Bleaching as a complement to fluoride-enhanced remineralization or resin infiltration in masking white spot lesions.

OBJECTIVE: There are many suitable strategies for addressing caries, which is an ongoing worldwide problem. Although white spot lesions (WSLs) can be either remineralized naturally or treated with non- or micro-invasive strategies, their whitish and opaque appearance may persist. To evaluate the effects of tooth bleaching as a complement to fluoride-enhanced remineralization or resin infiltration in masking WSLs, as well as in enamel surface roughness relative to that of the adjacent enamel. METHODOLOGY: Flattened rectangular bovine enamel fragments (6×3×~2.9 mm length, width and thickness) were divided into six groups (L/N, F/N, F.BL/BL, I/N, I.BL/BL, N/N; n=15). Treatments applied to the 3×3 mm left half included: L (Lesion) - WSL simulation with 50 mM acetate buffer, 96 hours, 37ºC; F (Fluoride) - WSL treatment with 2% NaF neutral gel, 1x/week, 8 weeks; I (Infiltration) - WSL treatment with H3PO4 37%/10 s; Icon®-Dry/30 s; Icon®-Infiltrant/3 min+1 min; N (Nothing) - sound enamel/control. Treatments applied to both halves after F and I included: BL (Bleaching) - Opalescence Boost 40%, 3×/20 min each; N (Nothing) - control. The differences in color (ΔE00, ΔL, Δa, Δb) and surface roughness (ΔRa) between the left and right halves were measured. Kruskal-Wallis/post-hoc tests were applied to ΔE00, ΔL, Δa and ΔRa, and 1-way ANOVA/Tukey tests to Δb (α=0.05). RESULTS: The factor under study significantly influenced ΔE00 (p=0.0001), ΔL (p=0.0024), Δb (p=0.0015), and ΔRa (p<0.001), but not Δa (p=0.1592). Both fluoride-enhanced remineralization and resin infiltration were able to mask WSL, regardless of subsequent bleaching. However, when bleaching was performed, ΔE00 median values did not exceed the acceptability threshold for color difference. Only resin infiltration reduced ΔRa between WSL and the adjacent enamel. CONCLUSIONS: Both remineralization and infiltration, particularly if complemented by bleaching, fostered satisfactory esthetic results. Only infiltration without bleaching led to really good results in surface roughness.

Influence of different ultra-soft toothbrushes on erosive tooth wear.

OBJECTIVE: To investigate the influence of different ultra-soft toothbrushes on the progression of erosive tooth wear (ETW). METHODS: Bovine enamel and dentin specimens (n = 10) were submitted to a 5-day erosive-abrasive cycling model (0.3% citric acid for 5 min, artificial saliva for 60 min, 4x/day). Toothbrushing was carried out 2x/day for 15 s, with the different toothbrushes tested (A- Edel White: flexible handle, tapered bristles; B- Oral-B Gengiva Detox: regular handle, criss-cross tapered bristles; C- Colgate Gengiva Therapy: flexible handle, tapered bristles, high tuft density; d- Oral-B Expert Gengiva Sensi: regular handle, round end bristles, high tuft density; E- Oral-B Indicator Plus: soft brush, round end bristles (control). Surface loss (SL, in µm) was assessed by optical profilometry. The toothbrush characteristics were evaluated by a surgical microscope. Data were statistically analyzed (α=0.05). RESULTS: For enamel, toothbrush C showed the highest SL (means±SD: 9.86 ± 1.28) and it did not differ significantly from A (8.60 ± 0.50), both with flexible handles. The lowest SL was observed for the toothbrush Control E (6.76 ± 0.63), which differed significantly from A and C, but not from the other toothbrushes. For dentin, the highest SL was found for toothbrush D (6.97 ± 1.05) and it did not differ significantly from E (6.23 ± 0.71). The lowest SL was observed for B (4.61 ± 0.71) and C (4.85 + 0.83), without significant differences from A (5.01 ± 1.24). CONCLUSIONS: The ultra-soft toothbrushes had different impacts on the progression of ETW on the dental substrates. On enamel, higher ETW values were observed for the flexible handle toothbrushes, while for dentin, round-end bristles (ultra-soft and soft) caused more ETW. CLINICAL SIGNIFICANCE: Knowledge about the effect of different ultra-soft toothbrushes on ETW can help clinicians to recommend the most suitable types for their patients, bearing in mind that toothbrushes can impact enamel and dentin differently.

Análise morfométrica maxilar aplicada a osteotomia Le Fort I / Morphometric analysis of maxilla applied to Le Fort I osteotomy

Introdução: A osteotomia Le Fort I é uma técnica cirúrgica utilizada para a correção de deformidades dentofaciais e para que ocorra a mobilização da maxila é necessária a disjunção da sutura pterigomaxilar. Durante esse procedimento, complicações podem ocorrer, como hemorragia resultante da injúria da artéria maxilar interna ou de seus ramos terminais, na qual a artéria palatina descendente é mais comum de ser lesionada. Objetivo: O objetivo deste estudo foi contribuir para o estabelecimento de parâmetros cirúrgicos seguros para realizar osteotomia le fort I com disjunção pterigomaxilar, por meio da obtenção de medidas das regiões maxilar e pterigomaxilar. Material e métodos: Foram selecionados quarenta crânios secos dos sexos masculino e feminino do Departamento de Anatomia de uma instituição pública e realizadas as medidas pelo método de inspeção direta com o uso de um paquímetro digital Mitutoyo® e um compasso Staedtler®. Foram medidas a altura e espessura da junção pterigomaxilar (JPM), a distância da sutura pterigomaxilar até o pilar zigomático, a distância desde o ponto mais inferior da sutura pterigomaxilar até a fissura orbital inferior (FOI), a extensão da parede lateral da cavidade nasal até o canal palatino descendente e o comprimento do septo nasal, bilateralmente. Para análise estatística dos resultados, utilizou-se o teste t para amostras independentes, com nível de significância de 5%. Resultados: Observou-se que para o lado direito, as médias das respectivas medidas foram de 14,88mm, 9,17mm, 27,60mm, 34,47mm e 36,86; e o lado esquerdo, as médias foram, respectivamente, 15,18mm, 9,08mm, 26,50mm, 34,70mm e 36,02mm. O valor médio do comprimento do septo nasal foi de 49,10mm. Conclusão: com base nos valores obtidos é possível estabelecer parâmetros operatórios para a osteotomia Le Fort I.

Introduction: The Le Fort I osteotomy is a surgical technique used for correction of dentofacial deformities and dislocation of the pterygomaxillary suture for mobilization of maxilla. During this procedure, complications may happen, such as hemorrhage resulting from the injury of the internal maxillary artery or its terminal branches, in which the descending palatine artery is more common to be injured. Objective: The aim of this study was to contribute for establishment of safe surgical parameters to improve osteotomy with pterygomaxillary disjunction, through the measurement of the maxillary and pterygomaxillary regions. Material and Method: Forty dry skulls (male and female) of the Department of Anatomy of a public institution were selected and the measurements were made by the direct inspection method using a Mitutoyo® digital caliper and a Staedtler compass ®. The height and thickness of the pterygomaxillary junction, the distance from the pterygomaxillary suture to the zygomatic pillar, the distance from the lower point of the pterygomaxillary suture to the inferior orbital fissure, the extension of the lateral wall of the nasal cavity to the descending palatine canal, and the length of the nasal septum, bilaterally, were measured. For the statistical analysis of the results, the t-test was used for independent samples, with a significance level of 5%. Results: We found that on the right side, the averages of the respective measurements were 14.88mm, 9.17mm, 27.60mm, 34.47mm and 36.86; and on the left side, the averages were, respectively, 15.18mm, 9.08mm, 26.50mm, 34.70mm and 36.02mm. The mean value of nasal septum length was 49.10 mm. Conclusion: Based on the values obtained it is possible to establish operative parameters for the Le Fort I osteotomy.