S-MDP), silane without MDP (Prosil - PS), and no silane application (Control - Ctr) followed by universal adhesive with silane (UAS) and without silane (UA) (n=8). Three polyurethane tubes (1.5 mm of internal diameter) were positioned in each sample treated surface and filled with a dual cured resin cement. Bond strength was assessed by microshear bond strength test and failure analysis was performed for all samples. Results: For the RCBs, UAS presented the highest bond strength values (p=0.004). Silane application was not significant in bond strength values (p=0.444). For LD, silane application was significant in bond strength values (p<0.001), but the adhesive was not (p=0.066). Failure analysis showed high prevalence of adhesive failures for both substrates. Conclusion: A silane-containing universal adhesive promoted the best bond strength results to the resin nano-ceramic hybrid block. For bonding to a glass-ceramic CAD/CAM material, additional silane (without MDP) application presented the best results.

RESUMO Objetivo: Este estudo avaliou se o uso de um agente de união silano influencia na resistência de união de dois adesivos universais a blocos CAD/CAM cerâmicos ou resinosos. Métodos: Quarenta e oito amostras foram obtidas de blocos resinosos (RCBs) e cerâmicos de dissilicato de lítio (LD). As amostras foram tratadas com silano contendo: MDP (Monobond - S-MDP), silano sem MDP (Prosil - PS) ou sem aplicação de silano (Control - Ctr) seguido de adesivo universal com silano (UAS) ou sem silano (UA) (n=8). Três tubos de poliuretano (1,5 mm de diâmetro interno) foram posicionados em cada superfície tratada da amostra e preenchidos com um cimento resinoso dual. A resistência de união foi avaliada pelo teste de microcisalhamento e a análise de falha foi realizada para todas as amostras. Resultados: Para os RCBs, UAS apresentou os maiores valores de resistência de união (p=0,004). A aplicação de silano não foi significativa nos valores de resistência adesiva (p=0,444). Para LD, a aplicação de silano foi significativa nos valores de resistência de união (p<0,001), mas o adesivo não (p=0,066). A análise de falhas mostrou alta prevalência de falhas adesivas para ambos os substratos. Conclusão: O adesivo universal contendo silano promoveu os melhores valores de resistência adesiva ao bloco de resina. Para o bloco cerâmico, a aplicação adicional de silano (sem MDP) apresentou melhores resultados.

Restoration of teeth with customized CAD/CAM glass fiber posts: report of 2 cases.

This article presents 2 cases in which computer-aided design/computer-aided manufacturing (CAD/CAM) was used to fabricate glass fiber posts to restore an anterior tooth and a posterior tooth with severe coronal destruction. In the past decade, CAD/CAM technology has improved, allowing high-precision milling of customized glass fiber posts. This can enhance the biomechanical behavior of the restoration, as the post and core are milled in a single unit, decreasing the risk of failure near the core junction or in the body of the core. The customized post also provides better adaptation and requires a thinner layer of cement, thus minimizing voids. In case 1, the patient had a severely damaged maxillary right canine with a ferrule from a previous restoration. In case 2, the patient presented with a mandibular left first molar exhibiting severe coronal destruction. In both cases, impressions of the root canal were scanned with a bench scanner, and the posts were fabricated using a glass fiber material designed for CAD/CAM technology. A self-adhesive resin cement was used to cement the posts in the root canals, and a metal-free crown (case 1) and overlay (case 2) were fabricated and placed. Satisfactory retention and esthetics were achieved, and both patients was pleased by the final results. These cases demonstrate the viability of CAD/CAM to restore endodontically treated teeth, and this technology can be an option for dentists interested in using a digital workflow. The longevity of the posts produced via this technique needs to be evaluated in clinical trials.

Assessment of the Oral Health Impact Profile (OHIP-14) improvement of different treatments for dentin hypersensitivity in noncarious cervical lesions-a randomized clinical study.

OBJECTIVES: To assess the improvement on oral health-related quality of life (OHRQoL) of individuals with cervical dentin hypersensitivity (CDH) with the noncarious cervical lesion (NCCLs) subjected to different treatments. MATERIAL AND METHODS: A single-blind randomized clinical trial was conducted with patients (n = 74) randomly allocated into three groups according to the treatment performed: PO, potassium oxalate (Oxa-Gel BF); LL, low-power laser irradiation; and POLL, potassium oxalate (Oxa-Gel BF) associated with low-power laser irradiation. The treatments were applied in four steps, weekly. The questionnaire Oral Health Impact Profile (OHIP-14) was applied before initiating and immediately after the fourth session. The greater the sum of the score, the smaller the measurement of OHRQoL. RESULTS: The total mean values of the variables at the final moment were significantly lower than the initial one for all dimensions (p value ranging from < 0.001 to 0.006). Furthermore, the OHIP-14 scores final analysis between the groups indicated that the POLL group compared to LL had a significantly lower final score for the functional limitation (p = 0.009), physical pain (p = 0.049), and psychological discomfort (p = 0.035) dimensions and that group PO compared to group LL had a significantly lower final score for the functional limitation dimension (p = 0.024). CONCLUSIONS: There was a reduction in the OHIP-14 score for all dimensions, indicating an improvement in patients' quality of life after the use of desensitizing therapies. Patients in group LL had a higher functional limitation, physical pain, and psychological discomfort. CLINICAL RELEVANCE: This study indicated improvement of desensitizing therapies for CDH to improve patients' OHRQoL. TRIAL REGISTRATION: This trial was registered in the Brazilian Clinical Trials Registry Platform (REBEC protocol number RBR-4ybjmt).

Mechanical Properties of Experimental Composites with Different Photoinitiator.

OBJECTIVE: The effect of different photoinitiators on mechanical properties of experimental composites was evaluated. MATERIALS AND METHODS: Resin composites were formulated by using a blend of bisphenol A-glycidyl and triethylene glycol (50/50 wt%) dimethacrylate monomers, and 65 wt% of barium aluminium silicate and silica filler particles. Photoinitiators used were 0.2% camphorquinone (CQ) and 0.8% co-initiator (DMAEMA); 0.2% phenyl-propanedione and 0.8% DMAEMA; 0.1% CQ + 0.1% phenyl propanedione and 0.8% DMAEMA; 0.42% mono(acyl)phosphine oxide (MAPO); and 0.5% bis(acyl)phosphine oxide (BAPO). Specimens (n = 10) were light cured by using a multiple-emission peak light-emitting diode for 20 seconds at 1,200 mW/cm2 of irradiance and Knoop hardness and plasticization, depth of cure, flexural strength, and elastic modulus were evaluated. Data were statiscally analyzed at significance level of α = 5%. RESULTS: Experimental composites containing MAPO and BAPO photoinitiators showed the highest values of flexural strength, elastic modulus, top surface hardness, and lower hardness reduction caused by alcohol compared with CQ. Composites containing CQ and PPD showed similar results, except for depth of cure and hardness of bottom surface. CONCLUSION: BAPO and MAPO showed higher flexural strength, elastic modulus, hardness on top surface, and lower polymer plasticization to CQ.

Bonding Performance for Repairs Using Bulk Fill and Conventional Methacrylate Composites.

This study compared the bond strength of a composite repair made with a bulk fill composite and a conventional one using different surface treatments. Specimens were prepared as truncated cones (bases: 4 mm × 2 mm, height: 4 mm) using a bulk fill (OBFa: Filtek One) or a conventional resin (FTKa: Filtek Z250) (n = 66). They were artificially aged (10,000 cycles, 5°C-55°C, 30 sec) and subdivided according to surface treatments: NT-no treatment (control), Abr-abrasion with a diamond tip, and sand-sandblasting with aluminum oxide (50 µm). Treatments were performed over the smaller diameter surface, followed by adhesive (Scothbond Universal) application. A new specimen with similar dimensions was constructed over it using either the OBF or the FTK, totaling 12 groups (n = 11). Bond strength was assessed by tensile test. The data were submitted to two-way ANOVA separately for OBFa and FTKa, followed by Tukey's test (p < 0.05). For the aged OBFa groups, there was significant differences for composite type and surface treatment, with higher values of bond strength when repaired with the same material (OBFa/OBF > OBFa/FTK), and sandblasting and bur abrasion presented higher values compared to the control group (NT). For the aged FTKa groups, there were no differences for the composite or surface treatment. Therefore, the bulk fill resin composite tested present better repair performance when the same composite was used, while the conventional resin composite was less influenced by the material and the surface treatment performed.

Protection of calcium silicate/sodium phosphate/fluoride toothpaste with serum on enamel and dentin erosive wear.

OBJECTIVE: To evaluate the effect of a toothpaste containing calcium silicate/sodium phosphate/fluoride associated or not to the boost serum (BS) against erosive tooth wear (ETW) on enamel and dentin. METHODOLOGY: Bovine enamel and dentin specimens were subjected to an erosion-abrasion cycling model (1% citric acid - pH 3.6 -2 min / artificial saliva - 60 min, 4×/day, 5 days). Toothbrushing was performed for 15 s (2 min exposed to slurry), 2×/day, with the toothpastes (n=10): control without fluoride (Weleda), Arg/Ca/MFP (Colgate Pro-Relief), Si/PO4/MFP (Regenerate-Unilever), and Si/PO4/MFP/BS (Si/PO4/MFP with dual BS - Advanced Enamel Serum-Unilever). The effect of treatments on the eroded tissues was assessed by surface microhardness in the first day, and surface loss (SL) resulting from ETW was evaluated by profilometry (µm) after three and five days. Additional dentin specimens (n=5/group) were subjected to 20,000 brushing cycles to verify the abrasivity of the toothpastes. Data were subjected to ANOVA and correlation tests (5%). RESULTS: For enamel, no difference in microhardness was observed among the treated groups, and similar SL was obtained after 5 days. For dentin, Si/PO4/MFP/BS resulted in higher microhardness values, but none of the groups presented significantly lower SL than the control. There was no significant correlation between SL and abrasiveness. CONCLUSION: The calcium silicate/sodium phosphate toothpaste and serum increased microhardness of eroded dentin, but they did not significantly reduce enamel and dentin loss compared to the non-fluoride control toothpaste. The abrasiveness of the toothpastes could not predict their effect on ETW.

The effects of polishing techniques on surface roughness and gloss of different composites.

The aim of this study was to evaluate the effects of different polishing techniques on the surface roughness and gloss of various composites. A total of 360 composite cylinders (6 mm in diameter and 2 mm in thickness) were made using a silicone matrix and 1 of the following 6 restorative materials (n = 60): Admira Fusion, GrandioSO, Filtek Supreme, Filtek Z250, TPH Spectra ST, and Herculite Classic. The composite specimens were cured and then immersed in water for 24 hours. The baseline roughness was standardized with 600-grit silicon carbide paper used in a polishing device for 30 seconds. The specimens were divided into 6 subgroups (n = 10) according to the polishing technique: abrasive discs (Sof-Lex); abrasive discs (Sof-Lex) and diamond paste (Diamond Excel); abrasive rubber point (Dimanto); silicon carbide polishing brush (OptiShine); rubber spiral wheels (Sof-Lex Spiral Wheels - Diamond Polishing System); or sequential application of polishing pastes (Diamond ACI and ACII). After polishing was completed, the surface roughness and gloss were measured, and the data underwent 2-way analysis of variance and the Tukey test (P < 0.05). Statistically significant differences were observed for roughness (P < 0.001) and gloss (P < 0.001) for both factors analyzed (composite material and polishing technique). Admira Fusion exhibited the highest roughness and lowest gloss values of all of the composites, and Filtek Supreme exhibited the lowest roughness and highest gloss values. Sof-Lex Spiral Wheels and OptiShine polishing brush exhibited lower roughness and higher gloss than the other polishing techniques. The effects of different polishing techniques were material dependent, but all systems tested provided clinically acceptable results. The use of a single polishing technique for all types of composite materials might result in undesirable clinical outcomes.

Minimal intervention in dentistry: which is the best approach for silorane composite restoration repairs?

BACKGROUND: This study aimed to evaluate surface treatments, adhesives and composites for repairing silorane based restorations. MATERIAL AND METHODS: One hundred and twenty truncated cones (2 mm smaller diameter and 4 mm larger diameter) made of silorane composite were divided in 12 groups according with the surface treatment (diamond bur and oxide aluminum abrasion), the adhesive (Adper Scothbond Multipurpose (3M ESPE), Ecusit (Voco) and Filtek P90 Adhesive (3M ESPE)). Each group was subdivided in two according with the composite used for repair (methacrylate and silorane). The repair was made with a second truncated cone build over the first one and bond strength assssed by tensile strength. Data were submitted to ANOVA 3-way and Tukey's test (p<0.05). RESULTS: There was difference only for the adhesives and the composites, with conventional adhesives (Adper Scothbond Mutipurpose) and methacrylate-based composites (Filtek Z350) presenting superior tensile strength compared to the silorane ones (P90 Adhesive system and composite). CONCLUSIONS: Therefore, it must be concluded that silorane composite can be repaired with methacrylate base composites and adhesives. Key words:Silorane composites, composites, bond strength, minimal intervention.

Protection of calcium silicate/sodium phosphate/fluoride toothpaste with serum on enamel and dentin erosive wear

Abstract Objective To evaluate the effect of a toothpaste containing calcium silicate/sodium phosphate/fluoride associated or not to the boost serum (BS) against erosive tooth wear (ETW) on enamel and dentin. Methodology Bovine enamel and dentin specimens were subjected to an erosion-abrasion cycling model (1% citric acid - pH 3.6 -2 min / artificial saliva - 60 min, 4×/day, 5 days). Toothbrushing was performed for 15 s (2 min exposed to slurry), 2×/day, with the toothpastes (n=10): control without fluoride (Weleda), Arg/Ca/MFP (Colgate Pro-Relief), Si/PO4/MFP (Regenerate-Unilever), and Si/PO4/MFP/BS (Si/PO4/MFP with dual BS - Advanced Enamel Serum-Unilever). The effect of treatments on the eroded tissues was assessed by surface microhardness in the first day, and surface loss (SL) resulting from ETW was evaluated by profilometry (μm) after three and five days. Additional dentin specimens (n=5/group) were subjected to 20,000 brushing cycles to verify the abrasivity of the toothpastes. Data were subjected to ANOVA and correlation tests (5%). Results For enamel, no difference in microhardness was observed among the treated groups, and similar SL was obtained after 5 days. For dentin, Si/PO4/MFP/BS resulted in higher microhardness values, but none of the groups presented significantly lower SL than the control. There was no significant correlation between SL and abrasiveness. Conclusion The calcium silicate/sodium phosphate toothpaste and serum increased microhardness of eroded dentin, but they did not significantly reduce enamel and dentin loss compared to the non-fluoride control toothpaste. The abrasiveness of the toothpastes could not predict their effect on ETW.

Protective effect of fluorides on erosion and erosion/abrasion in enamel: a systematic review and meta-analysis of randomized in situ trials.

OBJECTIVES: To evaluate the effects of different fluoride types and vehicles when compared to water or placebo, on prevention of enamel erosion and erosive tooth wear progression. DESIGN: A systematic review followed by meta-analysis of randomized in situ trials was conducted. PubMeb, Scopus, Web of Science, LILACS, BBO, Scielo, EMBASE and CENTRAL electronic databases were searched. Studies with fluoride compounds (NaF, AmF, Sn, TiF4) and vehicles (toothpaste, mouth rinse, gel, and varnishes) compared to control (water or placebo) for control of enamel loss progression were included. Reviewers independently screened potentially eligible articles, extracted data, and assessed risk of bias. GRADE approach was used to rate the overall certainty of evidence for toothpastes and rinses under erosive/abrasive challenges. RESULTS: Thirty-two studies were elegible. Under erosive/abrasive challenges, enamel loss was significantly lower than control for NaF toothpastes [Mean difference(MD) -1.14; Confidence Interval(CI) -1.89 to -0.40] and Sn/associations [-6.02; -11.09 to -0.95], while no difference was found for AmF [-13.59; -39.7 to -12.52]. For mouth rinses, Sn/associations solutions were effective [-11.49; -16.62 to -6.37], but NaF showed no significant effect [-2.83; -8.04 to 2.38]. CONCLUSION: Overall, fluoride products are able to reduce enamel loss when compared to control, but results must be interpreted with caution. For toothpastes, NaF provided limited protection, with moderate evidence, while Sn/associations exhibited protective effect with low certainty of evidence. For rinses, NaF was not effective, with very low evidence, while the stannnous enriched fluorides offered higher protection regarding enamel erosion and erosive wear, with moderate certainty of evidence.

Enhancing the Anti-Erosive Properties of Fluoride and Stannous with the Polymer Carbopol.

This in vitro study investigated whether Carbopol 980 polymer could potentiate the anti-erosive effect of solutions containing sodium fluoride (F) and sodium fluoride associated with stannous chloride (FS). The dissolution of hydroxyapatite treated with the experimental solutions (F [500 ppm F-], F + Carbopol [0.1%], FS [500 ppm F- + 800 ppm Sn2+], FS + Carbopol) was evaluated. Deionized water was the negative control, and a commercial mouth rinse (AmF/NaF/SnCl2; 500 ppm F + 800 ppm Sn2+; Elmex® Erosion Protection) was the positive control. The solutions were also evaluated in an erosion-rehardening protocol, with two treatments per day, using bovine enamel specimens (n = 15) and human saliva. The acid challenge was performed using 0.3% citric acid (pH 2.6) for 2 min. Microhardness was measured at different times: baseline, after the first erosive challenge, after treatment, and after the second erosive challenge. Based on microhardness values, the demineralization, rehardening, and protective potentials were calculated. The alkali-soluble fluoride on enamel surfaces was also measured. Data were analyzed using ANOVA and Tukey tests (α = 0.05). Groups treated with FS + Carbopol showed the lowest hydroxyapatite dissolution and the highest rehardening and protective potentials. The measurement of alkali-soluble fluoride on enamel surfaces was also higher in the FS + Carbopol group. Carbopol was able to significantly increase the protective effect of the fluoridated solutions in addition to optimizing the adsorption of fluoride on the enamel surface.

Influence of thickness and translucency of lithium disilicate ceramic on degree of conversion of resinous materials.

BACKGROUND: In this study was assessed the degree of conversion (DC) of amine-free resin cements light cured through lithium disilicate-reinforced ceramics at different thicknesses and translucency. MATERIAL AND METHODS: Specimens were divided into 21 groups (n = 5) according to luting agent used: Variolink Esthetic LC (Light shade), RelyX Ultimate (A1 shade), and Filtek Z350 XT Flow (A1 shade); the ceramic translucency: low (LT) and high (HT); and the ceramic thickness: no ceramic (control), 0.5 mm, 1 mm, and 2 mm. A Teflon mold with (5 x 5 x 0.5 mm) was used to standardize the cement and over it the ceramic block from each group was placed. Set was cured using a polywave LED light (1200 mW/cm2 - Bluephase G2) for 40 s. FTIR spectra of uncured and cured materials was obtained and DC calculated from the height of the peaks 1610 and 1640 cm-1. Data were submitted to ANOVA followed by Tukey's test (α = 0.05). RESULTS: There was a significant difference for luting agents (p< 0.0001) and translucency (p = 0.025), but not for thickness (p = 0.73). Dual amine-free RelyX Ultimate showed the lowest DC values and higher translucency promoted higher DC. CONCLUSIONS: Dual amine-free cement showed the lowest monomer conversion and higher translucency ceramics promoted a higher DC. Key words:Ceramic, degree of conversion, resin cement, thickness, translucency.

Effects of calcium-phosphate, laser and adhesive on dentin permeability and bond strength.

OBJECTIVES: The present study examined a technique for reducing dentin permeability through the application of a calcium phosphate (CaP)-based desensitiser with a laser-assisted process and evaluated adhesive-dentin bond strength. Methods: Thirty dentin discs were divided into two groups according to whether the selected desensitiser (TeethMate; Kuraray Noritake) was used prior to dentin bonding. Each group was subdivided into three subgroups (n = 5): A- Adhesive (Single Bond Universal, 3M ESPE), AL- Adhesive + Laser (Nd:YAG 60 mJ) and LAL- Laser + Adhesive + Laser. Dentin permeability values (%) were recorded before and after desensitiser application. Resin composites were placed over the bonded specimens; the latter were aged prior to microtensile bond strength evaluation. Gelatinolytic activity within the hybrid layers was examined with in-situ zymography using confocal laser scanning microscopy. Data were analysed with ANOVA and Tukey test (α = 0.05). RESULTS: Significant differences in dentin permeability were identified for all groups (p = 0.00). Both laser treatment (p = 0.182) and desensitiser application (p = 0.687) did not significantly improve dentin bond strength. Ultrastructure of the resin-dentin interface identified presence of calcium phosphate within dentinal tubules. Laser treatment did not affect hybrid layer ultrastructure. Both treatment modalities (intratubular CaP occlusion and laser) had no influence on gelatinolytic activity within hybrid layers. CONCLUSION: Although intratubular CaP occlusion and laser treatment were effective in reducing dentin permeability, they did not affect bond strength, interfacial ultrastructure and gelatinolytic activity within hybrid layers. CLINICAL RELEVANCE: Treatment of etched dentin with Nd:YAG Laser at 60 mJ does not adversely affect collagen ultrastructure and gelatinolytic activity within the hybrid layer. The application of a calcium phosphate-based desensitiser to etch dentin does not affect dentin bond strength.

Randomized in situ trial on the efficacy of Carbopol in enhancing fluoride / stannous anti-erosive properties.

OBJECTIVE: To evaluate if the bioadhesive polymer (Carbopol 980) could potentiate the protective effect of sodium fluoride with stannous chloride (FS) solution on the control of enamel erosive wear. METHODS: Cylindrical bovine enamel specimens were polished and randomly allocated into three groups (n = 60): FS (500 ppm F- +800 ppm Sn2+ - positive control), FS + Carbopol (0.1% Carbopol), and ultrapure water (negative control). A randomized double-blind cross-over in situ model with three phases was used. In each phase, volunteers (n = 15) used a palatal appliance containing 4 specimens: two were submitted to an erosion model (2 h of pellicle formation; immersion in 1% citric acid, pH 2.3, for 5 min, 4x/day; 1 h intervals of saliva exposure; and treatment with the test solutions for 1 min, 2x/day). Besides erosion, the other two specimens were also subjected to abrasion (2x/day, 15 s) with active electric toothbrush, before the treatment with the solutions. After 5 days, enamel surface loss (µm) was evaluated by profilometry. Data were analyzed by two-way RM-ANOVA and Tukey tests (5%). RESULTS: There were significant differences for both challenge and treatment factors. Erosion/abrasion challenge resulted in significantly higher enamel loss than erosion only (p < 0.05). The surface loss values for the erosion/remineralization model were (means ±â€¯SL): C = 14.7 ±â€¯5.8b; FS = 9.0 ±â€¯7.5ab; FS + Carbopol = 5.9 ±â€¯3.8a; and for erosion/abrasion: C = 26.6 ±â€¯10.1c; FS = 15.0 ±â€¯8.8b; FS + Carbopol = 12.3 ±â€¯7.9ab. CONCLUSION: The association of Carbopol to the FS solution significantly protected the enamel against erosive wear, but it was not significantly superior to FS only. CLINICAL SIGNIFICANCE: Under highly erosive and abrasive conditions, rinsing with solutions containing sodium fluoride plus stannous chloride, associated or not with the Carbopol polymer, is an effective approach to control enamel erosive wear.