Does polishing of bleached enamel affect roughness and tooth color stability after exposure to coffee?

OBJECTIVE: This laboratory randomized study was designed to evaluate the effect of polishing on roughness and color stability of bleached teeth after coffee immersion. MATERIALS AND METHODS: Ninety bovine crowns were randomly allocated to six groups (n = 15), according to bleaching protocols: At-home: standard protocol using 10% hydrogen peroxide (HP) or In-office: standard protocol using 35% HP; and with polishing protocols: (1) no polishing, (2) bleached enamel polished with #0.5 µm or (3) #2-4 µm diamond particles grit pastes. Samples were daily immersed into coffee solution for 45 min followed by mechanical brushing simulation (30 s) for 30 days. The surface roughness (Ra) and color alteration, expressed by ΔEab , ΔE00 , and whitening index (WI) were analyzed at baseline, after bleaching/polishing protocols and after coffee solution staining. The surface from each group was examined using a scanning electron microscope. Data were analyzed by two-way repeated measure analysis of variance followed by the Tukey test (α = 0.05). RESULTS: Staining increases Ra, ΔEab , ΔE00 , and decreases WI values. Polishing after bleaching did not prevent staining, however, tooth polished with #0.5 µ-grit polishing paste showed better performance than #2-4 µ-grit (ΔEab : p = 0.001/ΔE00 : p = 0.003). Scanning electron microscope revealed a more irregular surface after coffee staining for all groups regardless bleaching/polishing protocols. CONCLUSIONS: Using #0.5 µ-grit diamond paste to polish 35%HP in-office bleached enamel reduces the roughness and tooth staining. However, polishing after 10%HP at-home bleached enamel neither affects roughness nor improves tooth color stability after exposure to coffee. CLINICAL SIGNIFICANCE: Polishing after at-home bleaching does not have benefits but after 35% hydrogen peroxide in-office bleaching, the polishing with #0.5 µ-grit polishing paste is indicated to reduce roughness and the tooth staining over time.

Can ozone or violet light improve the color change or physicochemical properties of hydrogen peroxide-bleached tooth?

This study investigated the bleaching effectiveness and the physicochemical effects on enamel of violet light and ozone, associate or not to hydrogen peroxide, compared to 35%-hydrogen peroxide. Enamel-dentin blocks from human molars were randomly allocated to receive one of the following bleaching protocols (n=15): (HP) 35%-hydrogen peroxide, (VL) violet light, (OZ) ozone, the association between hydrogen peroxide with ozone (OZ+HP) or violet light (VL+HP). All protocols were performed in two sessions with a 48h interval. Color (spectrophotometer) and mineral composition (Raman spectroscopy) were measured before and after the bleaching. Color changes were calculated by ΔEab, ΔE00, and whitening index (WI). The surface roughness was measured with an atomic force microscope. Data were analyzed by One-way or Two-way repeated measure ANOVA followed by the Tukey's test (α = 0.05). The lowest color change values (either measured by WI, ΔEab, or ΔE00) were observed for VL and OZ used with no HP. Violet light associate with HP was unable to improve the color changes observed for the peroxide alone, in combination with OZ and HP, the highest color changes were verified. Regardless of bleaching protocol, the bleached enamel presented higher contents of PO4 and CO3 -2 than those observed at baseline. All bleaching protocols resulted in similar enamel surface roughness. Both the VL and the OZ caused reduced effects on the enamel color change when used alone. The ozone therapy improved the bleaching effect in the group that received the association of HP.

Can ozone or violet light improve the color change or physicochemical properties of hydrogen peroxide-bleached tooth?

Abstract: This study investigated the bleaching effectiveness and the physicochemical effects on enamel of violet light and ozone, associate or not to hydrogen peroxide, compared to 35%-hydrogen peroxide. Enamel-dentin blocks from human molars were randomly allocated to receive one of the following bleaching protocols (n=15): (HP) 35%-hydrogen peroxide, (VL) violet light, (OZ) ozone, the association between hydrogen peroxide with ozone (OZ+HP) or violet light (VL+HP). All protocols were performed in two sessions with a 48h interval. Color (spectrophotometer) and mineral composition (Raman spectroscopy) were measured before and after the bleaching. Color changes were calculated by ΔEab, ΔE00, and whitening index (WI). The surface roughness was measured with an atomic force microscope. Data were analyzed by One-way or Two-way repeated measure ANOVA followed by the Tukey's test (α = 0.05). The lowest color change values (either measured by WI, ΔEab, or ΔE00) were observed for VL and OZ used with no HP. Violet light associate with HP was unable to improve the color changes observed for the peroxide alone, in combination with OZ and HP, the highest color changes were verified. Regardless of bleaching protocol, the bleached enamel presented higher contents of PO4 and CO3 -2 than those observed at baseline. All bleaching protocols resulted in similar enamel surface roughness. Both the VL and the OZ caused reduced effects on the enamel color change when used alone. The ozone therapy improved the bleaching effect in the group that received the association of HP.

Resumo O objetivo deste estudo foi avaliar o efeito clareador e físico-químico no esmalte de luz violeta e ozônio, associado ou não ao peróxido de hidrogênio, comparado a 35% de peróxido de hidrogênio. Blocos de esmalte-dentina de molares humanos foram alocados aleatoriamente para receber um dos seguintes protocolos de clareamento (n = 15): (HP) peróxido de hidrogênio a 35%, (VL) luz violeta, (OZ) ozônio, a associação entre peróxido de hidrogênio com ozônio (HP+OZ) ou luz violeta (HP+VL). Todos os protocolos foram realizados em duas sessões, com intervalo de 48 horas entre eles. A cor (espectrofotômetro) e a composição mineral (espectroscopia Raman) do dente foram medidas antes e após os procedimentos de clareamento. As alterações de cor foram calculadas por ΔEab e ΔE00, e o índice de brancura foram calculados. A rugosidade da superfície das amostras clareadas foi medida por microscópio de força atômica. Os dados foram analisados por ANOVA One way ou ANOVA two way de medidas repetidas seguida pelo teste de Tukey (α = 0,05). Os menores valores de alterações de cor (medidos por WI, ΔEab ou ΔE00) foram observados para VL e OZ usados na ausência de HP. VL associada ao HP não foi capaz de melhorar as alterações de cor observadas com o uso do HP, mas a combinação de OZ e HP produz as maiores alterações de cor. Independentemente do protocolo de clareamento, o esmalte clareado apresentou maiores teores de PO4 e CO3 -2 do que os observados inicialmente. Não foi observada diferença significativa entre os protocolos de clareamento testados em relação à rugosidade da superfície do esmalte. É possível concluir que a VL ou o OZ tiveram efeitos reduzidos na mudança de cor do esmalte quando usados sozinhos. A terapia com OZ melhorou o efeito clareador do HP.

Oxygen Inhibition of Surface Composites and Its Correlation with Degree of Conversion and Color Stability.

This study investigated the effects of oxygen inhibition and finishing/polishing procedures on the composite resin properties. One bulk-fill and two conventional composite resins (nanoparticle and microhybrid) were evaluated. Specimens were prepared using 4 surface treatments: control, no treatment; Gly, oxygen inhibition with glycerin; FP, finishing and polishing; Gly + FP, glycerin followed by finishing and polishing. The degree of conversion (DC) was measured using Fourier Transformed Infrared Spectroscopy (FTIR) immediately and after 15 days (n=5). Color stability (ΔEab, and ΔE00) and opacity were evaluated using a spectrophotometer after 15 days of immersion in coffee, using the CIELAB system (n=5). Data were analyzed by two-way ANOVA and Tukey tests (α=0.05) and opacity by two-way repeated-measures ANOVA. Glycerin usage increased significantly the DC however had no influence on the ΔEab, ΔE00 and, opacity values. Finishing and polishing reduced ΔEab and ΔE00 values, regardless of composite resins. Microhybrid showed higher opacity, followed by the nanoparticle and bulk fill, regardless of surface treatment. Post-polymerization polishing procedures resulted in lower conversion than using an oxygen inhibitor agent (Gly condition), but similar staining caused by coffee.

Acupuncture in Temporomandibular Disorders Painful Symptomatology: An Evidence-Based Case Report.

Temporomandibular dysfunction (TMD) is complex and multifactorial. Its etiology involves various factors, such as malocclusion, psychological patterns, parafunctional habits, and the temporomandibular joint anatomy. Symptoms include myofascial pain, joint clicking, mouth opening limitation, headaches, earaches, and neck pain, comprising one of the greatest causes of nondental pain. Acupuncture has been used to treat these conditions by acting locally both in muscle relaxation and pain management as well as reaching physical, mental, and emotional balance. The aim of this study is to present a brief literature review reporting the efficacy of acupuncture on TMDs and a case report in which the painful symptomatology of TMD was treated with a systemic protocol, based on scientific evidence and concepts of traditional Chinese medicine. Acupuncture may be a complementary treatment for TMD, and in this case report, it eliminated the patient's painful symptomatology.